Notch Signaling in Mammalian Intestinal Stem Cells: Determining Cell Fate and Maintaining Homeostasis

2019 ◽  
Vol 14 (7) ◽  
pp. 583-590 ◽  
Author(s):  
Shao-jie Liang ◽  
Xiang-guang Li ◽  
Xiu-qi Wang

: The intestine serves mainly as a place for digestion and absorption and functions as an immune and endocrine organ. Intestinal stem cells (ISCs) play critical roles in the maintenance of intestinal homeostasis and regeneration, and a complex of signaling pathways is involved in these processes. The Notch signaling pathway is induced via distinct cell-to-cell connections, which are activated through the binding of the Notch ligand on the surface of niche cells to the Notch receptor on ISCs. Numerous studies have shown the central importance of Notch signaling in the proliferation and differentiation of ISCs. Here, we summarize the latest research progress on the crucial functions of Notch signaling in maintaining homeostasis and determining the cell fate of ISCs. Furthermore, the challenges of Notch signaling in colon cancer therapy strategies are also discussed. Several important questions regarding Notch regulation of ISCs are proposed.

Biology Open ◽  
2021 ◽  
Vol 10 (11) ◽  
Author(s):  
Lin Shi ◽  
Ruiyan Kong ◽  
Zhengran Li ◽  
Hang Zhao ◽  
Rui Ma ◽  
...  

ABSTRACT Adult stem cells are critical for the maintenance of tissue homeostasis. However, how the proliferation and differentiation of intestinal stem cells (ISCs) are regulated remains not fully understood. Here, we find a mutant, stum 9-3, affecting the proliferation and differentiation of Drosophila adult ISCs in a forward genetic screen for factors regulating the proliferation and differentiation ISCs. stum 9-3 acts through the conserved Notch signaling pathway, upstream of the S2 cleavage of the Notch receptor. Interestingly, the phenotype of stum 9-3 mutant is not caused by disruption of stumble (stum), where the p-element is inserted. Detailed mapping, rescue experiments and mutant characterization show that stum 9-3 is a new allele of O-fucosyltransferase 1 (O-fut1). Our results indicate that unexpected mutants with interesting phenotype could be recovered in forward genetic screens using known p-element insertion stocks.


Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1879 ◽  
Author(s):  
Christian T. Meisel ◽  
Cristina Porcheri ◽  
Thimios A. Mitsiadis

The Notch signaling pathway regulates cell proliferation, cytodifferentiation and cell fate decisions in both embryonic and adult life. Several aspects of stem cell maintenance are dependent from the functionality and fine tuning of the Notch pathway. In cancer, Notch is specifically involved in preserving self-renewal and amplification of cancer stem cells, supporting the formation, spread and recurrence of the tumor. As the function of Notch signaling is context dependent, we here provide an overview of its activity in a variety of tumors, focusing mostly on its role in the maintenance of the undifferentiated subset of cancer cells. Finally, we analyze the potential of molecules of the Notch pathway as diagnostic and therapeutic tools against the various cancers.


1998 ◽  
Vol 18 (12) ◽  
pp. 7423-7431 ◽  
Author(s):  
Sophie Jarriault ◽  
Odile Le Bail ◽  
Estelle Hirsinger ◽  
Olivier Pourquié ◽  
Frédérique Logeat ◽  
...  

ABSTRACT The Notch receptor is involved in many cell fate determination events in vertebrates and invertebrates. It has been shown inDrosophila melanogaster that Delta-dependent Notch signaling activates the transcription factor Suppressor of Hairless, leading to an increased expression of the Enhancer of Splitgenes. Genetic evidence has also implicated the kuzbaniangene, which encodes a disintegrin metalloprotease, in the Notch signaling pathway. By using a two-cell coculture assay, we show here that vertebrate Dl-1 activates the Notch-1 cascade. Consistent with previous data obtained with active forms of Notch-1 aHES-1-derived promoter construct is transactivated in cells expressing Notch-1 in response to Dl-1 stimulation. Impairing the proteolytic maturation of the full-length receptor leads to a decrease in HES-1 transactivation, further supporting the hypothesis that only mature processed Notch is expressed at the cell surface and activated by its ligand. Furthermore, we observed that Dl-1-inducedHES-1 transactivation was dependent both on Kuzbanian and RBP-J activities, consistent with the involvement of these two proteins in Notch signaling in Drosophila. We also observed that exposure of Notch-1-expressing cells to Dl-1 results in an increased level of endogenous HES-1 mRNA. Finally, coculture of Dl-1-expressing cells with myogenic C2 cells suppresses differentiation of C2 cells into myotubes, as previously demonstrated for Jagged-1 and Jagged-2, and also leads to an increased level of endogenousHES-1 mRNA. Thus, Dl-1 behaves as a functional ligand for Notch-1 and has the same ability to suppress cell differentiation as the Jagged proteins do.


2012 ◽  
Vol 209 (4) ◽  
pp. 713-728 ◽  
Author(s):  
Keunwook Lee ◽  
Ki Taek Nam ◽  
Sung Hoon Cho ◽  
Prathyusha Gudapati ◽  
Yoonha Hwang ◽  
...  

Notch plays critical roles in both cell fate decisions and tumorigenesis. Notch receptor engagement initiates signaling cascades that include a phosphatidylinositol 3-kinase/target of rapamycin (TOR) pathway. Mammalian TOR (mTOR) participates in two distinct biochemical complexes, mTORC1 and mTORC2, and the relationship between mTORC2 and physiological outcomes dependent on Notch signaling is unknown. In this study, we report contributions of mTORC2 to thymic T-cell acute lymphoblastic leukemia (T-ALL) driven by Notch. Conditional deletion of Rictor, an essential component of mTORC2, impaired Notch-driven proliferation and differentiation of pre-T cells. Furthermore, NF-κB activity depended on the integrity of mTORC2 in thymocytes. Active Akt restored NF-κB activation, a normal rate of proliferation, and differentiation of Rictor-deficient pre-T cells. Strikingly, mTORC2 depletion lowered CCR7 expression in thymocytes and leukemic cells, accompanied by decreased tissue invasion and delayed mortality in T-ALL driven by Notch. Collectively, these findings reveal roles for mTORC2 in promoting thymic T cell development and T-ALL and indicate that mTORC2 is crucial for Notch signaling to regulate Akt and NF-κB.


2010 ◽  
Vol 30 (7) ◽  
pp. 1852-1863 ◽  
Author(s):  
Michael E. Engel ◽  
Hong N. Nguyen ◽  
Jolene Mariotti ◽  
Aubrey Hunt ◽  
Scott W. Hiebert

ABSTRACT The Notch signaling pathway regulates gene expression programs to influence the specification of cell fate in diverse tissues. In response to ligand binding, the intracellular domain of the Notch receptor is cleaved by the γ-secretase complex and then translocates to the nucleus. There, it binds the transcriptional repressor CSL, triggering its conversion to an activator of Notch target gene expression. The events that control this conversion are poorly understood. We show that the transcriptional corepressor, MTG16, interacts with both CSL and the intracellular domains of Notch receptors, suggesting a pivotal role in regulation of the Notch transcription complex. The Notch1 intracellular domain disrupts the MTG16-CSL interaction. Ex vivo fate specification in response to Notch signal activation is impaired in Mtg16 −/− hematopoietic progenitors, and restored by MTG16 expression. An MTG16 derivative lacking the binding site for the intracellular domain of Notch1 fails to restore Notch-dependent cell fate. These data suggest that MTG16 interfaces with critical components of the Notch transcription complex to affect Notch-dependent lineage allocation in hematopoiesis.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4287-4287
Author(s):  
Maria D. Cappellini ◽  
Ilaria V. Libani ◽  
Elisabetta Calzavara ◽  
Luisa Ronzoni ◽  
Raffaella Chiaramonte ◽  
...  

Abstract Hematopoiesis involves highly regulated proliferation and differentiation during which a small number of multipotent stem cells give rise to differentiated progenies. In several developmental systems stem cells fate is influenced by soluble molecules acting via cell-cell interaction, including those mediate by the Notch receptor family. Members of Notch family transmembrane receptors are found on primitive hematopoietic precursors, suggesting a role for Notch signaling in mammalian blood cells development. Notch signaling regulates cell fate controlling asymmetric cell division during stem/progenitor cell differentiation. A previous study on K562 cell line showed that Notch signaling inhibits erythroid/megakaryocytic development by suppressing GATA-1 activity. Furthermore there are evidences that Notch is expressed in early murine erythroid precursors. Probably Notch signaling in these uncommittted precursors may lead to enhanced survival, preserving multilineage potential. The role of Notch pathway during human adult erytropiesis has not been described. The aim of this study is to investigate the modulation of Notch activity during “in vitro” human erythropiesis. Human CD34+ from perpheral blood of normal adult subjects were differentiate “in vitro” for two weeks by the addiction of IL-3, SCF and Epo. This method of colture reproduces all stages of adult erythropoiesis. We analized the modulation of the expression of Notch-1, of its effector Hes-1 and of several erythoid specific genes, at different stages of differentiation using real time PCR. Our analysis shows that Hes-1 expression, which indicates the activation of Notch-1 pathway, is very high in the early steps of differentiation (BFU-E, CFU-E) while in the late stages rapidly decreases to undetectable levels. The Notch-1 gene expression doesn’t seem to be modulated way, but we didn’t invstigate the protein levels yet. These data suggest that Notch pathway is involved in the early stages of erythroid differentiation where it may enhance erythroid progenitors survival up to CFU-E, as hypothisized in mouse model, preventing them from apoptotic stimuli and promoting their proliferation. Involvement of Notch-1 signaling in preventing erythroid progenitors from apoptosis during erythroid differentiation could be important in some erythropoietic disorders such as b-Thalassemia syndromes or diserythropoietic anemias.


2005 ◽  
Vol 25 (21) ◽  
pp. 9503-9508 ◽  
Author(s):  
Shaolin Shi ◽  
Mark Stahl ◽  
Linchao Lu ◽  
Pamela Stanley

ABSTRACT The canonical Notch signaling pathway mediated by Delta- and Jagged-like Notch ligands determines a variety of cell fates in metazoa. In Caenorhabditis elegans and sea urchins, canonical Notch signaling is essential for different cell fate specifications during early embryogenesis or the formation of endoderm, mesoderm, or ectoderm germ layers. Transcripts of Notch signaling pathway genes are present during mouse blastogenesis, suggesting that the canonical Notch signaling pathway may also function in early mammalian development. To test this directly, we used conditional deletion in oocytes carrying a ZP3Cre recombinase transgene to generate mouse embryos lacking both maternal and zygotic protein O-fucosyltransferase 1, a cell-autonomous and essential component of canonical Notch receptor signaling. Homozygous mutant embryos derived from eggs lacking Pofut1 gene transcripts developed indistinguishably from the wild type until approximately embryonic day 8.0, a postgastrulation stage after the formation of the three germ layers. Thus, in contrast to the case with C. elegans and sea urchins, canonical Notch signaling is not required in mammals for earliest cell fate specifications or for formation of the three germ layers. The use of canonical Notch signaling for early cell fate specifications by lower organisms may represent co-option of a regulatory pathway originally used later in development by all metazoa.


2015 ◽  
Vol 210 (2) ◽  
pp. 303-318 ◽  
Author(s):  
Maria J. Gomez-Lamarca ◽  
Laura A. Snowdon ◽  
Ekatarina Seib ◽  
Thomas Klein ◽  
Sarah J. Bray

Notch signaling is a major regulator of cell fate, proliferation, and differentiation. Like other signaling pathways, its activity is strongly influenced by intracellular trafficking. Besides contributing to signal activation and down-regulation, differential fluxes between trafficking routes can cause aberrant Notch pathway activation. Investigating the function of the retromer-associated DNAJ protein Rme-8 in vivo, we demonstrate a critical role in regulating Notch receptor recycling. In the absence of Rme-8, Notch accumulated in enlarged tubulated Rab4-positive endosomes, and as a consequence, signaling was compromised. Strikingly, when the retromer component Vps26 was depleted at the same time, Notch no longer accumulated and instead was ectopically activated. Likewise, depletion of ESCRT-0 components Hrs or Stam in combination with Rme-8 also led to high levels of ectopic Notch activity. Together, these results highlight the importance of Rme-8 in coordinating normal endocytic recycling route and reveal that its absence predisposes toward conditions in which pathological Notch signaling can occur.


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