Reference - Detail
|Chang YC, Tu H, Huang TW, Xu BW, Pi H.
|Upregulated TNF/Eiger signaling mediates stem cell recovery and tissue homeostasis during nutrient resupply in Drosophila testis.
Stem cell activity and cell differentiation is robustly influenced by the nutrient availability in the gonads. The signal that connects nutrient availability to gonadal stem cell activity remains largely unknown. In this study, we show that tumor necrosis factor Eiger (Egr) is upregulated in testicular smooth muscles as a response to prolonged protein starvation in Drosophila testis. While Egr is not essential for starvation-induced changes in germline and somatic stem cell numbers, Egr and its receptor Grindelwald influence the recovery dynamics of somatic cyst stem cells (CySCs) upon protein refeeding. Moreover, Egr is also involved in the refeeding-induced, ectopic expression of the CySC self-renewal protein and the accumulation of early germ cells. Egr primarily acts through the Jun N-terminal kinase (JNK) signaling in Drosophila. We show that inhibition of JNK signaling in cyst cells suppresses the refeeding-induced abnormality in both somatic and germ cells. In conclusion, our study reveals both beneficial and detrimental effects of Egr upregulation in the recovery of stem cells and spermatogenesis from prolonged protein starvation.
|Animals Cell Differentiation Dietary Proteins / administration & dosage Dietary Proteins / metabolism* Drosophila Proteins / agonists Drosophila Proteins / genetics* Drosophila Proteins / metabolism Drosophila melanogaster / cytology Drosophila melanogaster / genetics* Drosophila melanogaster / growth & development Drosophila melanogaster / metabolism Eating / physiology Gene Expression Regulation, Developmental Homeostasis / genetics JNK Mitogen-Activated Protein Kinases / genetics* JNK Mitogen-Activated Protein Kinases / metabolism MAP Kinase Signaling System Male Membrane Proteins / agonists Membrane Proteins / genetics* Membrane Proteins / metabolism Spermatogenesis / drug effects Spermatogenesis / genetics Spermatozoa / cytology Spermatozoa / drug effects Spermatozoa / metabolism* Starvation / genetics Starvation / metabolism Stem Cell Niche / genetics Stem Cells / cytology Stem Cells / drug effects Stem Cells / metabolism* Testis / cytology Testis / drug effects Testis / growth & development Testis / metabolism