Impact of the interaction between the polymorphisms and hypermethylation of the CD36 gene on a new biomarker of type 2 diabetes mellitus: circulating soluble CD36 (sCD36) in Senegalese females.

BACKGROUND: Several predisposing factors for diabetes mellitus have been identified, including cluster determinant 36 (CD36) receptor expression. We aimed to determine the effects of CD36 gene polymorphisms and hypermethylation on the plasma CD36 protein levels in type 2 diabetes. MATERIALS AND METHODS: We conducted a cross-sectional study involving 100 females (lean healthy control subjects and subjects with type 2 diabetes). This study was conducted at the Human Physiology Laboratory at the Dakar Faculty of Medicine in Senegal. Circulating sCD36 levels and DNA methyltransferase 3a levels were determined by enzyme-linked immunosorbent assay. The other biological parameters were evaluated in a biochemical laboratory. CD36 gene polymorphisms and methylation were explored by real-time polymerase chain reaction and methylation-specific polymerase chain reaction, respectively. RESULTS: sCD36 was negatively correlated with HDL-cholesterol levels (r = - 0.52 p = 0.0001) and triglyceride levels (r = - 0.36 p = 0.01) in control subjects. However, in the type 2 diabetes group, sCD36 levels were positively correlated with total cholesterol levels (r = 0.28 p = 0.04). For rs3211867, control subjects harboring the CC genotypes had significantly higher sCD36 levels than control subjects harboring the AA/AC genotype (p = 0.02); in the type 2 diabetes group, the sCD36 level was not significantly lower in subjects harboring the AA/AC genotype than in subjects harboring the CC genotype (p = 0.27). CD36 gene methylation reduced the sCD36 level in the control subjects compared to control subjects without CD36 gene methylation (p = 0.03). This difference was not significant in the type 2 diabetes group comparing subjects with diabetes with CD36 gene methylation to subjects with diabetes without CD36 gene methylation (p = 0.09). We noted a nonsignificant increase in sCD36 levels in subjects with diabetes with CD36 gene methylation compared to control subjects with CD36 gene methylation (p = 0.27). A combination of the CD36 polymorphism effect and the CD36 methylation effect did not significantly reduce sCD36 levels in subjects with type 2 diabetes. CONCLUSION: CD36 gene polymorphisms and CD36 gene methylation separately reduce sCD36 levels. Their impacts are compensated for in subjects with type 2 diabetes by an increase in sCD36 levels, the mechanism of which needs to be elucidated.

Role of AMP-activated Protein Kinase in NO- and EDHF-mediated Endothelium-dependent Relaxations to Red Wine Polyphenols.

BACKGROUND: Several epidemiological studies have shown that regular consumption of moderate amounts of wine, in particular red wine, is associated with a decreased total mortality due, in part, to a reduced risk of cardiovascular diseases. The protective effect has been attributable to polyphenols, which are potent vasodilators and have anti-thrombotic properties. Polyphenols have been shown to induce pronounced endothelium-dependent relaxations of arteries by causing the redox-sensitive PI3-kinase-dependent formation of nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF). The aim of the present study was to determine the role of the AMP-activated protein kinase (AMPK) in the red wine polyphenols (RWPs)-induced endothelial formation of NO and EDHF. METHODS AND RESULTS: Vascular reactivity was assessed in organ chambers. Cultured porcine coronary artery endothelial cells porcine coronary artery segements were used to study the phosphorylation level of endothelial NO synthase (eNOS) at serine 1177, and AMPK at the Threonine 172 by Western blot analysis and immunohistochemical staining. RWPs caused endothelium-dependent relaxations in rings from rat aorta and mesenteric artery, and in those from porcine coronary artery. NO-mediated relaxations to RWPs as assessed in the presence of indomethacin and charybdotoxin plus apamin, were inhibited by compound C (an inhibitor of AMPK). Compound C also reduced EDHF-mediated relaxations as assessed in the presence of indomethacin and N(G)-nitro L-arginine. In contrast, compound C did not affect endothelium-dependent relaxations to acetylcholine and those to sodium nitroprusside. Moreover, RWPs induced the phosphorylation of AMPK at threonine 172 and eNOS at serine 1177 in endothelial cells; these responses were inhibited by compound C. CONCLUSION: The present findings indicate that RWPs cause both NO and EDHF-mediated relaxations in several types of isolated arteries and that these effects are dependent on the activation of the AMP-activated protein kinase pathway.

[Development of Ethylcellulose/Eudragit matrix for controlled and continuous release of insulin]. / Developpement d'une matrice ethylcellulose/eudragit pour la liberation controlee et continue de l'insuline.

PURPOSE: Diabetes Type I is a chronic disease requiring insulin repeated injections by parenteral during a lifetime. This method of administration as well as traumatic can be a problem for adherence of patients to treatment. In order to overcome these difficulties, we considered the development of therapeutic transdermal drug delivery (TTDD) of insulin. MATERIAL AND METHOD: As active ingredient we used anhydrous human insulin Actarapid HM from Novo Nordisk laboratory, the excipients are ethyl cellulose, Eudragit RS 100 and butylphtalate. We developed two matrix Ethylcellulose/Eudragit in reports 1 and 2, in which are incorporated different proportions of insulin. RESULTS: The study of the release of insulin in phosphate buffer at pH 7.4, showed a continuous release profiles strongly depending on Ethylcellulose/Eudragit report and the initial charge of insulin. CONCLUSION: This study shows that the matrix Ethylcellulose/Eudragit lends itself to the development of a controlled release of insulin. This allows us to continue this work by combining this matrix with other elements for achieving an insulin TTDD.