scholarly journals Notch Signaling May Negatively Regulate Neonatal Rat Cardiac Fibroblast-Myofibroblast Transformation

2011 ◽  
pp. 739-748 ◽  
Author(s):  
Y.-H. FAN ◽  
H. DONG ◽  
Q. PAN ◽  
Y.-J. CAO ◽  
H. LI ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Myocardial Fibrosis ◽  
Collagen Synthesis ◽  
Butyl Ester ◽  
Cardiac Fibroblast ◽  
Notch Receptor ◽  
Neonatal Rat ◽  
Dependent Manner ◽  
Notch Receptors ◽  
Tgf Β1

Cardiac fibroblast-myofibroblast transformation (CMT) is a critical event in the initiation of myocardial fibrosis. Notch signaling has been shown to regulate myofibroblast transformation from other kinds of cells. However, whether Notch signaling is also involved in CMT remains unclear. In the present study, expressions of Notch receptors in cardiac fibroblasts (CFs) were examined, effects of Notch signaling inhibitor N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT) and transforming growth factor-β1 (TGF-β1) on CMT were determined by increasing alpha-smooth muscle actin (α-SMA) expression and collagen synthesis, and Notch signaling was examined by analyzing expressions of Notch receptors. The results showed that: (1) Notch receptor 1, 2, 3 and 4 were all expressed in CFs; (2) DAPT promoted CMT in a time-dependent manner; (3) During the period of CMT induced by TGF-β1, expressions of Notch receptor 1, 3 and 4 in CFs were down-regulated, whereas there was no change for Notch receptor 2. Moreover, the downtrends of Notch 1, 3 and 4 were corresponding to the trend growth of α-SMA expression and collagen synthesis. These results suggested that inhibiting of Notch signaling might promote CMT. The down-regulations of Notch receptor 1, 3 and 4 induced by TGF-β1 may facilitate CMT. In conclusion, inhibition of Notch signaling might be a novel mechanism of CMT in myocardial fibrosis.

scholarly journals NOTCH3 signaling is essential for NF-κB activation in TLR-activated macrophages

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Susana López-López ◽  
Eva María Monsalve ◽  
María José Romero de Ávila ◽  
Julia González-Gómez ◽  
Natalia Hernández de León ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Macrophage Activation ◽  
Notch Signaling Pathway ◽  
P38 Map Kinase ◽  
Notch Receptor ◽  
Dependent Manner ◽  
Activated Macrophages ◽  
Notch Receptors ◽  
Inflammatory Processes ◽  
Tlr4 Activation

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.

scholarly journals Current Views on the Roles of O-Glycosylation in Controlling Notch-Ligand Interactions

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 309
Author(s):  
Wataru Saiki ◽  
Chenyu Ma ◽  
Tetsuya Okajima ◽  
Hideyuki Takeuchi
Keyword(s):  
Notch Signaling ◽  
100Th Anniversary ◽  
Notch Receptor ◽  
Notch Receptors ◽  
Evolutionarily Conserved ◽  
Future Challenges ◽  
Ligand Interactions ◽  
Epidermal Growth ◽  
Notch Activation ◽  
Human Specific

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.

scholarly journals POS0042 NOTCH 1 INHIBITION INCREASES OSTEOCLAST PROGENITOR ACTIVITY IN THE MOUSE MODEL OF RHEUMATOID ARTHRITIS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 226.3-226
Author(s):  
M. Filipović ◽  
A. Šućur ◽  
D. Flegar ◽  
Z. Jajić ◽  
M. Ikić Matijašević ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Notch Signaling ◽  
Neutralizing Antibodies ◽  
Osteoclast Differentiation ◽  
Notch Receptor ◽  
Notch 1 ◽  
Collagen Induced Arthritis ◽  
Notch Receptors

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.

scholarly journals The retromer complex safeguards against neural progenitor-derived tumorigenesis by regulating Notch receptor trafficking

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Bo Li ◽  
Chouin Wong ◽  
Shihong Max Gao ◽  
Rulan Zhang ◽  
Rongbo Sun ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Molecular Mechanisms ◽  
Neural Progenitor ◽  
Tumor Formation ◽  
Neural Progenitors ◽  
Notch Receptor ◽  
Dependent Manner ◽  
Cell Fate Decisions ◽  
Retromer Complex ◽  
Signaling Activation

The correct establishment and maintenance of unidirectional Notch signaling are critical for the homeostasis of various stem cell lineages. However, the molecular mechanisms that prevent cell-autonomous ectopic Notch signaling activation and deleterious cell fate decisions remain unclear. Here we show that the retromer complex directly and specifically regulates Notch receptor retrograde trafficking in Drosophila neuroblast lineages to ensure the unidirectional Notch signaling from neural progenitors to neuroblasts. Notch polyubiquitination mediated by E3 ubiquitin ligase Itch/Su(dx) is inherently inefficient within neural progenitors, relying on retromer-mediated trafficking to avoid aberrant endosomal accumulation of Notch and cell-autonomous signaling activation. Upon retromer dysfunction, hypo-ubiquitinated Notch accumulates in Rab7+ enlarged endosomes, where it is ectopically processed and activated in a ligand-dependent manner, causing progenitor-originated tumorigenesis. Our results therefore unveil a safeguard mechanism whereby retromer retrieves potentially harmful Notch receptors in a timely manner to prevent aberrant Notch activation-induced neural progenitor dedifferentiation and brain tumor formation.

scholarly journals Binding of Delta1, Jagged1, and Jagged2 to Notch2 Rapidly Induces Cleavage, Nuclear Translocation, and Hyperphosphorylation of Notch2

2000 ◽  
Vol 20 (18) ◽  
pp. 6913-6922 ◽  
Author(s):  
Kiyoshi Shimizu ◽  
Shigeru Chiba ◽  
Noriko Hosoya ◽  
Keiki Kumano ◽  
Toshiki Saito ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Notch Signaling ◽  
Time Course ◽  
Nuclear Translocation ◽  
Reporter Genes ◽  
Time Dependent ◽  
Dependent Manner ◽  
Notch Receptors ◽  
Notch Protein ◽  
Membrane Spanning

ABSTRACT Delta1, Jagged1, and Jagged2, commonly designated Delta/Serrate/LAG-2 (DSL) proteins, are known to be ligands for Notch1. However, it has been less understood whether they are ligands for Notch receptors other than Notch1. Meanwhile, ligand-induced cleavage and nuclear translocation of the Notch protein are considered to be fundamental for Notch signaling, yet direct observation of the behavior of the Notch molecule after ligand binding, including cleavage and nuclear translocation, has been lacking. In this report, we investigated these issues for Notch2. All of the three DSL proteins bound to endogenous Notch2 on the surface of BaF3 cells, although characteristics of Jagged2 for binding to Notch2 apparently differed from that of Delta1 and Jagged1. After binding, the three DSL proteins induced cleavage of the membrane-spanning subunit of Notch2 (Notch2TM), which occurred within 15 min. In a simultaneous time course, the cleaved fragment of Notch2TMwas translocated into the nucleus. Interestingly, the cleaved Notch2 fragment was hyperphosphorylated also in a time-dependent manner. Finally, binding of DSL proteins to Notch2 also activated the transcription of reporter genes driven by the RBP-Jκ-responsive promoter. Together, these data indicate that all of these DSL proteins function as ligands for Notch2. Moreover, the findings of rapid cleavage, nuclear translocation, and phosphorylation of Notch2 after ligand binding facilitate the understanding of the Notch signaling.

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
Keyword(s):  
Notch Signaling ◽  
Asymmetric Cell Division ◽  
Adaptor Protein ◽  
Notch Signaling Pathway ◽  
Notch Receptor ◽  
Recycling Endosome ◽  
Notch Receptors ◽  
Late Endosomes ◽  
Early Endosomes ◽  
Sensory Organ Precursor

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.

scholarly journals Enhancement of Notch receptor maturation and signaling sensitivity by Cripto-1

2009 ◽  
Vol 187 (3) ◽  
pp. 343-353 ◽  
Author(s):  
Kazuhide Watanabe ◽  
Tadahiro Nagaoka ◽  
Joseph M. Lee ◽  
Caterina Bianco ◽  
Monica Gonzales ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Notch Receptor ◽  
Carcinoma Cells ◽  
Vertebrate Development ◽  
Notch Receptors ◽  
Epidermal Growth ◽  
Signaling Activation ◽  
Lipid Raft Microdomains ◽  
Golgi Network

Nodal and Notch signaling pathways play essential roles in vertebrate development. Through a yeast two-hybrid screening, we identified Notch3 as a candidate binding partner of the Nodal coreceptor Cripto-1. Coimmunoprecipitation analysis confirmed the binding of Cripto-1 with all four mammalian Notch receptors. Deletion analyses revealed that the binding of Cripto-1 and Notch1 is mediated by the Cripto-1/FRL-1/Cryptic domain of Cripto-1 and the C-terminal region of epidermal growth factor–like repeats of Notch1. Binding of Cripto-1 to Notch1 occurred mainly in the endoplasmic reticulum–Golgi network. Cripto-1 expression resulted in the recruitment of Notch1 protein into lipid raft microdomains and enhancement of the furin-like protein convertase-mediated proteolytic maturation of Notch1 (S1 cleavage). Enhanced S1 cleavage resulted in the sensitization to ligand-induced activation of Notch signaling. In addition, knockdown of Cripto-1 expression in human and mouse embryonal carcinoma cells desensitized the ligand-induced Notch signaling activation. These results suggest a novel role of Cripto-1 in facilitating the posttranslational maturation of Notch receptors.

scholarly journals Protein O-fucosyltransferase 1 (Pofut1) regulates lymphoid and myeloid homeostasis through modulation of Notch receptor ligand interactions

Blood ◽  
2011 ◽  
Vol 117 (21) ◽  
pp. 5652-5662 ◽  
Author(s):  
David Yao ◽  
Yuanshuai Huang ◽  
Xiaoran Huang ◽  
Weihuan Wang ◽  
Quanjian Yan ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Notch Receptor ◽  
Cell Surface Expression ◽  
Developmental Defects ◽  
Marginal Zone B Cells ◽  
Notch Ligand ◽  
Notch Receptors ◽  
Ligand Interactions ◽  
Notch Ligands ◽  
T Lymphopoiesis

Abstract Notch signaling is essential for lymphocyte development and is also implicated in myelopoiesis. Notch receptors are modified by O-fucosylation catalyzed by protein O-fucosyltransferase 1 (Pofut1). Fringe enzymes add N-acetylglucosamine to O-fucose and modify Notch signaling by altering the sensitivity of Notch receptors to Notch ligands. To address physiologic functions in hematopoiesis of Notch modified by O-fucose glycans, we examined mice with inducible inactivation of Pofut1 using Mx-Cre. These mice exhibited a reduction in T lymphopoiesis and in the production of marginal-zone B cells, in addition to myeloid hyperplasia. Restoration of Notch1 signaling rescued T lymphopoiesis and the marrow myeloid hyperplasia. After marrow transfer, both cell-autonomous and environmental cues were found to contribute to lymphoid developmental defects and myeloid hyperplasia in Pofut1-deleted mice. Although Pofut1 deficiency slightly decreased cell surface expression of Notch1 and Notch2, it completely abrogated the binding of Notch receptors with Delta-like Notch ligands and suppressed downstream Notch target activation, indicating that O-fucose glycans are critical for efficient Notch-ligand binding that transduce Notch signals. The combined data support a key role for the O-fucose glycans generated by Pofut1 in Notch regulation of hematopoietic homeostasis through modulation of Notch-ligand interactions.

scholarly journals FZD2 Promotes TGF-β-Induced Epithelial-to-Mesenchymal Transition in Breast Cancer via Activating Notch Signaling Pathway

2020 ◽  
Author(s):  
Dilihumaer Tuluhong ◽  
Tao Chen ◽  
Jingjie Wang ◽  
Huijuan Zeng ◽  
Hanjun Li ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Growth ◽  
Notch Signaling ◽  
Signaling Pathway ◽  
Notch Signaling Pathway ◽  
Cell Counting ◽  
Dependent Manner ◽  
Mesenchymal Transition ◽  
Tgf Β1

Abstract Background Breast cancer (BC) is one of the commonest female cancers, which is characterized with high incidence. Although treatments have been improved, the prognosis of BC patients in advanced stages remains unsatisfactory. Thus, exploration of the molecular mechanisms underneath BC progression is necessary to find novel therapeutic methods. Frizzled class receptor (FZD2) belongs to Frizzled family, which has been proven to promote cell growth and invasion in various human cancers. The purpose of our study was to detect the functions of FZD2 and explore its mechanism in BC. Methods The level of FZD2 was measured in BC tissues by quantitative realtime polymerase chain reaction (qRT-PCR), western blot, immunohistochemistry (IHC) respectively. Cell Counting Kit-8 (CCK-8), standard colony formation, transwell aasays, wound healing and flow cytometry experiments were adopted separately to test cell viability, invasion, migration, apoptosis and cell cycle distribution. Epithelial-mesenchymal transition (EMT) biomarker were determined by using Immunofluorescence assay. Xenograft tumorigenicity assay was performed to assess the effect of FZD2 on tumor growth in vivo. Results We determined that FZD2 mRNA and protein expression was abundant in BC tissues. Moreover, high level of FZD2 had significant correlation with poor prognosis. In vitro functional assays revealed that silencing of FZD2 had suppressive effects on BC cell growth, migration and invasion. Animal study further demonstrated that FZD2 silencing inhibited BC cell growth in vivo. In addition, FZD2 induced EMT in BC cells in a transforming growth factor (TGF)-β1-dependent manner. Mechanistically, knockdown of FZD2 led to the inactivation of Notch signaling pathway. Conclusion Based on all these data, we concluded that FZD2 facilitates BC progression and promotes TGF-β1-inudced EMT process through activating Notch signaling pathway.

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