Smad7 suppresses the inhibitory effect of TGF-β2 on corneal endothelial cell proliferation and accelerates corneal endothelial wound closure in vitro
Smad7 suppresses the inhibitory effect of TGF-β2 on corneal endothelial cell proliferation and accelerates corneal endothelial wound closure in vitro
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DOI：
10.1097/00003226-200303000-00015
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发表时间：
2003-03-01
期刊：
影响因子：
2.8
通讯作者：
Kanai, A
中科院分区：
文献类型：
--
作者：
Funaki, T;Nakao, A;Kanai, A
目的.转化生长因子-β 2（TGF-β 2）对角膜内皮细胞增殖的抑制活性被认为是角膜内皮细胞再生能力有限的原因，这可能与当许多角膜内皮细胞由于各种应力而丧失时角膜透明度受损有关。我们确定了TGF-β信号的细胞内拮抗剂Smad 7是否调节TGF-β 2或房水对角膜内皮细胞增殖的抑制活性。方法.用携带Smad 7的腺病毒感染培养的兔角膜内皮细胞，使用胸苷摄取测定来评价Smad 7对TGF-β 2或水体液介导的角膜内皮细胞增殖抑制的作用。免疫印迹法检测Smad及细胞周期相关蛋白的表达。此外，在表达Smad 7的培养的兔角膜内皮细胞的单层上制作小刮伤，以检查Smad 7对体外伤口愈合过程的影响。结果Smad 7的过表达可消除TGF-β 2或房水对培养的兔角膜内皮细胞增殖的抑制作用，这种抑制作用与抑制Smad 2的磷酸化和下调p27 kip 1有关。Smad 7-过表达培养的兔角膜内皮细胞表现出较短的伤口闭合时间比LacZ-表达细胞的存在下，房水。结论过表达Smad 7可抑制TGF-β 2或房水对角膜内皮细胞增殖的抑制作用，并加速角膜内皮伤口的体外闭合。因此，角膜内皮细胞中Smad 7表达的修饰可适用于治疗受伤的角膜内皮。
Purpose. The inhibitory activity of transforming growth factor-beta2 (TGF-beta2) on corneal endothelial cell proliferation is thought to be a cause of the limited regenerative capacity of corneal endothelial cells that may be related to impaired corneal transparency when many corneal endothelial cells are lost due to various stresses. We determined whether Smad7, an intracellular antagonist of TGF-beta signaling, regulated the inhibitory activity of TGF-beta2 or aqueous humor on corneal endothelial cell proliferation. Methods. The effect of Smad7 on TGF-beta2- or aqueous humor-mediated inhibition of corneal endothelial cell proliferation was evaluated using thymidine uptake assay with cultured rabbit corneal endothelial cells infected with adenovirus carrying Smad7. Expression of Smad or cell cycle-related proteins was detected by immunoblotting. In addition, a small scrape wound was made across a monolayer of Smad7-expressing cultured rabbit corneal endothelial cells to examine the effect of Smad7 on the wound-healing process in vitro. Results. Overexpression of Smad7 abolished the inhibitory effect of TGF-beta2 or aqueous humor on the proliferation of cultured rabbit corneal endothelial cells associated with the inhibition of phosphorylation of Smad2 and downregulation of p27kip1. Smad7-overexpressing cultured rabbit corneal endothelial cells exhibited shorter wound closure time in the presence of aqueous humor than LacZ-expressing cells. Conclusion. Overexpression of Smad7 suppressed the inhibitory effect of TGF-beta2 or aqueous humor on corneal endothelial cell proliferation and accelerated corneal endothelial wound closure in vitro. Modification of Smad7 expression in corneal endothelial cells may thus have applicability in the treatment of wounded corneal endothelium.