Paris Descartes University

About: Paris Descartes University is a government organization based out in Paris, France. It is known for research contribution in the topics: Population & Transplantation. The organization has 20987 authors who have published 37456 publications receiving 1206222 citations. The organization is also known as: Université Paris V-Descartes & Université de Paris V.

Caspase Activation Is Required for Terminal Erythroid Differentiation

Abstract: The cysteine proteases known as caspases play a central role in most apoptotic pathways. Here, we show that caspase inhibitors arrest the maturation of human erythroid progenitors at early stages of differentiation, before nucleus and chromatin condensation. Effector caspases such as caspase-3 are transiently activated through the mitochondrial pathway during erythroblast differentiation and cleave proteins involved in nucleus integrity (lamin B) and chromatin condensation (acinus) without inducing cell death and cleavage of GATA-1. These observations indicate a new function for caspases as key proteases in the process of erythroid differentiation.

Association of changes in clinical characteristics and management with improvement in survival among patients with ST-elevation myocardial infarction.

Abstract: Context The contemporary decline in mortality reported in patients with ST-segment elevation myocardial infarction (STEMI) has been attributed mainly to improved use of reperfusion therapy. Objective To determine potential factors—beyond reperfusion therapy—associated with improved survival in patients with STEMI over a 15-year period. Design, Setting, and Patients Four 1-month French nationwide registries, conducted 5 years apart (between 1995, 2000, 2005, 2010), including a total of 6707 STEMI patients admitted to intensive care or coronary care units. Main Outcome Measures Changes over time in crude 30-day mortality, and mortality standardized to the 2010 population characteristics. Results Mean (SD) age decreased from 66.2 (14.0) to 63.3 (14.5) years, with a concomitant decline in history of cardiovascular events and comorbidities. The proportion of younger patients increased, particularly in women younger than 60 years (from 11.8% to 25.5%), in whom prevalence of current smoking (37.3% to 73.1%) and obesity (17.6% to 27.1%) increased. Time from symptom onset to hospital admission decreased, with a shorter time from onset to first call, and broader use of mobile intensive care units. Reperfusion therapy increased from 49.4% to 74.7%, driven by primary percutaneous coronary intervention (11.9% to 60.8%). Early use of recommended medications increased, particularly low-molecular-weight heparins and statins. Crude 30-day mortality decreased from 13.7% (95% CI, 12.0-15.4) to 4.4% (95% CI, 3.5-5.4), whereas standardized mortality decreased from 11.3% (95% CI, 9.5-13.2) to 4.4% (95% CI, 3.5-5.4). Multivariable analysis showed a consistent reduction in mortality from 1995 to 2010 after controlling for clinical characteristics in addition to the initial population risk score and use of reperfusion therapy, with odds mortality ratios of 0.39 (95%, 0.29-0.53, P Conclusion In France, the overall rate of cardiovascular mortality among patients with STEMI decreased from 1995 to 2010, accompanied by an increase in the proportion of women younger than 60 years with STEMI, changes in other population characteristics, and greater use of reperfusion therapy and recommended medications.

Role of the c subunit of the FO ATP synthase in mitochondrial permeability transition

Abstract: The term "mitochondrial permeability transition" (MPT) refers to an abrupt increase in the permeability of the inner mitochondrial membrane to low molecular weight solutes. Due to osmotic forces, MPT is paralleled by a massive influx of water into the mitochondrial matrix, eventually leading to the structural collapse of the organelle. Thus, MPT can initiate mitochondrial outer membrane permeabilization (MOMP), promoting the activation of the apoptotic caspase cascade as well as of caspase-independent cell death mechanisms. MPT appears to be mediated by the opening of the so-called "permeability transition pore complex" (PTPC), a poorly characterized and versatile supramolecular entity assembled at the junctions between the inner and outer mitochondrial membranes. In spite of considerable experimental efforts, the precise molecular composition of the PTPC remains obscure and only one of its constituents, cyclophilin D (CYPD), has been ascribed with a crucial role in the regulation of cell death. Conversely, the results of genetic experiments indicate that other major components of the PTPC, such as voltage-dependent anion channel (VDAC) and adenine nucleotide translocase (ANT), are dispensable for MPT-driven MOMP. Here, we demonstrate that the c subunit of the FO ATP synthase is required for MPT, mitochondrial fragmentation and cell death as induced by cytosolic calcium overload and oxidative stress in both glycolytic and respiratory cell models. Our results strongly suggest that, similar to CYPD, the c subunit of the FO ATP synthase constitutes a critical component of the PTPC.

Specific inulin-type fructan fibers protect against autoimmune diabetes by modulating gut immunity, barrier function, and microbiota homeostasis

Abstract: cope Dietary fibers capable of modifying gut barrier and microbiota homeostasis affect the progression of type 1 diabetes (T1D). Here, we aim to compare modulatory effects of inulin-type fructans (ITFs), natural soluble dietary fibers with different degrees of fermentability from chicory root, on T1D development in nonobese diabetic mice. Methods and results Female nonobese diabetic mice were weaned to long- and short-chain ITFs [ITF(l) and ITF(s), 5%] supplemented diet up to 24 weeks. T1D incidence, pancreatic-gut immune responses, gut barrier function, and microbiota composition were analyzed. ITF(l) but not ITF(s) supplementation dampened the incidence of T1D. ITF(l) promoted modulatory T-cell responses, as evidenced by increased CD25+Foxp3+CD4+ regulatory T cells, decreased IL17A+CD4+ Th17 cells, and modulated cytokine production profile in the pancreas, spleen, and colon. Furthermore, ITF(l) suppressed NOD like receptor protein 3 caspase-1-p20-IL-1β inflammasome in the colon. Expression of barrier reinforcing tight junction proteins occludin and claudin-2, antimicrobial peptides β-defensin-1, and cathelicidin-related antimicrobial peptide as well as short-chain fatty acid production were enhanced by ITF(l). Next-generation sequencing analysis revealed that ITF(l) enhanced Firmicutes/Bacteroidetes ratio to an antidiabetogenic balance and enriched modulatory Ruminococcaceae and Lactobacilli. Conclusion Our data demonstrate that ITF(l) but not ITF(s) delays the development of T1D via modulation of gut-pancreatic immunity, barrier function, and microbiota homeostasis.