Perturbation of single hematopoietic stem cell fates in artificial niches

Department of Microbiology and Immunology, BioX and Stem Cell Institute, Stanford University School of Medicine, CA 94305, USA.
Integrative Biology (Impact Factor: 3.76). 01/2009; 1(1):59-69. DOI: 10.1039/b815718a
Source: PubMed


Hematopoietic stem cells (HSCs) are capable of extensive self-renewal in vivo and are successfully employed clinically to treat hematopoietic malignancies, yet are in limited supply as in culture this self-renewal capacity is lost. Using an approach at the interface of stem cell biology and bioengineering, here we describe a novel platform of hydrogel microwell arrays for assessing the effects of either secreted or tethered proteins characteristic of the in vivo microenvironment, or niche, on HSC fate in vitro. Time-lapse microscopic analyses of single cells were crucial to overcoming inevitable heterogeneity of FACS-enriched HSCs. A reduction in proliferation kinetics or an increase in asynchronous division of single HSCs in microwells in response to specific proteins (Wnt3a and N-Cadherin) correlated well with subsequent serial long-term blood reconstitution in mice in vivo. Single cells that divided once in the presence of a given protein were capable of in vivo reconstitution, providing evidence of self-renewal divisions of HSCs in vitro. These results validate the hydrogel microwell platform as a broadly applicable paradigm for dissecting the regulatory role of specific signals within a complex stem cell niche.

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Available from: Helen M Blau, Aug 19, 2015
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