Expression and Functional Roles of Caspase-5 in Inflammatory Responses of Human Retinal Pigment Epithelial Cells
Expression and Functional Roles of Caspase-5 in Inflammatory Responses of Human Retinal Pigment Epithelial Cells
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DOI：
10.1167/iovs.11-7570
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发表时间：
2011-11-01
影响因子：
4.4
通讯作者：
Elner, Victor M.
中科院分区：
文献类型：
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作者：
Bian, Zong-Mei;Elner, Susan G.;Elner, Victor M.
目的。研究caspase-5在人视网膜色素上皮（hRPE）细胞中的表达、激活和功能参与。在促炎剂IL-1 β、tnf - α、脂多糖（LPS）、干扰素- γ、单核细胞共培养、三磷酸腺苷（ATP）或内质网（ER）应激诱导剂刺激后，测定原代培养的hRPE细胞、端粒酶永生化的hTERT-RPE1细胞（hTERT-RPE1）或两者中caspase-5的表达和激活。使用免疫调节剂地塞米松（Dex）、IL-10和曲安奈德（TA）对抗促炎刺激。细胞死亡ELISA法和TUNEL染色法检测细胞凋亡。LPS和单核细胞- hrpe共培养诱导Caspase-5 mRNA表达和蛋白活化。Caspase-5激活最早出现在LPS刺激后2小时，并持续增加至24小时。同时，LPS诱导caspase-1表达及蛋白活化。Dex、IL-10和TA阻断或降低caspase-5的激活。ATP和内质网胁迫诱导剂也增强了caspase-5和-1的活化。caspase-1特异性抑制剂抑制caspase-5的表达和激活。Caspase-5敲低可降低caspase-1蛋白的表达和激活，抑制tnf α诱导的IL-8和MCP-1。与caspase-4相比，caspase-5对应激诱导的细胞凋亡的贡献是中等的。caspase - 5mrna的合成、蛋白表达和催化激活在各种促炎刺激、ATP和内质网应激诱导剂的反应中受到高度调节。caspase-5和-1之间的相互激活表明，caspase-5可能主要与caspase-1协同作用，调节hRPE炎症反应。（Invest Ophthalmol Vis Sci. 2011;52:8646-8656） DOI: 10.1167/iovs.11-7570
PURPOSE. To investigate the expression, activation, and functional involvement of caspase-5 in human retinal pigment epithelial (hRPE) cells.METHODS. Expression and activation of caspase-5 in primary cultured hRPE cells, telomerase-immortalized hTERT-RPE1 cells (hTERT-RPE1), or both, were measured after stimulation with proinflammatory agents IL-1 beta, TNF-alpha, lipopolysaccharide (LPS), interferon-gamma, monocyte coculture, adenosine triphosphate (ATP), or endoplasmic reticulum (ER) stress inducers. Immunomodulating agents dexamethasone (Dex), IL-10, and triamcinolone acetonide (TA) were used to antagonize proinflammatory stimulation. Cell death ELISA and TUNEL staining assays were used to assess apoptosis.RESULTS. Caspase-5 mRNA expression and protein activation were induced by LPS and monocyte-hRPE coculture. Caspase-5 activation appeared as early as 2 hours after challenge by LPS and consistently increased to 24 hours. Meanwhile, caspase-1 expression and protein activation were induced by LPS. Activation of caspase-5 was blocked or reduced by Dex, IL-10, and TA. Activation of caspase-5 and -1 was also enhanced by ATP and ER stress inducers. Expression and activation of caspase-5 were inhibited by a caspase-1-specific inhibitor. Caspase-5 knockdown reduced caspase-1 protein expression and activation and inhibited TNF-alpha-induced IL-8 and MCP-1. In contrast to caspase-4, the contribution of caspase-5 to stress-induced apoptosis was moderate.CONCLUSIONS. Caspase-5 mRNA synthesis, protein expression, and catalytic activation were highly regulated in response to various proinflammatory stimuli, ATP, and ER stress inducers. Mutual activation between caspase-5 and -1 suggests caspase-5 may work predominantly in concert with caspase-1 in modulating hRPE inflammatory responses. (Invest Ophthalmol Vis Sci. 2011;52:8646-8656) DOI: 10.1167/iovs.11-7570