Rizvi M A, Myers P R
Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA.
J Mol Cell Cardiol. 1997 Jul;29(7):1779-89. doi: 10.1006/jmcc.1996.0480.
The mechanisms governing the pathological accumulation of collagen in the extracellular matrix following angioplasty are complex, but may involve interactions between endothelium-derived paracrine agents and vascular cellular components. We tested the hypothesis that nitric oxide (NO) directly decreases collagen levels and decreases endothelin (ET-1)-stimulated increases in levels of specific collagen subtypes in coronary vascular smooth muscle cells (VSMC). Cultured VSMC were incubated for 48 h with the NO donor CAS 754 (10(-4) M), ET-1 (10(-8) M), or ET-1 plus CAS 754. In some experiments, angiotensin II (Ang II; 10(-8) M) was utilized in place of ET-1. Soluble collagen types I and III were quantitated with an ELISA method, and cell counts were performed. CAS 754 significantly inhibited cell proliferation (-17+/-2% v control), basal total protein synthesis (-65+/-7% v control), and basal collagen type I levels (-39+/-6% v control), but not collagen type III levels. ET-1 and Ang II both significantly stimulated cell proliferation (26+/-5% v control), total protein synthesis (169+/-6% v control), and collagen type I levels (200+/-11% v control). Ang II, but not ET-1, significantly increased collagen type III levels. Co-incubations of ET-1 and CAS 754 resulted in a significant decrease in cell proliferation, protein synthesis, and collagen levels (-23+/-2% v control, 90+/-5% v control, and 63+/-3% v control, respectively) compared to ET-1 alone. In contrast, co-incubation of Ang II and CAS 754 had no significant effect on cell proliferation, protein synthesis, and collagen levels seen with Ang II alone. These results demonstrate that NO inhibits basal collagen levels and cell division. Additionally, NO alters ET-1 stimulation of VSMC proliferation, protein synthesis, and production of extracellular matrix components. Thus, an imbalance in key endothelium-derived compounds could significantly impact upon extracellular matrix deposition following mechanical revascularization.
血管成形术后细胞外基质中胶原蛋白病理性积聚的调控机制很复杂，但可能涉及内皮源性旁分泌因子与血管细胞成分之间的相互作用。我们检验了这样一个假设：一氧化氮（NO）可直接降低胶原蛋白水平，并降低内皮素（ET-1）刺激引起的冠状动脉血管平滑肌细胞（VSMC）中特定胶原蛋白亚型水平的升高。将培养的VSMC与NO供体CAS 754（10⁻⁴ M）、ET-1（10⁻⁸ M）或ET-1加CAS 754一起孵育48小时。在一些实验中，使用血管紧张素II（Ang II；10⁻⁸ M）代替ET-1。用ELISA方法对可溶性I型和III型胶原蛋白进行定量，并进行细胞计数。CAS 754显著抑制细胞增殖（与对照组相比为-17±2%）、基础总蛋白合成（与对照组相比为-65±7%）和基础I型胶原蛋白水平（与对照组相比为-39±6%），但不影响III型胶原蛋白水平。ET-1和Ang II均显著刺激细胞增殖（与对照组相比为26±5%）、总蛋白合成（与对照组相比为169±6%）和I型胶原蛋白水平（与对照组相比为200±11%）。Ang II显著增加III型胶原蛋白水平，但ET-1无此作用。与单独使用ET-1相比，ET-1与CAS 754共同孵育导致细胞增殖、蛋白合成和胶原蛋白水平显著降低（分别为与对照组相比-23±2%、90±5%和63±3%）。相反，Ang II与CAS 754共同孵育对单独使用Ang II时的细胞增殖、蛋白合成和胶原蛋白水平无显著影响。这些结果表明，NO可抑制基础胶原蛋白水平和细胞分裂。此外，NO可改变ET-1对VSMC增殖、蛋白合成和细胞外基质成分产生的刺激作用。因此，关键内皮源性化合物的失衡可能会对机械性血运重建后的细胞外基质沉积产生重大影响。
