Inhibition of Syk promotes chemical reprogramming of fibroblasts via metabolic rewiring and H2S production

Chemical compounds have recently been introduced as alternative and non-integrating inducers of pluripotent stem cell fate. However, chemical reprogramming is hampered by low efficiency and the molecular mechanisms remain poorly characterized. Here, we show that inhibition of spleen tyrosine kinase (Syk) by R406 significantly promotes mouse chemical reprogramming. Mechanistically, R406 alleviates Syk / calcineurin (Cn) / nuclear factor of activated T cells (NFAT) signaling-mediated suppression of glycine, serine, and threonine metabolic genes and dependent metabolites. Syk inhibition upregulates glycine level and downstream transsulfuration cysteine biosynthesis, promoting cysteine metabolism and cellular hydrogen sulfide (H2S) production. This metabolic rewiring decreased oxidative phosphorylation and ROS levels, enhancing chemical reprogramming. In sum, our study identifies Syk-Cn-NFAT signaling axis as a new barrier of chemical reprogramming and suggests metabolic rewiring and redox homeostasis as important opportunities for controlling cell fates.

Automated summary

Inhibition of spleen tyrosine kinase (Syk) by R406 enhances mouse chemical reprogramming by upregulating glycine level and transsulfuration cysteine biosynthesis, promoting cysteine metabolism and cellular hydrogen sulfide (H2S) production, which leads to decreased oxidative phosphorylation and ROS levels, ultimately enhancing the efficiency of chemical reprogramming.