83 results on '"P Maas"'
Search Results
2. Trained immunity is regulated by T cell-induced CD40-TRAF6 signaling
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Maaike M.E. Jacobs, Rianne J.F. Maas, Inge Jonkman, Yutaka Negishi, Willem Tielemans Zamora, Cansu Yanginlar, Julia van Heck, Vasiliki Matzaraki, Joost H.A. Martens, Marijke Baltissen, Michiel Vermeulen, Judit Morla-Folch, Anna Ranzenigo, William Wang, Martin Umali, Jordi Ochando, Johan van der Vlag, Luuk B. Hilbrands, Leo A.B. Joosten, Mihai G. Netea, Willem J.M. Mulder, Mandy M.T. van Leent, Musa M. Mhlanga, Abraham J.P. Teunissen, Nils Rother, and Raphaël Duivenvoorden
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CP: Immunology ,Biology (General) ,QH301-705.5 - Abstract
Summary: Trained immunity is characterized by histone modifications and metabolic changes in innate immune cells following exposure to inflammatory signals, leading to heightened responsiveness to secondary stimuli. Although our understanding of the molecular regulation of trained immunity has increased, the role of adaptive immune cells herein remains largely unknown. Here, we show that T cells modulate trained immunity via cluster of differentiation 40-tissue necrosis factor receptor-associated factor 6 (CD40-TRAF6) signaling. CD40-TRAF6 inhibition modulates functional, transcriptomic, and metabolic reprogramming and modifies histone 3 lysine 4 trimethylation associated with trained immunity. Besides in vitro studies, we reveal that single-nucleotide polymorphisms in the proximity of CD40 are linked to trained immunity responses in vivo and that combining CD40-TRAF6 inhibition with cytotoxic T lymphocyte antigen 4-immunoglobulin (CTLA4-Ig)-mediated co-stimulatory blockade induces long-term graft acceptance in a murine heart transplantation model. Combined, our results reveal that trained immunity is modulated by CD40-TRAF6 signaling between myeloid and adaptive immune cells and that this can be leveraged for therapeutic purposes.
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- 2024
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3. Generation and preclinical evaluation of a human heavy-chain-only antibody recognizing the membrane-bound tumor-associated antigen mesothelin
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Rick Janssens, Rien van Haperen, Michael van der Reijden, Alex Maas, Jingsong Wang, Frank Grosveld, and Dubravka Drabek
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mesothelin (MSLN) ,heavy-chain-only antibody (HCAb) ,OVCAR-3 tumor ,radioimaging ,SPECT and PET imaging ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
ObjectiveMesothelin (MSLN) is an attractive target for anticancer therapeutics and bioimaging reagents that utilize antibodies. This study was aimed at developing a novel human anti-MSLN single-domain antibody that exclusively binds to the membrane-attached MSLN using transgenic mice generating human heavy-chain-only antibodies (HCAbs) and exploring the resulting HCAbs as imaging tools.MethodsWe introduced a doxycycline-inducible human MSLN gene in genetically modified mice expressing human HCAbs. This new method of non-invasive immunization by antigen induction results in MSLN antigen production in its native conformation on the cell surface. Screening of 2,000 HCAbs from the resulting immune library yielded numerous binders, from which we chose 19G6 as the lead antibody. This antibody was 111Indium radiolabeled and tested in a xenotransplantation tumor model with OVCAR-3 cells.ResultsThe 19G6 antibody shows nanomolar affinity toward membrane-bound MSLN and does not recognize soluble MSLN. The human MSLN-positive tumors were visualized in an in vivo mouse model. The non-labeled antibody prevented binding when provided in excess, showing tumor specificity.Conclusion19G6 with a human Fc is a promising tumor-cell tracer in vivo. This HCAb can also be engineered into a smaller and shorter-lived tracer (only the VH domain) or combined with other target-binding domains to form multispecific modalities for tumor immunotherapy.
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- 2024
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4. Internal and external normalization of nascent RNA sequencing run-on experiments
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Zachary L. Maas and Robin D. Dowell
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Nascent RNA sequencing ,Normalization ,Bayesian ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Biology (General) ,QH301-705.5 - Abstract
Abstract In experiments with significant perturbations to transcription, nascent RNA sequencing protocols are dependent on external spike-ins for reliable normalization. Unlike in RNA-seq, these spike-ins are not standardized and, in many cases, depend on a run-on reaction that is assumed to have constant efficiency across samples. To assess the validity of this assumption, we analyze a large number of published nascent RNA spike-ins to quantify their variability across existing normalization methods. Furthermore, we develop a new biologically-informed Bayesian model to estimate the error in spike-in based normalization estimates, which we term Virtual Spike-In (VSI). We apply this method both to published external spike-ins as well as using reads at the $$3^\prime$$ 3 ′ end of long genes, building on prior work from Mahat (Mol Cell 62(1):63–78, 2016. https://doi.org/10.1016/j.molcel.2016.02.025 ) and Vihervaara (Nat Commun 8(1):255, 2017. https://doi.org/10.1038/s41467-017-00151-0 ). We find that spike-ins in existing nascent RNA experiments are typically under sequenced, with high variability between samples. Furthermore, we show that these high variability estimates can have significant downstream effects on analysis, complicating biological interpretations of results.
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- 2024
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5. Comparison of IMU-Based Knee Kinematics with and without Harness Fixation against an Optical Marker-Based System
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Jana G. Weber, Ariana Ortigas-Vásquez, Adrian Sauer, Ingrid Dupraz, Michael Utz, Allan Maas, and Thomas M. Grupp
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IMU ,gait analysis ,knee kinematics ,REFRAME ,motion capture ,movement biomechanics ,Technology ,Biology (General) ,QH301-705.5 - Abstract
The use of inertial measurement units (IMUs) as an alternative to optical marker-based systems has the potential to make gait analysis part of the clinical standard of care. Previously, an IMU-based system leveraging Rauch–Tung–Striebel smoothing to estimate knee angles was assessed using a six-degrees-of-freedom joint simulator. In a clinical setting, however, accurately measuring abduction/adduction and external/internal rotation of the knee joint is particularly challenging, especially in the presence of soft tissue artefacts. In this study, the in vivo IMU-based joint angles of 40 asymptomatic knees were assessed during level walking, under two distinct sensor placement configurations: (1) IMUs fixed to a rigid harness, and (2) IMUs mounted on the skin using elastic hook-and-loop bands (from here on referred to as “skin-mounted IMUs”). Estimates were compared against values obtained from a harness-mounted optical marker-based system. The comparison of these three sets of kinematic signals (IMUs on harness, IMUs on skin, and optical markers on harness) was performed before and after implementation of a REference FRame Alignment MEthod (REFRAME) to account for the effects of differences in coordinate system orientations. Prior to the implementation of REFRAME, in comparison to optical estimates, skin-mounted IMU-based angles displayed mean root-mean-square errors (RMSEs) up to 6.5°, while mean RMSEs for angles based on harness-mounted IMUs peaked at 5.1°. After REFRAME implementation, peak mean RMSEs were reduced to 4.1°, and 1.5°, respectively. The negligible differences between harness-mounted IMUs and the optical system after REFRAME revealed that the IMU-based system was capable of capturing the same underlying motion pattern as the optical reference. In contrast, obvious differences between the skin-mounted IMUs and the optical reference indicated that the use of a harness led to fundamentally different joint motion being measured, even after accounting for reference frame misalignments. Fluctuations in the kinematic signals associated with harness use suggested the rigid device oscillated upon heel strike, likely due to inertial effects from its additional mass. Our study proposes that optical systems can be successfully replaced by more cost-effective IMUs with similar accuracy, but further investigation (especially in vivo and upon heel strike) against moving videofluoroscopy is recommended.
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- 2024
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6. Shifts in dominance of benthic communities along a gradient of water temperature and turbidity in tropical coastal ecosystems
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Ludi Parwadani Aji, Diede Louise Maas, Agustin Capriati, Awaludinnoer Ahmad, Christiaan de Leeuw, and Leontine Elisabeth Becking
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Benthic cover ,Biodiversity ,Coral reef ,Marine lake ,Anthropogenic pressures ,Raja Ampat (Indonesia) ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
Tropical coastal benthic communities will change in species composition and relative dominance due to global (e.g., increasing water temperature) and local (e.g., increasing terrestrial influence due to land-based activity) stressors. This study aimed to gain insight into possible trajectories of coastal benthic assemblages in Raja Ampat, Indonesia, by studying coral reefs at varying distances from human activities and marine lakes with high turbidity in three temperature categories (32 °C). The benthic community diversity and relative coverage of major benthic groups were quantified via replicate photo transects. The composition of benthic assemblages varied significantly among the reef and marine lake habitats. The marine lakes 32 °C) did not harbor hard coral or CCA. Benthic composition in the reefs was significantly influenced by geographic distance among sites but not by human activity or depth. Benthic composition in the marine lakes appeared to be structured by temperature, salinity, and degree of connection to the adjacent sea. Our results suggest that beyond a certain temperature (>31 °C), benthic communities shift away from coral dominance, but new outcomes of assemblages can be highly distinct, with a possible varied dominance of macroalgae, benthic cyanobacterial mats, or filter feeders such as bivalves and tubeworms. This study illustrates the possible use of marine lake model systems to gain insight into shifts in the benthic community structure of tropical coastal ecosystems if hard corals are no longer dominant.
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- 2024
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7. Modifying the Secretome of Mesenchymal Stem Cells Prolongs the Regenerative Treatment Window for Encephalopathy of Prematurity
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Josine E. G. Vaes, Suzanne M. Onstwedder, Chloe Trayford, Eva Gubbins, Mirjam Maas, Sabine H. van Rijt, and Cora H. Nijboer
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preterm birth ,Encephalopathy of Prematurity ,oligodendrocytes ,central nervous system ,mesenchymal stem cells ,glia ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Clinical treatment options to combat Encephalopathy of Prematurity (EoP) are still lacking. We, and others, have proposed (intranasal) mesenchymal stem cells (MSCs) as a potent therapeutic strategy to boost white matter repair in the injured preterm brain. Using a double-hit mouse model of diffuse white matter injury, we previously showed that the efficacy of MSC treatment was time dependent, with a significant decrease in functional and histological improvements after the postponement of cell administration. In this follow-up study, we aimed to investigate the mechanisms underlying this loss of therapeutic efficacy. Additionally, we optimized the regenerative potential of MSCs by means of genetic engineering with the transient hypersecretion of beneficial factors, in order to prolong the treatment window. Though the cerebral expression of known chemoattractants was stable over time, the migration of MSCs to the injured brain was partially impaired. Moreover, using a primary oligodendrocyte (OL) culture, we showed that the rescue of injured OLs was reduced after delayed MSC coculture. Cocultures of modified MSCs, hypersecreting IGF1, LIF, IL11, or IL10, with primary microglia and OLs, revealed a superior treatment efficacy over naïve MSCs. Additionally, we showed that the delayed intranasal administration of IGF1-, LIF-, or IL11-hypersecreting MSCs, improved myelination and the functional outcome in EoP mice. In conclusion, the impaired migration and regenerative capacity of intranasally applied MSCs likely underlie the observed loss of efficacy after delayed treatment. The intranasal administration of IGF1-, LIF-, or IL11-hypersecreting MSCs, is a promising optimization strategy to prolong the window for effective MSC treatment in preterm infants with EoP.
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- 2024
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8. Navigating the Maze of Kinases: CaMK-like Family Protein Kinases and Their Role in Atherosclerosis
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Jules T. J. Teuwen, Emiel P. C. van der Vorst, and Sanne L. Maas
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kinases ,CAMKL family ,atherosclerosis ,inflammation ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Circulating low-density lipoprotein (LDL) levels are a major risk factor for cardiovascular diseases (CVD), and even though current treatment strategies focusing on lowering lipid levels are effective, CVD remains the primary cause of death worldwide. Atherosclerosis is the major cause of CVD and is a chronic inflammatory condition in which various cell types and protein kinases play a crucial role. However, the underlying mechanisms of atherosclerosis are not entirely understood yet. Notably, protein kinases are highly druggable targets and represent, therefore, a novel way to target atherosclerosis. In this review, the potential role of the calcium/calmodulin-dependent protein kinase-like (CaMKL) family and its role in atherosclerosis will be discussed. This family consists of 12 subfamilies, among which are the well-described and conserved liver kinase B1 (LKB1) and 5′ adenosine monophosphate-activated protein kinase (AMPK) subfamilies. Interestingly, LKB1 plays a key role and is considered a master kinase within the CaMKL family. It has been shown that LKB1 signaling leads to atheroprotective effects, while, for example, members of the microtubule affinity-regulating kinase (MARK) subfamily have been described to aggravate atherosclerosis development. These observations highlight the importance of studying kinases and their signaling pathways in atherosclerosis, bringing us a step closer to unraveling the underlying mechanisms of atherosclerosis.
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- 2024
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9. Identifying Differences in Molecular Characteristics Relevant for Remodeling of Periodontal Ligament Stem Cells from the Upper and Lower Jaw
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Hanna Malyaran, Rogerio B. Craveiro, Sinan Mert, Christian Niederau, Sanne L. Maas, Emiel P. C. van der Vorst, Frank Hölzle, Wilhelm Jahnen-Dechent, Michael Wolf, and Sabine Neuss
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kinase activity ,periodontal ligament stem cells ,mandible ,maxilla ,tyrosine ,serine/threonine ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Periodontal defects’ localization affects wound healing and bone remodeling, with faster healing in the upper jaw compared to the lower jaw. While differences in blood supply, innervation, and odontogenesis contribute, cell-intrinsic variances may exist. Few studies explored cell signaling in periodontal ligament stem cells (PDLSC), overlooking mandible-maxilla disparitiesUsing kinomics technology, we investigated molecular variances in PDLSC. Characterization involved stem cell surface markers, proliferation, and differentiation capacities. Kinase activity was analyzed via multiplex kinase profiling, mapping differential activity in known gene regulatory networks. Upstream kinase analysis identified stronger EphA receptor expression in the mandible, potentially inhibiting osteogenic differentiation. The PI3K-Akt pathway showed higher activity in lower-jaw PDLSC. PDLSC from the upper jaw exhibit superior proliferation and differentiation capabilities. Differential activation of gene regulatory pathways in upper vs. lower-jaw PDLSC suggests implications for regenerative therapies.
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- 2024
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10. Multi-Omics Analysis of Gut Microbiota and Host Transcriptomics Reveal Dysregulated Immune Response and Metabolism in Young Adults with Irritable Bowel Syndrome
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Jie Chen, Tingting Zhao, Hongfei Li, Wanli Xu, Kendra Maas, Vijender Singh, Ming-Hui Chen, Susan G. Dorsey, Angela R. Starkweather, and Xiaomei S. Cong
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irritable bowel syndrome ,gut microbiome ,gene expression profiling ,immunity ,metabolic processes ,multi-omics ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The integrated dysbiosis of gut microbiota and altered host transcriptomics in irritable bowel syndrome (IBS) is yet to be known. This study investigated the associations among gut microbiota and host transcriptomics in young adults with IBS. Stool and peripheral blood samples from 20 IBS subjects and 21 healthy controls (HCs) collected at the baseline visit of an RCT were sequenced to depict the gut microbiota and transcriptomic profiles, respectively. The diversities, composition, and predicted metabolic pathways of gut microbiota significantly differed between IBS subjects and HCs. Nine genera were significantly abundant in IBS stool samples, including Akkermansia, Blautia, Coprococcus, Granulicatella, Holdemania, Oribacterium, Oscillospira, Parabacteroides, and Sutterella. There were 2264 DEGs found between IBS subjects and HCs; 768 were upregulated, and 1496 were downregulated in IBS participants compared with HCs. The enriched gene ontology included the immune system process and immune response. The pathway of antigen processing and presentation (hsa04612) in gut microbiota was also significantly different in the RNA-seq data. Akkermansia, Blautia, Holdemania, and Sutterella were significantly correlated with ANXA2P2 (upregulated, positive correlations), PCSK1N (downregulated, negative correlations), and GLTPD2 (downregulated, negative correlations). This study identified the dysregulated immune response and metabolism in IBS participants revealed by the altered gut microbiota and transcriptomic profiles.
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- 2024
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11. Spatial Configurations of 3D Extracellular Matrix Collagen Density and Anisotropy Simultaneously Guide Angiogenesis.
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Steven A LaBelle, A Marsh Poulson, Steve A Maas, Adam Rauff, Gerard A Ateshian, and Jeffrey A Weiss
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Biology (General) ,QH301-705.5 - Abstract
Extracellular matrix (ECM) collagen density and fibril anisotropy are thought to affect the development of new vasculatures during pathologic and homeostatic angiogenesis. Computational simulation is emerging as a tool to investigate the role of matrix structural configurations on cell guidance. However, prior computational models have only considered the orientation of collagen as a model input. Recent experimental evidence indicates that cell guidance is simultaneously influenced by the direction and intensity of alignment (i.e., degree of anisotropy) as well as the local collagen density. The objective of this study was to explore the role of ECM collagen anisotropy and density during sprouting angiogenesis through simulation in the AngioFE and FEBio modeling frameworks. AngioFE is a plugin for FEBio (Finite Elements for Biomechanics) that simulates cell-matrix interactions during sprouting angiogenesis. We extended AngioFE to represent ECM collagen as deformable 3D ellipsoidal fibril distributions (EFDs). The rate and direction of microvessel growth were modified to depend simultaneously on the ECM collagen anisotropy (orientation and degree of anisotropy) and density. The sensitivity of growing neovessels to these stimuli was adjusted so that AngioFE could reproduce the growth and guidance observed in experiments where microvessels were cultured in collagen gels of varying anisotropy and density. We then compared outcomes from simulations using EFDs to simulations that used AngioFE's prior vector field representation of collagen anisotropy. We found that EFD simulations were more accurate than vector field simulations in predicting experimentally observed microvessel guidance. Predictive simulations demonstrated the ability of anisotropy gradients to recruit microvessels across short and long distances relevant to wound healing. Further, simulations predicted that collagen alignment could enable microvessels to overcome dense tissue interfaces such as tumor-associated collagen structures (TACS) found in desmoplasia and tumor-stroma interfaces. This approach can be generalized to other mechanobiological relationships during cell guidance phenomena in computational settings.
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- 2023
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12. SMOC-1 interacts with both BMP and glypican to regulate BMP signaling in C. elegans.
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Melisa S DeGroot, Byron Williams, Timothy Y Chang, Maria L Maas Gamboa, Isabel M Larus, Garam Hong, J Christopher Fromme, and Jun Liu
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Biology (General) ,QH301-705.5 - Abstract
Secreted modular calcium-binding proteins (SMOCs) are conserved matricellular proteins found in organisms from Caenorhabditis elegans to humans. SMOC homologs characteristically contain 1 or 2 extracellular calcium-binding (EC) domain(s) and 1 or 2 thyroglobulin type-1 (TY) domain(s). SMOC proteins in Drosophila and Xenopus have been found to interact with cell surface heparan sulfate proteoglycans (HSPGs) to exert both positive and negative influences on the conserved bone morphogenetic protein (BMP) signaling pathway. In this study, we used a combination of biochemical, structural modeling, and molecular genetic approaches to dissect the functions of the sole SMOC protein in C. elegans. We showed that CeSMOC-1 binds to the heparin sulfate proteoglycan GPC3 homolog LON-2/glypican, as well as the mature domain of the BMP2/4 homolog DBL-1. Moreover, CeSMOC-1 can simultaneously bind LON-2/glypican and DBL-1/BMP. The interaction between CeSMOC-1 and LON-2/glypican is mediated specifically by the EC domain of CeSMOC-1, while the full interaction between CeSMOC-1 and DBL-1/BMP requires full-length CeSMOC-1. We provide both in vitro biochemical and in vivo functional evidence demonstrating that CeSMOC-1 functions both negatively in a LON-2/glypican-dependent manner and positively in a DBL-1/BMP-dependent manner to regulate BMP signaling. We further showed that in silico, Drosophila and vertebrate SMOC proteins can also bind to mature BMP dimers. Our work provides a mechanistic basis for how the evolutionarily conserved SMOC proteins regulate BMP signaling.
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- 2023
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13. The ATM Ser49Cys Variant Effects ATM Function as a Regulator of Oncogene-Induced Senescence
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Caroline Atkinson, Aideen M. McInerney-Leo, Martina Proctor, Catherine Lanagan, Alexander J. Stevenson, Farhad Dehkhoda, Mary Caole, Ellie Maas, Stephen Ainger, Antonia L. Pritchard, Peter A. Johansson, Paul Leo, Nicholas K. Hayward, Richard A. Sturm, Emma L. Duncan, and Brian Gabrielli
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ATM ,p53 ,ionising radiation ,DNA damage ,senescence ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
An apical component of the cell cycle checkpoint and DNA damage repair response is the ataxia-telangiectasia mutated (ATM) Ser/Thr protein kinase. A variant of ATM, Ser49Cys (rs1800054; minor allele frequency = 0.011), has been associated with an elevated risk of melanoma development; however, the functional consequence of this variant is not defined. ATM-dependent signalling in response to DNA damage has been assessed in a panel of patient-derived lymphoblastoid lines and primary human melanocytic cell strains heterozygous for the ATM Ser49Cys variant allele. The ATM Ser49Cys allele appears functional for acute p53-dependent signalling in response to DNA damage. Expression of the variant allele did reduce the efficacy of oncogene expression in inducing senescence. These findings demonstrate that the ATM 146C>G Ser49Cys allele has little discernible effect on the acute response to DNA damage but has reduced function observed in the chronic response to oncogene over-expression. Analysis of melanoma, naevus and skin colour genomics and GWAS analyses have demonstrated no association of this variant with any of these outcomes. The modest loss of function detected suggest that the variant may act as a modifier of other variants of ATM/p53-dependent signalling.
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- 2024
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14. Functional Insight into and Refinement of the Genomic Boundaries of the JARID2-Neurodevelopmental Disorder Episignature
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Liselot van der Laan, Kathleen Rooney, Sadegheh Haghshenas, Ananília Silva, Haley McConkey, Raissa Relator, Michael A. Levy, Irene Valenzuela, Laura Trujillano, Amaia Lasa-Aranzasti, Berta Campos, Neus Castells, Eline A. Verberne, Saskia Maas, Mariëlle Alders, Marcel M. A. M. Mannens, Mieke M. van Haelst, Bekim Sadikovic, and Peter Henneman
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JARID2 ,CNV ,DNA methylation ,episignature ,intellectual disability ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
JARID2 (Jumonji, AT-rich interactive domain 2) haploinsufficiency is associated with a clinically distinct neurodevelopmental syndrome. It is characterized by intellectual disability, developmental delay, autistic features, behavior abnormalities, cognitive impairment, hypotonia, and dysmorphic features. JARID2 acts as a transcriptional repressor protein that is involved in the regulation of histone methyltransferase complexes. JARID2 plays a role in the epigenetic machinery, and the associated syndrome has an identified DNA methylation episignature derived from sequence variants and intragenic deletions involving JARID2. For this study, our aim was to determine whether patients with larger deletions spanning beyond JARID2 present a similar DNA methylation episignature and to define the critical region involved in aberrant DNA methylation in 6p22–p24 microdeletions. We examined the DNA methylation profiles of peripheral blood from 56 control subjects, 13 patients with (likely) pathogenic JARID2 variants or patients carrying copy number variants, and three patients with JARID2 VUS variants. The analysis showed a distinct and strong differentiation between patients with (likely) pathogenic variants, both sequence and copy number, and controls. Using the identified episignature, we developed a binary model to classify patients with the JARID2-neurodevelopmental syndrome. DNA methylation analysis indicated that JARID2 is the driver gene for aberrant DNA methylation observed in 6p22–p24 microdeletions. In addition, we performed analysis of functional correlation of the JARID2 genome-wide methylation profile with the DNA methylation profiles of 56 additional neurodevelopmental disorders. To conclude, we refined the critical region for the presence of the JARID2 episignature in 6p22–p24 microdeletions and provide insight into the functional changes in the epigenome observed when regulation by JARID2 is lost.
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- 2023
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15. Transcription factor enrichment analysis (TFEA) quantifies the activity of multiple transcription factors from a single experiment
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Jonathan D. Rubin, Jacob T. Stanley, Rutendo F. Sigauke, Cecilia B. Levandowski, Zachary L. Maas, Jessica Westfall, Dylan J. Taatjes, and Robin D. Dowell
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Biology (General) ,QH301-705.5 - Abstract
Rubin et al. introduce transcription factor enrichment analysis (TFEA), a new motif enrichment method specifically aimed at maximizing the informative nature of differential RNA polymerase initiation data. It provides an easy, rigorous, and cost-effective analysis aimed at deciphering the temporal and mechanistic details of complex regulatory networks.
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- 2021
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16. CLASP2 safeguards hematopoietic stem cell properties during mouse and fish development
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Anna Klaus, Thomas Clapes, Laurent Yvernogeau, Sreya Basu, Bart Weijts, Joris Maas, Ihor Smal, Niels Galjart, and Catherine Robin
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hematopoietic stem cells ,CLASP2 ,hemogenic endothelium ,mouse ,zebrafish ,intra-aortic hematopoietic clusters ,Biology (General) ,QH301-705.5 - Abstract
Summary: Hematopoietic stem cells (HSCs) express a large variety of cell surface receptors that are associated with acquisition of self-renewal and multipotent properties. Correct expression of these receptors depends on a delicate balance between cell surface trafficking, recycling, and degradation and is controlled by the microtubule network and Golgi apparatus, whose roles have hardly been explored during embryonic/fetal hematopoiesis. Here we show that, in the absence of CLASP2, a microtubule-associated protein, the overall production of HSCs is reduced, and the produced HSCs fail to self-renew and maintain their stemness throughout mouse and zebrafish development. This phenotype can be attributed to decreased cell surface expression of the hematopoietic receptor c-Kit, which originates from increased lysosomal degradation in combination with a reduction in trafficking to the plasma membrane. A dysfunctional Golgi apparatus in CLASP2-deficient HSCs seems to be the underlying cause of the c-Kit expression and signaling imbalance.
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- 2022
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17. Experimental Evaluation of AGV Dispatching Methods in an Agent-Based Simulation Environment and a Digital Twin
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Fabian Maas genannt Bermpohl, Andreas Bresser, and Malte Langosz
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vehicle dispatching ,agent-based simulation ,digital twin ,industry 4.0 ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
A critical part of Automated Material Handling Systems (AMHS) is the task allocation and dispatching strategy employed. In order to better understand and investigate this component, we here present an extensive experimental evaluation of three different approaches with randomly generated, as well as custom designed, environment configurations. While previous studies typically focused on use cases based on highly constrained navigation capabilities (e.g., overhead hoist transport systems), our evaluation is built around highly mobile, free-ranging vehicles, i.e., Autonomous Mobile Robots (AMR) that are gaining popularity in a broad range of applications. Consequently, our experiments are conducted using a microscopic agent-based simulation, instead of the more common discrete-event simulation model. Dispatching methods often are built around the assumption of the asynchronous evaluation of an event-based model, i.e., vehicles trigger a cascade of individual dispatching decisions, e.g., when reaching intersections. We find that this does not translate very well to a fleet of highly mobile systems that can change direction at any time. With this in mind, we present formulations of well known dispatching approaches that are better suited for a synchronous evaluation of the dispatching decisions. The formulations are based on the Stable Marriage Problem (SMP) and the Linear Sum Assignment Problem (LSAP). We use matching and assignment algorithms to compute the actual dispatching decisions. The selected algorithms are evaluated in a multi-agent simulation environment. To integrate a centralised fleet management, a digital twin concept is proposed and implemented. By this approach, the fleet management is independent of the implementation of the specific agents, allowing to quickly adapt to other simulation-based or real application scenarios. For the experimental evaluation, two new performance measures related to the efficiency of a material handling system are proposed, Travel Efficiency and Throughput Effort. The experimental evaluation indicates that reassignment mechanisms in the dispatching method can help to increase the overall efficiency of the fleet. We did not find significant differences in absolute performance in terms of throughput rate. Additionally, the difference in performance between SMP- and LSAP-based dispatching with reassignment seems negligible. We conclude with a discussion, where we consider potential confounding factors and relate the findings to previously reported results found in the literature.
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- 2023
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18. Connecting Neurobiological Features with Interregional Dysconnectivity in Social-Cognitive Impairments of Schizophrenia
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Florian W. Adraoui, Linda Douw, Gerard J. M. Martens, and Dorien A. Maas
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schizophrenia ,social cognition ,functional connectivity/dysconnectivity ,structural connectivity/dysconnectivity ,oxidative stress ,inflammation ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Schizophrenia (SZ) is a devastating psychiatric disorder affecting about 1% of the world’s population. Social-cognitive impairments in SZ prevent positive social interactions and lead to progressive social withdrawal. The neurobiological underpinnings of social-cognitive symptoms remain poorly understood, which hinders the development of novel treatments. At the whole-brain level, an abnormal activation of social brain regions and interregional dysconnectivity within social-cognitive brain networks have been identified as major contributors to these symptoms. At the cellular and subcellular levels, an interplay between oxidative stress, neuroinflammation and N-methyl-D-aspartate receptor hypofunction is thought to underly SZ pathology. However, it is not clear how these molecular processes are linked with interregional dysconnectivity in the genesis of social-cognitive symptoms. Here, we aim to bridge the gap between macroscale (connectivity analyses) and microscale (molecular and cellular mechanistic) knowledge by proposing impaired myelination and the disinhibition of local microcircuits as possible causative biological pathways leading to dysconnectivity and abnormal activity of the social brain. Furthermore, we recommend electroencephalography as a promising translational technique that can foster pre-clinical drug development and discuss attractive drug targets for the treatment of social-cognitive symptoms in SZ.
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- 2023
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19. Small-Molecule Cyclophilin Inhibitors Potently Reduce Platelet Procoagulant Activity
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Jens Van Bael, Aline Vandenbulcke, Abdelhakim Ahmed-Belkacem, Jean-François Guichou, Jean-Michel Pawlotsky, Jelle Samyn, Arjan D. Barendrecht, Coen Maas, Simon F. De Meyer, Karen Vanhoorelbeke, and Claudia Tersteeg
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Cyclophilin D ,mitochondria ,phosphatidylserine ,platelets ,procoagulant ,thrombosis ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Procoagulant platelets are associated with an increased risk for thrombosis. Procoagulant platelet formation is mediated via Cyclophilin D (CypD) mediated opening of the mitochondrial permeability transition pore. Inhibiting CypD activity could therefore be an interesting approach to limiting thrombosis. In this study, we investigated the potential of two novel, non-immunosuppressive, non-peptidic small-molecule cyclophilin inhibitors (SMCypIs) to limit thrombosis in vitro, in comparison with the cyclophilin inhibitor and immunosuppressant Cyclosporin A (CsA). Both cyclophilin inhibitors significantly decreased procoagulant platelet formation upon dual-agonist stimulation, shown by a decreased phosphatidylserine (PS) exposure, as well as a reduction in the loss of mitochondrial membrane potential. Furthermore, the SMCypIs potently reduced procoagulant platelet-dependent clotting time, as well as fibrin formation under flow, comparable to CsA. No effect was observed on agonist-induced platelet activation measured by P-selectin expression, as well as CypA-mediated integrin αIIbβ3 activation. Importantly, whereas CsA increased Adenosine 5′-diphosphate (ADP)-induced platelet aggregation, this was unaffected in the presence of the SMCypIs. We here demonstrate specific cyclophilin inhibition does not affect normal platelet function, while a clear reduction in procoagulant platelets is observed. Reducing platelet procoagulant activity by inhibiting cyclophilins with SMCypIs forms a promising strategy to limit thrombosis.
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- 2023
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20. ADAM10 and ADAM17, Major Regulators of Chronic Kidney Disease Induced Atherosclerosis?
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Sanne L. Maas, Marjo M. P. C. Donners, and Emiel P. C. van der Vorst
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a disintegrin and metalloprotease ,chronic kidney disease ,cardiovascular diseases ,atherosclerosis ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Chronic kidney disease (CKD) is a major health problem, affecting millions of people worldwide, in particular hypertensive and diabetic patients. CKD patients suffer from significantly increased cardiovascular disease (CVD) morbidity and mortality, mainly due to accelerated atherosclerosis development. Indeed, CKD not only affects the kidneys, in which injury and maladaptive repair processes lead to local inflammation and fibrosis, but also causes systemic inflammation and altered mineral bone metabolism leading to vascular dysfunction, calcification, and thus, accelerated atherosclerosis. Although CKD and CVD individually have been extensively studied, relatively little research has studied the link between both diseases. This narrative review focuses on the role of a disintegrin and metalloproteases (ADAM) 10 and ADAM17 in CKD and CVD and will for the first time shed light on their role in CKD-induced CVD. By cleaving cell surface molecules, these enzymes regulate not only cellular sensitivity to their micro-environment (in case of receptor cleavage), but also release soluble ectodomains that can exert agonistic or antagonistic functions, both locally and systemically. Although the cell-specific roles of ADAM10 and ADAM17 in CVD, and to a lesser extent in CKD, have been explored, their impact on CKD-induced CVD is likely, yet remains to be elucidated.
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- 2023
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21. Differential Expression and Clinical Relevance of C-X-C Motif Chemokine Receptor 4 (CXCR4) in Renal Cell Carcinomas, Benign Renal Tumors, and Metastases
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Moritz Maas, Aymone Kurcz, Jörg Hennenlotter, Marcus Scharpf, Falko Fend, Simon Walz, Viktoria Stühler, Tilman Todenhöfer, Arnulf Stenzl, Jens Bedke, and Steffen Rausch
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CXCR4 ,renal cancer ,molecular biomarker ,chemokines ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
C-X-C Motif Chemokine Receptor 4 (CXCR4) is part of the human chemokine system and involved in progression and metastasis in renal cell carcinoma (RCC). However, the role of CXCR4 protein expression in RCC remains controversial. In particular, data regarding the subcellular distribution of CXCR4 in RCC and RCC metastasis as well as CXCR4 expression in renal tumors of variant histology are limited. The aim of the present study was the evaluation of the differential CXCR4 expression in RCC primary tumor and metastatic tissue as well as in variant renal histologies. In addition, the prognostic capacity of CXCR4 expression in organ-confined clear cell RCC (ccRCC) was evaluated. Three independent renal tumor cohorts (primary ccRCC cohort n1 = 64; cohort of various histological entities n2 = 146; metastatic RCC tissue cohort n3 = 92) were evaluated using tissue microarrays (TMA). After immunohistochemical staining for CXCR4, nuclear and cytoplasmic expression patterns were evaluated. CXCR4 expression was correlated with validated pathologic prognosticators, clinical data, and overall and cancer-specific survival. Positive cytoplasmic staining was observed in 98% of the benign and 38.9% of the malignant samples. Nuclear staining was positive for 94.1% of the benign samples and 83% of the malignant samples. The median cytoplasmic expression score was found to be higher in benign tissue than in ccRCC (130.00 vs. 0.00); median nuclear expression score analysis indicated the opposite (56.0 vs. 71.0). Within malignant subtypes, the highest expression score was seen in papillary renal cell carcinomas (cytoplasmic: 117.50, nuclear: 41.50). Within benign renal tumors, high cytoplasmic and nuclear CXCR4 expression scores were seen for oncocytomas (cytoplasmic: 100.00, nuclear: 31.00). Expression scores in RCC metastasis ranked between benign renal tissue and ccRCC in cytoplasmic and nuclear expression. Cytoplasmic CXCR4 expression was identified as a prognostic factor for OS and CSS (p = 0.042; p = 0.019). Multivariate analysis including clinicopathological parameters did not reveal an independent prognostic character of CXCR4 expression. CXCR4 expression differs significantly within benign lesions and renal neoplasms. Cytoplasmic and nuclear expression of CXCR4 could be detected across all RCC subtypes. The prognostic value of CXCR4 in ccRCC was confirmed in univariate analysis.
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- 2023
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22. The Impact of Early Life Experiences and Gut Microbiota on Neurobehavioral Development in Preterm Infants: A Longitudinal Cohort Study
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Jie Chen, Hongfei Li, Tingting Zhao, Kun Chen, Ming-Hui Chen, Zhe Sun, Wanli Xu, Kendra Maas, Barry M. Lester, and Xiaomei S. Cong
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infants ,preterm ,NICU ,neurobehavioral development ,gut microbiota ,pain ,Biology (General) ,QH301-705.5 - Abstract
Objectives: The objective of this study is to investigate the impact of early life experiences and gut microbiota on neurobehavioral development in preterm infants during neonatal intensive care unit (NICU) hospitalization. Methods: Preterm infants were followed from NICU admission until their 28th postnatal day or until discharge. Daily stool samples, painful/stressful experiences, feeding patterns, and other clinical and demographic data were collected. Gut microbiota was profiled using 16S rRNA sequencing, and operational taxonomic units (OTUs) were selected to predict the neurobehaviors. The neurobehavioral development was assessed by the Neonatal Neurobehavioral Scale (NNNS) at 36 to 38 weeks of post-menstrual age (PMA). Fifty-five infants who had NNNS measurements were included in the sparse log-contrast regression analysis. Results: Preterm infants who experienced a high level of pain/stress during the NICU hospitalization had higher NNNS stress/abstinence scores. Eight operational taxonomic units (OTUs) were identified to be associated with NNNS subscales after controlling demographic and clinical features, feeding patterns, and painful/stressful experiences. These OTUs and taxa belonging to seven genera, i.e., Enterobacteriaceae_unclassified, Escherichia-Shigella, Incertae_Sedis, Veillonella, Enterococcus, Clostridium_sensu_stricto_1, and Streptococcus with five belonging to Firmicutes and two belonging to Proteobacteria phylum. The enriched abundance of Enterobacteriaceae_unclassified (OTU17) and Streptococcus (OTU28) were consistently associated with less optimal neurobehavioral outcomes. The other six OTUs were also associated with infant neurobehavioral responses depending on days at NICU stay. Conclusions: This study explored the dynamic impact of specific OTUs on neurobehavioral development in preterm infants after controlling for early life experiences, i.e., acute and chronic pain/stress and feeding in the NICU. The gut microbiota and acute pain/stressful experiences dynamically impact the neurobehavioral development in preterm infants during their NICU hospitalization.
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- 2023
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23. Loss-of-function variants in the schizophrenia risk gene SETD1A alter neuronal network activity in human neurons through the cAMP/PKA pathway
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Shan Wang, Jon-Ruben van Rhijn, Ibrahim Akkouh, Naoki Kogo, Nadine Maas, Anna Bleeck, Irene Santisteban Ortiz, Elly Lewerissa, Ka Man Wu, Chantal Schoenmaker, Srdjan Djurovic, Hans van Bokhoven, Tjitske Kleefstra, Nael Nadif Kasri, and Dirk Schubert
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CP: Neuroscience ,Biology (General) ,QH301-705.5 - Abstract
Summary: Heterozygous loss-of-function (LoF) mutations in SETD1A, which encodes a subunit of histone H3 lysine 4 methyltransferase, cause a neurodevelopmental syndrome and increase the risk for schizophrenia. Using CRISPR-Cas9, we generate excitatory/inhibitory neuronal networks from human induced pluripotent stem cells with a SETD1A heterozygous LoF mutation (SETD1A+/−). Our data show that SETD1A haploinsufficiency results in morphologically increased dendritic complexity and functionally increased bursting activity. This network phenotype is primarily driven by SETD1A haploinsufficiency in glutamatergic neurons. In accordance with the functional changes, transcriptomic profiling reveals perturbations in gene sets associated with glutamatergic synaptic function. At the molecular level, we identify specific changes in the cyclic AMP (cAMP)/Protein Kinase A pathway pointing toward a hyperactive cAMP pathway in SETD1A+/− neurons. Finally, by pharmacologically targeting the cAMP pathway, we are able to rescue the network deficits in SETD1A+/− cultures. Our results demonstrate a link between SETD1A and the cAMP-dependent pathway in human neurons.
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- 2022
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24. Fungal-Bacterial Interactions in the Human Gut of Healthy Individuals
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Evy Maas, John Penders, and Koen Venema
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fungi ,microbiome ,ITS2 sequencing ,fungal-bacterial interactions ,Biology (General) ,QH301-705.5 - Abstract
Most studies of the microbiota in the human gut focus on the bacterial part, but increasing information shows that intestinal fungi are also important for maintaining health. This can be either by directly influencing the host or by indirectly influencing the gut bacteria that link to host health. Studies of fungal communities in large cohorts are scarce; therefore, this study aims at obtaining more insight into the mycobiome of healthy individuals and how this mycobiome interacts with the bacterial component of the microbiome. For this purpose, ITS2 and 16S rRNA gene amplicon sequencing was performed on fecal samples from 163 individuals which were available from two separate studies to analyze the fungal and bacterial microbiome, respectively, as well as the cross-kingdom interactions. The results showed a much lower fungal, as compared to bacterial, diversity. Ascomycota and Basidiomycota were the dominant fungal phyla across all the samples, but levels varied enormously between individuals. The ten most abundant fungal genera were Saccharomyces, Candida, Dipodascus, Aureobasidium, Penicillium, Hanseniaspora, Agaricus, Debaryomyces, Aspergillus, and Pichia, and here also extensive inter-individual variation was observed. Correlations were made between bacteria and fungi, and only positive correlations were observed. One of the correlations was between Malassezia restricta and the genus Bacteroides, which have both been previously described as alleviated in IBD. Most of the other correlations found were with fungi that are not known as gut colonizers but originate from food and the environment. To further investigate the importance of the observed correlations found, more research is needed to discriminate between gut colonizers and transient species.
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- 2023
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25. Studying Fungal-Bacterial Relationships in the Human Gut Using an In Vitro Model (TIM-2)
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Evy Maas, John Penders, and Koen Venema
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gut microbiota ,fungi ,bacteria ,in vitro model ,cross-kingdom relations ,Biology (General) ,QH301-705.5 - Abstract
The complex microbial community found in the human gut consist of members of multiple kingdoms, among which are bacteria and fungi. Microbiome research mainly focuses on the bacterial part of the microbiota, thereby neglecting interactions that can take place between bacteria and fungi. With the rise of sequencing techniques, the possibilities to study cross-kingdom relationships has expanded. In this study, fungal-bacterial relationships were investigated using the complex, dynamic computer-controlled in vitro model of the colon (TIM-2). Interactions were investigated by disruption of either the bacterial or fungal community by the addition of antibiotics or antifungals to TIM-2, respectively, compared to a control without antimicrobials. The microbial community was analyzed with the use of next generation sequencing of the ITS2 region and the 16S rRNA. Moreover, the production of SCFAs was followed during the interventions. Correlations between fungi and bacteria were calculated to investigate possible cross-kingdom interactions. The experiments showed that no significant differences in alpha-diversity were observed between the treatments with antibiotics and fungicide. For beta-diversity, it could be observed that samples treated with antibiotics clustered together, whereas the samples from the other treatments were more different. Taxonomic classification was done for both bacteria and fungi, but no big shifts were observed after treatments. At the level of individual genera, bacterial genus Akkermansia was shown to be increased after fungicide treatment. SCFAs levels were lowered in samples treated with antifungals. Spearman correlations suggested that cross-kingdom interactions are present in the human gut, and that fungi and bacteria can influence each other. Further research is required to gain more insights in these interactions and their molecular nature and to determine the clinical relevance.
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- 2023
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26. Modelling the Gut Fungal-Community in TIM-2 with a Microbiota from Healthy Individuals
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Evy Maas, John Penders, and Koen Venema
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fungi ,gut microbiota ,in vitro colon-model ,ITS2 sequencing ,dietary intervention ,Biology (General) ,QH301-705.5 - Abstract
Most research on the human microbiome focuses on the bacterial component, and this has led to a lack of information about the fungal component (mycobiota) and how this can influence human health, e.g., by modulation through the diet. The validated, dynamic computer-controlled model of the colon (TIM-2) is an in vitro model to study the microbiome and how this is influenced by interventions such as diet. In this study, it was used to the study the gut fungal-community. This was done in combination with next-generation sequencing of the ITS2 region for fungi and 16S rRNA for bacteria. Different dietary interventions (control diet (SIEM), high-carbohydrate, high-protein, glucose as a carbon source) were performed, to see if diet could shape the mycobiome. The mycobiome was investigated after the adaptation period, and throughout the intervention period which lasted 72 h, and samples were taken every 24 h. The fungal community showed low diversity and a greater variability when compared to bacteria. The mycobiome was affected most in the first hours of the adaptation period. Taxonomic classification showed that at the phylum-level Ascomycota and Basidiomycota dominated, while Agaricus, Aspergillus, Candida, Penicillum, Malassezia, Saccharomyces, Aureobasidium, Mycosphaerella, Mucor and Clavispora were the most abundant genera. During the intervention period, it was shown that the change of diet could influence the diversity. Clustering of samples for different time points was analyzed using Bray–Curtis dissimilarities. Samples of t0 clustered together, and samples of all other time points clustered together. The Bray–Curtis-dissimilarity analysis also showed that for the different dietary interventions, samples treated with glucose clustered together and were different from the other groups (p < 0.05, PERMANOVA). Taxonomic classification showed that the genera Alternaria, Thanatephorus, Candida and Dekkera differentially changed for the various diet groups (p < 0.05, Kruskal–Wallis). These results show that the mycobiota could be modelled in TIM-2; however, the low diversity and high variability make studying fungal, as compared to bacterial, communities, much more challenging. Future research should focus on the optimization of the stability of the fungal community to increase the strength of the results.
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- 2023
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27. Occurrence of Rickettsia spp., Hantaviridae, Bartonella spp. and Leptospira spp. in European Moles (Talpa europaea) from the Netherlands
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Tryntsje Cuperus, Ankje de Vries, Ryanne I. Jaarsma, Hein Sprong, and Miriam Maas
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Talpa europaea ,mole ,zoonotic pathogens ,zoonoses ,epidemiology ,Biology (General) ,QH301-705.5 - Abstract
The European mole (Talpa europaea) has a widespread distribution throughout Europe. However, little is known about the presence of zoonotic pathogens in European moles. We therefore tested 180 moles from the middle and the south of the Netherlands by (q)PCR for the presence of multiple (tick-borne) zoonotic pathogens. Spotted fever Rickettsia was found in one (0.6%), Leptospira spp. in three (1.7%), Bartonella spp. in 69 (38.3%) and Hantaviridae in 89 (49.4%) of the 180 moles. Infections with Anaplasma phagocytophilum, Babesia spp., Neoehrlichia mikurensis, Borrelia spp., Spiroplasma spp. and Francisella tularensis were not found. In addition, in a subset of 35 moles no antibodies against Tick-borne encephalitis virus were found. The obtained sequences of Bartonella spp. were closely related to Bartonella spp. sequences from moles in Spain and Hungary. The Hantaviridae were identified as the mole-borne Nova virus, with high sequence similarity to sequences from other European countries, and Bruges virus. Though the zoonotic risk from moles appears limited, our results indicate that these animals do play a role in multiple host-pathogen cycles.
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- 2022
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28. Primary Focal Segmental Glomerulosclerosis Plasmas Increase Lipid Droplet Formation and Perilipin-2 Expression in Human Podocytes
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Dirk J. W. den Braanker, Rutger J. H. Maas, Guido van Mierlo, Naomi M. J. Parr, Marinka Bakker-van Bebber, Jeroen K. J. Deegens, Pascal W. T. C. Jansen, Jolein Gloerich, Brigith Willemsen, Henry B. Dijkman, Alain J. van Gool, Jack F. M. Wetzels, Markus M. Rinschen, Michiel Vermeulen, Tom Nijenhuis, and Johan van der Vlag
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circulating permeability factor ,primary focal segmental glomerulosclerosis (FSGS) ,lipid droplets ,podocytes ,perilipin-2 ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Many patients with primary focal segmental glomerulosclerosis (FSGS) develop recurrence of proteinuria after kidney transplantation. Several circulating permeability factors (CPFs) responsible for recurrence have been suggested, but were never validated. We aimed to find proteins involved in the mechanism of action of CPF(s) and/or potential biomarkers for the presence of CPF(s). Cultured human podocytes were exposed to plasma from patients with FSGS with presumed CPF(s) or healthy and disease controls. Podocyte proteomes were analyzed by LC–MS. Results were validated using flow cytometry, RT-PCR, and immunofluorescence. Podocyte granularity was examined using flow cytometry, electron microscopy imaging, and BODIPY staining. Perilipin-2 protein expression was increased in podocytes exposed to presumed CPF-containing plasmas, and correlated with the capacity of plasma to induce podocyte granularity, identified as lipid droplet accumulation. Elevated podocyte perilipin-2 was confirmed at protein and mRNA level and was also detected in glomeruli of FSGS patients whose active disease plasmas induced podocyte perilipin-2 and lipid droplets. Our study demonstrates that presumably, CPF-containing plasmas from FSGS patients induce podocyte lipid droplet accumulation and perilipin-2 expression, identifying perilipin-2 as a potential biomarker. Future research should address the mechanism underlying CPF-induced alterations in podocyte lipid metabolism, which ultimately may result in novel leads for treatment.
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- 2022
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29. iRODS metadata management for a cancer genome analysis workflow
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Lech Nieroda, Lukas Maas, Scott Thiebes, Ulrich Lang, Ali Sunyaev, Viktor Achter, and Martin Peifer
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Next generation sequencing (NGS) ,Genome analysis ,iRODS ,Workflow integration ,High performance computing (HPC) ,Data security ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Biology (General) ,QH301-705.5 - Abstract
Abstract Background The massive amounts of data from next generation sequencing (NGS) methods pose various challenges with respect to data security, storage and metadata management. While there is a broad range of data analysis pipelines, these challenges remain largely unaddressed to date. Results We describe the integration of the open-source metadata management system iRODS (Integrated Rule-Oriented Data System) with a cancer genome analysis pipeline in a high performance computing environment. The system allows for customized metadata attributes as well as fine-grained protection rules and is augmented by a user-friendly front-end for metadata input. This results in a robust, efficient end-to-end workflow under consideration of data security, central storage and unified metadata information. Conclusions Integrating iRODS with an NGS data analysis pipeline is a suitable method for addressing the challenges of data security, storage and metadata management in NGS environments.
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- 2019
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30. DNA Methylation Signature for JARID2-Neurodevelopmental Syndrome
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Eline A. Verberne, Liselot van der Laan, Sadegheh Haghshenas, Kathleen Rooney, Michael A. Levy, Mariëlle Alders, Saskia M. Maas, Sandra Jansen, Agne Lieden, Britt-Marie Anderlid, Louise Rafael-Croes, Philippe M. Campeau, Ayeshah Chaudhry, David A. Koolen, Rolph Pfundt, Anna C. E. Hurst, Frederic Tran-Mau-Them, Ange-Line Bruel, Laetitia Lambert, Bertrand Isidor, Marcel M. A. M. Mannens, Bekim Sadikovic, Peter Henneman, and Mieke M. van Haelst
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JARID2 ,developmental disorder ,DNA methylation ,epigenetics ,episignature ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
JARID2 (Jumonji, AT Rich Interactive Domain 2) pathogenic variants cause a neurodevelopmental syndrome, that is characterized by developmental delay, cognitive impairment, hypotonia, autistic features, behavior abnormalities and dysmorphic facial features. JARID2 encodes a transcriptional repressor protein that regulates the activity of various histone methyltransferase complexes. However, the molecular etiology is not fully understood, and JARID2-neurodevelopmental syndrome may vary in its typical clinical phenotype. In addition, the detection of variants of uncertain significance (VUSs) often results in a delay of final diagnosis which could hamper the appropriate care. In this study we aim to detect a specific and sensitive DNA methylation signature for JARID2-neurodevelopmental syndrome. Peripheral blood DNA methylation profiles from 56 control subjects, 8 patients with (likely) pathogenic JARID2 variants and 3 patients with JARID2 VUSs were analyzed. DNA methylation analysis indicated a clear and robust separation between patients with (likely) pathogenic variants and controls. A binary model capable of classifying patients with the JARID2-neurodevelopmental syndrome was constructed on the basis of the identified episignature. Patients carrying VUSs clustered with the control group. We identified a distinct DNA methylation signature associated with JARID2-neurodevelopmental syndrome, establishing its utility as a biomarker for this syndrome and expanding the EpiSign diagnostic test.
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- 2022
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31. Cognitive Diagnostic Assessment in University Statistics Education: Valid and Reliable Skill Measurement for Actionable Feedback Using Learning Dashboards
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Lientje Maas, Matthieu J. S. Brinkhuis, Liesbeth Kester, and Leoniek Wijngaards-de Meij
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online formative assessment ,cognitive modeling ,skill measurement ,validation ,reliability ,learning dashboards ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
E-learning is increasingly used to support student learning in higher education, facilitating administration of online formative assessments. Although providing diagnostic, actionable feedback is generally more effective, in current practice, feedback is often given in the form of a simple proportion of correctly solved items. This study shows the validation process of constructing detailed diagnostic information on a set of skills, abilities, and cognitive processes (so-called attributes) from students’ item response data with diagnostic classification models. Attribute measurement in the domain of statistics education is validated based on both expert judgment and empirical student data from a think-aloud study and large-scale assessment administration. The constructed assessments provide a valid and reliable measurement of the attributes. Inferences that can be drawn from the results of these formative assessments are discussed and it is demonstrated how this information can be communicated to students via learning dashboards to allow them to make more effective learning choices.
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- 2022
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32. MicroRNA-26b Attenuates Platelet Adhesion and Aggregation in Mice
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Linsey J. F. Peters, Constance C. F. M. J. Baaten, Sanne L. Maas, Chang Lu, Magdolna Nagy, Natalie J. Jooss, Kiril Bidzhekov, Donato Santovito, Daniel Moreno-Andrés, Joachim Jankowski, Erik A. L. Biessen, Yvonne Döring, Johan W. M. Heemskerk, Christian Weber, Marijke J. E. Kuijpers, and Emiel P. C. van der Vorst
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thrombosis ,platelets ,microRNAs ,microRNA-26b ,cardiovascular diseases ,Biology (General) ,QH301-705.5 - Abstract
Platelets are key regulators of haemostasis, making platelet dysfunction a major driver of thrombosis. Numerous processes that determine platelet function are influenced by microRNAs (miRs). MiR-26b is one of the highest-expressed miRs in healthy platelets, and its expression in platelets is changed in a diseased state. However, the exact effect of this miR on platelet function has not been studied yet. In this study, we made use of a whole-body knockout of miR-26b in ApoE-deficient mice in order to determine its impact on platelet function, thrombus formation and platelet signalling both ex vivo and in vivo. We show that a whole-body deficiency of miR-26b exacerbated platelet adhesion and aggregation ex vivo. Additionally, in vivo, platelets adhered faster, and larger thrombi were formed in mice lacking miR-26b. Moreover, isolated platelets from miR-26b-deficient mice showed a hyperactivated Src and EGFR signalling. Taken together, we show here for the first time that miR-26b attenuates platelet adhesion and aggregation, possibly through Src and EGFR signalling.
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- 2022
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33. Model-Based Analysis of Different Equivalent Consumption Minimization Strategies for a Plug-In Hybrid Electric Vehicle
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Stefan Geng, Thomas Schulte, and Jürgen Maas
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PHEV ,ECMS ,multimode transmission ,optimization ,powertrain modeling ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Plug-in hybrid electric vehicles (PHEVs) are developed to reduce fuel consumption and the emission of carbon dioxide. Common powertrain configurations of PHEVs (i.e., the configuration of the combustion engine, electric motor, and transmission) can be operated either in series, parallel, or power split hybrid mode, whereas powertrain configurations with multimode transmissions enable switching between those modes during vehicle operation. Hence, depending on the current operation state of the vehicle, the most appropriate mode in terms efficiency can be selected. This, however, requires an operating strategy, which controls the mode selection as well as the torque distribution between the combustion engine and electric motor with the aim of optimal battery depletion and minimal fuel consumption. A well-known approach is the equivalent consumption minimization strategy (ECMS). It can be applied by using optimizations based on a prediction of the future driving behavior. Since the outcome of the ECMS depends on the quality of this prediction, it is crucial to know how accurate the predictions must be in order to obtain acceptable results. In this contribution, various prediction methods and real-time capable ECMS implementations are analyzed and compared in terms of the achievable fuel economy. The basis for the analysis is a holistic model of a state-of-the-art PHEV powertrain configuration, comprising the multimode transmission, corresponding powertrain components, and representative real-world driving data.
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- 2022
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34. Versatile Role of Rab27a in Glioma: Effects on Release of Extracellular Vesicles, Cell Viability, and Tumor Progression
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Thomas S. van Solinge, Erik R. Abels, Lieke L. van de Haar, Killian S. Hanlon, Sybren L. N. Maas, Rosalie Schnoor, Jeroen de Vrij, Xandra O. Breakefield, and Marike L. D. Broekman
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glioma ,glioblastoma ,extracellular vesicles ,exosomes ,tumor microenvironment ,Rab27a ,Biology (General) ,QH301-705.5 - Abstract
Introduction: Glioma cells exert influence over the tumor-microenvironment in part through the release of extracellular vesicles (EVs), membrane-enclosed structures containing proteins, lipids, and RNAs. In this study, we evaluated the function of Ras-associated protein 27a (Rab27a) in glioma and evaluated the feasibility of assessing its role in EV release in glioma cells in vitro and in vivo.Methods: Rab27a was knocked down via a short hairpin RNA (shRNA) stably expressed in mouse glioma cell line GL261, with a scrambled shRNA as control. EVs were isolated by ultracentrifugation and quantified with Nanoparticle Tracking Analysis (NTA) and Tunable Resistive Pulse Sensing (TRPS). CellTiter-Glo viability assays and cytokine arrays were used to evaluate the impact of Rab27a knockdown. GL261.shRab27a cells and GL261.shControl were implanted into the left striatum of eight mice to assess tumor growth and changes in the tumor microenvironment.Results: Knockdown of Rab27a in GL261 glioma cells decreased the release of small EVs isolated at 100,000 × g in vitro (p = 0.005), but not the release of larger EVs, isolated at 10,000 × g. GL261.shRab27a cells were less viable compared to the scramble control in vitro (p < 0.005). A significant increase in CCL2 expression in shRab27a GL261 cells was also observed (p < 0.001). However, in vivo there was no difference in tumor growth or overall survival between the two groups, while shRab27a tumors showed lower proliferation at the tumor borders. Decreased infiltration of IBA1 positive macrophages and microglia, but not FoxP3 positive regulatory T cells was observed.Conclusion: Rab27a plays an important role in the release of small EVs from glioma cells, and also in their viability and expression of CCL2 in vitro. As interference in Rab27a expression influences glioma cell viability and expression profiles, future studies should be cautious in using the knockdown of Rab27a as a means of studying the role of small EVs in glioma growth.
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- 2020
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35. Gradients in the mammalian cerebellar cortex enable Fourier-like transformation and improve storing capacity
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Isabelle Straub, Laurens Witter, Abdelmoneim Eshra, Miriam Hoidis, Niklas Byczkowicz, Sebastian Maas, Igor Delvendahl, Kevin Dorgans, Elise Savier, Ingo Bechmann, Martin Krueger, Philippe Isope, and Stefan Hallermann
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electrophysiology ,cerebellum ,granule cell ,mossy fiber ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Cerebellar granule cells (GCs) make up the majority of all neurons in the vertebrate brain, but heterogeneities among GCs and potential functional consequences are poorly understood. Here, we identified unexpected gradients in the biophysical properties of GCs in mice. GCs closer to the white matter (inner-zone GCs) had higher firing thresholds and could sustain firing with larger current inputs than GCs closer to the Purkinje cell layer (outer-zone GCs). Dynamic Clamp experiments showed that inner- and outer-zone GCs preferentially respond to high- and low-frequency mossy fiber inputs, respectively, enabling dispersion of the mossy fiber input into its frequency components as performed by a Fourier transformation. Furthermore, inner-zone GCs have faster axonal conduction velocity and elicit faster synaptic potentials in Purkinje cells. Neuronal network modeling revealed that these gradients improve spike-timing precision of Purkinje cells and decrease the number of GCs required to learn spike-sequences. Thus, our study uncovers biophysical gradients in the cerebellar cortex enabling a Fourier-like transformation of mossy fiber inputs.
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- 2020
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36. Extracellular Matrix Composition and Remodeling: Current Perspectives on Secondary Palate Formation, Cleft Lip/Palate, and Palatal Reconstruction
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Katiúcia Batista Silva Paiva, Clara Soeiro Maas, Pâmella Monique dos Santos, José Mauro Granjeiro, and Ariadne Letra
- Subjects
palatogenesis ,extracellular matrix ,extracellular matrix remodeling ,metalloproteinases ,cleft lip/palate ,palatal reconstruction ,Biology (General) ,QH301-705.5 - Abstract
Craniofacial development comprises a complex process in humans in which failures or disturbances frequently lead to congenital anomalies. Cleft lip with/without palate (CL/P) is a common congenital anomaly that occurs due to variations in craniofacial development genes, and may occur as part of a syndrome, or more commonly in isolated forms (non-syndromic). The etiology of CL/P is multifactorial with genes, environmental factors, and their potential interactions contributing to the condition. Rehabilitation of CL/P patients requires a multidisciplinary team to perform the multiple surgical, dental, and psychological interventions required throughout the patient’s life. Despite progress, lip/palatal reconstruction is still a major treatment challenge. Genetic mutations and polymorphisms in several genes, including extracellular matrix (ECM) genes, soluble factors, and enzymes responsible for ECM remodeling (e.g., metalloproteinases), have been suggested to play a role in the etiology of CL/P; hence, these may be considered likely targets for the development of new preventive and/or therapeutic strategies. In this context, investigations are being conducted on new therapeutic approaches based on tissue bioengineering, associating stem cells with biomaterials, signaling molecules, and innovative technologies. In this review, we discuss the role of genes involved in ECM composition and remodeling during secondary palate formation and pathogenesis and genetic etiology of CL/P. We also discuss potential therapeutic approaches using bioactive molecules and principles of tissue bioengineering for state-of-the-art CL/P repair and palatal reconstruction.
- Published
- 2019
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37. Towards a New, Pre-Clinical, Subject-Independent Test Model for Kinematic Analysis after Total Knee Arthroplasty—Influence of the Proximo-Distal Patella Position and Patellar Tendon Stiffness
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Adrian Sauer, Allan Maas, Svenja Ottawa, Alexander Giurea, and Thomas M. Grupp
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dynamic finite element model ,knee kinematics ,patellofemoral kinematics ,pre-clinical testing ,total knee arthroplasty ,patellar tendon ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Although simulation models are heavily used in biomechanical research and testing of TKA implants, pre-clinical tools for a holistic estimation of implant performance under dynamic loading conditions are rare. The objective of this study was the development of an efficient pre-clinical test method for analyzing knee contact mechanics and kinematics based on a dynamic FE model and to evaluate the effects of the proximo-distal patella position and the patellar tendon stiffness on the patellar kinematics. A finite element-based workflow for knee prostheses designs was developed based on standardized in vivo load data, which included the tibial forces and moments. In a new research approach, the tibial forces are used as input for the model, whereas the tibial moments were used to validate the results. For the standardized sit down, stand up, and knee bend load cycles, the calculated tibial moments show only small deviations from the reference values—especially for high flexion angles. For the knee bend cycle, the maximum absolute value of patellar flexion decreases for higher patellar tendon stiffness and more distally placed patellar components. Therefore, patella-related clinical problems caused by patella baja may also arise if the patellar tendon is too weak for high tibiofemoral flexion angles.
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- 2021
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38. Perinatal High-Fat Diet Influences Ozone-Induced Responses on Pulmonary Oxidant Status and the Molecular Control of Mitophagy in Female Rat Offspring
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Sven H. Rouschop, Samantha J. Snow, Urmila P. Kodavanti, Marie-José Drittij, Lou M. Maas, Antoon Opperhuizen, Frederik J. van Schooten, Alexander H. Remels, and Roger W. Godschalk
- Subjects
high-fat diet ,obesity ,perinatal ,ozone ,pulmonary toxicity ,mitochondria ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Previous research has shown that a perinatal obesogenic, high-fat diet (HFD) is able to exacerbate ozone-induced adverse effects on lung function, injury, and inflammation in offspring, and it has been suggested that mitochondrial dysfunction is implicated herein. The aim of this study was to investigate whether a perinatal obesogenic HFD affects ozone-induced changes in offspring pulmonary oxidant status and the molecular control of mitochondrial function. For this purpose, female Long-Evans rats were fed a control diet or HFD before and during gestation, and during lactation, after which the offspring were acutely exposed to filtered air or ozone at a young-adult age (forty days). Directly following this exposure, the offspring lungs were examined for markers related to oxidative stress; oxidative phosphorylation; and mitochondrial fusion, fission, biogenesis, and mitophagy. Acute ozone exposure significantly increased pulmonary oxidant status and upregulated the molecular machinery that controls receptor-mediated mitophagy. In female offspring, a perinatal HFD exacerbated these responses, whereas in male offspring, responses were similar for both diet groups. The expression of the genes and proteins involved in oxidative phosphorylation and mitochondrial biogenesis, fusion, and fission was not affected by ozone exposure or perinatal HFD. These findings suggest that a perinatal HFD influences ozone-induced responses on pulmonary oxidant status and the molecular control of mitophagy in female rat offspring.
- Published
- 2021
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39. Selective Phosphorylation of Akt/Protein-Kinase B Isoforms in Response to Dietary Cues
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Laura Christin Trautenberg, Elodie Prince, Cornelia Maas, Nora Beier, Freya Honold, Michal Grzybek, and Marko Brankatschk
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Drosophila ,Saccharomyces cerevisiae ,Cystobasidium oligophagum ,Akt ,PKB ,Akt phosphorylation ,Biology (General) ,QH301-705.5 - Abstract
A calorie-rich diet is one reason for the continuous spread of metabolic syndromes in western societies. Smart food design is one powerful tool to prevent metabolic stress, and the search for suitable bioactive additives is a continuous task. The nutrient-sensing insulin pathway is an evolutionary conserved mechanism that plays an important role in metabolism, growth and development. Recently, lipid cues capable to stimulate insulin signaling were identified. However, the mechanistic base of their activity remains obscure to date. We show that specific Akt/Protein-kinase B isoforms are responsive to different calorie-rich diets, and potentiate the activity of the cellular insulin cascade. Our data add a new dimension to existing models and position Drosophila as a powerful tool to study the relation between dietary lipid cues and the insulin-induced cellular signal pathway.
- Published
- 2019
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40. Glioblastoma-Associated Microglia Reprogramming Is Mediated by Functional Transfer of Extracellular miR-21
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Erik R. Abels, Sybren L.N. Maas, Lisa Nieland, Zhiyun Wei, Pike See Cheah, Eric Tai, Christy-Joy Kolsteeg, Sophie A. Dusoswa, David T. Ting, Suzanne Hickman, Joseph El Khoury, Anna M. Krichevsky, Marike L.D. Broekman, and Xandra O. Breakefield
- Subjects
Biology (General) ,QH301-705.5 - Abstract
Summary: Gliomas are primary, diffusely infiltrating brain tumors. Microglia are innate immune cells in the CNS and make up a substantial portion of the tumor mass. Glioma cells shape their microenvironment, communicating with and reprogramming surrounding cells, resulting in enhanced angiogenesis, immune suppression, and remodeling of the extracellular matrix. Glioma cells communicate with microglia, in part by releasing extracellular vesicles (EVs). Mouse glioma cells stably expressing a palmitoylated GFP to label EVs were implanted intracranially into syngeneic miR-21-null mice. Here, we demonstrate functional delivery of miR-21, regulating specific downstream mRNA targets in microglia after uptake of tumor-derived EVs. These findings attest to EV-dependent microRNA delivery as studied in an in vivo-based model and provide insight into the reprograming of microglial cells by tumor cells to create a favorable microenvironment for cancer progression. : Abels et al. show miR-21 transfer from glioma to microglia by palmitoylated GFP-labeled extracellular vesicles in vivo. This transfer results in miR-21 target-specific mRNA downregulation. Following downregulation of Btg2, proliferation in microglia is increased, suggesting reprogramming of microglia in the tumor microenvironment through extracellular vesicles shed by glioma cells.
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- 2019
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41. HSF2BP Interacts with a Conserved Domain of BRCA2 and Is Required for Mouse Spermatogenesis
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Inger Brandsma, Koichi Sato, Sari E. van Rossum-Fikkert, Nicole van Vliet, Esther Sleddens, Marcel Reuter, Hanny Odijk, Nathalie van den Tempel, Dick H.W. Dekkers, Karel Bezstarosti, Jeroen A.A. Demmers, Alex Maas, Joyce Lebbink, Claire Wyman, Jeroen Essers, Dik C. van Gent, Willy M. Baarends, Puck Knipscheer, Roland Kanaar, and Alex N. Zelensky
- Subjects
Biology (General) ,QH301-705.5 - Abstract
Summary: The tumor suppressor BRCA2 is essential for homologous recombination (HR), replication fork stability, and DNA interstrand crosslink repair in vertebrates. We identify HSF2BP, a protein previously described as testis specific and not characterized functionally, as an interactor of BRCA2 in mouse embryonic stem cells, where the 2 proteins form a constitutive complex. HSF2BP is transcribed in all cultured human cancer cell lines tested and elevated in some tumor samples. Inactivation of the mouse Hsf2bp gene results in male infertility due to a severe HR defect during spermatogenesis. The BRCA2-HSF2BP interaction is highly evolutionarily conserved and maps to armadillo repeats in HSF2BP and a 68-amino acid region between the BRC repeats and the DNA binding domain of human BRCA2 (Gly2270-Thr2337) encoded by exons 12 and 13. This region of BRCA2 does not harbor known cancer-associated missense mutations and may be involved in the reproductive rather than the tumor-suppressing function of BRCA2. : BRCA2 is a key homologous recombination mediator in vertebrates. Brandsma et al. show that it directly interacts with a testis-expressed protein, HSF2BP, and that male mice deficient for HSF2BP are infertile due to a meiotic recombination defect. They also find that HSF2BP contributes to DNA repair in mouse embryonic stem cells. Keywords: HSF2BP, BRCA2, homologous recombination, meiosis, spermatogenesis
- Published
- 2019
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42. Candida albicans induces mucosal bacterial dysbiosis that promotes invasive infection.
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Martinna Bertolini, Amit Ranjan, Angela Thompson, Patricia I Diaz, Takanori Sobue, Kendra Maas, and Anna Dongari-Bagtzoglou
- Subjects
Immunologic diseases. Allergy ,RC581-607 ,Biology (General) ,QH301-705.5 - Abstract
Infectious complications are a common cause of morbidity and mortality in cancer patients undergoing chemotherapy due to increased risk of oral and gastrointestinal candidiasis, candidemia and septicemia. Interactions between C. albicans and endogenous mucosal bacteria are important in understanding the mechanisms of invasive infection. We published a mouse intravenous chemotherapy model that recapitulates oral and intestinal mucositis, and myelosuppression in patients receiving 5-fluorouracil. We used this model to study the influence of C. albicans on the mucosal bacterial microbiome and compared global community changes in the oral and intestinal mucosa of the same mice. We validated 16S rRNA gene sequencing data by qPCR, in situ hybridization and culture approaches. Mice receiving both 5Fu and C. albicans had an endogenous bacterial overgrowth on the oral but not the small intestinal mucosa. C. albicans infection was associated with loss of mucosal bacterial diversity in both sites with indigenous Stenotrophomonas, Alphaproteobacteria and Enterococcus species dominating the small intestinal, and Enterococcus species dominating the oral mucosa. Both immunosuppression and Candida infection contributed to changes in the oral microbiota. Enterococci isolated from mice with oropharyngeal candidiasis were implicated in degrading the epithelial junction protein E-cadherin and increasing the permeability of the oral epithelial barrier in vitro. Importantly, depletion of these organisms with antibiotics in vivo attenuated oral mucosal E-cadherin degradation and C. albicans invasion without affecting fungal burdens, indicating that bacterial community changes represent overt dysbiosis. Our studies demonstrate a complex interaction between C. albicans, the resident mucosal bacterial microbiota and the host environment in pathogenesis. We shed significant new light on the role of C. albicans in shaping resident bacterial communities and driving mucosal dysbiosis.
- Published
- 2019
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43. Control of Drosophila Growth and Survival by the Lipid Droplet-Associated Protein CG9186/Sturkopf
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Michael Werthebach, Fiona A. Stewart, Alisa Gahlen, Tabea Mettler-Altmann, Irfan Akhtar, Kerstin Maas-Enriquez, Andrea Droste, Thomas O. Eichmann, Gereon Poschmann, Kai Stühler, and Mathias Beller
- Subjects
Biology (General) ,QH301-705.5 - Abstract
Summary: Lipid droplets (LDs) are the universal cellular storage organelles for esterified neutral lipids. The increasing number of characterized LD-associated proteins attained LDs with hitherto unexpected functions on top of their classical role as energy depot. Here, we characterize the LD-associated protein CG9186 of Drosophila by a CRISPR/Cas9-derived mutant fly line. While the mutant flies only showed a mild triacylglycerol storage phenotype, they were highly protected from desiccation stress, likely linked to a reduced locomotor activity and altered cuticular hydrocarbons. Both parameters depend on juvenile hormone (JH) signaling. Together with an observed interaction between CG9186 and JH-degrading enzymes, our results suggest that CG9186 participates in endocrine physiology regulation. In support of this hypothesis, CG9186 mutant flies show an altered expression of JH target genes and fail to adjust their developmental rate to dietary yeast-to-sugar ratio changes. Our results thus link LDs to organismic physiology regulation. : Werthebach et al. introduce the lipid droplet-associated protein CG9186/sturkopf as a component of organismic physiology regulation, which affects insulin and juvenile hormone signaling activity. Keywords: lipid droplets, physiology, Drosophila, larval developmental rate, nutrient sensing, juvenile hormone, LDAH, c2orf43, desiccation, insulin signaling
- Published
- 2019
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44. Age-Dependent Control of Collagen-Dependent Platelet Responses by Thrombospondin-1—Comparative Analysis of Platelets from Neonates, Children, Adolescents, and Adults
- Author
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Katrin Herken, Martin Glauner, Stefanie C. Robert, Matthias Maas, Sonja Zippel, Ulrike Nowak-Göttl, Barbara Zieger, Judith Lahav, Anke C. Fender, Kerstin Jurk, and Beate E. Kehrel
- Subjects
neonates ,platelets ,collagen ,thrombospondin-1 ,flow cytometry ,reference ranges ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Platelet function is developmentally regulated. Healthy neonates do not spontaneously bleed, but their platelets are hypo-reactive to several agonists. The mechanisms underlying immature platelet function in neonates are incompletely understood. This critical issue remains challenging for the establishment of age-specific reference ranges. In this study, we evaluated platelet reactivity of five pediatric age categories, ranging from healthy full-term neonates up to adolescents (11–18 years) in comparison to healthy adults (>18 years) by flow cytometry. We confirmed that platelet hypo-reactivity detected by fibrinogen binding, P-selectin, and CD63 surface expression was most pronounced in neonates compared to other pediatric age groups. However, maturation of platelet responsiveness varied with age, agonist, and activation marker. In contrast to TRAP and ADP, collagen-induced platelet activation was nearly absent in neonates. Granule secretion markedly remained impaired at least up to 10 years of age compared to adults. We show for the first time that neonatal platelets are deficient in thrombospondin-1, and exogenous platelet-derived thrombospondin-1 allows platelet responsiveness to collagen. Platelets from all pediatric age groups normally responded to the C-terminal thrombospondin-1 peptide RFYVVMWK. Thus, thrombospondin-1 deficiency of neonatal platelets might contribute to the relatively impaired response to collagen, and platelet-derived thrombospondin-1 may control distinct collagen-induced platelet responses.
- Published
- 2021
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45. Comparative Analysis Identifies Similarities between the Human and Murine Microglial Sensomes
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Erik R. Abels, Lisa Nieland, Suzanne Hickman, Marike L. D. Broekman, Joseph El Khoury, and Sybren L. N. Maas
- Subjects
microglia ,RNAseq ,sensome ,aging ,gene expression ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
One of the essential functions of microglia is to continuously sense changes in their environment and adapt to those changes. For this purpose, they use a set of genes termed the sensome. This sensome is comprised of the most abundantly expressed receptors on the surface of microglia. In this study, we updated previously identified mouse microglial sensome by incorporating an additional published RNAseq dataset into the data-analysis pipeline. We also identified members of the human microglial sensome using two independent human microglia RNAseq data sources. Using both the mouse and human microglia sensomes, we identified a key set of genes conserved between the mouse and human microglial sensomes as well as some differences between the species. We found a key set of 57 genes to be conserved in both mouse and human microglial sensomes. We define these genes as the “microglia core sensome”. We then analyzed expression of genes in this core sensome in five different datasets from two neurodegenerative disease models at various stages of the diseases and found that, overall, changes in the level of expression of microglial sensome genes are specific to the disease or condition studied. Our results highlight the relevance of data generated in mice for understanding the biology of human microglia, but also stress the importance of species-specific gene sets for the investigation of diseases involving microglia. Defining this microglial specific core sensome may help identify pathological changes in microglia in humans and mouse models of human disease.
- Published
- 2021
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46. The Identification of Small Molecule Inhibitors That Reduce Invasion and Metastasis of Aggressive Cancers
- Author
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Arjanneke F. van de Merbel, Onno van Hooij, Geertje van der Horst, Cindy C. M. van Rijt-van de Westerlo, Maaike H. van der Mark, Henry Cheung, Jan Kroon, Gerald W. Verhaegh, Johan Tijhuis, Antoine Wellink, Peter Maas, Henk Viëtor, Jack A. Schalken, and Gabri van der Pluijm
- Subjects
small molecule inhibitors ,prostate cancer ,breast cancer ,bladder cancer ,metastasis ,invasiveness ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Transformed epithelial cells can activate programs of epithelial plasticity and switch from a sessile, epithelial phenotype to a motile, mesenchymal phenotype. This process is linked to the acquisition of an invasive phenotype and the formation of distant metastases. The development of compounds that block the acquisition of an invasive phenotype or revert the invasive mesenchymal phenotype into a more differentiated epithelial phenotype represent a promising anticancer strategy. In a high-throughput assay based on E-cadherin (re)induction and the inhibition of tumor cell invasion, 44,475 low molecular weight (LMW) compounds were screened. The screening resulted in the identification of candidate compounds from the PROAM02 class. Selected LMW compounds activated E-cadherin promoter activity and inhibited cancer cell invasion in multiple metastatic human cancer cell lines. The intraperitoneal administration of selected LMW compounds reduced the tumor burden in human prostate and breast cancer in vivo mouse models. Moreover, selected LMW compounds decreased the intra-bone growth of xenografted human prostate cancer cells. This study describes the identification of the PROAM02 class of small molecules that can be exploited to reduce cancer cell invasion and metastases. Further clinical evaluation of selected candidate inhibitors is warranted to address their safety, bioavailability and antitumor efficacy in the management of patients with aggressive cancers.
- Published
- 2021
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47. Trimethyllysine: From Carnitine Biosynthesis to Epigenetics
- Author
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Marijn N. Maas, Jordi C. J. Hintzen, Miriam R. B. Porzberg, and Jasmin Mecinović
- Subjects
trimethyllysine ,epigenetics ,post-translational modifications ,protein lysine methyltransferases ,protein lysine demethylases ,carnitine ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Trimethyllysine is an important post-translationally modified amino acid with functions in the carnitine biosynthesis and regulation of key epigenetic processes. Protein lysine methyltransferases and demethylases dynamically control protein lysine methylation, with each state of methylation changing the biophysical properties of lysine and the subsequent effect on protein function, in particular histone proteins and their central role in epigenetics. Epigenetic reader domain proteins can distinguish between different lysine methylation states and initiate downstream cellular processes upon recognition. Dysregulation of protein methylation is linked to various diseases, including cancer, inflammation, and genetic disorders. In this review, we cover biomolecular studies on the role of trimethyllysine in carnitine biosynthesis, different enzymatic reactions involved in the synthesis and removal of trimethyllysine, trimethyllysine recognition by reader proteins, and the role of trimethyllysine on the nucleosome assembly.
- Published
- 2020
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48. Daily cycle in oxygen consumption by the sea anemone Nematostella vectensis Stephenson
- Author
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Amy E. Maas, Ian T. Jones, Adam M. Reitzel, and Ann M. Tarrant
- Subjects
Circadian ,Cnidarian ,Respirometry ,Science ,Biology (General) ,QH301-705.5 - Abstract
In bilaterian animals, the circadian clock is intimately involved in regulating energetic metabolism. Although cnidarians exhibit diel behavioral rhythms including cycles in locomotor activity, tentacle extension and spawning, daily cycles in cnidarian metabolism have not been described. To explore a possible circadian metabolic cycle, we maintained the anemone Nematostella vectensis in a 12 h light/dark cycle, a reversed light cycle, or in constant darkness. Oxygen consumption rates were measured at intervals using an optical oxygen meter. Respiration rates responded to entrainment with higher rates during light periods. During a second experiment with higher temporal resolution, respiration rates peaked late in the light period. The diel pattern could be detected after six days in constant darkness. Together, our results suggest that respiration rates in Nematostella exhibit a daily cycle that may be under circadian control and that the cycle in respiration rate is not driven by the previously described nocturnal increase in locomotor activity in this species.
- Published
- 2016
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49. BMP-SMAD Signaling Regulates Lineage Priming, but Is Dispensable for Self-Renewal in Mouse Embryonic Stem Cells
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Maria Gomes Fernandes, Ruben Dries, Matthias S. Roost, Stefan Semrau, Ana de Melo Bernardo, Richard P. Davis, Ramprasad Ramakrishnan, Karoly Szuhai, Elke Maas, Lieve Umans, Vanesa Abon Escalona, Daniela Salvatori, Dieter Deforce, Wim Van Criekinge, Danny Huylebroeck, Christine Mummery, An Zwijsen, and Susana M. Chuva de Sousa Lopes
- Subjects
Medicine (General) ,R5-920 ,Biology (General) ,QH301-705.5 - Abstract
Naive mouse embryonic stem cells (mESCs) are in a metastable state and fluctuate between inner cell mass- and epiblast-like phenotypes. Here, we show transient activation of the BMP-SMAD signaling pathway in mESCs containing a BMP-SMAD responsive reporter transgene. Activation of the BMP-SMAD reporter transgene in naive mESCs correlated with lower levels of genomic DNA methylation, high expression of 5-methylcytosine hydroxylases Tet1/2 and low levels of DNA methyltransferases Dnmt3a/b. Moreover, naive mESCs, in which the BMP-SMAD reporter transgene was activated, showed higher resistance to differentiation. Using double Smad1;Smad5 knockout mESCs, we showed that BMP-SMAD signaling is dispensable for self-renewal in both naive and ground state. These mutant mESCs were still pluripotent, but they exhibited higher levels of DNA methylation than their wild-type counterparts and had a higher propensity to differentiate. We showed that BMP-SMAD signaling modulates lineage priming in mESCs, by transiently regulating the enzymatic machinery responsible for DNA methylation.
- Published
- 2016
- Full Text
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50. GROWTH AND MICRONUTRIENT CONCENTRATION IN MAIZE PLANTS UNDER NICKEL AND LIME APPLICATIONS
- Author
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GILMAR NUNES TORRES, SÂNIA LÚCIA CAMARGOS, OSCARLINA LUCIA DOS SANTOS WEBER, KELLY DAYANA BENEDET MAAS, and WALCYLENE MATOS PEREIRA SCARAMUZZA
- Subjects
Agriculture ,Biology (General) ,QH301-705.5 - Abstract
The experiment was conducted in a greenhouse located at the Federal University of Mato Grosso, Cuiaba - MT, from March to May 2012. The objective was to assess the effects of different rates of nickel application with and without liming on maize growth and micronutrient levels. The study was a randomized block design in a 2 x 5 factorial arrangement with four replicates, for a total of 40 plots, including with and without liming and five rates of nickel application, on a clayey Red Yellow Latosol (Oxisol, USDA classification and Ferralsol, FAO classification). Both lime and nickel applications influenced plant growth, reducing plant development with increased nickel application without liming. It was also observed that both lime and nickel applications altered micronutrient levels in the maize plants, independent of which part of the plant was evaluated. Nickel played an antagonistic role with manganese and zinc and a synergistic role with copper and iron.
- Published
- 2016
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