Effect of Silent Information Regulator on the Survival and Osteogenic Differentiation of Inflammatory Bone Marrow Mesenchymal Stem Cells by Regulating NF-κB Signaling Pathway

Abstract

Osteogenic differentiation of BMSCs is beneficial for osteoarthritis (OA) treatment. Silent information regulator (SIRT1) plays a role in endocrine diseases and aging-related diseases. However, the role of SIRT1 in OA has not yet been elucidated. Rat BMSCs were isolated and divided into control group, inflammation group (BMSCs were cultured with IL-6), SIRT1 group (SIRT1 agonist Resveratrol was added under the action of IL-6) followed by analysis of cell proliferation by MTT assay, Caspase 3 activity, ALP activity, expression of osteogenic genes Runx2 and OC and adipogenic differentiation gene PPARγ2 by Real time PCR, NF-κB expression by western blot and secretion of TNF-α and IL-6 by ELISA. In inflammation group, SIRT1 expression was significantly decreased, cell proliferation was significantly inhibited, and Caspase 3 activity was increased. Meanwhile, ALP activity, Runx2 and OC expression was decreased, PPARγ2 and NF-κB expression was increased, along with elevated TNF-α and IL-6 secretion compared to control (P < 0.05). Resveratrol can significantly promote the expression of SIRT1 in BMSCs of inflammation group, promote cell proliferation, decrease Caspase 3 activity, and increase Runx2 and OC expression. In addition, it decreased PPARγ2 and NF-κB expression and reduced the secretion of TNF-α and IL-6 (P < 0.05). The expression of SIRT1 was decreased in BMSCs under inflammation. SIRT1 overexpression in BMSCs under inflammation inhibits inflammation, promotes proliferation and osteogenic differentiation of BMSCs through regulating NF-κB signaling pathway.