Chemical Screening Identifies Danofloxacin as a Self-Renewal Agonist of Embryonic Stem Cells through Alleviation of HDAC1-Mediated Deacetylation of Tert and Prdm10.

While significant advances have been made in maintaining stem cell pluripotency, the successful establishment of embryonic stem cells (ESCs) from various animal species in vitro remains challenging. This highlights the need for further optimization of culture conditions. Through compound library screening, we identified Danofloxacin, a small molecule, as a promoter of mouse ESC stemness. Danofloxacin enhances the formation of undifferentiated colonies and the generation of chimeric mice. Mechanistically, it suppresses HDAC1 expression and activity, resulting in increased acetylation of histone H3 at lysines 9 (H3K9ac) and 27 (H3K27ac), which in turn upregulates the expression of Tert and Prdm10. Functional assays revealed that overexpressing Tert or Prdm10 mimics Danofloxacin's effect on ESC self-renewal, whereas knockdown of either gene disrupts this process. Moreover, the elevated levels of H3K9ac and H3K27ac activate the PI3K/AKT and HIF-1α signaling pathways, both of which contribute to the transcriptional upregulation of Tert and Prdm10. These findings offer new insights into the pluripotency regulatory network and propose potential strategies for isolating ESCs from other species in vitro.