We have shown that prenatal low-protein (LP) followed by postnatal high-fat (HF) diets result in a rapid increase in subcutaneous adipose tissue (subc-AT) mass in the offspring, contributing to development of obesity and insulin resistance. Studies have shown that a key transcription factor, PR domain containing 16 (PRDM16), and fibroblast growth factor 21 (FGF21) are involved in conversion of precursor cells into mitochondria (mt)-enriched beige adipocytes (BA). Our hypothesis is that a maternal LP and postnatal HF diets increase the risk of obesity and insulin resistance in offspring, in part, by reducing the conversion of precursor cell into BA in the subc-AT of offspring.
View Article and Find Full Text PDFBackground: There is a growing interest in exploiting the induction of beige or "brite" (brown in white) adipocytes (beigeing) to combat obesity and its comorbidities. However, there is some uncertainty regarding the best markers to evaluate the occurrence or magnitude of beigeing in white adipose tissue in the mouse model.
Methods: We evaluated the transcript expression of several thermoregulatory genes and proposed beige markers employing cell culture, whole white adipose tissue, and the adipocyte and stromal vascular fractions.
Consumption of a high-fat diet causes an increase in bile acid deoxycholic acid (DCA) in colon lumen and colon cancer risk, while butyrate, an intestinal microbiota metabolite of dietary fiber, has been shown to exhibit colon cancer-preventive effects. To distinguish these opposing effects of DCA and butyrate (two major metabolites in colon lumen), we examined the effects of physiologically relevant doses of butyrate (0.5-2 mmol/l) and DCA (0.
View Article and Find Full Text PDFBrown adipose tissue (BAT) plays an important role in regulating body weight (BW) by modifying thermogenesis. Maternal low protein (LP) diets reduce offspring birth weight. Increased BAT thermogenesis in utero may be one mechanism for the lower BW.
View Article and Find Full Text PDFStudies have demonstrated that epigenetic changes such as DNA methylation, histone modification, and chromatin remodeling are linked to an increased inflammatory response as well as increased risk of chronic disease development. A few studies have begun to investigate whether dietary nutrients play a beneficial role by modifying or reversing epigenetically induced inflammation. Results of these studies show that nutrients modify epigenetic pathways.
View Article and Find Full Text PDFMalnutrition during the fetal growth period increases risk for later obesity and type 2 diabetes mellitus (T2DM). We have shown that a prenatal low-protein (8% protein; LP) diet followed by postnatal high-fat (45% fat; HF) diet results in offspring propensity for adipose tissue catch-up growth, obesity and T2DM in Sprague-Dawley rats. Skeletal muscle is the major tissue for insulin-mediated glucose uptake.
View Article and Find Full Text PDFGiven the role that diet and other environmental factors play in the development of obesity and type 2 diabetes, the implication of different epigenetic processes is being investigated. Although it is well known that external factors can cause cell type-dependent epigenetic changes, including DNA methylation, histone tail modifications, and chromatin remodeling, the regulation of these processes, the magnitude of the changes and the cell types in which they occur, the individuals more predisposed, and the more crucial stages of life remain to be elucidated. There is evidence that obese and diabetic people have a pattern of epigenetic marks different from nonobese and nondiabetic individuals.
View Article and Find Full Text PDFEpigenetics can be defined as inheritable and reversible phenomena that affect gene expression without altering the underlying base pair sequence. Epigenomics is the study of genome-wide epigenetic modifications. Because gene expression changes are critical in both normal development and disease progression, epigenetics is widely applicable to many aspects of biological research.
View Article and Find Full Text PDFWe investigated the effects of diet (AIN93G or high-fat), physical activity (sedentary or voluntary running), and protein source (casein or soy protein isolate (SPI)) and their interactions on metabolic disturbance and inflammation in mice. After 14 weeks of feeding, the high-fat diet increased body weight gain by 34.5% (p < 0.
View Article and Find Full Text PDFMaternal low-protein diets result in lower birth weight followed by accelerated catch-up growth that is accompanied by the development of obesity and glucose intolerance in later life. Whether postnatal high-fat (HF) diets further contribute to the development of obesity and insulin resistance in offspring by affecting adipose tissue metabolism and DNA methylation is currently unknown. Obese-prone Sprague-Dawley rats were fed 8% low protein (LP) or 20% normal protein diets for 3 wk prior to conception and throughout pregnancy and lactation to investigate whether prenatal LP and postnatal HF diets affect the rate of adipose tissue growth, insulin-like growth factor 2 (Igf2) expression, and DNA methylation in male offspring.
View Article and Find Full Text PDFBackground: Leptin-deficient ob/ob mice exhibit adipocyte hypertrophy and hyperplasia as well as elevated adipose tissue and systemic inflammation. Multipotent stem cells isolated from adult adipose tissue can differentiate into adipocytes ex vivo and thereby contribute toward increased adipocyte cell numbers, obesity, and inflamm ation. Currently, information is lacking regarding regulation of adipose stem cell numbers as well as leptin-induced inflammation and its signaling pathway in ob/ob mice.
View Article and Find Full Text PDFStudies have shown positive correlations between inflammatory cytokines such as interleukin-6 (IL-6) and the development of chronic diseases including cardiovascular disease by activating C-reactive protein (CRP). Both atorvastatin calcium (lipitor) as well as flavonoid rich fruit such as tart cherry demonstrate potent anti-inflammatory effects on IL-6 secretion. In this study, we investigated whether tart cherry extract or specific anthocyanins contained in the tart cherry show synergistic anti-inflammatory effects with lipitor.
View Article and Find Full Text PDFExcessive secretion of proinflammatory adipokines has been linked to metabolic disorders. We have previously documented anti-inflammatory effects of n-3 polyunsaturated fatty acids (n-3 PUFAs) in adipose tissue; however, the mechanisms by which these fatty acids regulate adipokine secretion remain unclear. Here, we determined differential effects of eicosapentaenoic acid (EPA, n-3 PUFA) vs.
View Article and Find Full Text PDFObesity is associated with the metabolic syndrome, a significant risk factor for developing type 2 diabetes and cardiovascular diseases. Chronic low-grade inflammation occurring in the adipose tissue of obese individuals is causally linked to the pathogenesis of insulin resistance and the metabolic syndrome. Although the exact trigger of this inflammatory process is unknown, adipose tissue hypoxia, endoplasmic reticular stress, and saturated fatty acid-mediated activation of innate immune processes have been identified as important processes in these disorders.
View Article and Find Full Text PDFObesity is a major public health problem in the United States and worldwide. Further, obesity is causally linked to the pathogenesis of insulin resistance, metabolic syndrome and type-2 diabetes (T2D). A chronic low-grade inflammation occurring in adipose tissue is at least in part responsible for the obesity-induced insulin resistance.
View Article and Find Full Text PDFIncreased adipose tissue positively correlates with circulating inflammatory cytokines such as IL-6. We previously reported that adipose stem cells from genetically obese ob/ob mice produce significantly higher levels of IL-6 compared with other cell types such as adipocytes and macrophages within adipose tissue. We also demonstrated that (n-3) PUFA have antiinflammatory effects on adipocyte IL-6 secretion.
View Article and Find Full Text PDFChronic hyperglycaemia is detrimental to pancreatic beta-cells by causing impaired insulin secretion and diminished beta-cell function through glucotoxicity. Understanding the mechanisms underlying beta-cell survival is crucial for the prevention of beta-cell failure associated with glucotoxicity. Autophagy is a dynamic lysosomal degradation process that protects organisms against metabolic stress.
View Article and Find Full Text PDFA dramatic rise in the incidence of obesity in the U.S. has accelerated the search for interventions that may impact this epidemic.
View Article and Find Full Text PDFSerum C-reactive protein (CRP) is a biomarker for chronic inflammation and a sensitive risk factor for cardiovascular diseases. Though CRP has been reported to be related to food intake, there is no documentation of a direct association with flavonoid intake. We aimed to test the associations between dietary flavonoid intake and serum CRP concentrations among U.
View Article and Find Full Text PDFAm J Physiol Endocrinol Metab
November 2007
Studies showed that monocyte chemotactic protein-1 (MCP-1) concentrations are increased in obesity. In our current study, we demonstrate that plasma MCP-1 level in leptin-deficient ob/ob mice is significantly higher than in lean mice. Furthermore, we determined that basal adipose tissue MCP-1 mRNA levels are significantly higher in ob/ob mice compared with lean mice.
View Article and Find Full Text PDFInflammation plays a major role in the development of chronic diseases such as cardiovascular disease and Type 2 diabetes. Further, it was demonstrated that obese animals and humans have significantly higher levels of circulating proinflammatory cytokines, such as interleukin-6 (IL-6). The aim of this study was to determine whether adipose tissue could be a major source of circulating IL-6 in leptin-deficient obese (ob/ob) mice by comparing the expression of IL-6 in different tissues of ob/ob mice.
View Article and Find Full Text PDFPreviously, we showed that macrophages (MØ) from old mice have significantly higher levels of lipopolysaccharide (LPS)-induced prostaglandin E(2) (PGE(2)) production than young mice, due to increased cyclooxygenase-2 (COX-2) mRNA levels. The aim of the current study was to determine the underlying mechanisms of age-associated increase in COX-2 gene expression. The results demonstrate that increased COX-2 mRNA expression in the old mice is due to a higher rate of transcription rather than increased stability of COX-2 mRNA.
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