A fundamental question in hematopoietic stem cell (HSC) biology is how self-renewal is controlled. Here we show that the molecular regulation of two critical elements of self-renewal, inhibition of differentiation and induction of proliferation, can be uncoupled, and we identify Notch signaling as a key factor in inhibiting differentiation. Using transgenic Notch reporter mice, we found that Notch signaling was active in HSCs in vivo and downregulated as HSCs differentiated. Inhibition of Notch signaling led to accelerated differentiation of HSCs in vitro and depletion of HSCs in vivo. Finally, intact Notch signaling was required for Wnt-mediated maintenance of undifferentiated HSCs but not for survival or entry into the cell cycle in vitro. These data suggest that Notch signaling has a dominant function in inhibiting differentiation and provide a model for how HSCs may integrate multiple signals to maintain the stem cell state.
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http://dx.doi.org/10.1038/ni1164 | DOI Listing |
Life Sci
January 2025
TaiKang Medical School (School of Basic Medical Sciences), Wuhan University, Wuhan, China; Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China. Electronic address:
Aims: Vertebrates vary greatly in their abilities to regenerate injured hearts. Zebrafish possess a remarkable capacity for cardiac regeneration, making them an excellent model for regeneration research. Recent studies have reported the activation and underlying regulatory mechanisms of leptin b (lepb) and the leptin b-linked enhancer (LEN) in injured hearts.
View Article and Find Full Text PDFJ Biol Chem
January 2025
The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada, M5G 1X8; Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, ON, Canada, M5G 2M9. Electronic address:
The NUMB gene encodes a conserved adaptor protein with roles in asymmetric cell division and cell fate determination. First described as an inhibitor of Notch signaling, multi-functional NUMB proteins regulate multiple cellular pathways through protein complexes with ubiquitin ligases, polarity proteins and the endocytic machinery. The vertebrate NUMB protein isoforms were identified over two decades ago, yet the majority of functional studies exploring NUMB function in endocytosis, cell migration and adhesion, development and disease have largely neglected the potential for distinct isoform activity in design and interpretation.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
State Key Laboratory of Fire Science, University of Science and Technology of China, 443 Huangshan Road, Hefei 230027, P. R.China.
The next generation of stretchable electronics seeks to integrate superior mechanical properties with sustainability and sensing stability. Ionically conductive and liquid-free elastomers have gained recognition as promising candidates, addressing the challenges of evaporation and leakage in gel-based conductors. In this study, a sustainable polymeric deep eutectic system is synergistically integrated with amino-terminated hyperbranched polyamide-modified fibers and aluminum ions, forming a conductive supramolecular network with significant improvements in mechanical performance.
View Article and Find Full Text PDFSensors (Basel)
January 2025
Laboratory of Vibration and Noise, Naval University of Engineering, Wuhan 430033, China.
Pulsation noise in the piping system generated by the excitation of the pump source seriously affects the reliability of the pipeline system and mechanical equipment. The active noise control can effectively suppress the low-frequency noise in the liquid-filled pipeline. Active control methods with intrusive secondary sources generally use dynamic pressure sensors or hydrophones to collect signals, which destroy the structure of the pipe.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Laboratory for Testing and Materials, Department of Mechanics, School of Applied Mathematical and Physical Sciences, National Technical University of Athens, Zografou Campus, 157 73 Athens, Greece.
The fracture process of heterogeneous materials is studied here in the framework of the discipline of Non-Extensive Statistical Mechanics. Acoustic emission data provided by an experimental protocol with concrete specimens, plain or fiber-reinforced, under bending are taken advantage of. This innovation of the study lies in the fact that the analysis of the acoustic activity is implemented in terms of the energy content of the acoustic signals rather than of their interevent time or their interevent distance.
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