scholarly journals Numb regulates the balance between Notch recycling and late-endosome targeting inDrosophilaneural progenitor cells

2016 ◽  
Vol 27 (18) ◽  
pp. 2857-2866 ◽  
Author(s):  
Seth A. Johnson ◽  
Diana Zitserman ◽  
Fabrice Roegiers

The Notch signaling pathway plays essential roles in both animal development and human disease. Regulation of Notch receptor levels in membrane compartments has been shown to affect signaling in a variety of contexts. Here we used steady-state and pulse-labeling techniques to follow Notch receptors in sensory organ precursor cells in Drosophila. We find that the endosomal adaptor protein Numb regulates levels of Notch receptor trafficking to Rab7-labeled late endosomes but not early endosomes. Using an assay we developed that labels different pools of Notch receptors as they move through the endocytic system, we show that Numb specifically suppresses a recycled Notch receptor subpopulation and that excess Notch signaling in numb mutants requires the recycling endosome GTPase Rab11 activity. Our data therefore suggest that Numb controls the balance between Notch receptor recycling and receptor targeting to late endosomes to regulate signaling output after asymmetric cell division in Drosophila neural progenitors.

2013 ◽  
Vol 201 (3) ◽  
pp. 439-448 ◽  
Author(s):  
Alok Upadhyay ◽  
Vasundhara Kandachar ◽  
Diana Zitserman ◽  
Xin Tong ◽  
Fabrice Roegiers

In Drosophila peripheral neurogenesis, Notch controls cell fates in sensory organ precursor (SOP) cells. SOPs undergo asymmetric cell division by segregating Numb, which inhibits Notch signaling, into the pIIb daughter cell after cytokinesis. In contrast, in the pIIa daughter cell, Notch is activated and requires Sanpodo, but its mechanism of action has not been elucidated. As Sanpodo is present in both pIIa and pIIb cells, a second role for Sanpodo in regulating Notch signaling in the low-Notch pIIb cell has been proposed. Here we demonstrate that Sanpodo regulates Notch signaling levels in both pIIa and pIIb cells via distinct mechanisms. The interaction of Sanpodo with Presenilin, a component of the γ-secretase complex, was required for Notch activation and pIIa cell fate. In contrast, Sanpodo suppresses Notch signaling in the pIIb cell by driving Notch receptor internalization. Together, these results demonstrate that a single protein can regulate Notch signaling through distinct mechanisms to either promote or suppress signaling depending on the local cellular context.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Susana López-López ◽  
Eva María Monsalve ◽  
María José Romero de Ávila ◽  
Julia González-Gómez ◽  
Natalia Hernández de León ◽  
...  

Abstract Macrophage activation by Toll receptors is an essential event in the development of the response against pathogens. NOTCH signaling pathway is involved in the control of macrophage activation and the inflammatory processes. In this work, we have characterized NOTCH signaling in macrophages activated by Toll-like receptor (TLR) triggering and determined that DLL1 and DLL4 are the main ligands responsible for NOTCH signaling. We have identified ADAM10 as the main protease implicated in NOTCH processing and activation. We have also observed that furin, which processes NOTCH receptors, is induced by TLR signaling in a NOTCH-dependent manner. NOTCH3 is the only NOTCH receptor expressed in resting macrophages. Its expression increased rapidly in the first hours after TLR4 activation, followed by a gradual decrease, which was coincident with an elevation of the expression of the other NOTCH receptors. All NOTCH1, 2 and 3 contribute to the increased NOTCH signaling detected in activated macrophages. We also observed a crosstalk between NOTCH3 and NOTCH1 during macrophage activation. Finally, our results highlight the relevance of NOTCH3 in the activation of NF-κB, increasing p65 phosphorylation by p38 MAP kinase. Our data identify, for the first time, NOTCH3 as a relevant player in the control of inflammation.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 309
Author(s):  
Wataru Saiki ◽  
Chenyu Ma ◽  
Tetsuya Okajima ◽  
Hideyuki Takeuchi

The 100th anniversary of Notch discovery in Drosophila has recently passed. The Notch is evolutionarily conserved from Drosophila to humans. The discovery of human-specific Notch genes has led to a better understanding of Notch signaling in development and diseases and will continue to stimulate further research in the future. Notch receptors are responsible for cell-to-cell signaling. They are activated by cell-surface ligands located on adjacent cells. Notch activation plays an important role in determining the fate of cells, and dysregulation of Notch signaling results in numerous human diseases. Notch receptors are primarily activated by ligand binding. Many studies in various fields including genetics, developmental biology, biochemistry, and structural biology conducted over the past two decades have revealed that the activation of the Notch receptor is regulated by unique glycan modifications. Such modifications include O-fucose, O-glucose, and O-N-acetylglucosamine (GlcNAc) on epidermal growth factor-like (EGF) repeats located consecutively in the extracellular domain of Notch receptors. Being fine-tuned by glycans is an important property of Notch receptors. In this review article, we summarize the latest findings on the regulation of Notch activation by glycosylation and discuss future challenges.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Masaharu Yoshihara ◽  
Teppei Nishino ◽  
Manoj Kumar Yadav ◽  
Akihiro Kuno ◽  
Takeshi Nagata ◽  
...  

Abstract Objective The Delta-Notch signaling pathway induces fine-grained patterns of differentiation from initially homogeneous progenitor cells in many biological contexts, including Drosophila bristle formation, where mathematical modeling reportedly suggests the importance of production rate of the components of this signaling pathway. In contrast, the epithelial differentiation of bile ducts in the developing liver is unique in that it occurs around the portal vein cells, which express extremely high amounts of Delta ligands and act as a disturbance for the amount of Delta ligands in the field by affecting the expression levels of downstream target genes in the cells nearby. In the present study, we mathematically examined the dynamics of the Delta-Notch signaling pathway components in disturbance-driven biliary differentiation, using the model for fine-grained patterns of differentiation. Results A portal vein cell induced a high Notch signal in its neighboring cells, which corresponded to epithelial differentiation, depending on the production rates of Delta ligands and Notch receptors. In addition, this epithelial differentiation tended to occur in conditions where fine-grained patterning was reported to be lacking. These results highlighted the potential importance of the stability towards homogeneity determined by the production rates in Delta ligands and Notch receptors, in a disturbance-dependent epithelial differentiation.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 226.3-226
Author(s):  
M. Filipović ◽  
A. Šućur ◽  
D. Flegar ◽  
Z. Jajić ◽  
M. Ikić Matijašević ◽  
...  

Background:Osteoclasts mediate periarticular and systemic bone loss in rheumatoid arthritis (RA). Osteoclast progenitor cells (OCPs) derived from the myeloid lineage are susceptible to regulation through Notch signaling. Murine bone marrow and splenic OCPs, identified as CD45+Ly6G-CD3-B220-NK1.1-CD11blo/+CD115+CCR2+ cells, are specifically increased in arthritis. We previously identified an increased frequency of OCPs expressing Notch receptors in arthritic mice.Objectives:Several studies suggested that Notch signaling modulation affects the course of experimental arthritis. We aimed to determine the effects of Notch receptor signaling inhibition on OCP activity and arthritis severity in murine collagen-induced arthritis (CIA).Methods:Male C57/Bl6 and DBA mice were immunized with chicken type II collagen and treated with i.p. injections of anti-Notch 1 neutralizing antibodies (1mg/kg). Notch receptor 1 through 4 expression on OCPs was analyzed by flow cytometry in periarticular bone marrow (PBM) and spleen (SPL). Gene expression of Notch receptors, ligands and transcription targets as well as osteoclast differentiation genes RANK, cFos and cFms was determined by qPCR from tissues and sorted OCPs. FACS sorted OCPs were stimulated by osteoclastogenic factors (M-CSF and RANKL), in control, IgG, Jagged (Jag)1 or Delta-like (DLL)1 coated wells, with or without anti-Notch 1 antibodies. Research was approved by the Ethics Committee.Results:We confirmed the expression of Notch receptors on OCPs by flow cytometry with Notch 1 and 2 being most abundantly expressed (around 25% and 40% positive OCPs in PBM and 35% and 20% in SPL respectively), with a significant increase of Notch 2 expression in arthritis. Seeding OCPs on DLL1 coated wells significantly increased while seeding on Jag1 coated wells significantly decreased osteoclastogenesis as reflected on the number of TRAP+ osteoclasts and expression of osteoclast differentiation genes. The addition of anti-Notch 1 antibodies to ligand-stimulated OCPs resulted in an increased number of TRAP+ osteoclasts, partially reversing Jag1 inhibition. In vivo treatment with anti-Notch 1 antibodies did not affect total OCP frequency, but increased expression of Notch 4 both in PBM and SPL as seen by flow cytometry and qPCR. Additionally, anti-Notch 1 treatment stimulated Notch transcription factors HES and HEY. Both PBM and SPL cultured OCPs from anti-Notch 1 treated mice produced a higher number of large TRAP+ osteoclasts, doubling the area covered with osteoclasts in the latter compared to untreated mice. Increased osteoclastogenesis in vitro was further confirmed by an increased expression of osteoclast differentiation genes in the treated group.Conclusion:Our results confirm that Notch signaling may represent an important therapeutic target for the regulation of osteoclast activity in arthritis. Both in vitro and in vivo anti-Notch 1 neutralizing antibodies enhanced osteoclastogenesis in CIA model, implying an inhibitory role of Notch 1 signaling in osteoclast differentiation. As Notch 2 expression is increased on OCPs of arthritic mice, we next plan to determine the effects of Notch 2 neutralization on osteoclast activity and arthritis severity.References:[1]Ikić Matijašević M, Flegar D, Kovačić N, Katavić V, Kelava T, Šućur A, et al. Increased chemotaxis and activity of circulatory myeloid progenitor cells may contribute to enhanced osteoclastogenesis and bone loss in the C57BL/6 mouse model of collagen-induced arthritis. Clin Exp Immunol. 2016;186(3):321–35.[2]Šućur A, Filipović M, Flegar D, Kelava T, Šisl D, Lukač N, et al. Notch receptors and ligands in inflammatory arthritis – a systematic review. Immunology Letters 2020 Vol. 223, p. 106–14.Acknowledgements:The work has been supported by Croatian Science Foundation projects IP-2018-01-2414, UIP-2017-05-1965 and DOK-2018-09-4276.Disclosure of Interests:None declared.


Development ◽  
1999 ◽  
Vol 126 (17) ◽  
pp. 3925-3935 ◽  
Author(s):  
P. Beatus ◽  
J. Lundkvist ◽  
C. Oberg ◽  
U. Lendahl

The Notch signaling pathway is important for cellular differentiation. The current view is that the Notch receptor is cleaved intracellularly upon ligand activation. The intracellular Notch domain then translocates to the nucleus, binds to Suppressor of Hairless (RBP-Jk in mammals), and acts as a transactivator of Enhancer of Split (HES in mammals) gene expression. In this report we show that the Notch 3 intracellular domain (IC), in contrast to all other analysed Notch ICs, is a poor activator, and in fact acts as a repressor by blocking the ability of the Notch 1 IC to activate expression through the HES-1 and HES-5 promoters. We present a model in which Notch 3 IC interferes with Notch 1 IC-mediated activation at two levels. First, Notch 3 IC competes with Notch 1 IC for access to RBP-Jk and does not activate transcription when positioned close to a promoter. Second, Notch 3 IC appears to compete with Notch 1 IC for a common coactivator present in limiting amounts. In conclusion, this is the first example of a Notch IC that functions as a repressor in Enhancer of Split/HES upregulation, and shows that mammalian Notch receptors have acquired distinct functions during evolution.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii215-ii215
Author(s):  
Yoshihiro Otani ◽  
Ji Young Yoo ◽  
Samantha Chao ◽  
Toshihiko Shimizu ◽  
Cole Lewis ◽  
...  

Abstract NOTCH signaling is a method of cell-cell communication where membrane bound NOTCH ligands on signal-sending cells can bind to and initiate cleavage of the NOTCH receptor, releasing NICD which can initiate signal transduction in adjacent “signal-receiving” cells. We have recently shown that oHSV treatment of GBM cells induces NICD cleavage and NOTCH activation in adjacent uninfected glioma cells. RNA sequencing of GBM cells post-infection also uncovered Gene Ontology NOTCH signaling pathway to be significantly upregulated. This activation was induced by viral miRNA-H16, which represses FIH-1 expression. FIH-1 was found to be a negative regulator of Mib1, a ubiquitin ligase, which activates NOTCH ligand-mediated activation of adjacent signal-receiving cells bearing the NOTCH receptor (Otani et al Clin. Can. Res. 2020). Here we have investigated the impact of oHSV-induced NOTCH signaling on the tumor microenvironment. Treatment of brain tumors in immune competent mice with oHSV and NOTCH blocking gamma secretase inhibitor (GSI) induced an anti-tumor memory immune response. Long term survivors in mice treated with the combination also completely rejected subsequent tumor re-challenge in the other hemisphere. UMAP of flow cytometry of tumor-bearing hemispheres and functional analysis of isolated cellular fractions from treated mice showed a significant influx of MDSC cells after oHSV treatment that was rescued in mice treated with oHSV and GSI. Ongoing mechanistic studies are uncovering a significant induction of NOTCH in tumor associated macrophages that aids in recruitment of MDSC cells. Overall these studies have uncovered a significant impact of oHSV therapy on GBM tumor microenvironment and presents opportunities for combination therapies that can help improve therapeutic benefit and anti-tumor immunity.


2000 ◽  
Vol 11 (5) ◽  
pp. 1801-1814 ◽  
Author(s):  
Anastasiya D. Blagoveshchenskaya ◽  
Daniel F. Cutler

In PC12 neuroendocrine cells, synaptic-like microvesicles (SLMV) are thought to be formed by two pathways. One pathway sorts the proteins to SLMV directly from the plasma membrane (or a specialized domain thereof) in an adaptor protein complex 2-dependent, brefeldin A (BFA)-insensitive manner. Another pathway operates via an endosomal intermediate, involves adaptor protein complex 3, and is BFA sensitive. We have previously shown that when expressed in PC12 cells, HRP-P-selectin chimeras are directed to SLMV mostly via the endosomal, BFA-sensitive route. We have now found that two endosomal intermediates are involved in targeting of HRP-P-selectin chimeras to SLMV. The first intermediate is the early, transferrin-positive, epidermal growth factor-positive endosome, from which exit to SLMV is controlled by the targeting determinants YGVF and KCPL, located within the cytoplasmic domain of P-selectin. The second intermediate is the late, transferrin-negative, epidermal growth factor-positive late endosome, from where HRP-P-selectin chimeras are sorted to SLMV in a YGVF- and DPSP-dependent manner. Both sorting steps, early endosomes to SLMV and late endosomes to SLMV, are affected by BFA. In addition, analysis of double mutants with alanine substitutions of KCPL and YGVF or KCPL and DPSP indicated that chimeras pass sequentially through these intermediates en route both to lysosomes and to SLMV. We conclude that a third site of formation for SLMV, the late endosomes, exists in PC12 cells.


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.


2013 ◽  
Vol 210 (2) ◽  
pp. 301-319 ◽  
Author(s):  
Camille Lobry ◽  
Panagiotis Ntziachristos ◽  
Delphine Ndiaye-Lobry ◽  
Philmo Oh ◽  
Luisa Cimmino ◽  
...  

Notch signaling pathway activation is known to contribute to the pathogenesis of a spectrum of human malignancies, including T cell leukemia. However, recent studies have implicated the Notch pathway as a tumor suppressor in myeloproliferative neoplasms and several solid tumors. Here we report a novel tumor suppressor role for Notch signaling in acute myeloid leukemia (AML) and demonstrate that Notch pathway activation could represent a therapeutic strategy in this disease. We show that Notch signaling is silenced in human AML samples, as well as in AML-initiating cells in an animal model of the disease. In vivo activation of Notch signaling using genetic Notch gain of function models or in vitro using synthetic Notch ligand induces rapid cell cycle arrest, differentiation, and apoptosis of AML-initiating cells. Moreover, we demonstrate that Notch inactivation cooperates in vivo with loss of the myeloid tumor suppressor Tet2 to induce AML-like disease. These data demonstrate a novel tumor suppressor role for Notch signaling in AML and elucidate the potential therapeutic use of Notch receptor agonists in the treatment of this devastating leukemia.


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