scholarly journals p63 sets the threshold for induction of apoptosis using a kinetically encoded ‘doorbell-like’ mechanism

2019 ◽  
Author(s):  
Jakob Gebel ◽  
Marcel Tuppi ◽  
Apirat Chaikuad ◽  
Katharina Hötte ◽  
Laura Schulz ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Fate ◽  
Reproductive Capacity ◽  
Structural Mechanism ◽  
Cell Fate Decisions ◽  
Cell Death Pathways ◽  
Induction Of Apoptosis ◽  
The Difference ◽  
The One

AbstractCell fate decisions such as apoptosis require cells to translate signaling input into a binary yes/no response. A tight control of the process is required to avoid loss of cells by accidental activation of cell death pathways. One particularly critical situation exists in primary oocytes because their finite number determines the reproductive capacity of females. On the one hand a stringent genetic quality control is necessary to maintain the genetic integrity of the entire species; on the other hand an overly stringent mechanism that kills oocytes with even minor DNA damage can deplete the whole primary oocyte pool leading to infertility. The p53 homolog TAp63α is the key regulator of genome integrity in oocytes. After DNA damage TAp63α is activated by multistep phosphorylation involving multiple phosphorylation events by the kinase CK1, which triggers the transition from a dimeric and inactive conformation to an open and active tetramer. By measuring activation kinetics in ovaries and single site phosphorylation kineticsin vitrowith peptides and full length protein we show that TAp63α phosphorylation follows a biphasic behavior. While the first two CK1 phosphorylation events are fast, the third one that constitutes the decisive step to form the active conformation is slow. We reveal the structural mechanism for the difference in the kinetic behavior based on an unusual CK1/TAp63α substrate interaction and demonstrate by quantitative simulation that the slow phosphorylation phase determines the threshold of DNA damage required for induction of apoptosis.

scholarly journals Cellular senescence is a central response to cytotoxic chemotherapy in high-grade serous ovarian cancer

2018 ◽  
Author(s):  
L. Calvo ◽  
S. Cheng ◽  
M. Skulimowski ◽  
I. Clément ◽  
L. Portelance ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Dna Damage ◽  
Cell Fate ◽  
Cellular Senescence ◽  
Response To Treatment ◽  
High Grade ◽  
Serous Ovarian Cancer ◽  
Cell Fate Decisions ◽  
Response To Chemotherapy

AbstractHigh-grade serous ovarian cancer (HGSOC) commonly responds to initial therapy, but this response is rarely durable. Understanding cell fate decisions taken by HGSOC cells in response to treatment could guide new therapeutic opportunities. Here we find that primary HGSOC cultures undergo therapy-induced senescence (TIS) in response to DNA damage induced by chemotherapy. HGSOC-TIS displays most senescence hallmarks including persistent DNA damage, senescence-associated inflammatory secretome, and selective sensitivity to senolytic Bcl-2 family inhibitors, suggesting avenues for preferential synergistic clearance of these cells. Comparison of pre- and post-chemotherapy HGSOC patient tissue samples revealed changes in senescence biomarkers suggestive of post-treatment “in patient” TIS, and a stronger TIS response in post-chemotherapy tissues correlated with better 5-year survival rates for patients. Together, these data suggest that the induction of cellular senescence in HGSOC cells accounts at least in part for beneficial cellular responses to treatment in patients providing a new therapeutic target.One Sentence SummaryCellular senescence is a central beneficial response to chemotherapy in high-grade serous ovarian cancer bothin vitroand in patient.

scholarly journals Context-dependent roles of YAP/TAZ in stem cell fates and cancer

2021 ◽  
Author(s):  
Lucy LeBlanc ◽  
Nereida Ramirez ◽  
Jonghwan Kim
Keyword(s):  
Stem Cell ◽  
Cell Fate ◽  
Control Cell ◽  
Substantial Portion ◽  
Cell Fates ◽  
Cell Fate Decisions ◽  
Cell Death Pathways ◽  
Multiple Context ◽  
Cancer Cell Survival ◽  
Context Dependent

AbstractHippo effectors YAP and TAZ control cell fate and survival through various mechanisms, including transcriptional regulation of key genes. However, much of this research has been marked by conflicting results, as well as controversy over whether YAP and TAZ are redundant. A substantial portion of the discordance stems from their contradictory roles in stem cell self-renewal vs. differentiation and cancer cell survival vs. apoptosis. In this review, we present an overview of the multiple context-dependent functions of YAP and TAZ in regulating cell fate decisions in stem cells and organoids, as well as their mechanisms of controlling programmed cell death pathways in cancer.

scholarly journals New inhibitors of glucosylceramide synthase and their effect on cell fate

2014 ◽  
Vol 7 (2) ◽  
pp. 99-104 ◽  
Author(s):  
Katarína Turáková ◽  
Boris Lakatoš ◽  
Andrej Ďuriš ◽  
Daniela Moravčíková ◽  
Dušan Berkeš
Keyword(s):  
Cell Viability ◽  
Cell Fate ◽  
Calcium Transport ◽  
Large Scale ◽  
Process Development ◽  
Pharmaceutical Research ◽  
Pathological Process ◽  
Uridine Diphosphate ◽  
Induction Of Apoptosis

Abstract Glucosylceramide (GlcCer) is an essential glycosylated lipid found in organisms ranging from fungi to mammals. It is composed of a hydrophilic β-linked glucose and a hydrophobic ceramide, with a predominant content of sphingosine in mammals (d18:1). GlcCer is the precursor of a large scale of different glycosphingolipids. This cerebrozide is synthesized from uridine diphosphate-glucose and ceramide by a GlcCer synthase (UDP-glucose:ceramide glucosyltransferase; UGCG, EC 2.4.1.80). GlcCer-based sphingolipids have been identified as important mediators of a variety of cellular functions and their disequilibrium leads to pathological process development and may induce several diseases progression. Therefore, design of UGCG inhibitor represents an important topic for pharmaceutical research. In this paper, we aimed to study effects of newly synthesized derivatives of (±)-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol (PPMP, known UGCG inhibitor) on: i) activity of UGCG in vitro; ii) thymocytes viability; iii) calcium transport through plasma membrane of thymocytes; iv) induction of apoptosis and autophagy in thymocytes. Thymocytes were isolated from thymus of three to seven weeks old mice (ICR strain). The key factors influencing the effect of PPMP analogues were their concentration, chemical structure and incubation time. Derivatives were able to change Ca2+ transport already after 15 min of cultivation, but their effects on cell viability were manifested at least after 12 h of cultivation. Four from fifteen studied compounds affected UGCG activity after four hour lasting cultivation, - but without correlation with data relating to effects on calcium transport and/or cell viability. Most potent UGCG inhibitor was chosen and applied for induction of apoptosis and autophagy in thymocytes. This inhibitor induced typical DNA fragmentation and upregulation of LC3B protein as autophagy marker, after 2 h and 4 h cultivation, respectively.

scholarly journals Truncated mammalian Notch1 activates CBF1/RBPJk-repressed genes by a mechanism resembling that of Epstein-Barr virus EBNA2.

1996 ◽  
Vol 16 (3) ◽  
pp. 952-959 ◽  
Author(s):  
J J Hsieh ◽  
T Henkel ◽  
P Salmon ◽  
E Robey ◽  
M G Peterson ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cell Fate ◽  
Transcriptional Repression ◽  
Epstein Barr Virus ◽  
Cell Fate Decisions ◽  
Barr Virus ◽  
Amino Acid Region ◽  
Nuclear Events ◽  
Epstein Barr

The Notch/Lin-12/Glp-1 receptor family participates in cell-cell signaling events that influence cell fate decisions. Although several Notch homologs and receptor ligands have been identified, the nuclear events involved in this pathway remain incompletely understood. A truncated form of Notch, consisting only of the intracellular domain (NotchIC), localizes to the nucleus and functions as an activated receptor. Using both an in vitro binding assay and a cotransfection assay based on the two-hybrid principle, we show that mammalian NotchIC interacts with the transcriptional repressor CBF1, which is the human homolog of Drosophila Suppressor of Hairless. Cotransfection assays using segments of mouse NotchIC and CBF1 demonstrated that the N-terminal 114-amino-acid region of mouse NotchIC contains the CBF1 interactive domain and that the cdc10/ankyrin repeats are not essential for this interaction. This result was confirmed in immunoprecipation assays in which the N-terminal 114-amino-acid segment of NotchIC, but not the ankyrin repeat region, coprecipitated with CBF1. Mouse NotchIC itself is targeted to the transcriptional repression domain (aa179 to 361) of CBF1. Furthermore, transfection assays in which mouse NotchIC was targeted through Gal4-CBF1 or through endogenous cellular CBF1 indicated that NotchIC transactivates gene expression via CBF1 tethering to DNA. Transactivation by NotchIC occurs partially through abolition of CBF1-mediated repession. This same mechanism is used by Epstein-Barr virus EBNA2. Thus, mimicry of Notch signal transduction is involved in Epstein-Barr virus-driven immortalization.

scholarly journals SyNPL: Synthetic Notch pluripotent cell lines to monitor and manipulate cell interactions in vitro and in vivo

2021 ◽  
Author(s):  
Mattias Malaguti ◽  
Rosa Portero Migueles ◽  
Jennifer Annoh ◽  
Daina Sadurska ◽  
Guillaume Blin ◽  
...  
Keyword(s):  
Cell Fate ◽  
Cell Lines ◽  
Modular Design ◽  
Cell Interactions ◽  
Cell Populations ◽  
Cell Contact ◽  
Pluripotent Cells ◽  
Cell Fate Decisions ◽  
Cell Cell

ABSTRACTCell-cell interactions govern differentiation and cell competition in pluripotent cells during early development, but the investigation of such processes is hindered by a lack of efficient analysis tools. Here we introduce SyNPL: clonal pluripotent stem cell lines which employ optimised Synthetic Notch (SynNotch) technology to report cell-cell interactions between engineered “sender” and “receiver” cells in cultured pluripotent cells and chimaeric mouse embryos. A modular design makes it straightforward to adapt the system for programming differentiation decisions non-cell-autonomously in receiver cells in response to direct contact with sender cells. We demonstrate the utility of this system by enforcing neuronal differentiation at the boundary between two cell populations. In summary, we provide a new tool which could be used to identify cell interactions and to profile changes in gene or protein expression that result from direct cell-cell contact with defined cell populations in culture and in early embryos, and which can be adapted to generate synthetic patterning of cell fate decisions.

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 Estrogen Signaling Drives Ciliogenesis in Human Endometrial Organoids

Endocrinology ◽  
2019 ◽  
Vol 160 (10) ◽  
pp. 2282-2297 ◽  
Author(s):  
Sandra Haider ◽  
Magdalena Gamperl ◽  
Thomas R Burkard ◽  
Victoria Kunihs ◽  
Ulrich Kaindl ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Expression Patterns ◽  
Estrogen Signaling ◽  
Ciliated Cells ◽  
Cell Fate Decisions ◽  
Primary Driver ◽  
Endometrial Epithelium ◽  
Cyclic Changes

Abstract The human endometrium is the inner lining of the uterus consisting of stromal and epithelial (secretory and ciliated) cells. It undergoes a hormonally regulated monthly cycle of growth, differentiation, and desquamation. However, how these cyclic changes control the balance between secretory and ciliated cells remains unclear. Here, we established endometrial organoids to investigate the estrogen (E2)-driven control of cell fate decisions in human endometrial epithelium. We demonstrate that they preserve the structure, expression patterns, secretory properties, and E2 responsiveness of their tissue of origin. Next, we show that the induction of ciliated cells is orchestrated by the coordinated action of E2 and NOTCH signaling. Although E2 is the primary driver, inhibition of NOTCH signaling provides a permissive environment. However, inhibition of NOTCH alone is not sufficient to trigger ciliogenesis. Overall, we provide insights into endometrial biology and propose endometrial organoids as a robust and powerful model for studying ciliogenesis in vitro.

Runx1 Is Required for Notch-Induced Specification of Megakaryocyte Development from Early Hematopoietic Stem and Progenitor Cells

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1370-1370
Author(s):  
Melanie G Cornejo ◽  
Thomas Mercher ◽  
Joseph D. Growney ◽  
Jonathan Jesneck ◽  
Ivan Maillard ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Stromal Cells ◽  
Gfp Expression ◽  
Hematopoietic Stem ◽  
Cell Fate Decisions ◽  
Insight Into ◽  
Megakaryocyte Differentiation

Abstract The Notch signaling pathway is involved in a broad spectrum of cell fate decisions during development, and in the hematopoietic system, it is known to favor T cell- vs B cell lineage commitment. However, its role in myeloid lineage development is less well understood. We have shown, using heterotypic co-cultures of murine primary hematopoietic stem cells (Lin-Sca-1+ckit+ HSCs) and OP9 stromal cells expressing the Notch ligand Delta1 (OP9-DL1), that Notch signaling derived from cell non-autonomous cues acts as a positive regulator of megakaryocyte fate from LSK cells. Bone marrow transplantation experiments with a constitutively active Notch mutant resulted in enhanced megakaryopoiesis in vivo, with increased MEP numbers and megakaryocyte colony formation. In contrast, expression of dnMAML using a conditional ROSA26 knock-in mouse model significantly impaired megakaryopoiesis in vivo, with a marked decrease in megakaryocyte progenitors. In order to understand the cellular differentiation pathways controlled by Notch, we first examined the ability of various purified progenitor populations to differentiate toward megakaryocytes upon Notch stimulation in vitro. We observed that CMP and MEP, but not GMP, can engage megakaryopoiesis upon Notch stimulation. Our results were consistent with expression analysis of Notch signaling genes in these purified progenitors and were supported by the observation that transgenic Notch reporter mice display higher levels of reporter (i.e. GFP) expression in HSC and MEP, vs. CMP and GMP in vivo. Furthermore, purified progenitors with high GFP expression gave rise to increased numbers of megakarocyte-containing colonies when plated in vitro compared to GFP-negative progenitors. In addition, further purification of the HSC population into long-term (LT), short-term (ST), and lymphoid-primed myeloid progenitors (LMPP) before plating on OP9-DL1 stroma showed that LMPP have a reduced ability to give rise to megakaryocytes compared to the other two populations. These data support the hypothesis that there is an early commitment to erythro/megakaryocytic fate from HSC prior to lymphoid commitment. To gain insight into the molecular mechanism underlying Notch-induced megakaryopoiesis, we performed global gene expression analysis that demonstrated the engagement of a megakaryopoietic transcriptional program when HSC were co-cultured with OP9-DL1 vs. OP9 stroma or OP9-DL1 treated with gamma-secretase inhibitor. Of interest, Runx1 was among the most upregulated genes in HSC co-cultured on OP9-DL1 stroma. To assess whether Notch signaling engages megakaryocytic fate through induction of Runx1, we plated HSC from Runx1 −/− mice on OP9-DL1 stroma. Compared to WT cells, Runx1 −/− HSC had a severely reduced ability to develop into CD41+ cells. In contrast, overexpression of Runx1 in WT HSC was sufficient to induce megakaryocyte fate on OP9 stroma without Notch stimulation. Together, our results indicate that Notch pathway activation induced by stromal cells is an important regulator of cell fate decisions in early progenitors. We show that Notch signaling is upstream of Runx1 during Notch-induced megakaryocyte differentiation and that Runx1 is an essential target of Notch signaling. We believe that these results provide important insight into the pathways controlling megakaryocyte differentiation, and may have important therapeutic potential for megakaryocyte lineage-related disorders.

scholarly journals Reconstruction of rat retinal progenitor cell lineages in vitro reveals a surprising degree of stochasticity in cell fate decisions

Development ◽  
2010 ◽  
Vol 138 (2) ◽  
pp. 227-235 ◽  
Author(s):  
F. L. A. F. Gomes ◽  
G. Zhang ◽  
F. Carbonell ◽  
J. A. Correa ◽  
W. A. Harris ◽  
...  
Keyword(s):  
Cell Fate ◽  
Progenitor Cell ◽  
Retinal Progenitor Cell ◽  
Cell Fate Decisions ◽  
Cell Lineages ◽  
Retinal Progenitor

scholarly journals Activated Notch4 Inhibits Angiogenesis: Role of β1-Integrin Activation

2002 ◽  
Vol 22 (8) ◽  
pp. 2830-2841 ◽  
Author(s):  
Kevin G. Leong ◽  
Xiaolong Hu ◽  
Linheng Li ◽  
Michela Noseda ◽  
Bruno Larrivée ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Fate ◽  
Chorioallantoic Membrane ◽  
Surface Expression ◽  
Cell Phenotype ◽  
Β1 Integrin ◽  
Cell Fate Decisions ◽  
Β1 Integrins

ABSTRACT Notch4 is a member of the Notch family of transmembrane receptors that is expressed primarily on endothelial cells. Activation of Notch in various cell systems has been shown to regulate cell fate decisions. The sprouting of endothelial cells from microvessels, or angiogenesis, involves the modulation of the endothelial cell phenotype. Based on the function of other Notch family members and the expression pattern of Notch4, we postulated that Notch4 activation would modulate angiogenesis. Using an in vitro endothelial-sprouting assay, we show that expression of constitutively active Notch4 in human dermal microvascular endothelial cells (HMEC-1) inhibits endothelial sprouting. We also show that activated Notch4 inhibits vascular endothelial growth factor (VEGF)-induced angiogenesis in the chick chorioallantoic membrane in vivo. Activated Notch4 does not inhibit HMEC-1 proliferation or migration through fibrinogen. However, migration through collagen is inhibited. Our data show that Notch4 cells exhibit increased β1-integrin-mediated adhesion to collagen. HMEC-1 expressing activated Notch4 do not have increased surface expression of β1-integrins. Rather, we demonstrate that Notch4-expressing cells display β1-integrin in an active, high-affinity conformation. Furthermore, using function-activating β1-integrin antibodies, we demonstrate that activation of β1-integrins is sufficient to inhibit VEGF-induced endothelial sprouting in vitro and angiogenesis in vivo. Our findings suggest that constitutive Notch4 activation in endothelial cells inhibits angiogenesis in part by promoting β1-integrin-mediated adhesion to the underlying matrix.

Sign in / Sign up

Export Citation Format

Share Document