Polyunsaturated fatty acids prevent myosteatosis and lipotoxicity.

Myosteatosis occurs in response to excess circulating fatty acids and is associated with muscle dysfunction. This study aimed to characterize the sequence of events of lipid-induced toxicity within muscle cells and the role of polyunsaturated fatty acids (PUFA) as potential preventive factors. Myosteatosis was induced in C2C12 myotubes exposed to palmitic acid (PAL 500µM).

An experimental model of western diet in female Wistar rats leads to cardiac hypoxia related to a stimulated contractility.

Previous studies in Western diet (WD)-fed male rats have highlighted a link between the stimulation of cardiac contractility, mitochondrial adaptations and a pro-inflammatory fatty acid profile of phospholipids in the heart. Our objectives were to determine (1) if WD-fed female Wistar rats and obese humans display a similar pro-inflammatory profile in their cardiac phospholipids and (2) if this lipid profile is associated with deleterious effects on the heart of the female rodents. Female Wistar rats were fed WD for 5 weeks or a laboratory chow as a control.

Docosahexaenoic acid and etanercept could reduce functional and metabolic alterations during collagen-induced arthritis in rats without any synergistic effect.

Aims: Rheumatoid arthritis is an autoimmune disease which induces chronic inflammation and increases the risk for sarcopenia and metabolic abnormalities. Nutritional strategies using omega 3 polyunsaturated fatty acids could be proposed to alleviate inflammation and improve the maintenance of lean mass. Independently, pharmacological agents targeting key molecular regulators of the pathology such as TNF alpha could be proposed, but multiple therapies are frequently necessary increasing the risk for toxicity and adverse effects.

Eccentric and concentric exercises induce different adaptions in adipose tissue biology.

Alterations in adipose tissue (AT) metabolism related to inflammation and adipokine's production lead to perturbations in its capacity to store lipids and release fatty acids (FA) during feeding/fasting transition or during exercise. Exercise has a beneficial effect on AT metabolism, but conventional trainings are not always suitable for patients with functional limitations. Dynamic eccentric (ECC) exercise prevents the accumulation of AT and may then overcome those limitations.

Inhibition of the endocannabinoid system reverses obese phenotype in aged mice and partly restores skeletal muscle function.

Sarcopenia, the age-related loss of skeletal muscle mass, is associated with lipid accumulation and anabolic resistance; phenomena also observed in obesity and worsen when obesity and aging are combined. The endocannabinoid system (ECS) is overactivated in obesity, but its role in aging obesity-related muscle dysfunction is unknown. The aims of this study were to evaluate the effect of inhibition of the ECS by rimonabant (RIM) on the metabolic alterations induced by a high-fat high-sucrose diet and on skeletal muscle mass/function in aged mice.

Deleterious Effect of High-Fat Diet on Skeletal Muscle Performance Is Prevented by High-Protein Intake in Adult Rats but Not in Old Rats.

The phenotype of sarcopenic obesity is frequently associated with impaired muscle strength and performance. Ectopic lipid deposition may interfere with muscle anabolic response especially during aging. Evidence is scarce concerning the potential interplay among aging and nutrient imbalance on skeletal muscle functionality.

Adipose Tissue Dysfunctions in Response to an Obesogenic Diet Are Reduced in Mice after Transgenerational Supplementation with Omega 3 Fatty Acids.

Obesity is characterized by profound alterations in adipose tissue (AT) biology, leading to whole body metabolic disturbances such as insulin resistance and cardiovascular diseases. These alterations are related to the development of a local inflammation, fibrosis, hypertrophy of adipocytes, and dysregulation in energy homeostasis, notably in visceral adipose tissue (VAT). Omega 3 (n-3) fatty acids (FA) have been described to possess beneficial effects against obesity-related disorders, including in the AT; however, the long-term effect across generations remains unknown.

The effect of camelina oil on vascular function in essential hypertensive patients with metabolic syndrome: a randomized, placebo-controlled, double-blind study.

Background: The effects of a dietary supplementation with the vegetable ω-3 α-linolenic acid (ALA) on cardiovascular homeostasis are unclear. In this context, it would be interesting to assess the effects of camelina oil.

Objective: This study aimed to assess the cardiovascular and metabolic effects of camelina oil in hypertensive patients with metabolic syndrome.

A chronic low-dose magnesium L-lactate administration has a beneficial effect on the myocardium and the skeletal muscles.

The purpose of this study was to determine whether magnesium L-lactate is responsible for having a beneficial effect on the myocardium and the skeletal muscles and how this substrate acts at the molecular level. Twenty seven young male Wistar rats were supplied with a magnesium L-lactate (L) solution, a magnesium chloride (M) solution and/or water (W) as a vehicle for 10 weeks. The treated animals absorbed the L and M solutions as they wished since they also had free access to water.

Transgenerational supplementation with eicosapentaenoic acid reduced the metabolic consequences on the whole body and skeletal muscle in mice receiving an obesogenic diet.

Purpose: The effect of manipulating the fatty acid profile of the diet over generations could affect the susceptibility to develop obesity and metabolic disorders. Although some acute effects were described, the impact of transgenerational continuous supplementation with omega 3 fatty acids on metabolic homeostasis and skeletal muscle metabolic flexibility during a nutritional stress is unknown.

Methods: We analyzed the effect of an obesogenic diet in mice after transgenerational supplementation with an omega-3 rich oil (mainly EPA) or a control oil.

An Integrated Analysis of miRNA and Gene Expression Changes in Response to an Obesogenic Diet to Explore the Impact of Transgenerational Supplementation with Omega 3 Fatty Acids.

Insulin resistance decreases the ability of insulin to inhibit hepatic gluconeogenesis, a key step in the development of metabolic syndrome. Metabolic alterations, fat accumulation, and fibrosis in the liver are closely related and contribute to the progression of comorbidities, such as hypertension, type 2 diabetes, or cancer. Omega 3 (-3) polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA), were identified as potent positive regulators of insulin sensitivity in vitro and in animal models.

EPA is Cardioprotective in Male Rats Subjected to Sepsis, but ALA Is Not Beneficial.

It has been proven that dietary eicosapentaenoic acid (C20:5 n-3 or EPA) protects the heart against the deleterious effects of sepsis in female rats. We do not know if this is the case for male rodents. In this case, the efficiency of other n-3 polyunsaturated fatty acids (PUFAs) remains to be determined in both female and male rats.

Antioxidant and Cardioprotective Effects of EPA on Early Low-Severity Sepsis through UCP3 and SIRT3 Upholding of the Mitochondrial Redox Potential.

Sepsis still causes death, often through cardiac failure and mitochondrial dysfunction. Dietary 3 polyunsaturated fatty acids are known to protect against cardiac dysfunction and sepsis lethality. This study set out to determine whether early low-severity sepsis alters the cardiac mitochondrial function in animals fed a Western-type diet and whether dietary eicosapentaenoic acid (EPA) administration protects the myocardium against the deleterious effects of sepsis and if so to seek possible mechanisms for its effects.

Metabolomics reveals plausible interactive effects between dairy product consumption and metabolic syndrome in humans.

Background & Aims: Metabolic syndrome (MetS) induces major disturbances in plasma metabolome, reflecting abnormalities of several metabolic pathways. Recent evidences have demonstrated that the consumption of dairy products may protect from MetS, but the mechanisms remains unknown. The present study aimed at identify how the consumption of different types of dairy products could modify the changes in plasma metabolome during MetS.

Impact of Eccentric or Concentric Training on Body Composition and Energy Expenditure.

Purpose: To compare the effects of 8-wk eccentric (ECC) versus concentric (CON) training using downhill and uphill running in rats on whole body composition, bone mineral density (BMD), and energy expenditure.

Methods: Animals were randomly assigned to one of the following groups: 1) control (CTRL), 2) +15% uphill-running slope (CON), 3) -15% downhill-running slope (ECC15), and 4) -30% downhill-running slope (ECC30). Those programs enabled to achieve conditions of isopower output for CON and ECC15 and of iso-oxygen uptake (V˙O2) for CON and ECC30.

Modulation of Insulin Resistance and the Adipocyte-Skeletal Muscle Cell Cross-Talk by LCn-3PUFA.

The cross-talk between skeletal muscle and adipose tissue is involved in the development of insulin resistance (IR) in skeletal muscle, leading to the decrease in the anabolic effect of insulin. We investigated if the long chain polyunsaturated n-3 fatty acids (LCn-3PUFA), eicosapentaenoic and docosapentaenoic acids (EPA and DPA, respectively) could (1) regulate the development of IR in 3T3-L1 adipocytes and C2C12 muscle cells and (2) inhibit IR in muscle cells exposed to conditioned media (CM) from insulin-resistant adipocytes. Chronic insulin (CI) treatment of adipocytes and palmitic acid (PAL) exposure of myotubes were used to induce IR in the presence, or not, of LCn-3PUFA.

Dietary canolol protects the heart against the deleterious effects induced by the association of rapeseed oil, vitamin E and coenzyme Q10 in the context of a high-fat diet.

Background: Obesity progressively leads to cardiac failure. Omega-3 polyunsaturated fatty acids (PUFA) have been shown to have cardio-protective effects in numerous pathological situations. It is not known whether rapeseed oil, which contains α-linolenic acid (ALA), has a similar protective effect.

Early sepsis does not stimulate reactive oxygen species production and does not reduce cardiac function despite an increased inflammation status.

If it is sustained for several days, sepsis can trigger severe abnormalities of cardiac function which leads to death in 50% of cases. This probably occurs through activation of toll-like receptor-9 by bacterial lipopolysaccharides and overproduction of proinflammatory cytokines such as TNF- and IL-1 In contrast, early sepsis is characterized by the development of tachycardia. This study aimed at determining the early changes in the cardiac function during sepsis and at finding the mechanism responsible for the observed changes.

EPA prevents fat mass expansion and metabolic disturbances in mice fed with a Western diet.

The impact of alpha linolenic acid (ALA), EPA, and DHA on obesity and metabolic complications was studied in mice fed a high-fat, high-sucrose (HF) diet. HF diets were supplemented with ALA, EPA, or DHA (1% w/w) and given to C57BL/6J mice for 16 weeks and to Ob/Ob mice for 6 weeks. In C57BL/6J mice, EPA reduced plasma cholesterol (-20%), limited fat mass accumulation (-23%) and adipose cell hypertrophy (-50%), and reduced plasma leptin concentration (-60%) compared with HF-fed mice.

N-3PUFA differentially modulate palmitate-induced lipotoxicity through alterations of its metabolism in C2C12 muscle cells.

Excessive energy intake leads to fat overload and the formation of lipotoxic compounds mainly derived from the saturated fatty acid palmitate (PAL), thus promoting insulin resistance (IR) in skeletal muscle. N-3 polyunsaturated fatty acids (n-3PUFA) may prevent lipotoxicity and IR. The purpose of this study was to examine the differential effects of n-3PUFA on fatty acid metabolism and insulin sensitivity in muscle cells.

Long-term abdominal adiposity activates several parameters of cardiac energy function.

Abdominal obesity increases the incidence of cardiac events but reduces mortality when one of these events occurs. The phenomenon called obesity paradox might be related to myocardial energetics. This study was aimed at determining whether long-term abdominal adiposity alters cardiac energy function.

Combining citrulline with atorvastatin preserves glucose homeostasis in a murine model of diet-induced obesity.

Background And Purpose: NO is a crucial regulator of energy and lipid metabolism, whose homeostasis is compromised during obesity. Combination of citrulline and atorvastatin potentiated NO production in vitro. Here we have assessed the effects of this combination in mice with diet-induced obesity (DIO).

DHA at nutritional doses restores insulin sensitivity in skeletal muscle by preventing lipotoxicity and inflammation.

Skeletal muscle plays a major role in the control of whole body glucose disposal in response to insulin stimulus. Excessive supply of fatty acids to this tissue triggers cellular and molecular disturbances leading to lipotoxicity, inflammation, mitochondrial dysfunctions, impaired insulin response and decreased glucose uptake. This study was conducted to analyze the preventive effect of docosahexaenoic acid (DHA), a long-chain polyunsaturated n-3 fatty acid, against insulin resistance, lipotoxicity and inflammation in skeletal muscle at doses compatible with nutritional supplementation.

Body adiposity dictates different mechanisms of increased coronary reactivity related to improved in vivo cardiac function.

Background: Saturated fatty acid-rich high fat (HF) diets trigger abdominal adiposity, insulin resistance, type 2 diabetes and cardiac dysfunction. This study was aimed at evaluating the effects of nascent obesity on the cardiac function of animals fed a high-fat diet and at analyzing the mechanisms by which these alterations occurred at the level of coronary reserve.

Materials And Methods: Rats were fed a control (C) or a HF diet containing high proportions of saturated fatty acids for 3 months.