Expression of variant fibronectins in wound healing: cellular source and biological activity of the EIIIA segment in rat hepatic fibrogenesis.
Expression of variant fibronectins in wound healing: cellular source and biological activity of the EIIIA segment in rat hepatic fibrogenesis.
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DOI：
10.1083/jcb.127.6.2037
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发表时间：
1994-12
影响因子：
7.8
通讯作者：
Bissell, D M
中科院分区：
文献类型：
--
作者：
Jarnagin, W R;Rockey, D C;Koteliansky, V E;Wang, S S;Bissell, D M
我们已经研究了两种纤维连接蛋白亚型，EIIIA和EIIIB的细胞特异性表达，在实验性肝纤维化诱导的胆管结扎。在mRNA水平上，EIIIA和EIIIB在正常肝脏中检测不到，但在纤维化之前表达早期损伤。这些变化的细胞来源通过在胆管结扎后的不同时间点将肝脏分离成其组成细胞群并从新鲜分离物中提取RNA来确定。正常肝窦内皮细胞中含EIIIA的纤连蛋白mRNA检测不到，但在损伤后12 h内迅速增加。相比之下，EIIIB形式仅限于肝脂细胞（Ito或脂肪储存细胞），仅在12-24小时的滞后后出现：在窦内皮细胞中最小。两种形式在肝细胞中均极轻微。在蛋白质水平，EIIIA的纤维连接蛋白显着增加，在两天内的损伤，并表现出正弦曲线分布。在原代培养中证实了内皮细胞分泌这种形式。基质原位沉积的内皮细胞从受伤的肝脏加速转换（“激活”）的正常脂肪细胞成肌纤维细胞样细胞，和预处理的基质与单克隆抗体的EIIIA段阻断这种反应。最后，含有EIIIA片段的重组纤连蛋白肽对培养的脂肪细胞具有刺激作用。我们的结论是，EIIIA纤维连接蛋白的表达窦内皮细胞是一个关键的早期事件在肝脏的损伤反应和EIIIA段是生物活性的，介导的转换脂肪细胞肌成纤维细胞。
We have examined the cell-specific expression of two fibronectin isoforms, EIIIA and EIIIB, during experimental hepatic fibrosis induced by ligation of the biliary duct. AT the mRNA level, EIIIA and EIIIB were undetectable in normal liver but expressed early injury, preceding fibrosis. The cellular sources of these changes were determined by fractionating the liver at various time points after bile duct ligation into its constituent cell populations and extracting RNA from the fresh isolates. EIIIA-containing fibronectin mRNA was undetectable in normal sinusoidal endothelial cells but increased rapidly within 12 h of injury. By contrast, the EIIIB form was restricted to hepatic lipocytes (Ito or fat-storing cells) and appeared only after a lag of 12-24 h: it was minimal in sinusoidal endothelial cells. Both forms were minimal in hepatocytes. At the protein level, EIIIA-containing fibronectin was markedly increased within two days of injury and exhibited a sinusoidal distribution. Secretion of this form by endothelial cells was confirmed in primary culture. Matrices deposited in situ by endothelial cells from injured liver accelerated the conversion ("activation") of normal lipocytes to myofibroblast-like cells, and pretreatment of matrices with monoclonal antibody to the EIIIA segment blocked this response. Finally, recombinant fibronectin peptide containing the EIIIA segment was stimulatory to lipocytes in culture. We conclude that expression of EIIIA fibronectin by sinusoidal endothelial cells is a critical early event in the liver's response to injury and that the EIIIA segment is biologically active, mediating the conversion of lipocytes to myofibroblasts.