小鼠皮肤切创愈合过程中caspase-9、-3表达的研究

目的研究caspase-9、-3在小鼠皮肤切创愈合过程中的表达及其变化规律。方法在小鼠背部正中制作皮肤全层切创模型,应用免疫组化染色技术观察切创及切创周边区内caspase-9、-3的表达情况,以无切创的小鼠皮肤作为对照。结果对照组中caspase-9、-3表达于表皮层,毛囊及皮脂腺。伤后3h损伤区及损伤周边区中可见少量多核粒细胞表达caspase-9、-3,6~24h,部分浸润的多核粒细胞和单核细胞caspase-9、-3阳性,此后caspase-9、-3阳性细胞逐渐以单核细胞和成纤维细胞为主。伤后caspase-9、-3阳性细胞率逐渐升高并在3d达到高峰,此后逐渐下降,至14d最低。结论caspase-9、-3可能引发正常小鼠皮肤表皮、毛囊和皮脂腺细胞的凋亡并参与正常皮肤细胞的自我更新;在小鼠皮肤切创愈合过程中,caspase-9、-3在多核粒细胞、单核细胞及成纤维细胞中表达,其时序性变化规律可望用于皮肤切创损伤时间的判定。

A study on the expression of caspase-9 and caspase-3 during the skin incised wound healing in mice/

Objective To investigate the time-dependent expressions of caspase-9 and caspase-3 during skin incised wound healing in mice and their applicabilities to estimation of wound age.Methods An incised wound was made in the mouse dorsal skin.By S-P methods,the expressions of caspase-9 and caspase-3 were studied in cutaneous incised wound as well as in normal skin in control mice.Results Caspase-9-and caspase-3-positive cells were detected in epidermis,hair follicles,and sebaceous glands in control skin.3h after injury,caspase-9 or caspase-3 was observed in polymorphonuclear cells(PMNs) in the wound and peripheral region.From 6h to 24h post-wounding,caspase-9 and caspase-3 immunoreactivity was identified in part of infiltrating PMNs and mononuclear cells(MNCs).Afterwards,the MNCs and fibroblastic cells(FBCs) accounted for the most part of the caspase-9-and caspase-3-positive cells.The percentage of caspase-9 or caspase-3 positive cells was low in the wound specimens aged from 0h to 3h,and maximized in parallel in the specimens aged 3 day,which decreased and minimized in the specimens aged 14 day.Conclusion The results suggest that caspase-9 and caspase-3 may be involved in the apoptosis of epidermis,hair follicle and sebaceous gland cells and take part inthe homeostasis of normal skin.Caspase-9and caspase-3 are expressed in PMNs,MNCs and FBCs during skin incised wound healing in mice and may be used as the markers for wound age determination.