Effect Of Methylprednisolone On Apoptosis And Autophagy After Spinal Cord Injury

ObjectiveThis study sought to investigate the exact effect of MP on SCI,and its mechanism,It could provide experimental evidence for the therapy of spinal cord injury.Methods1.The model of SCI was established by using the modified Allen's method on T10 of spinal cord,The ultrastructure.of nerve tissue were observed by transmission electron microscopy.2.BBB scores were analyzed at different time points?normal,1d,3d,7d,14 d,21d,28d?to evaluation themotor function of rats after spinal cord injury..3.The protective effect of H₂O₂-induced oxidative damage in N2a cells by MP was evaluated using MTT.4.Pretreatment of N2a cells with concentrations of 10?M or less MP in30 min,then or the cultured N2a cells were added to 100 ?M H₂O₂ for 24 h.Observe the cell morphological changes in different group of N2a cells.5.We use flow cytometry and Western Blot to detect the apoptosis of N2a cells.6.We observed the localization of autophagy protein LC3-B by immunofluorescence,the expression of autophagy-related protein was monitored by Western blot.Results1.TEM results showed that autophagosome was significantly increased.activated after spinal cord injury at 1 day.2.Basso,Beattie,and Bresnahan?BBB?scores showed that the function of motor neurons were visibly preserved by MP after SCI in rats.3.MTT test results found that methylprednisolone pretreatment group protected N2a cells against H₂O₂-induced oxidative damage.4.We found MP would able to maintain the shape and the number of injuried N2a cells under inverted phase contrast microscope.5.Flow cytometry and Western blot showed that MP significantly reduced the percentage of apoptotic cells.6.Immunofluorescence results showed that LC3-B was mainly expressed in the cytoplasm,Western blot results showed that MP down regulate the expression of LC3-B and Beclin-1.Conclusions1.The findings of this study showed that MP plays a neuroprotective effect in spinal cord-injured rats.2.MP exerts neuroprotective effects via inhibition of autophagy and apoptosis.