Seminar: Metabolic regulation of the male germline stem cell niche
| Date/Time: | Tuesday, 10 Dec 2024 from 1:00 pm to 1:50 pm |
|---|---|
| Location: | 1414 Molecular Biology |
| Cost: | Free |
| Contact: | Danise Jones |
| Phone: | 515-294-6821 |
| Channel: | Research |
| Categories: | Lectures |
| Actions: | Download iCal/vCal | Email Reminder |
Synopsis: The capacity of stem cells to self-renew or differentiate has been attributed to distinct metabolic states. In the Drosophila testis stem cell niche, we have shown that both germline stem cells (GSCs) and somatic cyst stem cells (CySCs) employ strategies to control lipid levels to promote stem cell maintenance. When lipid catabolism is impaired, neutral lipids accumulate in lipid droplets (LDs) and GSCs and CySCs exit the niche to differentiate, suggesting a role for lipid metabolism in the control of stem cell maintenance. However, the precise mechanisms involved in stem cell homeostasis triggered by lipid accumulation remains unknown. In the testis, both niche and stem cell number decreases with age. Interestingly, LDs accumulate with age in "hub" niche cells. Downregulation of the lipogenesis factor sterol regulatory element binding protein (SREBP) prevented LD accumulation in hub cells with age, while ectopic activation of SREBP caused hub cell loss through their conversion into CySCs. Furthermore, SREBP activation downregulated the levels of Escargot, a member of the Snail family of transcription factors involved in hub maintenance. While some mechanisms have been described to contribute to the conversion of hub cells into stem cells, this is the first time that a lipid metabolism gene has been implicated in such phenomenon. Our findings highlight a critical role for metabolic factors in stem cell maintenance, providing a framework for investigating the impact of aging and metabolic diseases on stem cell function and tissue homeostasis.