Long non-coding RNA HCG11 silencing protects against cerebral ischemia/reperfusion injury through microRNA miR-381-3p to regulate tumour protein p53

Introduction
Long non-coding RNA (LncRNA) plays a critical role in cerebral ischemia-reperfusion (CI/R) injury. The purpose of the current research was to investigate the regulatory role of the LncRNA human leukocyte antigen complex group 11 (HCG11) in CI/R injury and explore its potential mechanism.

Material and methods
The rat middle cerebral artery occlusion (MCAO) model was established to simulate CI/R injury in vivo. mRNA levels of HCG11, microRNA (miR)-381-3p, tumour protein p53, and neuro-inflammatory factors were detected by quantitative reverse transcription PCR (RT-qPCR). Bederson score and Longa score were assessed for neurological deficits. Triphenyl tetrazolium chloride (TTC) staining was used to examine the cerebral infarct volume. What is more, oxidative stress was evaluated by the commercial kit. Finally, the relationship between HCG11, miR-381-3p, and p53 was verified by a dual-luciferase reporter assay.

Results
HCG11 was elevated in MCAO rats. And it competitively bound miR-381-3p and down-regulated the expression of p53. Inhibition of HCG11 inhibited cerebral infarct volume and neurological deficits in MCAO rats, and inhibited the secretion of neuro-inflammation and the over-activation of oxidative stress, exerting the protective effect of CI/R injury. However, inhibition of miR-381-3p in rats significantly weakened the protective effect of depression of HCG11 in MCAO rats, resulting in increased cerebral infarction volume and neurological deficits, elevated neuro-inflammatory secretion, and oxidative stress activation.

Conclusions
The present research shows that LncRNA HCG11 silencing protects against cerebral ischemia/reperfusion injury through miR-381-3p to regulate p53.