周细胞在创面修复早期血管生成中的分布与意义

Roles of pericytes in the early angiogenesis of wound healing

目的研究周细胞在创面修复肉芽组织血管生成过程中出现、分布规律与意义。方法采用常规免疫组化、双重免疫组化染色,电镜技术及形态定量分析方法观测小鼠皮肤全层切割伤模型(1～9d),特别是早期1、3、5、7d创面修复肉芽组织内血管生成过程中,周细胞的出现、分布规律。离体采用转化生长因子-β1(transforming growth factor-β1,TGF-β1)诱导分化的周细胞前体细胞10T1/2模型,观察其在细胞外基质胶立体培养的变化。结果周细胞可见于肉芽组织血管生成早期(1～7d),且周细胞阳性染色的细胞数较内皮细胞多。肉芽组织内毛细血管和周细胞的数量在伤后持续增加,直到伤后5d达峰值。周细胞在肉芽组织中还可形成条索状、腔样结构;离体培养的周细胞在细胞外基质胶内能够形成管腔样结构。结论周细胞参与了肉芽组织早期血管生成过程并可形成腔样结构,可能在血管生成中具有主导或引导作用。

Objective To study the patterns of the presence and distribution of pericytes in granulation tissue of wound repair and the related significance. Methods Granulation tissue samples were collected from mice suffered from full-thickness skin excision on 1 , 3, 5, 7, and 9 d after injury. Single and double immunohistochemical staining, electron microscopy, and quantitative analysis of morphology were applied to study the presence and distribution of pericytes during angiogenesis of granulation tissues. Meanwhile, in vitro transfor- ming growth factor-β1 （TGF-β1） -induced differentiation of 10T1/2 cell, a progenitor of pericyte, was assessed in 3-dimensional extracellular matrix （ECM） gel. Results Pericytes were found in the early stage of wound repair. The number of pericytes positive to staining was higher than that of endothelial cells in the new mi- crovessels. The number of capillaries and pericytes in granulation kept increasing till 5 d after the injury. The pericytes stimulated with TGF-β1 were able to form cell cords and clumps in vivo and cell cord- or lumina-like structure in ECM gel in vitro. Conclusion Pericytes participate in the early angiogenesis in the wound healing and the formed cell cord or lumina structure may play a crucial or guiding role in angiogenesis.