MicroRNA-103-1 Selectively Downregulates Brain NCX1 and Its Inhibition by Anti-miRNA Ameliorates Stroke Damage and Neurological Deficits

Abstract

Na(+)/Ca2+ exchanger (NCX) is a plasma membrane transporter that, by regulating Ca2+ and Na(+) homeostasis, contributes to brain stroke damage. The objectives of this study were to investigate whether there might be miRNAs in the brain able to regulate NCX1 expression and, thereafter, to set up a valid therapeutic strategy able to reduce stroke-induced brain damage by regulating NCX1 expression. Thus, we tested whether miR-103-1, a microRNA belonging to the miR-103/107 family that on the basis of sequence analysis might be a potential NCX1 regulator, could control NCX1 expression. The role of miR-103-1 was assessed in a rat model of transient cerebral ischemia by evaluating the effect of the correspondent antimiRNA on both brain infarct volume and neurological deficits. NCX1 expression was dramatically reduced when cortical neurons were exposed to miR-103-1. This alleged tight regulation of NCX1 by miR-103-1 was further corroborated by luciferase assay. Notably, antimiR-103-1 prevented NCX1 protein downregulation induced by the increase in miR-103-1 after brain ischemia, thereby reducing brain damage and neurological deficits. Overall, the identification of a microRNA able to selectively regulate NCX1 in the brain clarifies a new important molecular mechanism of NCX1 regulation in the brain and offers the opportunity to develop a new therapeutic strategy for stroke.

Mir363-3p improves ischemic stroke outcomes in female but not male rats

“…Occluding the middle cerebral artery (MCAo) to the mir-223 knock out mouse increases infarct volume as compared to the wildtype control, and rAAV-mediated transfer of miR-223 reduces infarct volume (Harraz et al, 2012). Similarly, antagomirs to Let7f infused after stroke (Selvamani et al, 2012), mir181a infused before stroke (Moon et al, 2013), and mir103-1 delivered before or after stroke (Vinciguerra et al, 2014) also decreased infarct volume. A recent study also shows that the route of miRNA administration may also affect outcomes, such that intravenous but not intracerebroventricular, mir122 improved stroke outcome in adult rats (Liu da et al, 2016).…”

p38/Sp1/Sp4/HDAC4/BDNF Axis Is a Novel Molecular Pathway of the Neurotoxic Effect of the Methylmercury

“…SH-SY5Y cells were incubated in a low serum medium (Guida et al, 2015b) and treated with MeHg 1 μM at 12 and 24 h. For dose-dependent experiments, primary cortical neurons were treated for 24 h with MeHg at 0.1, 0.5, 1, and 3 μM. For SB239063 experiments cells were pre-treated for 2 h with the drug at 10 μM followed with MeHg 1 μM for 24 h. All transfection experiments in SH-SY5Y and cortical neurons were performed 24 h before MeHg treatment (1 μM/24 h) with HiPerFect Transfection Reagent (Quiagen) in accordance with the manufacture's protocol, as previously reported (Vinciguerra et al, 2014). In SH-SY5Y cells and cortical neurons the synthetic small interfering RNA (siRNA) transfections for Sp1 (siSp1), HDAC4 (siHDAC4), and negative control (siCTL) were performed as already reported (Formisano et al, 2015b; Guida et al, 2016).…”

Peripheral biomarkers of stroke: Focus on circulatory microRNAs

“…AntimiR-103-1 prevented NCX1 protein down regulation induced by the increase in miR 103-1 after brain ischemia, thereby reducing brain damage and neurological deficits. Further they concluded that blocking mir-103-1 by microRNA inhibitors was a reasonable strategy to stop neuro detrimental regulation of NCX occurring during ischemic conditions [40]. …”