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This is supplementary data for the article : " COPD is deleterious for pericytes: implications during training induced angiogenesis in skeletal muscle", accepted in AJP - Heart and circulatory physiology.

Additional file 1. Questionnaire about the clinical reasoning sessions and diagnostic test learning.

International audience

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant disease characterized by progressive weakness and atrophy of specific skeletal muscles. Despite major progress in the understanding of the genetic basis of FSHD, the exact mechanisms that lead to FSHD defects are not completely understood and no curative treatment is available. However, there is growing evidence that oxidative stress may contribute to FSHD pathology. We recently reported that reduced physical performance in patients with FSHD is associated with important redox unbalance and oxidative stress in blood. Hence, we hypothesized that insufficient intake of antioxidant vitamins and minerals may reduce the body capacity to regulate free radical insults, leading to a condition known as oxidative stress that could affect muscle function performance in patients with FSHD. We thus conducted a pilot randomized double-blind placebo-controlled study to test whether oral administration of vitamins and minerals could improve the physical performance of patients with FSHD. The results of this randomized double-blind placebo-controlled trial show that supplementation with vitamin C, vitamin E (as alpha tocopherol), zinc gluconate and selenomethionine in patients with FSHD significantly improves the maximal voluntary contraction and endurance of both quadriceps by enhancing the antioxidants defences and reducing oxidative stress.

Introduction When confronted to stress or pathological conditions, the mitochondria overproduce reactive species that participate in the cellular dysfunction. These organelles are however difficult to target with antioxidants. A feature of mitochondria that can be used for this is the negatively charged compartments they form. Most of mitochondrion-targeting antioxidants are therefore cationic synthetic molecules. Our hypothesis is that such mitochondriotropic traits might also exists in natural molecules. Aim We tested here whether sinapine, a natural phenolic antioxidant-bearing a permanent positive charge, can target mitochondria to modulate mitochondrial oxidative stress. Methods Experiments were performed in-vitro, in-cellulo, ex-vivo, and in-vivo, using cardiac tissue. The sinapic acid -lacking the positively-charged-choline-moiety present in sinapine-was used as a control. Sinapine entry into mitochondria was investigated in-vivo and in cardiomyocytes. We used fluorescent probes to detect cytosolic (H2DCFDA) and mitochondrial (DHR123) oxidative stress on cardiomyocytes induced with either hydrogen peroxide (H2O2) or antimycin A, respectively. Finally, ROS production was measured with DHE 10 min after ischemia-reperfusion (IR) on isolated heart, treated or not with sinapine, sinapic acid or with a known synthetic mitochondrion-targeted antioxidant (mitoTempo). Results We detected the presence of sinapine within mitochondria in-vitro, after incubation of isolated cardiomyocytes, and in-vivo, after oral treatment. The presence of sinapic acid was not detected in the mitochondria. Both the sinapine and the sinapic acid limited cytosolic oxidative stress in response to H2O2. Only sinapine was able to blunt oxidative stress resulting from antimycin A-induced mtROS. Both mitoTempo and sinapine improved cardiac functional recovery following IR. This was associated with lower ROS production within the cardiac tissue. Conclusion Sinapine, a natural cationic hydrophilic phenol, commonly and substantially found in rapeseed species, effectively (i) enters within the mitochondria, (ii) selectively decreases the level of mitochondrial oxidative stress and, (iii) efficiently limits ROS production during cardiac ischemia-reperfusion., Graphical abstract Image 1, Highlights • Sinapine, a choline ester of sinapic acid, enters within mitochondria, whereas sinapic acid does not. • Sinapine reduces mitochondrial oxidative stress, whereas sinapic acid does not. • Sinapine reduces cardiac reactive oxygen species production during ischemia-reperfusion, whereas sinapic does not.

The mechanisms leading to skeletal limb muscle dysfunction in chronic obstructive pulmonary disease (COPD) have not been fully elucidated. Exhausted muscle regenerative capacity of satellite cells has been evocated, but the capacity of satellite cells to proliferate and differentiate properly remains unknown. Our objectives were to compare the characteristics of satellite cells derived from COPD patients and healthy individuals, in terms of proliferative and differentiation capacities, morphological phenotype and atrophy/hypertrophy signalling, and oxidative stress status. Therefore, we purified and cultivated satellite cells from progressively frozen vastus lateralis biopsies of eight COPD patients and eight healthy individuals. We examined proliferation parameters, differentiation capacities, myotube diameter, expression of atrophy/hypertrophy markers, oxidative stress damages, antioxidant enzyme expression and cell susceptibility to H2 O2 in cultured myoblasts and/or myotubes. Proliferation characteristics and commitment to terminal differentiation were similar in COPD patients and healthy individuals, despite impaired fusion capacities of COPD myotubes. Myotube diameter was smaller in COPD patients (P = 0.015), and was associated with a higher expression of myostatin (myoblasts: P = 0.083; myotubes: P = 0.050) and atrogin-1 (myoblasts: P = 0.050), and a decreased phospho-AKT/AKT ratio (myoblasts: P = 0.022). Protein carbonylation (myoblasts: P = 0.028; myotubes: P = 0.002) and lipid peroxidation (myotubes: P = 0.065) were higher in COPD cells, and COPD myoblasts were significantly more susceptible to oxidative stress. Thus, cultured satellite cells from COPD patients display characteristics of morphology, atrophic signalling and oxidative stress similar to those described in in vivo COPD skeletal limb muscles. We have therefore demonstrated that muscle alteration in COPD can be studied by classical in vitro cellular models.

International audience; Defects in insulin sensitivity are associated with metabolic inflexibility and obesity albeit some obese subjects have preserved insulin sensitivity. A decrease in lipid oxidation during exercise can be found in obesity and type 2 diabetes. This lipid oxidation capacity has been found to be associated in healthy or overweight subjects with insulin sensitivity and mitochondrial function. Thus, we aimed at delineate the interrelationships among the maximal ability to oxidize lipids at exercise (LIPOXmax) insulin sensitivity and mitochondrial function in middle-aged obese men with different levels of insulin sensitivity.After an overnight fast, twenty middle-aged male obese subjects performed: a maximal incremental exercise test allowing the determination of LIPOXmax, two days after a measurement of insulin sensitivity and two days after a muscle biopsy for mitochondrial respiration.According to the minimal model, we found 9 insulin-resistant and 11 insulin-sensitive middle-aged obese men. LIPOXmax (expressed as power intensity) and whole-body insulin sensitivity are significantly correlated in obese insulin-sensitive but not in insulin-resistant obese men. LIPOXmax and insulin sensitivity are correlated to mitochondrial pyruvate oxidation and mitochondrial density. Multivariate analysis indicates that insulin sensitivity is statistically better explained by the LIPOXmax which is in turn better explained by the mitochondrial function parameter Vmax/V0 pyruvate.Thus, insulin sensitivity, mitochondrial function and the ability of muscle to oxidize lipids during exercise are three closely correlated parameters in middle-aged male obese insulin-sensitive patients.

International audience; The endothelin system has emerged as a novel target for the treatment of diabetic nephropathy. Endothelin-1 promotes mesangial cell proliferation and sclerosis. However, no direct pathogenic effect of endothelin-1 on podocytes has been shown in vivo and endothelin-1 signaling in podocytes has not been investigated. This study investigated endothelin effects in podocytes during experimental diabetic nephropathy. Stimulation of primary mouse podocytes with endothelin-1 elicited rapid calcium transients mediated by endothelin type A receptors (ETARs) and endothelin type B receptors (ETBRs). We then generated mice with a podocyte-specific double deletion of ETAR and ETBR (NPHS2-Cre3Ednra lox/lox 3Ednrb lox/lox [Pod-ETRKO]). In vitro, treatment with endothelin-1 increased total b-catenin and phospho-NF-kB expression in wild-type glomeruli, but this effect was attenuated in Pod-ETRKO glomeruli. After streptozotocin injection to induce diabetes, wild-type mice developed mild diabetic nephropathy with microalbuminuria, mesangial matrix expansion, glomerular basement membrane thickening, and podocyte loss, whereas Pod-ETRKO mice presented less albuminuria and were completely protected from glomerulosclerosis and podocyte loss, even when uninephrectomized. Moreover, glomeruli from normal and diabetic Pod-ETRKO mice expressed substantially less total b-catenin and phospho-NF-kB compared with glomeruli from counterpart wild-type mice. This evidence suggests that endothelin-1 drives development of glomerulosclerosis and podocyte loss through direct activation of endo-thelin receptors and NF-kB and b-catenin pathways in podocytes. Notably, both the expression and function of the ETBR subtype were found to be important. Furthermore, these results indicate that activation of the endothelin-1 pathways selectively in podocytes mediates pathophysiologic crosstalk that influences mesangial architecture and sclerosis.

Intensive physical training may have a sport-dependent effect on bone mass acquisition. This cross-sectional study evaluated bone mass acquisition in girls practicing sports that put different mechanical loads on bone.Eighty girls from 10.7 to 18.0 years old (mean 13.83 ± 1.97) were recruited: 20 artistic gymnasts (AG; high-impact activity), 20 rhythmic gymnasts (RG; medium-impact activity), 20 swimmers (SW, no-impact activity), and 20 age-matched controls (CON; leisure physical activity3h/wk). Areal bone mineral density (aBMD) was determined using DEXA. Hip structural analysis applied at the femur evaluated cross-sectional area (CSA, cm(2)), section modulus (Z, cm(3)), and buckling ratio. Bone turnover markers and OPG/RANKL levels were analyzed.AG had higher aBMD than SW and CON at all bone sites and higher values than RG in the lumbar spine and radius. RG had higher aBMD than SW and CON only in the femoral region. CSA and mean cortical thickness were significantly higher and the buckling ratio was significantly lower in both gymnast groups compared with SW and CON. In RG only, endocortical diameter and width were reduced, while Z was only increased in AG compared with SW and CON. Reduced bone remodeling was observed in RG compared with AG only when groups were subdivided according to menarcheal status. All groups showed similar OPG concentrations, while RANKL concentrations increased with age and were decreased in SW.High-impact activity clearly had a favorable effect on aBMD and bone geometry during the growth period, although the bone health benefits seem to be more marked after menarche.

Background Obese patients are at risk for developing atelectasis and ARDS. Prone position (PP) may reduce atelectasis, and it improves oxygenation and outcome in severe hypoxemic patients with ARDS, but little is known about its effect in obese patients with ARDS. Methods Morbidly obese patients (BMI ≥ 35 kg/m 2 ) with ARDS (Pao 2 /Fio 2 ratio ≤ 200 mm Hg) were matched to nonobese (BMI 2 ) patients with ARDS in a case-control clinical study. The primary end points were safety and complications of PP; the secondary end points were the effect on oxygenation (Pao 2 /Fio 2 ratio at the end of PP), length of mechanical ventilation and ICU stay, nosocomial infections, and mortality. Results Between January 2005 and December 2009, 149 patients were admitted for ARDS. Thirty-three obese patients were matched with 33 nonobese patients. Median (25th-75th percentile) PP duration was 9 h (6-11 h) in obese patients and 8 h (7-12 h) in nonobese patients ( P = .28). We collected 51 complications: 25 in obese and 26 in nonobese patients. The number of patients with at least one complication was similar across groups (n = 10, 30%). Pao 2 /Fio 2 ratio increased significantly more in obese patients (from 118 ± 43 mm Hg to 222 ± 84 mm Hg) than in nonobese patients (from 113 ± 43 mm Hg to 174 ± 80 mm Hg; P = .03). Length of mechanical ventilation, ICU stay, and nosocomial infections did not differ significantly, but mortality at 90 days was significantly lower in obese patients (27% vs 48%, P Conclusions PP seems safe in obese patients and may improve oxygenation more than in nonobese patients. Obese patients could be a subgroup of patients with ARDS who may benefit the most of PP.

Objective: To characterize pulmonary hemodynamic changes in relation to lung injury at 2 time points [48 h (H48) and 168 h (H168)] after pneumonectomy under intraoperative protective ventilation in order to improve postpneumonectomy pulmonary edema (PPE) prevention. Method: Fifteen pigs (25 ± 1.9 kg) were randomly allocated to nonsurgical (control, n = 5) and surgical (H48 and H168) groups. A left pneumonectomy under volume-controlled one-lung ventilation (OLV) (low tidal volume, positive end-expiratory pressure = 4 cm H2O, inspired oxygen fraction = 50%) was performed in surgical animals. Mean pulmonary artery pressure (MPAP) and pulmonary artery occlusion pressure were recorded. Pulmonary vascular resistance (PVR) was calculated. Pulmonary damage score (PDS) and bronchoalveolar albumin level were evaluated. Data were collected after induction (T0), after OLV (T1), after left pneumonectomy (T2), and at H48 or H168 (T3). Results: Pneumonectomy caused precapillary pulmonary arterial hypertension (PAH) measured at T3 H48 (36.2 ± 3.67 mm Hg). PAH was delayed temporarily (both after OLV and after pneumonectomy) (p < 0.001), and linked with PVR (r = 0.93; p < 0.05). PDS and bronchoalveolar albumin level varied with MPAP (r = 0.76; p < 0.001 and r = 0.55; p < 0.05). Conclusion: Given that PAH is delayed and related to PVR increase, indicating secondary pulmonary vascular bed adaptation limits, pharmacological treatment should focus on a delayed failure in pulmonary capacitance in patients at risk of PPE.

Facioscapulohumeral muscular dystrophy (FSHD) is one of the most frequent hereditary muscle disorders. It is linked to contractions of the D4Z4 repeat array in 4q35. We have characterized the double homeobox 4 (DUX4) gene in D4Z4 and its mRNA transcribed from the distal D4Z4 unit to a polyadenylation signal in the flanking pLAM region. It encodes a transcription factor expressed in FSHD but not healthy muscle cells which initiates a gene deregulation cascade causing differentiation defects, muscle atrophy and oxidative stress. PITX1 was the first identified DUX4 target and encodes a transcription factor involved in muscle atrophy. DUX4 was found expressed in only 1/1000 FSHD myoblasts. We have now shown it was induced upon differentiation and detected in about 1/200 myotube nuclei. The DUX4 and PITX1 proteins presented staining gradients in consecutive myonuclei which suggested a diffusion as known for other muscle nuclear proteins. Both protein half-lifes were regulated by the ubiquitin-proteasome pathway. In addition, we could immunodetect the DUX4 protein in FSHD muscle extracts. As a model, we propose the DUX4 gene is stochastically activated in a small number of FSHD myonuclei. The resulting mRNAs are translated in the cytoplasm around an activated nucleus and the DUX4 proteins diffuse to adjacent nuclei where they activate target genes such as PITX1. The PITX1 protein can further diffuse to additional myonuclei and expand the transcriptional deregulation cascade initiated by DUX4. Together the diffusion and the deregulation cascade would explain how a rare protein could cause the muscle defects observed in FSHD.

International audience; Background: Although the benefits of comprehensive pulmonary rehabilitation have been demonstrated in patients with COPD, the effects of exercise sessions within self-management programs remain unclear. We hypothesized that 8 supervised exercise sessions incorporated in a 1-month self-management education program in COPD patients would be effective to improve health outcomes and to reduce direct medical costs after one year, compared to usual care. Methods: In this randomized controlled trial, 38 moderate-to-severe COPD patients were assigned either to an intervention group or to a usual care group. The hospital-based intervention program provided a combination of 8 sessions of supervised exercise with 8 self-management education sessions over a 1-month period. The primary end-point was the 6-min walking distance (6MWD), with secondary outcomes being health-related quality of life (HRQoL) e using the St. George’s Respiratory Questionnaire (SGRQ) and Nottingham Health Profile (NHP), maximal exercise capacity and healthcare utilization. Data were collected before and one year after the program.Results: After 12 months, we found statistically significant between-group differences in favor of the intervention group in 6MWD (þ50.5 m (95%CI, 2 to 99), in two domains of NHP (energy, 19.8 ( 38 to 1); emotional reaction, e10.4 ( 20 to 0)); in SGRQ-symptoms ( 14.0 ( 23 to 5)), and in cost of COPD medication ( 480.7 V (CI, 891 to 70) per patient per year).Conclusion: The present hospital-based intervention combining supervised exercise with self- management education provides significant improvements in patient’s exercise tolerance and HRQoL, and significant decrease of COPD medication costs, compared to usual care.

Background Neurally adjusted ventilatory assist (NAVA) is a new mode of mechanical ventilation that delivers ventilatory assist in proportion to the electrical activity of the diaphragm. This study aimed to compare the ventilatory and gas exchange effects between NAVA and pressure support ventilation (PSV) during the weaning phase of critically ill patients who required mechanical ventilation subsequent to surgery. Methods Fifteen patients, the majority of whom underwent abdominal surgery, were enrolled. They were ventilated with PSV and NAVA for 24 h each in a randomized crossover order. The ventilatory parameters and gas exchange effects produced by the two ventilation modes were compared. The variability of the ventilatory parameters was also evaluated by the coefficient of variation (SD to mean ratio). Results Two patients failed to shift to NAVA because of postoperative bilateral diaphragmatic paralysis, and one patient interrupted the study because of worsening of his sickness. In the other 12 cases, the 48 h of the study protocol were completed, using both ventilation modes, with no signs of intolerance or complications. The Pao2/Fio2 (mean ± SD) ratio in NAVA was significantly higher than with PSV (264 ± 71 vs. 230 ± 75 mmHg, P < 0.05). Paco2 did not differ significantly between the two modes. The tidal volume (median [interquartile range]) with NAVA was significantly lower than with PSV (7.0 [6.4-8.6] vs. 6.5 [6.3-7.4] ml/kg predicted body weight, P < 0.05).Variability of insufflation airway pressure, tidal volume, and minute ventilation were significantly higher with NAVA than with PSV. Electrical activity of the diaphragm variability was significantly lower with NAVA than with PSV. Conclusions Compared with PSV, respiratory parameter variability was greater with NAVA, probably leading in part to the significant improvement in patient oxygenation.

Patients with Duchenne muscular dystrophy (DMD) and mdx mice, devoid of dystrophin proteins, show altered ionic homeostasis. To clarify dystrophin's involvement in the central control of osmotic stimuli, we investigated the effect of the disruption of Dp71, the major form of dystrophin in the brain, on the hypothalamoneurohypophysis system (HNHS) osmoregulatory response. Dp71 and Dp140 are the principal DMD gene products in the supraoptic nucleus (SON) and neurohypophysis (NH). They are present in astrocyte and pituicyte end-feet, suggesting involvement in both intrinsic osmosensitivity of the SON and vasopressin (AVP) release from the NH. In Dp71-null mice, the cellular distribution of Dp140 was modified, this protein being detected on the membrane of magnocellular soma. The plasma osmolality of Dp71-null mice was lower than that of wild-type mice under normal conditions, and this difference was maintained after salt loading, indicating a change in the set point for osmoregulation in the absence of Dp71. The increase in AVP levels detected in the SON and NH of the wild-type was not observed in Dp71-null mice following salt loading, and the increase in AVP mRNA levels in the SON was smaller in Dp71-null than in wild-type mice. This suggests that Dp71 may be involved in the functional activity of the HNHS. Its astrocyte end-feet localization emphasizes the importance of neuronal–vascular–glial interactions for the central detection of osmolality. In the SON, Dp71 may be involved in osmosensitivity and definition of the “osmostat,” whereas, in the neurohypopohysis, it may be involved in fine-tuning AVP release. © 2009 Wiley-Liss, Inc.

International audience; Little is known on the metabolic profile of lung tumors and the reminiscence of embryonic features. Herein, we determined the bioenergetic profiles of human fibroblasts taken from lung epidermoid carcinoma (HLF-a) and fetal lung (MRC5). We also analysed human lung tumors and their surrounding healthy tissue from four patients with adenocarcinoma. On these different models, we measured functional parameters (cell growth rates in oxidative and glycolytic media, respiration, ATP synthesis and PDH activity) as well as compositional features (expression level of various energy proteins and upstream transcription factors). The results demonstrate that both the lung fetal and cancer cell lines produced their ATP predominantly by glycolysis, while oxidative phosphorylation was only capable of poor ATP delivery. This was explained by a decreased mitochondrial biogenesis caused by a lowered expression of PGC1␣ (as shown by RT-PCR and Western blot) and mtTFA. Consequently, the relative expression of glycolytic versus OXPHOS markers was high in these cells. Moreover, the re-activation of mitochondrial biogenesis with resveratrol induced cell death specifically in cancer cells. A consistent reduction of mitochondrial biogenesis and the subsequent alteration of respiratory capacity was also observed in lung tumors, associated with a lower expression level of bcl2. Our data give a better characterization of lung cancer cells' metabolic alterations which are essential for growth and survival. They designate mitochondrial biogenesis as a possible target for anti-cancer therapy.

International audience; Objective: To determined whether the implementation of an intubation management protocol leads to the reduction of intubation-related complications in the intensive care unit (ICU). Design: Two-phase, prospective, multicenter controlled study. Setting: Three medical-surgical ICUs in two university hospitals. Patients: Two hundred three consecutive ICU patients required 244 intubations. Interventions: All intubations performed during two consecutive phases (a 6-month quality control phase followed by a 6-month intervention phase based on the implementation of an ICU intubation bundle management protocol) were evaluated. The ten bundle components were: preoxygenation with noninvasive positive pressure ventilation , presence of two operators, rapid sequence induction, cricoid pressure, capnography, protective ventilation, fluid loading, preparation and early administration of sedation and vasopressor use if needed. Measurements and main results: The primary end points were the incidence of life-threatening complications occurring within 60 min after intubation (cardiac arrest or death, severe cardiovascular collapse and hypoxemia). Other complications (mild to moderate) were also evaluated. Baseline characteristics, including demographic data and reason for intubation (mainly acute respiratory failure), were similar in the two phases. The intubation procedure in the intervention phase (n = 121) was associated with significant decreases in both life-threatening complications (21 vs. 34%, p = 0.03) and other complications (9 vs. 21%, p = 0.01) compared to the control phase (n = 123). Conclusions: The implementation of an intubation management protocol can reduce immediate severe life-threatening complications associated with intubation of ICU patients.

International audience; The gastrointestinal tract develops from a simple and uniform tube into a complex organ with specific differentiation patterns along the anterior-posterior and dorso-ventral axes of asymmetry. It is derived from all three germ layers and their cross-talk is important for the regulated development of fetal and adult gastrointestinal structures and organs. Signals from the adjacent mesoderm are essential for the morphogenesis of the overlying epithelium. These mesenchymal-epithelial interactions govern the development and regionalization of the different gastrointestinal epithelia and involve most of the key morphogens and signaling pathways, such as the Hedgehog , BMPs, Notch, WNT, HOX, SOX and FOXF cascades. Moreover, the mechanisms underlying mesenchyme differentiation into smooth muscle cells influence the regionalization of the gastrointestinal epithelium through interactions with the enteric nervous system. In the neonatal and adult gastrointestinal tract, mesenchymal-epithelial interactions are essential for the maintenance of the epithelial regionalization and digestive epithelial homeostasis. Disruption of these interactions is also associated with bowel dysfunction potentially leading to epithelial tumor development. In this review, we will discuss various aspects of the mesenchymal-epithelial interactions observed during digestive epithelium development and differentiation and also during epithelial stem cell regeneration.

We offer a brief overview of recent advances in the instrumentation of dedicated cardiac gamma cameras. We focus on the expected benefits in the fields of classical myocardial perfusion imaging and gated blood-pool SPECT. We also report some preliminary results regarding two active research topics at Montpellier University Hospital: quantification of myocardial perfusion reserve using dynamic SPECT, and detection of trigger zones after myocardial infraction using a 201 Tl/ 123 I-MIBG dual isotope protocol, Nous proposons ici une synthèse succincte des avancées récentes en termes d'instrumentation des gamma-caméras orientées cardiologie. Y sont détaillées, en particulier, les possibilités offertes en imagerie de perfusion myocardique classique et en tomographie cavitaire. Y sont, par ailleurs, rapportés les résultats préliminaires relatifs à deux thématiques de recherche actives au CHU de Montpellier portant sur la quantification de réserve de perfusion myocardique par SPECT dynamique et sur la détection de zones gâchettes en post-SCA précoce par protocole double isotope 201 Tl/ 123 I-MIBG.

To investigate the physiological diversity in the regulation and control of mitochondrial oxidative phosphorylation, we determined the composition and functional features of the respiratory chain in muscle, heart, liver, kidney, and brain. First, we observed important variations in mitochondrial content and infrastructure via electron micrographs of the different tissue sections. Analyses of respiratory chain enzyme content by Western blot also showed large differences between tissues, in good correlation with the expression level of mitochondrial transcription factor A and the activity of citrate synthase. On the isolated mitochondria, we observed a conserved molar ratio between the respiratory chain complexes and a variable stoichiometry for coenzyme Q and cytochrome c, with typical values of [1–1.5]:[30–135]:[3]:[9–35]:[6.5–7.5] for complex II:coenzyme Q:complex III:cytochrome c:complex IV in the different tissues. The functional analysis revealed important differences in maximal velocities of respiratory chain complexes, with higher values in heart. However, calculation of the catalytic constants showed that brain contained the more active enzyme complexes. Hence, our study demonstrates that, in tissues, oxidative phosphorylation capacity is highly variable and diverse, as determined by different combinations of 1) the mitochondrial content, 2) the amount of respiratory chain complexes, and 3) their intrinsic activity. In all tissues, there was a large excess of enzyme capacity and intermediate substrate concentration, compared with what is required for state 3 respiration. To conclude, we submitted our data to a principal component analysis that revealed three groups of tissues: muscle and heart, brain, and liver and kidney.

Mechanisms that regulate attachment of the scaffold/matrix attachment regions (S/MARs) to the nuclear matrix remain largely unknown. We have studied the effect of simple sequence length polymorphism (SSLP), DNA methylation and chromatin organization in an S/MAR implicated in facioscapulohumeral dystrophy (FSHD), a hereditary disease linked to a partial deletion of the D4Z4 repeat array on chromosome 4q. This FSHD-related nuclear matrix attachment region (FR-MAR) loses its efficiency in myoblasts from FSHD patients. Three criteria were found to be important for high-affinity interaction between the FR-MAR and the nuclear matrix: the presence of a specific SSLP haplotype in chromosomal DNA, the methylation of one specific CpG within the FR-MAR and the absence of histone H3 acetylated on lysine 9 in the relevant chromatin fragment.

International audience; Background:: Diaphragm and psoas are affected during sepsis in animal models. Whether diaphragm or limb muscle is preferentially affected during sepsis in the critically ill remains unclear.Methods:: Retrospective secondary analysis study including 40 patients, comparing control (n = 17) and critically ill patients, with (n = 14) or without sepsis (n = 9). Diaphragm volume, psoas volume, and cross-sectional area of the skeletal muscles at the third lumbar vertebra were measured during intensive care unit (ICU) stay using tridimensional computed tomography scan volumetry. Diaphragm strength was evaluated using magnetic phrenic nerve stimulation. The primary endpoint was the comparison between diaphragm and peripheral muscle volume kinetics during the ICU stay among critically ill patients, with or without sepsis.Results:: Upon ICU admission, neither diaphragm nor psoas muscle volumes were significantly different between critically ill and control patients (163 ± 53 cm3 vs. 197 ± 82 cm3 for the diaphragm, P = 0.36, and 272 ± 116 cm3 vs. to 329 ± 166 cm3 for the psoas, P = 0.31). Twenty-five (15 to 36) days after admission, diaphragm volume decreased by 11 ± 13% in nonseptic and by 27 ± 12% in septic patients, P = 0.01. Psoas volume decreased by 11 ± 10% in nonseptic and by 19 ± 13% in septic patients, P = 0.09. Upon ICU admission, diaphragm strength was correlated with diaphragm volume and was lower in septic (6.2 cm H2O [5.6 to 9.3]) than that in nonseptic patients (13.2 cm H2O [12.3 to 15.6]), P = 0.01.Conclusions:: During the ICU stay, both diaphragm and psoas volumes decreased. In septic patients, the authors report for the first time in humans preferential diaphragm atrophy compared with peripheral muscles.

Single studies of video laryngoscopy (VL) use for airway management in intensive care unit (ICU) patients have produced controversial findings. The aim of this study was to critically review the literature to investigate whether VL reduces difficult orotracheal intubation (OTI) rate, first-attempt success, and complications related to intubation in ICU patients, compared to standard therapy, defined as direct laryngoscopy (DL). We performed a systematic review and meta-analysis of randomized controlled trials, as well as prospective and retrospective observational studies, by searching PubMed, EMBASE, and bibliographies of articles retrieved. We screened for relevant studies that enrolled adults in whom the trachea was intubated in the ICU and compared VL to DL. We included studies reporting at least one clinical outcome of interest to perform a meta-analysis. We generated pooled odd ratios (OR) across studies. The primary outcome measure was difficult OTI. The secondary outcomes were first-attempt success, Cormack 3/4 grades, and complications related to intubation (severe hypoxemia, severe cardiovascular collapse, airway injury, esophageal intubation). Nine trials with a total of 2,133 participants (1,067 in DL and 1,066 in VL) were included in the current analysis. Compared to DL, VL reduced the risk of difficult OTI [OR 0.29 (95 % confidence interval (CI) 0.20-0.44, p < 0.001)], Cormack 3/4 grades [OR 0.26 (95 % CI 0.17-0.41, p < 0.001)], and esophageal intubation [0.14 (95 % CI 0.02-0.81, p = 0.03)] and increased the first-attempt success [OR 2.07 (95 % CI 1.35-3.16, p < 0.001)]. No statistically significant difference was found for severe hypoxemia, severe cardiovascular collapse or airway injury. These results suggest that VL could be useful in airway management of ICU patients.

Background: Acute transverse myelitis (ATM) in children is a rare and often severe disease for which there are few known prognostic factors, particularly the subsequent risk of multiple sclerosis (MS) diagnosis. Objectives: To determine the clinical course and prognostic factors after a first episode of ATM in children. Methods: Thirty children below 16 years of age diagnosed with a first neurological episode of ATM were included retrospectively. Clinical evaluation, treatment, laboratory, and MRI data were collected. Results: Median age at onset was 11 years (range 3–15 years). Follow-up data were available for a median of 4 years (range 0.5–16.7 years). Five patients subsequently had a diagnosis of MS (17%), which was associated with acute partial transverse myelitis (odds ratio 5; 95% confidence interval 2.3–11), with a 60% probability of having a relapse at five years ( p < 0.01). The 2011 Verhey criteria correctly identified MS in children with the highest specificity (96%) and sensitivity (80%). Conclusion: Acute partial transverse myelitis and brain MRI abnormalities at initial presentation are significantly predictive of a subsequent diagnosis of MS in children with ATM. These findings suggest that closer brain MRI monitoring after acute partial transverse myelitis might make the earlier introduction of disease-modifying therapies possible.

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International audience; Quantitative spatio-temporal characterization of protein interactions in living cells remains a major challenge facing modern biology. We have investigated in living neurons the spatial dependence of the stoichiometry of interactions between two core proteins of the N-methyl-D-aspartate (NMDA)-receptor-associated scaffolding complex, GKAP (also known as DLGAP1) and DLC2 (also known as DYNLL2), using a novel variation of fluorescence fluctuation microscopy called two-photon scanning number and brightness (sN&B). We found that dimerization of DLC2 was required for its interaction with GKAP, which, in turn, potentiated GKAP selfassociation. In the dendritic shaft, the DLC2-GKAP heterooligomeric complexes were composed mainly of two DLC2 and two GKAP monomers, whereas, in spines, the hetero-complexes were much larger, with an average of ,16 DLC2 and ,13 GKAP monomers. Disruption of the GKAP-DLC2 interaction strongly destabilized the oligomers, decreasing the spine-preferential localization of GKAP and inhibiting NMDA receptor activity. Hence, DLC2 serves a hub function in the control of glutamatergic transmission by ordering GKAP-containing complexes in dendritic spines. Beyond illuminating the role of DLC2-GKAP interactions in glutamatergic signaling, these data underscore the power of the sN&B approach for quantitative spatio-temporal imaging of other important protein complexes.

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International audience

Nucleic acids symposium series 42(15), 10173 - 10184(2014). doi:10.1093/nar/gku692, In vertebrates, smooth muscle cells (SMCs) can reversibly switch between contractile and proliferative phenotypes. This involves various molecular mechanisms to reactivate developmental signaling pathways and induce cell dedifferentiation. The protein RBPMS2 regulates early development and plasticity of digestive SMCs by inhibiting the bone morphogenetic protein pathway through its interaction with NOGGIN mRNA. RBPMS2 contains only one RNA recognition motif (RRM) while this motif is often repeated in tandem or associated with other functional domains in RRM-containing proteins. Herein, we show using an extensive combination of structure/function analyses that RBPMS2 homodimerizes through a particular sequence motif (D-x-K-x-R-E-L-Y-L-L-F: residues 39–51) located in its RRM domain. We also show that this specific motif is conserved among its homologs and paralogs in vertebrates and in its insect and worm orthologs (CPO and MEC-8, respectively) suggesting a conserved molecular mechanism of action. Inhibition of the dimerization process through targeting a conserved leucine inside of this motif abolishes the capacity of RBPMS2 to interact with the translational elongation eEF2 protein, to upregulate NOGGIN mRNA in vivo and to drive SMC dedifferentiation. Our study demonstrates that RBPMS2 possesses an RRM domain harboring both RNA-binding and protein-binding properties and that the newly identified RRM-homodimerization motif is crucial for the function of RBPMS2 at the cell and tissue levels., Published by Oxford Univ. Press8619, Oxford

International audience; In 1994, a technique of omental flap interposition to cover the celiac and mesenteric vessels after pancreaticoduodenectomy was described. It aimed to isolate the pancreatic anastomosis from the vessels dissected during pancreaticoduodenectomy. In liver transplantation (LT), the omental flap was initially used to reduce the risk of hepatic artery (HA) kinking. Currently, we use this technique to cover the dissected HA, reducing the consequences of postoperative biliary fistula (BF), particularly the risk of postoperative complications (thrombosis/bleeding). We describe this technique adding a simple modification consisting of covering the HA with an omental flap after completion of the biliary anastomosis. We performed LT with an omental flap to cover the HA vessels in 62 (55 %) of the 112 consecutive patients who underwent LT between January 2012 and July 2013. No postoperative deaths occurred. The rate of BF was 9.7 % (six cases). In the omental flap series, no postoperative thrombosis, HA pseudoaneurysm, or complications occurred. In the six cases of BF, the dissected HAs were completely isolated from the biloma. This simple technique has no specific morbidity; it isolates the HA from the biliary anastomosis and therefore may reduce the risk of severe postoperative HA complications after LT.