Heparan sulfate-dependent ERK activation contributes to the overexpression of fibrotic proteins and enhanced contraction by scleroderma fibroblasts
Heparan sulfate-dependent ERK activation contributes to the overexpression of fibrotic proteins and enhanced contraction by scleroderma fibroblasts
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DOI：
10.1002/art.23146
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发表时间：
2008-02-01
影响因子：
--
通讯作者：
Eastwood, Mark
中科院分区：
文献类型：
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作者：
Chen, Yunliang;Leask, Andrew;Eastwood, Mark
目标。探讨硫酸乙酰肝素蛋白多糖和Ras/MEK/ERK在系统性硬化症(SSC)患者真皮成纤维细胞纤溶蛋白过度表达和收缩能力增强中的作用。比较MEK/ERK抑制剂U0126、硫酸肝素侧链形成抑制剂β-木糖苷和可溶性肝素对弥漫性SSC患者皮损成纤维细胞和健康对照成纤维细胞促纤维化基因表达的影响。将鉴定的蛋白质表达与成纤维细胞在胶原网中的收缩能力进行比较。使用文化力监测器测量所产生的力。用U0126抑制MEK/ERK显著减少硬皮病成纤维细胞过度表达的一组前黏附和前收缩蛋白，包括整合素α4和整合素β1。用β-木糖苷拮抗硫酸乙酰肝素侧链的形成或加入可溶性肝素可阻止ERK的激活，此外还可减少这些前黏附/收缩蛋白的表达。U0126、β-木糖苷或肝素治疗可降低真皮成纤维细胞产生的整体峰值收缩力量。用格列卫(甲磺酸伊马替尼)阻断血小板衍生生长因子受体可降低SSC成纤维细胞的整体收缩能力、Syndecan 4表达和ERK活性。本研究结果提示，硬皮病患者真皮成纤维细胞的收缩能力增强与依赖于硫酸乙酰肝素的ERK激活有关。这些结果与硬皮病真皮成纤维细胞中MEK/ERK前收缩通路调节失调的观点一致。此外，结果表明，拮抗MEK/ERK通路可能会调节硫酸乙酰肝素蛋白多糖的活性，进而可能对SSC的纤维化反应产生深远的影响。
Objective. To investigate the contribution of heparan sulfate proteoglycan and Ras/MEK/ERK to the overexpression of profibrotic proteins and the enhanced contractile ability of dermal fibroblasts from patients with systemic sclerosis (SSc; scleroderma).Methods. The effects of the MEK/ERK inhibitor U0126, the heparan sulfate side chain formation inhibitor beta-xyloside, and soluble heparin on the overexpression of profibrotic genes were compared in fibroblasts from lesional skin of patients with diffuse SSc and fibroblasts from healthy control subjects. Identified protein expressions were compared with the contractile abilities of fibroblasts while they resided within a collagen lattice. Forces generated were measured using a culture force monitor.Results. Inhibiting MEK/ERK with U0126 significantly reduced expression of a cohort of proadhesive and procontractile proteins that normally are overexpressed by scleroderma fibroblasts, including integrin alpha 4 and integrin beta 1. Antagonizing heparan sulfate side chain formation with beta-xyloside or the addition of soluble heparin prevented ERK activation, in addition to reducing the expression of these proadhesive/contractile proteins. Treatment with either U0126, beta-xyloside, or heparin resulted in a reduction in the overall peak contractile force generated by dermal fibroblasts. Blocking platelet-derived growth factor receptor with Gleevec (imatinib mesylate) reduced overall contractile ability and the elevated syndecan 4 expression and ERK activation in SSc fibroblasts.Conclusion. The results of this study suggest that heparan sulfate-dependent ERK activation contributes to the enhanced contractile ability demonstrated by dermal fibroblasts from lesional skin of patients with scleroderma. These results are consistent with the notion that the MEK/ERK procontractile pathway is dysregulated in scleroderma dermal fibroblasts. Additionally, the results suggest that antagonizing the MEK/ERK pathway is likely to modulate heparan sulfate proteoglycan activity, which in turn may have a profound effect on the fibrotic response in SSc.