MicroRNA 144 Impairs Insulin Signaling by Inhibiting the Expression of Insulin Receptor Substrate 1 in Type 2 Diabetes Mellitus

University of Barcelona, Spain
PLoS ONE (Impact Factor: 3.23). 08/2011; 6(8):e22839. DOI: 10.1371/journal.pone.0022839
Source: PubMed


Dysregulation of microRNA (miRNA) expression in various tissues and body fluids has been demonstrated to be associated with several diseases, including Type 2 Diabetes mellitus (T2D). Here, we compare miRNA expression profiles in different tissues (pancreas, liver, adipose and skeletal muscle) as well as in blood samples from T2D rat model and highlight the potential of circulating miRNAs as biomarkers of T2D. In parallel, we have examined the expression profiles of miRNAs in blood samples from Impaired Fasting Glucose (IFG) and T2D male patients.
Employing miRNA microarray and stem-loop real-time RT-PCR, we identify four novel miRNAs, miR-144, miR-146a, miR-150 and miR-182 in addition to four previously reported diabetes-related miRNAs, miR-192, miR-29a, miR-30d and miR-320a, as potential signature miRNAs that distinguished IFG and T2D. Of these microRNAs, miR-144 that promotes erythropoiesis has been found to be highly up-regulated. Increased circulating level of miR-144 has been found to correlate with down-regulation of its predicted target, insulin receptor substrate 1 (IRS1) at both mRNA and protein levels. We could also experimentally demonstrate that IRS1 is indeed the target of miR-144.
We demonstrate that peripheral blood microRNAs can be developed as unique biomarkers that are reflective and predictive of metabolic health and disorder. We have also identified signature miRNAs which could possibly explain the pathogenesis of T2D and the significance of miR-144 in insulin signaling.

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Available from: Subramaniam Tavintharan,
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    • "Generally, an increased level of cellular miR-146a that exerts a negative feedback effect on NF-κB signaling is observed during multiple stresses (e.g., TNF-α, LPS, interleukin- (IL-) 1β, PMA, and ox-LDL) [6, 8–11]. However, decreased cellular miR-146a levels have been reported in multiple diabetes-related studies, including in high glucose- (HG-) stimulated endothelial cells and diabetic rats [12, 13], in diabetic mouse wounds [14], in glycated albumin-stimulated endothelial cells [15], and in type 2 diabetes patients with subclinical inflammation and insulin resistance [16]. All of the above in vitro and in vivo evidences indicate that impaired miR-146a expression contributes to the proinflammatory state in diabetes. "
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    ABSTRACT: Diabetes is associated with hyperglycemia and increased thrombin production. However, it is unknown whether a combination of high glucose and thrombin can modulate the expression of NAPDH oxidase (Nox) subtypes in human aortic endothelial cells (HAECs). Moreover, we investigated the role of a diabetes-associated microRNA (miR-146a) in a diabetic atherothrombosis model. We showed that high glucose (HG) exerted a synergistic effect with thrombin to induce a 10.69-fold increase in Nox4 mRNA level in HAECs. Increased Nox4 mRNA expression was associated with increased Nox4 protein expression and ROS production. Inflammatory cytokine kit identified that the treatment increased IL-8 and IL-6 levels. Moreover, HG/thrombin treatment caused an 11.43-fold increase of THP-1 adhesion to HAECs. In silico analysis identified the homology between miR-146a and the 3'-untranslated region of the Nox4 mRNA, and a luciferase reporter assay confirmed that the miR-146a mimic bound to this Nox4 regulatory region. Additionally, miR-146a expression was decreased to 58% of that in the control, indicating impaired feedback restraint of HG/thrombin-induced endothelial inflammation. In contrast, miR-146a mimic transfection attenuated HG/thrombin-induced upregulation of Nox4 expression, ROS generation, and inflammatory phenotypes. In conclusion, miR-146a is involved in the regulation of endothelial inflammation via modulation of Nox4 expression in a diabetic atherothrombosis model.
    Mediators of Inflammation 09/2014; 2014:379537. DOI:10.1155/2014/379537 · 3.24 Impact Factor
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    • "These results suggest that a change in the level of these c-miRNAs may be useful as a biomarker for the clinical diagnosis of rhabdomyosarcoma in the future, for which there is no serum biomarker currently known. Furthermore, Karolina et al. (2011) found that the level of circulating miR-144 increased in type 2 diabetic animals and humans and that this elevation is negatively correlated with insulin receptor substrate 1 in insulin-responding tissues, including skeletal muscle. Thus, the elevation of miR-144 in circulation may be associated with the development of insulin resistance in skeletal muscle. "
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    ABSTRACT: MicroRNAs (miRNAs) are small non-coding RNAs involved in post-transcriptional gene regulation. Recently, growing evidence has shown that miRNAs are taken in by intracellular exosomes, secreted into circulation, and taken up by other cells. Circulating levels of several miRNAs are changed in diseases such as cancer, diabetes, and cardiovascular diseases; therefore, they are suggested to regulate functions of the recipient cells by modulating protein expression. Circulating miRNAs (c-miRNAs) may also modulate skeletal muscle function in physiological and pathological conditions. It has been suggested that acute and chronic exercise transiently or adaptively changes the level of c-miRNAs, thus post-transcriptionally regulating proteins associated with energy metabolism, myogenesis, and angiogenesis. Circulating levels of several miRNAs that are enriched in muscle are altered in muscle disorders and may be involved in their development and progression. In addition, such c-miRNAs may be useful as biomarkers to determine various interactions between tissues and also to reflect athletic performance, physical fatigue, incidence risk, and development of diseases.
    Frontiers in Physiology 02/2014; 5:39. DOI:10.3389/fphys.2014.00039 · 3.53 Impact Factor
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    • "Emerging studies indicate that miRNAs are important regulators in a variety of developmental, physiological and pathological processes including cell proliferation, migration, differentiation, apoptosis, inflammation and stem cell maintenance [5-10]. In addition, there is substantial evidence supporting the involvement of miRNAs in many diseases including cancer [11-13], cardiovascular disorders [14,15], and diabetes [16-19], which may have an impact on future treatments of such diseases. "
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    ABSTRACT: MicroRNAs are powerful gene expression regulators, but their corneal repertoire and potential changes in corneal diseases remain unknown. Our purpose was to identify miRNAs altered in the human diabetic cornea by microarray analysis, and to examine their effects on wound healing in cultured telomerase-immortalized human corneal epithelial cells (HCEC) in vitro. Total RNA was extracted from age-matched human autopsy normal (n=6) and diabetic (n=6) central corneas, Flash Tag end-labeled, and hybridized to Affymetrix® GeneChip® miRNA Arrays. Select miRNAs associated with diabetic cornea were validated by quantitative RT-PCR (Q-PCR) and by in situ hybridization (ISH) in independent samples. HCEC were transfected with human pre-miR(TM)miRNA precursors (h-miR) or their inhibitors (antagomirs) using Lipofectamine 2000. Confluent transfected cultures were scratch-wounded with P200 pipette tip. Wound closure was monitored by digital photography. Expression of signaling proteins was detected by immunostaining and Western blot. Using microarrays, 29 miRNAs were identified as differentially expressed in diabetic samples. Two miRNA candidates showing the highest fold increased in expression in the diabetic cornea were confirmed by Q-PCR and further characterized. HCEC transfection with h-miR-146a or h-miR-424 significantly retarded wound closure, but their respective antagomirs significantly enhanced wound healing vs. controls. Cells treated with h-miR-146a or h-miR-424 had decreased p-p38 and p-EGFR staining, but these increased over control levels close to the wound edge upon antagomir treatment. In conclusion, several miRNAs with increased expression in human diabetic central corneas were found. Two such miRNAs inhibited cultured corneal epithelial cell wound healing. Dysregulation of miRNA expression in human diabetic cornea may be an important mediator of abnormal wound healing.
    PLoS ONE 12/2013; 8(12):e84425. DOI:10.1371/journal.pone.0084425 · 3.23 Impact Factor
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