231 results on '"S. Guenther"'
Search Results
2. Practical Preservation: The PREMIS Experience.
- Author
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Priscilla Caplan and Rebecca S. Guenther
- Published
- 2005
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3. Host-Pathogen Coevolution: The Selective Advantage of Bacillus thuringiensis Virulence and Its Cry Toxin Genes.
- Author
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Leila Masri, Antoine Branca, Anna E Sheppard, Andrei Papkou, David Laehnemann, Patrick S Guenther, Swantje Prahl, Manja Saebelfeld, Jacqueline Hollensteiner, Heiko Liesegang, Elzbieta Brzuszkiewicz, Rolf Daniel, Nicolaas K Michiels, Rebecca D Schulte, Joachim Kurtz, Philip Rosenstiel, Arndt Telschow, Erich Bornberg-Bauer, and Hinrich Schulenburg
- Subjects
Biology (General) ,QH301-705.5 - Abstract
Reciprocal coevolution between host and pathogen is widely seen as a major driver of evolution and biological innovation. Yet, to date, the underlying genetic mechanisms and associated trait functions that are unique to rapid coevolutionary change are generally unknown. We here combined experimental evolution of the bacterial biocontrol agent Bacillus thuringiensis and its nematode host Caenorhabditis elegans with large-scale phenotyping, whole genome analysis, and functional genetics to demonstrate the selective benefit of pathogen virulence and the underlying toxin genes during the adaptation process. We show that: (i) high virulence was specifically favoured during pathogen-host coevolution rather than pathogen one-sided adaptation to a nonchanging host or to an environment without host; (ii) the pathogen genotype BT-679 with known nematocidal toxin genes and high virulence specifically swept to fixation in all of the independent replicate populations under coevolution but only some under one-sided adaptation; (iii) high virulence in the BT-679-dominated populations correlated with elevated copy numbers of the plasmid containing the nematocidal toxin genes; (iv) loss of virulence in a toxin-plasmid lacking BT-679 isolate was reconstituted by genetic reintroduction or external addition of the toxins. We conclude that sustained coevolution is distinct from unidirectional selection in shaping the pathogen's genome and life history characteristics. To our knowledge, this study is the first to characterize the pathogen genes involved in coevolutionary adaptation in an animal host-pathogen interaction system.
- Published
- 2015
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4. Battle of the Buzzwords: Flexibility vs. Interoperability When Implementing PREMIS in METS.
- Author
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Rebecca S. Guenther
- Published
- 2008
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5. Split-Dose Cisplatin in Patients With Locally Advanced or Metastatic Urothelial Carcinoma: A Systematic Literature Review and Network Meta-Analysis.
- Author
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O'Dwyer R, Musat MG, Gulas I, Hubscher E, Moradian H, Guenther S, Kearney M, and Sridhar SS
- Subjects
- Humans, Urologic Neoplasms drug therapy, Urologic Neoplasms pathology, Gemcitabine, Deoxycytidine analogs & derivatives, Deoxycytidine administration & dosage, Deoxycytidine adverse effects, Deoxycytidine therapeutic use, Carcinoma, Transitional Cell drug therapy, Carcinoma, Transitional Cell secondary, Carcinoma, Transitional Cell pathology, Carboplatin administration & dosage, Carboplatin adverse effects, Treatment Outcome, Drug Administration Schedule, Doxorubicin administration & dosage, Doxorubicin adverse effects, Methotrexate administration & dosage, Methotrexate therapeutic use, Vinblastine administration & dosage, Vinblastine adverse effects, Vinblastine therapeutic use, Progression-Free Survival, Cisplatin administration & dosage, Cisplatin adverse effects, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Antineoplastic Combined Chemotherapy Protocols administration & dosage, Antineoplastic Combined Chemotherapy Protocols adverse effects, Network Meta-Analysis
- Abstract
Background: Gemcitabine plus cisplatin (GC) is a highly active and commonly used regimen in locally advanced/metastatic urothelial carcinoma (la/mUC). With GC, cisplatin is dosed at 70 mg/m
2 on day 1 of a 3-week cycle; however, for many patients, impaired renal or cardiac function, neuropathy, or poor performance status (PS) can preclude the use of cisplatin. A promising alternative is split-dose GC, in which the cisplatin dose is divided over 2 days., Methods: We conducted a systematic literature review (SLR) and network meta-analysis (NMA) to better understand treatment patterns and comparative effectiveness and safety of split-dose GC vs gemcitabine plus carboplatin (GCa), GC, and methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC)., Results: Among 120 identified studies, 16 studies representing 1,767 patients included split-dose GC. Common reasons for choosing split-dose GC were impaired renal function, age > 70 years, comorbidities, and physician preference. Split-dose GC had objective response rates (ORRs) of 39%-80%, median progression-free survival (PFS) of 3.5-9.9 months, and median overall survival (OS) of 8.5-18.1 months. Discontinuation rates due to adverse events were 5%-38%. In the NMA, ORR with split-dose GC was significantly higher than with GCa. PFS and OS for split-dose GC were similar to that observed with the other regimens (GCa, GC, and MVAC)., Conclusions: This is the first SLR and NMA of split-dose GC in la/mUC. Despite heterogeneity in the limited studies included, split-dose GC demonstrated comparable effectiveness and safety profile to those seen with other regimens. Split-dose GC thus has the potential to extend the la/mUC population eligible to receive cisplatin-based regimens and warrants further prospective study., Competing Interests: Disclosure Richard O'Dwyer has received support for travel and attending meetings from Pfizer and research funding from the healthcare business of Merck KGaA, Darmstadt, Germany. Mihaela G. Musat and Hoora Moradian are employees of Cytel, which was contracted for this work by the healthcare business of Merck KGaA, Darmstadt, Germany. Ioana Gulas and Elizabeth Hubscher were employees of Cytel at the time of the study. Silke Guenther was an employee of the healthcare business of Merck KGaA, Darmstadt, Germany, at the time of the study. Mairead Kearney is an employee of the healthcare business of Merck KGaA, Darmstadt, Germany. Srikala S. Sridhar has served in consulting or advisory roles for Astellas Pharma, AstraZeneca, Bayer, Bristol Myers Squibb, Janssen, Merck & Co, Kenilworth, NJ, Pfizer, Roche/Genentech, and Seagen and has received institutional research funding from the healthcare business of Merck KGaA, Darmstadt, Germany., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2024
- Full Text
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6. Electroencephalography in emerging viral infections: Lessons learned from implementing an EEG unit in a Lassa fever isolation ward in Nigeria.
- Author
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Mueller HCS, Erameh CO, Gelderblom M, Edeawe OI, Akpasubi OG, Ekoyata EU, Aiterebhe UM, Okoeguale J, Guenther S, Oestereich L, Ramharter M, Okogbenin S, and Omansen T
- Subjects
- Humans, Nigeria, Lassa virus isolation & purification, Communicable Diseases, Emerging diagnosis, Communicable Diseases, Emerging virology, Male, Female, Adult, Lassa Fever diagnosis, Electroencephalography methods
- Abstract
Electroencephalography (EEG) has been used for almost a century in well-equipped medical centers to facilitate the diagnosis of epilepsy and other brain disorders. Lassa fever (LF) and other emerging viral infections (EVI) are known to cause neurological complications, including meningitis, seizures, and encephalopathy, though to date it remains unclear whether these are secondary to metabolic disturbances caused by the disease or by direct involvement of the central nervous system (CNS). To better characterize how Lassa virus (LASV) affects the CNS, we established an EEG diagnostic unit in the LF isolation ward at Irrua Specialist Teaching Hospital in Edo State, Nigeria. Here, we report on the specific difficulties to successful implementation of EEG in this highly challenging setting. Technical artefacts due to electrical interferences and interrupted power supply, artefacts deriving from a partly improvised EEG setup within a high consequence pathogen isolation ward, and environmental factors, such as heat in the endemic West African setting are among the main difficulties encountered when setting up this diagnostic facility. It takes experienced neurophysiologists to distinguish such artefacts from actual EEG abnormalities as many of them are not commonly encountered to this extent in well-equipped EEG laboratories and can easily be confused with pathologies. The EEG recording process is further complicated by biosafety considerations and the necessity of wearing extensive personal protective equipment. Nevertheless, with the help of experienced neurophysiologists, it is possible to correctly set up the facility and interpret recordings. Taking the above into consideration, EEG is valuable in identifying CNS involvement in emerging infections, particularly regarding assessment of encephalitis, differential diagnosis of impaired consciousness and treatment adjustment in patients with symptomatic seizures. Although highly challenging under these circumstances, EEG can be an important, noninvasive diagnostic tool for neurological complications in EVI where other more advanced imaging modalities are not available., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Mueller et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2024
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7. The heart is a resident tissue for hematopoietic stem and progenitor cells in zebrafish.
- Author
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Bornhorst D, Hejjaji AV, Steuter L, Woodhead NM, Maier P, Gentile A, Alhajkadour A, Santis Larrain O, Weber M, Kikhi K, Guenther S, Huisken J, Tamplin OJ, Stainier DYR, and Gunawan F
- Subjects
- Animals, Hematopoiesis physiology, Heart physiology, Vascular Cell Adhesion Molecule-1 metabolism, Vascular Cell Adhesion Molecule-1 genetics, Zebrafish Proteins metabolism, Zebrafish Proteins genetics, Single-Cell Analysis, Cell Lineage, Erythropoiesis physiology, Animals, Genetically Modified, Zebrafish, Hematopoietic Stem Cells cytology, Hematopoietic Stem Cells metabolism, Endocardium cytology, Endocardium metabolism
- Abstract
The contribution of endocardial cells (EdCs) to the hematopoietic lineages has been strongly debated. Here, we provide evidence that in zebrafish, the endocardium gives rise to and maintains a stable population of hematopoietic cells. Using single-cell sequencing, we identify an endocardial subpopulation expressing enriched levels of hematopoietic-promoting genes. High-resolution microscopy and photoconversion tracing experiments uncover hematopoietic cells, mainly hematopoietic stem and progenitor cells (HSPCs)/megakaryocyte-erythroid precursors (MEPs), derived from EdCs as well as the dorsal aorta stably attached to the endocardium. Emergence of HSPCs/MEPs in hearts cultured ex vivo without external hematopoietic sources, as well as longitudinal imaging of the beating heart using light sheet microscopy, support endocardial contribution to hematopoiesis. Maintenance of these hematopoietic cells depends on the adhesion factors Integrin α4 and Vcam1 but is at least partly independent of cardiac trabeculation or shear stress. Finally, blocking primitive erythropoiesis increases cardiac-residing hematopoietic cells, suggesting that the endocardium is a hematopoietic reservoir. Altogether, these studies uncover the endocardium as a resident tissue for HSPCs/MEPs and a de novo source of hematopoietic cells., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
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8. Hypothermic oxygenated perfusion of the donor heart in heart transplantation: the short-term outcome from a randomised, controlled, open-label, multicentre clinical trial.
- Author
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Rega F, Lebreton G, Para M, Michel S, Schramm R, Begot E, Vandendriessche K, Kamla C, Gerosa G, Berman M, Boeken U, Clark S, Ranasinghe A, Ius F, Forteza A, Pivodic A, Hennig F, Guenther S, Zuckermann A, Knosalla C, Dellgren G, and Wallinder A
- Subjects
- Humans, Middle Aged, Male, Female, Adult, Aged, Primary Graft Dysfunction prevention & control, Young Adult, Tissue Donors, Adolescent, Treatment Outcome, Graft Rejection prevention & control, Heart Transplantation, Organ Preservation methods, Perfusion methods
- Abstract
Background: Static cold storage (SCS) remains the gold standard for preserving donor hearts before transplantation but is associated with ischaemia, anaerobic metabolism, and organ injuries, leading to patient morbidity and mortality. We aimed to evaluate whether continuous, hypothermic oxygenated machine perfusion (HOPE) of the donor heart is safe and superior compared with SCS., Methods: We performed a multinational, multicentre, randomised, controlled, open-label clinical trial with a superiority design at 15 transplant centres across eight European countries. Adult candidates for heart transplantation were eligible and randomly assigned in a 1:1 ratio. Donor inclusion criteria were age 18-70 years with no previous sternotomy and donation after brain death. In the treatment group, the preservation protocol involved the use of a portable machine perfusion system ensuring HOPE of the resting donor heart. The donor hearts in the control group underwent ischaemic SCS according to standard practices. The primary outcome was time to first event of a composite of either cardiac-related death, moderate or severe primary graft dysfunction (PGD) of the left ventricle, PGD of the right ventricle, acute cellular rejection at least grade 2R, or graft failure (with use of mechanical circulatory support or re-transplantation) within 30 days after transplantation. We included all patients who were randomly assigned, fulfilled inclusion and exclusion criteria, and received a transplant in the primary analysis and all patients who were randomly assigned and received a transplant in the safety analyses. This trial was registered with ClicalTrials.gov (NCT03991923) and is ongoing., Findings: A total of 229 patients were enrolled between Nov 25, 2020, and May 19, 2023. The primary analysis population included 204 patients who received a transplant. There were no patients who received a transplant lost to follow-up. All 100 donor hearts preserved with HOPE were transplantable after perfusion. The primary endpoint was registered in 19 (19%) of 101 patients in the HOPE group and 31 (30%) of 103 patients in the SCS group, corresponding to a risk reduction of 44% (hazard ratio 0·56; 95% CI 0·32-0·99; log-rank test p=0·059). PGD was the primary outcome event in 11 (11%) patients in the HOPE group and 29 (28%) in the SCS group (risk ratio 0·39; 95% CI 0·20-0·73). In the HOPE group, 63 (65%) patients had a reported serious adverse event (158 events) versus 87 (70%; 222 events) in the SCS group. Major adverse cardiac transplant events were reported in 18 (18%) and 33 (32%) patients in the HOPE and SCS group (risk ratio 0·56; 95% CI 0·34-0·92)., Interpretation: Although there was not a significant difference in the primary endpoint, the 44% risk reduction associated with HOPE was suggested to be a clinically meaningful benefit. Post-transplant complications, measured as major adverse cardiac transplant events, were reduced. Analysis of secondary outcomes suggested that HOPE was beneficial in reducing primary graft dysfunction. HOPE in donor heart preservation addresses the existing challenges associated with graft preservation and the increasing complexity of donors and heart transplantation recipients. Future investigation will help to further elucidate the benefit of HOPE., Funding: XVIVO Perfusion., Competing Interests: Declaration of interests The sponsor provided the investigational devices and financial support for trial-specific investigational site costs to all participating centres. FR reports institutional research grants from XVIVO outside of the submitted work and receiving speakers fees from Atricure. GL reports receiving study materials from XVIVO as investigator in another clinical trial. SM reports research grants from German Center for Lung Research and German Research Foundation and honoraria from Berlin Heart. GD reports research grants from Astellas and Abbot and being a programme chair for ISHLT and a board member of XVIVO. AW is employed by the trial sponsor and may retain stock or stock options. All other authors declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved, including those for text and data mining, AI training, and similar technologies.)
- Published
- 2024
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9. Image classification and reconstruction from low-density EEG.
- Author
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Guenther S, Kosmyna N, and Maes P
- Subjects
- Humans, Adult, Female, Male, Brain Mapping methods, Young Adult, Photic Stimulation, Magnetic Resonance Imaging methods, Algorithms, Electroencephalography methods, Brain physiology, Brain diagnostic imaging, Image Processing, Computer-Assisted methods
- Abstract
Recent advances in visual decoding have enabled the classification and reconstruction of perceived images from the brain. However, previous approaches have predominantly relied on stationary, costly equipment like fMRI or high-density EEG, limiting the real-world availability and applicability of such projects. Additionally, several EEG-based paradigms have utilized artifactual, rather than stimulus-related information yielding flawed classification and reconstruction results. Our goal was to reduce the cost of the decoding paradigm, while increasing its flexibility. Therefore, we investigated whether the classification of an image category and the reconstruction of the image itself is possible from the visually evoked brain activity measured by a portable, 8-channel EEG. To compensate for the low electrode count and to avoid flawed predictions, we designed a theory-guided EEG setup and created a new experiment to obtain a dataset from 9 subjects. We compared five contemporary classification models with our setup reaching an average accuracy of 34.4% for 20 image classes on hold-out test recordings. For the reconstruction, the top-performing model was used as an EEG-encoder which was combined with a pretrained latent diffusion model via double-conditioning. After fine-tuning, we reconstructed images from the test set with a 1000 trial 50-class top-1 accuracy of 35.3%. While not reaching the same performance as MRI-based paradigms on unseen stimuli, our approach greatly improved the affordability and mobility of the visual decoding technology., (© 2024. The Author(s).)
- Published
- 2024
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10. SIRT7 promotes lung cancer progression by destabilizing the tumor suppressor ARF.
- Author
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Kumari P, Tarighi S, Fuchshuber E, Li L, Fernández-Duran I, Wang M, Ayoson J, Castelló-García JM, Gámez-García A, Espinosa-Alcantud M, Sreenivasan K, Guenther S, Olivella M, Savai R, Yue S, Vaquero A, Braun T, and Ianni A
- Subjects
- Humans, Animals, Mice, Gene Expression Regulation, Neoplastic, Cell Line, Tumor, Sirtuins metabolism, Sirtuins genetics, Lung Neoplasms genetics, Lung Neoplasms metabolism, Lung Neoplasms pathology, Carcinoma, Non-Small-Cell Lung genetics, Carcinoma, Non-Small-Cell Lung metabolism, Carcinoma, Non-Small-Cell Lung pathology, Cell Proliferation, Disease Progression
- Abstract
Sirtuin 7 (SIRT7) is a member of the mammalian family of nicotinamide adenine dinucleotide (NAD
+ )-dependent histone/protein deacetylases, known as sirtuins. It acts as a potent oncogene in numerous malignancies, but the molecular mechanisms employed by SIRT7 to sustain lung cancer progression remain largely uncharacterized. We demonstrate that SIRT7 exerts oncogenic functions in lung cancer cells by destabilizing the tumor suppressor alternative reading frame (ARF). SIRT7 directly interacts with ARF and prevents binding of ARF to nucleophosmin, thereby promoting proteasomal-dependent degradation of ARF. We show that SIRT7-mediated degradation of ARF increases expression of protumorigenic genes and stimulates proliferation of non-small-cell lung cancer (NSCLC) cells both in vitro and in vivo in a mouse xenograft model. Bioinformatics analysis of transcriptome data from human lung adenocarcinomas revealed a correlation between SIRT7 expression and increased activity of genes normally repressed by ARF. We propose that disruption of SIRT7-ARF signaling stabilizes ARF and thus attenuates cancer cell proliferation, offering a strategy to mitigate NSCLC progression., Competing Interests: Competing interests statement:The authors declare no competing interest.- Published
- 2024
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11. Temperatures above 37°C increase virulence of a convergent Klebsiella pneumoniae sequence type 307 strain.
- Author
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Müller JU, Schwabe M, Swiatek LS, Heiden SE, Schlüter R, Sittner M, Bohnert JA, Becker K, Idelevich EA, Guenther S, Eger E, and Schaufler K
- Subjects
- Virulence genetics, Animals, Larva microbiology, Plasmids genetics, Moths microbiology, Humans, Virulence Factors genetics, Bacterial Proteins genetics, Bacterial Proteins metabolism, Lepidoptera microbiology, Viscosity, Phenotype, Gene Expression Profiling, Klebsiella pneumoniae genetics, Klebsiella pneumoniae pathogenicity, Klebsiella pneumoniae classification, Biofilms growth & development, Klebsiella Infections microbiology, Temperature
- Abstract
Background: Convergence of Klebsiella pneumoniae (KP) pathotypes has been increasingly reported in recent years. These pathogens combine features of both multidrug-resistant and hypervirulent KP. However, clinically used indicators for hypervirulent KP identification, such as hypermucoviscosity, appear to be differentially expressed in convergent KP, potential outbreak clones are difficult to identify. We aimed to fill such knowledge gaps by investigating the temperature dependence of hypermucoviscosity and virulence in a convergent KP strain isolated during a clonal outbreak and belonging to the high-risk sequence type (ST)307., Methods: Hypermucoviscosity, biofilm formation, and mortality rates in Galleria mellonella larvae were examined at different temperatures (room temperature, 28°C, 37°C, 40°C and 42°C) and with various phenotypic experiments including electron microscopy. The underlying mechanisms of the phenotypic changes were explored via qPCR analysis to evaluate plasmid copy numbers, and transcriptomics., Results: Our results show a temperature-dependent switch above 37°C towards a hypermucoviscous phenotype, consistent with increased biofilm formation and in vivo mortality, possibly reflecting a bacterial response to fever-like conditions. Furthermore, we observed an increase in plasmid copy number for a hybrid plasmid harboring carbapenemase and rmpA genes. However, transcriptomic analysis revealed no changes in rmpA expression at higher temperatures, suggesting alternative regulatory pathways., Conclusion: This study not only elucidates the impact of elevated temperatures on hypermucoviscosity and virulence in convergent KP but also sheds light on previously unrecognized aspects of its adaptive behavior, underscoring its resilience to changing environments., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Müller, Schwabe, Swiatek, Heiden, Schlüter, Sittner, Bohnert, Becker, Idelevich, Guenther, Eger and Schaufler.)
- Published
- 2024
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12. egr3 is a mechanosensitive transcription factor gene required for cardiac valve morphogenesis.
- Author
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da Silva AR, Gunawan F, Boezio GLM, Faure E, Théron A, Avierinos JF, Lim S, Jha SG, Ramadass R, Guenther S, Looso M, Zaffran S, Juan T, and Stainier DYR
- Subjects
- Animals, Humans, Gene Expression Regulation, Developmental, Endothelial Cells metabolism, Mechanotransduction, Cellular, Swine, Zebrafish, Heart Valves metabolism, Heart Valves embryology, Zebrafish Proteins genetics, Zebrafish Proteins metabolism, Morphogenesis genetics, Early Growth Response Protein 3 metabolism, Early Growth Response Protein 3 genetics
- Abstract
Biomechanical forces, and their molecular transducers, including key mechanosensitive transcription factor genes, such as KLF2 , are required for cardiac valve morphogenesis. However, klf2 mutants fail to completely recapitulate the valveless phenotype observed under no-flow conditions. Here, we identify the transcription factor EGR3 as a conserved biomechanical force transducer critical for cardiac valve formation. We first show that egr3 null zebrafish display a complete and highly penetrant loss of valve leaflets, leading to severe blood regurgitation. Using tissue-specific loss- and gain-of-function tools, we find that during cardiac valve formation, Egr3 functions cell-autonomously in endothelial cells, and identify one of its effectors, the nuclear receptor Nr4a2b. We further find that mechanical forces up-regulate egr3 / EGR3 expression in the developing zebrafish heart and in porcine valvular endothelial cells, as well as during human aortic valve remodeling. Altogether, these findings reveal that EGR3 is necessary to transduce the biomechanical cues required for zebrafish cardiac valve morphogenesis, and potentially for pathological aortic valve remodeling in humans.
- Published
- 2024
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13. Exploring the Influence of Cold Plasma on Epidermal Melanogenesis In Situ and In Vitro.
- Author
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Hasse S, Sommer MC, Guenther S, Schulze C, Bekeschus S, and von Woedtke T
- Subjects
- Humans, Ultraviolet Rays, Skin Pigmentation drug effects, Skin Pigmentation radiation effects, Cells, Cultured, Reactive Oxygen Species metabolism, Biopsy, Melanogenesis, Melanins metabolism, Melanins biosynthesis, Melanocytes metabolism, Melanocytes drug effects, Plasma Gases pharmacology, Epidermis metabolism, Epidermis drug effects, Epidermis radiation effects
- Abstract
Epidermal melanin synthesis determines an individual's skin color. In humans, melanin is formed by melanocytes within the epidermis. The process of melanin synthesis strongly depends on a range of cellular factors, including the fine-tuned interplay with reactive oxygen species (ROS). In this context, a role of cold atmospheric plasma (CAP) on melanin synthesis was proposed due to its tunable ROS generation. Herein, the argon-driven plasma jet kINPen
® MED was employed, and its impact on melanin synthesis was evaluated by comparison with known stimulants such as the phosphodiesterase inhibitor IBMX and UV radiation. Different available model systems were employed, and the melanin content of both cultured human melanocytes (in vitro) and full-thickness human skin biopsies (in situ) were analyzed. A histochemical method detected melanin in skin tissue. Cellular melanin was measured by NIR autofluorescence using flow cytometry, and a highly sensitive HPLC-MS method was applied, which enabled the differentiation of eu- and pheomelanin by their degradation products. The melanin content in full-thickness human skin biopsies increased after repeated CAP exposure, while there were only minor effects in cultured melanocytes compared to UV radiation and IBMX treatment. Based on these findings, CAP does not appear to be a useful option for treating skin pigmentation disorders. On the other hand, the risk of hyperpigmentation as an adverse effect of CAP application for wound healing or other dermatological diseases seems to be neglectable.- Published
- 2024
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14. A brain-specific angiogenic mechanism enabled by tip cell specialization.
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Schevenels G, Cabochette P, America M, Vandenborne A, De Grande L, Guenther S, He L, Dieu M, Christou B, Vermeersch M, Germano RFV, Perez-Morga D, Renard P, Martin M, Vanlandewijck M, Betsholtz C, and Vanhollebeke B
- Subjects
- Animals, Basement Membrane metabolism, Blood-Brain Barrier metabolism, Blood-Brain Barrier cytology, Cell Movement, Collagen Type IV metabolism, CRISPR-Cas Systems genetics, Endothelial Cells metabolism, Endothelial Cells cytology, Meninges cytology, Meninges blood supply, Meninges metabolism, Organ Specificity, Wnt Proteins metabolism, Wnt Signaling Pathway, Zebrafish genetics, Zebrafish metabolism, Zebrafish Proteins metabolism, Zebrafish Proteins genetics, Brain cytology, Brain blood supply, Brain metabolism, Neovascularization, Physiologic
- Abstract
Vertebrate organs require locally adapted blood vessels
1,2 . The gain of such organotypic vessel specializations is often deemed to be molecularly unrelated to the process of organ vascularization. Here, opposing this model, we reveal a molecular mechanism for brain-specific angiogenesis that operates under the control of Wnt7a/b ligands-well-known blood-brain barrier maturation signals3-5 . The control mechanism relies on Wnt7a/b-dependent expression of Mmp25, which we find is enriched in brain endothelial cells. CRISPR-Cas9 mutagenesis in zebrafish reveals that this poorly characterized glycosylphosphatidylinositol-anchored matrix metalloproteinase is selectively required in endothelial tip cells to enable their initial migration across the pial basement membrane lining the brain surface. Mechanistically, Mmp25 confers brain invasive competence by cleaving meningeal fibroblast-derived collagen IV α5/6 chains within a short non-collagenous region of the central helical part of the heterotrimer. After genetic interference with the pial basement membrane composition, the Wnt-β-catenin-dependent organotypic control of brain angiogenesis is lost, resulting in properly patterned, yet blood-brain-barrier-defective cerebrovasculatures. We reveal an organ-specific angiogenesis mechanism, shed light on tip cell mechanistic angiodiversity and thereby illustrate how organs, by imposing local constraints on angiogenic tip cells, can select vessels matching their distinctive physiological requirements., (© 2024. The Author(s).)- Published
- 2024
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15. Border-zone cardiomyocytes and macrophages contribute to remodeling of the extracellular matrix to promote cardiomyocyte invasion during zebrafish cardiac regeneration.
- Author
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Constanty F, Wu B, Wei KH, Lin IT, Dallmann J, Guenther S, Lautenschlaeger T, Priya R, Lai SL, Stainier DYR, and Beisaw A
- Abstract
Despite numerous advances in our understanding of zebrafish cardiac regeneration, an aspect that remains less studied is how regenerating cardiomyocytes invade, and eventually replace, the collagen-containing fibrotic tissue following injury. Here, we provide an in-depth analysis of the process of cardiomyocyte invasion using live-imaging and histological approaches. We observed close interactions between protruding cardiomyocytes and macrophages at the wound border zone, and macrophage-deficient irf8 mutant zebrafish exhibited defects in extracellular matrix (ECM) remodeling and cardiomyocyte protrusion into the injured area. Using a resident macrophage ablation model, we show that defects in ECM remodeling at the border zone and subsequent cardiomyocyte protrusion can be partly attributed to a population of resident macrophages. Single-cell RNA-sequencing analysis of cells at the wound border revealed a population of cardiomyocytes and macrophages with fibroblast-like gene expression signatures, including the expression of genes encoding ECM structural proteins and ECM-remodeling proteins. The expression of mmp14b , which encodes a membrane-anchored matrix metalloproteinase, was restricted to cells in the border zone, including cardiomyocytes, macrophages, fibroblasts, and endocardial/endothelial cells. Genetic deletion of mmp14b led to a decrease in 1) macrophage recruitment to the border zone, 2) collagen degradation at the border zone, and 3) subsequent cardiomyocyte invasion. Furthermore, cardiomyocyte-specific overexpression of mmp14b was sufficient to enhance cardiomyocyte invasion into the injured tissue and along the apical surface of the wound. Altogether, our data shed important insights into the process of cardiomyocyte invasion of the collagen-containing injured tissue during cardiac regeneration. They further suggest that cardiomyocytes and resident macrophages contribute to ECM remodeling at the border zone to promote cardiomyocyte replenishment of the fibrotic injured tissue.
- Published
- 2024
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16. The potential of Ethiopian medicinal plants to treat emergent viral diseases.
- Author
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Fekadu M, Lulekal E, Tesfaye S, Ruelle M, Asfaw N, Awas T, Balemie K, Asres K, Guenther S, Asfaw Z, and Demissew S
- Subjects
- Animals, Humans, Antiviral Agents pharmacology, Antiviral Agents therapeutic use, Ethnobotany, Health Knowledge, Attitudes, Practice, Phytotherapy, Ethnopharmacology, Plants, Medicinal, Virus Diseases drug therapy
- Abstract
Ethiopians have deep-rooted traditions of using plants to treat ailments affecting humans and domesticated animals. Approximately 80% of the population continues to rely on traditional medicine, including for the prevention and treatment of viral diseases. Many antiviral plants are available to and widely used by communities in areas where access to conventional healthcare systems is limited. In some cases, pharmacological studies also confirm the potent antiviral properties of Ethiopian plants. Building on traditional knowledge of medicinal plants and testing their antiviral properties may help to expand options to address the global pandemic of COVID-19 including its recently isolated virulent variants and prepare for similar outbreaks in the future. Here, we provide an ethnobotanical and pharmacological inventory of Ethiopian medicinal plants that might contribute to the prevention and treatment of viral diseases. We identified 387 species, about 6% of Ethiopia's known flora, for which records of use by local communities and traditional herbalists have been documented for the treatment of viral diseases. We provide a framework for further investigation and development of this vital resource much anticipated to help combat emergent viral diseases along with existing ones in Ethiopia and elsewhere., (© 2023 The Authors. Phytotherapy Research published by John Wiley & Sons Ltd.)
- Published
- 2024
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17. The JAVELIN Bladder Medley trial: avelumab-based combinations as first-line maintenance in advanced urothelial carcinoma.
- Author
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Hoffman-Censits J, Grivas P, Powles T, Hawley J, Tyroller K, Seeberger S, Guenther S, Jacob N, Mehr KT, and Hahn NM
- Subjects
- Humans, Antibodies, Monoclonal adverse effects, Urinary Bladder, Multicenter Studies as Topic, Carcinoma, Transitional Cell drug therapy, Urinary Bladder Neoplasms drug therapy, Antibodies, Monoclonal, Humanized
- Abstract
Results from JAVELIN Bladder 100 established avelumab (anti-PD-L1) first-line maintenance as the standard-of-care treatment for patients with advanced urothelial carcinoma (UC) that has not progressed with first-line platinum-based chemotherapy. We describe the design of JAVELIN Bladder Medley (NCT05327530), an ongoing phase II, multicenter, randomized, open-label, parallel-arm, umbrella trial. Overall, 252 patients with advanced UC who are progression-free following first-line platinum-based chemotherapy will be randomized 1:2:2:2 to receive maintenance therapy with avelumab alone (control group) or combined with sacituzumab govitecan (anti-Trop-2/topoisomerase inhibitor conjugate), M6223 (anti-TIGIT) or NKTR-255 (recombinant human IL-15). Primary end points are progression-free survival per investigator and safety/tolerability of the combination regimens. Secondary end points include overall survival, objective response and duration of response per investigator, and pharmacokinetics.
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- 2024
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18. Quality parameters for the medicinal plant Drosera rotundifolia L.: A new approach with established techniques.
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Gerschler S, Neumann N, Schultze N, Guenther S, and Schulze C
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- Structure-Activity Relationship, Flavonoids, Plants, Medicinal, Drosera chemistry
- Abstract
Monographs of the European Pharmacopoeia (Ph. Eur.) are the basis for quality control of medicinal plants and therefore important to ensure the consistency, quality, safety, and efficacy of phytopharmaceuticals. The traditional medicinal plant sundew (Drosera sp.) has disappeared from therapy due to nature conservation, but can now be cultivated sustainably on rewetted peatland. However, currently there is no valid Ph. Eur. monograph for the quality control of Droserae herba. In this study, sundew material from different species and sources was investigated with the aim of developing quality control methods based on the Ph. Eur. and defining a uniform quality standard for Droserae herba. It was possible to distinguish between sundew species of different quality, using macroscopic, microscopic, and chromatographic methods. Special emphasis was laid on the content of flavonoids and naphthoquinones as important quality parameters as their content differed between the sundew species. The differences in content and toxicity result in the recommendation that only round-leaved sundew (Drosera rotundifolia L.) should be used as a medicinal plant for the production of phytopharmaceuticals in the future., (© 2023 The Authors. Archiv der Pharmazie published by Wiley-VCH GmbH on behalf of Deutsche Pharmazeutische Gesellschaft.)
- Published
- 2024
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19. Treatment patterns and clinical outcomes in metastatic urothelial carcinoma: a German retrospective real-world analysis.
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Niegisch G, Grimm MO, Hardtstock F, Krieger J, Starry A, Osowski U, Guenther S, Deiters B, Maywald U, Wilke T, and Kearney M
- Subjects
- Humans, Male, Female, Aged, Retrospective Studies, Germany epidemiology, Middle Aged, Treatment Outcome, Aged, 80 and over, Urologic Neoplasms mortality, Urologic Neoplasms pathology, Urologic Neoplasms drug therapy, Urologic Neoplasms therapy, Urinary Bladder Neoplasms mortality, Urinary Bladder Neoplasms pathology, Urinary Bladder Neoplasms therapy, Urinary Bladder Neoplasms drug therapy, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Neoplasm Metastasis, Carcinoma, Transitional Cell mortality, Carcinoma, Transitional Cell drug therapy, Carcinoma, Transitional Cell pathology, Carcinoma, Transitional Cell secondary, Carcinoma, Transitional Cell therapy
- Abstract
Aim: This study assessed real-world treatment in patients with metastatic urothelial carcinoma (mUC) in Germany. Materials & methods: Patients diagnosed with mUC from 2015 to 2019 were identified in two claims databases: AOK PLUS and GWQ. Results: 3226 patients with mUC were analyzed; 1286 (39.9%) received systemic treatment within 12 months of diagnosis (platinum-based chemotherapy: 64.2%). Factors associated with receiving treatment were: younger age, male sex, less comorbidity and recent diagnosis. In AOK PLUS and GWQ populations, unadjusted median overall survival (interquartile range) from diagnosis in treated patients was 13.7 (6.8-32.9) and 13.8 (7.1-41.7) months, and in untreated patients was 3.0 (1.2-10.8) and 3.6 (1.2-18.8) months, respectively. Conclusion: A significant proportion of patients with mUC in Germany receive no systemic treatment.
- Published
- 2024
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20. Single-Nucleus ATAC-seq for Mapping Chromatin Accessibility in Individual Cells of Murine Hearts.
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Yekelchyk M, Li X, Guenther S, and Braun T
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- Animals, Mice, Heart, Nucleosomes, Cell Nucleus genetics, Chromatin genetics, Chromatin Immunoprecipitation Sequencing
- Abstract
During the last decade a wide range of single-cell and single-nucleus next-generation sequencing techniques have been developed, which revolutionized detection of rare cell populations, enabling creation of comprehensive cell atlases of complex organs and tissues. State-of-the-art methods do not only allow classical transcriptomics of individual cells but also comprise a number of epigenetic approaches, including assessment of chromatin accessibility by single-nucleus Assay for Transposase Accessible Chromatin ATAC-seq (snATAC-seq). The snATAC-seq assay detects "open chromatin," a term for low nucleosome occupancy of genomic regions, which is a prerequisite for effective transcription factor binding. Information about open chromatin at the single-nucleus level helps to recognize epigenetic changes, sometimes before transcription of respective genes occurs. snATAC-seq detects cellular heterogeneity in otherwise still transcriptionally and/or morphologically homogeneous cell populations. Chromatin accessibility assays may be used to detect epigenetic changes in cardiac lineages during heart development, chromatin landscape changes during aging, and epigenetic alterations in heart diseases. Here, we provide an optimized protocol for snATAC-seq of murine hearts. We describe isolation of single nuclei from snap-frozen hearts, provide hints for preparation of libraries suitable for snATAC-seq next-generation sequencing (NGS) using the Chromium 10× platform, and give general recommendations for downstream analysis using conventional bioinformatic pipelines and packages. The protocol should serve as a beginner's guide to generate high-quality snATAC-seq datasets and to perform chromatin accessibility analysis of individual heart-derived cell nuclei., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)
- Published
- 2024
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21. Avelumab first-line maintenance treatment for advanced urothelial carcinoma: review of evidence to guide clinical practice.
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Grivas P, Grande E, Davis ID, Moon HH, Grimm MO, Gupta S, Barthélémy P, Thibault C, Guenther S, Hanson S, and Sternberg CN
- Subjects
- Humans, Cisplatin, Gemcitabine, Deoxycytidine, Carcinoma, Transitional Cell drug therapy, Urinary Bladder Neoplasms drug therapy
- Abstract
The JAVELIN Bladder 100 phase III trial led to the incorporation of avelumab first-line (1L) maintenance treatment into international guidelines as a standard of care for patients with advanced urothelial carcinoma (UC) without progression after 1L platinum-based chemotherapy. JAVELIN Bladder 100 showed that avelumab 1L maintenance significantly prolonged overall survival (OS) and progression-free survival in this population compared with a 'watch-and-wait' approach. The aim of this manuscript is to review clinical studies of avelumab 1L maintenance in patients with advanced UC, including long-term efficacy and safety data from JAVELIN Bladder 100, subgroup analyses in clinically relevant subpopulations, and 'real-world' data obtained outside of clinical trials, providing a comprehensive resource to support patient management. Extended follow-up from JAVELIN Bladder 100 has shown that avelumab provides a long-term efficacy benefit, with a median OS of 23.8 months measured from start of maintenance treatment, and 29.7 months measured from start of 1L chemotherapy. Longer OS was observed across subgroups, including patients who received 1L cisplatin + gemcitabine, patients who received four or six cycles of 1L chemotherapy, and patients with complete response, partial response, or stable disease as best response to 1L induction chemotherapy. No new safety signals were seen in patients who received ≥1 year of avelumab treatment, and toxicity was similar in those who had received cisplatin or carboplatin with gemcitabine. Other clinical datasets, including noninterventional studies conducted in Europe, USA, and Asia, have confirmed the efficacy of avelumab 1L maintenance. Potential subsequent treatment options after avelumab maintenance include antibody-drug conjugates (enfortumab vedotin or sacituzumab govitecan), erdafitinib in biomarker-selected patients, platinum rechallenge in suitable patients, nonplatinum chemotherapy, and clinical trial participation; however, evidence to determine optimal treatment sequences is needed. Ongoing trials of avelumab-based combination regimens as maintenance treatment have the potential to evolve the treatment landscape for patients with advanced UC., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
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22. Convergent Klebsiella pneumoniae strains belonging to a sequence type 307 outbreak clone combine cefiderocol and carbapenem resistance with hypervirulence.
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Schaufler K, Echelmeyer T, Schwabe M, Guenther S, Bohnert JA, Becker K, Fickenscher H, Bueter A, Maschkowitz G, Krumbholz A, Nurjadi D, Heiden SE, and Eger E
- Subjects
- Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Carbapenems pharmacology, Disease Outbreaks, beta-Lactamases genetics, Multilocus Sequence Typing, Cefiderocol, Klebsiella pneumoniae genetics, Cephalosporins
- Published
- 2023
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23. Antibiotic prophylaxis and hospitalization of horses subjected to median laparotomy: gut microbiota trajectories and abundance increase of Escherichia .
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Kauter A, Brombach J, Lübke-Becker A, Kannapin D, Bang C, Franzenburg S, Stoeckle SD, Mellmann A, Scherff N, Köck R, Guenther S, Wieler LH, Gehlen H, Semmler T, Wolf SA, and Walther B
- Abstract
Introduction: Horse clinics are hotspots for the accumulation and spread of clinically relevant and zoonotic multidrug-resistant bacteria, including extended-spectrum β-lactamase producing (ESBL) Enterobacterales. Although median laparotomy in cases of acute equine colic is a frequently performed surgical intervention, knowledge about the effects of peri-operative antibiotic prophylaxis (PAP) based on a combination of penicillin and gentamicin on the gut microbiota is limited., Methods: We collected fecal samples of horses from a non-hospitalized control group (CG) and from horses receiving either a pre-surgical single-shot (SSG) or a peri-operative 5-day (5DG) course of PAP. To assess differences between the two PAP regimens and the CG, all samples obtained at hospital admission (t
0 ), on days three (t1 ) and 10 (t2 ) after surgery, were screened for ESBL-producing Enterobacterales and subjected to 16S rRNA V1-V2 gene sequencing., Results: We included 48 samples in the SSG ( n = 16 horses), 45 in the 5DG ( n = 15), and 20 in the CG (for t0 and t1 , n = 10). Two samples of equine patients receiving antibiotic prophylaxis (6.5%) were positive for ESBL-producing Enterobacterales at t0 , while this rate increased to 67% at t1 and decreased only slightly at t2 (61%). Shannon diversity index (SDI) was used to evaluate alpha-diversity changes, revealing there was no significant difference between horses suffering from acute colic (5DG, SDImean of 5.90, SSG, SDImean of 6.17) when compared to the CG (SDImean of 6.53) at t0 . Alpha-diversity decreased significantly in both PAP groups at t1 , while at t2 the onset of microbiome recovery was noticed. Although we did not identify a significant SDImean difference with respect to PAP duration, the community structure (beta-diversity) was considerably restricted in samples of the 5DG at t1 , most likely due to the ongoing administration of antibiotics. An increased abundance of Enterobacteriaceae, especially Escherichia , was noted for both study groups at t1 ., Conclusion: Colic surgery and PAP drive the equine gut microbiome towards dysbiosis and reduced biodiversity that is accompanied by an increase of samples positive for ESBL-producing Enterobacterales. Further studies are needed to reveal important factors promoting the increase and residency of ESBL-producing Enterobacterales among hospitalized horses., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Kauter, Brombach, Lübke-Becker, Kannapin, Bang, Franzenburg, Stoeckle, Mellmann, Scherff, Köck, Guenther, Wieler, Gehlen, Semmler, Wolf and Walther.)- Published
- 2023
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24. Disrupted Binding of Cystathionine γ-Lyase to p53 Promotes Endothelial Senescence.
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Hu J, Leisegang MS, Looso M, Drekolia MK, Wittig J, Mettner J, Karantanou C, Kyselova A, Dumbovic G, Li X, Li Y, Guenther S, John D, Siragusa M, Zukunft S, Oo JA, Wittig I, Hille S, Weigert A, Knapp S, Brandes RP, Müller OJ, Papapetropoulos A, Sigala F, Dobreva G, Kojonazarov B, Fleming I, and Bibli SI
- Subjects
- Animals, Humans, Mice, Cellular Senescence, Cystathionine gamma-Lyase genetics, Cystathionine gamma-Lyase metabolism, Endothelial Cells metabolism, Tumor Suppressor Protein p53 genetics, Tumor Suppressor Protein p53 metabolism, Hydrogen Sulfide metabolism, Telomerase genetics, Telomerase metabolism
- Abstract
Background: Advanced age is unequivocally linked to the development of cardiovascular disease; however, the mechanisms resulting in reduced endothelial cell regeneration remain poorly understood. Here, we investigated novel mechanisms involved in endothelial cell senescence that impact endothelial cell transcription and vascular repair after injury., Methods: Native endothelial cells were isolated from young (20±3.4 years) and aged (80±2.3 years) individuals and subjected to molecular analyses to assess global transcriptional and metabolic changes. In vitro studies were conducted using primary human and murine endothelial cells. A murine aortic re-endothelialization model was used to examine endothelial cell regenerative capacity in vivo., Results: RNA sequencing of native endothelial cells revealed that aging resulted in p53-mediated reprogramming to express senescence-associated genes and suppress glycolysis. Reduced glucose uptake and ATP contributed to attenuated assembly of the telomerase complex, which was required for endothelial cell proliferation. Enhanced p53 activity in aging was linked to its acetylation on K120 due to enhanced activity of the acetyltransferase MOZ (monocytic leukemic zinc finger). Mechanistically, p53 acetylation and translocation were, at least partially, attributed to the loss of the vasoprotective enzyme, CSE (cystathionine γ-lyase). CSE physically anchored p53 in the cytosol to prevent its nuclear translocation and CSE absence inhibited AKT (Protein kinase B)-mediated MOZ phosphorylation, which in turn increased MOZ activity and subsequently p53 acetylation. In mice, the endothelial cell-specific deletion of CSE activated p53, induced premature endothelial senescence, and arrested vascular repair after injury. In contrast, the adeno-associated virus 9-mediated re-expression of an active CSE mutant retained p53 in the cytosol, maintained endothelial glucose metabolism and proliferation, and prevented endothelial cell senescence. Adenoviral overexpression of CSE in native endothelial cells from aged individuals maintained low p53 activity and reactivated telomerase to revert endothelial cell senescence., Conclusions: Aging-associated impairment of vascular repair is partly determined by the vasoprotective enzyme CSE., Competing Interests: Disclosures None.
- Published
- 2023
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25. Time-resolved Small-RNA Sequencing Identifies MicroRNAs Critical for Formation of Embryonic Stem Cells from the Inner Cell Mass of Mouse Embryos.
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Moradi S, Guenther S, Soori S, Sharifi-Zarchi A, Kuenne C, Khoddami V, Tavakol P, Kreutzer S, Braun T, and Baharvand H
- Abstract
Cells of the inner cell mass (ICM) acquire a unique ability for unlimited self-renewal during transition into embryonic stem cells (ESCs) in vitro, while preserving their natural multi-lineage differentiation potential. Several different pathways have been identified to play roles in ESC formation but the function of non-coding RNAs in this process is poorly understood. Here, we describe several microRNAs (miRNAs) that are crucial for efficient generation of mouse ESCs from ICMs. Using small-RNA sequencing, we characterize dynamic changes in miRNA expression profiles during outgrowth of ICMs in a high-resolution, time-course dependent manner. We report several waves of miRNA transcription during ESC formation, to which miRNAs from the imprinted Dlk1-Dio3 locus contribute extensively. In silico analyses followed by functional investigations reveal that Dlk1-Dio3 locus-embedded miRNAs (miR-541-5p, miR-410-3p, and miR-381-3p), miR-183-5p, and miR-302b-3p promote, while miR-212-5p and let-7d-3p inhibit ESC formation. Collectively, these findings offer new mechanistic insights into the role of miRNAs during ESC derivation., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
- Published
- 2023
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26. Natural phenolic compounds as biofilm inhibitors of multidrug-resistant Escherichia coli - the role of similar biological processes despite structural diversity.
- Author
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Buchmann D, Schwabe M, Weiss R, Kuss AW, Schaufler K, Schlüter R, Rödiger S, Guenther S, and Schultze N
- Abstract
Multidrug-resistant gram-negative pathogens such as Escherichia coli have become increasingly difficult to treat and therefore alternative treatment options are needed. Targeting virulence factors like biofilm formation could be one such option. Inhibition of biofilm-related structures like curli and cellulose formation in E. coli has been shown for different phenolic natural compounds like epigallocatechin gallate. This study demonstrates this effect for other structurally unrelated phenolics, namely octyl gallate, scutellarein and wedelolactone. To verify whether these structurally different compounds influence identical pathways of biofilm formation in E. coli a broad comparative RNA-sequencing approach was chosen with additional RT-qPCR to gain initial insights into the pathways affected at the transcriptomic level. Bioinformatical analysis of the RNA-Seq data was performed using DESeq2, BioCyc and KEGG Mapper. The comparative bioinformatics analysis on the pathways revealed that, irrespective of their structure, all compounds mainly influenced similar biological processes. These pathways included bacterial motility, chemotaxis, biofilm formation as well as metabolic processes like arginine biosynthesis and tricarboxylic acid cycle. Overall, this work provides the first insights into the potential mechanisms of action of novel phenolic biofilm inhibitors and highlights the complex regulatory processes of biofilm formation in E. coli ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Buchmann, Schwabe, Weiss, Kuss, Schaufler, Schlüter, Rödiger, Guenther and Schultze.)
- Published
- 2023
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27. Circular RNA circPLOD2 regulates pericyte function by targeting the transcription factor KLF4.
- Author
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Glaser SF, Brezski A, Baumgarten N, Klangwart M, Heumüller AW, Maji RK, Leisegang MS, Guenther S, Zehendner CM, John D, Schulz MH, Zarnack K, and Dimmeler S
- Subjects
- Humans, Hypoxia metabolism, Pericytes metabolism, RNA, Circular genetics, RNA, Circular metabolism
- Abstract
Circular RNAs are generated by backsplicing and control cellular signaling and phenotypes. Pericytes stabilize capillary structures and play important roles in the formation and maintenance of blood vessels. Here, we characterize hypoxia-regulated circular RNAs (circRNAs) in human pericytes and show that the circular RNA of procollagen-lysine,2-oxoglutarate 5-dioxygenase-2 (circPLOD2) is induced by hypoxia and regulates pericyte functions. Silencing of circPLOD2 affects pericytes and increases proliferation, migration, and secretion of soluble angiogenic proteins, thereby enhancing endothelial migration and network capability. Transcriptional and epigenomic profiling of circPLOD2-depleted cells reveals widespread changes in gene expression and identifies the transcription factor krüppel-like factor 4 (KLF4) as a key effector of the circPLOD2-mediated changes. KLF4 depletion mimics circPLOD2 silencing, whereas KLF4 overexpression reverses the effects of circPLOD2 depletion on proliferation and endothelial-pericyte interactions. Together, these data reveal an important function of circPLOD2 in controlling pericyte proliferation and capillary formation and show that the circPLOD2-mediated regulation of KLF4 significantly contributes to the transcriptional response to hypoxia., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
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28. Targeting Wnt-ß-Catenin-FOSL Signaling Ameliorates Right Ventricular Remodeling.
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Nayakanti SR, Friedrich A, Sarode P, Jafari L, Maroli G, Boehm M, Bourgeois A, Grobs Y, Khassafi F, Kuenne C, Guenther S, Dabral S, Wilhelm J, Weiss A, Wietelmann A, Kojonazarov B, Janssen W, Looso M, de Man F, Provencher S, Tello K, Seeger W, Bonnet S, Savai R, Schermuly RT, and Pullamsetti SS
- Subjects
- Rats, Mice, Animals, Ventricular Remodeling, beta Catenin, Catenins, Monocrotaline toxicity, Signal Transduction, Disease Models, Animal, Ventricular Function, Right, Pulmonary Arterial Hypertension, Heart Failure
- Abstract
Background: The ability of the right ventricle (RV) to adapt to an increased pressure afterload determines survival in patients with pulmonary arterial hypertension. At present, there are no specific treatments available to prevent RV failure, except for heart/lung transplantation. The wingless/int-1 (Wnt) signaling pathway plays an important role in the development of the RV and may also be implicated in adult cardiac remodeling., Methods: Molecular, biochemical, and pharmacological approaches were used both in vitro and in vivo to investigate the role of Wnt signaling in RV remodeling., Results: Wnt/β-catenin signaling molecules are upregulated in RV of patients with pulmonary arterial hypertension and animal models of RV overload (pulmonary artery banding-induced and monocrotaline rat models). Activation of Wnt/β-catenin signaling leads to RV remodeling via transcriptional activation of FOSL1 and FOSL2 (FOS proto-oncogene [FOS] like 1/2, AP-1 [activator protein 1] transcription factor subunit). Immunohistochemical analysis of pulmonary artery banding -exposed BAT-Gal (β-catenin-activated transgene driving expression of nuclear β-galactosidase) reporter mice RVs exhibited an increase in β-catenin expression compared with their respective controls. Genetic inhibition of β-catenin, FOSL1/2, or WNT3A stimulation of RV fibroblasts significantly reduced collagen synthesis and other remodeling genes. Importantly, pharmacological inhibition of Wnt signaling using inhibitor of PORCN (porcupine O-acyltransferase), LGKK-974 attenuated fibrosis and cardiac hypertrophy leading to improvement in RV function in both, pulmonary artery banding - and monocrotaline-induced RV overload., Conclusions: Wnt- β-Catenin-FOSL signaling is centrally involved in the hypertrophic RV response to increased afterload, offering novel targets for therapeutic interference with RV failure in pulmonary hypertension., Competing Interests: Disclosures None.
- Published
- 2023
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29. The RNA editor ADAR2 promotes immune cell trafficking by enhancing endothelial responses to interleukin-6 during sterile inflammation.
- Author
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Gatsiou A, Tual-Chalot S, Napoli M, Ortega-Gomez A, Regen T, Badolia R, Cesarini V, Garcia-Gonzalez C, Chevre R, Ciliberti G, Silvestre-Roig C, Martini M, Hoffmann J, Hamouche R, Visker JR, Diakos N, Wietelmann A, Silvestris DA, Georgiopoulos G, Moshfegh A, Schneider A, Chen W, Guenther S, Backs J, Kwak S, Selzman CH, Stamatelopoulos K, Rose-John S, Trautwein C, Spyridopoulos I, Braun T, Waisman A, Gallo A, Drakos SG, Dimmeler S, Sperandio M, Soehnlein O, and Stellos K
- Subjects
- Endothelial Cells metabolism, Cytokine Receptor gp130, Endothelium metabolism, Adenosine Deaminase genetics, Adenosine Deaminase metabolism, RNA, Interleukin-6
- Abstract
Immune cell trafficking constitutes a fundamental component of immunological response to tissue injury, but the contribution of intrinsic RNA nucleotide modifications to this response remains elusive. We report that RNA editor ADAR2 exerts a tissue- and stress-specific regulation of endothelial responses to interleukin-6 (IL-6), which tightly controls leukocyte trafficking in IL-6-inflamed and ischemic tissues. Genetic ablation of ADAR2 from vascular endothelial cells diminished myeloid cell rolling and adhesion on vascular walls and reduced immune cell infiltration within ischemic tissues. ADAR2 was required in the endothelium for the expression of the IL-6 receptor subunit, IL-6 signal transducer (IL6ST; gp130), and subsequently, for IL-6 trans-signaling responses. ADAR2-induced adenosine-to-inosine RNA editing suppressed the Drosha-dependent primary microRNA processing, thereby overwriting the default endothelial transcriptional program to safeguard gp130 expression. This work demonstrates a role for ADAR2 epitranscriptional activity as a checkpoint in IL-6 trans-signaling and immune cell trafficking to sites of tissue injury., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
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30. The developing epicardium regulates cardiac chamber morphogenesis by promoting cardiomyocyte growth.
- Author
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Boezio GLM, Zhao S, Gollin J, Priya R, Mansingh S, Guenther S, Fukuda N, Gunawan F, and Stainier DYR
- Subjects
- Animals, Ligands, Vascular Endothelial Growth Factor A metabolism, Pericardium metabolism, Organogenesis genetics, Heart physiology, Myocardium metabolism, Transcription Factors genetics, Transcription Factors metabolism, WT1 Proteins genetics, WT1 Proteins metabolism, Zebrafish Proteins genetics, Zebrafish Proteins metabolism, Zebrafish metabolism, Myocytes, Cardiac metabolism
- Abstract
The epicardium, the outermost layer of the heart, is an important regulator of cardiac regeneration. However, a detailed understanding of the crosstalk between the epicardium and myocardium during development requires further investigation. Here, we generated three models of epicardial impairment in zebrafish by mutating the transcription factor genes tcf21 and wt1a, and ablating tcf21+ epicardial cells. Notably, all three epicardial impairment models exhibited smaller ventricles. We identified the initial cause of this phenotype as defective cardiomyocyte growth, resulting in reduced cell surface and volume. This failure of cardiomyocyte growth was followed by decreased proliferation and increased abluminal extrusion. By temporally manipulating its ablation, we show that the epicardium is required to support cardiomyocyte growth mainly during early cardiac morphogenesis. By transcriptomic profiling of sorted epicardial cells, we identified reduced expression of FGF and VEGF ligand genes in tcf21-/- hearts, and pharmacological inhibition of these signaling pathways in wild type partially recapitulated the ventricular growth defects. Taken together, these data reveal distinct roles of the epicardium during cardiac morphogenesis and signaling pathways underlying epicardial-myocardial crosstalk., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2022. Published by The Company of Biologists Ltd.)
- Published
- 2023
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31. Improved efficacy of eugenol and trans -anethole in combination with octenidine dihydrochloride against Candida albicans and Candida parapsilosis .
- Author
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Dąbrowska M, Zielińska-Bliźniewska H, Kwiatkowski P, Guenther S, Łopusiewicz Ł, Kochan E, Pruss A, and Sienkiewicz M
- Subjects
- Humans, Candida albicans, Candida parapsilosis, Eugenol pharmacology, Candida, Microbial Sensitivity Tests, Antifungal Agents pharmacology, Candidiasis drug therapy, Candidiasis microbiology
- Abstract
Introduction and Objective: Candidiasis is a fungal infection caused by yeasts from the Ogenus Candida. Considering increasing antifungal resistance rates the activity was analyzed of natural compounds to eradicate Candida spp. The aim of the study was to check the antifungal activity of selected essential oil compounds (EOCs; thymol, menthol, eugenol [E], carvacrol, trans-anethole [TA]) alone, and in combination with octenidine dihydrochloride (OCT) against C. albicans and C. parapsilosis reference, and clinical strains., Material and Methods: Investigated clinical isolates were obtained from skin wounds of patients treated for superficial wounds candidiasis. The following parameters were studied: antifungal susceptibility testing using the VITEK system, antifungal activity of EOCs alone and in combination with OCT using microdilution and checkerboard assays, antifungal efficacy of selected chemicals using time-kill curve assay, and changes in cell permeability in the presence of selected chemicals using crystal violet assay., Results: Clinical isolates of C. albicans and C. parapsilosis were resistant to fluconazole and voriconazole. The highest inhibition activity against Candida isolates was observed for E. The OCT - TA and OCT - E combinations showed synergistic and additive activities against all strains, respectively. These combinations also appeared to affect the rate of yeast cell killing and increasing the permeability of Candida cells., Conclusions: The study indicates that E and TA potentially used in formulation with OCT might eradicate pathogenic yeasts; however, microbiological and clinical studies are still required.
- Published
- 2023
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32. Assessment of the Anticancer Effect of Chlorojanerin Isolated from Centaurothamnus maximus on A549 Lung Cancer Cells.
- Author
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Noman O, Nasr FA, Ahmed MZ, Rehman MT, Qamar W, Alqahtani AS, and Guenther S
- Subjects
- Humans, A549 Cells, Molecular Docking Simulation, Cell Line, Tumor, Cell Cycle Checkpoints, Cell Proliferation, Apoptosis, Proto-Oncogene Proteins c-bcl-2 genetics, Lung Neoplasms drug therapy, Lung Neoplasms metabolism
- Abstract
The goal of this study was to assess the anticancer efficacy of chlorojanerin against various cancer cells. The effects of chlorojanerin on cell cytotoxicity, cell cycle arrest, and cell apoptosis were examined using MTT assay, propidium iodide staining, and FITC Annexin V assay. RT-PCR was employed to determine the expression levels of apoptosis-related genes. Furthermore, docking simulations were utilized to further elucidate the binding preferences of chlorojanerin with Bcl-2. According to MTT assay, chlorojanerin inhibited the proliferation of all tested cells in a dose-dependent manner with a promising effect against A549 lung cancer cells with an IC
50 of 10 µM. Cell growth inhibition by chlorojanerin was linked with G2/M phase cell cycle arrest in A549 treated cells. Flow cytometry analysis indicated that the proliferation inhibition effect of chlorojanerin was associated with apoptosis induction in A549 cells. Remarkably, chlorojanerin altered the expression of many genes involved in apoptosis initiation. Moreover, we determined that chlorojanerin fit into the active site of Bcl-2 according to the molecular docking study. Collectively, our results demonstrate that chlorojanerin mediated an anticancer effect involving cell cycle arrest and apoptotic cell death and, therefore, could potentially serve as a therapeutic agent in lung cancer treatment., Competing Interests: The authors declare no conflict of interest.- Published
- 2023
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33. Genomic analysis of the international high-risk clonal lineage Klebsiella pneumoniae sequence type 395.
- Author
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Shaidullina ER, Schwabe M, Rohde T, Shapovalova VV, Dyachkova MS, Matsvay AD, Savochkina YA, Shelenkov AA, Mikhaylova YV, Sydow K, Lebreton F, Idelevich EA, Heiden SE, Becker K, Kozlov RS, Shipulin GA, Akimkin VG, Lalk M, Guenther S, Zautner AE, Bohnert JA, Mardanova AM, Bouganim R, Marchaim D, Hoff KJ, Schaufler K, and Edelstein MV
- Subjects
- Humans, Anti-Bacterial Agents, Carbapenems, Genomics, Plasmids, Clone Cells, beta-Lactamases genetics, Klebsiella pneumoniae genetics, Genes, Bacterial, Drug Resistance, Bacterial genetics
- Abstract
Background: Klebsiella pneumoniae, which is frequently associated with hospital- and community-acquired infections, contains multidrug-resistant (MDR), hypervirulent (hv), non-MDR/non-hv as well as convergent representatives. It is known that mostly international high-risk clonal lineages including sequence types (ST) 11, 147, 258, and 307 drive their global spread. ST395, which was first reported in the context of a carbapenemase-associated outbreak in France in 2010, is a less well-characterized, yet emerging clonal lineage., Methods: We computationally analyzed a large collection of K. pneumoniae ST395 genomes (n = 297) both sequenced in this study and reported previously. By applying multiple bioinformatics tools, we investigated the core-genome phylogeny and evolution of ST395 as well as distribution of accessory genome elements associated with antibiotic resistance and virulence features., Results: Clustering of the core-SNP alignment revealed four major clades with eight smaller subclades. The subclades likely evolved through large chromosomal recombination, which involved different K. pneumoniae donors and affected, inter alia, capsule and lipopolysaccharide antigen biosynthesis regions. Most genomes contained acquired resistance genes to extended-spectrum cephalosporins, carbapenems, and other antibiotic classes carried by multiple plasmid types, and many were positive for hypervirulence markers, including the siderophore aerobactin. The detection of "hybrid" resistance and virulence plasmids suggests the occurrence of the convergent ST395 pathotype., Conclusions: To the best of our knowledge, this is the first study that investigated a large international collection of K. pneumoniae ST395 genomes and elucidated phylogenetics and detailed genomic characteristics of this emerging high-risk clonal lineage., (© 2023. The Author(s).)
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- 2023
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34. Carriage of Extended Spectrum Beta Lactamase-Producing Escherichia coli : Prevalence and Factors Associated with Fecal Colonization of Dogs from a Pet Clinic in Lower Saxony, Germany.
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Werhahn Beining M, Hartmann M, Luebke-Becker A, Guenther S, Schaufler K, Hille K, and Kreienbrock L
- Abstract
Extended spectrum beta-lactamase (ESBL)-producing Escherichia coli are an emerging problem in veterinary and human medicine. Our study concentrated on the estimation of the prevalence and factors associated with the carriage of ESBL-producing E. coli in dogs who visited a veterinary clinic in northern Germany in 2017. For this reason, 1000 patients (healthy and sick dogs) were tested, resulting in 1000 samples originating from rectal swabs. Additional data were collected using a self-reported questionnaire that was completed by the dog owner. Factors associated with ESBL carriage were considered for further modeling if p < 0.05 using a two-sided Fisher test. Using a backward elimination procedure, the variables for the final multivariable logistic regression model were identified. In total, 8.9% of the dogs tested were positive for carriage of ESBL-producing E. coli . Seven factors were associated with the colonization of dogs with ESBL- E. coli within the multivariable model, namely husbandry system ( p = 0.0019, OR = 3.00; 95% CI: 1.50-6.00), contact with puppies ( p = 0.0044, OR = 2.43; 95% CI: 1.32-4.46), feeding of raw meat ( p = 0.011, OR = 2.28; 95% CI: 1.21-4.31), food residues ( p = 0.0151, OR = 2.31; 95% CI: 1.18-4.53) and food supplements ( p = 0.0487, OR = 0.426; 95% CI: 0.18-0.96), and antibiotic treatments of dogs ( p = 0.0005, OR = 3.030; 95% CI: 1.62-5.68) or owners ( p = 0.041, OR = 2.74; 95% CI: 1.04-7.19) prior to the study. These factors refer to the animals themselves as well as to the owners and their habits or medical treatments. Although the causality and direction of transmission from owners to their dogs cannot be proven, the factor of antibiotic treatment of the owner is clearly associated with the dog's status.
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- 2023
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35. Assay for Transposase-Accessible Chromatin Using Sequencing of Freshly Isolated Muscle Stem Cells.
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Yekelchyk M, Guenther S, and Braun T
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- Animals, Mice, Chromatin Immunoprecipitation Sequencing, Transposases metabolism, High-Throughput Nucleotide Sequencing methods, Sequence Analysis, DNA methods, Stem Cells metabolism, Muscles metabolism, Chromatin genetics, Nucleosomes
- Abstract
Actively transcribed genes harbor cis-regulatory modules with comparatively low nucleosome occupancy and few high-order structures (="open chromatin"), whereas non-transcribed genes are characterized by high nucleosome density and extensive interactions between nucleosomes (="closed chromatin"), preventing transcription factor binding. Knowledge about chromatin accessibility is crucial to understand gene regulatory networks determining cellular decisions. Several techniques are available to map chromatin accessibility, among which the Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) is one of the most popular. ATAC-seq is based on a straightforward and robust protocol but requires adjustments for different cell types. Here, we describe an optimized protocol for ATAC-seq of freshly isolated murine muscle stem cells. We provide details for the isolation of MuSC, tagmentation, library amplification, double-sided SPRI bead cleanup, and library quality assessment and give recommendations for sequencing parameters and downstream analysis. The protocol should facilitate generation of high-quality data sets of chromatin accessibility in MuSCs, even for newcomers to the field., (© 2023. Springer Science+Business Media, LLC, part of Springer Nature.)
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- 2023
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36. The regional distribution of resident immune cells shapes distinct immunological environments along the murine epididymis.
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Pleuger C, Ai D, Hoppe ML, Winter LT, Bohnert D, Karl D, Guenther S, Epelman S, Kantores C, Fijak M, Ravens S, Middendorff R, Mayer JU, Loveland KL, Hedger M, Bhushan S, and Meinhardt A
- Subjects
- Mice, Male, Animals, Sperm Maturation, Spermatozoa, Testis, Epididymis, Semen
- Abstract
The epididymis functions as transition zone for post-testicular sperm maturation and storage and faces contrasting immunological challenges, i.e. tolerance towards spermatozoa vs. reactivity against pathogens. Thus, normal organ function and integrity relies heavily on a tightly controlled immune balance. Previous studies described inflammation-associated tissue damage solely in the distal regions (corpus, cauda), but not in the proximal regions (initial segment, caput). To understand the observed region-specific immunity along the epididymal duct, we have used an acute bacterial epididymitis mouse model and analyzed the disease progression. Whole transcriptome analysis using RNAseq 10 days post infection showed a pro-inflammatory environment within the cauda, while the caput exhibited only minor transcriptional changes. High-dimensional flow cytometry analyses revealed drastic changes in the immune cell composition upon infection with uropathogenic Escherichia coli . A massive influx of neutrophils and monocytes was observed exclusively in distal regions and was associated with bacterial appearance and tissue alterations. In order to clarify the reasons for the region-specific differences in the intensity of immune responses, we investigated the heterogeneity of resident immune cell populations under physiological conditions by scRNASeq analysis of extravascular CD45+ cells. Twelve distinct immune cell subsets were identified, displaying substantial differences in distribution along the epididymis as further assessed by flow cytometry and immunofluorescence staining. Macrophages constituted the majority of resident immune cells and were further separated in distinct subgroups based on their transcriptional profile, tissue location and monocyte-dependence. Crucially, the proximal and distal regions showed striking differences in their immunological landscapes. These findings indicate that resident immune cells are strategically positioned along the epididymal duct, potentially providing different immunological environments required for addressing the contrasting immunological challenges and thus, preserving tissue integrity and organ function., Competing Interests: CP, DA, MH, LW, DB, DK, SG, SE, CK, MF, SR, RM, JM, KL, MH, SB, AM No competing interests declared, (© 2022, Pleuger et al.)
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- 2022
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37. Anti-malarial effect of a combination of risedronate and azithromycin against Plasmodium yoelii nigeriensis infection in Swiss mice.
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Tesfaye S, Asres K, Guenther S, and Singh PP
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- Animals, Azithromycin pharmacology, Azithromycin therapeutic use, Mice, Risedronic Acid pharmacology, Risedronic Acid therapeutic use, Antimalarials pharmacology, Antimalarials therapeutic use, Malaria parasitology, Plasmodium yoelii
- Abstract
Combination therapy is used to retard the selection of malaria parasite strains resistant to individual components of a combination of drugs. This approach has proved to be a success in the combination of sulphadoxine and pyrimethamine, which targets two different steps in the folate pathway of malaria parasites. However, after the success of this therapeutic combination, the efficacy of other combinations of drugs that target different enzymes in a particular metabolic pathway has, apparently, not been reported. In the current study, the antimalarial effect of a combination of risedronate (RIS), which is known for its anti-osteoporosis activity, and azithromycin (AZT) was investigated. Peter's suppression test was carried out on mice infected with 1 × 10
7 P. yoelii infected erythrocytes. Drug efficacy was analyzed by comparing the percent reduction in parasitaemia on day 4 post-infection. RIS was observed to be a blood schizonticidal agent against P. yoelii infection which showed ED50 7.0 (4.04-12.13) mg/kg/day x 4. Normalized isobologram showed additive action between RIS 1 mg/kg/day x 4 and AZT 10 mg/kg/day x 4, and antagonistic action for the rest of the combinations (RIS 1 + AZT 20, RIS 1 + AZT 40, RIS 5 + AZT 10, RIS 5 + AZT 20, RIS 5 + AZT 40, RIS 10 + AZT 10, RIS 10 + AZT 20 and RIS 10 + AZT 40 mg/kg/day x 4). Furthermore, a combination of RIS with AZT showed inferior efficacy as compared to AZT treatment alone. This antagonistic interaction may be due to the high accumulation of AZT in WBCs, which will reduce its serum bio-availability, whereas RIS has anti-parasitic activity by increasing WBCs., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2022 Elsevier B.V. All rights reserved.)- Published
- 2022
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38. Antibiofilm Activity of Sundew Species against Multidrug-Resistant Escherichia coli Strains.
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Gerschler S, Guenther S, and Schulze C
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- Flavonoids pharmacology, Escherichia coli, Plant Extracts pharmacology, Plant Extracts therapeutic use, Biofilms, Drosera
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Species of the genus Drosera , known for carnivorous plants, such as sundew, have been traditionally used for centuries as medicinal plants. Efficacy-determining compounds are naphthoquinones and flavonoids. Flavonoids possess a broad spectrum of bioactive properties, including biofilm inhibitory activity. Biofilms render antibiotics ineffective, contributing to the current rise in antimicrobial resistance. In this study, the biofilm inhibitory activity of two European sundew species ( Drosera rotundifolia and Drosera intermedia ) grown agriculturally in Germany and four commercial sundew products (declared as Drosera longifolia , Drosera sp. and Drosera planta trit.) against three multidrug-resistant Escherichia coli strains was tested. The aim of the study was to comparatively investigate the biofilm inhibitory potential of sundew species extracts grown locally in northern Germany and commercial sundew products. The minimum biofilm inhibitory concentration of the European sundew species was approx. 35 µg mL
-1 . In comparison, commercial sundew products ranged in concentration from 75 to 140 µg mL-1 . Additionally, individual compounds isolated from European sundew were tested. Among these compounds, biofilm inhibitory activity was determined for four of the eight substances, with 2″-O-galloyl hyperoside standing out for its activity (38 µg mL-1 ). The whole plant extracts of Drosera rotundifolia and Drosera intermedia proved to be more effective than the commercial products and the single compounds in its biofilm inhibition activity against Escherichia coli strains. Sundew extracts may serve as a potential therapeutic approach for targeting biofilm production.- Published
- 2022
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39. A Combined Bayesian and Similarity-Based Approach for Predicting E. coli Biofilm Inhibition by Phenolic Natural Compounds.
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Stepanov D, Buchmann D, Schultze N, Wolber G, Schaufler K, Guenther S, and Belik V
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- Bayes Theorem, Phenols pharmacology, Escherichia coli, Biofilms
- Abstract
Screening for biofilm inhibition by purified natural compounds is difficult due to compounds' chemical diversity and limited commercial availability, combined with time- and cost-intensiveness of the laboratory process. In silico prediction of chemical and biological properties of molecules is a widely used technique when experimental data availability is of concern. At the same time, the performance of predictive models directly depends on the amount and quality of experimental data. Driven by the interest in developing a model for prediction of the antibiofilm effect of phenolic natural compounds such as flavonoids, we performed experimental assessment of antibiofilm activity of 320 compounds from this subset of chemicals. The assay was performed once on two Escherichia coli strains on agar in 24-well microtiter plates. The inhibition was assessed visually by detecting morphological changes in macrocolonies. Using the data obtained, we subsequently trained a Bayesian logistic regression model for prediction of biofilm inhibition, which was combined with a similarity-based method in order to increase the overall sensitivity (at the cost of accuracy). The quality of the predictions was subsequently validated by experimental assessment in three independent experiments with two resistant E. coli strains of 23 compounds absent in the initial data set. The validation demonstrated that the model may successfully predict the targeted effect as compared to the baseline accuracy. Using a randomly selected database of commercially available natural phenolics, we obtained approximately 6.0% of active compounds, whereas using our prediction-based substance selection, the percentage of phenolics found to be active increased to 34.8%.
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- 2022
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40. Unravelling the impact of aging on the human endothelial lncRNA transcriptome.
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Drekolia MK, Talyan S, Cordellini Emídio R, Boon RA, Guenther S, Looso M, Dumbović G, and Bibli SI
- Abstract
The incidence and prevalence of cardiovascular disease is highest among the elderly. There is a need to further understand the mechanisms behind endothelial cell aging in order to achieve vascular rejuvenation and minimize the onset of age-related vascular diseases. Long non-coding RNAs (lncRNAs) have been proposed to regulate numerous processes in the human genome, yet their function in vascular aging and their therapeutic potential remain largely unknown. This is primarily because the majority of studies investigating the impact of aging on lncRNA expression heavily rely on in vitro studies based on replicative senescence. Here, using a unique collection of young and aged endothelial cells isolated from native human arteries, we sought to characterize the age-related alterations in lncRNA expression profiles. We were able to detect a total of 4463 lncRNAs expressed in the human endothelium from which ∼17% (798) were altered in advanced age. One of the most affected lncRNAs in aging was the primate-specific, Prostate Cancer Associated Transcript (PCAT) 14. In our follow up analysis, using single molecule RNA FISH, we showed that PCAT14 is relatively abundant, localized almost exclusively in the nucleus of young endothelial cells, and silenced in the aged endothelium. Functionally, our studies proposed that downregulation of PCAT14 alters endothelial cell transcription profile and cell functions including endothelial cell migration, sprouting and inflammatory responses in vitro . Taken together, our data highlight that endothelial cell aging correlates with altered expression of lncRNAs, which could impair the endothelial regenerative capacity and enhance inflammatory phenotypes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Drekolia, Talyan, Cordellini Emídio, Boon, Guenther, Looso, Dumbović and Bibli.)
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- 2022
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41. Multidrug-Resistant High-Risk Escherichia coli and Klebsiella pneumoniae Clonal Lineages Occur in Black-Headed Gulls from Two Conservation Islands in Germany.
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Brendecke J, Homeier-Bachmann T, Schmitz Ornés A, Guenther S, Heiden SE, Schwabe M, Eger E, and Schaufler K
- Abstract
Multidrug-resistant (MDR) Enterobacterales , including extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae , not only emerge in healthcare settings but also in other habitats, such as livestock and wildlife. The spread of these pathogens, which often combine resistance with high-level virulence, is a growing problem, as infections have become increasingly difficult to treat. Here, we investigated the occurrence of ESBL-producing E. coli and K. pneumoniae in fecal samples from two black-headed gull colonies breeding on two nature conservation islands in Western Pomerania, Germany. In addition to cloacal samples from adult birds ( n = 211) and their nestlings ( n = 99) during the 2021 breeding season, collective fecal samples ( n = 29) were obtained. All samples were screened for ESBL producers, which were then subjected to whole-genome sequencing. We found a total of 12 ESBL-producing E. coli and K. pneumoniae consisting of 11 E. coli and 1 K. pneumoniae , and including the international high-risk E. coli sequence types (ST)131, ST38, and ST58. Eight of the investigated strains had a MDR genotype and carried a large repertoire of virulence-associated genes, including the pap operon, which is important for urinary tract infections. In addition, we identified many genes associated with adherence, biofilm formation, iron uptake, and toxin production. Finally, our analysis revealed the close phylogenetic relationship of ST38 strains with genomes originating from human sources, underlining their zoonotic and pathogenic character. This study highlights the importance of the One Health approach, and thus the interdependence between human and animal health and their surrounding environment.
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- 2022
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42. Endothelial versus pronephron fate decision is modulated by the transcription factors Cloche/Npas4l, Tal1, and Lmo2.
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Mattonet K, Riemslagh FW, Guenther S, Prummel KD, Kesavan G, Hans S, Ebersberger I, Brand M, Burger A, Reischauer S, Mosimann C, and Stainier DYR
- Abstract
Endothelial specification is a key event during embryogenesis; however, when, and how, endothelial cells separate from other lineages is poorly understood. In zebrafish, Npas4l is indispensable for endothelial specification by inducing the expression of the transcription factor genes etsrp , tal1 , and lmo2 . We generated a knock-in reporter in zebrafish npas4l to visualize endothelial progenitors and their derivatives in wild-type and mutant embryos. Unexpectedly, we find that in npas4l mutants, npas4l reporter-expressing cells contribute to the pronephron tubules. Single-cell transcriptomics and live imaging of the early lateral plate mesoderm in wild-type embryos indeed reveals coexpression of endothelial and pronephron markers, a finding confirmed by creERT2-based lineage tracing. Increased contribution of npas4l reporter-expressing cells to pronephron tubules is also observed in tal1 and lmo2 mutants and is reversed in npas4l mutants injected with tal1 mRNA. Together, these data reveal that Npas4l/Tal1/Lmo2 regulate the fate decision between the endothelial and pronephron lineages.
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- 2022
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43. Microbial iron reduction compensates for phosphorus limitation in paddy soils.
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Wang C, Thielemann L, Dippold MA, Guggenberger G, Kuzyakov Y, Banfield CC, Ge T, Guenther S, Bork P, Horn MA, and Dorodnikov M
- Subjects
- Ferric Compounds metabolism, Iron analysis, Oxides, Phosphorus metabolism, Soil, Oryza, Soil Pollutants analysis
- Abstract
Limitation of rice growth by low phosphorus (P) availability is a widespread problem in tropical and subtropical soils because of the high content of iron (Fe) (oxyhydr)oxides. Ferric iron-bound P (Fe(III)-P) can serve as a P source in paddies after Fe(III) reduction to Fe(II) and corresponding H
2 PO4 - release. However, the relevance of reductive dissolution of Fe(III)-P for plant and microbial P uptake is still an open question. To quantify this,32 P-labeled ferrihydrite (30.8 mg P kg-1 ) was added to paddy soil mesocosms with rice to trace the P uptake by microorganisms and plants after Fe(III) reduction. Nearly 2% of32 P was recovered in rice plants, contributing 12% of the total P content in rice shoots and roots after 33 days. In contrast,32 P recovery in microbial biomass decreased from 0.5% to 0.08% of32 P between 10 and 33 days after rice transplantation. Microbial biomass carbon (MBC) and dissolved organic C content decreased from day 10 to 33 by 8-54% and 68-77%, respectively, suggesting that the microbial-mediated Fe(III) reduction was C-limited. The much faster decrease of MBC in rooted (by 54%) vs. bulk soil (8-36%) reflects very fast microbial turnover in the rice rhizosphere (high C and oxygen inputs) resulting in the mineralization of the microbial necromass. In conclusion, Fe(III)-P can serve as small but a relevant P source for rice production and could partly compensate plant P demand. Therefore, the P fertilization strategies should consider the P mobilization from Fe (oxyhydr)oxides in flooded paddy soils during rice growth. An increase in C availability for microorganisms in the rhizosphere intensifies P mobilization, which is especially critical at early stages of rice growth., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)- Published
- 2022
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44. Combined fibre atrophy and decreased muscle regeneration capacity driven by mitochondrial DNA alterations underlie the development of sarcopenia.
- Author
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Kimoloi S, Sen A, Guenther S, Braun T, Brügmann T, Sasse P, Wiesner RJ, Pla-Martín D, and Baris OR
- Subjects
- Animals, DNA, Mitochondrial genetics, DNA, Mitochondrial metabolism, Mice, Mitochondria metabolism, Muscle, Skeletal pathology, Regeneration, Sarcopenia pathology
- Abstract
Background: Mitochondrial dysfunction caused by mitochondrial (mtDNA) deletions have been associated with skeletal muscle atrophy and myofibre loss. However, whether such defects occurring in myofibres cause sarcopenia is unclear. Also, the contribution of mtDNA alterations in muscle stem cells (MuSCs) to sarcopenia remains to be investigated., Methods: We expressed a dominant-negative variant of the mitochondrial helicase, which induces mtDNA alterations, specifically in differentiated myofibres (K320E
skm mice) and MuSCs (K320Emsc mice), respectively, and investigated their impact on muscle structure and function by immunohistochemistry, analysis of mtDNA and respiratory chain content, muscle transcriptome and functional tests., Results: K320Eskm mice at 24 months of age had higher levels of mtDNA deletions compared with controls in soleus (SOL, 0.07673% vs. 0.00015%, P = 0.0167), extensor digitorum longus (EDL, 0.0649 vs. 0.000925, P = 0.0015) and gastrocnemius (GAS, 0.09353 vs. 0.000425, P = 0.0004). K320Eskm mice revealed a progressive increase in the proportion of cytochrome c oxidase deficient (COX- ) fibres in skeletal muscle cross sections, reaching a maximum of 3.03%, 4.36%, 13.58%, and 17.08% in EDL, SOL, tibialis anterior (TA) and GAS, respectively. However, mice did not show accelerated loss of muscle mass, muscle strength or physical performance. Histological analyses revealed ragged red fibres but also stimulated regeneration, indicating activation of MuSCs. RNAseq demonstrated enhanced expression of genes associated with protein synthesis, but also degradation, as well as muscle fibre differentiation and cell proliferation. In contrast, 7 days after destruction by cardiotoxin, regenerating TA of K320Emsc mice showed 30% of COX- fibres. Notably, regenerated muscle showed dystrophic changes, increased fibrosis (2.5% vs. 1.6%, P = 0.0003), increased abundance of fat cells (2.76% vs. 0.23%, P = 0.0144) and reduced muscle mass (regenerated TA: 40.0 mg vs. 60.2 mg, P = 0.0171). In contrast to muscles from K320Eskm mice, freshly isolated MuSCs from aged K320Emsc mice were completely devoid of mtDNA alterations. However, after passaging, mtDNA copy number as well as respiratory chain subunits and p62 levels gradually decreased., Conclusions: Taken together, accumulation of large-scale mtDNA alterations in myofibres alone is not sufficient to cause sarcopenia. Expression of K320E-Twinkle is tolerated in quiescent MuSCs, but progressively leads to mtDNA and respiratory chain depletion upon activation, in vivo and in vitro, possibly caused by an increased mitochondrial removal. Altogether, our results suggest that the accumulation of mtDNA alterations in myofibres activates regeneration during aging, which leads to sarcopenia if such alterations have expanded in MuSCs as well., (© 2022 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of Society on Sarcopenia, Cachexia and Wasting Disorders.)- Published
- 2022
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45. Oral, intranasal, and intravenous abuse potential of serdexmethylphenidate, a novel prodrug of d-methylphenidate.
- Author
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Shram MJ, Setnik B, Webster L, Guenther S, Mickle TC, Braeckman R, Kanski J, Martin A, Kelsh D, Vince BD, and Barrett AC
- Subjects
- Cross-Over Studies, Delayed-Action Preparations therapeutic use, Double-Blind Method, Humans, Phentermine, Treatment Outcome, Attention Deficit Disorder with Hyperactivity drug therapy, Central Nervous System Stimulants adverse effects, Methylphenidate adverse effects, Prodrugs adverse effects, Substance Abuse, Intravenous
- Abstract
Objectives: Serdexmethylphenidate (SDX) chloride (Cl) is a novel prodrug of d-methylphenidate (d-MPH). These studies evaluated the abuse potential of SDX Cl when administered orally, intranasally (IN), and intravenously (IV)., Methods: Three randomized, double-blind, placebo- and active-controlled crossover studies were conducted in recreational drug users to evaluate the abuse-related effects of oral SDX (120 and 240 mg) vs. extended-release (ER) d-MPH (80 mg) and phentermine (60 mg); IN SDX (80 mg) vs. d-MPH (40 mg), and IV SDX (30 mg) vs. d-MPH (15 mg). Abuse-related subjective measures, pharmacokinetics, and safety were assessed., Results: The primary endpoint of maximum (E
max ) Drug Liking (DL) (0-100-point scale) was significantly higher following d-MPH vs. placebo, validating the studies. In the oral study, DL Emax was significantly higher following 80 mg ER d-MPH (Emax = 81.5) than 120 mg SDX (Emax = 62.8, p < .001) and 240 mg SDX (Emax = 63.8, p = .006); and following 60 mg phentermine (Emax = 80.2) than 120 mg SDX ( p = .0195), but not 240 mg SDX ( p = .0665). DL Emax scores were significantly higher following IN d-MPH vs SDX (Emax = 93.2 vs. 71.0, p < .0001) and following IV d-MPH vs. SDX (Emax = 84.3 vs. 56.6, p = .001). Intravenous SDX was non-inferior to placebo ( p = .001) for DL Emax . Secondary endpoints (e.g. Take Drug Again) were generally consistent with the primary endpoint. Maximal and overall d-MPH exposure was lower for SDX than d-MPH for all routes. Adverse events typical of stimulants were more frequent with d-MPH than SDX., Conclusions: These findings indicate that the novel d-MPH prodrug, SDX, has lower abuse potential than d-MPH and support its classification as a C-IV controlled substance.- Published
- 2022
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46. Extensively Drug-Resistant Klebsiella pneumoniae Counteracts Fitness and Virulence Costs That Accompanied Ceftazidime-Avibactam Resistance Acquisition.
- Author
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Eger E, Schwabe M, Schulig L, Hübner NO, Bohnert JA, Bornscheuer UT, Heiden SE, Müller JU, Adnan F, Becker K, Correa-Martinez CL, Guenther S, Idelevich EA, Baecker D, and Schaufler K
- Subjects
- Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Azabicyclo Compounds, Bacterial Proteins genetics, Bacterial Proteins metabolism, Ceftazidime, Drug Combinations, Humans, Microbial Sensitivity Tests, Porins, Virulence genetics, beta-Lactamases genetics, Klebsiella Infections drug therapy, Klebsiella Infections microbiology, Klebsiella pneumoniae genetics, Klebsiella pneumoniae metabolism
- Abstract
The ability of extensively drug-resistant (XDR) Klebsiella pneumoniae to rapidly acquire resistance to novel antibiotics is a global concern. Moreover, Klebsiella clonal lineages that successfully combine resistance and hypervirulence have increasingly occurred during the last years. However, the underlying mechanisms of counteracting fitness costs that accompany antibiotic resistance acquisition remain largely unexplored. Here, we investigated whether and how an XDR sequence type (ST)307 K. pneumoniae strain developed resistance against the novel drug combination ceftazidime-avibactam (CAZ-AVI) using experimental evolution. In addition, we performed in vitro and in vivo assays, molecular modeling, and bioinformatics to identify resistance-conferring processes and explore the resulting decrease in fitness and virulence. The subsequent amelioration of the initial costs was also addressed. We demonstrate that distinct mutations of the major nonselective porin OmpK36 caused CAZ-AVI resistance that persists even upon following a second experimental evolution without antibiotic selection pressure and that the Klebsiella strain compensates the resulting fitness and virulence costs. Furthermore, the genomic and transcriptomic analyses suggest the envelope stress response regulator rpoE and associated RpoE-regulated genes as drivers of this compensation. This study verifies the crucial role of OmpK36 in CAZ-AVI resistance and shows the rapid adaptation of a bacterial pathogen to compensate fitness- and virulence-associated resistance costs, which possibly contributes to the emergence of successful clonal lineages. IMPORTANCE Extensively drug-resistant Klebsiella pneumoniae causing major outbreaks and severe infections has become a significant challenge for health care systems worldwide. Rapid resistance development against last-resort therapeutics like ceftazidime-avibactam is a significant driver for the accelerated emergence of such pathogens. Therefore, it is crucial to understand what exactly mediates rapid resistance acquisition and how bacterial pathogens counteract accompanying fitness and virulence costs. By combining bioinformatics with in vitro and in vivo phenotypic approaches, this study revealed the critical role of mutations in a particular porin channel in ceftazidime-avibactam resistance development and a major metabolic regulator for ameliorating fitness and virulence costs. These results highlight underlying mechanisms and contribute to the understanding of factors important for the emergence of successful bacterial pathogens.
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- 2022
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47. FGF10 Triggers De Novo Alveologenesis in a Bronchopulmonary Dysplasia Model: Impact on Resident Mesenchymal Niche Cells.
- Author
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Taghizadeh S, Chao CM, Guenther S, Glaser L, Gersmann L, Michel G, Kraut S, Goth K, Koepke J, Heiner M, Vazquez-Armendariz AI, Herold S, Samakovlis C, Weissmann N, Ricci F, Aquila G, Boyer L, Ehrhardt H, Minoo P, Bellusci S, and Rivetti S
- Subjects
- Animals, Animals, Newborn, Fibroblast Growth Factor 10 genetics, Fibroblast Growth Factor 10 metabolism, Humans, Infant, Newborn, Lung metabolism, Mice, Mice, Transgenic, Bronchopulmonary Dysplasia genetics, Bronchopulmonary Dysplasia metabolism, Hyperoxia metabolism
- Abstract
Bronchopulmonary dysplasia (BPD) is a neonatal lung disease developing in premature babies characterized by arrested alveologenesis and associated with decreased Fibroblast growth factor 10 (FGF10) expression. One-week hyperoxia (HYX) exposure of newborn mice leads to a permanent arrest in alveologenesis. To test the role of Fgf10 signaling to promote de novo alveologenesis following hyperoxia, we used transgenic mice allowing inducible expression of Fgf10 and recombinant FGF10 (rFGF10) protein delivered intraperitoneally. We carried out morphometry analysis, and IF on day 45. Alveolospheres assays were performed co-culturing AT2s from normoxia (NOX) with FACS-isolated Sca1Pos resident mesenchymal cells (rMC) from animals exposed to NOX, HYX-PBS, or HYX-FGF10. scRNAseq between rMC-Sca1Pos isolated from NOX and HYX-PBS was also carried out. Transgenic overexpression of Fgf10 and rFGF10 administration rescued the alveologenesis defects following HYX. Alveolosphere assays indicate that the activity of rMC-Sca1Pos is negatively impacted by HYX and partially rescued by rFGF10 treatment. Analysis by IF demonstrates a significant impact of rFGF10 on the activity of resident mesenchymal cells. scRNAseq results identified clusters expressing Fgf10, Fgf7, Pdgfra, and Axin2, which could represent the rMC niche cells for the AT2 stem cells. In conclusion, we demonstrate that rFGF10 administration is able to induce de novo alveologenesis in a BPD mouse model and identified subpopulations of rMC-Sca1Pos niche cells potentially representing its cellular target., (© The Author(s) 2022. Published by Oxford University Press.)
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- 2022
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48. WNT/RYK signaling functions as an antiinflammatory modulator in the lung mesenchyme.
- Author
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Kim HT, Panza P, Kikhi K, Nakamichi Y, Atzberger A, Guenther S, Ruppert C, Guenther A, and Stainier DYR
- Subjects
- Animals, Humans, Lung enzymology, Lung growth & development, Mesoderm metabolism, Mice, NF-kappa B metabolism, Stromal Cells metabolism, Pneumonia enzymology, Pneumonia genetics, Receptor Protein-Tyrosine Kinases genetics, Receptor Protein-Tyrosine Kinases metabolism, Wnt Signaling Pathway, beta Catenin genetics, beta Catenin metabolism
- Abstract
A number of inflammatory lung diseases, including chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and pneumonia, are modulated by WNT/β-catenin signaling. However, the underlying molecular mechanisms remain unclear. Here, starting with a forward genetic screen in mouse, we identify the WNT coreceptor Related to receptor tyrosine kinase (RYK) acting in mesenchymal tissues as a cell survival and antiinflammatory modulator. Ryk mutant mice exhibit lung hypoplasia and inflammation as well as alveolar simplification due to defective secondary septation, and deletion of Ryk specifically in mesenchymal cells also leads to these phenotypes. By analyzing the transcriptome of wild-type and mutant lungs, we observed the up-regulation of proapoptotic and inflammatory genes whose expression can be repressed by WNT/RYK signaling in vitro. Moreover, mesenchymal Ryk deletion at postnatal and adult stages can also lead to lung inflammation, thus indicating a continued role for WNT/RYK signaling in homeostasis. Our results indicate that RYK signaling through β-catenin and Nuclear Factor kappa B (NF-κB) is part of a safeguard mechanism against mesenchymal cell death, excessive inflammatory cytokine production, and inflammatory cell recruitment and accumulation. Notably, RYK expression is down-regulated in the stromal cells of pneumonitis patient lungs. Altogether, our data reveal that RYK signaling plays critical roles as an antiinflammatory modulator during lung development and homeostasis and provide an animal model to further investigate the etiology of, and therapeutic approaches to, inflammatory lung diseases.
- Published
- 2022
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49. Regulatory and Enterotoxin Gene Expression and Enterotoxins Production in Staphylococcus aureus FRI913 Cultures Exposed to a Rotating Magnetic Field and trans -Anethole.
- Author
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Kwiatkowski P, Tabiś A, Fijałkowski K, Masiuk H, Łopusiewicz Ł, Pruss A, Sienkiewicz M, Wardach M, Kurzawski M, Guenther S, Bania J, Dołęgowska B, and Wojciechowska-Koszko I
- Subjects
- Allylbenzene Derivatives, Anisoles, Gene Expression, Humans, Magnetic Fields, Staphylococcus aureus genetics, Staphylococcus aureus metabolism, Enterotoxins genetics, Enterotoxins metabolism, Staphylococcal Infections microbiology
- Abstract
The study aimed to examine the influence of a rotating magnetic field (RMF) of two different frequencies (5 and 50 Hz) on the expression of regulatory ( agrA , hld , rot ) and staphylococcal enterotoxin (SE- sea , sec , sel ) genes as well as the production of SEs (SEA, SEC, SEL) by the Staphylococcus aureus FRI913 strain cultured on a medium supplemented with a subinhibitory concentration of trans -anethole (TA). Furthermore, a theoretical model of interactions between the bacterial medium and bacterial cells exposed to RMF was proposed. Gene expression and SEs production were measured using quantitative real-time PCR and ELISA techniques, respectively. Based on the obtained results, it was found that there were no significant differences in the expression of regulatory and SE genes in bacteria simultaneously cultured on a medium supplemented with TA and exposed to RMF at the same time in comparison to the control (unexposed to TA and RMF). In contrast, when the bacteria were cultured on a medium supplemented with TA but were not exposed to RMF or when they were exposed to RMF of 50 Hz (but not to TA), a significant increase in agrA and sea transcripts as compared to the unexposed control was found. Moreover, the decreased level of sec transcripts in bacteria cultured without TA but exposed to RMF of 50 Hz was also revealed. In turn, a significant increase in SEA and decrease in SEC and SEL production was observed in bacteria cultured on a medium supplemented with TA and simultaneously exposed to RMFs. It can be concluded, that depending on SE and regulatory genes expression as well as production of SEs, the effect exerted by the RMF and TA may be positive (i.e., manifests as the increase in SEs and/or regulatory gene expression of SEs production) or negative (i.e., manifests as the reduction in both aforementioned features) or none.
- Published
- 2022
- Full Text
- View/download PDF
50. A YAP/TAZ-TEAD signalling module links endothelial nutrient acquisition to angiogenic growth.
- Author
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Ong YT, Andrade J, Armbruster M, Shi C, Castro M, Costa ASH, Sugino T, Eelen G, Zimmermann B, Wilhelm K, Lim J, Watanabe S, Guenther S, Schneider A, Zanconato F, Kaulich M, Pan D, Braun T, Gerhardt H, Efeyan A, Carmeliet P, Piccolo S, Grosso AR, and Potente M
- Subjects
- Acyltransferases metabolism, Animals, Mechanistic Target of Rapamycin Complex 1 metabolism, Mice, Nutrients, TEA Domain Transcription Factors metabolism, YAP-Signaling Proteins metabolism, Endothelial Cells metabolism, Trans-Activators metabolism
- Abstract
Angiogenesis, the process by which endothelial cells (ECs) form new blood vessels from existing ones, is intimately linked to the tissue's metabolic milieu and often occurs at nutrient-deficient sites. However, ECs rely on sufficient metabolic resources to support growth and proliferation. How endothelial nutrient acquisition and usage are regulated is unknown. Here we show that these processes are instructed by Yes-associated protein 1 (YAP)/WW domain-containing transcription regulator 1 (WWTR1/TAZ)-transcriptional enhanced associate domain (TEAD): a transcriptional module whose function is highly responsive to changes in the tissue environment. ECs lacking YAP/TAZ or their transcriptional partners, TEAD1, 2 and 4 fail to divide, resulting in stunted vascular growth in mice. Conversely, activation of TAZ, the more abundant paralogue in ECs, boosts proliferation, leading to vascular hyperplasia. We find that YAP/TAZ promote angiogenesis by fuelling nutrient-dependent mTORC1 signalling. By orchestrating the transcription of a repertoire of cell-surface transporters, including the large neutral amino acid transporter SLC7A5, YAP/TAZ-TEAD stimulate the import of amino acids and other essential nutrients, thereby enabling mTORC1 activation. Dissociating mTORC1 from these nutrient inputs-elicited by the loss of Rag GTPases-inhibits mTORC1 activity and prevents YAP/TAZ-dependent vascular growth. Together, these findings define a pivotal role for YAP/TAZ-TEAD in controlling endothelial mTORC1 and illustrate the essentiality of coordinated nutrient fluxes in the vasculature., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
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