Quagliaro Lisa, Piconi Ludovica, Assaloni Roberta, Da Ros Roberto, Szabó Csaba, Ceriello Antonio
Morpurgo-Hofman Research Laboratory on Aging, Udine, Italy.
Nutr Metab Cardiovasc Dis. 2007 May;17(4):257-67. doi: 10.1016/j.numecd.2006.01.007. Epub 2006 Aug 4.
The aim of the study was to elucidate the chain of events leading to oxidative damage in endothelial cells exposed to high glucose.
The nitric oxide synthase (NOS) cofactor tetrahydrobiopterin (BH4), the peroxynitrite decomposition catalyst FP15, the inhibitor of mitochondrial complex II thenoyltrifluoroacetone (TTFA) and the antioxidant superoxide dismutase (SOD) mimetic Mn(III)tetrakis(4-benzoic acid) porphyrin chloride (MnTBAP) were individually added to human umbilical vein endothelial cells (HUVEC) cultured in high glucose. This study was designed to establish the possible sequence of action of NOS, peroxynitrite and superoxide anion in the oxidative damage cascade.
We found that in high glucose, nitrotyrosine, 8OHdG, NO (+40%) and O2- (+300%) production, eNOS and caspase-3 expression increased, while Bcl-2 expression decreased. MnTBAP and TTFA were able to normalize all the parameters assayed. FP15 caused an increase in NO production, did not interfere with eNOS expression and O2- generation, but was able to reduce apoptosis and to normalize nitrotyrosine and 8OHdG formation. BH4 enrichment was able to reduce O2- generation, nitrotyrosine and 8OHdG formation and apoptosis. The addition of this cofactor did not affect eNOS expression, but increased NO formation, more than FP15.
These data show the starting role of superoxide anion generated at mitochondrial level in the cascade of events leading to hyperglycemia generated apoptosis.
本研究旨在阐明高糖环境下内皮细胞发生氧化损伤的一系列事件。
将一氧化氮合酶（NOS）辅因子四氢生物蝶呤（BH4）、过氧亚硝酸根分解催化剂FP15、线粒体复合物II抑制剂噻吩甲酰三氟丙酮（TTFA）以及抗氧化剂超氧化物歧化酶（SOD）模拟物四（对苯甲酸）锰（III）卟啉氯化物（MnTBAP）分别添加到在高糖环境中培养的人脐静脉内皮细胞（HUVEC）中。本研究旨在确定NOS、过氧亚硝酸根和超氧阴离子在氧化损伤级联反应中可能的作用顺序。
我们发现，在高糖环境中，硝基酪氨酸、8-羟基脱氧鸟苷（8OHdG）、NO（增加40%）和O₂⁻（增加300%）的生成、内皮型一氧化氮合酶（eNOS）和半胱天冬酶-3的表达增加，而Bcl-2表达降低。MnTBAP和TTFA能够使所有检测参数恢复正常。FP15导致NO生成增加，不干扰eNOS表达和O₂⁻生成，但能够减少细胞凋亡，并使硝基酪氨酸和8OHdG的形成恢复正常。BH4富集能够减少O₂⁻生成、硝基酪氨酸和8OHdG的形成以及细胞凋亡。添加该辅因子不影响eNOS表达，但增加NO生成，且增加幅度超过FP15。
这些数据表明，线粒体水平产生的超氧阴离子在导致高血糖诱导细胞凋亡的一系列事件中起起始作用。
