Impact of Calorie Restriction on Expression of Apoptotic and Inflammatory Genes in Diabetic Rat Model

Calorie restriction, the nutritional intervention which reduces calorie intake without incurring malnutrition has been reported to reduce inflammation and the expression of inflammatory genes. Diabetes is associated with low grade inflammation state. The effect of calorie restriction on the expression of apoptosis and inflammatory genes in male Wistar rats induced with diabetes was investigated and compared with the control group. The lung cells were harvested, isolated, incubated and observed for the formation of epithelial and/or fibroblast monolayer. The extracted total RNA was reverse transcribed into cDNA, and real-time PCR was carried out. The alveolar cells were cultured in growth media simulating calorie restriction and hyperglycemia and were observed for phenotypic changes and gene expression. Changes in morphology were observed in cells cultured in high glucose, resembling fibroblast phenotype, 10 days post culture. The expression levels of apoptotic genes such as bax, TNF-α, caspase 3 and caspase 8 and pro-inflammatory genes such as Rantes, iNOS, MCP-1, MIP-2 and IL-1 were substantially up regulated in the diabetes induced alveolar epithelial cells compared to that of non-diabetes induced alveolar epithelial cells suggesting that diabetes induced pathological changes in the lung were associated with the induction of apoptosis and inflammation. Overall, this study provides evidence that a planned calorie restriction in diabetes significantly down-regulates the expression levels of inflammatory and apoptotic genes, which is likely to improving metabolic outcomes in type 2 diabetes.