Two single nucleotide polymorphisms in IL13 and IL13RA1 from individuals with idiopathic Parkinson's disease increase cellular susceptibility to oxidative stress.

The human genes for interleukin 13 (IL-13) and its receptor alpha 1 (IL-13Rα1) are in chromosomal regions associated with Parkinson's disease (PD). The interaction of IL-13 with its receptor increases the susceptibility of mouse dopaminergic neurons to oxidative stress. We identified two rare single SNPs in IL13 and IL13RA1 and measured their cytotoxic effects. rs148077750 is a missense leucine to proline substitution in IL13. It was found in individuals with early onset PD and no other known monogenic forms of the disease and is significantly linked with PD (Fisher's exact test: p-value = 0.01, odds ratio = 14.2). rs145868092 is a leucine to phenylalanine substitution in IL13RA1 affecting a residue critical for IL-13 binding. Both mutations increased the cytotoxic activity of IL-13 on human SH-SY5Y neurons exposed to sublethal doses of hydrogen peroxide, t-butyl hydroperoxide or RLS3, an inducer of ferroptosis. Our data show that both rs148077750 and rs145868092 conferred a gain-of-function that may increase the risk of developing PD.

Circulating MiR-19b-3p, MiR-134-5p and MiR-186-5p are Promising Novel Biomarkers for Early Diagnosis of Acute Myocardial Infarction.

BACKGROUND/AIMS: Recent studies have shown that circulating microRNAs (miRNAs) are emerging as promising biomarkers for cardiovascular diseases. This study aimed to determine whether miR-19b-3p, miR-134-5p and miR-186-5p can be used as novel indicators for acute myocardial infarction (AMI). METHODS: To investigate the kinetic expression of the three selected miRNAs, we enrolled 18 patients with AMI and 20 matched controls. Plasma samples were collected from each participant, and total RNA was extracted. Quantitative real-time PCR and ELISA assays were used to investigate the expression of circulating miRNAs and cardiac troponin I (cTnI), respectively. Plasma samples from another age- and gender-matched cohort were collected to investigate the impact of medications for AMI on the expression of the selected miRNAs. RESULTS: Levels of plasma miR-19b-3p, miR-134-5p and miR-186-5p were significantly increased in early stage of AMI. Plasma miR-19b-3p and miR-134-5p levels reached peak expression immediately after admission (T0), whereas miR-186-5p achieved peak expression at 4 h after T0. All of these times were earlier than the peak for cTnI (8 h after T0). In addition, all three miRNAs were positively correlated with cTnI. Receiver Operating Characteristic (ROC) analysis indicated that each single miRNA showed considerable diagnostic efficiency for predicting AMI. Furthermore, combining all three miRNAs in a panel increased the efficiency of distinguishing between patients with AMI and controls. Moreover, we found that heparin and medications for AMI did not impact the expression of these circulating miRNAs. CONCLUSION: Circulating miR-19b-3p, miR-134-5p and miR-186-5p could be considered promising novel diagnostic biomarkers for the early phase of AMI.

MicroRNA-101 protects cardiac fibroblasts from hypoxia-induced apoptosis via inhibition of the TGF-ß signaling pathway.

Cardiac fibroblasts (CFs) are the most numerous cells in the heart and are recognized primarily for their ability to maintain both the structural integrity and the physiological functions of the heart. The transforming growth factor beta (TGF-ß) signaling pathway is reportedly involved in the modulation of CF functions, including apoptosis. Recent studies have indicated that microRNA-101 (miR-101) attenuates the TGF-ß signaling pathway, either by inhibiting the expression of TGFß1 or by targeting transforming growth factor-ß receptor type I (TGFßRI). The present study aimed to determine whether miR-101 protects CFs from hypoxia-induced apoptosis and to investigate the mechanisms underlying its protective effects. The CCK-8 test, electron microscopy and TUNEL assay results demonstrated that miR-101a/b significantly inhibited hypoxia-induced CF apoptosis. The results of Western blotting, quantitative RT-PCR and immunofluorescence assays indicated that miR-101a dramatically inhibited the hypoxia-induced up-regulation of both TGFßRI and p-Smad 3 but not TGFß1 in CFs. Additionally, miR-101a significantly reversed the hypoxia-induced up-regulation of Bax and Caspase-3, the down-regulation of Bcl-2 and the activation of Caspase-3 in CFs. Moreover, miR-101a markedly inhibited the intracellular Ca(2+) ([Ca(2+)]i) overload caused by hypoxia. Taken together, our results suggest that miR-101a protects CFs against hypoxia-induced apoptosis by inhibiting the TGF-ß signaling pathway, which may be a potential therapeutic target for heart injury.

MicroRNA-101a inhibits cardiac fibrosis induced by hypoxia via targeting TGFßRI on cardiac fibroblasts.

BACKGROUND/AIMS: Hypoxia is a basic pathological challenge that is associated with numerous cardiovascular disorders including aberrant cardiac remodeling. Transforming growth factor beta (TGF-ß) signaling pathway plays a pivotal role in mediating cardiac fibroblast (CF) function and cardiac fibrosis. Recent data suggested that microRNA-101a (miR-101a) exerted anti-fibrotic effects in post-infarct cardiac remodeling and improved cardiac function. This study aimed to investigate the potential relationship between hypoxia, miR-101a and TGF-ß signaling pathway in CFs. METHODS AND RESULTS: Two weeks following coronary artery occlusion in rats, the expression levels of both TGFß1 and TGFßRI were increased, but the expression of miR-101a was decreased at the site of the infarct and along its border. Cultured rat neonatal CFs treated with hypoxia were characterized by the up-regulation of TGFß1 and TGFßRI and the down-regulation of miR-101a. Delivery of miR-101a mimics significantly suppressed the expression of TGFßRI and p-Smad 3, CF differentiation and collagen content of CFs. These anti-fibrotic effects were abrogated by co-transfection with AMO-miR-101a, an antisense inhibitor of miR-101a. The repression of TGFßRI, a target of miR-101a, was validated by luciferase reporter assays targeting the 3'UTR of TGFßRI. Additionally, we found that overexpression of miR-101a reversed the improved migration ability of CFs and further reduced CF proliferation caused by hypoxia. CONCLUSION: Our study illustrates that miR-101a exerts anti-fibrotic effects by targeting TGFßRI, suggesting that miR-101a plays a multi-faceted role in modulating TGF-ß signaling pathway and cardiac fibrosis.