Stemness of Human Pluripotent Cells: Hypoxia-Like Response Induced by Low Nitric Oxide

The optimization of conditions to promote the stemness of pluripotent cells in vitro is instrumental for their use in advanced therapies. We show here that exposure of human iPSCs and human ESCs to low concentrations of the chemical NO donor DETA/NO leads to stabilization of hypoxia-inducible factors (HIF-1α and HIF-2α) under normoxia, with this effect being dependent on diminished Pro 402 hydroxylation and decreased degradation by the proteasome. Moreover, the master genes of pluripotency, NANOG and OCT-4, were upregulated. NO also induces a shift in the metabolic profile of PSCs, with an increased expression of hypoxia response genes in glycolysis. Furthermore, a reduction in the mitochondrial membrane potential with lower oxygen consumption and increased expression of mitochondrial fusion regulators, such as DRP1, was observed. The results reported here indicate that NO mimics hypoxia response in human PSCs and enhances their stemness properties when cultured under normoxic conditions.E Caballano-Infantes was a doctoral FPU fellow from the Spanish government (FPU12/00184). This study was supported by grants from Consejería de Igualdad, Salud y Políticas Sociales, Junta de Andalucía (PI105/2010, TCMR06/009 and PI-0022) to FJ Bedoya and F Martin; from Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía (CTS-7127/2011) to FJ. Bedoya; from ISCIII cofunded by Fondos FEDER (RED-TERCEL RD 16-011-0034) and from Fundación Andaluza de I + D (Grant Al-Andalus Biopharma 2019-2) to B. Soria and from Servicio Andaluz de Salud (SAS 11245) and Ministerio de Economía y Competitividad- Secretaría de Estado de Investigación Desarrollo e Innovación (IPT-2011-1615-900000) to JR Tejedo.Ye