116 results on '"T Kretzschmar"'
Search Results
2. Inhibition of ceramide synthesis improves the outcome in ischemia/reperfusion injury using human-induced pluripotent stem cell derived cardiomyocyte
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A Maloku, M Bekhite, J Wu, Marcus Franz, P Haxhikadrija, T Kretzschmar, C Schulze, T Mueller, and M Graeler
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chemistry.chemical_classification ,Reactive oxygen species ,business.industry ,Ceramide synthesis ,Ischemia ,medicine.disease ,Cell biology ,chemistry ,Apoptosis ,Second messenger system ,Medicine ,Signal transduction ,Cardiology and Cardiovascular Medicine ,business ,Induced pluripotent stem cell ,Reperfusion injury - Abstract
Introduction and aim Ceramides are proven to be biologically active in apoptosis, inflammation, mitochondrial dysfunction, and as a second messenger in various signaling pathways1. However, the data linking the role of ceramides in ischemia/reperfusion injury (I/R injury) are lacking. We aimed to establish an I/R injury model using human-induced pluripotent stem cell (hiPSC)-derived cardiomyocyte (CM) and to evaluate ceramide levels, ceramide synthesis pathway, and outcome of CM with inhibition of ceramide synthesis during I/R injury. Methods HiPSC technology has been used to generate functional human CMs to elucidate the underlying mechanisms of the pathophysiology of the human heart. Results In our model, we observed an increase of mRNA levels of genes regulating ceramide synthesis after 6 h of ischemia followed by 16 h reperfusion, such as SPTLC1 (1.1±0.08 vs 1.0, p=0.2), CerS2 (1.6±0.3 vs 1.0, p Inhibition of ceramide synthesis with Fumonisin B1 (FB1) significantly increased the viability after 6h of ischemia followed by 16 h of reperfusion compared to CMs incubated without inhibitors (32.2%±1.5% vs 26.9%±2.6%, p=0.04). Interestingly, we identified two mechanisms with which the viability improves after incubation with ceramide inhibitor. The first mechanism observed could be the restoration of both intracellular calcium baseline (control 29±1.2, I/R 55±5.7 and I/R with FB1 35.6±2.5, p Conclusion We conclude that ceramides have important implications in either mediating or causing injury and their inhibition improves the outcome of I/R injury by decreasing ROS generation and improving calcium oscillations. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): Jena University Hospital, Clinic for Internal Medicine 1Interdisciplinary Center for Clinical Research Jena
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- 2021
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3. Kynurenine as a potential biomarker in detecting reduced muscle endurance: metabolomic profiling of patients with heart failure and exercise intolerance
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Tarek Bekfani, Marcus Franz, A Hamadanchi, M Kiehntopf, M.F Wu, M Bekhite, Rüdiger C. Braun-Dullaeus, S Moebius-Winkler, Daniela Haase, M Lichtenauer, T Kretzschmar, Paul Christian Schulze, S Neugebauer, S Derlien, and S. Von Haehling
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medicine.medical_specialty ,business.industry ,Exercise intolerance ,Muscle endurance ,medicine.disease ,chemistry.chemical_compound ,Metabolomic profiling ,chemistry ,Internal medicine ,Heart failure ,Potential biomarkers ,Cardiology ,Medicine ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business ,Kynurenine - Abstract
Aims Reduced muscle endurance (RME) in patients with HFpEF and HFrEF is associated with structural and metabolic changes in skeletal muscle. We investigated the role of kynurenine (Kyn) as a potential marker in detecting RME. Additionally, we described the likely distorted metabolic pathways in serum in patients with RME and both preserved (HFpEF) and reduced (HFrEF) ejection fraction. Methods Fifty-five participants were prospectively recruited (17 HFpEF, 18 HFrEF outpatients and 20 healthy controls, HC). All participants underwent echocardiography, CPET, isokinetic muscle function tests. Quantification of metabolites in serum was performed using liquid chromatography tandem mass spectrometry. Results In a linear regression, Kyn was an independent predictor for RME after adjusting for alanine, glutamate, ornithine, spermine and short-chain-ACs (B: −8.2 per 1μM increase, 95% CI: −13.01, −3.30, p=0.001). Kyn showed 83% sensitivity and 70% specificity (area under the curve 0.83) in detecting RME. Patients with RME and HFpEF showed reduced levels of long-chain-, medium-chain-, medium-/long-chain-ACs ratios and alanine (p Conclusions Kyn shows high potential as biomarker for detecting RME. RME was associated with impaired fatty acid oxidation rates in HFpEF patients and with reduced concentrations of AAs in those with HFrEF. Funding Acknowledgement Type of funding sources: None.
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- 2021
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4. Doxorubicin induced cardiotoxicity is mediated by increased CerS2 expression and ceramide accumulation in vitro and in vivo
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T Kretzschmar, J M F Wu, M Bekhite, K Gruen, J Bogoviku, T Mueller, M Graeler, M Franz, and P C Schulze
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Cardiology and Cardiovascular Medicine - Abstract
Background Doxorubicin (Dox) is a chemotherapeutic drug with cardiotoxicity as a severe side effect. Interestingly, Dox increases the expression of ceramide synthase 2 (CerS2) and increases long- chain ceramide levels with proinflammatory effects. Aim The purpose of our study was to identify the role of increased long- chain ceramides synthesized by CerS2 in Dox mediated cardiotoxicity in vitro and in vivo. Methods We incubated HL-1 cells (murine cardiomyocytes) with 0.7 μM Dox for 24h. In parallel cells were pretreated with fumonisin B (100 μM, 4h, FuB) to reduce Dox effects. We generated CerS2 ko mice and treated them with Dox and also generated doxycycline- inducible CerS2 mice. Expression of genes and proteins were measured with immunofluorescence (IF), western blot (WB) or qPCR. Ceramide levels were determined with mass spectrometry. Cellular staining was assessed by confocal laser scanning microscopy. Mitochondrial viability and activity were detected using seahorse analyzer. Results Protein expression measurement showed increased CerS2 level in vitro (2.4±0.32, p=0.03 for WB, 2.2±0.10, p Conclusion Our data show that Dox mediated cardiotoxicity is in part mediated by CerS2 and ceramides. CerS2 could be a valuable drug target for treatment of chemotherapy- associated cardiomyopathies. Funding Acknowledgement Type of funding sources: None. Immunofluorescence HL-1
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- 2021
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5. [52/f-Acute chest pain : Preparation for the medical specialist examination: part 93]
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T, Kretzschmar and C, Misgeld
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Chest Pain ,Humans ,Medicine - Published
- 2021
6. P4228Metabolomic profiles and transcriptional changes during early and late differentiation of cardiomyocytes derived from human induced pluripotent stem cells
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Boris Greber, P C Schulze, T Kretzschmar, M B Elsaied, and A G Delgado
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business.industry ,Medicine ,Human Induced Pluripotent Stem Cells ,Cardiology and Cardiovascular Medicine ,business ,Cell biology - Published
- 2018
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7. 5216Prognostic impact of serum metabolomic profiling of patients with heart failure with reduced ejection fraction
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S Neugebauer, Rudin Pistulli, Marcus Franz, Bettina Heidecker, D. Kretzschmar, Paul Christian Schulze, M Kiehntopf, and T Kretzschmar
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medicine.medical_specialty ,Metabolomic profiling ,Ejection fraction ,business.industry ,Internal medicine ,Heart failure ,Cardiology ,Medicine ,Cardiology and Cardiovascular Medicine ,business ,medicine.disease - Published
- 2018
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8. P4226Metabolomic profiles of human cardiomyocytes derived from induced pluripotent stem cells under diabetic conditions
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A G Delgado, M B Elsaied, Boris Greber, A Kumar, M Graeler, P C Schulze, and T Kretzschmar
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business.industry ,Medicine ,Cardiology and Cardiovascular Medicine ,Induced pluripotent stem cell ,business ,Cell biology - Published
- 2018
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9. P4733Growth factors and atrophy-related genes are highly expressed in patients with HFpEF and are associated with elevated BNP and reduced exercise capacity and quality of life
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Tarek Bekfani, G Lehmann, Jenny Nisser, A Hamadanchi, Daniela Haase, M Bekhite Elsaied, S Derlien, E Froeb, G Wolf, Ulrich C. Smolenski, T Kretzschmar, S Moebius-Winkler, and Paul Christian Schulze
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medicine.medical_specialty ,Atrophy ,Quality of life ,business.industry ,Internal medicine ,medicine ,In patient ,Exercise capacity ,Cardiology and Cardiovascular Medicine ,business ,medicine.disease ,Gene - Published
- 2018
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10. P164Serum metabolomic profiling of patients with heart failure with reduced ejection fraction reveals differences between ischemic and dilated cardiomyopathy
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Paul Christian Schulze, D. Kretzschmar, I. Rohm, Rudin Pistulli, S Neugebauer, M Kiehntopf, and T Kretzschmar
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medicine.medical_specialty ,Metabolomic profiling ,Ejection fraction ,business.industry ,Heart failure ,Internal medicine ,medicine ,Cardiology ,Dilated cardiomyopathy ,Cardiology and Cardiovascular Medicine ,medicine.disease ,business - Published
- 2017
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11. Hydrological modeling of climate change impacts in a Tropical River Basin: A case study of the Cauto River, Cuba
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Montecelos-Zamora, Y. Cavazos, T. Kretzschmar, T. Vivoni, E. R. Corzo, G. Molina-Navarro, E. and Montecelos-Zamora, Y. Cavazos, T. Kretzschmar, T. Vivoni, E. R. Corzo, G. Molina-Navarro, E.
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The soil and water assessment tool (SWAT) model was applied for the first time in Cuba to assess the potential impacts of climate change on water availability in the Cauto River basin. The model was calibrated (and validated) for the 2001–2006 (2007–2010) period at a monthly timescale in two subbasins La Fuente and Las Coloradas, representative of middle and upper sections of the Cauto basin; the calibrated models showed good performance. The output available for the regional climate Model RegCM4.3 was used to force the calibrated SWAT models to simulate a baseline (1970–2000) period and near-future (2015–2039) hydrologic regimes under the representative concentration pathway (RCP) 8.5 emission scenario. The future projections suggest regional increases of 1.5 °C in mean annual temperature and a 38% decrease in mean annual precipitation in the subbasins. These changes translate to possible reductions in the annual streamflow of up to 61% with respect to the baseline period, whereas the aquifer recharge in the basin is expected to decrease up to 58%, with a consequent reduction of groundwater flow, especially during the boreal summer wet season. These projection scenarios should be of interest to water resources managers in tropical regions.
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- 2018
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12. Cyclic disulfide analogues of the complement component C3a Synthesis and conformational investigations
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D Ambrosius, Hartwig Höcker, Axel Wollmer, D Bitter-Suermann, Joachim Grötzinger, Martina Pohl, Derek Saunders, T Kretzschmar, and Brandenburg D
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Formic Acid Esters ,Protein Conformation ,Stereochemistry ,Molecular Sequence Data ,chemical and pharmacologic phenomena ,Peptide ,Peptides, Cyclic ,Biochemistry ,Acylation ,chemistry.chemical_compound ,Protein structure ,Computer Graphics ,Peptide synthesis ,Humans ,Amino Acid Sequence ,Disulfides ,Sulfhydryl Compounds ,Amino Acids ,Peptide sequence ,chemistry.chemical_classification ,Fluorenes ,Chemistry ,Circular Dichroism ,Cyclic peptide ,Complement C3a ,Benzyl group ,Thermodynamics ,Oxidation-Reduction ,Iodine ,Cysteine - Abstract
The flexible C-terminal region of the anaphylatoxic peptide C3a was reported to contain the receptor binding site. To elucidate the receptor binding conformation of the C-terminus, as well as to examine a synthetic approach to potential C3a-antagonists, 26 cyclic disulfide bridged C3a analogues were synthesized. Solid phase peptide synthesis was performed on different polymeric supports by individual peptide synthesis, with Fmoc strategy, and simultaneous multiple peptide synthesis, using Boc and Fmoc strategies. Both strategies gave open-chain peptides in comparable yields. Syntheses using the Boc strategy employed the HF-labile 4(methoxy)benzyl group (Mob) for beta-thiol protection of cysteine; in contrast, the TFA-stable protecting groups, acetamidomethyl (Acm) and trityl (Trt), were chosen for syntheses employing Fmoc strategy. Ring closure reactions by iodine oxidation were carried out starting from protected (Acm/Acm, Trt/Acm) or unprotected dithiols. The resulting cyclic C3a analogues were characterized by HPLC, amino acid analysis, and FAB-MS. Conformational investigations using CD spectroscopy and theoretical structural investigations by means of molecular dynamics calculations revealed that slight variations in sequence result in pronounced conformational consequences. The potential of cyclic C3a analogues to activate or to desensitize guinea pig platelets, a standard test system for biological activities of anaphylatoxic peptides like C3a, revealed relatively low activities for cyclic peptides (< 0.1% C3a activity). N-terminal acylation with cationic, arginine-rich sequences like YRRGR- led to amplified biological effects. Three of the synthesized peptides, namely CAALCLAR (P1), YRRGRCGGLCLAR (P5) and YRRGRAhxCGGLCLAR (P8), point in the direction of C3a antagonists.
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- 2009
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13. Characterization of rubber-brass bonding layers by analytical electron microscopy (AEM)
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Ferdinand Hofer, Klaus Hummel, T. Kretzschmar, and G. Grubbauer
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Materials science ,Analytical chemistry ,chemistry.chemical_element ,Surfaces and Interfaces ,General Chemistry ,Substrate (electronics) ,Copper ,Surfaces, Coatings and Films ,Characterization (materials science) ,law.invention ,Brass ,Electron diffraction ,Chemical engineering ,chemistry ,Mechanics of Materials ,Transmission electron microscopy ,law ,visual_art ,Scanning transmission electron microscopy ,Materials Chemistry ,visual_art.visual_art_medium ,Electron microscope - Abstract
The mechanical properties of rubber- brass bonding systems depend on the morphology, chemistry, and crystallography of the phases in the sulfide layers which are formed during cure. These layers contain the crystalline high-digenite and chalcocite copper sulfides. Most of the bonding layers are relatively thin and consist of several phases which can be visualized by electron microscopy (EM). Their characterization requires structural and elemental analyses with high spatial resolution. Analytical electron microscopy (AEM) fulfils these requirements. For a successful application of AEM, suitable specimen preparation is a major prerequisite. Two preparation techniques are discussed: the extraction of the bonding layers parallel to the substrate and the preparation by cryo-ultramicrotomy of cross-sections perpendicular to the brass surface. The bonding layers are characterized by means of transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), electron diffraction, energy-di...
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- 1996
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14. Rubber-brass bonding: morphology of cross-sections through the bonding layers as a possible basis for classification
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Klaus Hummel, T. Kretzschmar, and Ferdinand Hofer
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Morphology (linguistics) ,Materials science ,Vulcanization ,chemistry.chemical_element ,Surfaces and Interfaces ,General Chemistry ,Zinc ,Copper ,Surfaces, Coatings and Films ,law.invention ,Brass ,chemistry ,Natural rubber ,Mechanics of Materials ,law ,Transmission electron microscopy ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Composite material ,Layer (electronics) - Abstract
The extensive literature on rubber-brass bonding provides a rather complex picture of the architecture of the bonding layers. In the present work, the morphology of cross-sections through the bonding layers perpendicular to the brass surface, seen in transmission electron microscopy (TEM), is used as a means of bonding layer classification. Previous experimental results with a simplified cure mixture (consisting of 1,4-polybutadiene, elemental sulfur, N,N-dicyclohexyl-2-benzothiazylsulfenamide, and, in some cases, zinc oxide) and brass foils are reconsidered. In nearly all cases, what we term a central layer is found. It consists of two sublayers with a different content of copper sulfides. Varying deposits of sulfides exist at the brass surface and also above the central layer in the direction of the rubber bulk. The various types of bonding layer with a different type of architecture are discussed in connection with previous results obtained by analytical electron microscopy (AEM) and bonding strength m...
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- 1996
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15. Selection Procedures for Nonmatured Phage Antibodies: A Quantitative Comparison and Optimization Strategies
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C. Zimmermann, T. Kretzschmar, and M. Geiser
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Nonspecific binding ,biology ,Fv Antibody Fragment ,Biophysics ,Cell Biology ,Phage antibodies ,Computational biology ,Antibodies, Viral ,biology.organism_classification ,Biochemistry ,Combinatorial chemistry ,Chromatography, Affinity ,Microtiter plate ,Filamentous bacteriophage ,Bacteriophages ,Panning (camera) ,Molecular Biology ,Selection (genetic algorithm) - Abstract
Libraries of peptides and proteins can be displayed on the surface of filamentous bacteriophage. The efficient capturing of phage recognizing a defined target molecule remains a serious obstacle, in particular when the phage are present at a low frequency or have a reduced affinity like nonmatured phage antibodies and when the availability of target molecules is limited. We present theoretical considerations and experimental data which allowed us to substantially improve microselection under these conditions. We used a model phage displaying an anti-(2-phenyl-5-oxazolone) single-chain Fv antibody fragment. Following standard protocols and aiming at a low nonspecific binding, only 3.6 × 10 −3 % of the phage input could be recovered from a single round of selection performed in the wells of a microtiter plate. Our results explain why this often employed panning in wells is not efficient, especially with high-molecular-weight target molecules. We devised a procedure which increased the probability of microselection by a factor of 34. An alternative capturing method using immunotubes with a new protocol decreased the amount of required work by a factor of 30. In the case of a nonlimited supply of target molecules, column-affinity chromatography is recommended.
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- 1995
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16. The Influence of Different Brass Pretreatments on Rubber-Metal Bonding: Investigated by Analytical Electron Microscopy
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Ferdinand Hofer, Klaus Hummel, and T. Kretzschmar
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Materials science ,Aqueous solution ,Polymers and Plastics ,Vulcanization ,Mineralogy ,Elastomer ,law.invention ,Rubbing ,Brass ,Natural rubber ,law ,Etching (microfabrication) ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Composite material ,Metallic bonding - Abstract
Brass samples (thin foils or plates) were pretreated either by etching with aqueous HC1 or by rubbing with emery cloth. A mixture of cis-l,4-polybutadiene with sulfur and N,N-dicyclohexyl-2-benzothiazylsulfenamide was vulcanized in contact with the brass surfaces. The bonding layers were investigated by analytical electron microscopy (AEM). Two preparation techniques for AEM were used, namely cryo-ultramicrotomy to obtain cross sections (applied to foils), or separating ultrathin surface layers with an aqueous HCl/FeCl3 solution (applied to plates). Across the bonding layers, various crystallographic structures and chemical compositions were found, depending on the pretreatment of the brass.
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- 1993
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17. Functional activities of synthetic anaphylatoxic peptides in widely used biological assays
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Andreas Klos, Jörg Köhl, Axel Kola, Wilfried Bautsch, and T Kretzschmar
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Blood Platelets ,Guinea Pigs ,Molecular Sequence Data ,Immunology ,chemical and pharmacologic phenomena ,Peptide ,In Vitro Techniques ,Biology ,Adenosine Triphosphate ,Ileum ,medicine ,Animals ,Immunology and Allergy ,Anaphylatoxin ,Amino Acid Sequence ,chemistry.chemical_classification ,Dose-Response Relationship, Drug ,C-terminus ,Muscle, Smooth ,Biological activity ,In vitro ,Amino acid ,Mechanism of action ,chemistry ,Biochemistry ,Complement C3a ,Specific activity ,medicine.symptom ,Muscle Contraction ,Research Article - Abstract
SUMMARY A comparison study was carried out between the modern ATP release assay (ARA) with guinea-pig platelets and the traditional guinea-pig ileum contraction assay (ICA). The biological activities of the anaphylatoxin C3a and synthetic C3a analogue peptides were determined in both assays. In dose-response curves with C3a, a human C3a peptide with the last 21 amino acids of the C terminus (C3a 56–77) and a peptide with 13 amino acids which was acylated N-terminal with the aromatic fluorenylmethoxycarbonyl group and an aminohexanoyl group (Fmoc-Ahx YRRGRAAALGLAR) were tested. The ARA turned out to be 100 times more sensitive than the ICA. In contrast to previous reports the 21 amino acid long C3a analogue peptide did not exhibit full C3a activity but only 7% (ARA) or 12% (ICA). The potentiation of biological activity in the ARA by coupling non-peptide acyl-residues N terminal to peptidic C3a analogues could be confirmed with Fmoc-Ahx-YRRGRAAALGLAR in the ICA. In addition, the tri-peptide Fmoc-Ahx-LAR displayed C3a specific activity in the ICA demonstrated by desensitization experiments.
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- 1992
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18. Numerical understanding of regional scale water table behavior in the Guadalupe Valley aquifer, Baja California, Mexico
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T. Kretzschmar, J. R. Campos-Gaytan, Departamento de Geofisica Aplicada, Centro de Investigacion Científica y de Educacion Superior de Ensenada, and EGU, Publication
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Hydrology ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,geography ,Hydrogeology ,geography.geographical_feature_category ,Resource (biology) ,010504 meteorology & atmospheric sciences ,Groundwater flow ,[SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere ,Water table ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,Aquifer ,010502 geochemistry & geophysics ,01 natural sciences ,[SDU.ENVI] Sciences of the Universe [physics]/Continental interfaces, environment ,6. Clean water ,[SDU.STU] Sciences of the Universe [physics]/Earth Sciences ,Groundwater model ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,Surface water ,Groundwater ,Geology ,0105 earth and related environmental sciences - Abstract
A regional groundwater flow model was developed, in order to evaluate the water table behavior in the region of the Guadalupe Valley, in Baja California, Mexico. The State of Baja California has been subject to an increment of the agricultural, urban and industrials activities, implicating a growing water-demand. However, the State is characterized by its semi-arid climate with low surface water availability; resulting in an extensive use of groundwater in local aquifer. Based on historic piezometric information of the last two decades, however, a negative evolution could be observed, resulting a negative storage volume. So far, there is not an integral hydrogeological evaluation that determine the real condition of the groundwater resource, and that permit to planning a management of the Guadalupe Valley Aquifer. A steady-state calibration model was carried out in order to obtain the best possible match to measured levels at the Guadalupe Valley Aquifer. The contours of calculated water table elevations for January 1983 were reproduced. Generally, the comparison of the observed and calculated water table configurations have a good qualitative and quantitatively adjustment. Nowadays, it is count with a hydrogeological model that can be used for simulates the groundwater flow in the region of the Guadalupe Valley.
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- 2006
19. Bypassing hybridoma technology: HLA-C reactive human single-chain antibody fragments (scFv) derived from a synthetic phage display library (HuCAL) and their potential to discriminate HLA class I specificities
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M, Marget, B B, Sharma, M, Tesar, T, Kretzschmar, S, Jenisch, E, Westphal, P, Davarnia, E, Weiss, M, Ulbrecht, D, Kabelitz, and M, Krönke
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Immunoglobulin Fab Fragments ,Antibody Specificity ,Peptide Library ,Histocompatibility Antigens Class I ,Humans ,HLA-C Antigens ,Lymphocytes ,Flow Cytometry ,Transfection ,Precipitin Tests ,Alleles ,Cell Line - Abstract
The generation of discriminative, monospecific anti-HLA antibodies used to be a difficult endeavor. Phage display technology, using single-chain antibody fragments (scFv) offers a powerful alternative obtaining target-specific, genetically stable reagents. Most of scFv obtained to date have been enriched by panning phage libraries to solid-phase coupled antigens. In the present study, HLA-C-specific scFv were isolated using a synthetic phage library in combination with a Cw*0602 overexpressing cell line. ScFv from this procedure precipitated HLA-Cw*0602 heavy chains from whole cell lysates. Flow cytometry analysis revealed that scFv stained HLA-Cw*0602-positive cells, but not cells expressing HLA alleles Cw*0302, Cw*0802, A*0201, B*2705, or Gm1*01011, indicating the specificity of scFv. Similarly they showed an ability to discriminate Cw*0602-positive from Cw*0602-negative peripheral blood lymphocytes (PBL). The results of our study demonstrate the feasibility to genetically engineer single-chain HLA-class I-specific antibodies, by phage display technology. This approach might be a valuable tool to develop a broad range of novel monospecific antibodies against HLA-class I specificities.
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- 2000
20. Investigation of the rubber-metal bonding system by means of analytical electron microscopy and comparison with results of technical tear strength measurements
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T. Kretzschmar, Ferdinand Hofer, Klaus Hummel, Werner Grogger, and G. Grubbauer
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Tear resistance ,Materials science ,Vulcanization ,Analytical chemistry ,chemistry.chemical_element ,Biochemistry ,Copper ,Analytical Chemistry ,law.invention ,Brass ,Electron diffraction ,Natural rubber ,chemistry ,law ,visual_art ,visual_art.visual_art_medium ,Composite material ,Layer (electronics) ,Metallic bonding - Abstract
During vulcanization of sulfur-cure mixtures in contact with brass, a bonding layer consisting of sublayers of copper and zinc sulfides and oxides is formed. As the chemical composition and structure of the layer are decisive for good adhesion. the rubber to brass bonding was investigated using an analytical electron microscope (AEM) coupled with an energy dispersive X-ray (EDX) detector. Sublayers were found in the bonding layer between rubber and brass. Different crystallographic phases were identified in an etched bonding layer by electron diffraction. Technical tear strength measurements were carried out using rubber-brass-rubber samples, showing correlations with the electron microscopic investigations. This method is a new approach to the rubber-metal bonding (adhesion) problem.
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- 1994
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21. Characterisation of Cannabis glandular trichome development reveals distinct features of cannabinoid biosynthesis.
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Nolan M, Guo Q, Liu L, Dimopoulos N, Garcia-de Heer L, Barkla BJ, and Kretzschmar T
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- Gene Expression Regulation, Plant, Metabolomics, Proteomics methods, Trichomes metabolism, Trichomes growth & development, Cannabis growth & development, Cannabis metabolism, Cannabis genetics, Cannabinoids metabolism, Terpenes metabolism, Plant Proteins metabolism, Plant Proteins genetics
- Abstract
Key Message: Cannabis trichome development progresses in distinct phases that underpin the dynamic biosynthesis of cannabinoids and terpenes. This study investigates the molecular mechanisms underlying cannabinoid and terpenoid biosynthesis in glandular trichomes of Cannabis sativa (CsGTs) throughout their development. Female Cannabis sativa c. Hindu Kush were cultivated under controlled conditions, and trichome development was analysed from week 3 to week 8 of the flowering period. We employed light microscopy, quantitative metabolomics and proteomics to analyse morphological changes in trichome secretory cell development, and temporal changes in metabolite accumulation and protein abundance. Our findings identified three distinct developmental phases: pre-secretory (T3), secretory (T6), and post-secretory (T8), the first time the three phases of trichome development have been identified and investigated in CsGTs. The pre-secretory phase was characterized by smaller secretory cells, limited metabolite accumulation and elevated levels of proteins involved in protein biosynthesis and cellular development. The secretory phase exhibited the highest biosynthetic activity, marked by larger secretory cells, increased plastidal activity, central carbon metabolism, and significant accumulation of cannabinoids and terpenoids. The post-secretory phase showed a decrease in secretory cell size, reduced metabolic activity, and a decrease in the abundance of primary and secondary metabolism enzymes, although THCA continued to accumulate. Key enzymes showed dynamic changes correlating with the stages of trichome development. This study provides a comprehensive understanding of the molecular mechanisms regulating cannabinoid and terpenoid biosynthesis in CsGTs, offering insights for enhancing the production of these valuable compounds through targeted breeding and biotechnological approaches., Competing Interests: Declarations. Conflict of interest: The authors declare that Cann Group Ltd was a funding partner for this project through the CRC-P program., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
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- 2025
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22. From dawn 'til dusk: daytime progression regulates primary and secondary metabolism in Cannabis glandular trichomes.
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Dimopoulos N, Guo Q, Purdy SJ, Nolan M, Halimi RA, Mieog JC, Barkla BJ, and Kretzschmar T
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- Cannabinoids metabolism, Plant Proteins metabolism, Plant Proteins genetics, Circadian Rhythm, Proteome metabolism, Flowers metabolism, Trichomes metabolism, Cannabis metabolism, Terpenes metabolism, Secondary Metabolism
- Abstract
Cannabis sativa L. glandular trichomes synthesize large amounts of secondary metabolites, predominantly cannabinoids and terpenoids. The associated demand for carbon and energy makes glandular trichomes strong sink tissues with indications that their secondary metabolism is coupled to the availability of photoassimilates. Many metabolites show diurnal patterns of flux, but it is unknown whether cannabinoids and terpenoids are regulated by time of day. We quantified cannabinoids, terpenoids, and the glandular trichome proteome over a 12 h light period in flowers of 'Hindu Kush', a high-tetrahydrocannabinol cultivar. Major cannabinoids changed significantly over the course of the day, resulting in an increase in total measured cannabinoids. Major terpenoids also changed, with sesquiterpenes generally decreasing with day progression. While monoterpenes generally did not decrease, the second most abundant, α-pinene, increased. The glandular trichome proteome changed the most within the first 6 h of the day, and analysis of differentially abundant proteins indicated up-regulation of primary metabolism. Surprisingly, key cannabinoid biosynthetic enzymes decreased with daytime progression despite increases in cannabinoid content, which indicates that daytime increases of photoassimilates are the main driver of cannabinoid regulation. This first reporting of variability of cannabinoid and terpenoid biosynthesis over the course of the day has implications for Cannabis research and production., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)
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- 2025
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23. Machine learning approach for high-throughput phenolic antioxidant screening in black Rice germplasm collection based on surface FTIR.
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Herath A, Tiozon RJ, Kretzschmar T, Sreenivasulu N, Mahon P, and Butardo V Jr
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- Spectroscopy, Fourier Transform Infrared, Seeds chemistry, High-Throughput Screening Assays, Oryza chemistry, Machine Learning, Antioxidants chemistry, Phenols chemistry, Phenols analysis
- Abstract
Pigmented rice contains beneficial phenolic antioxidants but analysing them across germplasm collections is laborious and time-consuming. Here we utilised rapid surface Fourier transform infrared (FTIR) spectroscopy and machine learning algorithms (ML) to predict and classify polyphenolic antioxidants. Total phenolics, flavonoids, anthocyanins, and proanthocyanidins were quantified biochemically from 270 diverse global coloured rice collection and attenuated total reflectance (ATR) FTIR spectra were obtained by scanning whole grain surfaces at 800-4000 cm
-1 . Five ML classification models were optimised using the biochemical and spectral data which performed predictions with 93.5%-100% accuracy. Random Forest and Support Vector Machine models identified key FTIR peaks linked to flavonols, flavones and anthocyanins as important model predictors. This research successfully established direct and non-destructive surface chemistry spectroscopy of the aleurone layer of pigmented rice integrated with ML models as a viable high-throughput platform to accelerate the analysis and profiling of nutritionally valuable coloured rice varieties., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Tobias Kretzschmar reports financial support was provided by Australian Research Council. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2024
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24. Generation of human induced pluripotent stem cell lines UKJi001-A and UKJi006-A from patients with heterozygous mutation in the PKP2 gene.
- Author
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Bekhite MM, Hübner S, Kretzschmar T, Backsch C, Weise A, Klein E, Bogoviku J, Westphal J, and Christian Schulze P
- Subjects
- Humans, Male, Cell Line, Cellular Reprogramming, Cell Differentiation, Arrhythmogenic Right Ventricular Dysplasia genetics, Arrhythmogenic Right Ventricular Dysplasia pathology, Induced Pluripotent Stem Cells metabolism, Induced Pluripotent Stem Cells cytology, Plakophilins genetics, Plakophilins metabolism, Kruppel-Like Factor 4, Heterozygote, Mutation
- Abstract
One of the main signs we do not know enough about arrhythmogenic right ventricular dysplasia 9/cardiomyopathy (ARVCD9, OMIM #609040, autosomal dominant) is the lack of early markers and therapeutic alternatives. To better study disease pathways in vitro, we generated human induced pluripotent stem cell (hiPSC) lines from the father (UKJi006-A) and son (UKJi001-A), who both shared the same heterozygous mutation in the PKP2 gene (OMIM *602861). While the father had a clinical diagnosis of ARVC, the son lacked the ARVC phenotype. To generate hiPSC lines, non-integrating Sendai virus (SeV) vectors expressing the reprogramming factors (OCT4, SOX2, KLF4, and c-MYC) were used for reprogramming patient peripheral blood mononuclear cells (PBMCs)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2024
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25. Generation of a human induced pluripotent stem cell lines (UKJi003-A) from a patient with Fabry disease and healthy donor (UKJi004-A).
- Author
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Bekhite MM, Hübner S, Kretzschmar T, Backsch C, Weise A, Klein E, Bogoviku J, Westphal J, and Schulze PC
- Subjects
- Humans, Cell Line, Leukocytes, Mononuclear metabolism, Cell Differentiation, Sendai virus genetics, Cellular Reprogramming, Male, Fabry Disease pathology, Induced Pluripotent Stem Cells metabolism, Kruppel-Like Factor 4
- Abstract
Fabry disease (FD, OMIM #301500) is a rare metabolic disorder, X-linked glycosphingolipidosis that is characterized by pathogenic mutations in the GLA (Galactosidase Alpha) gene (OMIM *300644) that result in reduced α-galactosidase A (α-GAL) activity and accumulation of globotriaosylceramide (Gb3) in tissues and organs. Peripheral blood mononuclear cells (PBMCs) were used to generate human induced pluripotent stem cells (hiPSC). UKJi004-A was produced from a healthy donor, whereas UKJi003-A was produced from a patient who had FD with GLA-mutation (IVS6-10G>A). To generate UKJi003-A and UKJi004-A, non-integrating Sendai virus (SeV) vectors expressing four reprogramming factors, OCT4, SOX2, KLF4, and cMYC, were introduced into PBMCs. The pluripotency of the hiPSC lines was confirmed after reprogramming., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2025
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26. Building a community-driven bioinformatics platform to facilitate Cannabis sativa multi-omics research.
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Mansueto L, Kretzschmar T, Mauleon R, and King GJ
- Abstract
Global changes in cannabis legislation after decades of stringent regulation and heightened demand for its industrial and medicinal applications have spurred recent genetic and genomics research. An international research community emerged and identified the need for a web portal to host cannabis-specific datasets that seamlessly integrates multiple data sources and serves omics-type analyses, fostering information sharing. The Tripal platform was used to host public genome assemblies, gene annotations, quantitative trait loci and genetic maps, gene and protein expression data, metabolic profiles and their sample attributes. Single nucleotide polymorphisms were called using public resequencing datasets on three genomes. Additional applications, such as SNP-Seek and MapManJS, were embedded into Tripal. A multi-omics data integration web-service Application Programming Interface (API), developed on top of existing Tripal modules, returns generic tables of samples, properties and values. Use cases demonstrate the API's utility for various omics analyses, enabling researchers to perform multi-omics analyses efficiently., Availability and Implementation: The web portal can be accessed at www.icgrc.info., Competing Interests: The authors declare that they have no competing interests., (© The Author(s) 2024.)
- Published
- 2024
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27. CannSeek? Yes we Can! An open-source single nucleotide polymorphism database and analysis portal for Cannabis sativa .
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Mansueto L, McNally KL, Kretzschmar T, and Mauleon R
- Abstract
A growing interest in Cannabis sativa uses for food, fiber, and medicine, and recent changes in regulations have spurred numerous genomic studies of this once-prohibited plant. Cannabis research uses Next Generation Sequencing technologies for genomics and transcriptomics. While other crops have genome portals enabling access and analysis of numerous genotyping data from diverse accessions, leading to the discovery of alleles for important traits, this is absent for cannabis. The CannSeek web portal aims to address this gap. Single nucleotide polymorphism datasets were generated by identifying genome variants from public resequencing data and genome assemblies. Results and accompanying trait data are hosted in the CannSeek web application, built using the Rice SNP-Seek infrastructure with improvements to allow multiple reference genomes and provide a web-service Application Programming Interface. The tools built into the portal allow phylogenetic analyses, varietal grouping and identifications, and favorable haplotype discovery for cannabis accessions using public sequencing data., Availability and Implementation: The CannSeek portal is available at https://icgrc.info/cannseek, https://icgrc.info/genotype_viewer., Competing Interests: The authors declare that they have no competing interests., (© The Author(s) 2024.)
- Published
- 2024
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28. Importance of Media Composition and Explant Type in Cannabis sativa Tissue Culture.
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Das R, Kretzschmar T, and Mieog JC
- Abstract
Producing uniform Cannabis sativa (Cannabis) for medicinal/recreational flower production through sexual propagation has been problematic, leading to dominance of clonal propagation from "mother plants" in the cannabinoid industry, which also faces significant limitations. Cannabis tissue culture (TC) methods have been developed to overcome these challenges, but the long-term health and maintenance of Cannabis explants in TC have been largely overlooked in previous studies. The current study focused on the development of an efficient and optimized micropropagation protocol covering the entire process, with a specific focus on the health and performance in the multiplication stage. Multiplication media were formulated hormone-free to avoid longer-term vitrification issues, resulting in single-main-shoot cultures rather than multiple-shoot cultures. This instigated the use of stage II explant types different from the standard shoot tips previously used for multiple shoot cultures. Multiplication media were further improved from the basal salt composition via nitrogen and calcium additives. The optimized protocol was used on eight diverse Cannabis cultivars to test its applicability across various genetic backgrounds. Results indicated that the protocol was effective for conservation purposes across all cultivars and achieved good long-term multiplication rates for some but not all. The outcomes of this study mark a significant stride towards an efficient Cannabis TC methodology ready for more comprehensive industrial applications.
- Published
- 2024
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29. HASCH - A high-throughput amplicon-based SNP-platform for medicinal cannabis and industrial hemp genotyping applications.
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Mansueto L, Tandayu E, Mieog J, Garcia-de Heer L, Das R, Burn A, Mauleon R, and Kretzschmar T
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- High-Throughput Nucleotide Sequencing methods, Genome, Plant, Genotype, Polymorphism, Single Nucleotide, Cannabis genetics, Genotyping Techniques methods, Medical Marijuana
- Abstract
Background: Cannabis sativa is seeing a global resurgence as a food, fiber and medicinal crop for industrial hemp and medicinal Cannabis industries respectively. However, a widespread moratorium on the use and research of C. sativa throughout most of the 20th century has seen the development of improved cultivars for specific end uses lag behind that of conventional crops. While C. sativa research and development has seen significant investments in the recent past, resulting in a suite of publicly available genomic resources and tools, a versatile and cost-effective mid-density genotyping platform for applied purposes in breeding and pre-breeding is lacking. Here we report on a first mid-density fixed-target SNP platform for C. sativa., Results: The High-throughput Amplicon-based SNP-platform for medicinal Cannabis and industrial Hemp (HASCH) was designed using a combination of filtering and Integer Linear Programming on publicly available whole-genome sequencing and RNA sequencing data, supplemented with in-house generated genotyping-by-sequencing (GBS) data. HASCH contains 1,504 genome-wide targets of high call rate (97% mean) and even distribution across the genome, designed to be highly informative (> 0.3 minor allele frequency) across both medicinal cannabis and industrial hemp gene pools. Average numbers of mismatch SNP between any two accessions were 251 for medicinal cannabis (N = 116) and 272 for industrial hemp (N = 87). Comparing HASCH data with corresponding GBS data on a collection of diverse C. sativa accessions demonstrated high concordance and resulted in comparable phylogenies and genetic distance matrices. Using HASCH on a segregating F2 population derived from a cross between a tetrahydrocannabinol (THC)-dominant and a cannabidiol (CBD)-dominant accession resulted in a genetic map consisting of 310 markers, comprising 10 linkage groups and a total size of 582.7 cM. Quantitative Trait Locus (QTL) mapping identified a major QTL for CBD content on chromosome 7, consistent with previous findings., Conclusion: HASCH constitutes a versatile, easy to use and cost-effective genotyping solution for the rapidly growing Cannabis research community. It provides consistent genetic fingerprints of 1504 SNPs with wide applicability genetic resource management, quantitative genetics and breeding., (© 2024. The Author(s).)
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- 2024
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30. Quantitative Investigation of Quantum Emitter Yield in Drop-Casted Hexagonal Boron Nitride Nanoflakes.
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Kretzschmar T, Ritter S, Kumar A, Vogl T, Eilenberger F, and Schmidt F
- Abstract
Single photon emitters (SPEs) are a key component for their use as pure photon source in quantum technologies. In this study, we investigate the generation of SPEs from drop-casted hexagonal boron nitride (hBN) nanoflakes, examining the influence of the immersion solution and the source of hBN. We show that, depending on the utilized supplier and solution, the number and quality of the emitters change. We perform a comprehensive optical characterization of the deposited nanoflakes to assess the quality of the generated SPEs. Importantly, we provide quantitative data on SPE yields, highlighting significant variations among solvents and different sources of hBN. We find that hBN from Merck drop-casted in acetone provided the best quality emitters with a g
(2) < 0.1 and photoluminescence intensities above 300 kCounts/s. Their number of SPEs among all photon emitters was also the highest, with about 14%, rendering a total yield of about 1.25% of all drop-casted flakes. These numbers hold particular significance when evaluating drop-casting as a practical method for the generation of SPEs and their deposition and incorporation within existing nanophotonic systems. By choosing appropriate solvents and source materials' quality and yield of SPEs can be significantly increased, showcasing further optimization potential for the development of future quantum applications., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)- Published
- 2024
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31. Why not XY? Male monoecious sexual phenotypes challenge the female monoecious paradigm in Cannabis sativa L.
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Garcia-de Heer L, Mieog J, Burn A, and Kretzschmar T
- Abstract
Monoecy in Cannabis sativa L. has long been considered an industrially important trait due to the increased uniformity it offers and was thought to be exclusively associated with XX females. The isolation and characterisation of a monoecious individual with XY chromosomes sourced from non-proprietary germplasm is reported for the first time. The chromosomal make up of this trait was confirmed through inflorescence structure, growth habit, PCR analysis and sexual phenotypes of progeny from a series of targeted crosses. The identification of an XY monoecious phenotype widens our understanding of monoecy in Cannabis and has important implications for breeding, particularly for producing F1-hybrid seed., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Garcia-de Heer, Mieog, Burn and Kretzschmar.)
- Published
- 2024
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32. Accumulation patterns of anthocyanin and γ-oryzanol during black rice grain development.
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Thapa M, Liu L, Barkla BJ, Kretzschmar T, Rogiers SY, and Rose TJ
- Subjects
- Gene Expression Regulation, Plant, Genotype, Glucosides metabolism, Glucosides biosynthesis, Edible Grain metabolism, Edible Grain genetics, Edible Grain growth & development, Antioxidants metabolism, Plant Proteins metabolism, Plant Proteins genetics, Anthocyanins metabolism, Anthocyanins biosynthesis, Oryza metabolism, Oryza genetics, Oryza growth & development, Phenylpropionates metabolism
- Abstract
Pigmented rice, especially black rice, is gaining popularity as it is rich in antioxidants such as anthocyanins and γ-oryzanol. At present, knowledge about temporal control of biosynthesis and accumulation of antioxidants during grain development is limited. To address this, the accumulation patterns of anthocyanins and γ-oryzanol were assessed in two distinct black rice genotypes over the course of grain development, and the expression of known regulatory genes for anthocyanin biosynthesis was examined. The results indicated that total γ-oryzanol content increased continuously throughout grain development, while total anthocyanins peaked at dough stage (15 to 21 days after flowering) followed by a decline until grain maturity in both genotypes. However, the rate of decrease in anthocyanin content differed between genotypes, and a more prominent decline in cyanidin 3-O-glucoside (C3G) relative to peonidin 3-O-glucoside (P3G) was observed for both. Anthocyanin content was closely linked with the expression of key regulatory genes in the MBW (MYB-bHLH-WD40) complex. This improved knowledge of the genotype-specific biosynthesis (anthocyanins only) and accumulation patterns of anthocyanins and γ-oryzanol can inform subsequent research efforts to increase concentrations of these key antioxidants in black rice grains., Competing Interests: The authors have declared that no competing interests exist, (Copyright: © 2024 Thapa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2024
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33. Metabolic Profiling Identifies 1-MetHis and 3-IPA as Potential Diagnostic Biomarkers for Patients With Acute and Chronic Heart Failure With Reduced Ejection Fraction.
- Author
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Kretzschmar T, Westphal J, Neugebauer S, Wu JMF, Zeller M, Bogoviku J, Bekhite MM, Bekfani T, Schlattmann P, Kiehntopf M, Franz M, and Schulze PC
- Subjects
- Humans, Stroke Volume, Chronic Disease, Biomarkers, Histidine, Heart Failure diagnosis, Indoles, Propionates
- Abstract
Background: Metabolomics has become a valuable tool for identifying potential new biomarkers and metabolic profiles. It has the potential to improve the diagnosis and prognosis of different phenotypes of heart failure. To generate a distinctive metabolic profile, we assessed and compared the metabolic phenotypes of patients with acute decompensated heart failure (ADHF), patients with chronic heart failure (CHF), and healthy controls., Methods: Plasma metabolites were analyzed by liquid-chromatography mass spectrometry/mass spectrometry and the MxP Quant 500 kit in 15 patients with ADHF, 50 patients with CHF (25 with dilated cardiomyopathy, 25 with ischemic cardiomyopathy), and 13 controls., Results: Of all metabolites identified to be significantly altered, 3-indolepropionic acid and 1-methyl histidine showed the highest concentration differences in ADHF and CHF compared with control. Area under the curve-receiver operating characteristic analysis showed an area under the curve ≥0.8 for 3-indolepropionic acid and 1-methyl histidine, displaying good discrimination capabilities between control and patient cohorts. Additionally, symmetrical dimethylarginine (mean, 1.97±0.61 [SD]; P =0.01) was identified as a suitable biomarker candidate for ADHF and kynurenine (mean, 1.69±0.39 [SD]; P =0.009) for CHF when compared with control, both demonstrating an area under the curve ≥0.85., Conclusions: Our study provides novel insights into the metabolic differences between ADHF and CHF and healthy controls. We here identify new metabolites for potential diagnostic and prognostic purposes., Competing Interests: Disclosures Dr Schulze received honoraria for lectures/consulting from Novartis, Vifor, Bayer, Pfizer, Boehringer Ingelheim, AstraZeneca, Cardior, Bristol Myers Squibb, Abiomed, Pharmacosmos, and Amgen not related to this article and research support for the department from Boehringer Ingelheim, Edwards, and Abiomed not related to this article.
- Published
- 2024
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34. Unravelling marker trait associations linking nutritional value with pigmentation in rice seed.
- Author
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Mbanjo EGN, Pasion EA, Jones H, Carandang S, Misra G, Ignacio JC, Kretzschmar T, Sreenivasulu N, and Boyd LA
- Subjects
- Genome-Wide Association Study, Plant Breeding, Pigmentation genetics, Seeds genetics, Oryza genetics
- Abstract
While considerable breeding effort has focused on increasing the yields of staple crops such as rice and the levels of micronutrients such as iron and zinc, breeding to address the problems of the double-burden of malnutrition has received less attention. Pigmented rice has higher nutritional value and greater health benefits compared to white rice. However, the genetic associations underlying pericarp coloration and accumulation of nutritionally valuable compounds is still poorly understood. Here we report the targeted genetic analysis of 364 rice accessions, assessing the genetic relationship between pericarp coloration (measured using multi-spectral imaging) and a range of phenolic compounds with potential nutritional and health-promoting characteristics. A genome-wide association study resulted in the identification of over 280 single nucleotide polymorphisms (SNPs) associated with the traits of interest. Many of the SNPs were associated with more than one trait, colocalization occurring between nutritional traits, and nutritional and color-related traits. Targeted association analysis identified 67 SNPs, located within 52 candidate genes and associated with 24 traits. Six haplotypes identified within the genes Rc/bHLH17 and OsIPT5 indicated that these genes have an important role in the regulation of a wide range of phenolic compounds, and not only those directly conferring pericarp color. These identified genetic linkages between nutritionally valuable phenolic compounds and pericarp color present not only a valuable resource for the enhancement of the nutritional value of rice but an easy method of selection of suitable genotypes., (© 2023 The Authors. The Plant Genome published by Wiley Periodicals LLC on behalf of Crop Science Society of America.)
- Published
- 2023
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35. Autoimmune activation and hypersensitization of the AT1 and ETA receptors contributes to vascular injury in scleroderma renal crisis.
- Author
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Hegner B, Kretzschmar T, Zhu N, Kleinau G, Zhao H, Kamhieh-Milz J, Hilger J, Schindler R, Scheerer P, Riemekasten G, Philippe A, and Catar R
- Subjects
- Rats, Animals, Angiotensin II, Endothelin-1, Autoantibodies, Receptor, Endothelin A, Immunoglobulin G, Vascular System Injuries, Scleroderma, Localized, Acute Kidney Injury
- Abstract
Objectives: Scleroderma renal crisis (SRC) is a rare vascular complication of systemic sclerosis with substantial risks for end-stage renal disease and premature death. Activating autoantibodies (Abs) targeting the angiotensin II type 1 (AT1R) and the endothelin-1 type A receptor (ETAR) have been identified as predictors for SRC. Here, we sought to determine their pathogenic significance for acute renal vascular injury potentially triggering kidney failure and malignant hypertension., Methods: IgG from patients with SRC was studied for AT1R and ETAR dependent biologic effects on isolated rat renal interlobar arteries and vascular cells including contraction, signalling and mechanisms of receptor activation., Results: In myography experiments, patient IgG exerted vasoconstriction sensitive to inhibition of AT1R and ETAR. This relied on MEK-ERK signalling indicating functional relevance of anti-AT1R and anti-ETAR Abs. The contractile response to angiotensin II and endothelin-1 was amplified by patient IgG containing anti-AT1R and anti-ETAR Abs with substantial crosstalk between both receptors implicating autoimmune receptor hypersensitization. Co-immunoprecipitation experiments indicated heterodimerization between both receptor types which may enable the observed functional interrelation by direct structural interactions., Conclusion: We provide experimental evidence that agonistic Abs may contribute to SRC. This effect is presumably related to direct receptor stimulation and additional allosteric effects, at least in heterodimeric receptor constellations. Novel therapies targeted at autoimmune hyperactivation of AT1R and ETAR might improve outcomes in severe cases of SRC., (© The Author(s) 2022. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
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36. Moving Away from 12:12; the Effect of Different Photoperiods on Biomass Yield and Cannabinoids in Medicinal Cannabis.
- Author
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Peterswald TJ, Mieog JC, Azman Halimi R, Magner NJ, Trebilco A, Kretzschmar T, and Purdy SJ
- Abstract
The standard practice to initiate flowering in medicinal cannabis involves reducing the photoperiod from a long-day period to an equal duration cycle of 12 h light (12L)/12 h dark (12D). This method reflects the short-day flowering dependence of many cannabis varieties but may not be optimal for all. We sought to identify the effect of nine different flowering photoperiod treatments on the biomass yield and cannabinoid concentration of three medicinal cannabis varieties. The first, "Cannatonic", was a high cannabidiol (CBD)-accumulating line, whereas the other two, "Northern Lights" and "Hindu Kush", were high Δ9-tetrahydrocannabinol (THC) accumulators. The nine treatments tested, following 18 days under 18 h light/6 h dark following cloning and propagation included a standard 12L:12D period, a shortened period of 10L:14D, and a lengthened period of 14L:10D. The other six treatments started in one of the aforementioned and then 28 days later (mid-way through flowering) were switched to one of the other treatments, thus causing either an increase of 2 or 4 h, or a decrease of 2 or 4 h. Measured parameters included the timing of reproductive development; the dry weight flower yield; and the % dry weight of the main target cannabinoids, CBD and THC, from which the total g cannabinoid per plant was calculated. Flower biomass yields were highest for all lines when treatments started with 14L:10D; however, in the two THC lines, a static 14L:10D photoperiod caused a significant decline in THC concentration. Conversely, in Cannatonic, all treatments starting with 14L:10D led to a significant increase in the CBD concentration, which led to a 50-100% increase in total CBD yield. The results show that the assumption that a 12L:12D photoperiod is optimal for all lines is incorrect as, in some lines, yields can be greatly increased by a lengthened light period during flowering.
- Published
- 2023
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37. Using a global diversity panel of Cannabis sativa L. to develop a near InfraRed-based chemometric application for cannabinoid quantification.
- Author
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Gloerfelt-Tarp F, Hewavitharana AK, Mieog J, Palmer WM, Fraser F, Ansari O, and Kretzschmar T
- Subjects
- Chemometrics, Chromatography, High Pressure Liquid methods, Cannabinoids analysis, Cannabis chemistry, Medical Marijuana
- Abstract
C. sativa has gained renewed interest as a cash crop for food, fibre and medicinal markets. Irrespective of the final product, rigorous quantitative testing for cannabinoids, the regulated biologically active constituents of C. sativa, is a legal prerequisite across the supply chains. Currently, the medicinal cannabis and industrial hemp industries depend on costly chromatographic analysis for cannabinoid quantification, limiting production, research and development. Combined with chemometrics, Near-InfraRed spectroscopy (NIRS) has potential as a rapid, accurate and economical alternative method for cannabinoid analysis. Using chromatographic data on 12 therapeutically relevant cannabinoids together with spectral output from a diffuse reflectance NIRS device, predictive chemometric models were built for major and minor cannabinoids using dried, homogenised C. sativa inflorescences from a diverse panel of 84 accessions. Coefficients of determination (r
2 ) of the validation models for 10 of the 12 cannabinoids ranged from 0.8 to 0.95, with models for major cannabinoids showing best performance. NIRS was able to discriminate between neutral and acidic forms of cannabinoids as well as between C3 -alkyl and C5 -alkyl cannabinoids. The results show that NIRS, when used in conjunction with chemometrics, is a promising method to quantify cannabinoids in raw materials with good predictive results., (© 2023. The Author(s).)- Published
- 2023
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38. Metabolomic Profiling in Patients with Heart Failure and Exercise Intolerance: Kynurenine as a Potential Biomarker.
- Author
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Bekfani T, Bekhite M, Neugebauer S, Derlien S, Hamadanchi A, Nisser J, Hilse MS, Haase D, Kretzschmar T, Wu MF, Lichtenauer M, Kiehntopf M, von Haehling S, Schlattmann P, Lehmann G, Franz M, Möbius-Winkler S, and Schulze C
- Subjects
- Biomarkers metabolism, Humans, Kynurenine, Metabolomics, Stroke Volume physiology, Heart Failure metabolism
- Abstract
Aims: Metabolic and structural perturbations in skeletal muscle have been found in patients with heart failure (HF) both with preserved (HFpEF) and reduced (HFrEF) ejection fraction in association with reduced muscle endurance (RME). We aimed in the current study to create phenotypes for patients with RME and HFpEF compared to RME HFrEF according to their metabolomic profiles and to test the potential of Kynurenine (Kyn) as a marker for RME. Methods: Altogether, 18 HFrEF, 17 HFpEF, and 20 healthy controls (HC) were prospectively included in the current study. The following tests were performed on all participants: isokinetic muscle function tests, echocardiography, spiroergometry, and varied blood tests. Liquid chromatography tandem mass spectrometry was used to quantify metabolites in serum. Results: Except for aromatic and branched amino acids (AA), patients with HF showed reduced AAs compared to HC. Further perturbations were elevated concentrations of Kyn and acylcarnitines (ACs) in HFpEF and HFrEF patients (p < 0.05). While patients with HFpEF and RME presented with reduced concentrations of ACs (long- and medium-chains), those with HFrEF and RME had distorted AAs metabolism (p < 0.05). With an area under the curve (AUC) of 0.83, Kyn shows potential as a marker in HF and RME (specificity 70%, sensitivity 83%). In a multiple regression model consisting of short-chain-ACs, spermine, ornithine, glutamate, and Kyn, the latest was an independent predictor for RME (95% CI: −13.01, −3.30, B: −8.2 per 1 µM increase, p = 0.001). Conclusions: RME in patients with HFpEF vs. HFrEF proved to have different metabolomic profiles suggesting varied pathophysiology. Kyn might be a promising biomarker for patients with HF and RME.
- Published
- 2022
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39. Genome-Wide Association Reveals Trait Loci for Seed Glucosinolate Accumulation in Indian Mustard ( Brassica juncea L.).
- Author
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Tandayu E, Borpatragohain P, Mauleon R, and Kretzschmar T
- Abstract
Glucosinolates (GSLs) are sulphur- and nitrogen-containing secondary metabolites implicated in the fitness of Brassicaceae and appreciated for their pungency and health-conferring properties. In Indian mustard ( Brassica juncea L.), GSL content and composition are seed-quality-determining traits affecting its economic value. Depending on the end use, i.e., condiment or oil, different GSL levels constitute breeding targets. The genetic control of GSL accumulation in Indian mustard, however, is poorly understood, and current knowledge of GSL biosynthesis and regulation is largely based on Arabidopsis thaliana . A genome-wide association study was carried out to dissect the genetic architecture of total GSL content and the content of two major GSLs, sinigrin and gluconapin, in a diverse panel of 158 Indian mustard lines, which broadly grouped into a South Asia cluster and outside-South-Asia cluster. Using 14,125 single-nucleotide polymorphisms (SNPs) as genotyping input, seven distinct significant associations were discovered for total GSL content, eight associations for sinigrin content and 19 for gluconapin. Close homologues of known GSL structural and regulatory genes were identified as candidate genes in proximity to peak SNPs. Our results provide a comprehensive map of the genetic control of GLS biosynthesis in Indian mustard, including priority targets for further investigation and molecular marker development.
- Published
- 2022
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40. Long-Chain and Very Long-Chain Ceramides Mediate Doxorubicin-Induced Toxicity and Fibrosis.
- Author
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Kretzschmar T, Bekhite MM, Wu JMF, Haase D, Förster M, Müller T, Nietzsche S, Westermann M, Franz M, Gräler MH, and Schulze PC
- Subjects
- Adenosine Triphosphate metabolism, Fibroblasts cytology, Fibroblasts drug effects, Fibroblasts metabolism, Fibrosis, Foreskin cytology, Foreskin drug effects, Humans, Male, Mass Spectrometry, Membrane Proteins metabolism, Mitochondria, Heart drug effects, Mitochondria, Heart metabolism, Reactive Oxygen Species metabolism, Signal Transduction drug effects, Sphingosine N-Acyltransferase metabolism, Tumor Suppressor Proteins metabolism, Up-Regulation, Ceramides metabolism, Doxorubicin adverse effects, Foreskin pathology, Membrane Proteins genetics, Sphingosine N-Acyltransferase genetics, Tumor Suppressor Proteins genetics
- Abstract
Doxorubicin (Dox) is a chemotherapeutic agent with cardiotoxicity associated with profibrotic effects. Dox increases ceramide levels with pro-inflammatory effects, cell death, and fibrosis. The purpose of our study was to identify the underlying ceramide signaling pathways. We aimed to characterize the downstream effects on cell survival, metabolism, and fibrosis. Human fibroblasts (hFSF) were treated with 0.7 µM of Dox or transgenically overexpressed ceramide synthase 2 (FLAG-CerS2). Furthermore, cells were pre-treated with MitoTempo (MT) (2 h, 20 µM) or Fumonisin B1 (FuB) (4 h, 100 µM). Protein expression was measured by Western blot or immunofluorescence (IF). Ceramide levels were determined with mass spectroscopy (MS). Visualizations were conducted using laser scanning microscopy (LSM) or electron microscopy. Mitochondrial activity was measured using seahorse analysis. Dox and CerS2 overexpression increased CerS2 protein expression. Coherently, ceramides were elevated with the highest peak for C24:0. Ceramide- induced mitochondrial ROS production was reduced with MT or FuB preincubation. Mitochondrial homeostasis was reduced and accompanied by reduced ATP production. Our data show that the increase in pro-inflammatory ceramides is an essential contributor to Dox side-effects. The accumulation of ceramides resulted in a lipotoxic shift and subsequently mitochondrial structural and functional damage, which was partially reversible following inhibition of ceramide synthesis.
- Published
- 2021
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41. Analysis of Metabolic Markers in Patients with Chronic Heart Failure before and after LVAD Implantation.
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Hilse MS, Kretzschmar T, Pistulli R, Franz M, Bekfani T, Haase D, Neugebauer S, Kiehntopf M, Gummert JF, Milting H, and Schulze PC
- Abstract
Chronic heart failure (HF) is a clinical syndrome characterized by functional impairments of the myocardium. Metabolic and clinical changes develop with disease progression. In an advanced state, left ventricular assist devices (LVADs) are implanted for mechanical unloading. Our study aimed to assess the effects of LVAD implantation on the metabolic phenotypes and their potential to reverse the latter in patients with advanced HF. Plasma metabolites were analyzed by LC-MS/MS in 20 patients with ischemic cardiomyopathy (ICM), 20 patients with dilative cardiomyopathy (DCM), and 20 healthy controls. Samples were collected in HF patients before, 30 days after, and >100 days after LVAD implantation. Out of 188 measured metabolites, 63 were altered in HF. Only three metabolites returned to pre-LVAD concentrations 100 days after LVAD implantation. Pre-LVAD differences between DCM and ICM were mainly observed for amino acids and biogenic amines. This study shows a reversal of metabolite abnormalities in HF as a result of LVAD implantation. The etiology of the underlying disease plays an essential role in defining which specific metabolic parameter is altered in HF and reversed by LVAD implantation. Our findings provide a detailed insight into the disease pattern of ICM and DCM and the potential for reversibility of metabolic abnormalities in HF.
- Published
- 2021
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42. The role of ceramide accumulation in human induced pluripotent stem cell-derived cardiomyocytes on mitochondrial oxidative stress and mitophagy.
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Bekhite M, González-Delgado A, Hübner S, Haxhikadrija P, Kretzschmar T, Müller T, Wu JMF, Bekfani T, Franz M, Wartenberg M, Gräler M, Greber B, and Schulze PC
- Subjects
- Ceramides metabolism, Humans, Myocytes, Cardiac metabolism, Oxidative Stress, Induced Pluripotent Stem Cells, Mitophagy
- Abstract
Oversupply of fatty acids (FAs) to cardiomyocytes (CMs) is associated with increased ceramide content and elevated the risk of lipotoxic cardiomyopathy. Here we investigate the role of ceramide accumulation on mitochondrial function and mitophagy in cardiac lipotoxicity using CMs derived from human induced pluripotent stem cell (hiPSC). Mature CMs derived from hiPSC exposed to the diabetic-like environment or transfected with plasmids overexpressing serine-palmitoyltransferase long chain base subunit 1 (SPTLC1), a subunit of the serine-palmitoyltransferase (SPT) complex, resulted in increased intracellular ceramide levels. Accumulation of ceramides impaired insulin-dependent phosphorylation of Akt through activating protein phosphatase 2A (PP2A) and disturbed gene and protein levels of key metabolic enzymes including GLUT4, AMPK, PGC-1α, PPARα, CD36, PDK4, and PPARγ compared to controls. Analysis of CMs oxidative metabolism using a Seahorse analyzer showed a significant reduction in ATP synthesis-related O
2 consumption, mitochondrial β-oxidation and respiratory capacity, indicating an impaired mitochondrial function under diabetic-like conditions or SPTLC1-overexpression. Further, ceramide accumulation increased mitochondrial fission regulators such as dynamin-related protein 1 (DRP1) and mitochondrial fission factor (MFF) as well as auto/mitophagic proteins LC3B and PINK-1 compared to control. Incubation of CMs with the specific SPT inhibitor (myriocin) showed a significant increase in mitochondrial fusion regulators the mitofusin 2 (MFN2) and optic atrophy 1 (OPA1) as well as p-Akt, PGC-1 α, GLUT-4, and ATP production. In addition, a significant decrease in auto/mitophagy and apoptosis was found in CMs treated with myriocin. Our results suggest that ceramide accumulation has important implications in driving insulin resistance, oxidative stress, increased auto/mitophagy, and mitochondrial dysfunction in the setting of lipotoxic cardiomyopathy. Therefore, modulation of the de novo ceramide synthesis pathway may serve as a novel therapeutic target to treat metabolic cardiomyopathy., (Copyright © 2021 Elsevier Inc. All rights reserved.)- Published
- 2021
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43. Enriched-GWAS and Transcriptome Analysis to Refine and Characterize a Major QTL for Anaerobic Germination Tolerance in Rice.
- Author
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Tnani H, Chebotarov D, Thapa R, Ignacio JCI, Israel WK, Quilloy FA, Dixit S, Septiningsih EM, and Kretzschmar T
- Subjects
- Anaerobiosis, Chromosome Mapping, Gene Expression Profiling, Oryza growth & development, Plant Proteins genetics, Chromosomes, Plant genetics, Genome-Wide Association Study, Germination, Oryza genetics, Plant Proteins metabolism, Polymorphism, Single Nucleotide, Quantitative Trait Loci
- Abstract
Tolerance of anaerobic germination (AG) is a key trait in the development of direct seeded rice. Through rapid and sustained coleoptile elongation, AG tolerance enables robust seedling establishment under flooded conditions. Previous attempts to fine map and characterize AG2 ( qAG7.1 ), a major centromere-spanning AG tolerance QTL, derived from the indica variety Ma-Zhan Red, have failed. Here, a novel approach of "enriched haplotype" genome-wide association study based on the Ma-Zhan Red haplotype in the AG2 region was successfully used to narrow down AG2 from more than 7 Mb to less than 0.7 Mb. The AG2 peak region contained 27 genes, including the Rc gene, responsible for red pericarp development in pigmented rice. Through comparative variant and transcriptome analysis between AG tolerant donors and susceptible accessions several candidate genes potentially controlling AG2 were identified, among them several regulatory genes. Genome-wide comparative transcriptome analysis suggested differential regulation of sugar metabolism, particularly trehalose metabolism, as well as differential regulation of cell wall modification and chloroplast development to be implicated in AG tolerance mechanisms.
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- 2021
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44. Genetic Mapping by Sequencing More Precisely Detects Loci Responsible for Anaerobic Germination Tolerance in Rice.
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Ignacio JCI, Zaidem M, Casal C Jr, Dixit S, Kretzschmar T, Samaniego JM, Mendioro MS, Weigel D, and Septiningsih EM
- Abstract
Direct seeded rice (DSR) is a mainstay for planting rice in the Americas, and it is rapidly becoming more popular in Asia. It is essential to develop rice varieties that are suitable for this type of production system. ASD1, a landrace from India, possesses several traits desirable for direct-seeded fields, including tolerance to anaerobic germination (AG). To map the genetic basis of its tolerance, we examined a population of 200 F
2:3 families derived from a cross between IR64 and ASD1 using the restriction site-associated DNA sequencing (RAD-seq) technology. This genotyping platform enabled the identification of 1921 single nucleotide polymorphism (SNP) markers to construct a high-resolution genetic linkage map with an average interval of 0.9 cM. Two significant quantitative trait loci (QTLs) were detected on chromosomes 7 and 9, qAG7 and qAG9 , with LOD scores of 7.1 and 15.0 and R2 values of 15.1 and 29.4, respectively. Here, we obtained more precise locations of the QTLs than traditional simple sequence repeat and low-density SNP genotyping methods and may help further dissect the genetic factors of these QTLs.- Published
- 2021
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45. Characterization of the Cannabis sativa glandular trichome proteome.
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Conneely LJ, Mauleon R, Mieog J, Barkla BJ, and Kretzschmar T
- Subjects
- Cannabis chemistry, Flowers metabolism, Microscopy, Electron, Scanning methods, Secondary Metabolism, Trichomes chemistry, Cannabis metabolism, Plant Proteins metabolism, Proteome metabolism, Trichomes metabolism
- Abstract
Cannabis sativa has been cultivated since antiquity as a source of fibre, food and medicine. The recent resurgence of C. sativa as a cash crop is mainly driven by the medicinal and therapeutic properties of its resin, which contains compounds that interact with the human endocannabinoid system. Compared to other medicinal crops of similar value, however, little is known about the biology of C. sativa. Glandular trichomes are small hair-like projections made up of stalk and head tissue and are responsible for the production of the resin in C. sativa. Trichome productivity, as determined by C. sativa resin yield and composition, is only beginning to be understood at the molecular level. In this study the proteomes of glandular trichome stalks and heads, were investigated and compared to the proteome of the whole flower tissue, to help further elucidate C. sativa glandular trichome biochemistry. The data suggested that the floral tissue acts as a major source of carbon and energy to the glandular trichome head sink tissue, supplying sugars which drive secondary metabolite biosynthesis. The trichome stalk seems to play only a limited role in secondary metabolism and acts as both source and sink., Competing Interests: First author LJK received a partial stipend from the commercial entity Cann Group Limited. The authors have declared that no competing interests exist. This does not alter our adherence to PLOS ONE policies on sharing data and materials.
- Published
- 2021
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46. Mitochondrial Homeostasis Mediates Lipotoxicity in the Failing Myocardium.
- Author
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Kretzschmar T, Wu JMF, and Schulze PC
- Subjects
- Adipose Tissue metabolism, Calcium Signaling, Cardiomyopathies metabolism, Ceramides biosynthesis, Citric Acid Cycle, Disease Progression, Fatty Acids adverse effects, Homeostasis, Humans, Ketone Bodies metabolism, Mitochondrial Diseases metabolism, Mitophagy, NAD metabolism, Pericardium metabolism, Peroxisome Proliferator-Activated Receptors physiology, Proto-Oncogene Proteins c-bcl-2 physiology, Reactive Oxygen Species metabolism, Fatty Acids metabolism, Heart Failure metabolism, Mitochondria, Heart metabolism, Mitochondrial Dynamics
- Abstract
Heart failure remains the most common cause of death in the industrialized world. In spite of new therapeutic interventions that are constantly being developed, it is still not possible to completely protect against heart failure development and progression. This shows how much more research is necessary to understand the underlying mechanisms of this process. In this review, we give a detailed overview of the contribution of impaired mitochondrial dynamics and energy homeostasis during heart failure progression. In particular, we focus on the regulation of fatty acid metabolism and the effects of fatty acid accumulation on mitochondrial structural and functional homeostasis.
- Published
- 2021
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47. Skeletal Muscle Function, Structure, and Metabolism in Patients With Heart Failure With Reduced Ejection Fraction and Heart Failure With Preserved Ejection Fraction.
- Author
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Bekfani T, Bekhite Elsaied M, Derlien S, Nisser J, Westermann M, Nietzsche S, Hamadanchi A, Fröb E, Westphal J, Haase D, Kretzschmar T, Schlattmann P, Smolenski UC, Lichtenauer M, Wernly B, Jirak P, Lehmann G, Möbius-Winkler S, and Schulze PC
- Subjects
- Aged, Biomarkers metabolism, Biopsy, Case-Control Studies, Echocardiography, Exercise Test, Female, Heart Failure metabolism, Humans, Male, Middle Aged, Muscle, Skeletal metabolism, Prospective Studies, Walk Test, Heart Failure physiopathology, Muscle Strength physiology, Muscle, Skeletal physiopathology, Stroke Volume physiology
- Abstract
Background: Reduced exercise capacity in patients with heart failure (HF) could be partially explained by skeletal muscle dysfunction. We compared skeletal muscle function, structure, and metabolism among clinically stable outpatients with HF with preserved ejection fraction, HF with reduced ejection fraction, and healthy controls (HC). Furthermore, the molecular, metabolic, and clinical profile of patients with reduced muscle endurance was described., Methods: Fifty-five participants were recruited prospectively at the University Hospital Jena (17 HF with preserved ejection fraction, 18 HF with reduced ejection fraction, and 20 HC). All participants underwent echocardiography, cardiopulmonary exercise testing, 6-minute walking test, isokinetic muscle function, and skeletal muscle biopsies. Expression levels of fatty acid oxidation, glucose metabolism, atrophy genes, and proteins as well as inflammatory biomarkers were assessed. Mitochondria were evaluated using electron microscopy., Results: Patients with HF with preserved ejection fraction showed compared with HF with reduced ejection fraction and HC reduced muscle strength (eccentric extension: 13.3±5.0 versus 18.0±5.9 versus 17.9±5.1 Nm/kg, P =0.04), elevated levels of MSTN-2 (myostatin-2), FBXO-32 (F-box only protein 32 [Atrogin1]) gene and protein, and smaller mitochondrial size ( P <0.05). Mitochondrial function and fatty acid and glucose metabolism were impaired in HF-patients compared with HC ( P <0.05). In a multiple regression analysis, GDF-15 (growth and differentiation factor 15), CPT1B (carnitine palmitoyltransferase IB)-protein and oral anticoagulation were independent factors for predicting reduced muscle endurance after adjusting for age (log10 GDF-15 [pg/mL] [B, -54.3 (95% CI, -106 to -2.00), P =0.043], log10 CPT1B per fold increase [B, 49.3 (95% CI, 1.90-96.77), P =0.042]; oral anticoagulation present [B, 44.8 (95% CI, 27.90-61.78), P <0.001])., Conclusions: Patients with HF with preserved ejection fraction have worse muscle function and predominant muscle atrophy compared with those with HF with reduced ejection fraction and HC. Inflammatory biomarkers, fatty acid oxidation, and oral anticoagulation were independent factors for predicting reduced muscle endurance.
- Published
- 2020
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48. An extreme-phenotype genome-wide association study identifies candidate cannabinoid pathway genes in Cannabis.
- Author
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Welling MT, Liu L, Kretzschmar T, Mauleon R, Ansari O, and King GJ
- Subjects
- Genome, Plant, Heterozygote, Cannabinoids metabolism, Cannabis genetics, Genome-Wide Association Study, Phenotype
- Abstract
Cannabis produces a class of isoprenylated resorcinyl polyketides known as cannabinoids, a subset of which are medically important and exclusive to this plant. The cannabinoid alkyl group is a critical structural feature that governs therapeutic activity. Genetic enhancement of the alkyl side-chain could lead to the development of novel chemical phenotypes (chemotypes) for pharmaceutical end-use. However, the genetic determinants underlying in planta variation of cannabinoid alkyl side-chain length remain uncharacterised. Using a diversity panel derived from the Ecofibre Cannabis germplasm collection, an extreme-phenotype genome-wide association study (XP-GWAS) was used to enrich for alkyl cannabinoid polymorphic regions. Resequencing of chemotypically extreme pools revealed a known cannabinoid synthesis pathway locus as well as a series of chemotype-associated genomic regions. One of these regions contained a candidate gene encoding a β-keto acyl carrier protein (ACP) reductase (BKR) putatively associated with polyketide fatty acid starter unit synthesis and alkyl side-chain length. Association analysis revealed twenty-two polymorphic variants spanning the length of this gene, including two nonsynonymous substitutions. The success of this first reported application of XP-GWAS for an obligate outcrossing and highly heterozygote plant genus suggests that this approach may have generic application for other plant species.
- Published
- 2020
- Full Text
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49. Comparative Transcriptomics and Co-Expression Networks Reveal Tissue- and Genotype-Specific Responses of qDTYs to Reproductive-Stage Drought Stress in Rice ( Oryza sativa L.).
- Author
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Tarun JA, Mauleon R, Arbelaez JD, Catausan S, Dixit S, Kumar A, Brown P, Kohli A, and Kretzschmar T
- Subjects
- Computational Biology, Fertility, Gene Expression Profiling, Gene Expression Regulation, Plant, Organ Specificity, Oryza growth & development, Photosynthesis, Plant Leaves genetics, Plant Leaves growth & development, Plant Proteins metabolism, Droughts, Gene Regulatory Networks, Oryza genetics, Plant Proteins genetics, Quantitative Trait Loci, Stress, Physiological, Transcriptome
- Abstract
Rice ( Oryza sativa L.) is more sensitive to drought stress than other cereals. To dissect molecular mechanisms underlying drought-tolerant yield in rice, we applied differential expression and co-expression network approaches to transcriptomes from flag-leaf and emerging panicle tissues of a drought-tolerant yield introgression line, DTY-IL, and the recurrent parent Swarna, under moderate reproductive-stage drought stress. Protein turnover and efficient reactive oxygen species scavenging were found to be the driving factors in both tissues. In the flag-leaf, the responses further included maintenance of photosynthesis and cell wall reorganization, while in the panicle biosynthesis of secondary metabolites was found to play additional roles. Hub genes of importance in differential drought responses included an expansin in the flag-leaf and two peroxidases in the panicle. Overlaying differential expression data with allelic variation in DTY-IL quantitative trait loci allowed for the prioritization of candidate genes. They included a differentially regulated auxin-responsive protein, with DTY-IL-specific amino acid changes in conserved domains, as well as a protein kinase with a DTY-IL-specific frameshift in the C-terminal region. The approach highlights how the integration of differential expression and allelic variation can aid in the discovery of mechanism and putative causal contribution underlying quantitative trait loci for drought-tolerant yield.
- Published
- 2020
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50. Longitudinal metabolic profiling of cardiomyocytes derived from human-induced pluripotent stem cells.
- Author
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Bekhite MM, González Delgado A, Menz F, Kretzschmar T, Wu JMF, Bekfani T, Nietzsche S, Wartenberg M, Westermann M, Greber B, and Schulze PC
- Subjects
- Cells, Cultured, Humans, Cell Differentiation physiology, Induced Pluripotent Stem Cells cytology, Induced Pluripotent Stem Cells metabolism, Myocytes, Cardiac cytology, Myocytes, Cardiac metabolism
- Abstract
Human-induced pluripotent stem cells (h-iPSCs) are a unique in vitro model for cardiovascular research. To realize the potential applications of h-iPSCs-derived cardiomyocytes (CMs) for drug testing or regenerative medicine and disease modeling, characterization of the metabolic features is critical. Here, we show the transcriptional profile during stages of cardiomyogenesis of h-iPSCs-derived CMs. CM differentiation was not only characterized by the expression of mature structural components (MLC2v, MYH7) but also accompanied by a significant increase in mature metabolic gene expression and activity. Our data revealed a distinct substrate switch from glucose to fatty acids utilization for ATP production. Basal respiration and respiratory capacity in 9 days h-iPSCs-derived CMs were glycolysis-dependent with a shift towards a more oxidative metabolic phenotype at 14 and 28 day old CMs. Furthermore, mitochondrial analysis characterized the early and mature forms of mitochondria during cardiomyogenesis. These results suggest that changes in cellular metabolic phenotype are accompanied by increased O
2 consumption and ATP synthesis to fulfill the metabolic needs of mature CMs activity. To further determine functionality, the physiological response of h-iPSCs-derived CMs to β-adrenergic stimulation was tested. These data provide a unique in vitro human heart model for the understanding of CM physiology and metabolic function which may provide useful insight into metabolic diseases as well as novel therapeutic options.- Published
- 2020
- Full Text
- View/download PDF
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