scholarly journals A chromatin modulator sustains self-renewal and enables differentiation of postnatal neural stem and progenitor cells

2019 ◽  
Vol 12 (1) ◽  
pp. 4-16 ◽  
Author(s):  
Kushani Shah ◽  
Gwendalyn D King ◽  
Hao Jiang

Abstract It remains unknown whether H3K4 methylation, an epigenetic modification associated with gene activation, regulates fate determination of the postnatal neural stem and progenitor cells (NSPCs). By inactivating the Dpy30 subunit of the major H3K4 methyltransferase complexes in specific regions of mouse brain, we demonstrate a crucial role of efficient H3K4 methylation in maintaining both the self-renewal and differentiation capacity of postnatal NSPCs. Dpy30 deficiency disrupts development of hippocampus and especially the dentate gyrus and subventricular zone, the major regions for postnatal NSC activities. Dpy30 is indispensable for sustaining the self-renewal and proliferation of NSPCs in a cell-intrinsic manner and also enables the differentiation of mouse and human neural progenitor cells to neuronal and glial lineages. Dpy30 directly regulates H3K4 methylation and the induction of several genes critical in neurogenesis. These findings link a prominent epigenetic mechanism of gene expression to the fundamental properties of NSPCs and may have implications in neurodevelopmental disorders.

2019 ◽  
Author(s):  
Kushani Shah ◽  
Gwendalyn D. King ◽  
Hao Jiang

ABSTRACTIt remains unknown whether H3K4 methylation, an epigenetic modification associated with gene activation, regulates fate determination of the postnatal neural stem and progenitor cells (NSCs and NPCs, or NSPCs). Here we show that the Dpy30 subunit of the major H3K4 methyltransferase complexes is preferentially expressed at a high level in NSCs and NPCs. By genetically inactivating Dpy30 in specific regions of mouse brain, we demonstrate a crucial role of efficient H3K4 methylation in maintaining both the self-renewal and differentiation capacity of postnatal NSPCs. Dpy30 inactivation results in deficiency in global H3K4 methylation, and disrupts development of hippocampus and especially the dentate gyrus and subventricular zone, the major regions for postnatal NSC activities. By in vitro assays on neurospheres from mouse brains as well as human and mouse NPCs, we show that Dpy30 is indispensable for sustaining the self-renewal and proliferation of NSPCs in a cell-intrinsic manner, and also enables the differentiation of mouse and human NPCs to neuronal and glial lineages. Dpy30 directly regulates H3K4 methylation and the induction of several genes critical in neurogenesis. These findings link a prominent epigenetic mechanism of gene expression to the fundamental properties of NSPCs, and may have implications in neurodevelopmental disorders.SIGNIFICANCE STATEMENTAs a highly prominent epigenetic mark that is associated with gene activation and a number of neurodevelopmental disorders in human, the role of histone H3K4 methylation in the fate determination of neural stem cells is unclear. Result of this study uncover a profound role of this epigenetic modification in the fundamental properties of postnatal neural stem cells, including self-renewal and differentiation, and may have implications for a better understanding and treatment of a broad spectrum of neurodevelopmental disorders associated with H3K4 methylation modulators.


2019 ◽  
Vol 3 (3) ◽  
pp. 419-431 ◽  
Author(s):  
Fang Dong ◽  
Haitao Bai ◽  
Xiaofang Wang ◽  
Shanshan Zhang ◽  
Zhao Wang ◽  
...  

Abstract The cell of origin, defined as the normal cell in which the transformation event first occurs, is poorly identified in leukemia, despite its importance in understanding of leukemogenesis and improving leukemia therapy. Although hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) were used for leukemia models, whether their self-renewal and differentiation potentials influence the initiation and development of leukemia is largely unknown. In this study, the self-renewal and differentiation potentials in 2 distinct types of HSCs (HSC1 [CD150+CD41−CD34−Lineage−Sca-1+c-Kit+ cells] and HSC2 [CD150−CD41−CD34−Lineage−Sca-1+c-Kit+ cells]) and 3 distinct types of HPCs (HPC1 [CD150+CD41+CD34−Lineage−Sca-1+c-Kit+ cells], HPC2 [CD150+CD41+CD34+Lineage−Sca-1+c-Kit+ cells], and HPC3 [CD150−CD41−CD34+Lineage−Sca-1+c-Kit+ cells]) were isolated from adult mouse bone marrow, and examined by competitive repopulation assay. Then, cells from each population were retrovirally transduced to initiate MLL-AF9 acute myelogenous leukemia (AML) and the intracellular domain of NOTCH-1 T-cell acute lymphoblastic leukemia (T-ALL). AML and T-ALL similarly developed from all HSC and HPC populations, suggesting multiple cellular origins of leukemia. New leukemic stem cells (LSCs) were also identified in these AML and T-ALL models. Notably, switching between immunophenotypical immature and mature LSCs was observed, suggesting that heterogeneous LSCs play a role in the expansion and maintenance of leukemia. Based on this mouse model study, we propose that acute leukemia arises from multiple cells of origin independent of the self-renewal and differentiation potentials in hematopoietic stem and progenitor cells and is amplified by LSC switchover.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Piergiorgio La Rosa ◽  
Pamela Bielli ◽  
Claudia Compagnucci ◽  
Eleonora Cesari ◽  
Elisabetta Volpe ◽  
...  

The balance between self-renewal and differentiation of neural progenitor cells (NPCs) dictates neurogenesis and proper brain development. We found that the RNA- binding protein Sam68 (Khdrbs1) is strongly expressed in neurogenic areas of the neocortex and supports the self-renewing potential of mouse NPCs. Knockout of Khdrbs1 constricted the pool of proliferating NPCs by accelerating their cell cycle exit and differentiation into post-mitotic neurons. Sam68 function was linked to regulation of Aldh1a3 pre-mRNA 3'-end processing. Binding of Sam68 to an intronic polyadenylation site prevents its recognition and premature transcript termination, favoring expression of a functional enzyme. The lower ALDH1A3 expression and activity in Khdrbs1-/- NPCs results in reduced glycolysis and clonogenicity, thus depleting the embryonic NPC pool and limiting cortical expansion. Our study identifies Sam68 as a key regulator of NPC self-renewal and establishes a novel link between modulation of ALDH1A3 expression and maintenance of high glycolytic metabolism in the developing cortex.


Cancer Cell ◽  
2010 ◽  
Vol 17 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Rinath Jeselsohn ◽  
Nelson E. Brown ◽  
Lisa Arendt ◽  
Ina Klebba ◽  
Miaofen G. Hu ◽  
...  

Blood ◽  
2011 ◽  
Vol 117 (23) ◽  
pp. 6083-6090 ◽  
Author(s):  
Ann Dahlberg ◽  
Colleen Delaney ◽  
Irwin D. Bernstein

AbstractDespite progress in our understanding of the growth factors that support the progressive maturation of the various cell lineages of the hematopoietic system, less is known about factors that govern the self-renewal of hematopoietic stem and progenitor cells (HSPCs), and our ability to expand human HSPC numbers ex vivo remains limited. Interest in stem cell expansion has been heightened by the increasing importance of HSCs in the treatment of both malignant and nonmalignant diseases, as well as their use in gene therapy. To date, most attempts to ex vivo expand HSPCs have used hematopoietic growth factors but have not achieved clinically relevant effects. More recent approaches, including our studies in which activation of the Notch signaling pathway has enabled a clinically relevant ex vivo expansion of HSPCs, have led to renewed interest in this arena. Here we briefly review early attempts at ex vivo expansion by cytokine stimulation followed by an examination of our studies investigating the role of Notch signaling in HSPC self-renewal. We will also review other recently developed approaches for ex vivo expansion, primarily focused on the more extensively studied cord blood–derived stem cell. Finally, we discuss some of the challenges still facing this field.


PLoS ONE ◽  
2009 ◽  
Vol 4 (10) ◽  
pp. e7630 ◽  
Author(s):  
Dhruv Sareen ◽  
Erin McMillan ◽  
Allison D. Ebert ◽  
Brandon C. Shelley ◽  
Julie A. Johnson ◽  
...  

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