Genetic Regulation of Fibroblast Activation and Proliferation in Cardiac Fibrosis.
Genetic Regulation of Fibroblast Activation and Proliferation in Cardiac Fibrosis.
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DOI：
10.1161/circulationaha.118.035420
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发表时间：
2018-09-18
期刊：
影响因子：
37.8
通讯作者：
Ardehali R
中科院分区：
文献类型：
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作者：
Park S;Ranjbarvaziri S;Lay FD;Zhao P;Miller MJ;Dhaliwal JS;Huertas-Vazquez A;Wu X;Qiao R;Soffer JM;Rau C;Wang Y;Mikkola HKA;Lusis AJ;Ardehali R
遗传多样性和心脏成纤维细胞（cfb）的异质性阻碍了调节心脏纤维化的分子机制的表征。杂交小鼠多样性小组（HMDP）提供了一种有价值的工具来检查遗传多样性的心脏成纤维细胞及其在纤维化中的作用。从小鼠HMDP中选取C57BL/6J、C3H/HeJ和KK/HlJ 3个品系，通过腹腔植入渗透泵给予异丙肾上腺素（ISO）或生理盐水处理。21 d后，分别用超声心动图和三色染色法测定心功能和纤维化水平。在正常和损伤条件下，体外和体内检测CFbs的活化和增殖。对每个菌株分离的CFbs进行rna测序，采用独创性途径分析（Ingenuity Pathway Analysis， IPA）对结果进行分析，并通过逆转录qpcr、免疫组织化学和ELISA进行验证。在C57BL/6J、C3H/HeJ和KK/HlJ小鼠中，ISO治疗分别导致轻度、中度和广泛的纤维化水平（n = 7-8个心脏/条件）。用ISO处理的分离CFbs表现出菌株特异性的激活水平增加，但增殖水平相当。在体内也发现了类似的结果，成纤维细胞激活，而不是增殖，这与ISO治疗后心脏纤维化的不同水平相关。rna测序显示，每个菌株的cfb在ISO作用下表现出独特的基因表达变化。我们发现Ltbp2是ISO处理后常见的上调基因。在小鼠和人类心力衰竭患者损伤后，LTBP2的表达升高并特异性定位于心肌纤维化区域。本研究通过使用多个近交小鼠品系来表征CFbs及其对ISO治疗的反应，强调了遗传变异在心脏纤维化中的重要性。我们的数据表明，虽然成纤维细胞激活是一种与疤痕形成程度相似的反应，但增殖可能不一定与纤维化水平相关。此外，通过比较来自多个菌株的cfb，我们确定了作为潜在治疗靶点的途径，并确定了LTBP2作为纤维化标志物，与潜在心肌纤维化患者相关。
Genetic diversity and the heterogeneous nature of cardiac fibroblasts (CFbs) have hindered characterization of the molecular mechanisms that regulate cardiac fibrosis. The Hybrid Mouse Diversity Panel (HMDP) offers a valuable tool to examine genetically diverse cardiac fibroblasts and their role in fibrosis. Three strains of mice (C57BL/6J, C3H/HeJ, and KK/HlJ) were selected from the HMDP and treated with either isoproterenol (ISO) or saline by an intraperitoneally implanted osmotic pump. After 21 days, cardiac function and levels of fibrosis were measured by echocardiography and trichrome staining, respectively. Activation and proliferation of CFbs were measured by in vitro and in vivo assays under normal and injury conditions. RNA-sequencing was done on isolated CFbs from each strain and results were analyzed by Ingenuity Pathway Analysis (IPA) and validated by reverse transcription-qPCR, immunohistochemistry, and ELISA. ISO treatment in C57BL/6J, C3H/HeJ, and KK/HlJ mice resulted in minimal, moderate, and extensive levels of fibrosis, respectively (n = 7–8 hearts/condition). Isolated CFbs treated with ISO exhibited strain-specific increases in the levels of activation but showed comparable levels of proliferation. Similar results were found in vivo, with fibroblast activation, and not proliferation, correlating with the differential levels of cardiac fibrosis after ISO treatment. RNA-sequencing revealed that CFbs from each strain exhibit unique gene expression changes in response to ISO. We identified Ltbp2 as a commonly upregulated gene after ISO treatment. Expression of LTBP2 was elevated and specifically localized in the fibrotic regions of the myocardium after injury in mice and in human heart failure patients. This study highlights the importance of genetic variation in cardiac fibrosis by using multiple inbred mouse strains to characterize CFbs and their response to ISO treatment. Our data suggest that, while fibroblast activation is a response that parallels the extent of scar formation, proliferation may not necessarily correlate with levels of fibrosis. Additionally, by comparing CFbs from multiple strains, we identified pathways as potential therapeutic targets and LTBP2 as a marker for fibrosis, with relevance to patients with underlying myocardial fibrosis.