Curcumin Inhibits Lipopolysaccharide-Induced Inflammation Through the HMGB1/NF-κB Signaling Pathway to Promote the Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells.

Abstract

Curcumin has strong anti-inflammatory properties and promotes the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). The aim of this study was to explore the role and potential molecular mechanism of curcumin in ameliorating osteogenic differentiation disorders caused by inflammation. We used LPS to induce an inflammatory response in hBMSCs. The expression of related mRNAs and proteins was detected by RT‒qPCR, Western blotting, immunofluorescence, and ELISA. The osteogenic differentiation of hBMSCs was detected by alkaline phosphatase (ALP) staining and alizarin red S (ARS) staining. The results showed that after LPS treatment, the levels of the inflammatory cytokines TNF-α, IL-6 and IL-1β in hBMSCs increased, and the activity of ALP, the level of calcium salt deposition and the expression levels of the osteogenic proteins Runx2, COL1, OCN and OPN significantly decreased. The curcumin treatment alleviated this effect. These results indicated that curcumin improved the LPS-induced inflammation and osteogenic differentiation disorder in hBMSCs. Further studies revealed that the therapeutic effect of curcumin was caused by the inhibition of HMGB1 expression. From a mechanistic perspective, curcumin inhibits LPS-induced inflammation by inhibiting the expression of HMGB1, thereby inhibiting the NF-κB pathway and activating the NRF2 pathway, thereby improving the disordered osteogenic differentiation of hBMSCs. In conclusion, curcumin can reduce the LPS-induced inflammation of hBMSCs and ameliorate their osteogenic differentiation disorders.