Lee Hyun Seung, Son Seok Man, Kim Yong Ki, Hong Ki Whan, Kim Chi Dae
Department of Pharmacology and Internal Medicine, College of Medicine, Pusan National University, 10 Ami-Dong 1-Ga, Seo-Gu, Busan 602-739, South Korea.
Life Sci. 2003 May 2;72(24):2719-30. doi: 10.1016/s0024-3205(03)00186-3.
Reactive oxygen species (ROS) have been implicated in the pathogenesis of vascular dysfunction in diabetes mellitus, and NAD(P)H oxidase is known as the most important source of ROS in the vasculatures. To determine whether NAD(P)H oxidase is a major participant in the critical intermediary signaling events in high glucose (HG, 25 mM)-induced proliferation of vascular smooth muscle cells (VSMC), we investigated in explanted aortic VSMC from rats the role of NAD(P)H oxidase on the HG-related cellular proliferation and superoxide production. VSMC under HG condition had increased proliferative capacity that was inhibited by tiron (1 mM), a cell membrane permeable superoxide scavenger, but not by SOD, which is not permeable to cell membrane. The nitroblue tetrazolium staining in the HG-exposed VSMC was more prominent than that of VSMC under normal glucose (5.5 mM) condition, which was significantly inhibited by DPI (10 microM), an NAD(P)H oxidase inhibitor, but not by inhibitors for other oxidases such as NADH dehydrogenase, xanthine oxidase, and nitric oxide synthase. In the VSMC under HG condition, the enhanced NAD(P)H oxidase activity with increased membrane translocation of Rac1 was observed, but the protein expression of p22phox and gp91phox was not increased. These data suggest that HG-induced changes in VSMC proliferation are related to the intracellular production of superoxide through enhanced activity of NAD(P)H oxidase.
活性氧（ROS）与糖尿病血管功能障碍的发病机制有关，而NAD（P）H氧化酶是血管系统中ROS的最重要来源。为了确定NAD（P）H氧化酶是否是高糖（HG，25 mM）诱导的血管平滑肌细胞（VSMC）增殖关键中间信号事件的主要参与者，我们研究了大鼠离体主动脉VSMC中NAD（P）H氧化酶对HG相关细胞增殖和超氧化物产生的作用。HG条件下的VSMC增殖能力增强，可被细胞膜可渗透的超氧化物清除剂替诺（1 mM）抑制，但不能被细胞膜不可渗透的超氧化物歧化酶（SOD）抑制。暴露于HG的VSMC中的硝基蓝四氮唑染色比正常葡萄糖（5.5 mM）条件下的VSMC更明显，这被NAD（P）H氧化酶抑制剂二苯基碘（DPI，10 microM）显著抑制，但不被其他氧化酶如NADH脱氢酶、黄嘌呤氧化酶和一氧化氮合酶的抑制剂抑制。在HG条件下的VSMC中，观察到NAD（P）H氧化酶活性增强，Rac1的膜转位增加，但p22phox和gp91phox的蛋白表达未增加。这些数据表明，HG诱导的VSMC增殖变化与通过增强NAD（P）H氧化酶活性导致的细胞内超氧化物产生有关。
