Effect of growth factors present in serum on insulin resistance and endothelial dysfunction in EA.hy926 cells

Insulin resistance is a pathophysiological function of Type II diabetes mellitus which can be comprehended by quantifying the parameters critical to the insulin signaling pathway. Serum has a profound role in evaluating cellular growth and metabolism in vitro. We hypothesize that the growth factors present in serum such as IGF, EGF, and FGF have an effect on the regulatory components of the insulin signaling pathway leading to insulin resistance. This study focuses on the metabolic effect of Fetal Bovine Serum (FBS) in endothelial (EA.hy926) cells. A dose and time-dependent treatment of FBS on the chosen cells was followed by assessing cell viability and glucose uptake capacity using MTT and 2-NBDG assays respectively. Spectrophotometric analysis of nitric oxide (NO) and lactate dehydrogenase (LDH) determined vascular homeostasis and no cytotoxic effects of the serum, respectively, in endothelial cells. These findings indicate that FBS at higher levels could possibly lead to loss of NO activity which in turn could impair endothelium-mediated dilation. The inhibition of the enzymatic activity of eNOS, which in response to the stress may activate the release of LDH in endothelial cells displaying cytotoxicity. In conclusion, our findings indicate that a specific concentration of serum exposure enhances insulin signaling and endothelium cell regulation by modulating glucose uptake and NO production.