大鼠皮肤挫伤修复过程中caspase-6的表达及其时间规律性

A Study on the Time-Dependent Expression of Caspase-6 during Repair of Skin Contusion in Rats

目的探讨皮肤挫伤修复过程中,caspase-6在挫伤区及挫伤周边区不同时间表达的变化规律。方法应用免疫组化染色、Westernblot技术显示caspase-6在皮肤挫伤区及挫伤周边区炎性细胞中的阳性表达和激活情况。结果伤后3h,挫伤区内浸润的少量多核粒细胞的胞质中caspase-6呈弱阳性表达,阳性率为(25.78±1.38)%;伤后12h,阳性表达增强明显,阳性率为(47.70±5.14)%;伤后3d,几乎所有多核粒细胞、单核细胞和成纤维细胞中caspase-6呈强阳性表达,阳性率为(54.58±5.64)%,表达达高峰,以后逐渐下降。Westernblot实验证明,caspase-6酶原表达呈现时间规律性变化。结论大鼠皮肤挫伤修复过程中,caspase-6在挫伤后的炎症反应中发挥重要作用;同时,caspase-6在挫伤区内多核粒细胞、单核细胞及成纤维细胞中的表达呈规律性变化,可对挫伤时间的推断提供参考。

Objective To investigate the expression of caspase-6 in rat skin contusion and its surrounding areas during repairment. Methods Immunohistochemical SP method and Western blot technique were used to study the expression and activation of caspase-6 in rat skin contusion and its surrounding areas. Results Weak expression of caspase-6 was detected in cytoplasms of polymorphonuchear cells （PMNs） infiltrated in the injured area at 3 hours post-contusion. The ratio of the caspase-6 positive cells was low （25.78±1.38）%. The expression of caspase-6 was increased prominently （47.70±5.14）% at 12hours postcontusion. Almost all of the PMNs, mononuclear cells （MNCs） and fibroblastic cells （FBCs） were caspase-6 positive with both cytoplasm and nucleus staining （54.58±5.64）% on post-contusion day 3. The expression of caspase-6 decreased gradually thereafter. The expression of the 34-kDa pro-caspase-6 was detected by Western blot in both control and the post-contusion groups with time dependent dynamics. Conclusion These results suggest that caspase-6 may play a major role in trauma-lnduced inflammatory response. Since caspase-6 shows a timely dependent expression in PMNs, MNCs and FBCs during skin injury repair in rat, it may be used as a marker for the contusion age determination.