Quagliaro Lisa, Piconi Ludovica, Assaloni Roberta, Da Ros Roberto, Maier Amabile, Zuodar Gianni, Ceriello Antonio
Morpurgo-Hofman Research Laboratory on Aging, Udine, Italy.
Atherosclerosis. 2005 Dec;183(2):259-67. doi: 10.1016/j.atherosclerosis.2005.03.015.
In this study the effects of stable and intermittent high glucose concentrations on ICAM-1, VCAM-1 and E-selectin production, PKC activity and PKCbetaI, betaII and delta isoforms expression in cultured HUVEC have been examined. In stable high glucose ICAM-1, VCAM-1 and E-selectin concentration and mRNA expression increased, and this effect was even more evident in intermittent high glucose. PKC activity increased in fluctuating glucose compared to stable high glucose, due to an over-expression of betaI, betaII and delta isoforms. ICAM-1, VCAM-1 and E-selectin, after the adding of total PKC inhibitor bisindolylmaleimide-I (BIMI-I) and LY379196, a specific inhibitor of PKCbeta, were equally reduced. 8-Hydroxydeoxyguanosine (8-OHdG), a sensitive indicator of oxidative damage to DNA, increased in stable and even more in intermittent high glucose and was reduced by both BIMI-I and LY379196. However, when thenoyltrifluoroacetone (TTFA), an inhibitor of mitochondrial complex II and the SOD mimetic Mn(III)tetrakis(4-benzoic acid) porphyrin chloride (MnTBAP) were added, all adhesion molecules, any PKC isoforms expression and 8-hydroxydeoxyguanosine were normalized in both constant and oscillating glucose. In conclusion intermittent high glucose induces a greater expression of the adhesion molecules than stable high glucose; this effect seems to be related to an activation of PKCbeta, but completely dependent from mitochondrial free radicals over-production.
在本研究中，已检测了稳定和间歇性高葡萄糖浓度对培养的人脐静脉内皮细胞（HUVEC）中细胞间黏附分子-1（ICAM-1）、血管细胞黏附分子-1（VCAM-1）和E-选择素产生、蛋白激酶C（PKC）活性以及PKCβI、βII和δ亚型表达的影响。在稳定高葡萄糖环境下，ICAM-1、VCAM-1和E-选择素浓度及mRNA表达增加，而在间歇性高葡萄糖环境下这种效应更为明显。与稳定高葡萄糖相比，波动葡萄糖环境下PKC活性增加，这是由于βI、βII和δ亚型的过度表达。加入总PKC抑制剂双吲哚马来酰胺-I（BIMI-I）和PKCβ特异性抑制剂LY379196后，ICAM-1、VCAM-1和E-选择素均同等程度降低。8-羟基脱氧鸟苷（8-OHdG）是DNA氧化损伤的敏感指标，在稳定高葡萄糖环境下增加，在间歇性高葡萄糖环境下增加得更多，且被BIMI-I和LY379196均降低。然而，当加入线粒体复合物II抑制剂噻吩甲酰三氟丙酮（TTFA）和超氧化物歧化酶模拟物四（4-苯甲酸）锰（III）卟啉氯化物（MnTBAP）时，在恒定和振荡葡萄糖环境下，所有黏附分子、任何PKC亚型表达以及8-羟基脱氧鸟苷均恢复正常。总之，间歇性高葡萄糖比稳定高葡萄糖诱导黏附分子表达增加更多；这种效应似乎与PKCβ的激活有关，但完全依赖于线粒体自由基的过量产生。
