Lan Kuo-Cheng, Chiu Chen-Yuan, Kao Chia-Wei, Huang Kuo-How, Wang Ching-Chia, Huang Kuo-Tong, Tsai Keh-Sung, Sheu Meei-Ling, Liu Shing Hwa
Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.
PLoS One. 2015 Apr 21;10(4):e0124418. doi: 10.1371/journal.pone.0124418. eCollection 2015.
Microvascular complications eventually affect nearly all patients with diabetes. Advanced glycation end-products (AGEs) resulting from hyperglycemia are a complex and heterogeneous group of compounds that accumulate in the plasma and tissues in diabetic patients. They are responsible for both endothelial dysfunction and diabetic vasculopathy. The aim of this study was to investigate the cytotoxicity of AGEs on pancreatic islet microvascular endothelial cells. The mechanism underlying the apoptotic effect of AGEs in pancreatic islet endothelial cell line MS1 was explored. The results showed that AGEs significantly decreased MS1 cell viability and induced MS1 cell apoptosis in a dose-dependent manner. AGEs dose-dependently increased the expressions of cleaved caspase-3, and cleaved poly (ADP-ribose) polymerase in MS1 cells. Treatment of MS1 cells with AGEs also resulted in increased nuclear factor (NF)-κB-p65 phosphorylation and cyclooxygenase (COX)-2 expression. However, AGEs did not affect the expressions of endoplasmic reticulum (ER) stress-related molecules in MS1 cells. Pretreatment with NS398 (a COX-2 inhibitor) to inhibit prostaglandin E2 (PGE2) production reversed the induction of cleaved caspase-3, cleaved PARP, and MS1 cell viability. Moreover, AGEs significantly increased the receptor for AGEs (RAGE) protein expression in MS1 cells, which could be reversed by RAGE neutralizing antibody. RAGE Neutralizing antibody could also reverse the induction of cleaved caspase-3 and cleaved PARP and decreased cell viability induced by AGEs. These results implicate the involvement of NF-κB-activated COX-2/PGE2 up-regulation in AGEs/RAGE-induced islet endothelial cell apoptosis and cytotoxicity. These findings may provide insight into the pathological processes within the pancreatic islet microvasculature induced by AGEs accumulation.
微血管并发症最终几乎会影响所有糖尿病患者。高血糖产生的晚期糖基化终产物(AGEs)是一组复杂且异质的化合物,在糖尿病患者的血浆和组织中蓄积。它们既导致内皮功能障碍,也引发糖尿病性血管病变。本研究的目的是探究AGEs对胰岛微血管内皮细胞的细胞毒性。探讨了AGEs在胰岛内皮细胞系MS1中诱导凋亡作用的潜在机制。结果显示,AGEs显著降低MS1细胞活力,并以剂量依赖方式诱导MS1细胞凋亡。AGEs剂量依赖性地增加MS1细胞中裂解的半胱天冬酶-3和裂解的聚(ADP-核糖)聚合酶的表达。用AGEs处理MS1细胞还导致核因子(NF)-κB-p65磷酸化增加和环氧化酶(COX)-2表达增加。然而,AGEs不影响MS1细胞中内质网(ER)应激相关分子的表达。用NS398(一种COX-2抑制剂)预处理以抑制前列腺素E2(PGE2)生成,可逆转裂解的半胱天冬酶-3、裂解的PARP的诱导以及MS1细胞活力。此外,AGEs显著增加MS1细胞中AGEs受体(RAGE)蛋白表达,这可被RAGE中和抗体逆转。RAGE中和抗体也可逆转AGEs诱导的裂解的半胱天冬酶-3和裂解的PARP,并降低细胞活力。这些结果表明NF-κB激活的COX-2/PGE2上调参与了AGEs/RAGE诱导的胰岛内皮细胞凋亡和细胞毒性。这些发现可能为AGEs蓄积诱导的胰岛微血管内病理过程提供见解。