The Origin Of Hair Cells After Cisplatin Injury Of Cisplatin Ototoxicity And The Role Of Shh Signaling Pathway In The Regeneration Of Hair Cells

[Background]Platinum anticancer drugs are typical ototoxic drugs.With the rapid development of platinum anticancer drugs,cisplatin is widely used in the treatment of breast cancer,head and neck tumors,testicular cancer and other cancers.Cisplatin has become one of the indispensable drugs in cancer chemotherapy.However,large doses of cisplatin can lead to auricular sensorineural hearing loss,and the higher the dose,the greater the risk.Sensorineural deafness induced by cisplatin accounts for a significant proportion of cancer patients.Animal experiments were carried out to explore the mechanism of cisplatin ototoxicity and to provide auditory protection for patients wife cisplatin.This is the ultimate purpose of our study of ototoxicity of cisplatin.In our earlier experiments,we found that cisplatin damage can delay the regeneration of hair cells compared with neomycin damage.However,whether cisplatin can inhibit proliferation and regeneration,the mechanism is still unclear.Studies have shown that Shh plays a regulatory role in cochlear development and hair cell formation,while in hair cell regeneration,however,the role and mechanism of the Shh signaling pathway in the process of hair cell regeneration is still unclear.Our previous study found that Shh signaling pathway is related to the regeneration of hair cells after cisplatin injury.Accordingly,we used cisplatin to establish a zebrafish ototoxicity model to study the regeneration of lateral hair cells in juvenile zebrafish after cisplatin injury.Furthermore,the expression and significance of Shh signaling pathway in the regeneration of lateral hair cells of juvenile zebrafish were studied.[Objective]To study on regeneration of lateral hair cells of juvenile zebrafish after cisplatin injury.To verify the expression and role of shh signaling pathway in the regeneration of lateral hair cells of juvenile zebrafish after cisplatin injury.[Method]The first experiment ues cisplatin solution to treat zebrafish fish 5 days after fertilization.Treated juvenile zebrafish with BrdU solution after withdrawal of medicine and then removed the BrdU solution.Labeled of proliferating cells and hair cells by FM1-43FX and BrdU.In the second experiment,Western blot technique was used to detect the expression of shh,smog,ptc1 and gli1 in the same pathway of shh signal in the regeneration process of lateral hair cells The regeneration of lateral hair cells in juvenile zebrafish was treated with shh signal pathway specific inhibitor PF-5274857 and agonist Smoothened Agonist(SAG)HC1 respectively for contrast the regeneration of lateral hair cells.[Result](1)The number of brdu positive cells in the experimental group after 6 to 48 hours of brdu treatment was more than that in the control group.Most of the fm1-43fin staining positive hair cells and brdu positive cells in the experimental group overlap with each other.The proliferative cells in the control group did not overlap with the fm1-43fx staining positive hair cells,(2)Shh,Smo,Ptcl and Glil proteins were detected in juvenile zebrafish of control group.Compared with the control group,the protein expression of Shh,Smo,Ptcl and Glil in young zebrafish treated with cisplatin decreased significantly at the 6th hour after removal of cisplatin.And the expression of Shh,Smo.Ptcl and Glil protein increased gradually over time.After inhibitor treatment,the expression of Shh,SMO,Ptc1 and Gli1 protein was significantly lower than that in the control group,and the protein expression did not increase with time.After treated with shh signaling pathway inhibitor,the number of lateral hair cells of juvenile zebrafish was significantly lower than that of control group,but the number of agonists was more than that of control group.[Conclusion]1.The Shh signaling pathway is involved in the normal development and functional maintenance of the lateral colliculus of juvenile zebrafish.2.The shh signaling pathway is involved in the normal development and functional maintenance of the lateral colliculus of juvenile zebrafish.3.Shh signaling pathway is activated during zebrafish regeneration and plays a positive role in the regeneration of lateral hair cells.