| With economic conditions improving, lifestyle changing and population ageing, the prevalence of diabetes has risen greatly in China. It's 2.51 per cent in China in 1997 and will be to 14 per cent in 2010. Epidemiologic studies have suggested that the diabetic has a substantially greater risk for development of atherosclerosis. Coronary heart disease, cerebrovasculartdisease and peripheral vascular disease are far more frequent in diabetic than in the nondiabetic population. Not only is in cardiovascular disease in diabetes more frequent, but onset at earlier age, and exhibiting a greater tendency toward diffuse and serious lesion. Cardiovascular disease has been the major cause of disablement and death in patients with diabetes. The etiology of the accelerated atherosclerosis in diabetesis probably multifactorial and incompletely understood. It has been shown that lipoprotein lipase (LPL) activity is low in normal arteries, which have few macrophages, and increases during progression of the atherosclerotic plague, which contains a large number of macrophages-like cells. Macrophages constitutively synthesize LPL, which may contribute to lipid accumulation within the arterial wall, promoting the atherogenic process.Peroxisome proliferator-activated receptors (PPARs) are members of the superfamily of nuclear hormone receptors, including PPARa ,PPARB and PPAR y. PPAR bind to a specific peroxisome proliferator responsive element (PPRE) in the promoter of target genes (such as LPL), thus regulating the transcription of these genes. PPARY are involved in adipocyte differentiation, obesity and insulin insistence, and the antidiabetic glitazones (such as pioglitazone) are high-affinity ligands. So, these attracted more and more people' s attentions.Despite the high incidence of atherosclerosis in diabetic patients and the potential key role of macrophage LPL in the atherogenic process, gene expression of macrophage LPL in patients with type 2 diabetes and regulation of macrophage LPLexpression has few investigated. Along with LPL, TNF-a may represent a major factor contributing to the development of atheroscleosis in type 2 diabetes. In present study, we studied gene expression of macrophage LPL and PPAR y in type 2 diabetes and regulation by pioglitazone . Serum TNF-a in type 2 diabetes before and after treatment with pioglitazone was also determined.The study group comprised 47 patients with type 2 diabetes and 28 controls, matched with patients for sex, age, and body mass index. All patients recruited from our outpatient clinic, 36 of them were treated with sulfonylureas and metformin, and the other 11 with sulfonylureas, metformin and pioglitazone.Human monocytes were freshly isolated as previously described, which were assessed by flow cytometry and immunohistochemistry method, using anti-CD14 monoclonal antibody. These were differentiated into macrophages in RPMI 1640 medium supplemented with 20% (vol/vol) autologous serum. After 4 days in culture, total RNA was extracted from human macrophages with TRIzol reagent. cDNA was obtained from total RNA using a reverse transcription reaction. The cDNA obtained was amplified by using three synthetic primers specific for human LPL (5'-CTGCAAATGAGACACTTTCTC-3' and 5'-GAGATTTCTCTGTATGGCACC-3'), human PPAR y (5'-TCTCTCCGTAATGGAAGACC-3' and 5'-GCATTATGAGACATCCCCAC-3') and human B-actin(5'-TCGACAA CGGCTCCGGCA-3'and 5'-CGTACATGGCTGGGGTGT-3') as internal standard in PCR reaction mixture. 277bp LPL cDNA fragment, 474bp PPARr cDNA fragment, and 370bp B -actin cDNA fragment were amplified enzymatic ally by repeated cycles. An aliguot of each reaction mixture was then subjected to electrophoresis on 1. 2% agarose gel, and the bands, which had been confirmed by directly sequencing after molecular cloning with pGEM-T and pGEM-T Easy Vector Systems, were measured by Kodak digital-science system DC-40. Serum TNF-a was determined by a double sandwich ELISA.The results showed that macrophages of diabetic patients were a significant increase in L...
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