| BackgroundCardiovascular disease arising from atherosclerosis is the leading cause of mortality and death worldwide, accounting for 16.7 million deaths each year. Atherosclerosis involving the systemic arteries, mainly involving the aortic and coronary artery and cerebral artery, renal artery and other large and medium-sized muscle elastic artery, eventually leads to their luminal stenosis or even completely blocked, making these important organ ischemia and hypoxia, dysfunction as well as the body of death. Atherosclerosis mainly influences the lining of the artery wall. Arterial endothelial cell layer is the initial site of atherosclerosis. The injury or dysfunction of endothelial cells plays an important role in atherosclerosis. Lipoprotein mainly exists in the plasma, and its function is to transport lipids of endogenous and exogenous. Low density lipoprotein(LDL) is one of the category. Low density lipoprotein(LDL) was oxidized modified forming oxidized low density lipoprotein(Ox-LDL). Ox-LDL has been convincingly implicated in the pathogenesis of atherosclerosis. Vascular endothelial injury induced by oxidized low-density lipoprotein(Ox-LDL) is one of the pathogenesis of atherosclerosis in the early stages. The lectin-like oxidised low-density lipoprotein receptor-1(LOX-1) is a vascular scavenger receptor that identified as the primary receptor for Ox-LDL uptake by endothelial cells. Conjugated linoleic acid(CLA) is a kind of unsaturated fatty acids, and is concerned for its biological activity having a protective effect on cancer, diabetes, obesity and atherosclerosis, but the specific mechanism is unclear. In this study, we examined the effects of CLA on Ox-LDL associated changes in human coronary artery endothelial cell.ObjectiveHuman coronary artery endothelial cells were cultured in vitro, and CLA was used to deal with the damage of Ox-LDL induced in HCAEC cells. The aim is to explore the effect of CLA on HCAEC damage caused by Ox-LDL and further study the role of CLA against atherosclerosis. We hope to provide some experimental basis for the prevention and treatment of atherosclerosis.MethodsWe used Ox-LDL to stimulate HCAEC cells, constructing HCAEC cell damage model. We observed the effect of conjugated linoleic acid(CLA) on the cell damage by detecting the biological function of cells, such as cell morphology, cell activity, cell proliferation, cell migration, the functional molecules eNOS and ET-1, adhesion molecule VCAM-1 and so on. We explored the protective mechanism of conjugated linoleic acid(CLA) on HCAEC cell injury induced by Ox-LDL by detecting the downstream molecules of cell damage.Results1. The viability of HCAEC cells was detected by MTT method, and the results showed that the cell activity of HCAEC decreased with the increase of Ox-LDL concentration. CLA had a reverse effect on the cell activity induced by Ox-LDL, and the effect was dose dependent.2. The results of testing NO secreted by HCAEC cells showed that HCAEC could decrease the secreted amount of NO by Ox-LDL compared with the normal control group, while the content of NO was significantly increased after CLA intervention compared with the group of Ox-LDL.3. Western Blot showed that the expression of eNOS was significantly decreased in Ox-LDL group compared with the normal control group, while the expression of eNOS in CLA+Ox-LDL group was higher than that in Ox-LDL group. It also showed that the expression of ET-1 was significantly higher in Ox-LDL group compared with the normal control group, while the expression of ET-1 in CLA+Ox-LDL group was lower than that in Ox-LDL group.4. RT-PCR and Western Blot experiment results showed that the m RNA level and the protein expression level of cell adhesion molecule VCAM-1 in Ox-LDL treatment group were significantly increased compared with that in control group and the level of m RNA and the protein expression level of VCAM-1 in CLA+ Ox-LDL group were decreased compared with the Ox-LDL treatment group.5. Cell morphology experiment showed that the cell morphology of Ox-LDL group was changed, the round cell increased, the intercellular space increased, cell shrinkaged, and the adherence was not tight compared with the normal control group, while the changes of cell morphology in the CLA +Ox-LDL group were alleviated, the intercellular space became smaller, and the morphology was tended to be normal.6. Transwell experiment and scratch test results showed that the cell migration ability of Ox-LDL treatment group was increased compared with the normal control group and the cell migration ability of CLA+Ox-LDL group was decreased compared with the Ox-LDL treatment group7. Flow cytometry and Hoechst 33258 results showed that the apoptosis rate of each treatment group was not significantly different between the treatment groups.8. Western Blot experiment results showed that the expression level of p-JNK protein in Ox-LDL group was increased compared with the control group, while the expression level of p-JNK protein in the CLA+Ox-LDL group was lower than that in the Ox-LDL treatment group.Conclusion1. CLA has a protective effect on HCAEC cell injury induced by Ox-LDL.2. CLA may protect the damage of HCAEC cells induced by Ox-LDL through JNK molecule. |
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