The Role Of GSDMD In The Mechanism Of Salicylate Induced Cochlear Spiral Ganglion Injury In Rats

Objective To investigate the role of GSDMD in the process of salicylate induced spiral ganglia injury in rats and the antagonistic effect of GSDMD inhibitor NSA on salicylate induced spiral ganglia injury in rats.To further improve the mechanism of salicylate induced spiral ganglion injury.Methods Forty-eight normal hearing rats were screened by Auditory Brainstem Response(ABR)detection and randomly divided into four groups.Group A: Blank control group(injection of physiological saline into the abdominal cavity);Group B: Artificial perilymph(APL)(injection of perilymph from the left ear round window niche,intraperitoneal injection of saline);Group C: salicylic acid Sodium group(left ear round window niche injection of perilymph,intraperitoneal injection of sodium salicylate);Group D: inhibitor NSA group(left ear round window niche injection of inhibitor,intraperitoneal injection of sodium salicylate).12 animals in each group,each group will be tested for ABR after 14 days of continuous administration.There were 12 rats in each group.After 14 days of continuous administration in each group,the ABR of each group was detected.Then the expression of GSDMD and IL-1β protein in the cochlea of each group was observed by immunohistochemical experiments,and the spiral ganglion neurons(SGNs)of each group were quantitatively analyzed,the protein expression of GSDMD and IL-1β in each group of rat spiral ganglion neurons were detected by Western Blot experiment,and the m RNA expression level of GSDMD and IL-1βof each group of rat spiral ganglion neurons were detected by RT-q PCR.Results The results of the ABR test showed that compared with the animals in the A and B groups,the hearing threshold of the C group was significantly increased after administration(p<0.05,p<0.05),and the D group was significantly lower than the C group(p<0.05);Immunohistochemical staining experiments showed that GSDMD and IL-1β were expressed in the spiral ganglia of the cochlea in each group,and the expression levels were significantly different(P<0.001);Western Blot experiment showed that the protein expression of GSDMD in each group was 0.563±0.087,0.527±0.120,1.314±0.213 and 0.962±0.147,respectively.The difference in protein expression was statistically significant(F=18.509,P=0.001),The protein expression of IL-1βin each group was 0.106±0.038,0.113±0.145,0.604±0.135,and0.378±0.106,respectively,and the difference in protein expression was statistically significant(F=13.134,P=0.002);The results of RT-q PCR showed that the 2-ΔΔCT values of each group of GSDMD were 1.0±0.427,0.915±0.320,6.678±1.117 and 3.231±1.079,respectively.The difference between the values was statistically significant(F=32.501,P=0.000).The 2-ΔΔCT values of IL-1βin each group were 1.0±0.525,1.109±0.547,7.789±1.052 and 3.461±1.155,respectively,and the difference between the values was statistically significant(F=40.092,P=0.000).After treatment with the inhibitor NSA,the expression of GSDMD and IL-1β in group D was lower than that in group C(P<0.05),but it was still higher than that in groups A and B(P<0.05).Conclusion GSDMD is expressed in the rat cochlear spiral ganglion;sodium salicylate may induce pyrolysis by activating GSDMD,up-regulate IL-1β,aggravate cochlear inflammation,and damage rat cochlear spiral ganglion neurons;To a certain extent,NSA could antagonize the damage of sodium salicylate to rat cochlea spiral ganglion neurons.GSDMD may become a drug target for the treatment of SGN injury in the future.