Mesenchymal Stem Cell Conditioned Medium Induces Differentiation of Bone Mesenchymal Stem Cells and Affects the Secretion of IL-6 and IL-1β in Inflammatory Environment

Abstract

BMSCs can be an ideal tissue repair seed cell. Inflammation affects bone repair and bone damage. Our study evaluated the effects of mesenchymal stem cell conditioned medium on BMSCs differentiation and IL-6 and IL-1β secretion in inflammatory environment in vitro. Rat BMSCs were isolated and randomly divided into control group, inflammation group (treated with LPS) and induction group (mesenchymal stem cell conditioned medium in the presence of LPS) followed by analysis of BMSCs proliferation by MTT assay, Caspase 3 activity, expression of type II collagen, Runx2, OC and PPARγ 2 by real-time PCR, ALP activity, and secretion of IL-6 and IL-1β by ELISA. In inflammation group, BMSCs proliferation was significantly inhibited and Caspase 3 activity was significantly increased, along with decreased expression of type II collagen, Runx2 and OC, reduced ALP activity of ALP, increased PPARγ2 and the secretion of IL-6 and IL-1β (P < 0.05). Induction group showed significantly promoted BMSCs proliferation, decreased Caspase 3 activity, upregulated type II collagen, Runx2 and OC, elevated ALP activity, decreased PPARγ2 expression and IL-6 and IL-1β secretion compared to inflammation group (P < 0.05). Mesenchymal stem cell conditioned medium induces proliferation of BMSCs in an inflammatory environment, inhibits apoptosis and adipogenic differentiation, promotes osteogenic differentiation, and inhibits the secretion of inflammatory cytokines IL-6 and IL-1β.