Negative feedback regulation of growth factor signaling in adult spermatogonial stem cells

成体精原干细胞生长因子信号传导的负反馈调节

• 批准号: 10570919
• 负责人: Todd R Evans
• 金额: $ 36.44万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-01 至 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10570919
• 关键词: Ablation; Address; Adult; Biochemical; Biosensor; Cell Culture System; Cells; Clone Cells; DUSP6 protein; Data; Equilibrium; FGF2 gene; Feedback; Fibroblast Growth Factor; Future; Gene Family; Genes; Genetic; Genetic Diseases; Genetic Transcription; Genetically Engineered Mouse; Germ Cells; Goals; Growth; Growth Factor; Growth Factor Receptors; Hyperactivity; Image; Impairment; In Vitro; Infertility; Kinetics; Laboratories; MAP Kinase Gene; Mammals; Measurement; Methodology; Molecular; Mus; Outcome; Pathway interactions; Phenotype; Physiological; Population; Process; Production; Recovery; Regulation; Reporter; Role; Series; Signal Induction; Signal Transduction; Specificity; Spermatogonia; Stem cell transplant; Structure; System; Testing; Testis; Time; Translating; Transplantation; Up-Regulation; Work; experimental study; glial cell-line derived neurotrophic factor; improved; in vivo; member; mouse model; novel; preservation; prevent; real time monitoring; response; self-renewal; single-cell RNA sequencing; sperm cell; stem cell biomarkers; stem cell differentiation; stem cell function; stem cell niche; stem cell self renewal; stem cells; therapeutic target

Abstract Niche-derived growth factors (GFs) are essential for establishing and maintaining mammalian spermatogonial stem cells (SSCs) in the adult testis. In culture, however, optimal conditions for expansion of pure populations of self-renewing SSCs remain elusive. We recently found that mouse SSCs possess unexpectedly robust mechanisms to counter-regulate GF signaling by inducing expression of negative feedback regulators (NFRs), including members of the Spry and Dusp gene families. Abrogation of specific NFRs in SSCs led to increase ERK signaling, decreased expression of stem cell-associated genes in vitro and loss of stem cell activity upon transplantation, suggesting that excessive GF-dependent signaling is detrimental to SSC function and may favor differentiation. The cellular alterations that occur following perturbation of NFRs are unknown. However, our data imply that SSCs are programmed to limit ERK signaling within a narrow physiological range. This proposal addresses the mechanisms by which NFRs restrict GF signaling in SSCs, prevent unscheduled differentiation, and enable long-term propagation of SSC clones. Using genetic mouse models, SSC culture, transplantation analysis, and a newly-developed real-time biosensor for ERK activity, we address the following questions: (1) Which NFRs are required for SSC self-renewal? (2) How does ablation of NFRs result in loss of stem cell activity? (3) How do NFRs control the dynamic intracellular signaling cascades downstream of GF receptors? And (4) At which nodes in the ERK pathway do NFRs exert their actions? In addition to providing a rational basis to improve SSC culture systems, these studies will also identify novel adult SSC markers and shed light on mechanisms by which cross-talk between the niche and SSCs balances self-renewal and differentiation in vivo.

抽象的 利基衍生的增长因子（GFS）对于建立和维持哺乳动物至关重要 成人睾丸中的精子干细胞（SSC）。然而，在文化中， 自我更新SSC的纯种群的扩展仍然难以捉摸。我们最近发现 鼠标SSC具有出乎意料的鲁棒机制，可以通过 诱导负反馈调节器（NFR）的表达，包括SPRY的成员 和DUSP基因家族。 SSC中特定NFR的废除导致ERK信号的增加， 在体外与干细胞相关基因的表达降低和干细胞活性降低 移植，表明过度依赖GF的信号传导对SSC有害 功能，可能有利于差异化。扰动后发生的细胞改变 NFR是未知的。但是，我们的数据暗示SSC已编程以限制ERK 信号在狭窄的生理范围内。该提案通过 哪个NFR限制了SSC中的GF信号，防止分化的分化，并启用 SSC克隆的长期传播。使用遗传小鼠模型，SSC培养， 移植分析和新开发的ERK活动的实时生物传感器，我们 解决以下问题：（1）SSC自我更新需要哪些NFR？ （2）如何 NFR的消融是否会导致干细胞活性丧失？ （3）NFR如何控制动态 GF受体下游的细胞内信号传导？ （4）在哪个节点 ERK途径NFR会采取行动吗？除了提供合理的依据以改进 SSC培养系统，这些研究还将确定新颖的成人SSC标记并阐明 利基市场和SSC之间的交叉言语平衡的机制平衡了自我更新和 体内分化。