- Yang, Zijiang;
- Concannon, John;
- Ng, Kelvin S;
- Seyb, Kathleen;
- Mortensen, Luke J;
- Ranganath, Sudhir;
- Gu, Fangqi;
- Levy, Oren;
- Tong, Zhixiang;
- Martyn, Keir;
- Zhao, Weian;
- Lin, Charles P;
- Glicksman, Marcie A;
- Karp, Jeffrey M
Pre-treatment or priming of mesenchymal stem cells (MSC) prior to transplantation can significantly augment the immunosuppressive effect of MSC-based therapies. In this study, we screened a library of 1402 FDA-approved bioactive compounds to prime MSC. We identified tetrandrine as a potential hit that activates the secretion of prostaglandin E2 (PGE2), a potent immunosuppressive agent, by MSC. Tetrandrine increased MSC PGE2 secretion through the NF-κB/COX-2 signaling pathway. When co-cultured with mouse macrophages (RAW264.7), tetrandrine-primed MSC attenuated the level of TNF-α secreted by RAW264.7. Furthermore, systemic transplantation of primed MSC into a mouse ear skin inflammation model significantly reduced the level of TNF-α in the inflamed ear, compared to unprimed cells. Screening of small molecules to pre-condition cells prior to transplantation represents a promising strategy to boost the therapeutic potential of cell therapy.