| Objective: Diabetes (diabetes mellitus, DM), is a group characterized by elevated blood glucose levels of chronic metabolic diseases, which major cause is insulin resistance and pancreaticβ-cell failure. Chronic poorly controlled blood glucose, as well as the ensuing high blood lipids, hypertension, may lead to heart, eyes, kidneys, feet and other organs of the complications of serious impact on people's quality of life. Oxidative stress Signaling pathway causes insulin resistance and impaired insulin secretion, mainly by oxidative damage of ROS (reactive oxygen species, ROS) and reactive nitrogen substances (reactive nitrogen species, RNS), which are the of oxygen or nitrogen-containing active products in the process of cell metabolism. They can induce tissue and cell injury through lipid peroxidation, have important physiological and pathological significance. Oxidative stress not only participates in the pathogenesis of type 2 diabetes, but also constitutes the pathogenesis of diabetes late complications. The pathological basis of diabetic vascular disease is Atherosclerosis, oxidative stress also play an important role. United Kingdom prospective studies have shown that glucose compliance lonely can not reduce the morbidity of diabetic macrovascular complications, which suggest that the initiating agent of diabetes is glucose, but not the only factor. There are other factors in the process of macroangiopathy development. Now we think that atherosclerosis is possibly caused by the arterial inflammatory diseases. Elevated blood glucose can cause endothelial cell dysfunction, apoptosis, the destruction of endothelial integrity and protective effect of the barrier disappearance, increased expression of adhesion molecules, chemokine release, leukocyte adhesion, macrophage activation, smooth muscle cell migration and proliferation,plaque finally. As a nuclear transcription factor NF-κB involved in a variety of oxidative stress, inflammatory and immune response. NF-κB can activate inducible nitric oxide synthase(iNOS), interleukin-1,6, interferon, tumor filament factor-a, vascular cell adhesion molecule-1 and intercellular adhesion molecule. NF-κB can also be cloned by adjusting its own gene and the expression level of IκB in order to achieve the purpose of self-regulation. Some scholars believe that NF-κB is one of the starting mechanism of atherosclerosis. By in situ hybridization and immunohistochemical study Linder and others found that after endothelial cells in mice injured for 45 minutes, in its damaged endothelial cells NF-κB p65 and p50 protein were significantly higher than normal, After 3 hours It was found that the VCAM-1 mRNA and protein expression increased by Northern hybridization. There are a lot of experimental studies related to NF-κB and cytokines, this study is the in vitro effect of high glucose on human umbilical vein endothelial cells(HUVEC)apoptosis and nuclear factor- kappaB(NF-κB), inducible nitric oxide synthase(iNOS), nitric oxide(NO)to explore the NF-κB-iNOS-NO in the pathogenesis of diabetic vascular disease. And we observe intervention of lipoic acid to explore the possible role and mechanism of the drug.Methods:The HUVEC cells were cultured and divided into five groups: (1) normal control group (glucose's concentration: 5.5mmol/l) (2) high glucose groups: (glucose's concentration: 25mmol/l) (3) high glucose + lipoic acid (50umol/l) group (4) high glucose + lipoic acid (100umol/l) group (5) high glucose + lipoic acid (200umol/l) group, respectively, 0h, 6h, 12h, 24h, 48h specimens from a sample for testing. The cell apoptosis rate is detected by flow cytometry, NF-κB is measured by Western Blot test, the iNOS is measured by colorimetry and the NO is measured by nitrate reduction test.Results:1 On high glucose the cell apoptosis rate and the expression of iNOS, NO are significantly increased than the control group at 6h, 12h, 24h, 48h (P <0.01). With LA intervention, 48h later, on Group A1 the apoptosis rate, the expression of iNOS and NO have no significant change with the high glucose group for 48h (P> 0.05); on Group A2, A3 the apoptosis rate, the expression of iNOS and NO are decreased than high glucose group for 48h (P<0.01), showed dose-dependent.2 On high glucose the expression of NF-κB are significantly increased, With LA intervention, NF-κB are decreased.Conclusion:1 High glucose can cause HUVEC cells apoptosis, NF-κB, iNOS, NO increased significantly, It is prompted that high glucose plays a role in human umbilical vein endothelial cells through the NF-κB-iNOS-NO pathway, and the NF-κB-iNOS-NO pathway may be associated diabetic macroangiopathy.2 High glucose can cause iNOS, NO increased significantly in early times(6h),It is prompted it possibly involve in early diabetic vascular disease.3 Lipoic Acid injection can reduce cell apoptosis, reduce the NF-κB expression, control the expression of iNOS and NO, and improve endothelial function, reduce cell damage. It is prompted lipoic acid may be reduce cell damage through NF-κB-iNOS-NO pathway, and delay high glucose toxicity on endothelial cell. It is prompted lipoic acid has the effect to prevention and treatment of diabetes and its complications, early application of lipoic acid could benefit diabetes.
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