The role of CD36-Fabp4-PPARγ in skeletal muscle involves insulin resistance in intrauterine growth retardation mice with catch-up growth

Background Studies have shown that the high incidence of type 2 diabetes in China is associated with low birth weight and excessive nutrition in adulthood, which occurred during the famine years of the 1950s and 1960s, though the specific molecular mechanisms are unclear. In this study, we proposed a severe maternal caloric restriction during late pregnancy, followed by a post weaning high-fat diet in mice. After weaning, normal and high-fat diets were provided to mice to simulate the dietary pattern of modern society. Methods The pregnant mice were divided into two groups: normal birth weight (NBW) group and low birth weight (LBW) group. After 3 weeks for weaning, the male offspring mice in the NBW and LBW groups were then randomly divided into four subgroups: NC, NH, LC and LC groups. The offspring mice in the NC, NH, LC and LC groups were respectively fed with normal diet, normal diet, high-fat diet and high-fat diet for 18 weeks. After 18 weeks of dietary intervention, detailed analyses of mRNA and protein expression patterns, signaling pathway activities, and promoter methylation states were conducted for all relevant genes. Results After dietary intervention for 18 weeks, the expressions of CD36, Fabp4, PPARγ, FAS, and ACC1 in the skeletal muscle tissue of the LH group were significantly increased compared with the LC and NH groups (P < 0.05). The level of p-AMPK/AMPK in the skeletal muscle tissue of the LH group was significantly decreased compared with the LC and NH groups (P < 0.05). CPT1 and PGC-1α protein expressions were up-regulated in the LH group (P < 0.05) compared to the LC group. Additionally, the DNA methylation levels of the PGC-1α and GLUT4 gene promoters in the skeletal muscle of the LH groups were higher than those of the LC and NH groups (P < 0.05). However, PPARγ DNA methylation level in the LH group was lower than those of the LC and NH groups (P < 0.05). Conclusions LBW combined with high-fat diets may increase insulin resistance and diabetes through regulating the CD36-related Fabp4-PPARγ and AMPK/ACC signaling pathways.

Neuronal mechanisms of ginseng on antiobesity effects: implication of its synergistic benefits with physical exercise

Obesity is a chronic disease of increasing prevalence in most countries, which leads to substantial increase in morbidity, and mortality in association with diabetes, hyperlipidaemia, hypertension, and other cardiovascular diseases. Many factors have been attributed to an epidemic of obesity including sedentary lifestyle, high-fat diets (HFD), and consumption of large amount of modern fast foods. Panax ginseng C. A. Meyer (PG) has several pharmacological and physiological effects. In particular, PG and saponin fractions from PG show a variety of efficacies such as antifatigue, hyperlipidemia, hypertension and noninsulin-dependent diabetes mellitus and obesity. We have revealed that ginseng and ginsenosides can decrease food intake energy expenditure by stimulating appetite regulatory hormones and can reduce energy intake. Exercise/physical activity is well known as modality for treating the disease of overweight and obesity. It is suggested that natural products and their combinations with exercise may produce a synergistic activity that increases their bioavailability and action on multiple molecular targets, offering advantages over chemical treatments. This review is aimed at evaluating the antiobesity efficacy of ginseng and ginsenosides and delineating the mechanisms by which they function. Finally, we review information regarding interactions between ginseng and physical exercise in protecting against weight gain and obesity.

Curcumin exerts a protective effect against obesity and liver injury induced by an atherogenic diet

Background: Curcumin (Cur) is a natural yellow polyphenol extracted from the turmeric rhizome (Curcuma longa). Cur is known for its potential therapeutic properties as an analgesic, anti-inflammatory, antioxidant, antimicrobial, hepatoprotective, and anti-mutagenic, although some of these biological activities remain unproven. Epidemiological studies have shown a positive relationship between high-fat diets and diet-related chronic diseases. We hypothesized that some adverse effects of consuming atherogenic or high-fat diets (AD) can be ameliorated by Cur supplementation. Using an experimental model of rats, this study investigated the significance of Cur when it is given as a supplement in an AD.Methods: Healthy adult Wistar rats were randomly assigned to one of three groups. Controls (C) received a standard diet and experimental rats were fed with AD or AD+Cur for 5 weeks. Cur (100 mg/kg body weight) was given orally daily, plus piperine (5 mg/kg body weight). The effect of Cur supplementation was studied on zoometrics, visceral fat content, serum lipids profile, hepatosteatosis, liver function and oxidative status. Results: Diets did not alter energy consumption. As compared to the other groups, AD+Cur group showed a lower total visceral fat content, percentage of perirenal, mesenteric, and pelvic fat, and body weight gain (P< 0.05). Serum total cholesterol (P<0.0001), non-HDL-C (P<0.0001) levels were significantly higher in AD groups as compared with C. Serum triglycerides and HDL-C levels remained similar among groups (P>0.05). AD induced a liver injury with macrovesicular steatosis and portal inflammation. AD+Cur rats presented microvesicular steatosis with no inflammation, achieving the lowest level of alanine aminotransferase (ALT; P<0.0001) and reductions of aspartate aminotransferase (AST; P<0.0001). Liver homogenates from AD+Cur showed that Cur supplementation reduced the dichlorofluorescein diacetate (DCFH-DA) oxidation rate induced by AD by 25 % and deferoxamine and superoxide dismutase inhibited DCFH-DA. Conclusion: Cur as a dietary supplement showed a protective effect against obesity and inflammation, but its cardioprotective ability remained unproved. Cur may develop as a promising therapeutic agent for liver diseases induced by oxidative stress. This study provides supporting evidence to confirm the beneficial effects of curcumin from the point of view of functional food science. Keywords: curcumin, liver injury, ROS, atherogenic diet, visceral fat, obesity

Ketogenic Diet for Obese COVID-19 Patients: Is Respiratory Disease a Contraindication? A Narrative Review of the Literature on Ketogenic Diet and Respiratory Function

Morbid obese people are more likely to contract SARS-CoV-2 infection and its most severe complications, as need for mechanical ventilation. Ketogenic Diet (KD) is able to induce a fast weight loss preserving lean mass and is particularly interesting as a preventive measure in obese patients. Moreover, KD has anti-inflammatory and immune-modulating properties, which may help in preventing the cytokine storm in infected patients. Respiratory failure is actually considered a contraindication for VLCKD, a very-low calorie form of KD, but in the literature there are some data reporting beneficial effects on respiratory parameters from ketogenic and low-carbohydrate high-fat diets. KD may be helpful in reducing ventilatory requirements in respiratory patients, so it should be considered in specifically addressed clinical trials as an adjuvant therapy for obese patients infected with SARS-CoV-2.

FXR, a Key Regulator of Lipid Metabolism, Is Inhibited by ER Stress-Mediated Activation of JNK and p38 MAPK in Large Yellow Croakers (Larimichthys crocea) Fed High Fat Diets

High-fat diets induced abnormal lipid accumulation in the liver of cultured fish that caused body damage and diseases. The purpose of this research was to investigate the role and mechanism of farnesoid X receptor (FXR) in regulating lipid metabolism and to determine how high-fat diets affect FXR expression in large yellow croakers. The results showed that ligand-meditated FXR-activation could prevent abnormal lipid accumulation in the liver and hepatocytes of large yellow croakers. FXR activation increased the expression of lipid catabolism-related genes while decreasing the expression of lipogenesis-related genes. Further investigation found that the promoter activity of proliferator-activated receptor α (PPARα) could be increased by croaker FXR. Through the influence of SHP on LXR, FXR indirectly decreased the promoter activity of sterol regulatory element binding protein 1 (SREBP1) in large yellow croakers. Furthermore, the findings revealed that endoplasmic reticulum (ER)-stress-induced-activation of JNK and P38 MAPK participated in the reduction of FXR induced by high-fat diets. Then, hepatocyte nuclear factor 1α (HNF1α) was confirmed to be an FXR regulator in large yellow croaker, and it was reduced by high-fat diets and ER stress. In addition, co-expression of c-Jun with HNF1α inhibited the effect of HNF1α on FXR promoter, and suppression of P38 MAPK could relieve the HNF1α expression reduction caused by ER stress activation. In summary, the present study showed that FXR mediated lipid metabolism can prevent abnormal lipid accumulation through regulating PPARα and SREBP1 in large yellow croakers, while high-fat diets can suppress FXR expression by ER stress mediated-activation of JNK and P38 MAPK pathways. This research could benefit the study of FXR functions in vertebrate evolution and the development of therapy or preventative methods for nutrition-related disorders.

Methionine Metabolism in Aging Regulation

Aging is the major risk factor for many diseases but the mechanisms are poorly understood. The risk of developing hepatic steatosis increases with age and the health impact of this disease is negative and high. When challenged with high fat diets, long living Ames mice withstand the detrimental metabolic effects that occur in normal mice. We examined transcriptomic and epigenomic profiles of Ames and wild type hepatocytes in the presence or absence of fat to demonstrate that the epigenomic profile drives transcription factor and downstream gene expression resulting in susceptibility or resistance to fatty liver disease. We found that markers of steatosis are related to gene expression in wild type and Ames mice, and dwarf mice retain fewer lipid droplets compared to wild type mice. These studies will provide data to guide our understanding of mechanisms leading to hepatic disease and define factors that provide protection from age-related metabolic disorders.