Zhang Qian-ru, Ma Jin, Zhu Tie-pei, Yao Ke
Eye Center, Second Affiliated Hospital, Zhejiang University, Hangzhou 310009, China.
Zhonghua Yan Ke Za Zhi. 2012 Jan;48(1):52-60.
To investigate the influence of vascular endothelial growth factor(VEGF) and transforming growth factor (TGF)-β(2) to human retinal pigment epithelium(RPE) cell differentiation, and the mechanism of collagen gel contraction mediated by RPE cells.
Experiment study. An in vitro collagen gel contraction assay was performed to evaluate the effect of cultured human RPE in addition of VEGF and TGF-β(2) at indicated time points (24 h, 48 h and 72 h). Three groups were established in the experiment:control group, 50 µg/L VEGF group and 5 µg/L TGF-β(2) group. The effects of both cytokines on the collagen gel contraction were analyzed by the reduced diameter of the collagen gel. And the changes of cell morphology and their transdifferentiation were assessed to estimate the possible connection between RPE transdifferentiation and collagen gel contraction. One-way ANOVA was used in conjunction with SNK-q test to assess statistical significance at different time periods within groups.
There were differences on collagen gel contraction rates among VEGF group [(34.7 ± 3.1)%, (44.3 ± 6.0)%, (44.0 ± 7.2)%], TGF-β(2) group [(29.3 ± 3.1)%, (31.7 ± 3.5)%, (29.0 ± 3.6)%] and control group [(20.0 ± 0.5)%, (17.3 ± 3.6)%, (19.1 ± 0.8)%] at 24 h, 48 h and 72 h after cultured (24 h: F = 26.220, P = 0.001; 48 h: F = 26.796, P = 0.001; 72 h: F = 21.522, P = 0.002), and on each time point two two comparison in the three groups (SNK-q test, P < 0.05). There were differences on protein expression level of α-smooth muscle actin (α-SMA) in 50 µg/L VEGF group and 5 µg/L TGF-β(2) group at difference time points, respectively (TGF-β(2) group: F = 1.134, P = 0.000; each time point: SNK-q test, P < 0.05; VEGF group: F = 279.179, P = 0.000; each time point: SNK-q test, P < 0.05). Moreover, TGF-β(2) (5 µg/L) demonstrated stronger and more permanent gel contraction than VEGF (50 µg/L) (6 h: F = 3.646, P = 0.000; 24 h: F = 18.706, P = 0.003; 48 h: F = 124.195, P = 0.000; 72 h: F = 76.811, P = 0.000). RPE cells' form happened fibroblasts sample transformation in both VEGF group and TGF-β(2) group.
Both VEGF and TGF-β(2) can induce the collagen gel contraction, partly by means of inducing the expression of α-SMA and RPE contraction, which may thus contribute to the explanations of vitro-retinal diseases.
探讨血管内皮生长因子（VEGF）和转化生长因子（TGF）-β2对人视网膜色素上皮（RPE）细胞分化的影响，以及RPE细胞介导胶原凝胶收缩的机制。
实验研究。进行体外胶原凝胶收缩试验，以评估在指定时间点（24小时、48小时和72小时）添加VEGF和TGF-β2培养的人RPE的作用。实验设立三组：对照组、50μg/L VEGF组和5μg/L TGF-β2组。通过胶原凝胶直径减小分析两种细胞因子对胶原凝胶收缩的影响。评估细胞形态变化及其转分化情况，以估计RPE转分化与胶原凝胶收缩之间的可能联系。采用单因素方差分析结合SNK-q检验评估组内不同时间段的统计学意义。
培养24小时、48小时和72小时后，VEGF组[（34.7±3.1）%，（44.3±6.0）%，（44.0±7.2）%]、TGF-β2组[（29.3±3.1）%，（31.7±3.5）%，（29.0±3.6）%]和对照组[（20.0±0.5）%，（17.3±3.6）%，（19.1±0.8）%]的胶原凝胶收缩率存在差异（24小时：F=26.220，P=0.001；48小时：F=26.796，P=0.001；72小时：F=21.522，P=0.002），且三组在各时间点两两比较（SNK-q检验，P<0.05）。50μg/L VEGF组和5μg/L TGF-β2组在不同时间点的α-平滑肌肌动蛋白（α-SMA）蛋白表达水平存在差异（TGF-β2组：F=1.134，P=0.000；各时间点：SNK-q检验，P<0.05；VEGF组：F=279.179，P=0.000；各时间点：SNK-q检验，P<0.05）。此外，TGF-β2（5μg/L）比VEGF（50μg/L）表现出更强且更持久的凝胶收缩（6小时：F=3.646，P=0.000；24小时：F=18.706，P=0.003；48小时：F=124.195，P=0.000；72小时：F=76.811，P=0.000）。VEGF组和TGF-β2组的RPE细胞形态均发生成纤维细胞样转变。
VEGF和TGF-β2均可诱导胶原凝胶收缩，部分是通过诱导α-SMA表达和RPE收缩实现的，这可能有助于解释体外视网膜疾病。
