Fibroblast activation protein alpha expression identifies activated fibroblasts after myocardial infarction
Fibroblast activation protein alpha expression identifies activated fibroblasts after myocardial infarction
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成纤维细胞活化蛋白α的表达可识别心肌梗死后活化的成纤维细胞
DOI：
10.1016/j.yjmcc.2015.08.016
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发表时间：
2015-10-01
影响因子：
5
通讯作者：
Bauersachs, Johann
中科院分区：
文献类型：
--
作者：
Tillmanns, Jochen;Hoffmann, Daniel;Bauersachs, Johann
前言：成纤维细胞激活蛋白α(FAP)是一种膜结合型丝氨酸蛋白酶，在皮肤创伤愈合过程中由活化的成纤维细胞表达。FAP在心肌梗死(MI)后的表达及其对心脏创面愈合的影响在很大程度上尚不清楚。方法：建立大鼠心肌梗死模型，采用基因芯片、Western印迹和免疫组织化学方法检测心肌梗死后3、7和28d FAP的表达。在MI后的人心脏中，鉴定了FAP成纤维细胞群，并用免疫组织化学方法鉴定了Pro-4-羟基酶β、α-平滑肌肌动蛋白、Thy-1和波形蛋白的表达。用Western印迹和ELISA法研究了转化生长因子β(1)、转化生长因子βI型受体(TGFBR1)抑制剂SB431542或MAPK抑制剂U0126以及针对Smad2和Smad3的siRNA对人心脏成纤维细胞FAP表达的影响。结果：大鼠心肌梗死后，成纤维细胞FAP表达增强，尤以心肌梗死周边区表达最强。共定位分析表明，大多数FAP(+)细胞为活化的原肌成纤维细胞和肌成纤维细胞。与此相一致的是，心肌梗死后人心脏缺血组织中FAP(+)成纤维细胞数量较多，而健康对照心脏组织中FAP(+)成纤维细胞数量较少。在体外，转化生长因子β(1)通过典型的Smad2/Smad3途径诱导FAP。FAP在成纤维细胞中的缺失降低了细胞的迁移能力，而增殖能力没有受到影响。明胶酶谱显示成纤维细胞来源的FAP具有明胶酶活性。结论：本研究首次发现心肌梗死后活化的成纤维细胞中有FAP的表达，并被转化生长因子β(1)激活。FAP对成纤维细胞迁移和明胶溶解活性的影响表明，FAP在心脏创伤愈合和重塑中具有潜在的作用。(C)2015爱思唯尔有限公司。保留所有权利。
Introduction: Fibroblast activation protein alpha (FAP) is a membrane-bound serine protease expressed by activated fibroblasts during wound healing in the skin. Expression of FAP after myocardial infarction (MI) and potential effects on cardiac wound healing are largely unknown.Methods: MI was induced in rats and FAP expression was analyzed at 3, 7 and 28 days post-MI by microarray, Western blot and immunohistochemistry. In human hearts after MI, a FAP fibroblast population was identified, and characterized by immunohistochemistry for prolyl-4-hydroxylase beta, alpha-smooth muscle actin, Thy-1 and vimentin. Signaling pathways leading to FAP expression were studied in human cardiac fibroblasts by Western blot and ELISA using TGF beta(1), TGF-beta type I-receptor (TGFbR1)-inhibitor SB431542 or the MAPK-inhibitor U0126 as well as siRNA targeting SMAD2 and SMAD3. Finally, fibroblasts were assayed for FAP-dependent migration (modified Boyden-chamber), proliferation (BrdU-assay) and gelatinolytic activity by gelatin zymography.Results: In rats, FAP expression was increased after MI especially in the pen-infarct area peaking at 7 days post-MI. Co-localization analysis identified the majority of FAP(+) cells as activated proto-myofibroblasts and myofibroblasts. Concordantly, FAP(+) fibroblasts were abundant in ischemic tissue of human hearts after MI, but not in healthy control hearts. In vitro, FAP was induced by TGF beta(1) via the canonical SMAD2/SMAD3 pathway. Depletion of FAP in fibroblasts reduced migratory capacity, while proliferation was not affected. Gelatin zymography revealed gelatinase activity by fibroblast-derived FAP.Conclusion: In this study, we show for the first time the expression of FAP in activated fibroblasts after MI and its activation by TGF beta(1). Effects of FAP on fibroblast migration and gelatinolytic activity indicate a potential role in cardiac wound healing and remodeling. (C) 2015 Elsevier Ltd. All rights reserved.