Yang Yong-mei, Wu Xin-yi, Du Li-qun
Department of Ophthalmology, Jinan Center Hospital, Medical College of Shandong University, Jinan 250013, China.
Zhonghua Yan Ke Za Zhi. 2006 Oct;42(10):918-24.
To study the expression and location of connective tissue growth factor (CTGF) and transforming growth factor-beta(1) (TGF-beta(1)) protein and mRNA in rabbit cornea during the wound healing process. To assess the interaction between CTGF and TGF-beta(1), as well as the Smad signaling pathway involved.
Twenty-six Albino white rabbits were used as experimental animals and randomly divided into 4 groups: (1) CONTROL GROUP: two rabbits. (2) Simple corneal injury group: a 3 mm diameter and 0.05 mm depth corneal tissue was excised by a trephine at the anterior central cornea as a corneal wound model in 12 rabbits. Two rabbits were randomly sacrificed at 2 h, 6 h, 1 d, 3 d, 7 d and 21 d after the trauma. (3) TGF-beta(1) antibodies treated group: 6 rabbits were injected with TGF-beta(1) antibodies (15.5 microg) subconjunctivally after corneal trephine. Two rabbits were randomly sacrificed at 3 d, 7 d and 21 d after the injection. (4) Smad4 antibodies treated group: 6 rabbits were injected with Smad4 antibodies (20 microg) subconjunctivally after corneal trephine. Two rabbits were randomly sacrificed at 3 d, 7 d and 21 d after the injection. Protein of CTGF, TGF-beta(1), and FN was assessed with immunohistochemistry. CTGF and type one collagen mRNA were measured in by in situ hybridization.
(1) CTGF protein or mRNA did not exist in normal rabbit corneas, but TGF-beta(1) protein was expressed in normal rabbit cornea epithelium. (2) Cornea fibroblasts activated 6 h after the operation. Expression of CTGF, TGF-beta(1), FN protein and mRNA of CTGF and type one collagen were upregulated after cornea injury, and reached the highest level in 3 days. The expression was reduced to the basal level 21 days later. (3) Injection of TGF-beta(1) antibodies reduced the expression of CTGF, TGF-beta(1) and FN in the cornea stroma and down-regulated the expression of CTGF in corneal epithelial cells. (4) Injection of Smad4 antibodies inhibited the expression of TGF in the stroma but did not change the expression of CTGF.
Injury can upregulate the expression of CTGF, TGF-beta(1), FN and type one collagen proteins and mRNA of CTGF and TGF-beta(1). TGF-beta(1) and CTGF affect the wound healing process. TGF can induce the activation of corneal fibroblasts and upregulate the expression of CTGF. CTGF modulates the production of FN and Type one collagen. These data support the hypothesis that TGF-beta(1) and CTGF promote cornea scar formation and imply that the regulation of CTGF and TGF-beta(1) synthesis may be a therapy target for reducing corneal scarring.
研究结缔组织生长因子（CTGF）和转化生长因子-β1（TGF-β1）蛋白及mRNA在兔角膜伤口愈合过程中的表达及定位。评估CTGF与TGF-β1之间的相互作用以及相关的Smad信号通路。
26只白化白兔作为实验动物，随机分为4组：（1）对照组：2只兔子。（2）单纯角膜损伤组：用环钻在12只兔子的中央前角膜切除直径3mm、深0.05mm的角膜组织作为角膜伤口模型。伤后2小时、6小时、1天、3天、7天和21天随机处死2只兔子。（3）TGF-β1抗体处理组：6只兔子角膜环钻后结膜下注射TGF-β1抗体（15.5μg）。注射后3天、7天和21天随机处死2只兔子。（4）Smad4抗体处理组：6只兔子角膜环钻后结膜下注射Smad4抗体（20μg）。注射后3天、7天和21天随机处死2只兔子。采用免疫组织化学法检测CTGF、TGF-β1和FN蛋白。通过原位杂交检测CTGF和Ⅰ型胶原mRNA。
（1）正常兔角膜中不存在CTGF蛋白或mRNA，但TGF-β1蛋白在正常兔角膜上皮中表达。（2）术后6小时角膜成纤维细胞被激活。角膜损伤后CTGF、TGF-β1、FN蛋白及CTGF和Ⅰ型胶原mRNA表达上调，并在3天达到最高水平。21天后表达降至基础水平。（3）注射TGF-β1抗体降低了角膜基质中CTGF、TGF-β1和FN的表达，并下调了角膜上皮细胞中CTGF的表达。（4）注射Smad4抗体抑制了基质中TGF的表达，但未改变CTGF的表达。
损伤可上调CTGF、TGF-β1、FN以及CTGF和TGF-β1的Ⅰ型胶原蛋白和mRNA的表达。TGF-β1和CTGF影响伤口愈合过程。TGF可诱导角膜成纤维细胞活化并上调CTGF的表达。CTGF调节FN和Ⅰ型胶原的产生。这些数据支持TGF-β1和CTGF促进角膜瘢痕形成的假说，并表明调节CTGF和TGF-β1的合成可能是减少角膜瘢痕的治疗靶点。
