Project description:Resistin has been originally identified as an adipokine that links obesity to insulin resistance in mice. In our previous studies in spontaneously hypertensive rats (SHR) expressing a nonsecreted form of mouse resistin (Retn) transgene specifically in adipose tissue (SHR-Retn), we observed an increased lipolysis and serum free fatty acids, ectopic fat accumulation in muscles and insulin resistance. Recently, brown adipose tissue (BAT) has been suggested to play an important role in the pathogenesis of metabolic disturbances by its ability to dissipate energy excess. In the current study, we analyzed autocrine effects of transgenic resistin on BAT glucose and lipid metabolism and mitochondrial function in the SHR-Retn versus nontransgenic SHR controls. We observed that interscapular BAT isolated from SHR-Retn transgenic rats when compared to SHR controls showed a lower relative weight, significantly reduced both basal and insulin stimulated incorporation of palmitate into BAT lipids, and significantly decreased palmitate oxidation and glucose oxidation. In addition, in vivo microPET imaging revealed significantly reduced 18F-FDG uptake in BAT induced by exposure to cold in SHR-Retn versus control SHR. Gene expression profiles identified differentially expressed genes involved in skeletal muscle and connective tissue developmental and inflammation, as well as MAPK and insulin signaling. These results provide compelling evidence that autocrine effects of resisitin in BAT play an important role in the pathogenesis of insulin resistance in the rat.
Project description:Brown adipose tissue (BAT) was suggested to play an important role in lipid and glucose metabolism in rodents and possibly also in humans. In the current study, we used genetic and correlation analyses in the BXH/HXB recombinant inbred (RI) strains, derived from Brown Norway (BN) and spontaneously hypertensive rats (SHR), to identify genetic determinants of BAT function and its role in the pathogenesis of metabolic disturbances. Linkage analyses revealed significant quantitative trait locus (QTL) associated with interscapular BAT mass in the vicinity of the Cd36 (fatty acid translocase) gene on chromosome 4. Additional two closely linked QTL asociated with glucose oxidation and incorporation into BAT lipids were detected near the Wars2 (tryptophanyl tRNA synthetase 2, mitochondrial) candidate gene on chromosome 2.
Project description:Recently, red beetroot has attracted attention as a health promoting functional food. Studies showed that beetroot administration can reduce blood pressure and ameliorate parameters of glucose and lipid metabolism, however, mechanisms underlying these beneficial effects of beetroot are not fully understood. In the current study, we analyzed effects of beetroot on parameters of glucose and lipid metabolism in two models of metabolic syndrome, (i) transgenic spontaneously hypertensive rats expressing human C-reactive protein (SHR-CRP rats), and (ii) hereditary hypertriglyceridemic (HHTg) rats. Treatment with beetroot juice for 4 weeks was in both models associated with amelioration of oxidative stress, reduced circulating lipids, smaller visceral fat depots, and lower ectopic fat accumulation in the liver, compared to their respective untreated controls. On the other hand, beetroot treatment had no significant effects on sensitivity of muscle and adipose tissue to insulin action in both models. Analyses of hepatic proteome revealed significantly deregulated proteins involved in glycerophospholipid metabolism, mTOR signalling, inflammation, and cytoskeleton rearrangement.
Project description:Here, we investigated whether prenatal exposure to nicotine alters kidney glomerular mass and genome-wide gene expression profiles in two genetically distant strains of rats, namely spontaneously hypertensive rats (SHR) and Brown Norway (BN) rats. Nicotine or saline were administered to BN and SHR dams via osmotic pumps throughout gestation. Kidneys from 9-week-old male offspring were studied.
Project description:Left ventricle gene expression was analyzed in three models of hypertension in order to clarify the molecular mechanisms associated with left ventricular hypertrophy. Transgenic heterozygous TGR(mRen2)27 rats, overexpressing the mouse renin gene, and their littermate negative controls, spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY), and Lyon hypertensive rats (LH) and their normotensive controls (LL) were included in the study.
Project description:We compared tissue Na+ storage in salt sensitive spontaneously hypertensive rats (SHR) versus salt resistant normotensive Brown Norway (BN) rats after salt loading (10 days drinking 1% NaCl solution), the SHR showed significant parallel increase in osmotically inactive Na+ storage in the skin while no significant changes in skin electrolyte concentrations were observed in BN rats. SHR rats after salt treatment exhibited a nonsignificant decrease in skin blood capillary number (rarefaction) while BN rats showed significantly increased skin blood capillary density. Analysis of dermal gene expression profiles in BN rats after salt treatment showed significant up-regulation of genes involved in angiogenesis and proliferation of endothelial cells contrary to the SHR.
Project description:We used lncRNA-mRNA micro-array to analyze the transcriptome in the thoracic aorta tissue of 24 wees-old WKY and spontaneously hypertensive rats (SHRs).
Project description:Type 2 diabetes (T2D) is characterized by hyperglycaemia and defects in insulin secretion and action at target tissues. Using the Illumina RatRef-12 v1.0 array, gene expression was assessed in two insulin-target tissues (liver and adipose tissue) from seven-month-old spontaneously diabetic (Goto-Kakizaki [GK]) and non-diabetic (Brown-Norway [BN]) rats. This study was performed in parallel with miRNA expression profiling of the same rats.
Project description:We investigated morphometric structure and gene expression by microarray analysis in a small diameter artery, branch of the saphenous artery (a resistance artery), in representative models of renin-angiotensin system (RAS)-dependent and glucocorticoid hypertension, using the spontaneously hypertensive rat (SHR) and adrenocorticotropic hormone (ACTH)-induced hypertensive rat, respectively. Sixteen-week-old male Wistar-Kyoto (WKY) and age-matched spontaneously hypertensive rats (SHR) were used. Keywords: Comparison of global gene expression in resistance arteries of normotensive and genetically hypertensive rats and ACTH-treated rats.
Project description:Effects of voluntary exercise in rat aorta. Spontaneously hypertensive rats (SHR) performed 5 weeks of voluntary exercise (wheel-cage running). Aortic tissue was collected and samples were pooled (3 aortae/chip). Aortae from running rats were compared to aortae from non-running rats. Keywords: parallel sample