碱性成纤维细胞生长因子在不同发育阶段大鼠和小鼠皮肤的表达特征及其意义

Expression of basic fibroblast growth factor (bFGF) in rat and mouse skin and its biological significance

目的 研究碱性成纤维细胞生长因子 (bFGF)蛋白、基因以及因子受体在大鼠和小鼠不同发育阶段表皮和真皮的表达特征及其可能的生物学意义。方法 取胚胎期、新生、青年和成年大小鼠皮肤 ,部分经超低温冷冻后用于逆转录聚合酶链反应 (RT PCR)检测 ,部分经 4%多聚甲醛固定、包埋与切片后用SP免疫组织化学、原位杂交以及RT PCR方法确定bFGF蛋白、基因以及因子受体的定位与表达特征。结果 bFGF蛋白的阳性表达可见于新生、青年以及成年 3个发育阶段大鼠皮肤 ,主要位于表皮细胞、真皮成纤维细胞、毛囊上皮细胞和血管内皮细胞胞浆。但在胚胎大鼠皮肤bFGF的表达为阴性。bFGF受体与bFGF基因在以上 4个不同发育阶段大鼠表皮与真皮均有表达 ,其表达量随动物的生长而有所增加。bFGF蛋白、基因以及受体在小鼠 4种不同发育阶段的表皮与真皮均有表达 ,其定位与表达特征与bFGF在青年期大鼠皮肤一致。结论 bFGF蛋白及其相应受体在不同发育阶段大小鼠皮肤的强阳性表达 ,表明它们以自分泌方式对上皮的生长、发育、表型维持以及损伤后的修复十分重要。而大鼠胚胎皮肤bFGF低表达或无表达的结果表明它可能是动物胚胎创伤后无瘢痕愈合的原因之一 。

Objective To explore the expression of basic fibroblast growth factor (bFGF) in rat and mouse skin and to explore its potential biological singificance. Methods Skins at the back of rats and mice at embryonic, newborn, youth and adult stages were taken, frozen at ultra low temperature, or embedded and microtomed. Immunohistochemical method, hybridization and RT PCR techniques were used to observe the localization and expression amount of growth factor protein, bFGF receptor and bFGF gene. Results Positive immunohistochemical signal of bFGF protein could be found in the skins from newborn, youth and adult rats, mainly in the cytoplasm of epithelial cells, hair follicle, endothelial cells and fibroblasts, and could not be found in the skin of embryonic rats. With the increase in age, the expression amount of bFGF increased. The expression of bFGF receptor and bFGF gene could be found in the skin from all developmental stages in rats and mice. Conclusion The endogenous bFGF is involved in the epidermal development in embryonic stage and in the wound healing in adult stage. However, bFGF may only plays an important role in tissue repair in adult stage after injury. The absence of bFGF may be one of the reasons for the scarless healing in embryonic stage as shown by the negative expression of bFGF in skin from embryonic rats.