Tumor necrosis factor-α inhibition restores matrix formation by human adipose-derived stem cells in the late stage of chondrogenic differentiation

ARTICLE HIGHLIGHTS

Research background

During the induced differentiation, the inability of adipose-derived mesenchymal stem cells (ADSCs) to secret cartilage matrix durably has been one of the difficulties in cartilage tissue engineering. Therefore, understanding the changes in the culture system before and after ADSCs differentiation and improving the induction program can help improve the chondrogenic differentiation efficiency of ADSCs.

Research motivation

In the previous study, we conducted single-cell sequencing of ADSCs before and after chondrogenic differentiation and found that the expression levels of Matrix metalloproteinase 3 (MMP-3) and Tumor necrosis factor receptor superfamily member 12A (TNFRSF12A) were significantly increased. Therefore, we hypothesized that the accumulation of inflammatory levels in THE culture system resulted in decreased cartilage matrix secretion at the late stage of differentiation and designed this study for this reason.

Research objectives

To investigate the changes of tumor necrosis factor-α (TNF-α) and MMP-3 Levels in the culture system of ADSCs before and after chondrogenic differentiation. To confirm that TNF-α increased and decreased cartilage matrix secretion of ADSCs by activating the NF-KB pathway. To confirm that adding TNF-α inhibitor to chondrogenic medium could improve the chondrogenic differentiation efficiency of ADSCs.

Research methods

Treat ADSCs with chondrogenic medium containing TNF- α inhibitors, such as etanercept and infliximab. Then observe the changes of cartilage matrix secretion and the level of inflammation in the culture system through western blot, Elisa, immunofluorescence and toluidine blue staining.

Research results

During the differentiation of ADSCs, the expression levels of TNF-α and MMP-3 increased gradually, and the activation of NF-κB signaling pathway increased. Adding TNF-α inhibitors, etanercept (1 μg/mL) or inflixib (10 μg/mL), to the chondrogenic medium can reduce the activation of NF-κB pathway, alleviate the inflammation and preserve the secretion of cartilage matrix of ADSCs.

Research conclusions

When TNF-α increases and binds to its receptor, activates NF-κB pathway and reduces cartilage matrix secretion of ADSCs. TNF-α inhibitors can block the above process and improve the chondrogenic differentiation efficiency of ADSCs in vitro.

Research perspectives

In future studies, the TNF-α inhibitor etanercept or infliximab used in this study could be combined with the scaffold material to optimize the growth environment of ADSCs and make the drug release more durable and gentle, so as to achieve higher chondrogenic differentiation efficiency of ADSCs. And obtain a transplantable cartilage engineering material with similar properties to the natural cartilage tissue for the repair and treatment of cartilage defects, eventually.