Type 2 Diabetes mellitus: mRNA and miRNA profiling
ABSTRACT: This SuperSeries is composed of the following subset Series: GSE21321: Blood microRNA profiles and upregulation of hsa-miR-144 in males with type 2 diabetes mellitus. GSE26167: MicroRNA 144 impairs insulin signaling by inhibiting the expression of insulin receptor substrate 1 in Type 2 Diabetes mellitus Refer to individual Series
Project description:Dysregulation in expression of microRNAs (miRNAs) in various tissues has been linked to a wide spectrum of diseases, including Type 2 Diabetes mellitus (T2D). In this study, we compared the expression profiles of miRNAs in blood samples from Impaired Fasting Glucose (IFG) and T2D male patients with tissues from T2D rat models. Healthy adult males with no past history of T2D (n=158) and with desirable cholesterol and blood pressure profiles were enrolled in this study. They were then classified according to fasting glucose levels to have T2D, IFG or as healthy controls (CTL), for comparison of miRNA expression profiles. Employing miRNA microarray, we identified ‘signature miRNAs’ in peripheral blood samples that distinguished IFG and T2D. Eight selected miRNAs were further validated using stem-loop real-time RT-PCR. miR-144 expression was found to be dysregulated in Type 2 Diabetes, wherein its expression was significantly higher than in healthy controls. Insulin receptor substrate 1 (IRS1) has been predicted to be a potential target of miR-144. Consistent with this observation, IRS1 mRNA and protein levels, verified by quantitative real-time PCR and western blotting respectively, were found to be down-regulated. Using luciferase assay, we further demonstrated that miR-144 directly targets IRS1 and showed its effects on protein expression via immunocytochemistry. From this cross-sectional study in humans, we have identified signature miRNAs which could explain the pathogenesis of T2D. Whether miRNAs like miR-144 could be potential therapeutic targets for management of T2D will need to be explored by further mechanistic and functional studies. miRNA profiling of tissues from T2D rat models. Total RNA (plus miRNAs) was isolated using a modification of the RiboPure™-Blood kit from Ambion (Austin,TX) according to the manufacturer’s protocol. The concentration of total RNA and integrity were determined by using Nano-Drop ND-1000 Spectrophotometry (NanoDrop Tech, Rockland, Del) and gel electrophoresis respectively.
Project description:Over 40 % of microRNAs are located in introns of coding genes, and many intronic microRNAs are co-regulated with their host genes. In such cases of co-regulation, the products of host genes and their intronic microRNAs can cooperate to coordinately regulate biologically important pathways. Therefore, we screened intronic microRNAs dysregulated in liver of obese mouse models to identify previously uncharacterized coding host genes that may contribute to the pathogenesis of obesity-associated insulin resistance and type 2 diabetes mellitus. Our approach identified that expression of both Ectodysplasin A (Eda), the causal gene of X-linked hypohidrotic ectodermal dysplasia (XLHED; MIM 305100) and its intronic microRNA, miR-676, was strongly increased in liver of obese mouse models. Moreover, hepatic EDA expression is increased in obese human subjects, reduced upon weight loss, and its hepatic expression correlates with systemic insulin resistance. Eda expression in murine liver is controlled via PPARg activation, increases in circulation and promotes JNK activation and inhibitory serine phosphorylation of IRS1 in skeletal muscle. Consistently, bi-directional modulation of hepatic Eda expression in mouse models affects systemic glucose metabolism with alterations of muscle insulin signaling, revealing a novel role of EDA as an obesity-associated hepatokine, which impairs insulin sensitivity in skeletal muscle.
Project description:Results Platelets in non-diabetic patients demonstrated miRNA expression profiles comparable to previously published data. The miRNA expression profiles of platelets in diabetics were similar. Statistical analysis unveiled only three miRNAs (miR-377-5p, miR-628-3p, miR-3137) with high reselection probabilities in resampling techniques, corresponding to signatures with only modest discriminatory performance. Functional annotation of predicted targets for these miRNAs pointed towards an influence of diabetes mellitus on mRNA processing. Conclusions/interpretation We did not find any major differences in platelet miRNA profiles between diabetics and non-diabetics. Minor differences pertained to miRNAs associated with mRNA processing. Thus, previously described differences in plasma miRNAs between diabetic and nondiabetic patients cannot be explained by plain changes in the platelet miRNA profile. Platelet miRNA profiles were assessed in clinically stable diabetic and nondiabetic patients (each n=30). Platelet miRNA was isolated from leucocyte-depleted platelet-rich plasma, and miRNA profiling was performed using LNA micro-array technology (miRBase 18.0, containing 1,917 human miRNAs). Effects of diabetes mellitus were explored by univariate statistical tests for each miRNA, adjusted for potential confounders, and by developing a multivariable signature, which was evaluated by resampling techniques. Platelet phenotype was assessed by light transmission aggregometry and impedance aggregometry.
Project description:microRNA profiling of mouse small intestinal crypt cells comparing control untreated with cells treated with insulin growth factor-1 (IGF-1). IGF-1 stimulated cell proliferation, as observed in Brdu incoporation assay. Two condition experiment. Control vs IGF-1 treatment. Biological replicates: 3 control, 3 treated. Independently grown and harvested. One replicate per array
Project description:We report the identification of microRNA-138 (miR-138), as a molecular signature of GSCs and demonstrate a vital role for miR-138 to promote growth and survival of bona fide tumor-initiating cells with self-renewal potential. Total RNA from Glioma Stem Cells and Neural Stem Cells were subjected to microRNA microarray analysis, 3 replicates each.
Project description:Using microarray, we compared the expression of miRNAs from the peripheral blood of male subjects with T1DM and T2DM with healthy controls. Healthy male controls used were age-matched to the T2DM group patients with mean(SD) 37.3 (7.1) years. Subjects with T1DM were younger [23.3(1.6) years]. Expression was compared and validated using quantitative real-time PCR. Statistical testing (ANOVA, P-value <0.05) was performed and fold changes with respect to the control were calculated Systolic BP, fasting glucose, HbA1c, total cholesterol and LDL-cholesterol levels were significantly higher in T2DM subjects compared with controls (P-value <0.05). Compared with controls, we identified 37 differentially regulated miRNAs in DM subjects. Among them, 21 miRNAs were upregulated (2-5 fold change, p-value < 0.05) and 16 miRNAs were downregulated (1.5-2 fold change, p-value < 0.05). These miRNAs had gene putative targets primarily involved in regulating pancreatic development and functions, adipocyte differentiation, insulin signaling and glucose-dependent insulin secretion. peripheral blood of male subjects with T1DM and T2DM with healthy controls
Project description:To evaluate whether serum micoRNAs can be biomarkers for diagnosis of type 1 diabetes mellitus, we analyzed the serum microRNA expression profiles in 6 patients with new-onset type 1 diabetes mellitus and 6 age- and gender-matched healthy controls. A difference was observed in 31 miRNAs between the patients and controls (fold change ≥ 2, P < 0.05) Overall design: 6 serum samples from patients with new-onset type 1 diabetes mellitus and 6 serum samples from age- and gender-matched healthy controls
Project description:microRNA profiling of rat small intestinal crypt cell IEC-6. Comparing control untreated with cells treated with transforming growth factor-beta (TGF-beta). TGF-beta stimulated cell differentiation, as observed in the stimulation of intestinal epithelial cell markers (alkaline phophotase, villin, aminopeptidase N, etc.). Two condition experiment. Control vs TGF-beta treatment. Biological replicates: 3 control, 3 treated. Independently grown and harvested. One replicate per array
Project description:Lack of change in microRNA expression in adult mouse liver following treatment with benzo(a)pyrene (BaP), as detected using Exiqon miRNA arrays. Adult male mice were exposed to 150 mg/kg benzo(a)pyrene (BaP) or solvent for 3 days and sampled 4 hours after the last dose. MicroRNA expression levels in adult mouse liver were measured using Exiqon miRNA arrays. Our results indicate a distinct lack of effect of BaP of miRNA expression, despite widespread changes in mRNA levels (measured using Agilent arrays). Lack of miRNA changes was confirmed with Agilent miRNA arrays. Keywords: Toxicology, miRNA Adult male B6C3F1 mice were exposed to a daily dose of corn oil (vehicle control group) or 150 mg/kg BaP (treatment group) for 3 d (n=6 per group). Mice were sacrificed at 4 h or 24 h following the last dose and liver lobes were extracted and flash frozen. Exiqon miRNA arrays were used to examine changes in miRNA transcript levels in random liver lobe sections.