MYCT1 as a moderator for signaling between human HSC and their niche

MYCT1 作为人类 HSC 与其生态位之间信号传导的调节剂

• 批准号: 10593103
• 负责人: Hanna Katri Annikki Mikkola
• 金额: $ 31.2万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10593103
• 关键词: Address; Affect; Biological Assay; Blood; Blood Cells; Cell Cycle Progression; Cell Line; Cell division; Cell physiology; Cells; Clinical; Cues; Data; Endocytosis; Endosomes; Endothelial Cells; Engraftment; Environment; Equilibrium; Functional disorder; Gene Expression; Genes; Hematologic Neoplasms; Hematological Disease; Hematopoiesis; Hematopoietic Cell Production; Hematopoietic Stem Cell Transplantation; Hematopoietic stem cells; Human; Inherited; Kinetics; Life; Link; MLLT3 gene; Mediating; Modeling; Molecular; Mus; Natural regeneration; Patients; Proteins; Receptor Signaling; Regulation; Signal Pathway; Signal Transduction; TGFBR1 gene; TGFBR2 gene; Therapeutic; Transforming Growth Factor beta; Transplantation; Vesicle; Work; clinical application; ethnic bias; ethnic minority; expression vector; extracellular; functional improvement; gain of function; hematopoietic stem cell expansion; hematopoietic stem cell niche; improved; insight; knock-down; loss of function; mutant; novel; novel strategies; overexpression; prevent; process improvement; programs; response; self-renewal; stem cell division; stem cell function; stem-like cell; stemness; transplantation therapy

SUMMARY Hematopoietic stem cells (HSC) need to integrate microenvironmental cues to switch their fate between quiescence, self-renewal, and differentiation, thereby sustaining hematopoiesis through life. However, the molecular programs governing HSC stemness become grossly dysregulated during culture, hindering our ability to expand functional HSCs for treating hematological diseases. Our data uncovered MYCT1 (Myc target 1) as human HSC regulatory factor that is critical for their expansion and engraftment, but becomes suppressed during differentiation and culture. We found that MYCT1 localizes in endosomes, interacts with vesicle components and signaling receptors with critical functions in HSCs (e.g. TGFBR1 and 2), and controls the rate of endocytosis, which modulates cell signaling and must be tightly regulated to maintain HSC stemness. Many genes dysregulated upon MYCT1 knockdown (KD) are linked to HSC division and self-renewal. We hypothesize that MYCT1 governs HSC stemness and their ability to balance between fate options by fine-tuning multiple signaling cues through the control of endocytosis. We have created a toolbox of MYCT1 knockdown and overexpression vectors, including various MYCT1 deletion mutants, that can be used in primary human HSPCs as well as HSC- like and endothelial cell line models to investigate MYCT1 mechanism of action. We will investigate how MYCT1- mediated control of endocytosis affects signaling in HSCs, and how this influences HSC cell-fate decisions including quiescence and asymmetric vs symmetric division. We will then assess if rescuing MYCT1 regulated processes improves the function of cultured human HSC, including those expanded using MLLT3 overexpression. Our work may open up new strategies to maintain HSC transplantability during ex vivo expansion and ultimately help broaden HSC clinical applications.

总结 造血干细胞（HSC）需要整合微环境线索，以在 静止，自我更新和分化，从而维持生命的造血。但 控制HSC干性的分子程序在培养过程中严重失调，阻碍了我们的能力， 以扩增用于治疗血液病的功能性HSC。我们的数据揭示了MYCT 1（Myc target 1）， 人HSC调节因子，对HSC的扩增和植入至关重要，但在移植过程中被抑制 分化与文化。我们发现MYCT 1定位于内体，与囊泡组分相互作用， 在HSC中具有关键功能的信号传导受体（例如TGFBR 1和2），并控制胞吞作用的速率， 其调节细胞信号传导并且必须被严格调节以维持HSC的干性。许多基因 MYCT 1敲低（KD）后失调的HSC与HSC分裂和自我更新有关。我们假设 MYCT 1通过微调多种信号调节HSC的干性及其在命运选择之间平衡的能力 通过控制内吞作用来提供线索。我们已经创建了一个MYCT 1敲低和过表达的工具箱， 载体，包括各种MYCT 1缺失突变体，其可用于原代人HSPC以及HSC-1。 和内皮细胞系模型，以研究MYCT 1的作用机制。我们将研究MYCT 1- 内吞作用的介导控制影响HSC中的信号传导，以及这如何影响HSC细胞命运决定 包括静止和不对称分裂与对称分裂。然后，我们将评估是否拯救MYCT 1调节 方法改善了培养的人HSC的功能，包括使用MLLT 3扩增的那些 过度表达我们的工作可能会开辟新的策略，以保持HSC的可移植性，在体外 扩大，并最终有助于扩大HSC的临床应用。