LncRNA SNHG6 functions as a ceRNA to regulate neuronal cell apoptosis by modulating miR-181c-5p/BIM signalling in ischaemic stroke.

Xi'An Zhang,Jinning Song,Shanqi Yuan,Zhanhui Liu,Zhiguo Xing,Qing Shu

doi:10.1111/jcmm.14480

Abstract

Long non‐coding RNAs (lncRNAs) play important roles in the pathogenesis of brain and neurodegenerative disorders. As far as we know, the functions and potential mechanisms of small nucleolar RNA host gene 6 (SNHG6) in ischaemic stroke have not been explored. This study aimed to examine the functional role of SNHG6 in the ischaemic stroke. Middle cerebral artery occlusion (MCAO) in mice and the oxygen glucose deprivation (OGD)‐induced injury in neuronal cells were applied to mimic ischaemic stroke. TTC staining, quantitative real‐time PCR, cell apoptosis assay, caspase‐3 activity assay, Western blot, RNA immunoprecipitation and luciferase reporter assay were performed to evaluate the function and possible mechanisms of SNHG6 in the pathogenesis of ischaemic stroke. The results show that SNHG6 expression was significantly increased both OGD‐induced neuronal cells and MCAO model mice. In vitro results showed that inhibition of SNHG6 increased cell viability, inhibited cell apoptosis and caspase‐3 activity in OGD‐induced neuronal cells. Consistently, knockdown of SNHG6 reduced brain infarct size and improved neurological scores in the MCAO mice. Mechanistic study further revealed that SNHG6 functioned as a competing endogenous RNA (ceRNA) for miR‐181c‐5p, which in turn repressed its downstream target of Bcl‐2 interacting mediator of cell death (BIM) and inhibiting cell apoptosis. This study revealed a novel function of SNHG6 in the modulating neuronal apoptosis in the ischaemic stroke model, and the role of SNHG6 in the regulating of neuronal apoptosis was at least partly via targeting miR‐181c‐5p/BIM signalling pathway.

Highlights

Stroke is the second most common cause of death and major cause of disability worldwide
We explored the role of small nucleolar RNA host gene 6 (SNHG6) in ischaemic stroke both in vitro and in vivo
Expression of SNHG6 significantly increased at different time points after Middle cerebral artery occlusion (MCAO) in the mice and after oxygen glucose deprivation (OGD) treatment in the cortical neurons

Summary

| INTRODUCTION

LncRNAs are found to exhibit differential functions in various human diseases, such as ischaemic stroke, hepatocellular carcinoma and breast can‐ cer, and demonstrate the ability to affect cell transformation, me‐ tastasis and apoptosis.[7,8,9] Previous study has revealed that SNHG6 promoted oesophageal squamous cell carcinoma cell proliferation and inhibited cell apoptosis.[10] the functions and biological mechanisms of SNHG6 in the neuronal cells under ischaemic stroke condition have not yet been explored. LncRNAs may functionally interact with a broad range of mi‐ croRNA (miRNA) molecules through competitively binding with miRNAs, which results in miRNA degradation. This interaction have been discovered in various biological processes of human diseases such as ischaemic stroke and neurodegenerative diseases.[11,12]. The in vitro functional assays were performed to elucidate the underly‐ ing molecular mechanisms of SNHG6 in the pathogenesis of isch‐ aemic stroke

| MATERIALS AND METHODS

Findings

| DISCUSSION