涤痰益智汤通过PTEN/PI3K/AKT/mTOR信号通路抑制自噬改善血管性痴呆大鼠认知障碍的机制研究OA

Objective To observe the effects of Ditan Yizhi Decoction on PTEN/PI3K/AKT/mTOR signaling pathway and autophagy in rats with vascular dementia(VaD);To explore its mechanism in improving VaD cognitive impairment.Methods Totally 40 male SD rats were randomly divided into sham-operation group,model group,Ditan Yizhi Decoction+inhibitor group,Ditan Yizhi Decoction group and donepezil hydrochloride group,with 8 rats in each group.In the sham-operation group,only the common carotid artery was isolated without ligation,while in the other groups,the VaD model was established by modified permanent ligation of bilateral common carotid artery.Rats in each group received corresponding treatment for 4 weeks.Morris water maze test was used to detect the learning and memory ability of rats,HE staining and Nissl staining were used to observe the morphology of hippocampal neurons,the autophagy of neurons was observed by transmission electron microscope,and the contents of brain-derived neurotrophic factor(BDNF)and nerve growth factor(NGF)in serum were detected by ELISA,the protein expressions of PTEN,p-AKT,p-mTOR,p-PI3K,p62,Beclin-1 and LC3Ⅱ/Ⅰ were detected by Western blot and immunohistochemistry.Results Compared with the sham-operation group,the escape latency of the model group was prolonged and the number of crossing the platform was reduced(P<0.01);the gap of neurons in hippocampal CA1 area was enlarged,the morphology of cells was irregular,the boundary was fuzzy,neurons were pyknosis,Nissl bodies were dissolved and broken,and the number was reduced,transmission electron microscopy showed that the number of autophagosomes and autolysosomes in neurons increased;the contents of BDNF and NGF in serum significantly decreased(P<0.01);the protein expressions of PTEN,Beclin-1 and LC3Ⅱ/Ⅰ in hippocampal tissue significantly increased(P<0.01),while the protein expressions of p-AKT,p-mTOR,p-PI3K and p62 significantly decreased(P<0.01).Compared with the model group,the escape latency of Ditan Yizhi Decoction group was shortened and the number of crossing the platform increased(P<0.01);the number of neurons in hippocampal CA1 area increased,the morphology was normal,arranged orderly,Nissl bodies were abundant,and autophagosomes and autolysosomes were reduced by transmission electron microscopy;the contents of BDNF and NGF in serum significantly increased(P<0.01);the protein expressions of PTEN,Beclin-1 and LC3Ⅱ/Ⅰ in hippocampal tissue significantly decreased(P<0.01),while the protein expressions of p-AKT,p-mTOR,p-PI3K and p62 significantly increased(P<0.01).PI3K inhibitor could inhibit PI3K/Akt/mTOR signaling pathway and reverse the inhibitory effect of Ditan Yizhi Decoction on autophagy.Conclusion Ditan Yizhi Decoction can improve learning memory ability and neuronal morphology in VaD rats,and its mechanism may be related to the inhibition of autophagy by regulating PTEN/PI3K/AKT/mTOR signaling pathway.