Division of Cardiothoracic Surgery, Department of Surgery, Medical University of South Carolina, and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29425, USA.
J Thorac Cardiovasc Surg. 2010 Sep;140(3):653-9. doi: 10.1016/j.jtcvs.2009.12.033. Epub 2010 Mar 9.
Thoracic aortic aneurysms result from dysregulated remodeling of the vascular extracellular matrix, which may occur as a result of altered resident cellular function. The present study tested the hypothesis that aortic fibroblasts undergo a stable change in cellular phenotype during thoracic aortic aneurysm formation.
Primary murine aortic fibroblasts were isolated from normal and thoracic aortic aneurysm-induced aortas (4 weeks post induction with 0.5 mol/L CaCl(2) 15 minutes) by the outgrowth method. Normal and thoracic aortic aneurysm cultures were examined using a focused polymerase chain reaction array to determine fibroblast-specific changes in gene expression in the absence and presence of biological stimulation (endothelin-1, phorbol-12-myristate-13-acetate, angiotensin-II). The relative expression of 38 genes, normalized to 4 housekeeping genes, was determined, and genes displaying a minimum 2-fold increase/decrease or genes with significantly different normalized cycle threshold values were considered to have altered expression.
At steady state, thoracic aortic aneurysm fibroblasts revealed elevated expression of several matrix metalloproteinases (Mmp2, Mmp11, Mmp14), collagen genes/elastin (Col1a1, Col1a2, Col3a1, Eln), and other matrix proteins, as well as decreased expression of Mmp3, Timp3, and Ltbp1. Moreover, gene expression profiles in thoracic aortic aneurysm fibroblasts were different than normal fibroblasts after equivalent biological stimuli.
This study demonstrated for the first time that isolated primary aortic fibroblasts from thoracic aortic aneurysm-induced mice possess a unique and stable gene expression profile, and when challenged with biological stimuli, induce a transcriptional response that is different from normal aortic fibroblasts. Together, these data suggest that aortic fibroblasts undergo a stable phenotypic change during thoracic aortic aneurysm development, which may drive the enhancement of extracellular matrix proteolysis in thoracic aortic aneurysm progression.
胸主动脉瘤是由于血管细胞外基质的失调重塑导致的，这可能是由于细胞功能的改变所致。本研究通过检测假设，即在胸主动脉瘤形成过程中，主动脉成纤维细胞的细胞表型发生稳定改变。
采用体外细胞培养的方法，从正常和胸主动脉瘤诱导的（0.5mol/L CaCl2 15 分钟诱导 4 周后）小鼠主动脉中分离出原代主动脉成纤维细胞。通过聚焦聚合酶链反应阵列检测正常和胸主动脉瘤培养物，以确定在没有和存在生物刺激（内皮素-1、佛波醇-12-肉豆蔻酸-13-乙酸酯、血管紧张素-II）时，成纤维细胞特异性基因表达的变化。以 4 个管家基因标准化后，确定 38 个基因的相对表达量，将表达量增加/减少至少 2 倍或标准化循环阈值值显著不同的基因视为表达发生改变。
在稳定状态下，胸主动脉瘤成纤维细胞表现出几种基质金属蛋白酶（Mmp2、Mmp11、Mmp14）、胶原基因/弹性蛋白（Col1a1、Col1a2、Col3a1、Eln）和其他基质蛋白的表达升高，以及 Mmp3、Timp3 和 Ltbp1 的表达降低。此外，与正常成纤维细胞相比，胸主动脉瘤成纤维细胞在接受相同的生物刺激后的基因表达谱不同。
本研究首次证明，从胸主动脉瘤诱导的小鼠分离的原代主动脉成纤维细胞具有独特且稳定的基因表达谱，并且在受到生物刺激时，会引起与正常主动脉成纤维细胞不同的转录反应。综上所述，这些数据表明，在胸主动脉瘤发展过程中，主动脉成纤维细胞发生稳定的表型改变，这可能推动胸主动脉瘤进展中外基质蛋白水解的增强。
