Project description:Over-expression of human angiotensin-II receptor type1 (hAT1R) may cause pathological outcomes due to overactivation of renin-angiotensin system. Transgenic (TG) mice containing Hap-I (hypertensive genotype) of human hAT1R gene are more prone to develop metabolic syndrome disorders as compared to TG mice with Hap-II (normotensive genotype). This gene variant associated risk of hypertension together with Western diet and aging may lead to renal disorders. However, mechanisms underlying this process are not well examined. For this purpose, we studied the renal gene expression alterations in aged TG mice containing either Hap-I or Hap-II of hAT1R gene. Aged mice (20-24 months of age) were maintained on a regular diet or high fat diet with 2% NaCl (Western diet, WD) for 16 weeks. On a regular diet, aged Hap-I mice presented higher (~9 mmHg) systolic blood pressure with respect to age-matched Hap-II animals. Following administration of Western diet, blood pressure increased in both groups of mice, but to a larger extent in Hap-I animals (~15 mmHg in comparison to ~7 mmHg in Hap-II). Aged Hap-I mice on Western diet showed increased renal fibrosis. RNA-seq data from renal tissue of Hap-I aged mice revealed that WD significantly altered the expression of >400 genes (p-adj. <0.05). Bioinformatics analysis (Qiagen IPA software) identified major alterations in main canonical pathways involved in renal function and oxidative damage. These changes in turn resulted in kidney failure, renal tubular injury, and renal proliferation. In addition, post WD treatment, RNA seq. analysis from Hap-I and Hap-II kidneys also reveals haplotype specific regulation of genes associated with blood pressure regulation and kidney disorders. Overall, these results indicate that Western diet promotes hypertension and fibrosis in the kidneys of aged mice. These alterations are paralleled by perturbation of renal transcriptional profile. Overall, these studies will assist in the identification of novel mechanisms and molecules involved in hypertension and associated kidney pathophysiology.

Project description:To profile the expression of circulating miRNAs in a mouse model of diet-induced obesity (DIO) with subsequent weight-reduction with low-fat diet (LFD), eighteen C57BL/6 male mice were grouped into three subgroups as: (1) Control: the mice fed with the standard AIN-76A (fat: 11.5 kcal%) diet for 12 wks; (2) DIO: the mice fed with 58 kcal% high-fat diet for 12 wks; (3) DIO+LFD: the mice fed with high-fat diet for 8 wks to induce obesity, then changed to 10.5 kcal% low-fat diet for subsequent 4 wks. C57BL/6 mice were purchased from BioLasco (Taipei, Taiwan). All housing conditions were maintained, and surgical procedures, including analgesia, were performed in an Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC)-accredited SPF facility according to national and institutional guidelines. In this experiment, eighteen C57BL/6 wild type male mice were randomly grouped into three subgroups (n=6 in each group): (1) Control: the control mice were fed ad libitum a standard AIN-76A (fat: 11.5 kcal%) diet for 12 wks; (2) DIO: the mice were fed ad libitum a 58 kcal% HFD (D12331; Research Diets Inc., New Brunswick, NJ) for 12 wks to induce obesity; (3) DIO+LFD: the mice fed ad libitum a 58 kcal% HFD (D12331) for 8 wks to induce obesity, then continued the feeding of 10.5 kcal% LFD (D 12329; Research Diets Inc.) for additional 4 wks. Weight measurements were performed on a weekly basis to for these three groups of mice. Evaluation of blood glucose levels was performed at the beginning and in the end of the experiment to confirm that the HFD-fed mice developed an obese and insulin resistant phenotype. After the end of experiment at 12w, all mice were killed. The abdominal WAT of each mice was removed and weighted. Paraffin-embedded abdominal WAT was sectioned at 5 M-NM-<m and stained with hematoxylin and eosin to measure mean adipocyte area. A volume of 1 mL of whole blood was collected into a plain tube and allowed to clot for 1 hour. The sera samples were aliquoted after centrifugation at 3,000 M-CM-^W g for 10 minutes and stored at M-bM-^HM-^R80M-BM-0C until further analysis.

Dataset Information

Global analysis of kidney gene expression by RNA-Seq of aged CTRP1-deficient mice on high-fat diet

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