Baden Tatsuya, Yamawaki Hideyuki, Saito Kazuaki, Mukohda Masashi, Okada Muneyoshi, Hara Yukio
Department of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Higashi 23 Bancho 35-1, Towada, Aomori 034-8628, Japan.
Biochem Biophys Res Commun. 2008 Aug 22;373(2):253-7. doi: 10.1016/j.bbrc.2008.06.023. Epub 2008 Jun 17.
Methylglyoxal (MGO) is a metabolite of glucose. Since serum MGO level is increased in diabetic patients, MGO is implicated in diabetic complications related to vascular injury. We have recently demonstrated that glucose metabolite is a more powerful stimulant for endothelial cells (ECs) injury rather than glucose or advanced glycation-end products. Recent clinical trials suggest that angiotensin receptor blockers are effective to prevent diabetes-associated cardiovascular disorders beyond blood pressure lowering effect. To explore the mechanisms, we examined effects of telmisartan on MGO-induced ECs injury. Treatment of human umbilical vein ECs with MGO (560 microM) induced time-dependent (0-24 h) cell death. MGO-induced cell death was apoptosis since MGO increased cleaved caspase-3 expression. Telmisartan (0.1-10 microM) inhibited MGO-induced cell death and caspase-3 activation. These results indicate that telmisartan prevents MGO-induced apoptosis by inhibiting caspase-3 activation, which might explain at least in part the beneficial effects of telimisartan against diabetes-related cardiovascular diseases.
甲基乙二醛(MGO)是葡萄糖的一种代谢产物。由于糖尿病患者血清MGO水平升高,MGO与血管损伤相关的糖尿病并发症有关。我们最近证明,葡萄糖代谢产物对内皮细胞(ECs)损伤的刺激作用比葡萄糖或晚期糖基化终产物更强。最近的临床试验表明,血管紧张素受体阻滞剂除了具有降压作用外,还能有效预防糖尿病相关的心血管疾病。为了探究其机制,我们研究了替米沙坦对MGO诱导的ECs损伤的影响。用MGO(560微摩尔)处理人脐静脉ECs会诱导时间依赖性(0 - 24小时)细胞死亡。MGO诱导的细胞死亡是凋亡,因为MGO增加了裂解的半胱天冬酶-3的表达。替米沙坦(0.1 - 10微摩尔)抑制MGO诱导的细胞死亡和半胱天冬酶-3的激活。这些结果表明,替米沙坦通过抑制半胱天冬酶-3的激活来预防MGO诱导的凋亡,这可能至少部分解释了替米沙坦对糖尿病相关心血管疾病的有益作用。