Kurosaka D, Kato K, Nagamoto T, Negishi K
Department of Ophthalmology, Keio University, School of Medicine, Tokyo, Japan.
Invest Ophthalmol Vis Sci. 1995 Jul;36(8):1701-8.
To determine whether basic fibroblast growth factor (bFGF) and transforming growth factor-beta 2 (TGF-beta 2) influence the contractile activity and the expression of alpha-smooth muscle actin (alpha-SMA) in bovine lens epithelial cells (LECs). To examine whether modulation of contractile activity by these growth factors depends on changes of alpha-SMA expression.
Bovine LECs were cultured in collagen gel in MED 5 medium (F-12 nutrient mixture supplemented with 5% fetal bovine serum) with or without bFGF (1 to 100 ng/ml) or TGF-beta 2 (0.01 to 10 ng/ml). To evaluate collagen gel contraction, the longest and shortest diameters of the gels were measured daily for 7 days, and the area was determined. Detection of alpha-SMA in the gels was performed immunohistochemically using a mouse monoclonal antibody against alpha-SMA. The percentage of alpha-SMA-positive cells to the total number of cells was determined.
Control gels cultured with MED 5 medium alone contracted to 15.8% +/- 3.4% of their original area after 7 days. TGF-beta 2 significantly increased this contraction in a dose-dependent manner, whereas bFGF significantly decreased it. Approximately 30% of cells in the control gels were alpha-SMA positive. TGF-beta 2 significantly increased the alpha-SMA positivity dose dependently, whereas bFGF significantly decreased it. The percent positivity for alpha-SMA and the gel area showed a significant negative correlation.
TGF-beta 2 increased collagen gel contraction and alpha-SMA expression in bovine LECs, whereas bFGF decreased these parameters. Because collagen gel contraction was correlated with alpha-SMA expression, the modulation of LEC contractile activity by growth factors may be related to an effect on alpha-SMA.
确定碱性成纤维细胞生长因子（bFGF）和转化生长因子-β2（TGF-β2）是否影响牛晶状体上皮细胞（LECs）的收缩活性以及α-平滑肌肌动蛋白（α-SMA）的表达。检查这些生长因子对收缩活性的调节是否取决于α-SMA表达的变化。
将牛LECs在MED 5培养基（补充有5%胎牛血清的F-12营养混合物）中的胶原凝胶中培养，添加或不添加bFGF（1至100 ng/ml）或TGF-β2（0.01至10 ng/ml）。为评估胶原凝胶收缩，每天测量凝胶的最长和最短直径，持续7天，并确定面积。使用抗α-SMA的小鼠单克隆抗体通过免疫组织化学法检测凝胶中的α-SMA。确定α-SMA阳性细胞占细胞总数的百分比。
仅用MED 5培养基培养的对照凝胶在7天后收缩至其原始面积的15.8%±3.4%。TGF-β2以剂量依赖性方式显著增加这种收缩，而bFGF则显著降低收缩。对照凝胶中约30%的细胞α-SMA呈阳性。TGF-β2剂量依赖性地显著增加α-SMA阳性率，而bFGF则显著降低。α-SMA的阳性百分比与凝胶面积呈显著负相关。
TGF-β2增加牛LECs中的胶原凝胶收缩和α-SMA表达，而bFGF降低这些参数。由于胶原凝胶收缩与α-SMA表达相关，生长因子对LEC收缩活性的调节可能与对α-SMA的作用有关。
