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
Tumor-associated macrophages (TAMs) display heterogeneous phenotypes. Yet the exact tissue cues that shape macrophage functional diversity are incompletely understood. Here we discriminate, spatially resolve and reveal the function of five distinct macrophage niches within malignant and benign breast and colon tissue. We found that SPP1 TAMs reside in hypoxic and necrotic tumor regions, and a novel subset of FOLR2 tissue resident macrophages (TRMs) supports the plasma cell tissue niche. We discover that IL4I1 macrophages populate niches with high cell turnover where they phagocytose dying cells. Significantly, IL4I1 TAMs abundance correlates with anti-PD1 treatment response in breast cancer. Furthermore, NLRP3 inflammasome activation in NLRP3 TAMs correlates with neutrophil infiltration in the tumors and is associated with poor outcome in breast cancer patients. This suggests the NLRP3 inflammasome as a novel cancer immunetherapy target. Our work uncovers context-dependent roles of macrophage subsets, and suggests novel predictive markers and macrophage subset-specific therapy targets.