Sal idroside Modulates cAMP/PKA/CREB Signaling Pathway to Inhibit Ci splatin-induced Damages of Cochlear Hair Cells and Spiral Ganglion Neurons in Mice / 听力学及言语疾病杂志

ABSTRACT

Objective To investigate the ameliorating effect of salidroside(SAL)on cisplatin(CIS)-induced damages of cochlear hair cells(CHC)and spiral ganglion neurons(SGNs)and its relationship with cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)/cAMP response element binding protein(CREB)pathway.Methods The cochlear basilar membranes of newborn C 57BL/6 mice were isolated and separated into control(C)group,CIS group,SAL group,SAL+SQ22536(cAMP inhibitor)group and SAL+H-89(PKA inhibitor)group,20 per group.Immunofluorescence staining was applied to observe the damages of CHC and SGNs.The kits were applied to detect the contents of ROS and cAMP in the basement membrane of the cochlea.Western blot was applied to detect the protein levels of PKA,p-CREB,CREB,Bcl-2,BDNF,and NF-M.Results CHC in CIS group were disorderly arranged and enlarged in size,SGNs had fragmented nuclei and lost neurites.SAL alleviated the damages of CHC and SGNs.Compared with the C group,the numbers of CHC and SGNs in the CIS group were less(P＜0.05),the contents of ROS and cAMP,and the levels of PKA,BDNF,NF-M,Bcl-2 proteins and p-CREB/CREB were higher(P＜0.05).Compared with the CIS group,the numbers of CHC and SGNs in the SAL group were higher(P＜0.05),the content of ROS was lower(P＜0.05),the content of cAMP,and the levels of PKA,BD-NF,NF-M,Bcl-2 proteins and p-CREB/CREB were higher(P＜0.05).Both SQ22536 and H-89 reversed the pro-tective effects of SAL on CHC and SGNs.Conclusion SAL may promote the expression of anti-apoptotic proteins and neuroprotective factors by activating the cAMP/PKA/CREB pathway to alleviate the damages of CHC and SGNs caused by CIS.