褪黑素对高脂饮食小鼠睾丸Bcl-2和Bax表达的影响

Effect of melatonin on expression Bcl-2 and Bax in testis of apoE-knockout mice with high-fat diet

目的探讨高脂血症对小鼠睾丸Bcl-2和Bax表达的影响及褪黑素(MT)的干预机制。方法将12只载脂蛋白E(ApoE)基因敲除的C57BL/6J雄性小鼠随机均分成高脂血症组、MT处理组,另以6只野生型C57BL/6J雄性小鼠作为对照组。12周后摘除眼球取血,测量血清胆固醇(CHO)和低密度脂蛋白胆固醇(LDL-c);免疫组化法检测Bcl-2和Bax在睾丸组织的表达。结果①高脂血症组血清CHO和LDL-c均明显高于对照组(P<0.01),高脂血症模型构建成功;与高脂血症组相比,MT处理组血清LDL-c明显降低(P<0.05),CHO无明显变化。②Bcl-2和Bax在3组小鼠睾丸组织中均有表达。与对照组相比,高脂血症组Bcl-2表达下调,Bax表达上调;与高脂血症组相比,MT处理组Bcl-2表达上调,Bax表达下调(P<0.01)。结论 Bcl-2和Bax参与高脂血症引起的睾丸细胞凋亡的调控。MT可以促进Bcl-2表达,抑制Bax表达,对高脂血症引起的睾丸损伤有一定的保护作用。

Objective To investigate the mechalisms effect of hyperlipidemia on the expression of Bcl-2 and Bax in testis of ApoE-knockout mice and the regulating of melatonin. Methods 12 ApoE-knockout C57BL/6J male mice were randomly divided into hyperlidemic group and melatonin（MT） treatment group. 6 ApoE wild-type C57BL/6J male mice were served as control group. After 12 weeks, the serum lipid profiles were detected by enzymatic deter- mination in all groups. The testis tissues were taken out from the mice for the measurement of expression of Bcl-2 and Bax by avidin-biotin-eomptex （ABC） immunohistochemical staining. Results The high-fat diet led to a signif- icant increase in serum CHO and LDL-c in ApoE-knockout mice compared with control group; no significant in- crease in serum CHO was noticed in ApoE-knockout mice with a high-fat diet in MT treatment group. Bcl-2 and Bax expressed in the testis of all groups. The expression of Bcl-2 significantly down-regulated and Bax up-regulated in hyperlipidemic group compared with control group. The increased Bel-2 expression and decreased Bax expression were observed in MT treatment group compared with the hyperlipidemic group. Conclusion Bcl-2 and Bax play a key role in testicular cell apoptosis in hyperlipidemic mice. Melatonin can increase the expression of Bcl-2 and de- crease that of Bax, which will be helpful to prevent testicular damage induced by hyperlipidemia.