| Objective:To observe the damage of rat testis by cyclophosphamide,and to explore the role of PP2A and ?-catenin signaling pathway in rat testicular injury.And to explore whether L-camitine has protective effects on rat testicular injury through PP2A and ?-catenin signaling pathway.Methods:54 250±10 g SD male rats were randomly divided into the Vehicle group(celiac injection of saline solution for 5 days),cyclophosphamide group(20 mg/kg intraperitoneal injection for 5 days)and cyclophosphamide+L-carnitine group(first intxaperitoneal injection of L-camitine 100 mg/kg,after 1 hour,cyclophosphamide 20 mg/kg was injected intraperitoneally for 5 days),and testicular tissues were taken at 3 d,1 w,2 w,and 4 w after the end of the administration.The changes of spermatogenic epithelium and seminiferous tubules in rat testis were observed by hematoxylin and eosin(H-E)staining.The expression levels of SET,PP2A and ?-catenin in testis were detected by immunofluorescence staining and Western blotting.Results:Compared with Vehicle group,H-E staining showed that the structure of testicle was changed in the cyclophosphamide group:the structure of the seminiferous tubules were significantly changed,the wall of the tube was thinned,the number of spermatogenic cells and supporting cells were significantly reduced at each stage,and interstitial cells were significantly reduced.Spermatogonial cells at all levels in the cyclophosphamide+L-carnitine group decreased in number,but were not as serious as the cyclophosphamide group and the seminiferous tubule structure were basically intact.Immunohistochemical staining showed that positive expression of SET/PP2A/?-cateninwas observed in spermatogonia,primary spermatocytes and interstitial cells in the seminiferous tubules of each group.Compared with the Vehicle group,the expression of SET in the cyclophosphamide group decreased at 3 d and 1 w and then increased slightly,while PP2A increased first and then decreased.The expression of ?-catenin decreased first and then decreased.The above changes in the cyclophosphamide+L-camitine group were opposite to those in the cyclophosphamide group.Western blotting showed that compared with the Vehicle group,the SET expression of the cyclophosphamide group decreased from 3 d,and continued to decrease at 7 d(p<0.05),and decreased to the lowest at 2 w(p<0.001),Increased to slightly lower than the Vehicle group level at 4 w(P>0.05).The expression of PP2A in the cyclophosphamide group increased from 3 days and increased continuously on the 7th day(p<0.01),peaked at 2 w(p<0.001),at 4 ws it was still slightly higher than the Vehicle group(P>0.05),and SET and PP2A changed in the opposite direction.The expression of ?-catenin in the cyclophosphamide group decreased from 3 d,decreased continuously on the 7th day(p<0.05),and decreased to the lowest at 2 w(p<0.001).It recovered at 4 w but remained lower than the Vehicle group(P>0.05).At the same time point,compared with the cyclophosphamide group,the SET expression of the cyclophosphamide+L-camitine group was slightly lower at 3 d(P>0.05),and higher than that of the cyclophosphamide group at 7 d(p<0.05).At 2 w rose to the highest level and significantly higher than the cyclophosphamide group(p<0.001),4 w gradually decreased and higher than the cyclophosphamide group.The expression of PP2A changed in the opposite direction from SET.It started at 3 d and was lower than that of cyclophosphamide group at 7 d(p<0.001).It decreased to the lowest point at 2 w and was significantly lower than that of cyclophosphamide group(p<0.001).4 w began to rise but still below the cyclophosphamide group.?-catenin increased from 1 w and was higher than the cyclophosphamide group at the same time point(p<0.01),peaked at 2 w and higher than cyclophosphamide group(p<0.001),4 w decreased slightly but there was no statistical difference with cyclophosphamide group(P>0.05).Conclusions:(1)Cyclophosphamide can damage rat testis through PP2A and?-catenin signaling pathways.(2)L-camitine can reduce rat testicular damage induced by cyclophosphamide,possibly through PP2A and ?-catenin signaling pathways... |
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