p38 MAPK mediates the expression of type I collagen induced by TGF-β2 in human retinal pigment epithelial cells ARPE-19
p38 MAPK mediates the expression of type I collagen induced by TGF-β2 in human retinal pigment epithelial cells ARPE-19
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DOI：
10.1167/iovs.03-1276
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发表时间：
2004-07-01
影响因子：
4.4
通讯作者：
Yoshioka, H
中科院分区：
文献类型：
--
作者：
Kimoto, K;Nakatsuka, K;Yoshioka, H
目的.转化生长因子（TGF）-β被认为是增殖性玻璃体视网膜病变的关键介质，但TGF-β诱导细胞外基质蛋白（ECM）合成的细胞机制尚未完全了解。本研究旨在探讨丝裂原活化蛋白激酶（MAPK）通路是否参与TGF-β 2诱导的视网膜色素上皮细胞胶原蛋白表达。培养人视网膜色素上皮细胞ARPE-19，并用不同浓度的TGF β 2刺激。实时定量RT-PCR检测TGF-β 2诱导的I型胶原基因（COL 1A 1、COL 1A 2）表达。通过培养基中I型C-末端前肽（PICP）的浓度评价I型胶原的合成。用抗磷酸化p38和抗磷酸化细胞外信号调节激酶（ERK）1/2抗体通过免疫印迹评估TGF-β 2对MAPK通路的激活。使用生化抑制剂评估MAPK的作用。为了检测COL 1A 1和COL 1A 2的转录活性，还进行了荧光素酶报告基因测定。TGF-β 2激活COL 1A 1和COL 1A 2的mRNA表达和I型胶原合成。ERK和p38 MAPK通路也被TGF-β 2激活。生化阻断p38 MAPK激活，而不是ERK激活，抑制TGF-β 2诱导的I型胶原mRNA表达和I型胶原合成。此外，阻断p38 MAPK通路可抑制TGF-β 2诱导的COL 1A 1和COL 1A 2启动子活性的增加。TGF-β 2激活p38 MAPK，并且p38 MAPK在将TGF-β 2信号传递到视网膜色素上皮中的I型胶原蛋白产生中起作用。
PURPOSE. Transforming growth factor (TGF)-beta has been implicated as the key mediator of proliferative vitreoretinopathy, but the cellular mechanisms by which TGF-beta induces extracellular matrix protein (ECM) synthesis are not fully understood. The current study was conducted to examine whether the mitogen-activated protein kinase ( MAPK) pathway is involved in TGF-beta2-induced collagen expression in retinal pigment epithelial cells.METHODS. Human retinal pigment epithelial cells ARPE-19 were cultured and stimulated with various concentrations of TGFbeta2. The type I collagen gene (COL1A1, COL1A2) expression induced by TGF-beta2 was evaluated by real-time RT-PCR. Synthesis of type I collagen was evaluated by the concentration of the C-terminal propeptide of type I ( PICP) in the medium. The activation of MAPK pathways by TGF-beta2 was assessed by immunoblot with anti-phospho-p38 and anti-phospho-extracellular signal-regulated kinase (ERK)1/2 antibodies. The role of MAPK was assessed using biochemical inhibitors. To examine the transcriptional activities of COL1A1 and COL1A2, luciferase reporter assays were also performed.RESULTS. mRNA expression of COL1A1 and COL1A2 and type I collagen synthesis were activated by TGF-beta2. Both ERK and p38 MAPK pathways were also activated by TGF-beta2. The biochemical blockade of p38 MAPK activation, but not ERK activation, inhibited TGF-beta2-induced type I collagen mRNA expression and type I collagen synthesis. Moreover, blockade of the p38 MAPK pathway inhibited the increase in both COL1A1 and COL1A2 promoter activities when induced by TGF-beta2.CONCLUSIONS. TGF-beta2 activates p38 MAPK and p38 MAPK plays a role in relaying the TGF-beta2 signal to type I collagen production in the retinal pigment epithelium.