The Regulatory Mechanism Of Tanshinone ?A On Neuroprotection After Cerebral Infarction Based On PI3K/Akt/mT0R Tor Signaling Pathway

Background Cerebral infarction is the most common disease in the cerebral vascular disease and leading reason that cause disability,in addition to the earlier thrombolysis,the disease is still lack of effective treatment.Now the treatment of cerebral infarction mainly divided into two: reperfusion and neural protection.The window of therapy time for thrombolytic is only 3-4.5 h,however,thrombolytic could cause intracranial bleeding so that the application of thrombolytic in clinical is limited.Hence,the best treatment is combination "reperfusion" with "neuroprotection" as soon as possible when cerebral infarction happen.There are studies have shown that excessive autophagy activation after cerebral infarction can result in cell death,but the excessive autophagy activation mechanism is still unclear,remains to be elucidated.PI3K/Akt/m TOR signaling pathways that could regulate cell proliferation,survival,growth,differentiation,and it is the upstream pathways of regulation of autophagy.The previous studies found that PI3K/Akt signal channel with inhibition which is the upstream pathway of autophagy after cerebral infarction,and tanshinone IIA can activate the PI3K/Akt,but whether tanshinone IIA can inhibit its downstream autophagy still needs further research.The research that based on PI3K/Akt/m TOR signaling pathway to explore cerebral infarction after the excessive autophagy activation mechanism and tanshinone IIA regulatory mechanism of autophagy after cerebral infarction could provide experimental basis for clinical treatment of cerebral infarction and provide a new way for prevention and treatment of cerebral infarction of traditional Chinese medicine.Objective To explore the excessive autophagy activation mechanism after cerebral infarction and the regulatory mechanism of autophagy by tanshinone IIA after cerebral infarction based on PI3K/Akt/m TOR signaling pathway.Methods First of all to the cultivation of rat hippocampal cell lines,and then build a OGD model of rat hippocampal neurons.To observe cell proliferation after ordinary cultivation with lack of oxygen and sugar,the effect on cell proliferation after cerebral infarction.Using different concentrations of tanshinone IIA processing OGD nerve cells in the OGD model to study the neural cell protection of tanshinone IIA(Including cell proliferation,oxidative damage,mitochondrial membrane permeability,autophagy).To use different concentrations of tanshinone IIA processing OGD cells to study the nerve protective effect based on PI3K/Akt/m TOR pathway.Results 1.After compared with the common cultivation,OGD6 / R6 model is more than 50% cell death,but tanshinone IIA processing has significant inhibition of cell death,it shows that tanshinone IIA play a role in cell protection.2:(1)Tanshinone IIA can piay the nerve protective effect by promoting nerve cells proliferation.(2)Using CM-H2 DCFDA tag process of oxidative stress in cells(green fluorescence)show that tanshinone IIA can inhibit cellular ros so that play a neuroprotective effect.(3)The reactive oxygen species produced damage mitochondrial membrane and affect the change of membrane potential,with JC-1 mark membrane potential changes(resting potentials for red,green for the action potential)showed that tanshinone IIA can inhibit the mitochondrial membrane potential so that play a role in nerve protection.(4)Tanshinone IIA can effectively reduce the generation of autophagy protein LC3 II,tanshinone IIA by increasing the upstream P85,Akt,m TOR to inhibit autophagy protein expression to play nerve protective effect.3:(1)Tanshinone IIA can piay the nerve protective effect by promoting nerve cells proliferation.,however,by the use of m TOR si RNAs,Akt si RNAs,LY294002(PI3K inhibitors)treatment after HT-22 nerve cells,tanshinone IIA showed no related nerve protective effect.(2)Tanshinone IIA can inhibit the reactive oxygen species so that play a nerve protection,but the use of m TOR si RNAs,Akt si RNAs,LY294002(PI3K inhibitors)treatment after HT-22 nerve cells,tanshinone IIA showed no related nerve protective effect.(3)Tanshinone IIA can stabilize the mitochondrial membrane potential steady nerve protective effect,but the use of m TOR si RNAs,Akt si RNAs,LY294002(PI3K inhibitors)treatment after HT-22 nerve cells,tanshinone IIA showed no related nerve protective effect.(4)Tanshinone IIA can effectively reduce the generation of autophagy protein LC3 II,but using m TOR si RNAs,Akt si RNAs,LY294002(PI3K inhibitors)treatment after HT-22 nerve cells,the expression of tanshinone IIA no reduce LC3II;Tanshinone IIA can activate pp85,p-akt and p-m TOR,reduce the expression of LC3 II nerve protective effect into full play.Conclusion At the cellular level,tanshinone IIA could play a role of neuroprotection by activating upstream part in PI3K/Akt/m TOR signaling pathways,and thus inhibit its downstream autophagy.