Interleukin-6 receptor shedding is enhanced by interleukin-1β and tumor necrosis factor α and is partially mediated by tumor necrosis factor α-converting enzyme in osteoblast-like cells
Interleukin-6 receptor shedding is enhanced by interleukin-1β and tumor necrosis factor α and is partially mediated by tumor necrosis factor α-converting enzyme in osteoblast-like cells
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DOI：
10.1002/art.20727
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发表时间：
2005-01-01
影响因子：
--
通讯作者：
Malaise, M
中科院分区：
文献类型：
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作者：
Franchimont, N;Lambert, C;Malaise, M
Objective.白细胞介素-6（IL-6）和可溶性IL-6受体（sIL-6 R）对gp 130的激活代表了炎症条件下破骨细胞发育的替代途径。本研究的目的是研究炎症细胞因子IL-1 β和肿瘤坏死因子α（TNF α）对sIL-6 R水平的影响，并确定TNF α转化酶（TACE）在这一过程中的作用。用免疫分析法测定MG 63和SAOS-2成骨样细胞株在不同药物作用下培养液中sIL-6 R的水平。通过蛋白质免疫印迹测量TALE蛋白水平。用小干扰RNA（siRNA）或IL-6 R和TACE的表达质粒转染细胞，以确定TACE在IL-6 R脱落中的潜在参与。IL-1 β和TNF α增加MG 63成骨样细胞培养液中sIL-6 R的水平。放线菌酮或5，6-二氯苯并咪唑核苷不影响这种效果，但钙螯合剂EGTA和TALE和基质金属蛋白酶抑制剂异羟肟酸盐（Ru 36156）显着抑制。IL-1 β和TNF β对IL-6 R RNA的选择性剪接形式没有影响。当用TACE siRNA瞬时转染MG 63细胞时，sIL-6 R水平降低。IL-6 R和TACE表达质粒转染SAOS-2细胞后，sIL-6 R水平呈剂量依赖性升高。IL-1 β和TNF α介导的成骨细胞样细胞中IL-6 R脱落诱导至少部分依赖于TACE激活。
Objective. Interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6R) activation of gp130 represents an alternative pathway for osteoclast development in inflammatory conditions. The goal of the present study was to investigate changes in sIL-6R levels in response to the inflammatory cytokines IL-1beta and tumor necrosis factor alpha (TNFalpha) and to determine the role of TNFalpha-converting enzyme (TACE) in this process.Methods. Levels of sIL-6R in the culture media of MG63 and SAOS-2 osteoblast-like cell lines after exposure to various agents were determined by immunoassay. TALE protein levels were measured by Western immunoblotting. Cells were transfected with small interfering RNA (siRNA) or with an expression plasmid for IL-6R and TACE to determine the potential involvement of TACE in IL-6R shedding.Results. IL-1beta and TNFalpha increased the levels of sIL-6R in the culture media of MG63 osteoblast-like cells. This effect was not influenced by cycloheximide or 5,6-dichlorobenzimidazole riboside but was markedly inhibited by the calcium chelator EGTA and by the TALE and matrix metalloproteinase inhibitor hydroxamate (Ru36156). IL-1beta and TNFbeta had no influence on the alternatively spliced form of IL-6R RNA. Levels of sIL-6R were reduced when MG63 cells were transiently transfected with TACE siRNA. Transfection of SAOS-2 cells with expression plasmids for IL-6R and TACE produced a dose-dependent increase in sIL-6R levels.Conclusion. IL-1beta- and TNFalpha-mediated induction of IL-6R shedding in osteoblast-like cells is at least partly dependent on TACE activation.