scholarly journals Laminin β2 Chain Regulates Cell Cycle Dynamics in the Developing Retina

2022 ◽  
Vol 9 ◽  
Author(s):  
Dmitri Serjanov ◽  
Galina Bachay ◽  
Dale D. Hunter ◽  
William J. Brunken
Keyword(s):  
Cell Cycle ◽  
Cell Fate ◽  
Critical Role ◽  
Laminin Receptor ◽  
Cell Cycle Exit ◽  
Cell Fate Decisions ◽  
M Phase ◽  
Cell Cycle Dynamics ◽  
Laminin Β2

Vertebrate retinal development follows a highly stereotyped pattern, in which the retinal progenitor cells (RPCs) give rise to all retinal types in a conserved temporal sequence. Ensuring the proper control over RPC cell cycle exit and re-entry is, therefore, crucially important for the generation of properly functioning retina. In this study, we demonstrate that laminins, indispensible ECM components, at the retinal surface, regulate the mechanisms determining whether RPCs generate proliferative or post-mitotic progeny. In vivo deletion of laminin β2 in mice resulted in disturbing the RPC cell cycle dynamics, and premature cell cycle exit. Specifically, the RPC S-phase is shortened, with increased numbers of cells present in its late stages. This is followed by an accelerated G2-phase, leading to faster M-phase entry. Finally, the M-phase is extended, with RPCs dwelling longer in prophase. Addition of exogenous β2-containing laminins to laminin β2-deficient retinal explants restored the appropriate RPC cell cycle dynamics, as well as S and M-phase progression, leading to proper cell cycle re-entry. Moreover, we show that disruption of dystroglycan, a laminin receptor, phenocopies the laminin β2 deletion cell cycle phenotype. Together, our findings suggest that dystroglycan-mediated ECM signaling plays a critical role in regulating the RPC cell cycle dynamics, and the ensuing cell fate decisions.

scholarly journals A novel Axin2 knock-in mouse model for visualization and lineage tracing of WNT/CTNNB1 responsive cells

2020 ◽  
Author(s):  
Anoeska Agatha Alida van de Moosdijk ◽  
Yorick Bernardus Cornelis van de Grift ◽  
Saskia Madelon Ada de Man ◽  
Amber Lisanne Zeeman ◽  
Renée van Amerongen
Keyword(s):  
Cell Fate ◽  
Mouse Strain ◽  
Critical Role ◽  
Lineage Tracing ◽  
Fluorescent Reporter ◽  
Cell Fate Decisions ◽  
Stem Cell Maintenance ◽  
Signaling Dynamics ◽  
Before And After

AbstractWnt signal transduction controls tissue morphogenesis, maintenance and regeneration in all multicellular animals. In mammals, the WNT/CTNNB1 (Wnt/β-catenin) pathway controls cell proliferation and cell fate decisions before and after birth. It plays a critical role at multiple stages of embryonic development, but also governs stem cell maintenance and homeostasis in adult tissues. However, it remains challenging to monitor endogenous WNT/CTNNB1 signaling dynamics in vivo. Here we report the generation and characterization of a new knock-in mouse strain that doubles as a fluorescent reporter and lineage tracing driver for WNT/CTNNB1 responsive cells. We introduced a multi-cistronic targeting cassette at the 3’ end of the universal WNT/CTNNB1 target gene Axin2. The resulting knock-in allele expresses a bright fluorescent reporter (3xNLS-SGFP2) and a doxycycline-inducible driver for lineage tracing (rtTA3). We show that the Axin2P2A-rtTA3-T2A-3xNLS-SGFP2 strain labels WNT/CTNNB1 cells at multiple anatomical sites during different stages of embryonic and postnatal development. It faithfully reports the subtle and dynamic changes in physiological WNT/CTNNB1 signaling activity that occur in vivo. We expect this mouse strain to be a useful resource for biologists who want to track and trace the location and developmental fate of WNT/CTNNB1 responsive stem cells in different contexts.Abstract Figure

scholarly journals Let-7 regulates cell cycle dynamics in the developing cerebral cortex and retina

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Corinne L. A. Fairchild ◽  
Simranjeet K. Cheema ◽  
Joanna Wong ◽  
Keiko Hino ◽  
Sergi Simó ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Fate ◽  
Cell Cycle Progression ◽  
Developmental Time ◽  
Neural Progenitors ◽  
Cycle Progression ◽  
Cell Fate Decisions ◽  
Cell Cycle Dynamics

Abstract In the neural progenitors of the developing central nervous system (CNS), cell proliferation is tightly controlled and coordinated with cell fate decisions. Progenitors divide rapidly during early development and their cell cycle lengthens progressively as development advances to eventually give rise to a tissue of the correct size and cellular composition. However, our understanding of the molecules linking cell cycle progression to developmental time is incomplete. Here, we show that the microRNA (miRNA) let-7 accumulates in neural progenitors over time throughout the developing CNS. Intriguingly, we find that the level and activity of let-7 oscillate as neural progenitors progress through the cell cycle by in situ hybridization and fluorescent miRNA sensor analyses. We also show that let-7 mediates cell cycle dynamics: increasing the level of let-7 promotes cell cycle exit and lengthens the S/G2 phase of the cell cycle, while let-7 knock down shortens the cell cycle in neural progenitors. Together, our findings suggest that let-7 may link cell proliferation to developmental time and regulate the progressive cell cycle lengthening that occurs during development.

Cell Cycle Regulation and Cell Fate Decisions in Hematopoietic Stem Cells.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1349-1349
Author(s):  
Emmanuelle Passegue ◽  
Amy J. Wagers ◽  
Sylvie Giuriato ◽  
Wade C. Anderson ◽  
Irving L. Weissman
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Cell Fate ◽  
Cell Cycle Regulation ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Cell Fate Decisions ◽  
Cycle Regulation

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.

scholarly journals Distinct mechanisms control genome recognition by p53 at its target genes linked to different cell fates

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Marina Farkas ◽  
Hideharu Hashimoto ◽  
Yingtao Bi ◽  
Ramana V. Davuluri ◽  
Lois Resnick-Silverman ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Binding ◽  
Cell Cycle Arrest ◽  
Cell Fate ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Binding Modes ◽  
Cell Fate Decisions ◽  
Cycle Arrest

AbstractThe tumor suppressor p53 integrates stress response pathways by selectively engaging one of several potential transcriptomes, thereby triggering cell fate decisions (e.g., cell cycle arrest, apoptosis). Foundational to this process is the binding of tetrameric p53 to 20-bp response elements (REs) in the genome (RRRCWWGYYYN0-13RRRCWWGYYY). In general, REs at cell cycle arrest targets (e.g. p21) are of higher affinity than those at apoptosis targets (e.g., BAX). However, the RE sequence code underlying selectivity remains undeciphered. Here, we identify molecular mechanisms mediating p53 binding to high- and low-affinity REs by showing that key determinants of the code are embedded in the DNA shape. We further demonstrate that differences in minor/major groove widths, encoded by G/C or A/T bp content at positions 3, 8, 13, and 18 in the RE, determine distinct p53 DNA-binding modes by inducing different Arg248 and Lys120 conformations and interactions. The predictive capacity of this code was confirmed in vivo using genome editing at the BAX RE to interconvert the DNA-binding modes, transcription pattern, and cell fate outcome.

scholarly journals Global analysis of proliferation and cell cycle gene expression in the regulation of hematopoietic stem and progenitor cell fates

2005 ◽  
Vol 202 (11) ◽  
pp. 1599-1611 ◽  
Author(s):  
Emmanuelle Passegué ◽  
Amy J. Wagers ◽  
Sylvie Giuriato ◽  
Wade C. Anderson ◽  
Irving L. Weissman
Keyword(s):  
Cell Cycle ◽  
Cell Fate ◽  
Progenitor Cell ◽  
Global Analysis ◽  
Molecular Networks ◽  
Proliferation Index ◽  
Cell Cycle Gene ◽  
Hematopoietic Stem ◽  
Cell Fate Decisions

Knowledge of the molecular networks controlling the proliferation and fate of hematopoietic stem cells (HSC) is essential to understand their function in maintaining blood cell production during normal hematopoiesis and upon clinical transplantation. Using highly purified stem and progenitor cell populations, we define the proliferation index and status of the cell cycle machinery at discrete stages of hematopoietic differentiation and during cytokine-mediated HSC mobilization. We identify distinct sets of cell cycle proteins that specifically associate with differentiation, self-renewal, and maintenance of quiescence in HSC and progenitor cells. Moreover, we describe a striking inequality of function among in vivo cycling and quiescent HSC by demonstrating that their long-term engraftment potential resides predominantly in the G0 fraction. These data provide a direct link between HSC proliferation and function and identify discrete molecular targets in regulating HSC cell fate decisions that could have implications for both the therapeutic use of HSC and the understanding of leukemic transformation.

Mastermind critically regulates Notch-mediated lymphoid cell fate decisions

Blood ◽  
2004 ◽  
Vol 104 (6) ◽  
pp. 1696-1702 ◽  
Author(s):  
Ivan Maillard ◽  
Andrew P. Weng ◽  
Andrea C. Carpenter ◽  
Carlos G. Rodriguez ◽  
Hong Sai ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Cell Fate ◽  
Critical Role ◽  
Family Members ◽  
Notch Pathway ◽  
Dominant Negative ◽  
Hematopoietic Stem ◽  
Cell Fate Decisions

Abstract During lymphoid development, Notch1 plays a critical role in the T-cell/B-cell lineage decision, while Notch2 is essential for marginal zone B-cell (MZB) development. Notch pathway activation induces translocation of intracellular Notch (ICN) to the nucleus, where it interacts with the transcription factor CSL (CBF1/RBP-Jk, Suppressor of Hairless, Lag-1). In vitro, ICN binds Mastermind-like proteins, which act as potent Notch coactivators. Three MAML family members (MAML1-3) have been identified in mammals, but their importance in vivo is unknown. To investigate the function of MAMLs in hematopoietic development, we introduced a dominant negative (DN) mutant of MAML1, capable of inhibiting Notch1-4, in murine hematopoietic stem cells. DNMAML1 resulted in early inhibition of T-cell development and the appearance of intrathymic B cells, phenotypes consistent with Notch1 inhibition. The T-cell differentiation block was as profound as that produced by enforced expression of the Notch modulator Deltex1. In DNMAML1-transduced spleen cells, a dramatic decrease in MZB cells was present, consistent with Notch2 inhibition. In contrast, Deltex1 did not decrease MZB cell numbers. These results suggest a critical role for MAMLs during Notch-mediated cell fate decisions in vivo and indicate that DNMAML1, but not Deltex1, can be used to interfere with the function of multiple Notch family members. (Blood. 2004;104:1696-1702)

scholarly journals The aryl hydrocarbon receptor controls cell-fate decisions in B cells

2016 ◽  
Vol 214 (1) ◽  
pp. 197-208 ◽  
Author(s):  
Bharat Vaidyanathan ◽  
Ashutosh Chaudhry ◽  
William T. Yewdell ◽  
Davide Angeletti ◽  
Wei-Feng Yen ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Aryl Hydrocarbon Receptor ◽  
Cell Fate ◽  
Plasma Cells ◽  
Ex Vivo ◽  
Critical Role ◽  
Cell Fate Decisions ◽  
Aryl Hydrocarbon

Generation of cellular heterogeneity is an essential feature of the adaptive immune system. This is best exemplified during humoral immune response when an expanding B cell clone assumes multiple cell fates, including class-switched B cells, antibody-secreting plasma cells, and memory B cells. Although each cell type is essential for immunity, their generation must be exquisitely controlled because a class-switched B cell cannot revert back to the parent isotype, and a terminally differentiated plasma cell cannot contribute to the memory pool. In this study, we show that an environmental sensor, the aryl hydrocarbon receptor (AhR) is highly induced upon B cell activation and serves a critical role in regulating activation-induced cell fate outcomes. We find that AhR negatively regulates class-switch recombination ex vivo by altering activation-induced cytidine deaminase expression. We further demonstrate that AhR suppresses class switching in vivo after influenza virus infection and immunization with model antigens. In addition, by regulating Blimp-1 expression via Bach2, AhR represses differentiation of B cells into plasmablasts ex vivo and antibody-secreting plasma cells in vivo. These experiments suggest that AhR serves as a molecular rheostat in B cells to brake the effector response, possibly to facilitate optimal recall responses. Thus, AhR might represent a novel molecular target for manipulation of B cell responses during vaccination.

scholarly journals Cell Cycle-Dependent Expression of Mammalian E2-C Regulated by the Anaphase-Promoting Complex/Cyclosome

2000 ◽  
Vol 11 (8) ◽  
pp. 2821-2831 ◽  
Author(s):  
Atsushi Yamanaka ◽  
Shigetsugu Hatakeyama ◽  
Kin-ichiro Kominami ◽  
Masatoshi Kitagawa ◽  
Masaki Matsumoto ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Substrate Specificity ◽  
Critical Role ◽  
Anaphase Promoting Complex ◽  
Polyubiquitin Chain ◽  
M Phase ◽  
Ubiquitin Conjugating Enzyme ◽  
Recognition Motifs ◽  
Cycle Dependent ◽  
Conjugating Enzyme

Progression through mitosis requires the precisely timed ubiquitin-dependent degradation of specific substrates. E2-C is a ubiquitin-conjugating enzyme that plays a critical role with anaphase-promoting complex/cyclosome (APC/C) in progression of and exit from M phase. Here we report that mammalian E2-C is expressed in late G2/M phase and is degraded as cells exit from M phase. The mammalian E2-C shows an autoubiquitinating activity leading to covalent conjugation to itself with several ubiquitins. The ubiquitination of E2-C is strongly enhanced by APC/C, resulting in the formation of a polyubiquitin chain. The polyubiquitination of mammalian E2-C occurs only when cells exit from M phase. Furthermore, mammalian E2-C contains two putative destruction boxes that are believed to act as recognition motifs for APC/C. The mutation of this motif reduced the polyubiquitination of mammalian E2-C, resulting in its stabilization. These results suggest that mammalian E2-C is itself a substrate of the APC/C-dependent proteolysis machinery, and that the periodic expression of mammalian E2-C may be a novel autoregulatory system for the control of the APC/C activity and its substrate specificity.

scholarly journals The LINC complex transmits integrin-dependent tension to the nuclear lamina and represses epidermal differentiation

2020 ◽  
Author(s):  
Emma Carley ◽  
Rachel K. Stewart ◽  
Abigail Zieman ◽  
Iman Jalilian ◽  
Diane. E. King ◽  
...  
Keyword(s):  
Cell Fate ◽  
Control Cell ◽  
Nuclear Lamina ◽  
Epidermal Differentiation ◽  
Keratinocyte Differentiation ◽  
Linc Complex ◽  
Force Transmission ◽  
Cell Fate Decisions

AbstractWhile the mechanisms by which chemical signals control cell fate have been well studied, how mechanical inputs impact cell fate decisions are not well understood. Here, using the well-defined system of keratinocyte differentiation in the skin, we examine whether and how direct force transmission to the nucleus regulates epidermal cell fate. Using a molecular biosensor, we find that tension on the nucleus through Linker of Nucleoskeleton and Cytoskeleton (LINC) complexes requires integrin engagement in undifferentiated epidermal stem cells, and is released during differentiation concomitant with decreased tension on A-type lamins. LINC complex ablation in mice reveals that LINC complexes are required to repress epidermal differentiation in vivo and in vitro and influence accessibility of epidermal differentiation genes, suggesting that force transduction from engaged integrins to the nucleus plays a role in maintaining keratinocyte progenitors. This work reveals a direct mechanotransduction pathway capable of relaying adhesion-specific signals to regulate cell fate.

scholarly journals Dual effect of 2-methoxyestradiol on cell cycle events in human osteosarcoma 143B cells.

2002 ◽  
Vol 49 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Justyna Gołebiewska ◽  
Piotr Rozwadowski ◽  
Jan Henryk Spodnik ◽  
Narcyz Knap ◽  
Takashi Wakabayashi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Growth Inhibitor ◽  
Cytotoxic Action ◽  
M Cell ◽  
Human Osteosarcoma ◽  
Cycle Arrest ◽  
M Phase ◽  
The Stability

We have demonstrated for the first time that the steroid metabolite, 2-methoxyestradiol (2-ME) is a powerful growth inhibitor of human osteosarcoma 143 B cell line by pleiotropic mechanisms involving cell cycle arrest at two different points and apoptosis. The ability of 2-ME to inhibit cell cycle at the respective points has been found concentration dependent. 1 microM 2-ME inhibited cell cycle at G1 phase while 10 microM 2-ME caused G2/M cell cycle arrest. As a natural estrogen metabolite 2-ME is expected to perturb the stability of microtubules (MT) in vivo analogously to Taxol--the MT binding anticancer agent. Contrary to 2-ME, Taxol induced accumulation of osteosarcoma cells in G2/M phase of cell cycle only. The presented data strongly suggest two different mechanisms of cytotoxic action of 2-ME at the level of a single cell.

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