Panax Quinquefolium Saponins Regulate Endoplasmic Reticulum Stress And Inflammatory Pathway To Improve Functional Recovery After Spinal Cord Injury In Rats

Part Ⅰ Panax quinquefolium saponin repair neuronal function via regulation of endoplasmic reticulum stressObjective:Spinal cord injury(SCI)is one of the most serious complications of spinal injury.So far,there is no direct and effective treatment.Among them,promoting the regeneration and recovery of axons and losing the neurological function after spinal cord injury are the two best therapeutic options at present.Endoplasmic reticulum stress can occur in many neurodegenerative diseases.Regulation can protect neurons and promote their functional recovery.However,the specific role of endoplasmic reticulum in the direct role of acute traumatic spinal cord injury(SCI)is unknown.American ginseng saponin(PQS)is the main active ingredient of Panax quinquefolium.It has anti-inflammatory and anti apoptotic effects in many diseases.However,the potential impact of PQS on the pathophysiological process of acute traumatic SCI is not yet clear.The present study is to explore the protective and protective effects of PQS on damaged spinal cord from the point of endoplasmic reticulum stress,and further demonstrate the effect of anti endoplasmic reticulum stress to improve cell apoptosis and promote axonal repair.Through this study,we will be more aware of the role of PQS in spinal cord injury and the production of its mechanisms and provide a meaningful basis for the treatment of spinal cord injury and provide a new treatment for spinal cord injury in the future.Methods:It can be divided into two directions:animal experiment and cell experiment.In vitro experiment:the healthy female Sprague-Dawley rats were randomly divided into 3 groups:Sham group,SCI group and SCI+PQS group.HE staining and Nissl staining were used to evaluate the destruction of tissue structure of the spinal cord at 28 days after operation.The BBB scores and inclined plane test scores were used to evaluate the functional recovery at 1,3,5,5,7,14,21,28 day in the rats after acute injury.In order to verify whether PQS can inhibit the apoptosis,we use Western blot to detect the expression of Cleaved-caspase3,Bax and Bcl-2.Western blot is also used to detect the expression of acetyl-a-tubulin.TUNEL method was used to detect the number of apoptotic cells in spinal cord after 7 days in order to reflect the apoptotic level of spinal cord injury.In order to simulate the endoplasmic reticulum stress model,PC12 cells were divided into Control group,TG group,TG+PQS(50ng/ml)group,TG+PQS(150ng/ml)group and PQS(150ng/ml)group.We detected the apoptotic level and the expression of microtubule protein using Western blotting,Immunofluorescence and TUNEL method.In order to detect PQS’s endoplasmic reticulum stress after spinal cord injury,Western blot method was used to detect the expression of GRP78,PDI,CHOP and Cleaved-caspasel2 apoptosis factor protein after 1 days of spinal cord injury and in vitro.Results:In this study,we found that PQS can reduce spinal cord injury and promote functional recovery after spinal cord injury after SCI.The results of Western blotting and Immunofluorescence in vivo and in vitroshowed that the treatment of PQS inhibited apoptosis after acute traumatic spinal cord injury.Meanwhile,there is excess endoplasmic reticulum stress after SCI,while PQS attenuated the apoptosis induced by endoplasmic reticulum stress after acute spinal cord injury.It was also found that the protein expression level of acetyl-a-tubulin was also upregulated with the treatment of PQS.Conclusion:After acute traumatic spinal cord injury,PQS can reduce the injury of spinal cord tissue by regulation of endoplasmic reticulum stress,contributing to reduction of apoptosis and repair of axon,thus leading to the recovery of the spinal cord.Our findings indicate that PQS treatment significantly attenuated the spinal cord injury and contributes to the functional recovery.This suggests that inhibition of endoplasmic reticulum stress-induced nerve injury and apoptosis may be effective targets for treating acute traumatic spinal cord injury,suggesting that PQS could be a potential treatment for CNS injury.Part Ⅱ Panax quinquefolium saponin can reduce tissue inflammation by regulating TLR4/NF-B pathwayObjective:Inflammatory mechanism is another important factor affecting the difficult healing of acute traumatic SCI.it is also possible to promote the repair of spinal cord tissue by anti-inflammatory effect.The adult neurons in the central nervous system are rarely spontaneously regenerated in inhibitory environments.Neuroinflammation after ischemia is usually regarded as a harmful factor of nerve function,which can cause progressive deterioration of anterior horn motor neurons.Previous studies have reported that PQS has an inhibitory effect on inflammation.However,the potential impact of PQS on the inflammatory environment of acute traumatic SCI is unknown.This study is to explore the effect of PQS on the expression of inflammatory factors after SCI,and clarify the potential signaling pathways of PQS.Through this study,we will have a further understanding of the role and mechanism of PQS in the inhibitory environment of SCI.Methods:It can be divided into two directions:animal experiment and cell experiment.In vitro experiment:the healthy female Sprague-Dawley rats were randomly divided into 3 groups:Sham group,SCI group and SCI+PQS group.We detected the expression of inflammatory factors Iba-1,IL-6,TNF-α and other proteins in spinal cord by Western blotting.In order to simulate intracellular inflammation models,BV2 cells were divided into Control group,LPS group,LPS+PQS(50ng/ml)group,LPS+PQS(150ng/ml)group and PQS(150ng/ml)group.Western blot was also used to detect the expression of TLR4,IKB-α,Nuclear P65 and other inflammatory proteins after treatment in five groups.The protein expression of TNF-α and IL-6 in 5 groups of inflammatory cytokines is also detected.Results:After the treatment of PQS,the inflammatory factors(Iba-1、IL-6、TNF-α)were markedly inhibited,indicating that PQS significantly reduced the inflammatory response.And in vitro experiments showed PQS inhibited inflammation via regulation of TLR4/NFκB signaling pathway.Conclusion:After the first demonstration of acute traumatic spinal cord injury,PQS can reduce the inflammatory response in the spinal cord by regulating the TLR4/NF kappa B pathway,thus limiting the inhibitory environment after SCI,contributing to reducing axonal damage and axonal regeneration in the later stage.