大鼠角膜新生血管生长与其周围基质内相关生物因子表达关系的研究

目的 探讨角膜新生血管周围间质相关生物因子与新生血管生长之间的关系.方法 实验研究.40只Wister大鼠采用NaOH滤纸烧灼法制作碱烧伤角膜新生血管模型.术后1、3及7 d,免疫荧光法检测角膜新生血管周围角膜基质间质相关生物因子包括转化生长因子β1(TGF-β1)、α平滑肌肌动蛋白(α-SMA)、成纤维细胞激活蛋白(FAP),并观察它们与新生血管之间的关系,以血小板内皮细胞黏附因子(CD31)标记血管内皮细胞.采用RT-PCR方法 检测术后3、7 d的FAP在角膜中不同位置的表达.苦味酸天狼猩红-偏振光法检测术后7 d角膜基质中主要胶原Ⅰ型和Ⅲ型胶原的改变.结果 碱烧伤后1、3及7 d角膜冰冻切片免疫荧光单染与双染显示,角膜基质首先出现TGF-β1阳性表达,然后随着新生血管的形成出现α-SMA、FAP同时阳性的细胞,正常角膜组织内无阳性表达.FAP阳性基质细胞位于CD31阳性的血管内皮细胞周围,与血管内皮细胞伴行生长,两者无明显的先后顺序.RT-PCR结果 显示,新生血管生长到达的位置出现FAP阳性表达.角膜新生血管生长后基质中Ⅰ型、Ⅲ型胶原重新排列.结论 角膜新生血管形成时,血管周围基质相关生物因子发生了改变,出现了FAP阳性的基质细胞,此细胞包绕并伴随血管内皮细胞生长;角膜基质中Ⅰ型、Ⅲ型胶原蕈新排列以适应新生血管的生长.(中华眼科杂志,2009,45:158-163)

Relationship between corneal neovascularization and various relevant biological factors in surrounding cornea stroma of rats

Objective To study the relationship between corneal neovascularization and various biological factors in corneal stroma of rats. Methods It was an experimental study. Corneal neovascularization was induced by alkali burn in 40 rats. Transforming growth factor-β1 (TGF-β1), α-smooth muscle actin (α-SMA) and fibmblast activation protein (FAP) in the stroma surrounding corneal neovascularization were detected by immunohistochemical studies on day 1, 3 and 7 after chemical burn. Platelet-endothelial cell adhesion molecule-1 (CD31) was used to identify the vascular endothelial cells. RT-PCR was used to identify FAP in the cornea 3 and 7 days after chemical burn. Picrosirius staining and polarization microscopy were used to detect changes of collagen types Ⅰ and Ⅲ in the cornea. Results After alkali burn, TGF-β1 was first expressed in the cornea stroma. Then, some stroma cells expressed both α-SMA and FAP. The FAP+ keratocytes were found surrounding the CD31+ endothelium of angiogenesis. RT-PCR study showed that FAP mRNA was only present in neovascularized cornea and not in normal cornea. Polarization microscopy revealed that the collagen types Ⅰ and Ⅲ were rearranged in neovascularized cornea. Conclusions Various biological factors in corneal stroma are changed when the cornea shows neovascularization. FAP+ keratocytes are present in the stroma, and the appearance of these cells parallels the growth of vascular endothelial cells. Collagen types Ⅰ and Ⅲ are rearranged during the process of angiogenesis. (Chin J Ophthalmol, 2009,45:158-163)