Effects Of Aldh2 Gene Expression On Ketamine-induced Bladder Inflammation And Fibrosis In Mice

BACKGROUND: Aldehyde dehydrogenase 2(aldh2)plays an important role in the development of organ injury.Long-term abuse of ketamine can cause bladder mucosal ulceration and cause lower urinary tract symptoms.The main cause is oxidative stress of the bladder epithelium caused by direct toxic effects.OBJECTIVE: To investigate the effects of aldh2 gene expression on ketamine-induced bladder inflammation and fibrosis in mice.METHODS: Twenty 8-week-old ICR male wild-type(WT)mice were randomly divided into a ketamine(50 mg/kg)group and a normal saline group,which induced for 4 weeks and 8 weeks,respectively.The bladders of mice in each group were removed,and q-PCR was used to detect the expression of aldh2 mRNA in WT mice.Subsequently,20 ICR male aldh2 knockout(KO)and 20 WT mice were selected and randomly divided into the saline control group and the ketamine treatment group(50 mg/kg).At 4 and 8 weeks,bladder tissues were removed for examination of oxidative stress,inflammation and fibrosis levels.And record the urodynamic score and general index evaluation of mice in each group.RESULTS: qPCR showed that the relative expression of aldh2 mRNA in WT ketamine-treatment group was significantly higher than that in the normal saline group(1.84±0.24 and 1.02±0.15,P<0.01).Further comparisons in the ketaminetreatment group,we found KO mice gained weight more slowly than WT mice(P< 0.01)and had increased urination evaluation rate(P <0.05).Furthermore,the level of oxidative stress product malondialdehyde(MDA)in KO mice increased,and superoxide dismutase(SOD)and reduced glutathione(GSH)decreased(P<0.05);The expression of the inflammatory cytokines interleukins 1β(IL-1β)and6(IL-6)in KO mice also increased significantly(P<0.05);Pathological tissues suggested the bladder mucosal barrier disappeared,inflammatory cell infiltration,submucosal and muscular fibrosis increased in KO mice.Western blot results and qPCR analysis further indicated that the expression levels of inflammatory proteins NF-κB,COX-2 and i NOS in KO mice were significantly increased compared with WT mice(P <0.01).The expression levels of fibrin α-SMA,TGF-β and Fibronectin were also significantly increased in KO mice(P <0.01).While compared in the normal saline group,there were no statistical differences in inflammation and fibrosis between KO and WT mice(P>0.05).CONCLUSION: Aldh2 gene may play a certain anti-inflammatory and antifibrotic role in ketamine-induced cystitis.