Resveratrol Attenuates A?_25-35 Induced Neurotoxicity By Inducing Autophagy Via TyrRS-PARP-SIRT1 Signaling Pathway

Alzheimer's disease?AD?is a hidden onset and progressive development neurodegenerative disorder,which has become one of the top high mobility diseases among the elderly over 65.It is a serious threat to the health of elderly;however,its complicated pathogenesis remains unknown.Currently,?-amyloid?A??caused neurotoxicity thought to be critical for inducing and promoting AD,and has been recognized as the potential therapeutic target for AD prevention and treatment.Nevertheless,there's still absent of effective strategies.In recent years,several research groups with expertise in nutritional and botanical science pointed out that phytochemicals exert excellent protective effect on various chronic diseases such as cardiovascular disease,diabetes and AD,meanwhile,due to its non-toxic property;phytochemicals has become the research hotspot worldwide in the treatment of chronic diseases and related underlying mechanisms.Resveratrol?RSV?is a natural polyphenol,large amount of epidemiological investigations and experimental researches indicated that RSV could significantly attenuate AD and effectively prevent its onset and development.Further study showed that RSV alleviates AD through attenuating A?-induced toxicity in neurons;however,the specific mechanism is unclear yet.Autophagy,widely existing in eukaryotic cells,is a cellular pathway refers to the degradation of proteins and organelles.Recent research found that autopahgy displayed an important role in the onset and development of AD;moreover,it has been demonstrated that RSV ameliorated hepatic steatosis and attenuated endothelial inflammation via autophagy induction.However,whether RSV attenuates A?-induced toxicity by inducing autophagy and its potential mechanisms are to be further interpreted.In addition,new discovery reported that tyrosyl transfer-RNA?tRNA?synthetase?Tyr RS?is the biological target of RSV.RSV can directly bind to the active site of Tyr RS,thereafter,triggering TyrRS-PARP1 signaling pathway and ultimately activating the expression of stress reaction protectivemolecules such as SIRT1 ? AMPK,which exert biological protective effect on health.Accordingly,based on current scientific evidences,we bring out hypothesis as follows:RSV may induce autophagy in response to A?-caused neurotoxicity via the TyrRS-PARP1-SIRT1 signaling pathway and finally attenuate AD.To confirm this hypothesis,we used PC12 cells treated with ?-amyloid protein fragment 25-35(A?_25-35)to establish the neuron injured model,then added various inhibitors or siRNA to examine RSV's effect on autophagy,besides,we further determined the role of TyrRS-PARP1-SIRT1 signaling pathway in RSV-induced autophagy.Transmission electron microscope?TEM?and western blot techniques were also applied to explore the mechanisms in A?_25-35-caused neurotoxicity which is alleviated by RSV.Major experiment results and conclusions are as follows:?1?RSV obviously attenuates A?_25-35-induced neurotoxicity.PC12 cells was treated with A?_25-35 to built the neuron injured model,CCK-8 assay was used to tested the cell viability and microscope to observe the cell morphology,comprehensive results indicated that RSV could attenuate the cell morphology and neurons' death.While reaching 20 ?M,RSV restored the injured cells similar to the control group.?2?RSV attenuates A?_25-35-caused neurotoxicity via autophagy induction.Determined by western blot and TEM,we found that RSV notably up-regulated LC3-II expression,promoted p62 degradation and autophagosome formation.Nevertheless,pretreatment of 3-MA remarkably weaken RSV's protection role in A?_25-35-induced neurotoxicity.Results above showed that RSV protected neurons through inducing autophagy.?3?TyrRS-PARP1-SIRT1 signaling pathway is critical for RSV-induced autophagy.Experiment data revealed that RSV notably promoted the expression of TyrRS?PARP1 and SIRT1 in a dose-dependent manner;and RSV-induced autophagy was significantly suppressed in the presence of TyrRS and SIRT1 siRNA?inhibitors of PARP1?NAMPT and SIRT1,suggesting the vital role of Tyr RS-PARP1-SIRT1 signaling pathway in RSV-induced autophagy.All in all,RSV induces autophagy via activating Tyr RS-PARP1-SIRT1 signaling pathway,thus protects neurons against A?_25-35-induced neurotoxicity,and therefore realizes its health protective effect on AD.Our research has provided important experimentevidences to deep understand the mechanisms of RSV attenuating AD,moreover,it is of great significance to further develop a more safe and effective medicine of AD prevention.