Cellular effect of insulin on proliferation of monocytes (1011.4)

Abstract

Diet macronutrient composition affects insulin action(1). Insulin is essential for metabolic homeostasis in mammals(2). THP‐1 is a human myeloid leukemia cell line(3) which is a suitable model‐system for mimicking human monocytes and macrophages in metabolic inflammation, diabetes and vasculature‐related research(4‐6) . In this study, we used THP‐1 cells to investigate if insulin affect proliferation. Actively proliferating THP‐1 cells were serum starved prior to treatment with varying doses of insulin (20nM, 100nM and 1 µM) with a D‐glucose content of 11 mM or 22 mM for 24 hours (hrs) to 144 hrs. We found that the response was most evident at 24 hrs at 100 nM insulin (p<0.05). There was no stimulating effect of adding D‐glucose on proliferation. Based on the different insulin stimulation times (24, 48, 72, 96, 120 and 144 hrs), we found that insulin‐stimulated proliferation was most prominent following 24 hrs of exposure. This stimulatory effect on proliferation was reduced following longer exposure periods. Interestingly, we also observed that insulin affected morphology of monocytes and adherence. In conclusion, insulin may have proinflammatory effects by affecting several aspects of monocyte function, including proliferation and adherence; important factors for immune and vascular function.