Caspase抑制剂对小鼠心脏移植物细胞凋亡的影响

Effect of caspase inhibitor on apoptosis in mouse cardiac allograft rejection

目的 探讨Caspase抑制剂对同种异体心脏移植物细胞凋亡的影响。方法 以BALB/c小鼠为供者 ,C5 7BL/6J小鼠为受者建立异位 (颈部 )心脏移植模型 ,治疗组受者术中、术后分别给Caspase抑制剂 (Z Asp cmk) 0 .2 5mg ,对照组受者相应时间给等量的溶媒。术后观察移植心脏的存活时间 ,术后 5d处死部分受者 ,切取移植心及受者自身心脏组织 ,检测心脏组织中Caspase酶的活性及心肌细胞凋亡情况。结果 对照组移植心脏的中位存活时间为 7d ,治疗组为 13d ,二者比较 ,差异有高度显著性 (P <0 .0 1) ;移植心脏组织的Caspase 3活性 ,对照组为 (310± 83)nmolAFC·min-1·mg-1,治疗组为 (6 5± 19)nmolAFC·min-1·mg-1,受者自身心脏为 (47± 11)nmolAFC·min-1·mg-1,治疗组与受者自身心脏比较 ,差异无显著性 (P >0 .0 5 ) ,与对照组比较 ,差异有高度显著性 (P <0 .0 1) ;治疗组与对照组心肌细胞的凋亡指数分别为 7.95± 1.71及 0 .5 6± 0 .2 0 ,二者比较 ,差异有显著性 (P <0 .0 5 )。结论 Caspase抑制剂能够有效抑制小鼠心脏移植物的心肌细胞凋亡。

Objective By using heterotopic mouse heart transplantation model to investigate whether caspase inhibitors can block apoptotic cardiac myocytes in acute rejecting allograft. Methods The mice undergoing cervical heart transplantations from BALB/C to C57BL/6J were divided into two groups. In the treatment group ( n =16) animals were injected intravenously, via dorsal penile vein, with 0.25?mg Z-Asp-cmk (caspase inhibitor). In the control group ( n =16) animals were injected with PBS containing 1?% DMSO. Eight recipients from each group were observed for the survival time. Other 8 recipients were sacrificed on day 5 after transplantation and the cardiac grafts were harvested. The activity of caspase-3 was determined using a fluorometric assay system. DNA fragmentation was detected by TUNEL. Results In the treatment group the median survival time was significantly prolonged (13 days vs 7 days in controls); the activity of caspase-3 was decreased significantly in the grafts (65±19 vs 310±83 in controls, unit : nmolAFC/min-mg protein) and the number of apoptitic cardiac myocytes decreased significantly (AI, 0.56 ± 0.20 vs 7.95 ± 1.71 in controls). Conclusion The caspase inhibitor prevents cardiac myocytes in the grafts from apoptosis and thus weakens acute cardiac allograft rejection to some extent.