scholarly journals Hematopoietic Stem Cells: Nature and Niche Nurture

2021 ◽  
Vol 8 (5) ◽  
pp. 67
Author(s):  
Geoffrey Brown

Like all cells, hematopoietic stem cells (HSCs) and their offspring, the hematopoietic progenitor cells (HPCs), are highly sociable. Their capacity to interact with bone marrow niche cells and respond to environmental cytokines orchestrates the generation of the different types of blood and immune cells. The starting point for engineering hematopoiesis ex vivo is the nature of HSCs, and a longstanding premise is that they are a homogeneous population of cells. However, recent findings have shown that adult bone marrow HSCs are really a mixture of cells, with many having lineage affiliations. A second key consideration is: Do HSCs “choose” a lineage in a random and cell-intrinsic manner, or are they instructed by cytokines? Since their discovery, the hematopoietic cytokines have been viewed as survival and proliferation factors for lineage committed HPCs. Some are now known to also instruct cell lineage choice. These fundamental changes to our understanding of hematopoiesis are important for placing niche support in the right context and for fabricating an ex vivo environment to support HSC development.

Blood ◽  
2009 ◽  
Vol 113 (6) ◽  
pp. 1250-1256 ◽  
Author(s):  
Satoshi Yamazaki ◽  
Atsushi Iwama ◽  
Shin-ichiro Takayanagi ◽  
Koji Eto ◽  
Hideo Ema ◽  
...  

Abstract Hematopoietic stem cells (HSCs) reside in a bone marrow niche in a nondividing state from which they occasionally are aroused to undergo cell division. Yet, the mechanism underlying this unique feature remains largely unknown. We have recently shown that freshly isolated CD34−KSL hematopoietic stem cells (HSCs) in a hibernation state exhibit inhibited lipid raft clustering. Lipid raft clustering induced by cytokines is essential for HSCs to augment cytokine signals to the level enough to re-enter the cell cycle. Here we screened candidate niche signals that inhibit lipid raft clustering, and identified that transforming growth factor-β (TGF-β) efficiently inhibits cytokine-mediated lipid raft clustering and induces HSC hibernation ex vivo. Smad2 and Smad3, the signaling molecules directly downstream from and activated by TGF-β receptors were specifically activated in CD34−KSL HSCs in a hibernation state, but not in cycling CD34+KSL progenitors. These data uncover a critical role for TGF-β as a candidate niche signal in the control of HSC hibernation and provide TGF-β as a novel tool for ex vivo modeling of the HSC niche.


2015 ◽  
Vol 39 (10) ◽  
pp. 1099-1110 ◽  
Author(s):  
Iordanis Pelagiadis ◽  
Eftichia Stiakaki ◽  
Christianna Choulaki ◽  
Maria Kalmanti ◽  
Helen Dimitriou

2016 ◽  
Vol 364 (3) ◽  
pp. 573-584 ◽  
Author(s):  
Patrick Wuchter ◽  
Rainer Saffrich ◽  
Stefan Giselbrecht ◽  
Cordula Nies ◽  
Hanna Lorig ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Huihong Zeng ◽  
Jiaoqi Cheng ◽  
Ying Fan ◽  
Yingying Luan ◽  
Juan Yang ◽  
...  

Development of hematopoietic stem cells is a complex process, which has been extensively investigated. Hematopoietic stem cells (HSCs) in mouse fetal liver are highly expanded to prepare for mobilization of HSCs into the fetal bone marrow. It is not completely known how the fetal liver niche regulates HSC expansion without loss of self-renewal ability. We reviewed current progress about the effects of fetal liver niche, chemokine, cytokine, and signaling pathways on HSC self-renewal, proliferation, and expansion. We discussed the molecular regulations of fetal HSC expansion in mouse and zebrafish. It is also unknown how HSCs from the fetal liver mobilize, circulate, and reside into the fetal bone marrow niche. We reviewed how extrinsic and intrinsic factors regulate mobilization of fetal liver HSCs into the fetal bone marrow, which provides tools to improve HSC engraftment efficiency during HSC transplantation. Understanding the regulation of fetal liver HSC mobilization into the fetal bone marrow will help us to design proper clinical therapeutic protocol for disease treatment like leukemia during pregnancy. We prospect that fetal cells, including hepatocytes and endothelial and hematopoietic cells, might regulate fetal liver HSC expansion. Components from vascular endothelial cells and bones might also modulate the lodging of fetal liver HSCs into the bone marrow. The current review holds great potential to deeply understand the molecular regulations of HSCs in the fetal liver and bone marrow in mammals, which will be helpful to efficiently expand HSCs in vitro.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2358-2358
Author(s):  
Ali Nowrouzi ◽  
Africa Gonzales-Murillo ◽  
Anna Paruzynski ◽  
Ariana Jacome ◽  
Paula Rio ◽  
...  

Abstract Improved protocols using lentiviral vectors have been established with minimal cytokine exposure and short transduction times proving more suitable for overcoming the disease-specific challenge in correcting functionally defective hematopoietic stem cells (HSCs) of Fanconi Anemia (FA) patients. Bone marrow (BM) cells from FA patients were transduced ex vivo with lentiviral vectors (LVs) expressing FANCA and/or EGFP using optimized conditions to preserve the repopulating properties of the primitive hematopoietic stem cells (manuscript submitted). In a forward preclinical screening of possible LV-induced side effects we analyzed the insertional inventory in colonies generated by FA BM cells previously transduced with the LVs. We have established and optimized DNA and RNA isolation procedures for minimal cell numbers, suitable for large scale screening of colony forming cell (CFC) derived colonies by linear amplification-mediated PCR (LAM-PCR) and massive parallel pyrosequencing (454 GS Flx system; Roche). This approach is applicable for detecting early indicators of clonal selection, and is based on the analysis of common integration sites (CIS) and non-random distribution of vector insertions in particular genomic loci. From a total of 180 CFC-derived colonies expressing the EGFP LV marker gene, 298 vector insertions could be sequenced and mapped to the human genome. The analysis of vector targeted gene coding regions showed a non-random genomic distribution of LV insertions, with a significant overrepresentation of RefSeq genes that are part of distinct functional categories. Accordingly vector associated genes are predominantly involved in cellular signal cascades regulated by the MAP Kinase family known to be involved in a wide variety of cellular processes such as proliferation, differentiation, transcription regulation and development. Apart from the observed high integration frequency in genes (>80%), partial loss of vector LTR nucleotides was detected in >10% of the integrants (3–25bp). Notably, >20% of the lentiviral insertions were found to be located in CIS of predominantly 2nd order. Further screening assays of LV transduced CFC-derived colonies will allow a deeper investigation in the functional consequences of such CIS targeting in gene therapy protocols of FA. However our results suggest that the LV transduction of FA BM progenitors leads to a relatively high frequency of insertions in CIS which may be indicative of an insertion based (specific) selection mechanism. We herby show that the ex vivo large scale integration site analyses of CFC-derived colonies from patients considered to undergo gene therapeutic treatments constitutes a robust approach, which combined with mouse preclinical biosafety studies will help to improve the safety of clinical gene therapy protocols. The non-random distribution of LV integrations in CIS associated genes and in genes involved in particular cellular pathways may be indicative for the altered biochemical pathways characteristic of FA stem cells, with reported defects in DNA repair and self-renewal.


2013 ◽  
Vol 4 (3) ◽  
pp. 220-230 ◽  
Author(s):  
Shahina Akhter ◽  
Md. Mashiar Rahman ◽  
Hyun Seo Lee ◽  
Hyeon-Jin Kim ◽  
Seong-Tshool Hong

2012 ◽  
Vol 1266 (1) ◽  
pp. 72-77 ◽  
Author(s):  
Fumio Arai ◽  
Kentaro Hosokawa ◽  
Hirofumi Toyama ◽  
Yoshiko Matsumoto ◽  
Toshio Suda

2019 ◽  
Vol 47 (5) ◽  
pp. 656-660 ◽  
Author(s):  
Sundeep Chandra ◽  
Patrizia Cristofori ◽  
Carlos Fonck ◽  
Charles A. O’Neill

A therapeutic option for monogenic disorders is gene therapy with ex vivo-transduced autologous hematopoietic stem cells (HSCs). Safety or efficacy studies of ex vivo-modified HSCs are conducted in humanized mouse models after ablation of the murine bone marrow and transfer of human CD34+ HSCs. Engrafted human CD34+ cells migrate to bone marrow and differentiate into various human hematopoietic lineages. A 12-week study was conducted in NSG™ mice to evaluate engraftment, differentiation, and safety of human CD34+ cells that were transduced ( ex vivo) with a proprietary lentiviral vector encoding a human gene (BMRN-1) or a mock (green fluorescent protein) vector. Several mice intravenously injected with naive CD34+ cells or transduced CD34+ cells had variable lymphohistiocytic inflammatory cell infiltrates and microgranulomas in the liver and lungs consistent with graft-versus-host disease (GVHD). Spleen, bone marrow, stomach, reproductive tract, but not the skin had similar inflammatory changes. Ex vivo viral transduction of CD34+ cells did not impact engraftment or predispose to xenogeneic GVHD.


Sign in / Sign up

Export Citation Format

Share Document