SUN-118 Interleukin-6 (IL-6) Decreases Mitochondrial Biogenesis In 3T3-L1 Pre-adipocytes And Adipocytes

The mitochondria are highly dynamic organelles specialized in metabolizing energy for the proper functioning of all cells. These organelles go through biogenesis cycles alternating between the fusion and fission of mitochondrial compartments, and adapt their morphology to the metabolic status of the cell, optimizing its function. During fusion, the mitochondria create networks that are essential during high mitochondrial function and energy usage. Conversely, fission is predominant in resting cells, during low energy demand and accountable for the removal of damaged mitochondria. Interleukin-6 (IL-6), a widely known inflammatory cytokine, has begun to be recognized for its role in the regulation of metabolism and mitochondrial function. Since normally functioning adipocytes are crucial in promoting metabolic health, in this study, we investigated the direct effect of IL-6 on mitochondrial morphology in adipocytes. To study the effect of IL-6 on mitochondria, we used 3T3-L1 pre-adipocytes and adipocytes as our cell culture model. On the 10(th) day after inducing differentiation, when majority of the cells showed the rounded, lipid droplet laden characteristics of adipocytes, the cells were treated with 200 mg/mL of IL-6 for 48 and 96 hours. The fluorescent dye, MitoTracker, was used to stain the mitochondria for imaging using confocal laser microscopy. Pre-adipocytes and adipocytes treated with IL-6 presented a more fragmented and punctate mitochondrial morphology compared to the control, suggesting that IL-6 promotes the fission rather than the fusion state of mitochondrial dynamics. A decrease in florescence intensity, which indicates decreased mitochondrial membrane potential, was observed preliminarily in some of the treatments. Overall, our results demonstrate that IL-6 may affect mitochondrial biogenesis, mitochondrial function and thus metabolic function in pre-adipocytes and adipocytes. In future, we will investigate IL-6 effects on mitochondrial function and gene expression.