Regression of hypertrophied rat pulmonary arteries in organ culture is associated with suppression of proteolytic activity, inhibition of tenascin-C, and smooth muscle cell apoptosis
Regression of hypertrophied rat pulmonary arteries in organ culture is associated with suppression of proteolytic activity, inhibition of tenascin-C, and smooth muscle cell apoptosis
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DOI：
10.1161/01.res.84.10.1223
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发表时间：
1999-05-28
影响因子：
20.1
通讯作者：
Rabinovitch, M
中科院分区：
文献类型：
--
作者：
Cowan, KN;Jones, PL;Rabinovitch, M
肺血管疾病的特点是弹性蛋白酶活性升高和基质糖蛋白TN的沉积，并与增殖的平滑肌细胞(SMCs)共存。在培养的肺动脉(PA)SMC中，TN受到基质金属蛋白酶(MMPs)和机械应力的调节。在贴壁的胶原凝胶上，MMPs上调TN，导致SMC增殖，而在漂浮的胶原上，减少的MMPs抑制TN，诱导SMC凋亡。我们通过比较正常的幼猪和肥厚的大鼠PAS在胶原凝胶中包埋8天的贴壁和漂浮状态，观察全血管内SMC的反应。正常猪PAS在胶原凝胶中的特征是酶谱检测到的基质金属蛋白酶-2和基质金属蛋白酶-9的活性增加，免疫印迹和免疫反应密度分析检测到TN的沉积。漂浮胶原上的PAS显示MMPs活性降低，TN沉积减少。末端脱氧核苷酸转移酶介导的缺口末端标记法显示，Tn富集区与增殖细胞核抗原免疫反应相关，TN贫乏区与细胞凋亡相关，但壁厚差异无统计学意义。虽然正常的大鼠PA类似于仔猪血管，但肥大的大鼠PA表现出放大的反应。弹性蛋白酶、MMP2、TN和弹性蛋白沉积增加，SMC增殖细胞核抗原阳性，与附着胶原进行性中层增厚有关，而MMP2、弹性蛋白酶、TN减少和诱导SMC凋亡伴随着漂浮胶原增厚的消退。我们的研究表明，完整血管中肥大的SMC可以被凋亡，细胞外基质的再吸收可以通过抑制弹性蛋白酶和MMPs来实现，我们的研究提出了逆转血管疾病的新策略。
Increased elastase activity and deposition of the matrix glycoprotein tenascin-C (TN), codistributing with proliferating smooth muscle cells (SMCs), are features of pulmonary vascular disease. In pulmonary artery (PA) SMC cultures, TN is regulated by matrix metalloproteinases (MMPs) and mechanical stress. On attached collagen gels, MMPs upregulate TN, leading to SMC proliferation, whereas on floating collagen, reduced MMPs suppress TN and induce SMC apoptosis, We now investigate the response of SMCs in the whole vessel by comparing attached and floating conditions using either normal PAs derived from juvenile pigs or normal or hypertrophied rat PAs that were embedded in collagen gels for 8 days. Normal porcine PAs in attached collagen gels were characterized by increasing activity of MMP-2 and MMP-9 assessed by zymography and TN deposition detected by Western immunoblotting and densitometric analysis of immunoreactivity. PAs on floating collagen showed reduced activity of both MMPs and deposition of TN. Tenascin-rich foci were associated with proliferating cell nuclear antigen immunoreactivity, and TN-poor areas with apoptosis, by terminal deoxynucleotidyl transferase-mediated nick end labeling assay, but no difference in wall thickness was observed. Although normal rat PAs were similar to piglet vessels, hypertrophied rat PAs showed an amplified response. Increased elastase, MMP-2, TN, and elastin deposition, as well as SMC proliferating cell nuclear antigen positivity, correlated with progressive medial thickening on attached collagen, whereas reduced MMP-2, elastase, TN, and induction of SMC apoptosis accompanied regression of the thickened media on floating collagen. In showing that hypertrophied SMCs in the intact vessel can be made to apoptose and that resorption of extracellular matrix can be achieved by inhibition of elastase and MMPs, our study suggests novel strategies to reverse vascular disease.