The effect of a preparation of minerals, vitamins and trace elements on the cardiac gene expression pattern in male diabetic rats

BACKGROUND: Diabetic patients have an increased risk of developing cardiovascular diseases, which are the leading cause of death in developed countries. Although multivitamin products are widely used as dietary supplements, the effects of these products have not been investigated in the diabetic heart yet. Therefore, here we investigated if a preparation of different minerals, vitamins, and trace elements (MVT) affects the cardiac gene expression pattern in experimental diabetes. METHODS: Two-day old male Wistar rats were injected with streptozotocin (i.p. 100 mg/kg) or citrate buffer to induce diabetes. From weeks 4 to 12, rats were fed with a vehicle or a MVT preparation. Fasting blood glucose measurement and oral glucose tolerance test were performed at week 12, and then total RNA was isolated from the myocardium and assayed by rat oligonucleotide microarray for 41012 oligonucleotides. RESULTS: Significantly elevated fasting blood glucose concentration and impaired glucose tolerance were markedly improved by MVT-treatment in diabetic rats at week 12. Genes with significantly altered expression due to diabetes include functional clusters related to cardiac hypertrophy (e.g. caspase recruitment domain family, member 9; cytochrome P450, family 26, subfamily B, polypeptide; FXYD domain containing ion transport regulator 3), stress response (e.g. metallothionein 1a; metallothionein 2a; interleukin-6 receptor; heme oxygenase (decycling) 1; and glutathione S-transferase, theta 3), and hormones associated with insulin resistance (e.g. resistin; FK506 binding protein 5; galanin/GMAP prepropeptide). Moreover the expression of some other genes with no definite cardiac function was also changed such as e.g. similar to apolipoprotein L2; brain expressed X-linked 1; prostaglandin b2 synthase (brain). MVT-treatment in diabetic rats showed opposite gene expression changes in the cases of 19 genes associated with diabetic cardiomyopathy. In healthy hearts, MVT-treatment resulted in cardiac gene expression changes mostly related to immune response (e.g. complement factor B; complement component 4a; interferon regulatory factor 7; hepcidin). CONCLUSIONS: MVT-treatment improved diagnostic markers of diabetes. This is the first demonstration that MVT-treatment significantly alters cardiac gene expression profile in both control and diabetic rats. Our results and further studies exploring the mechanistic role of individual genes may contribute to the prevention or diagnosis of cardiac complications in diabetes

Selenium and copper in type 2 diabetes mellitus - more doubt than certainty

Type 2 diabetes mellitus (T2DM) is one of the most common chronic illnesses nearly all over the world and the prevalence of this disorder is still growing. Particularly in industrialized countries, it has become the most serious global medical and public problem, next to cancer and cardiovascular diseases. Despite intensive developments in the research on T2DM pathogenesis, the impact of nutritional factors, and particularly the effect of trace elements, on the development of this disease has not been identified completely, although relationships between some elements, e.g. Zn, Fe, Cr, and T2DM have been described in detail. Critical review of the literature indicates that the majority of inconsistencies appear in studies on Cu and Se: on the one hand, these minerals have strong antioxidant properties and even insulin-mimetic action; on the other hand, an increased risk of T2DM positively correlates with a high dietary intake of Se and Cu or supplementation with these elements. High content of these minerals in diets observed in selected countries and/or increasing popularity of dietary supplementation with Se or Cu, especially among chronically ill patients including ones with T2DM, can cause distortions in the molecular pathways of glucose metabolism. The influence of these minerals on inducing diabetic complications is even more vague and depends on several factors, e.g. the body status of these and other trace elements, the type of complications and the duration of T2DM. The relationship between T2DM and the status of Se and Cu is complex and bidirectional, thus a well-balanced diet providing these trace elements in proper amounts, according to the demand of an organism, may be one of the strategies in reducing the risk of T2DM and its complications