Adaptive response of hMSC-derived osteoprogenitors to LPS enriched environment

Objective: To investigate the cellular responsiveness of hMSCs osteoprogenitors to both the gram-positive and gram-negative endotoxins: lipoteichoic acid (LTA, Streptococcus pyogenes) and lipopolysaccharides (LPS, Escherichia coli).

Methods: The cellular responsiveness of hMSC-derived osteoprogenitors to LTA and LPS was evaluated by the expression of Toll-Like Receptors (TLRs), specifically TLR2 and TLR4, using quantitative PCR.

Results: Prolonged LPS challenge upregulated the osteogenic differentiation of hMSCs. TLR2 and TLR4 gene expressed in hMSCs or its derived osteoprogenitors.

Conclusions: Under the influence of LPS, the hMSC-derived osteoprogenitors showed a paradoxically reduced TLR2 and TLR4 gene expression pattern. This adaptive response of hMSC-derived osteoprogenitors in a bacterial endotoxin enriched (LPS) environment suggests a possibly regulatory mechanism in maintaining homeostasis.

Significance: Our novel findings support the potential of using hMSCs as a biological graft.