Papers by Catherine Coirault
ACS Nano, Oct 27, 2022
The engineering of skeletal muscle tissue, a highly organized structure of myotubes, is promising... more The engineering of skeletal muscle tissue, a highly organized structure of myotubes, is promising for the treatment of muscle injuries and muscle diseases, for replacement or pharmacology research. Muscle tissue development involves differentiation of myoblasts into myotubes with parallel orientation, to ultimately form aligned myofibers, which is challenging to achieve on flat surfaces. In this work, we designed hydrogen-bonded tannic acid/collagen layer-by-layer (TA/COL LbL) nanofilms using a simple brushing method to address this issue. In comparison to films obtained by the dipping, brushed TA/COL films showed oriented COL fibers of 60 nm diameter along the brushing direction. Built at acidic pH due to COL solubility, TA/COL films released TA in physiological conditions with a minor loss of thickness. After characterization of COL fibers orientation, human myoblasts (C25CL48) were seeded on the oriented TA/COL film, ended by COL. After 12 days in a differentiation medium without any other supplement, human myoblasts were able to align on brushed TA/COL films and to differentiate into long aligned myotubes (from hundreds of nm up to 1.7 mm length) thanks to two distinct properties: (i) the orientation of COL fibers guiding myoblasts alignment, and (ii) the TA release favoring the differentiation. This simple and potent brushing process allows the development of anisotropic tissues in vitro which can be used for studies of drug discovery and screening or the replacement of damaged tissue.
HAL (Le Centre pour la Communication Scientifique Directe), 2006
RA; 37 patients with essential hypertension (EH) without rheumatic diseases and 26 healthy donors... more RA; 37 patients with essential hypertension (EH) without rheumatic diseases and 26 healthy donors. We evaluated anamnesis, blood pressure level (BPL), echocardiography data, endothelial vasodilation capacity (EVC), l-arginine plasma level. All patients were purely comparable in age (young and middle age), gender structure; RA with AH patients and EH patients-in BPL, anamnesis duration, SCORE-risk. No one of the observed persons had associated clinical states. Results: The mean number of CVR factors per person in RA patients was lower than in EH patients (P < 0.05) without important difference in the risk factors structure (compromised cardiovascular family history and abdominal obesity prevailed). However, RA patients with AH and with normal BPL compared to EH patients had higher left ventricular myocardial mass index (P < 0.05), lower EVC (P < 0.05) and lower larginine plasma level (P < 0.05). The concentric hypertrophy type (CHT) of left-ventricular remodeling prevailed in EH and RA and AH group; eccentric hypertrophy type-in RA with normal BPL. AH in RA correlated with risk factors presence (r = 0.32); anamnesis duration (r = 0.7); rheumatoid factor presence (r = 0.5); steroid intake (r = 0.32). Conclusion: AH and cardiovascular remodeling in RA is connected with RA course and conducted steroid therapy. Significant left-ventricular hypertrophy and unadaptable remodeling increases CVR, supposes heart failure development and demands cardioprotection in RA patients.
M S-medecine Sciences, 1998
HAL (Le Centre pour la Communication Scientifique Directe), Sep 1, 2017
Experimental Methods in Orthopaedic Biomechanics, 2017
Abstract Skeletal muscles are actuators that generate forces to move limbs, transfer load across ... more Abstract Skeletal muscles are actuators that generate forces to move limbs, transfer load across joints, and stabilize body position or posture. Muscle is organized into basic units of ascending size, namely, sarcomeres (i.e., main contractile units), which comprise the myofibrils (i.e., delicate strand-like filaments), which comprise the fibers (i.e., long, cylindrical multinucleated cells), which comprise the main muscle belly. Muscle's passive tension arises from elastic spring-like elements stretched beyond their resting length, while active tension is generated by processes within the sarcomere. Active tension is produced in different ways: concentric (i.e., muscle length is shortened), eccentric (i.e., muscle length is extended), isometric (i.e., muscle length is fixed), isotonic (i.e., muscle tension is fixed), isokinetic (i.e., muscle shortening or lengthening velocity is fixed), and isoinertial (i.e., muscle contraction encounters a fixed external resistance). To simplify experiments and computer models in orthopaedic biomechanics research, muscle action is often treated like a system of force vectors acting on limbs or joints. Yet, the magnitude and direction of these force vectors depend on muscle's intrinsic mechanical properties during contraction, especially the interrelationship between force, velocity, and length. Therefore, this chapter explains how to experimentally perform in vitro measurements of contraction force, velocity, and length of skeletal muscle, as well as how to analyze, present, and interpret results.
British Journal of Anaesthesia, 1998
Dantrolene is the only known effective treatment for malignant hyperthermia. However, its effects... more Dantrolene is the only known effective treatment for malignant hyperthermia. However, its effects on the myopathic diaphragm remain unknown. The effects of dantrolene 10 98 to 10 94 mol litre 91 on diaphragm muscle strips in normal (n:12) and myopathic hamsters (n:13) were investigated in vitro in response to tetanic stimulation. We studied contraction under isotonic and isometric conditions. Data are presented as mean (SD) percent of baseline. Dantrolene induced a negative inotropic effect in normal and myopathic hamsters but no significant difference was observed between groups (active force at 10 94 mol litre 91 : 34 (7) vs 32 (11) %; ns). We conclude that dantrolene induced a comparable negative inotropic effect on diaphragm muscle in normal and myopathic hamsters. (Br.
Anesthesia & Analgesia, 1999
European Journal of Translational Myology, 2017
The 14th Meeting of the Interuniversity Institute of Myology (IIM), October 12-15, 2017 - Assisi,... more The 14th Meeting of the Interuniversity Institute of Myology (IIM), October 12-15, 2017 - Assisi, Italy gathered together researchers from Italy, European and North-American countries to discuss recent results on muscle research. The program showcased keynote lectures from world-renowned international speakers presenting advances in muscle physiology, bioengineering, metabolism and therapeutics. Based on selection from submitted abstracts, participants presented their novel, unpublished results in seven oral communication and two poster sessions. Particular emphasis was devoted to young trainees. For example, trainees where directly involved in organizing a scientific session and three round tables tailored to the interests of their peers. The meeting attracted a broad audience from Italy, various European countries and from North America. It offered a unique opportunity to all researchers involved in the field of muscle biology to exchange ideas and foster scientific collaborations...
Cellular micro-environments reveal defective mechanosensing
European Respiratory Journal, 1999
The aim of this study was to determine cross-bridge number and kinetics in the diaphragm during f... more The aim of this study was to determine cross-bridge number and kinetics in the diaphragm during fatigue and early recovery. Experiments were conducted in isolated mouse diaphragm (n=10). The force of a single cross-bridge (P), the number of cross-bridges (m610 9. mm-2), the time cycle (tc) and the rate constants for cross-bridge attachment (f 1) and detachment (g 2) were calculated from the equations of A.F. Huxley. Following the fatigue protocol, peak isometric tension (Po) and maximum unloaded shortening velocity fell by 401% and 172%, respectively. In fatigued diaphragm, m fell by approximately 40% and returned to baseline after 10 min. When compared to baseline, g 2 fell in fatigued diaphragm and remained significantly lower during the 15min recovery period. In contrast, fatigue did not significantly modify P, f 1 , or tc. There was a strong linear relationship between Po and m (p<0.001, r=0.988). No relationship was observed between tc and g 2. These results indicate that changes in tension during fatigue and recovery run parallel to changes in the number of active cross-bridges, with no change in the force generated per cross-bridge. It is conceivable that fatigue durably impairs adenosine diphosphate release from the actomyosin complex without modifying the total duration of the cross-bridge cycle.
Journal of Applied Physiology, 2003
After extensive necrosis, progressive diaphragm muscle weakness in the mdx mouse is thought to re... more After extensive necrosis, progressive diaphragm muscle weakness in the mdx mouse is thought to reflect progressive replacement of contractile tissue by fibrosis. However, little has been documented on diaphragm muscle performance at the stage at which necrosis and fibrosis are limited. Diaphragm morphometric characteristics, muscle performance, and cross-bridge (CB) properties were investigated in 6-wk-old control (C) and mdx mice. Compared with C, maximum tetanic tension and shortening velocity were 37 and 32% lower, respectively, in mdx mice (each P < 0.05). The total number of active CB per millimeter squared (13.0 ± 1.2 vs. 18.4 ± 1.7 × 109/mm2, P < 0.05) and the CB elementary force (8.0 ± 0.2 vs. 9.0 ± 0.1 pN, P < 0.01) were lower in mdx than in C. The time cycle duration was lower in mdx than in C (127 ± 18 vs. 267 ± 61 ms, P < 0.05). Percentages of fiber necrosis represented 2.8 ± 0.6% of the total muscle fibers, and collagen surface area occupied 3.6 ± 0.7% in md...
ance in diaphragm muscle of the cardiomyopathic Syrian
Cells, 2021
Skeletal muscle is composed of multinucleated, mature muscle cells (myofibers) responsible for co... more Skeletal muscle is composed of multinucleated, mature muscle cells (myofibers) responsible for contraction, and a resident pool of mononucleated muscle cell precursors (MCPs), that are maintained in a quiescent state in homeostatic conditions. Skeletal muscle is remarkable in its ability to adapt to mechanical constraints, a property referred as muscle plasticity and mediated by both MCPs and myofibers. An emerging body of literature supports the notion that muscle plasticity is critically dependent upon nuclear mechanotransduction, which is transduction of exterior physical forces into the nucleus to generate a biological response. Mechanical loading induces nuclear deformation, changes in the nuclear lamina organization, chromatin condensation state, and cell signaling, which ultimately impacts myogenic cell fate decisions. This review summarizes contemporary insights into the mechanisms underlying nuclear force transmission in MCPs and myofibers. We discuss how the cytoskeleton a...
American journal of physiology. Heart and circulatory physiology, 2007
This study was designed to determine the effects of PPARalpha lack on cardiac mechanical performa... more This study was designed to determine the effects of PPARalpha lack on cardiac mechanical performance and to identify potential intracellular mechanisms linking PPARalpha pathway deficiency to cardiac contractile dysfunction. Echocardiography, ex vivo papillary muscle assays, and in vitro motility assays were used to assess global, intrinsic ventricular muscle performance and myosin mechanical properties, respectively, in PPARalpha(-/-) and age-matched wild-type mice. Three-nitrotyrosine formation and 4-hydroxy-2-nonenal protein-adducts, both markers of oxidative damage, were analyzed by Western blot analysis and immunolabeling. Radical scavenging capacity was analyzed by measuring protein levels and/or activities of the main antioxidant enzymes, including catalase, glutathione peroxidase, and manganese and copper-zinc superoxide dismutases. Echocardiographic left ventricular fractional shortening in PPARalpha(-/-) was 16% lower than that in wild-type. Ex vivo left ventricular papill...
Emerin is a nuclear envelope protein that contributes to genome organization and cell 13 mechanic... more Emerin is a nuclear envelope protein that contributes to genome organization and cell 13 mechanics. Through its N-terminal LEM-domain, emerin interacts with the DNA-binding protein 14 Barrier-to-Autointegration (BAF). Emerin also binds to members of the Linker of the Nucleoskeleton 15 and Cytoskeleton (LINC) complex. Mutations in the gene encoding emerin are responsible for the 16 majority of cases of X-linked Emery-Dreifuss Muscular Dystrophy (X-EDMD). Most of these 17 mutations lead to an absence of emerin. A few missense and short deletion mutations in the 18 disordered region of emerin are also associated with X-EDMD. More recently, missense and short 19 deletion mutations P22L, ∆K37 and T43I were discovered in emerin LEM-domain, associated with 20 isolated atrial cardiac defects (ACD). Here we reveal which defects, at both molecular and cellular 21 levels, are elicited by these LEM-domain mutations. Whereas ΔK37 mutation impairs correct folding 22 of the LEM-domain, P22L and T4...
Background Laminopathies are a clinically heterogeneous group of disorders caused by mutations in... more Background Laminopathies are a clinically heterogeneous group of disorders caused by mutations in the LMNA gene, which encodes the nuclear envelope proteins lamins A and C. The most frequent diseases associated with LMNA mutations are characterized by skeletal and cardiac involvement, and include autosomal dominant Emery-Dreifuss muscular dystrophy (EDMD), limb-girdle muscular dystrophy type 1B, and LMNA-related congenital muscular dystrophy (LMNA-CMD). Although the exact pathophysiological mechanisms responsible for LMNA-CMD are not yet understood, severe contracture and muscle atrophy suggest that impair skeletal muscle growth may contribute to the disease severity. Methods We used human muscle stem cells (MuSCs) carrying 4 different LMNA mutations and two mouse models of muscle laminopathies, representing a spectrum of disease severity, to investigate the ability of skeletal muscle to differentiate and to hypertrophy in response to mechanical challenges. We extended these finding...
Journal of Molecular and Cellular Cardiology, 2007
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Papers by Catherine Coirault