Karen Lambert

Karen Lambert
Université de Montpellier | UM1 · Physiologie & médecine expérimentale du Cœur et des Muscles - INSERM - U1046

Ph.D. HDR

About

86
Publications
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Publications

Publications (86)
Article
Full-text available
Metabolic skeletal muscle (SM) dysfunction, triggered by increased oxidative stress and mitochondrial impairment, is a pivotal contributor to obesity-associated insulin resistance (IR). Addressing obesity and SM IR demands substantial lifestyle changes including regular exercise and dietary adjustments that are difficult to follow over time. This p...
Article
The relationship between functional shoulder deficits in children with neonatal brachial plexus palsy (NBPP) and magnetic resonance imaging (MRI) shoulder abnormalities was evaluated. Shoulder function was assessed in 16 children (mean age: 5.8 years; range: 3–12 years) with NBPP based on shoulder rotator muscle strength, as measured using an isoki...
Article
The increase in obesity has become a major global health problem and is associated with numerous metabolic dysfunctions. Furan fatty acids (FuFAs) are minor lipids present in our diet. Recently we showed that FuFA-F2 extracted from Hevea brasiliensis latex stimulates muscle anabolism in mice in vitro and in vivo, mimicking in part physical activity...
Article
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Metabolic syndrome (METS) is a complex disorder that predisposes an affected person to an increased risk of diabetes and cardiovascular disease. Bitter Asteraceae plants contain several compounds active against METS that can be used as an alternative preventive therapy. Our previous work showed that a natural chicory extract (NCRAE) containing chic...
Article
Full-text available
Purpose: The purpose of this study was to evaluate the effect of pre-exercise alkalosis, induced via ingestion of sodium bicarbonate, on changes to lactate/pH regulatory proteins and mitochondrial function induced by a sprint-interval exercise session in humans. Methods: On two occasions separated by 1 week, eight active men performed a 3 × 30-s al...
Article
Branched fatty acid esters of hydroxy fatty acids (FAHFAs) are endogenous lipids reported to have antidiabetic and anti-inflammatory effects. Recently, we showed that 9-PAHPA and 9-OAHPA increased insulin sensitivity in mice when incorporated to a chow diet or to a high fat and high sucrose diet (HFHS). However, preventive supplementation with 9-PA...
Article
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Today, inactivity and high-calorie diets contribute to the development of obesity and premature aging. In addition, the population of elderly people is growing due to improvements in healthcare management. Obesity and aging are together key risk factors for non-communicable diseases associated with several co-morbidities and increased mortality, wi...
Article
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Palm olein (PO) and lard are considered harmful to health because of their highly saturated fatty acid content. On the contrary, olive oil (OO) with its high level of polyunsaturated fatty acids is considered healthier. This study aims to evaluate the effects of high consumption of these oils on carbohydrate metabolism and vascular function. Male W...
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The screening of skeletal muscle diseases constitutes an unresolved challenge. Currently, exercise tests or plasmatic tests alone have shown limited performance in the screening of subjects with an increased risk of muscle oxidative metabolism impairment. Intensity-adjusted energy sub-strate levels of lactate (La), pyruvate (Pyr), β-hydroxybutyrate...
Article
PurposeQuantifying changes in shoulder external rotation range of motion and strength after lower trapezius transfer in children with obstetric brachial plexus palsy (OBPP).Methods This prospective study included five children with sequelae of OBPP, with a mean age of 6.4 years (range: 4–12 years) who underwent lower trapezius tendon transfer to re...
Article
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Palm olein (PO) and olive oil (OO) are widely consumed in the world. PO is considered harmful to health, whereas OO is considered healthy. The aim of the study was to compare the effects of consumption of these oils on antioxidant status and inflammation in rats. This was an experimental study in male wistar rats fed a diet containing 30% of each o...
Article
The transient receptor potential Melastatin 4 (TRPM4) channel is a calcium-activated non-selective cation channel expressed widely. In the heart, using a knock-out mouse model, the TRPM4 channel has been shown to be involved in multiple processes, including β-adrenergic regulation, cardiac conduction, action potential duration and hypertrophic adap...
Article
Obesity and exercise lead to structural changes in heart such as cardiac hypertrophy. The underlying signaling pathways vary according to the source of the overload, be it physiological (exercise) or pathologic (obesity). The physiological pathway relies more on PI3K-Akt signaling while the pathologic pathway involves calcineurin-Nuclear factor of...
Article
The prevalence of metabolic syndrome (MetS), elevating cardiovascular risks, is increasing worldwide, with no available global therapeutic options. The intake of plain, mineral or biocompatible modified waters was shown to prevent some MetS features. This study was designed to analyze, in mice fed a high fat and sucrose diet (HFSD), the effects on...
Article
Introduction et but de l’étude Individuellement, la supplémentation en polyphénols de raisin et l’exercice ont démontré des effets bénéfiques sur la prise en charge de l’obésité et les atteintes du métabolisme cardiaque. Le but de cette étude était d’évaluer l’impact de l’association de l’exercice et d’une supplémentation en polyphénols de raisin à...
Article
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Purpose Palm (PO) and olive oils (OO) are the two most consumed and/or used oils in the world for food elaboration. These oils should not be confused with the solid palm stearin which is widely used in pastry making. Large number of studies was reported dealing with adverse/beneficial cardiovascular effects of PO and OO, whereas few studies were co...
Article
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One of the major insulin resistance instigators is excessive adiposity and visceral fat depots. Individually, exercise training and polyphenol intake are known to exert health benefits as improving insulin sensitivity. However, their combined curative effects on established obesity and insulin resistance need further investigation particularly on w...
Article
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Separately, polyphenols and exercise are known to prevent insulin resistance (IR) but their combined curative effects on established obesity and IR require further investigation. Therefore, we compared the metabolic effects of a combination of exercise and grape polyphenols supplementation in obese IR rats with high-fat diet (EXOPP) to the effect o...
Article
Context: Toll-like receptor 4 (TLR4) activation contributes to obesity-associated insulin resistance in skeletal muscles (SM). TLR4 signaling involves two pathways: the myeloid differentiation primary response gene 88 (MyD88) leading to inflammatory cytokines production and the toll/interleukin-1 receptor domain-containing adapter-inducing interfe...
Article
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Laccase enzymes produced by Botrytis cinerea are involved in the oxidation of phenolic substances during the development of grey mould, which causes significant economic losses. The aim of this work was to study the structural and activity characteristics of the laccase enzymes secreted by three B. cinerea strains that are involved in the developme...
Article
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Cardiac hypertrophy (CH) is an adaptive process that exists in two distinct forms and allows the heart to adequately respond to an organism’s needs. The first form of CH is physiological, adaptive and reversible. The second is pathological, irreversible and associated with fibrosis and cardiomyocyte death. CH involves multiple molecular mechanisms...
Article
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Introduction et but de l’étude La résistance à l’insuline est liée à une inflexibilité métabolique. Celle-ci se traduit par une mauvaise prise en charge des lipides et de leurs oxydations induisant leurs accumulations dans les tissus et particulièrement dans le muscle [1]. Ce défaut d’utilisation des lipides au cours de l’exercice a récemment été a...
Article
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Context: Obesity is associated with insulin-resistance (IR), the key feature of type 2 diabetes. Although chronic low-grade inflammation has been identified as a central effector of IR development, it has never been investigated simultaneously at systemic level and locally in skeletal muscle and adipose tissue in obese humans characterized for the...
Data
Macrophage staining in SAT and skeletal muscle. Representative immunohistochemical staining of pro-inflammatory macrophages (M1, CD86: red; total, CD68: green) and anti-inflammatory macrophages (M2, CD206: red; total, CD68: green) in SAT (Panel A) and skeletal muscle (Panel B). Nuclei were stained with DAPI in blue. On each image the arrow indicate...
Article
The prevalence of the metabolic syndrome components including abdominal obesity, dyslipidaemia and insulin resistance is increasing in both developed and developing countries. It is generally accepted that the development of these features is preceded by, or accompanied with, impaired mitochondrial function. The present study was designed to analys...
Article
Full-text available
The purpose of this study was to investigate the effect of subacute exposure to static magnetic fields (SMF) on hematological and muscle biochemical parameters in rats. Male Wistar rats, daily exposed to SMF, were exposed to SMF (128 mT, 1 h/day) during 15 consecutive days. SMF-exposed rats showed a significant decrease in red blood cell (RBC) coun...
Article
Polyphenols (PP) have demonstrated beneficial effects on low-grade inflammation and oxidative stress; however, little is known about their effect on highly inflamed muscle. The purposes of this study were (i) to evaluate muscle alteration induced by high-grade inflammation, and (ii) to test the effects of red grape PP supplementation on these alter...
Article
Introduction L’obésité a un retentissement important sur la santé en favorisant la survenue de pathologies chroniques, dont l’insulinorésistance (IR) et le diabète de type 2. Toutes les personnes obèses ne présentent cependant pas de complication métabolique et 20–25% d’entre elles sont « métaboliquement saines » (IS) avec un niveau de sensibilité...
Article
Full-text available
OBJECTIVE To assess the clinical efficacy of nutritional amounts of grape polyphenols (PPs) in counteracting the metabolic alterations of high-fructose diet, including oxidative stress and insulin resistance (IR), in healthy volunteers with high metabolic risk.RESEARCH DESIGN AND METHODS Thirty-eight healthy overweight/obese first-degree relatives...
Article
The World Health Organization (WHO) reports a global doubling in obesity cases between 1980 and 2011. The reasons for this are numerous but remain incompletely understood. The evolution of our lifestyles, especially our eating habits with the overconsumption of fatty and sugary foods, coupled with a drastic decrease in energy expenditure undoubtedl...
Article
Facioscapulohumeral muscular dystrophy (FSHD), the most frequent muscular dystrophy, is an autosomal dominant disease. In most individuals with FSHD, symptoms are restricted to muscles of the face, arms, legs, and trunk. FSHD is genetically linked to contractions of the D4Z4 repeat array causing activation of several genes. One of these maps in the...
Article
Overfeeding, an increased intake of saturated fatty acids, and sugary foods are key dietary changes that have occurred in recent decades in addition to the emergence of the obesity epidemic. In addition to an increase in energy storage as fat, these dietary changes are accompanied by an increase in mitochondrial macronutrient oxidation, leading to...
Article
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Adipose tissue structure is altered during obesity, leading to deregulation of whole-body metabolism. Its function depends on its structure, in particular adipocytes number and differentiation stage. To better understand the mechanisms regulating adipogenesis, we have investigated the role of an endoribonuclease, endoribonuclease L (RNase L), using...
Article
Nous avons préalablement montré que les polyphénols de raisin rouge (PP) protégeaient des effets délétères du fructose sur le métabolisme glucidique (SFD 2011). Nous évaluons ici les mécanismes de ces effets protecteurs.Patients et méthodes38 sujets en surpoids apparentés au 1er degré à des DT2 ont été randomisés en double aveugle entre un groupe P...
Article
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Two lactate/proton cotransporter isoforms (monocarboxylate transporters, MCT1 and MCT4) are present in the plasma (sarcolemmal) membranes of skeletal muscle. Both isoforms are symports and are involved in both muscle pH and lactate regulation. Accordingly, sarcolemmal MCT isoform expression may play an important role in exercise performance. Acute...
Article
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The aim of this study was to investigate if the metabolic alterations observed after static magnetic field (SMF) exposure participates in the development of a pre-diabetic state. A comparison study using the insulin resistant animal model, the Zucker rat and the SMF-exposed Wistar rat was carried out. Zucker rats were compared to Wistar rats either...
Article
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Maternal obesity and post-natal over-nutrition play an important role in programming glucose and lipid metabolism later in life. The aim of this study was to decipher the contributions of maternal obesity and post-natal over-nutrition on glucose and lipid metabolism in skeletal muscle. Male offspring of Sprague Dawley rat mothers fed either chow or...
Article
Recent evidence suggests that oxidative stress is a cornerstone of the metabolic mechanisms by which overfeeding leads to insulin resistance. This review is an update of the most recent arguments in favor of this theory and of the possible role of antioxidants. Reactive oxidative species (ROS) are produced by multiple pathways within the cell and a...
Article
Increasing environmental pollution may participate in the growing incidence of metabolic disorders. Static magnetic fields (SMFs) are an emerging environmental health issue due to increased exposure in residential and commercial areas; however, their metabolic effects in serum and skeletal muscle are largely unknown. The aim of this study was to in...
Article
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Intramyocellular lipids (IMCL) accumulation is a classical feature of metabolic diseases. We hypothesised that IMCL accumulate mainly as a consequence of increased adiposity and independently of type 2 diabetes. To test this, we examined IMCL accumulation in two different models and four different populations of participants: muscle biopsies and pr...
Article
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Maternal obesity is increasing, and it is known that the intrauterine experience programs fetal and newborn metabolism. However, the relative contributions of pre- or postnatal factors are unknown. We hypothesized that maternal overnutrition caused by long-term maternal obesity would exert a stronger detrimental impact than postnatal overnutrition...
Article
Abstract The purpose of this study was to investigate the effect of subacute exposure to static magnetic fields (SMF) on hematological and muscle biochemical parameters in rats. Male Wistar rats, daily exposed to SMF, were exposed to SMF (128 mT, 1 h/day) during 15 consecutive days. SMF-exposed rats showed a significant decrease in red blood cell (...
Article
Aim: We investigated whether or not, in type 2 diabetic (T2D) patients, an individualized training effect on whole-body lipid oxidation would be associated with changes in muscle oxidative capacity. Methods: Eleven T2D patients participated in the study. Whole-body lipid oxidation during exercise was assessed by indirect calorimetry during grade...
Article
The aim of this study was to determine the influence of angiotensin-converting enzyme (ACE) genotype on left ventricular growth after endurance training, in ACE congenic rats with plasma ACE activity twice as high as the donor strain (LOU), thus mimicking the ACE I/D polymorphism observed in humans. LOU and congenic rats (n = 12) were submitted to...
Article
Ability to use different substrate pathways (oxidative glycolysis, β-oxidation) reflects body functionality and its metabolic flexibility i.e. capacity to shift between lipids or carbohydrates utilization, at rest or during exercise. Metabolic function changes between childhood to oldness. Women are a specific population because of their hormonal v...
Article
This study aimed to provide detailed data on mitochondrial respiration of normal astrocyte cell lines derived from rat embryonic spinal cord. Astrocytes in early passages (EP), cultured without pyruvate for more than 35 passages, defined here as late passages (LP), undergo spontaneous transformation. To study initial steps in cell transformation, E...
Article
The purpose of this study was to investigate the effect of endurance training (10 weeks) on previously reported alterations of lactate exchange in obese Zucker fa/fa rats. We used sarcolemmal vesicles to measure lactate transport capacity in control sedentary rats, Zucker (fa/fa), and endurance trained Zucker (fa/fa) rats. Monocarboxylate transport...
Article
To dissect the independent effects of altitude-induced hypoxemia and anorexia on the capacity for cardiac lactate metabolism, we examined the effects of 21 days of chronic hypobaric hypoxia (CHH) and its associated decrease in food intake and right ventricle (RV) hypertrophy on the monocarboxylate transporter 1 and 4 (MCT) expression, the rate of l...
Article
There is no consensus regarding the most appropriate management of asymptomatic cholelithiasis in patients awaiting renal transplantation. Cholecystectomy is considered before renal transplantation because of potential worsened complications from cholelithiasis with posttransplantation immunosuppression. This study reviewed the outcomes for operati...
Article
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The present study investigated whether muscular monocarboxylate transporter (MCT) 1 and 4 contents are related to the blood lactate removal after supramaximal exercise, fatigue indexes measured during different supramaximal exercises, and muscle oxidative parameters in 15 humans with different training status. Lactate recovery curves were obtained...
Article
This study investigated whether acute hyperoxia improves electrical muscle activity in active chronic obstructive pulmonary disease (COPD) patients with mild hypoxemia (rest PaO(2) = 9.1 +/- 0.4 kPa). Two identical incremental exercise tests were performed by nine patients while breathing either air or 30% oxygen. Pulmonary gas exchanges, venous co...
Article
The effect of endurance training on muscle electrical activity during general exercise testing was investigated in physically active patients with chronic obstructive pulmonary disease (COPD). Before and after rehabilitation, patients performed identical incremental exercise tests. Pulmonary gas exchange, venous lactate and pyruvate concentrations,...
Article
Full-text available
A diet high in sucrose or fructose progressively impairs glucose and lipid metabolism, which leads to insulin resistance. As mitochondria are the sites of the oxidation and utilization of these substrates, we hypothesized that a high sucrose diet would alter mitochondrial respiration. Male Wistar rats were fed high-sucrose (SU) or control (CTL) die...
Article
The objective of this study was to investigate the effects of 6 weeks of food restriction (FR) on sarcolemmal lactate transport in rats. The daily food consumption of rats was monitored for 10 days, after which they were assigned to either a control group (CTL, n = 7) that consumed food ad libitum or an FR group (n = 7) that received a daily ration...
Article
Diabetes is known to alter both oxidative and glycolytic pathways in a fiber type-dependent manner. In various skeletal muscles of normal rats, monocarboxylate transporter 1 (MCT1) has been found to be highly correlated to lactate uptake, as well as to oxidative capacity, whereas the distribution and characteristics of MCT4 make it a good candidate...
Article
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Previous studies have shown that undernutrition induces an impairment of the respiratory muscle function in patients with chronic lung disease. To explain this, we hypothesized that undernutrition could decrease oxidative metabolism in the diaphragm. We therefore examined the effect of prolonged undernutrition on diaphragm mitochondrial oxygen upta...
Article
Temporary catheters are still essential for acute dialysis access but their performance has not been compared in randomized trials. We conducted a randomized trial of our standard catheter and a newly designed catheter. The primary outcome was maximized blood flow over the entire use of the catheter. Seventy-six patients provided maximum blood flow...
Article
Full-text available
The present experiments were undertaken to characterize 1) the hindlimb muscle mass lactate uptake and 2) the expression of monocarboxylate transporter isoforms MCT1 and MCT4, as well as lactate dehydrogenase (LDH) isozyme distribution, in various skeletal muscles of Zucker fa/fa rats taken as a model of insulin resistance-related obesity. Initial...
Article
Osteoporosis is a well-documented complication of organ transplantation. Bisphosphonates have been shown to be effective in preventing corticosteroid-induced osteoporosis in renal transplant recipients, but data are lacking for treatment of established osteoporosis. This study reports our clinical experience of treatment with the bisphosphonate eti...
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The effects of endurance training on lactate transport capacity remain controversial. This study examined whether endurance training 1) alters lactate transport capacity, 2) can protect against exhaustive exercise-induced lactate transport alteration, and 3) can modify heart and oxidative muscle monocarboxylate transporter 1 (MCT1) content. Forty m...
Article
The pharmacokinetics of cyclophosphamide (CY) and 4-hydroxycyclophosphamide (HCY) were studied in 14 patients being prepared for bone marrow transplantation with either busulfan (BU)/CY (n = 7) or CY/total-body irradiation (TBI) (n = 7) to determine whether exposure to CY and its proximate toxic metabolite HCY is modulated by other agents used in t...
Article
In a previous phase I study, it was concluded that tolerable doses of busulfan (BU), cyclophosphamide (CY) and total body irradiation (TBI) were 8 mg/kg, 60 mg/kg and 12.0 Gy, respectively, for autologous marrow transplant recipients. In an attempt to decrease the variability of BU steady-state concentration (Css) following oral dosing, a BU dose e...