High-fat High-sucrose Research Articles

Modulation of methotrexate-induced intestinal mucosal injury by dietary factors.

Methotrexate (MTX)-induced intestinal mucosal injury in animals has been studied to understand how MTX can cause gastrointestinal disorders, but the pathogenesis of gastrointestinal disorders is still uncertain. We have attempted to reveal how dietary factors influence intestinal toxicity due to MTX. Mice were fed normal chow (NC) or a high-fat high-sucrose diet (HFHSD) before oral administration of MTX. While MTX significantly decreased the survival rates of mice fed HFHSD, the intestinal epithelial injury was detected. MTX excretion in the feces of mice fed HFHSD was reduced. Change of diets between NC and HFHSD influences the survival. The survival rates of the mice fed a high-sucrose diet or control diet were higher than those fed HFHSD. Higher survival rates were observed in mice fed a high-fat high-sucrose diet modified (HFHSD-M) in which casein was replaced by soybean-derived proteins. The survival rates of mice treated with vancomycin were lower than those administered neomycin. Microbiome and metabolome analyses on feces suggest a similarity of the intestinal environments of mice fed NC and HFHSD-M. HFHSD may modify MTX-induced toxicity in intestinal epithelia on account of an altered MTX distribution as a result of change in the intestinal environment.

DNA Methylation Changes More Slowly Than Physiological States in Response to Weight Loss in Genetically Diverse Mouse Strains.

Responses to a high fat, high sucrose (HFHS) diet vary greatly among inbred strains of mice. We sought to examine the epigenetic (DNA methylation) changes underlying these differences as well as variation in weight loss when switched to a low-fat chow diet. We surveyed DNA methylation from livers of 45 inbred mouse strains fed a HFHS diet for 8 weeks using reduced-representation bisulfite sequencing (RRBS). We observed a total of 1,045,665 CpGs of which 83 candidate sites were significantly associated with HFHS diet. Many of these CpGs correlated strongly with gene expression or clinical traits such as body fat percentage and plasma glucose. Five inbred strains were then studied in the context of weight loss to test for evidence of epigenetic “memory.” The mice were first fed a HFHS diet for 6 weeks followed by a low-fat chow diet for 4 weeks. Four of the five strains returned to initial levels of body fat while one strain, A/J, retained almost 50% of the fat gained. A total of 36 of the HFHS diet responsive CpGs exhibited evidence of persistent epigenetic modifications following weight normalization, including CpGs near the genes Scd1 and Cdk1. Our study identifies DNA methylation changes in response to a HFHS diet challenge that revert more slowly than overall body fat percentage in weight loss and provides evidence for epigenetic mediated “memory.”

Rapid and Concomitant Gut Microbiota and Endocannabinoidome Response to Diet-Induced Obesity in Mice.

The intestinal microbiota and the expanded endocannabinoid (eCB) system, or endocannabinoidome (eCBome), have both been implicated in diet-induced obesity and dysmetabolism. These systems were recently suggested to interact during the development of obesity. We aimed at identifying the potential interactions between gut microbiota composition and the eCBome during the establishment of diet-induced obesity and metabolic complications. Male mice were fed a high-fat, high-sucrose (HFHS) diet for 56 days to assess jejunum, ileum, and cecum microbiomes by 16S rRNA gene metataxonomics as well as ileum and plasma eCBome by targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS). The HFHS diet induced early (3 days) and persistent glucose intolerance followed by weight gain and hyperinsulinemia. Concomitantly, it induced the elevation of the two eCBs, anandamide, in both ileum and plasma, and 2-arachidonoyl-glycerol, in plasma, as well as alterations in several other N-acylethanolamines and 2-acylglycerols. It also promoted segment-specific changes in the relative abundance of several genera in intestinal microbiota, some of which were observed as early as 3 days following HFHS diet. Weight-independent correlations were found between the relative abundances of, among others, Barnesiella, Eubacterium, Adlercreutzia, Parasutterella, Propionibacterium, Enterococcus, and Methylobacterium and the concentrations of anandamide and the anti-inflammatory eCBome mediator N-docosahexaenoyl-ethanolamine. This study highlights for the first time the existence of potential interactions between the eCBome, an endogenous system of multifunctional signaling lipids, and several intestinal genera during early and late HFHS-induced dysmetabolic events, with potential impact on the host capability of adapting to increased intake of fat and sucrose.IMPORTANCE The intestinal microbiota and the expanded endocannabinoid system, or endocannabinoidome, have both been implicated in diet-induced obesity and dysmetabolism. This study aims at identifying the potential interactions between these two fundamental systems-which form the gut microbiota-endocannabinoidome axis-and their involvement in the establishment of diet-induced obesity and related metabolic complications. We report here time- and segment-specific microbiome disturbances as well as modifications of intestinal and circulating endocannabinoidome mediators during high-fat, high-sucrose diet-induced glucose intolerance and subsequent obesity and hyperinsulinemia. This highlights the involvement of, and the interaction between, the gut microbiota and the endocannabinoidome during metabolic adaptation to high-fat and high-sucrose feeding. These results will help identifying actionable gut microbiome members and/or endocannabinoidome mediators to improve metabolic health.

Angiotensin-(1-7) induces beige fat thermogenesis through the Mas receptor

ObjectiveAngiotensin-(1-7) [Ang-(1-7)], a component of the renin angiotensin system, is a vasodilator that exerts its effects primarily through the Mas receptor. The discovery of the Mas receptor in white adipose tissue (WAT) suggests an additional role for this peptide. The aim of the present study was to assess whether Ang-(1-7) can induce the expression of thermogenic genes in white adipose tissue and increase mitochondrial respiration in adipocytes. Materials/methodsStromal Vascular fraction (SVF)-derived from mice adipose tissue was stimulated for one week with Ang-(1-7), then expression of beige markers and mitochondrial respiration were assessed. Mas+/+ and Mas−/− mice fed a control diet or a high fat-sucrose diet (HFSD) were exposed to a short or long term infusion of Ang-(1-7) and body weight, body fat, energy expenditure, cold resistance and expression of beige markers were assessed. Also, transgenic rats overexpressing Ang-(1-7) were fed with a control diet or a high fat-sucrose diet and the same parameters were assessed. Ang-(1-7) circulating levels from human subjects with different body mass index (BMI) or age were measured. ResultsIncubation of adipocytes derived from SVF with Ang-(1-7) increased the expression of beige markers. Infusion of Ang-(1-7) into lean and obese Mas+/+mice also induced the expression of Ucp1 and some beige markers, an effect not observed in Mas−/− mice. Mas−/− mice had increased body weight gain and decreased cold resistance, whereas rats overexpressing Ang-(1-7) showed the opposite effects. Overexpressing rats exposed to cold developed new thermogenic WAT in the anterior interscapular area. Finally, in human subjects the higher the BMI, low circulating concentration of Ang-(1-7) levels were detected. Similarly, the circulating levels of Ang-(1-7) peptide were reduced with age. ConclusionThese data indicate that Ang-(1-7) stimulates beige markers and thermogenesis via the Mas receptor, and this evidence suggests a potential therapeutic use to induce thermogenesis of WAT, particularly in obese subjects that have reduced circulating concentration of Ang-(1-7).

Metabolic benefits of gastric bypass surgery in the mouse: The role of fecal losses

ObjectiveRoux-en-Y gastric surgery (RYGB) promotes a rapid and sustained weight loss and amelioration of glucose control in obese patients. A high number of molecular hypotheses were previously tested using duodenal-jejunal bypass (DJB) performed in various genetic models of mice with knockouts for various hormones or receptors. The data were globally negative or inconsistent. Therefore, the mechanisms remained elusive. Intestinal gluconeogenesis is a gut function that has been suggested to contribute to the metabolic benefits of RYGB in obese patients. MethodsWe studied the effects of DJB on body weight and glucose control in obese mice fed a high fat-high sucrose diet. Wild type mice and mice with a genetic suppression of intestinal gluconeogenesis were studied in parallel using glucose- and insulin-tolerance tests. Fecal losses, including excretion of lipids, were studied from the feces recovered in metabolic cages. ResultsDJB induced a dramatic decrease in body weight and improvement in glucose control (glucose- and insulin-tolerance) in obese wild type mice fed a high calorie diet, for 25 days after the surgery. The DJB-induced decrease in food intake was transient and resumed to normal in 7–8 days, suggesting that decreased food intake could not account for the benefits. Total fecal losses were about 5 times and lipid losses 7 times higher in DJB-mice than in control (sham-operated and pair-fed) mice, and could account for the weight loss of mice. The results were comparable in mice with suppression of intestinal gluconeogenesis. There was no effect of DJB on food intake, body weight or fecal loss in lean mice fed a normal chow diet. ConclusionsDJB in obese mice fed a high calorie diet promotes dramatic fecal loss, which could account for the dramatic weight loss and metabolic benefits observed. This could dominate the effects of the mouse genotype/phenotype. Thus, fecal energy loss should be considered as an essential process contributing to the metabolic benefits of DJB in obese mice.

Natural evolvement of lung tumors induced by N-ethyl-N-nitrosourea (ENU) and the impact of a high sucrose-high fat diet on tumor evolvement assessed by tumor histology in inbred BALB/c and C57BL/6J mice.

The model of lung tumors transplacentally induced by N-ethyl-N-nitrosourea (ENU) in inbred BALB/c and C57BL/6J mice was used to investigate the impact of a high sucrose-high fat (HSHF) diet on lung tumorigenesis. The offspring was separated by gender and randomly divided into 2 subgroups in both ENU- and buffer-treated groups at the time of weaning. One subgroup was put on the standard diet and the other on the HSHF diet from weaning to the age of 24 weeks. The entire lungs went through a standard process of paraffin-embedded blocks. Every lung block was cut in serial sections but one in every five sections was saved to generate step sections that were stained by hematoxylin and eosin. The tumor histology was assessed on the step sections. At 24-week checkpoint, a spectrum of histological changes was observed in the mice on both diets. Specifically, they presented as alveolar hyperplasia, adenomas and adenomas with nuclear dysplasia at various degrees. Those tumors were actually at different developmental stages. Lung adenocarcinomas were developed in mice on the HSHF diet. A cluster of tumor cells with wide foamy or clear or signet-ring shaped cytoplasm (fatty changes) appeared in a low frequency on the HSHF diet. The observed histological changes indicated that lung tumors were developed at different times and evolved at different paces. The HSHF diet accelerated the course of tumor evolvement. Tumor cells with fatty changes might be induced by the HSHF diet.

Codonopsis lanceolata polysaccharide CLPS alleviates high fat/high sucrose diet-induced insulin resistance via anti-oxidative stress

Polysaccharide has been considered as an important bioactive compound in Codonopsis lanceolata. High fat/high sucrose (HFHS) diet-induced insulin resistance is implicated in multiple metabolic diseases, such as type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD), these metabolic diseases has become epidemic health issue worldwide. In this study, the effect of C. lanceolata polysaccharide (CLPS) on improving insulin sensitivity in chronic HFHS diet-fed mice was investigated. Our data indicates that CLPS significantly reduced fasting blood glucose (FBG), fasting serum insulin (FINS) and insulin resistance index, in parallel with improved glucose and insulin tolerance impaired by HFHS diet. Impaired phosphorylation of PKB/Akt and hyperphosphorylation of IRS-1 at Ser307 were observed in the mice fed with HFHS diet, and those defects were also rescued by CLPS administration. In addition, CLPS caused a significant decrease in the level of malondialdehyde (MDA), and an increase in reduced glutathione (GSH)/oxidised glutathione (GSSG) ratio; concurrent with enhanced expression of antioxidant enzymes including superoxide dismutase (SOD) and catalase (CAT), and activated Nrf2 signaling. In summary, these findings suggest that CLPS ameliorates HFHS diet-induced insulin resistance through activating anti-oxidative signaling pathway, providing new insights into the protective effects of C. lanceolata polysaccharide in metabolic disease.

17 - Role of Intestinal Microbiota in High Fat-High Sucrose Diet-Induced Insulin Resistance in Mice and Beneficial Effect of Saskatoon Berry Powder

Intestinal microbiota plays important roles in diet-induced obesity and type 2 diabetes. The present study examined the impact of Saskatoon berry powder (SBp) on insulin resistance, inflammation and intestinal microbiota in diet-induced obese mice. Male C57 BL/6J mice were fed control diet, high fat-high sucrose (HFHS) diet or HFHS+5% SBp (HFHS+B) diet for 15 weeks. The composition of fecal bacterial community was characterized using the Illumina sequencing of V4 region of 16S rRNA gene. HFHS diet increased body weight, fasting plasma glucose, cholesterol, triglycerides, insulin, homeostatic model assessment-insulin resistance, monocyte adhesion, tumor necrosis factor-α, plasminogen activator inhibitor-1, monocyte chemotactic protein-1, intracellular cell adhesion molecule-1, urokinase plasminogen activator and its receptor in plasma or aortae compared to the control diet. HFHS+B diet postponed the increase in body weight, suppressed HFHS diet-induced disorders in the metabolic and inflammatory variables. The ratio of Firmicutes/Bacteroidetes in the HFHS group was higher than that in the control group (p<0.01), and that in the HFHS+B group was lower than that in the HFHS group (p<0.05). The abundances of S24-7 family negatively correlated with body weight and all tested metabolic or inflammatory variables. The results suggest that SBp attenuates HFHS diet-induced metabolic disorders, vascular inflammation and imbalance in gut microbiota in mice.

P737Endothelial ERK2/thromboxane receptor pathway induces endothelial dysfunction, insulin resistance and steatohepatosis through superoxide with high fat high sucrose diet

Abstract Introduction Metabolic syndrome (MetS) is well known as the risk of cardiovascular diseases associated with endothelial dysfunction and induces steatohepatosis. Insulin resistance is a major character of MetS, which affects intracellular signaling pathways and endothelial function. Extracellular signal-regulated kinase (ERK) is a major component of insulin signal and many of vasoactive peptides, which were released in MetS, can activate it in endothelium. However, the role of endothelial ERK in nitric oxide (NO) bioactivity in MetS in in vivo has been unknown. Purpose The aim of this study is to clarify the role of endothelial ERK2 on NO bioactivity in mice model of MetS. Methods and results We created endothelial specific ERK2 knock out mice (EE2KO) crossing Tie2-Cre mice and ERK2 flox mice and fed them with normal or high-fat/high-sucrose diet (HFHSD) for 24 weeks. Serum glucose and insulin levels and HOMA-IR were lowered in EE2KO with HFHSD without changing body weight. In wild type mice (WT) with HFHSD, nonalcoholic fatty liver disease (NAFLD) activity score, fibrosis score and serum ALT level were increased, all of which were blunted in EE2KO. EE2KO with HFHSD lowered systolic blood pressure (WT: 123.7±5.83 mmHg, EE2KO: 101.4±3.66 mmHg, P&lt;0.01, N=8) without changing heart rate, which was increased to the same levels with L-NAME, an endothelial NO synthase inhibitor, in both groups. Serum NO levels measured with serum nitrite/nitrate concentrations were increased in EE2KO with HFHSD (WT: 23.10±3.74 μmol/l, EE2KO: 41.71±6.73 μmol/l, P&lt;0.05, N=12). Endothelial function was assessed with the isometric tension measurement of aortic rings with acetylcholine (ACh). ACh-induced relaxation was improved in EE2KO with HFHSD. Superoxide production of aorta from EE2KO was lowered than WT with HFHSD in dihydroethidium (DHE) staining. S18886, an antagonist of the thromboxane A2-prostanoid (TP) receptor, decreased superoxide production of aorta in DHE staining resulting in improving endothelial function in the isometric tension measurement of aortic rings. Oral administrations of S18886 decreased systolic blood pressure, serum fasting glucose and insulin levels, and surprisingly improved steatohepatosis by decreasing NAFLD activity score and fibrosis score. Relaxation of aortic rings with ACh Conclusions Endothelial ERK2/TP receptor pathway increases superoxide production and decreased NO bioactivity, resulting in deteriorating endothelial function, insulin resistance and steatohepatosis, which were improved by antagonist of the TP receptor in mice model of MetS. The present study indicates that ERK2/TP pathway could be a therapeutic target for complications of MetS.

Vitamin D Supplementation Reduces Serum Chemerin Level in Gestational Diabetes Mellitus Rat Model

AbstractBackground: Gestational Diabetes Mellitus (GDM) is the most common metabolic disorder that increases the prenatal morbidity. Data regarding the association between circulating chemerin level and GDM remains controversial. On the other hand, Vitamin D deficiency is common in pregnancy and may increase the frequency of GDM.Aim of Study: This study was conducted to examine the effects of Vitamin D3 supplementation on serum chemerin level and some metabolic parameters in GDM rat model.Material and Methods: Healthy female white albino rats were divided randomly into three groups (n=10 rats): Group I (normal pregnant group); fed on normal diet for five weeks before induction of pregnancy. Group II (GDM-induced); fed High Fat-Sucrose Diet (HFSD) for five weeks before induction of pregnancy then injected Intraperitoneally (I.P) by Strepto-zotocin (STZ) (25mg/kg) on the 7th day of gestation. Group III (GDM-induced group supplemented with Vitamin D3); GDM-induced as before and injected Intramuscularly (I.M) with 20,000IU/kg of cholecalciferol on days 1 and 14 of gestation. On the 19th day of gestation, serum chemerin, estradiol, progesterone, glucose, insulin and Insulin Resistance index (HOMA-IR), Total Cholesterol (TC), Triglycerides (TG), Low Density Lipoprotein-cholesterol (LDL-c), High Density Lipoprotein-cholesterol (HDL-c), Very Low Density Lipoprotein-cholesterol (VLDL-c), Tumor Necrosis Factor alpha (TNF a) and Malondialdehyde (MDA) levels and Serum Superoxide Dismutase (SOD) activity were estimated for all groups.Results: GDM-induced rats showed significantly increased serum glucose, HOMA-IR, TG, TC, LDL-c, VLDL-c, MDA, and TNF a levels while showed significantly decreased serum insulin and HDL-c levels and SOD activity when compared to normal pregnant control rats. GDM-induced rats also showed significantly increased serum chemerin levels that showed significant positive correlations with serum glucose, insulin, HOMA-IR, TG, TC, LDL-c, VLDL-c, MDA, and TNF a levels but showed significant negative correlations with serum HDL-c level and SOD activity. Noteworthy, Vitamin D3 administration significantly improved these pa-rameters in GDM-induced group supplemented with Vitamin D3.Conclusion: Our results denoted the protective effect of Vitamin D3 supplementation on GDM that may be through improving the antioxidant and inflammatory status. Decreasing circulating chemerin level may play a role in this protective effect.

Genetic determinants of gut microbiota composition and bile acid profiles in mice.

The microbial communities that inhabit the distal gut of humans and other mammals exhibit large inter-individual variation. While host genetics is a known factor that influences gut microbiota composition, the mechanisms underlying this variation remain largely unknown. Bile acids (BAs) are hormones that are produced by the host and chemically modified by gut bacteria. BAs serve as environmental cues and nutrients to microbes, but they can also have antibacterial effects. We hypothesized that host genetic variation in BA metabolism and homeostasis influence gut microbiota composition. To address this, we used the Diversity Outbred (DO) stock, a population of genetically distinct mice derived from eight founder strains. We characterized the fecal microbiota composition and plasma and cecal BA profiles from 400 DO mice maintained on a high-fat high-sucrose diet for ~22 weeks. Using quantitative trait locus (QTL) analysis, we identified several genomic regions associated with variations in both bacterial and BA profiles. Notably, we found overlapping QTL for Turicibacter sp. and plasma cholic acid, which mapped to a locus containing the gene for the ileal bile acid transporter, Slc10a2. Mediation analysis and subsequent follow-up validation experiments suggest that differences in Slc10a2 gene expression associated with the different strains influences levels of both traits and revealed novel interactions between Turicibacter and BAs. This work illustrates how systems genetics can be utilized to generate testable hypotheses and provide insight into host-microbe interactions.

Ameliorative effect of fermented Pentaclethra macrophylla (African oil bean seed) on high fat diet and sucrose drink induced metabolic syndrome in male New Zealand rabbits.

The consumption of nutraceuticals has become progressively popular in improving health, as well as disease treatment and prevention. The aim of this study is to evaluate the ameliorative effect of fermented Pentaclethra macrophylla (African oil bean) seed on high fat diet and sucrose drink induced metabolic syndrome in male New Zealand rabbits. All experimental procedures were carried using standard methods. A total of twenty (20) rabbits were used for this study, the animals were randomly grouped into five (5) groups with four (4) animals each. Metabolic syndrome risk factors obesity, hypertension, dyslipidemia and hyperglycemia were determined. HFD+30%SUC had over 1500g body weight (bwt) and fasting blood sugar (FBS) 239.50±5.74 mg/dl relative to the normal control with 1000±6.73g and 77.00±5.94 respectively whereas ND+30%SUC had lower FBS (l172.50±2.52) compared to HFD+30%SUC. There was a significant p&lt;0.05 increase in body weights in treated groups with 1274±11.19g, 1282.75±4.99g, 1285±4.76g and FBS levels in mg/dL198.25±4.79, 198.75±8.06, 200±3.74 in rabbits compared to untreated HFD+30%SUC. Glycated hemoglobin, and ?-Amylase were significantly p&lt;0.05 elevated, glucose-6-phosphate dehydrogenase levels were significantly p&lt;0.05 reduced, lipid profile markers (HDL, TRIG &amp; CHOL), electrolytes (sodium, potassium, calcium), urea and creatinine levels were significantly p&lt;0.05 altered in HFD+30%SUC exposed group relative to the normal control and ND+30%SUC. However, dietary supplementation with fermented Pentaclethra macrophylla seeds caused weight, FBS, serum lipid reduction and potentiated electrolyte, urea and creatinine levels. Therefore, according to our results, fermented Pentaclethra macrophylla seed is an excellent nutraceutical and its consumption should be encouraged in modifying high fat and elevated intake of sucrose in rabbit

Liraglutide improves insulin sensitivity in high fat diet induced diabetic mice through multiple pathways

Glucagon like peptide-1 (GLP-1) promotes postprandial insulin secretion. Liraglutide, a full agonist of the GLP-1 receptor, reduces body weight, improve insulin sensitivity, and alleviate Non Alcoholic Fatty Liver Disease (NAFLD). However, the underlying mechanisms remain unclear. This study aims to explore the underlying mechanisms and cell signaling pathways involved in the anti-obesity and anti-inflammatory effects of liraglutide.Mice were fed a high fat high sucrose diet to induce diabetes, diabetic mice were divided into two groups and injected with liraglutide or vehicle for 14 days. Liraglutide treatment improved insulin sensitivity, accompanied with reduced expression of the phosphorylated Acetyl-CoA carboxylase-2 (ACC2) and upregulation of long chain acyl CoA dehydrogenase (LCAD) in insulin sensitive tissues. Furthermore, liraglutide induced adenosine monophosphate-activated protein kinase-α (AMPK-α) and Sirtuin-1(Sirt-1) protein expression in liver and perigonadal fat. Liraglutide induced elevation of fatty acid oxidation in these tissues may be mediated through the AMPK-Sirt-1 cell signaling pathway. In addition, liraglutide induced brown adipocyte differentiation in skeletal muscle, including induction of uncoupling protein-1 (UCP-1) and PR-domain-containing-16 (PRDM-16) protein in association with induction of SIRT-1. Importantly, liraglutide displayed anti-inflammation effect. Specifically, liraglutide led to a significant reduction in circulating interleukin-1 β (IL-1 β) and interleukin-6 (IL-6) as well as hepatic IL-1 β and IL-6 content. The expression of inducible nitric oxide synthase (iNOS-1) and cyclooxygenase-2 (COX-2) in insulin sensitive tissues was also reduced following liraglutide treatment. In conclusion, liraglutide improves insulin sensitivity through multiple pathways resulting in reduction of inflammation, elevation of fatty acid oxidation, and induction of adaptive thermogenesis.

Abstract 276: Maternal High Fat, High Sucrose Diet-induced Cardiac Mitochondrial Abnormalities in the Offspring are Transmitted via the Oocyte Nucleus

Introduction: Maternal obesity correlates with higher cardiovascular disease risk in human offspring. We found high fat, high sucrose (HF/HS) diet results in accretion of abnormal mitochondria in mouse oocytes, and chow-fed offspring of HF/HS-fed dams exhibit transgenerational transmission of abnormal cardiac mitochondria through male and female germlines. Nuclear or mitochondrial inheritance can occur via the female germline, whereas male germline inheritance implicates nuclear epigenetic changes. However, recent reports indicate sperm mitochondria transmission is possible. Whether the mechanism is via effects on the nucleus or germ cell mitochondria is unknown. Hypothesis: Maternal HF/HS-feeding results in cardiac mitochondrial dysfunction in offspring due to effects on the oocyte nucleus. Methods: C57BL/6 female mice were chow- or HF/HS-fed, and mated to chow-fed C57BL/6 males. Female pronuclei were exchanged between embryos obtained from chow- and HF/HS-fed dams. Embryos without pronuclear transfer were additional controls. All embryos were transferred into chow-fed ICR dams. Cardiac mitochondrial structure (transmission electron microscopy) and function (high-resolution respirometry) were evaluated in 12-week-old offspring. Results: Adult offspring born of embryos having maternal pronuclei from chow-fed dams and ooplasm from chow- or HF/HS-fed dams had mitochondrial structure or oxygen consumption levels comparable to offspring born of control chow-fed dam embryos. In contrast, offspring born from embryos with maternal pronuclei from HF/HS-fed dams and ooplasm from chow-fed dams had abnormal cardiac mitochondrial structure (round shape, cristal rarefaction) and reduced oxygen consumption (~40%), comparable to embryo transfer offspring of HF/HS-fed dams. Conclusion: Shown for the first time, abnormal cardiac mitochondria in obese dam offspring result from HF/HS diet effects on the oocyte nucleus (likely epigenetic changes during oogenesis). Elucidating diet/obesity-induced oocyte epigenetic changes, and the mechanisms for induction and transgenerational transmission, could enable therapies to target inheritable heart disease risk in humans.

Abstract 746: The Effect of Aging-related Metabolic Disorder on Resistin Expression and Valvular Heart Disorder

Calcific aortic valve stenosis (AS) is the most prevalent valvular heart disease and the third most frequent cardiovascular disease after coronary artery disease and hypertension. AS is characterized by a period of asymptomatic progressive valve calcification, which eventually leads to the development of a severe stenosis and to the onset of symptoms. Visceral obesity is a strong predictor of type-2 diabetes and is associated with insulin resistance. In addition, increased visceral adiposity leads to an increase in systemic release in resistin (Retn) and possibly interleukins. Elevation of circulating adipokines such as Retn plays a role in the development of muscle insulin resistance. Moreover, higher Retn levels were associated with increased valvular inflammation and calcification in the elderly patients, whereas this association was not observed among middle-aged patients. In the current study, we explored the potential role of Retn in ectopic valvular calcification. Analyses of scanning electron microscopy micrographs of calcified aortic valve showed that Retn is more abundant next to calcified nodes. These data corroborate with increased levels of circulating Retn in apoE mice that were fed a high fat high sucrose diet for 24 weeks. Moreover, apoE-/-Retn-/- double KO mutant mice have lower plasma cholesterol level compared to apoE KO mice. In addition, knocking down Retn decreased valve lipid infiltration, lowered glycaemia, calcium nodes and reduced fibrosis. In conclusion, Retn may be a new pharmacological target to stop the progression of aortic stenosis in patients with visceral obesity.

Effects of Recombinant Irisin on Body Mass Index, Serum Insulin, Luteinizing Hormone and Testosterone Levels in Obese Female BALB/c Mice.

To determine the effects of recombinant irisin on body mass index (BMI), serum insulin, luteinizing hormone (LH) and testosterone levels, and to correlate the serum insulin levels with serum luteinizing hormone and testosterone levels and to correlate the body mass index with serum insulin levels in obese female BALB/c mice. Laboratory-based experimental study. Department of Physiology, Shifa College of Medicine, Islamabad in collaboration with Research Laboratory of Shifa College of Medicine, National Institute of Health (NIH) and Reproductive Physiology Laboratory, Quaid-e-Azam University, Islamabad, from March 2015 to September 2016. Ninety female BALB/c mice were divided into three equal groups. Group A which was the control group was fed with normal chow diet. Group B and Group C were fed with high fat-high sucrose (HF-HS) diet for five weeks to induce obesity. After four weeks group C was divided into two subgroups. Group C-low dose (LD) was injected with low dose irisin and group C-High dose (HD) was injected with high dose irisin for one week. After five weeks, the BMI, serum insulin, LH and testosterone levels were measured in all the groups. Data was analysed by SPSS version 21. P-value of <0.05 was considered significant. Group B showed statistically significant elevation in BMI, serum insulin, LH and testosterone levels as compared to Group A (p <0.001, <0.001, 0.007 and 0.014, respectively). Group C-HD showed statistically significant decrease in BMI, serum insulin, and LH as compared to Group B (p <0.001, 0.013 and 0.028, respectively). Serum testosterone level was also decreased in group C-HD as compared to Group B, however the difference was not significant. Obesity increases the serum insulin, LH and testosterone and irisin significantly lowers the elevated BMI, serum insulin and LH levels in female BALB/c mice. It also lowers the elevated testosterone levels, but not significantly.

The nuclear and mitochondrial sirtuins, Sirt6 and Sirt3, regulate each other's activity and protect the heart from developing obesity-mediated diabetic cardiomyopathy.

Sirtuins (Sirts) are implicated in regulating a myriad of biologic functions ranging from cell growth and metabolism to longevity. Here, we show that nuclear Sirt, Sirt6, and mitochondrial Sirt, Sirt3, regulate each other's activity and protect the heart from developing diabetic cardiomyopathy. We found that expression of both Sirt6 and Sirt3 was reduced in cardiomyocytes treated with palmitate and in hearts of mice fed with a high-fat, high-sucrose (HF-HS) diet to develop obesity and diabetes. Conversely, whole-body overexpressing Sirt6 transgenic (Tg.Sirt6) mice were protected from developing obesity and insulin resistance when fed with the same HF-HS diet. The hearts of Tg.Sirt6 mice were also protected from mitochondrial fragmentation and decline of Sirt3, resulting otherwise from HF-HS diet feeding. Mechanistic studies showed that Sirt3 preserves Sirt6 levels by reducing oxidative stress, whereas Sirt6 maintains Sirt3 levels by up-regulating nuclear respiratory factor 2 (Nrf2)-dependent Sirt3 gene transcription. We found that Sirt6 regulates Nrf2-mediated cardiac gene expression in 2 ways; first, Sirt6 suppresses expression of Kelch-like ECH-associated protein 1 (Keap1), a negative regulator of Nrf2, and second, Sirt6 binds to Nrf2 and antagonizes its interaction with Keap1, thereby stabilizing Nrf2 levels in cardiomyocytes. Together, these studies demonstrate that Sirt6 and Sirt3 maintain each other's activity and protect the heart from developing diabetic cardiomyopathy.-Kanwal, A., Pillai, V. B., Samant, S., Gupta, M., Gupta, M. P. The nuclear and mitochondrial sirtuins, Sirt6 and Sirt3, regulate each other's activity and protect the heart from developing obesity-mediated diabetic cardiomyopathy.

Estrogen withdrawal and replacement differentially target liver and adipose tissues in female mice fed a high-fat high-sucrose diet: impact of a chronic exposure to a low-dose pollutant mixture☆

Postmenopausal women may be at particular risk when exposed to chemicals especially endocrine disruptors because of hormonal deficit. To get more insight, ovariectomized C57Bl6/J mice fed a high-fat high-sucrose diet were chronically exposed from 5 to 20 weeks of age to a low-dose mixture of chemicals with one dioxin, one polychlorobiphenyl, one phthalate and bisphenol A. Part of the mice received as well E2 implants to explore the potential estrogenic dependency of the metabolic alterations. With this model, estrogen loss resulted in glucose but not lipid metabolism impairment, and E2 replacement normalized the enhanced body and fat pad weight, and the glucose intolerance and insulin resistance linked to ovariectomy. It also altered cholesterol metabolism in the liver concurrently with enhanced estrogen receptor Esr1 mRNA level. In addition, fat depots responded differently to estrogen withdrawal (e.g., selective mRNA enhancement of adipogenesis markers in subcutaneous and of inflammation in visceral fat pads) and replacement challenges. Importantly, the pollutant mixture impacted lipid deposition and mRNA expression of several genes related to lipid metabolism but not Esr1 in the liver. Adiponectin levels were altered as well. In addition, the mRNA abundance of the various estrogen receptors was regionally impacted in fat tissues. Besides, xenobiotic processing genes did not change in response to the pollutant mixture in the liver. The present findings bring new light on estrogen-dependent metabolic alterations with regards to situations of loss of estrogens as observed after menopause.

Developmental origins of ovarian disorder: impact of maternal lean gestational diabetes on the offspring ovarian proteome in mice†.

Gestational diabetes mellitus (GDM) is an obstetric disorder affecting approximately 10% of pregnancies. The four high-fat, high-sucrose (HFHS) mouse model emulates GDM in lean women. Dams are fed a HFHS diet 1 week prior to mating and throughout gestation resulting in inadequate insulin response to glucose in mid-late pregnancy. The offspring of HFHS dams have increased adiposity, thus, we hypothesized that maternal metabolic alterations during lean GDM would compromise ovarian function in offspring both basally and in response to a control or HFHS diet in adulthood. Briefly, DLPL were lean dams and control diet pups; DLPH were lean dams and HFHS pups; DHPL were HFHS dams and control diet pups; and DHPH were HFHS dams and HFHS pups. A HFHS challenge in the absence of maternal GDM (DLPL vs. DLPH) increased 3 and decreased 30 ovarian proteins. Maternal GDM in the absence of a dietary stress (DLPL vs. DHPL) increased abundance of 4 proteins and decreased abundance of 85 proteins in the offspring ovary. Finally, 87 proteins increased, and 4 proteins decreased in offspring ovaries due to dietary challenge and exposure to maternal GDM in utero (DLPL vs. DHPH). Canopy FGF signaling regulator 2, deleted in azoospermia-associated protein 1, septin 7, and serine/arginine-rich splicing factor 2 were altered across multiple offspring groups. Together, these findings suggest a possible impact on fertility and oocyte quality in relation to GDM exposure in utero as well as in response to a western diet in later life.

Puerarin protects against high-fat high-sucrose diet-induced non-alcoholic fatty liver disease by modulating PARP-1/PI3K/AKT signaling pathway and facilitating mitochondrial homeostasis.

As yet, there was no effective pharmacological therapy approved for non-alcoholic fatty liver disease (NAFLD). Here, we aimed to evaluate the therapeutic potential of puerarin against NAFLD and explored the underlying mechanisms. C57BL/6J mice were fed with a high-fat high-sucrose (HFHS) diet with or without puerarin coadministration intragastrically. The levels of hepatocellular injury, steatosis, fibrosis, and mitochondrial and metabolism alteration were detected. First, puerarin ameliorated histopathologic abnormalities due to HFHS. We observed a marked increase in hepatic lipid content, inflammation, and fibrosis level, which were attenuated by puerarin. Possible mechanisms were related to puerarin-mediated activation of PI3K/AKT pathway and further improvement in fatty acid metabolism. Puerarin restored the NAD+ content and beneficially affected the hepatic mitochondrial function, which attenuated HFHS-induced steatosis and metabolic disturbances. Finally, hepatic PARP-1 was activated due to excessive fat intake. Puerarin attenuated the PARP-1 expression in HFHS-fed mice, and PJ34, the PARP inhibitor, could mimic these protections of puerarin. However, pharmacological inhibition of PI3K disabled the protection of puerarin or PJ34 toward NAD+ refilling and mitochondrial homeostasis. In conclusion, our findings indicated that puerarin could be a promising and practical therapeutic strategy in NAFLD through modulating PARP-1/PI3K/AKT signaling pathway and further facilitating mitochondrial function.