Role of Sirt3 in Lipid Generation

Abstract

Sirt3 is a major mitochondrial deacetylase which has important roles in regulation of metabolic homeostasis and metabolic diseases. ST2 cells are mesenchymal stem cells taken from bone marrow. The purpose of this research is to identify if Sirt3 plays a role in marrow adipogenesis to regulate insulin sensitivity through adipokines, especially adiponectin using ST2 cell models.Particularly, we used the gain‐function of Sirt3 in ST2 cells to assess the role of Sirt3 in adipogenesis. We were able to successfully overexpress Sirt3 and differentiate ST2 cells into adipocytes. We found that the induction of Sirt3 leads to increased adipogenesis compared to controls. The increase in adipogenesis was in line with elevated triglyceride levels in Sirt3 overexpression compared to controls (P < 0.01 in day 5 and P < 0.05 in day 7 after differentiation). This data is consistent with the increase in percentage area of adipocytes, which was highly significant in Sirt3 overexpression than that in the controls using Oil Red O staining (P< 0.01). The induction of adipogenesis by Sirt3 is associated with increased gene expression of adipocyte markers as well as adiponectin/adipokines.In addition, we inhibit Sirt3 function in ST2 cells using an inhibitor of Sirt3 called 3‐TYP. We treated cells with 50μM and 100M of 3‐TYP, versus control. Our results show that ST2 cells treated with Sirt3 inhibitor decreased adipogenesis by reduced area of adipocytes compared to controls especially at 100μM of 3‐TYP (P<0.05). Triglyceride measurements of 3‐TYP treated cells versus controls showed consistent results with reduced adipogenesis, especially at 100 μM on day 5 (p‐value <0.001). The expression levels of adipocyte markers and adiponectin/adipokines were statistically significantly reduced compared to the controls.These statistically significant consistent data suggest that Sirt3 gene plays an important role in modulating adipogenesis and adiponectin/adipokines expression. We hope our study contributes to the efforts of revealing Sirt3 functions in metabolic homeostasis and diseases. The ultimate goal is to use Sirt3 as a potential target in treating insulin resistance and other metabolic abnormalities.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.