Axl Upregulate Autophagy In Experimental Autoimmune Encephalomyelitis Via PI3K/Akt/mTOR Signaling Pathway

Objective:To investigate the correlation between Axl receptors and autophagy with experimental autoimmune encephalomyelitis and its severity in mice,and further demonstrate that Axl receptors may regulate autophagy levels through PI3K/Akt/mTOR signaling pathway and affect the severity of EAE pathogenesis.Methods:First,We verified whether there was a correlation between Axl receptors and their autophagy levels in EAE mice,and investigated the extent of Axl expression and changes in autophagy levels at different onset times.Then we further verified whether Axl affected the progression of EAE disease by regulating autophagy levels by in vitro（microglia control group,LPS model group,Axl knockdown + LPS group）and in vivo（standard control group,EAE group,Axl knockdown + EAE group）experiments using WB,PCR,ELISA,immunohistochemistry,pathological staining,transmission electron microscopy,and other experimental methods,and clarified that whether Axl-mediated upregulation of autophagy levels in microglia and EAE models was accomplished through the PI3K/Akt/mTOR signaling pathway.Results:1.The changes in autophagy levels and Axl receptor expression in the EAE model tended to be consistent;compared with healthy controls,autophagy levels were upregulated during EAE and decreased during disease recovery;Axl receptor expression was upregulated during EAE,peaked at day 15 after immunization,and fell at day 30;after Axl knockdown,autophagy levels tended to decline,the knockdown model group showed significantly higher inflammation status than the model group.2.Validation of Axl-mediated changes in autophagy levels through PI3K/Akt/mTOR during EAE by in vitro and in vivo experiments.After the knockdown of the Axl gene in vitro and in vivo,the autophagy levels is decreased in the knockdown model group compared to the average model group,the expression of P-P13 K,P-Akt,and P-mTOR also were upregulated.Conclusion:1.Both Axl receptor and autophagy levels changed significantly during the disease in the EAE model.2.When Axl knockdown was followed by a more severe inflammatory response in both in vivo and in vitro models of inflammation,which may be related to suppressed levels of autophagy.3.Axl receptors likely upregulated autophagy levels in EAE mice by inhibiting PI3K/Akt/mTOR signaling pathway...