LncRNA SNHG12 inhibits miR-199a to upregulate SIRT1 to attenuate cerebral ischemia/reperfusion injury through activating AMPK signaling pathway

Cerebral ischemia caused severe disability, and associated with a series of neurological events. Long non-coding RNA SNHG12 was found to be upregulated in mouse brain microvascular endothelial cells by cerebral ischemia. Moreover, it was reported that SNHG12 could directly interact with miR-199a and sirtuin 1 (SIRT1) as a direct target of miR-199a in other diseases. However, the function and mechanism of SNHG12 in cerebral ischemia and reperfusion (I/R) injury of neuronal cells remains unclear. The present study was thus designed to explore the potential effect of SNHG12 and to investigate the underlying mechanism in I/R neuronal cells. we found that SNHG12 was upregulated in primary neuronal cells and N2a cells and peaked at 12 h and 24 h after OGD/R treatment, respectively. Meanwhile, MTT assay showed that knockdown SNHG12 inhibited cell proliferation under OGD/R condition. And flow cytometry analyses revealed more apoptosis rate was caused by SNHG12 knockdown. Mechanistically, SNHG12 interacted with miR-199a and decreased the expression of miR-199a. Overexpression miR-199a largely inhibited the cell proliferation and induced the cell apoptosis. Meanwhile, SNHG12 was proven to target miR-199a and then activated SIRT1 expression, which finally led to activation of AMPK signaling pathway. In summary, we demonstrate SNHG12 targets miR-199a to upregulate SIRT1 expression, which attenuates cerebral ischemia/reperfusion injury through AMPK pathway activation. Our findings provide molecular mechanism by which SNHG12 attenuates cerebral I/R injury and facilitate development of therapeautical strategies for treating ischemia-induced stroke.