Yerneni K K, Bai W, Khan B V, Medford R M, Natarajan R
Department of Diabetes and Endocrinology, City of Hope National Medical Center, Duarte, California 91010-3000, USA.
Diabetes. 1999 Apr;48(4):855-64. doi: 10.2337/diabetes.48.4.855.
The transcriptional nuclear factor (NF)-kappaB can be activated by diverse stimuli such as cytokines, mitogens, oxidative stress, and lipids, leading to the transactivation of several genes that play important roles in the development of atherosclerosis. Because oxidative stress may play a key role in the pathogenesis of diabetic vascular disease, we have examined whether culture of porcine vascular smooth muscle cells (PVSMCs) under high glucose (HG) conditions (25 mmol/l) to simulate the diabetic state can lead to the activation of NF-kappaB, and also whether cytokine- or growth factor-induced NF-kappaB activation is altered by HG culture. We observed that PVSMCs cultured in HG showed significantly greater activation of NF-kappaB in the basal state compared with cells cultured in normal glucose (NG) (5.5 mmol/l). Treatment of the cells with cytokines, such as tumor necrosis factor (TNF)-alpha and interleukin-1beta, or with growth factors, such as platelet-derived growth factor, insulin-like growth factor-I, and epidermal growth factor, all led to NF-kappaB activation in cells cultured in both NG and HG. However, their effects were markedly greater in HG. The augmented TNF-alpha-induced NF-kappaB activation in HG was associated with increased TNF-alpha-mediated transcriptional activation of the vascular cell adhesion molecule-1 promoter. Immunoblotting with an antibody to the p65 subunit of NF-kappaB indicated that the levels of this protein were higher in the nuclear extracts from cells cultured in HG compared with NG. Cells cultured in HG also produced significantly greater amounts of the reactive oxygen species superoxide. HG-induced NF-kappaB activation was inhibited by a protein kinase C inhibitor, calphostin C. These results suggest that hyperglycemia-induced activation of NF-kappaB in VSMCs may be a key mechanism for the accelerated vascular disease observed in diabetes.
转录核因子（NF）-κB可被多种刺激激活，如细胞因子、丝裂原、氧化应激和脂质，从而导致多个在动脉粥样硬化发展中起重要作用的基因的反式激活。由于氧化应激可能在糖尿病血管疾病的发病机制中起关键作用，我们研究了在高糖（HG，25 mmol/l）条件下培养猪血管平滑肌细胞（PVSMC）以模拟糖尿病状态是否会导致NF-κB激活，以及细胞因子或生长因子诱导的NF-κB激活是否会因HG培养而改变。我们观察到，与在正常葡萄糖（NG，5.5 mmol/l）中培养的细胞相比，在HG中培养的PVSMC在基础状态下NF-κB的激活明显更强。用细胞因子如肿瘤坏死因子（TNF）-α和白细胞介素-1β或生长因子如血小板衍生生长因子、胰岛素样生长因子-I和表皮生长因子处理细胞，均导致在NG和HG中培养的细胞发生NF-κB激活。然而，它们的作用在HG中明显更强。HG中TNF-α诱导的NF-κB激活增强与TNF-α介导的血管细胞黏附分子-1启动子的转录激活增加有关。用针对NF-κB p65亚基的抗体进行免疫印迹表明，与NG相比，HG中培养的细胞的核提取物中该蛋白的水平更高。在HG中培养的细胞还产生了明显更多的活性氧超氧化物。HG诱导的NF-κB激活被蛋白激酶C抑制剂钙泊三醇C抑制。这些结果表明，高血糖诱导的VSMC中NF-κB激活可能是糖尿病中观察到的血管疾病加速发展的关键机制。
