mTORC1-dependent and -independent regulation of stem cell renewal, differentiation, and mobilization
Autor: | Shan Jiang, Lynda Chin, Boyi Gan, David A. Williams, Abel Sanchez-Aguilera, Ergun Sahin, Kenneth L. Scott, David J. Kwiatkowski, Ronald A. DePinho |
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Rok vydání: | 2008 |
Předmět: |
congenital
hereditary and neonatal diseases and abnormalities Somatic cell Regulator mTORC1 Mechanistic Target of Rapamycin Complex 1 Biology Tuberous Sclerosis Complex 1 Protein Mice Bone Marrow Cell Movement Tuberous Sclerosis Complex 2 Protein medicine Animals Mice Knockout Multidisciplinary Cell growth TOR Serine-Threonine Kinases Tumor Suppressor Proteins Microfilament Proteins Proteins Hematopoietic stem cell Cell Differentiation Biological Sciences Hematopoietic Stem Cells Cell biology Mice Inbred C57BL Haematopoiesis Phenotype medicine.anatomical_structure Multiprotein Complexes biological phenomena cell phenomena and immunity TSC2 Stem cell Carrier Proteins Cell Division Signal Transduction Transcription Factors |
Zdroj: | Proceedings of the National Academy of Sciences. 105:19384-19389 |
ISSN: | 1091-6490 0027-8424 |
DOI: | 10.1073/pnas.0810584105 |
Popis: | The Tuberous Sclerosis Complex component, TSC1, functions as a tumor suppressor via its regulation of diverse cellular processes, particularly cell growth. TSC1 exists in a complex with TSC2 and functions primarily as a key negative regulator of mammalian target of rapamycin complex 1 (mTORC1) signaling and protein synthesis, although the TSC1/TSC2 complex also shows mTORC1-independent outputs to other pathways. Here, we explored the role of TSC1 in various aspects of stem cell biology and dissected the extent to which TSC1 functions are executed via mTORC1-dependent versus mTORC1-independent pathways. Using hematopoietic stem cells (HSCs) as a model system, we demonstrate that somatic deletion of TSC1 produces striking stem cell and derivative effector cell phenotypes characterized by increased HSC cell cycling, mobilization, marked progressive depletion, defective long-term repopulating potential, and hematopoietic lineage developmental aberrations. On the mechanistic level, we further establish that TSC1 regulation of HSC quiescence and long-term repopulating potential and hematopoietic lineage development is mediated through mTORC1 signaling. In contrast, TSC1 regulation of HSC mobilization is effected in an mTORC1-independent manner, and gene profiling and functional analyses reveals the actin-bundling protein FSCN1 as a key TSC1/TSC2 target in the regulation of HSC mobilization. Thus, TSC1 is a critical regulator of HSC self-renewal, mobilization, and multilineage development and executes these actions via both mTORC1-dependent and -independent pathways. |
Databáze: | OpenAIRE |
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