Hyperlipidemia induces vascular smooth muscle cell proliferation involving Wnt/ß-catenin signaling.

Hyperlipidemia has been shown to stimulate vascular smooth muscle cell (VSMC) proliferation. Wnt signaling pathway plays a critical role in embryonic development and cell proliferation. In this study, Sprague-Dawley rats fed with high-fat or normal diet for 12 weeks were sacrificed, and the thoracic aorta was harvested to determine wnt3a, ß-catenin, T-cell factor 4 (TCF4), and cyclin D1 expressions. VSMC proliferation within thoracic aorta and lipid accumulation within VSMCs were detected. Rat aortic VSMCs were cultured in serum from rats with hyperlipidemia or DKK-1; Wnt3a, ß-catenin, TCF4, and cyclin D1 expressions, and cell cycle distribution were determined. The findings demonstrated that increased number of VSMCs, lipid droplets, and vacuoles within thoracic aorta in the high-fat-fed group. Compared with controls, VSMCs from high-fat-fed rats showed higher mRNA expressions of wnt3a, ß-catenin, TCF4, and cyclin D1, as well as in VSMCs cultured with hyperlipidemic serum. After 24 h, VSMCs stimulated with hyperlipidemic serum showed significantly increased cell number and S-phase entry compared with cells exposed to normolipidemic serum. These effects were blocked by DKK-1. These results suggest that Wnt/ß-catenin signaling plays an important role in hyperlipidemia-induced VSMC proliferation.

Early outcomes of isolated coronary artery bypass grafting in Chinese aged patients with diabetes mellitus.

OBJECTIVE: To compare the early outcomes of coronary artery bypass grafting (CABG) in aged diabetic patients, and evaluate the affection of diabetes on the early outcomes of CABG in aged patients. METHODS: The study took place in the Department of Cardiovascular Surgery, Shanghai Jiao Tong University Affiliated First People's Hospital, Shanghai, China, between January 2000 and July 2008. Five hundred and ninety-three elderly patients (age > or = 70-years-old), undergoing isolated CABG were retrospectively divided into diabetic group and non-diabetic group. We analyzed the pre-operative, intra-operative, and post-operative variables of the 2 groups. The t-test, Chi-square test, and multivariate logistic regression were used to determine the differences between the 2 groups of patients. RESULTS: There was no statistical difference of pre-operative and intraoperative variables between the 2 groups, except that there were more left main coronary artery diseases in the diabetic group. Values in the post-operative period such as morbidity, complications, and blood infusion had no differences between the 2 groups. Diabetes mellitus and age are not the risk factors for in-hospital mortality. CONCLUSION: Coronary artery bypass grafting in elderly patients is plausible. Furthermore, diabetic patients could get the same surgical results as those non-diabetic patients.