Cell-Cycle Regulation in Embryonic Stem Cells: Centrosomal Decisions on Self-Renewal

2010 ◽  
Vol 19 (11) ◽  
pp. 1663-1678 ◽  
Author(s):  
Zuzana Koledova ◽  
Alwin Krämer ◽  
Leona Raskova Kafkova ◽  
Vladimir Divoky
Cell Cycle ◽  
2016 ◽  
Vol 15 (21) ◽  
pp. 2931-2942 ◽  
Author(s):  
Areta M. Czerwinska ◽  
Joanna Nowacka ◽  
Magdalena Aszer ◽  
Sylwia Gawrzak ◽  
Karolina Archacka ◽  
...  

Biomedicines ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 397
Author(s):  
Cheuk Yiu Tenny Chung ◽  
Paulisally Hau Yi Lo ◽  
Kenneth Ka Ho Lee

BRISC and BRCA1-A complex member 2 (Babam2) plays an essential role in promoting cell cycle progression and preventing cellular senescence. Babam2-deficient fibroblasts show proliferation defect and premature senescence compared with their wild-type (WT) counterpart. Pluripotent mouse embryonic stem cells (mESCs) are known to have unlimited cell proliferation and self-renewal capability without entering cellular senescence. Therefore, studying the role of Babam2 in ESCs would enable us to understand the mechanism of Babam2 in cellular aging, cell cycle regulation, and pluripotency in ESCs. For this study, we generated Babam2 knockout (Babam2−/−) mESCs to investigate the function of Babam2 in mESCs. We demonstrated that the loss of Babam2 in mESCs leads to abnormal G1 phase retention in response to DNA damage induced by gamma irradiation or doxorubicin treatments. Key cell cycle regulators, CDC25A and CDK2, were found to be degraded in Babam2−/− mESCs following gamma irradiation. In addition, Babam2−/− mESCs expressed p53 strongly and significantly longer than in control mESCs, where p53 inhibited Nanog expression and G1/S cell cycle progression. The combined effects significantly reduced developmental pluripotency in Babam2−/− mESCs. In summary, Babam2 maintains cell cycle regulation and pluripotency in mESCs in response to induced DNA damage.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1349-1349
Author(s):  
Emmanuelle Passegue ◽  
Amy J. Wagers ◽  
Sylvie Giuriato ◽  
Wade C. Anderson ◽  
Irving L. Weissman

Abstract The blood is a perpetually renewing tissue seeded by a rare population of adult bone marrow hematopoietic stem cells (HSC). During steady-state hematopoiesis, the HSC population is relatively quiescent but constantly maintains a low numbers of cycling cells that differentiate to produce the various lineage of mature blood cells. However, in response to hematological stress, the entire HSC population can be recruited into cycle to self-renew and regenerate the blood-forming system. HSC proliferation is therefore highly adaptative and requires appropriate regulation of cell cycle progression to drive both differentiation-associated and self-renewal-associated proliferation, without depletion of the stem cell pool. Although the molecular events controlling HSC proliferation are still poorly understood, they are likely determined, at least in part, by regulated expression and/or function of components and regulators of the cell cycle machinery. Here, we demonstrate that the long-term self-renewing HSC (defined as Lin−/c-Kit+/Sca-1+/Thy1.1int/Flk2−) exists in two distinct states that are both equally important for their in vivo functions as stem cells: a numerically dominant quiescent state, which is critical for HSC function in hematopoietic reconstitution; and a proliferative state, which represents almost a fourth of this population and is essential for HSC functions in differentiation and self-renewal. We show that when HSC exit quiescence and enter G1 as a prelude to cell division, at least two critical events occur: first, during the G1 and subsequent S-G2/M phases, they temporarily lose efficient in vivo engraftment activity, while retaining in vitro differentiation potential; and second, they select the particular cell cycle proteins that are associated with specific developmental outcomes (self-renewal vs. differentiation) and developmental fates (myeloid vs. lymphoid). Together, these findings provide a direct link between HSC proliferation, cell cycle regulation and cell fate decisions that have critical implications for both the therapeutic use of HSC and the understanding of leukemic transformation.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6314 ◽  
Author(s):  
Miaoying Yu ◽  
Yinghui Wei ◽  
Kui Xu ◽  
Shasha Liu ◽  
Lei Ma ◽  
...  

Background Self-renewal and pluripotency are considered as unwavering features of embryonic stem cells (ESCs). How ESCs regulate the self-renewal and differentiation is a central question in development and regenerative medicine research. Epidermal growth factor receptor (EGFR) was identified as a critical regulator in embryonic development, but its role in the maintenance of ESCs is poorly understood. Methods Here, EGFR was disrupted by its specific inhibitor AG1478 in mouse ESCs (mESCs), and its self-renewal and pluripotency were characterized according to their proliferation, expression of pluripotency markers, embryoid body (EB) formation, and mRNA expression patterns. We also used another EGFR inhibitor (gefitinib) and RNA interference assay to rule out the possibility of non-specific effects of AG1478. Results EGFR inhibition by AG1478 treatment in mESCs markedly reduced cell proliferation, caused cell cycle arrest at G0/G1 phase, and altered protein expressions of the cell cycle regulatory genes (CDK2 (decreased 11.3%) and proliferating cell nuclear antigen (decreased 25.2%)). The immunoreactivities and protein expression of pluripotency factors (OCT4 (decreased 26.9%)) also dramatically decreased, while the differentiation related genes (GATA4 (increased 1.6-fold)) were up-regulated in mESCs after EGFR inhibition. Meanwhile, EGFR inhibition in mESCs disrupted EB formation, indicating its impaired pluripotency. Additionally, the effects observed by EGFR inhibition with another inhibitor gefitinib and siRNA were consistent with those observed by AG1478 treatment in mESCs. These effects were manifested in the decreased expression of proliferative and pluripotency-related genes and the increased expression of genes involved in differentiation. Moreover, RNA-seq analysis displayed that transcript profiling was changed significantly after EGFR inhibition by AG1478. A large number of differentially expressed genes were involved in cell cycle, apoptotic process, epigenetic modification, and metabolic process, which were related to self-renewal and pluripotency, confirming that EGFR deficiency impaired self-renewal and pluripotency in mESCs. Conclusions Taken together, our results demonstrated the importance of EGFR in guarding the stemness of mESCs.


Sign in / Sign up

Export Citation Format

Share Document