LncRNA AC136007.2 alleviates cerebral ischemic-reperfusion injury by suppressing autophagy

Differential expression and diagnostic significance of the long noncoding RNA (lncRNA) AC136007.2 has been reported in patients with acute ischemic stroke (AIS). However, its role on disease progression and outcome remains unclear. Here, we employed an oxygen-glucose deprivation/reperfusion (OGD/R) model in neuronal SH-SY5Y cells and performed middle cerebral artery occlusion (MCAO) surgery in rats to investigate the function of AC136007.2 in ischemia-reperfusion (I/R) injury. AC136007.2 expression was determined by RT-qPCR and cell viability was examined using CCK-8, Edu, LDH, and apoptosis assays. Pro-inflammatory cytokine expression was assessed using ELISA. OGD/R downregulated AC136007.2 expression in SH-SY5Y cells, decreased viability by inducing apoptosis, and stimulated secretion of TNF-α, IL-6, and IL-1β. In turn, lentivirus-mediated AC136007.2 overexpression significantly reversed these phenomena. LC3 immunofluorescence and western blotting analyses of LC3-I/II and Beclin-1 expression and AMPK/mTOR phosphorylation status showed that AC136007.2 suppressed autophagy in SH-SY5Y cells via inactivation of AMPK/mTOR signaling. Notably, incubation with the AMPK activator AICAR abolished the pro-survival effect of AC136007.2 upon OGD/R treatment. Importantly, intraventricular injection of AC136007.2 significantly reduced cerebral infarction and brain edema in MCAO rats, as shown by TTC staining and water content measurements. We conclude that AC136007.2 alleviates cerebral I/R injury by suppressing AMPK/mTOR-dependent autophagy.