[Buyang Huanwu Decoction attenuates cerebral ischemia-reperfusion injury in rats via miR-26a-5p mediated PTEN/PI3K/Akt signaling pathway].

Abstract

This study aims to investigate the mechanism of Buyang Huanwu Decoction in treatment of cerebral ischemia-reperfusion injury in rats. A total of 180 SD rats were randomly divided into 5 different groups: sham group, model group, Buyang Huanwu Decoction group, Buyang Huanwu Decoction + miR-26a-5p agomir(agomir) group, Buyang Huanwu Decoction + miR-26a-5p agomir negative control(agomir NC) group. There were 36 rats in each group. Each group was then subdivided into three subgroups for the duration of reperfusion(3, 7, 14 d). A ligature-induced middle cerebral artery occlusion(MCAO) model was carried out on all groups other than sham group. Reperfusion was performed following ischemia for 90 min. Buyang Huanwu Decoction group, agomir group, and agomir NC group were given Buyang Huanwu Decoction twice daily by gavage 24 h after the formation of the model. Sham group and model group were given an equal amount of physiological saline by gavage until the day before sacrifice. At 24 h after ischemia induction, miR-26a-5p agomir was injected into the lateral ventricle in agomir group, miR-26a-5p NC in agomir NC group, and equal amounts of physiological saline in the other groups. 24 h after ischemia induction, BrdU was intraperitoneally injected once daily until the day before sacrifice. Modified neurological severity score(mNSS) was used to evaluate neurological deficits, 2,3,5-triphenyltetrazolium chloride(TTC) staining was used to determine the cerebral infarct volume, TUNEL staining was used to assess the apoptosis of parenchymal ischemic brain tissue, and double immunofluorescence staining was used to examine BrdU/NeuN double positive neurons in the parenchymal ischemic brain tissue to evaluate the neuronal regeneration. We employed a luciferase reporter assay to identify and validate that the target gene of miR-26a-5p is PTEN. Real-time quantitative polymerase chain reaction(RT-qPCR) was used to assess gene expression levels of PTEN and miR-26a-5p and Western blot to assess the protein levels of PTEN, PI3K, p-PI3K, Akt, and p-Akt. The results revealed that compared with model group, Buyang Huanwu Decoction treatment promoted neural function recovery, reduced the cerebral infarct volume, increased the number of BrdU~+/NeuN~+ neurons, upregulated the expression of miR-26a-5p, regulated the PTEN/PI3K/Akt signaling pathway, and promoted neuronal regeneration in the cerebral ischemia-reperfusion rats. These effects were significantly enhanced after lateral ventricle injection of miR-26a-5p agomir. The findings prove that Buyang Huanwu Decoction treatment can promote neural function recovery, reduce the cerebral infarct volume, and promote neuronal regeneration in a cerebral ischemia-reperfusion rat model, which is likely to be achieved via miR-26a-5p mediated PTEN/PI3K/Akt signaling pathway.