Wen F Q, Watanabe K, Tanaka H, Yoshida M
Second Department of Internal Medicine, School of Medicine, Fukuoka University, Japan.
Prostaglandins Leukot Essent Fatty Acids. 1997 Mar;56(3):185-92. doi: 10.1016/s0952-3278(97)90532-9.
We evaluated the thrombin-stimulated production of prostacyclin (PGI2) by cultured human pulmonary artery smooth muscle cells (HPASMC) that were pretreated with cytokines (IL-1 beta, TNF alpha) and lipopolysaccharide (LPS). Cultured HPASMC, obtained from autopsied cases, were identified as smooth muscle cells by immune staining with mouse anti-human alpha-smooth muscle actin monoclonal IgG. A 3 hour incubation of HPASMC with LPS, IL-1 beta, or TNF alpha followed by a 10 min exposure to 2 U/ml thrombin was sufficient to generate a greater amount of PGI2 than observed in control cells. The increase in PGI2 production peaked after 8 h in the IL-1 beta- and TNF alpha-treated HPASMC, and continued to increase for 24 h in the LPS-treated HPASMC. We then investigated the effect of incubation time of thrombin on PGI2 production in HPASMC pretreated with cytokines or LPS for 24 h. PGI2 production by LPS- and cytokine-treated HPASMC peaked after a 15 min exposure to thrombin. In contrast, the exposure of LPS- or IL-1 beta-treated HPASMC to buffer seemed to increase the release of PGI2 for up to 30 min of incubation. However, the PGI2 released was less than that in the thrombin-stimulated HPASMC. After incubation with various concentrations of LPS or cytokines, the production of PGI2 by thrombin-stimulated HPASMC showed significant, dose-dependent increases beginning at 0.1 microgram/ml of LPS, 20 U/ml of IL-1 beta, and 50 U/ml of TNF alpha. We conclude that LPS, IL-1 beta, and TNF alpha enhanced both the basal and thrombin-stimulated production of PGI2 by HPASMC. This enhanced production of PGI2 might help in lowering the pulmonary vascular tone and modifying pulmonary hemodynamics in cytokine- or endotoxin-mediated inflammation and acute injury of the lung.
我们评估了经细胞因子（IL-1β、TNFα）和脂多糖（LPS）预处理的培养人肺动脉平滑肌细胞（HPASMC）中凝血酶刺激的前列环素（PGI2）生成情况。从尸检病例中获取的培养HPASMC，通过用小鼠抗人α-平滑肌肌动蛋白单克隆IgG进行免疫染色鉴定为平滑肌细胞。将HPASMC与LPS、IL-1β或TNFα孵育3小时，随后暴露于2 U/ml凝血酶10分钟，足以产生比对照细胞中观察到的更多量的PGI2。在IL-1β和TNFα处理的HPASMC中，PGI2生成的增加在8小时后达到峰值，而在LPS处理的HPASMC中则持续增加24小时。然后，我们研究了凝血酶孵育时间对用细胞因子或LPS预处理24小时的HPASMC中PGI2生成的影响。LPS和细胞因子处理的HPASMC在暴露于凝血酶15分钟后PGI2生成达到峰值。相反，LPS或IL-1β处理的HPASMC暴露于缓冲液似乎在长达30分钟的孵育过程中增加了PGI2的释放。然而，释放的PGI2少于凝血酶刺激的HPASMC中的PGI2。在用各种浓度的LPS或细胞因子孵育后，凝血酶刺激的HPASMC中PGI2的生成从0.1微克/毫升的LPS、20 U/ml的IL-1β和50 U/ml的TNFα开始呈现显著的剂量依赖性增加。我们得出结论，LPS、IL-1β和TNFα增强了HPASMC中PGI2的基础生成和凝血酶刺激的生成。PGI2生成的这种增强可能有助于降低肺血管张力并改变细胞因子或内毒素介导的肺部炎症和急性损伤中的肺血流动力学。
