RESUMEN
Salivary gland homeostasis and regeneration after radiotherapy depend significantly on progenitor cells. However, the lineage of submandibular gland (SMG) progenitor cells remains less defined compared with other normal organs. Here, using a mouse strain expressing regulated CreERT2 recombinase from the endogenous Tert locus, we identify a distinct telomerase-expressing (TertHigh) cell population located in the ductal region of the adult SMG. These TertHigh cells contribute to ductal cell generation during SMG homeostasis and to both ductal and acinar cell renewal 1 year after radiotherapy. TertHigh cells maintain self-renewal capacity during in vitro culture, exhibit resistance to radiation damage, and demonstrate enhanced proliferative activity after radiation exposure. Similarly, primary human SMG cells with high Tert expression display enhanced cell survival after radiotherapy, and CRISPR-activated Tert in human SMG spheres increases proliferation after radiation. RNA sequencing reveals upregulation of "cell cycling" and "oxidative stress response" pathways in TertHigh cells following radiation. Mechanistically, Tert appears to modulate cell survival through ROS levels in SMG spheres following radiation damage. Our findings highlight the significance of TertHigh cells in salivary gland biology, providing insights into their response to radiotherapy and into their use as a potential target for enhancing salivary gland regeneration after radiotherapy.
Asunto(s)
Homeostasis , Regeneración , Telomerasa , Telomerasa/metabolismo , Telomerasa/genética , Animales , Homeostasis/genética , Homeostasis/efectos de la radiación , Ratones , Regeneración/efectos de la radiación , Regeneración/genética , Humanos , Glándulas Salivales/efectos de la radiación , Glándulas Salivales/metabolismo , Glándulas Salivales/citología , Proliferación Celular/efectos de la radiación , Proliferación Celular/genética , Supervivencia Celular/efectos de la radiación , Supervivencia Celular/genética , Glándula Submandibular/efectos de la radiación , Glándula Submandibular/metabolismo , Células Madre/efectos de la radiación , Células Madre/metabolismo , Células Madre/citología , Radioterapia/efectos adversos , Especies Reactivas de Oxígeno/metabolismo , Células CultivadasRESUMEN
Generating primordial germ cell-like cells (PGCLCs) from human pluripotent stem cells (hPSCs) advances studies of human reproduction and development of infertility treatments, but often entails complex 3D aggregates. Here we develop a simplified, monolayer method to differentiate hPSCs into PGCs within 3.5 days. We use our simplified differentiation platform and single-cell RNA-sequencing to achieve further insights into PGCLC specification. Transient WNT activation for 12 h followed by WNT inhibition specified PGCLCs; by contrast, sustained WNT induced primitive streak. Thus, somatic cells (primitive streak) and PGCLCs are related-yet distinct-lineages segregated by temporally-dynamic signaling. Pluripotency factors including NANOG are continuously expressed during the transition from pluripotency to posterior epiblast to PGCs, thus bridging pluripotent and germline states. Finally, hPSC-derived PGCLCs can be easily purified by virtue of their CXCR4+PDGFRA-GARP- surface-marker profile and single-cell RNA-sequencing reveals that they harbor transcriptional similarities with fetal PGCs.