scholarly journals Unique functions for Notch4 in murine embryonic lymphangiogenesis

Angiogenesis ◽  
2021 ◽  
Author(s):  
Ajit Muley ◽  
Minji Kim Uh ◽  
Glicella Salazar-De Simone ◽  
Bhairavi Swaminathan ◽  
Jennifer M. James ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Dominant Role ◽  
Dominant Negative ◽  
Cell Fate Decisions ◽  
Dominant Negative Form ◽  
Evolutionarily Conserved ◽  
Lymphatic Development ◽  
Lymphatic Density ◽  
Negative Form

AbstractIn mice, embryonic dermal lymphatic development is well understood and used to study gene functions in lymphangiogenesis. Notch signaling is an evolutionarily conserved pathway that modulates cell fate decisions, which has been shown to both inhibit and promote dermal lymphangiogenesis. Here, we demonstrate distinct roles for Notch4 signaling versus canonical Notch signaling in embryonic dermal lymphangiogenesis. Actively growing embryonic dermal lymphatics expressed NOTCH1, NOTCH4, and DLL4 which correlated with Notch activity. In lymphatic endothelial cells (LECs), DLL4 activation of Notch induced a subset of Notch effectors and lymphatic genes, which were distinctly regulated by Notch1 and Notch4 activation. Treatment of LECs with VEGF-A or VEGF-C upregulated Dll4 transcripts and differentially and temporally regulated the expression of Notch1 and Hes/Hey genes. Mice nullizygous for Notch4 had an increase in the closure of the lymphangiogenic fronts which correlated with reduced vessel caliber in the maturing lymphatic plexus at E14.5 and reduced branching at E16.5. Activation of Notch4 suppressed LEC migration in a wounding assay significantly more than Notch1, suggesting a dominant role for Notch4 in regulating LEC migration. Unlike Notch4 nulls, inhibition of canonical Notch signaling by expressing a dominant negative form of MAML1 (DNMAML) in Prox1+ LECs led to increased lymphatic density consistent with an increase in LEC proliferation, described for the loss of LEC Notch1. Moreover, loss of Notch4 did not affect LEC canonical Notch signaling. Thus, we propose that Notch4 signaling and canonical Notch signaling have distinct functions in the coordination of embryonic dermal lymphangiogenesis.

Unique functions for Notch4 in murine embryonic lymphangiogenesis

2021 ◽  
Author(s):  
Ajit Muley ◽  
Minji Kim Uh ◽  
Jennifer M. James ◽  
Aino Murtomaki ◽  
Joseph D. McCarron ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Notch Signaling ◽  
Cell Fate ◽  
Dominant Role ◽  
Lymphatic Endothelial Cell ◽  
Dominant Negative ◽  
Endothelial Cell Migration ◽  
Endothelial Cell Proliferation ◽  
Lymphatic Endothelium ◽  
Cell Fate Decisions

AbstractIn mice, embryonic dermal lymphatic development is a well-understood system used to study the role of genes in physiological lymphangiogenesis. The Notch signaling is an evolutionary conserved pathway that modulates cell fate decisions and shown to both inhibit and promote dermal lymphangiogenesis. Here, we demonstrate distinct roles for Notch4 signaling versus canonical Notch signaling in embryonic dermal lymphangiogenesis. At E14.5, actively growing dermal lymphatics expressed NOTCH1, NOTCH4 and DLL4, with DLL4 expression strongest and Notch active in the lymphangiogenic sprouts. Treatment of cultured LECs with VEGF-A or VEGF-C upregulated Dll4 transcripts, but differentially regulated Notch1 and Notch4 expression, and the Notch effectors of the Hes/Hey families, suggesting that VEGF-A and VEGF-C distinctly modulate Dll4/Notch signaling in the lymphatic endothelium. Mice nullizygous for Notch4 had an increase in the closure of the lymphangiogenic fronts towards the midline which correlated with reduced vessel caliber in the maturing lymphatic plexus. Activation of Notch4 suppressed lymphatic endothelial cell migration in a wounding assay significantly more then Notch1 activation, suggesting a dominant role for Notch4 in LEC migration. Unlike Notch4 nulls, inhibition of canonical Notch signaling by ectopically expressing a dominant negative form of MAML1 (DNMAML) in Prox1+ lymphatic endothelium suppressed lymphatic endothelial cell proliferation consistent with what has been described for the loss of lymphatic endothelial Notch1. Moreover, loss of Notch4 did not disrupt lymphatic endothelial canonical Notch signaling. Thus, we propose that Notch4 signaling and canonical Notch signaling have distinct functions in the coordination of embryonic dermal lymphangiogenesis.

Serrate and Notch specify cell fates in the heart field by suppressing cardiomyogenesis

Development ◽  
2000 ◽  
Vol 127 (17) ◽  
pp. 3865-3876
Author(s):  
M.S. Rones ◽  
K.A. McLaughlin ◽  
M. Raffin ◽  
M. Mercola
Keyword(s):  
Gene Expression ◽  
Notch Signaling ◽  
Cell Fate ◽  
Notch Pathway ◽  
Cell Types ◽  
Myocardial Cell ◽  
Dominant Negative ◽  
Cell Fates ◽  
Cell Fate Decisions ◽  
Heart Field

Notch signaling mediates numerous developmental cell fate decisions in organisms ranging from flies to humans, resulting in the generation of multiple cell types from equipotential precursors. In this paper, we present evidence that activation of Notch by its ligand Serrate apportions myogenic and non-myogenic cell fates within the early Xenopus heart field. The crescent-shaped field of heart mesoderm is specified initially as cardiomyogenic. While the ventral region of the field forms the myocardial tube, the dorsolateral portions lose myogenic potency and form the dorsal mesocardium and pericardial roof (Raffin, M., Leong, L. M., Rones, M. S., Sparrow, D., Mohun, T. and Mercola, M. (2000) Dev. Biol., 218, 326–340). The local interactions that establish or maintain the distinct myocardial and non-myocardial domains have never been described. Here we show that Xenopus Notch1 (Xotch) and Serrate1 are expressed in overlapping patterns in the early heart field. Conditional activation or inhibition of the Notch pathway with inducible dominant negative or active forms of the RBP-J/Suppressor of Hairless [Su(H)] transcription factor indicated that activation of Notch feeds back on Serrate1 gene expression to localize transcripts more dorsolaterally than those of Notch1, with overlap in the region of the developing mesocardium. Moreover, Notch pathway activation decreased myocardial gene expression and increased expression of a marker of the mesocardium and pericardial roof, whereas inhibition of Notch signaling had the opposite effect. Activation or inhibition of Notch also regulated contribution of individual cells to the myocardium. Importantly, expression of Nkx2. 5 and Gata4 remained largely unaffected, indicating that Notch signaling functions downstream of heart field specification. We conclude that Notch signaling through Su(H) suppresses cardiomyogenesis and that this activity is essential for the correct specification of myocardial and non-myocardial cell fates.

Notch1 inhibits differentiation of hematopoietic cells by sustaining GATA-2 expression

Blood ◽  
2001 ◽  
Vol 98 (12) ◽  
pp. 3283-3289 ◽  
Author(s):  
Keiki Kumano ◽  
Shigeru Chiba ◽  
Kiyoshi Shimizu ◽  
Tetsuya Yamagata ◽  
Noriko Hosoya ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Notch Signaling ◽  
Cell Fate ◽  
Hematopoietic Cells ◽  
Erythroid Differentiation ◽  
Inhibitory Effect ◽  
Dominant Negative ◽  
Granulocytic Differentiation ◽  
Cell Fate Decisions ◽  
Delayed Differentiation

Abstract Notch signaling is involved in cell fate decisions in many systems including hematopoiesis. It has been shown that expression of an activated form of Notch1 (aNotch1) in 32D mouse myeloid progenitor cells inhibits the granulocytic differentiation induced by granulocyte colony-stimulating factor (G-CSF). Results of the current study show that aNotch1, when expressed in F5-5 mouse erythroleukemia cells, also inhibits erythroid differentiation. Comparison of the expression levels of several transcription factors after stimulation for myeloid and erythroid differentiation, in the presence or absence of aNotch1, revealed that aNotch1 did not change its regulation pattern with any of the transcription factors examined, except for GATA-2, despite its inhibitory effect on differentiation. GATA-2 was down-regulated when the parental 32D and F5-5 were induced to differentiate into granulocytic and erythroid lineages, respectively. In these induction procedures, however, the level of GATA-2 expression was sustained when aNotch1 was expressed. To ascertain whether maintenance of GATA-2 is required for the Notch-induced inhibition of differentiation, the dominant-negative form of GATA-3 (DN-GATA), which acted also against GATA-2, or transcription factor PU.1, which was recently shown to be the repressor of GATA-2, was introduced into aNotch1-expressing 32D (32D/aNotch1) cells that do not express GATA family proteins other than GATA2. Both DN-GATA and PU.1 reversed the phenotype of 32D/aNotch1 inducing its differentiation when G-CSF was added. Furthermore, enforced expression of HES-1, which is involved in Notch signaling, delayed differentiation of 32D, and again this phenotype was neutralized by DN-GATA. These results indicate that GATA-2 activity is necessary for the Notch signaling in hematopoietic cells.

scholarly journals An EP overexpression screen for genetic modifiers of Notch pathway function in Drosophila melanogaster

2004 ◽  
Vol 83 (2) ◽  
pp. 71-82 ◽  
Author(s):  
LAUREN E. HALL ◽  
SHAUNA J. ALEXANDER ◽  
MICHAEL CHANG ◽  
NATHANIEL S. WOODLING ◽  
BARRY YEDVOBNICK
Keyword(s):  
Notch Signaling ◽  
Notch Pathway ◽  
Dominant Negative ◽  
Genetic Modifiers ◽  
Loss Of Function ◽  
Partial Loss ◽  
Dominant Negative Form ◽  
Nuclear Component ◽  
Pathway Function ◽  
Negative Form

The Notch pathway comprises a signal transduction cascade required for the proper formation of multiple tissues during metazoan development. Originally described in Drosophila for its role in nervous system formation, the pathway has attracted much wider interest owing to its fundamental roles in a range of developmental and disease-related processes. Despite extensive analysis, Notch signaling is not completely understood and it appears that additional components of the pathway remain to be identified and characterized. Here, we describe a novel genetic strategy to screen for additional Notch pathway genes. The strategy combines partial loss of function for pathway activity with Enhancer-promoter (EP)-induced overexpression of random loci across the dorsoventral wing margin. Mastermind (Mam) is a nuclear component of the Notch signaling cascade. Using a GAL4-UAS-driven dominant-negative form of Mam, we created a genotype that exhibits a completely penetrant dominant wing-nicking phenotype. This phenotype was assayed for enhancement or suppression after outcrossing to several thousand EP lines. The screen identified known components or modifiers of Notch pathway function, as well as several potential new components. Our results suggest that a genetic screen that combines partial loss of function with random gene overexpression might be a useful strategy in the analysis of developmental pathways.

The evolutionarily conserved Dim1 protein defines a novel branch of the thioredoxin fold superfamily

1999 ◽  
Vol 1 (3) ◽  
pp. 109-118 ◽  
Author(s):  
YU-ZHU ZHANG ◽  
KATHLEEN L. GOULD ◽  
ROLAND L. DUNBRACK ◽  
HONG CHENG ◽  
HEINRICH RODER ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Mutational Analysis ◽  
Mrna Splicing ◽  
Dominant Negative ◽  
Cycle Arrest ◽  
Dominant Negative Form ◽  
Sequence Homologies ◽  
Evolutionarily Conserved ◽  
Carboxy Terminal ◽  
Negative Form

Zhang, Yu-Zhu, Kathleen L. Gould, Roland L. Dunbrack, Jr., Hong Cheng, Heinrich Roder, and Erica A. Golemis. The evolutionarily conserved Dim1 protein defines a novel branch of the thioredoxin fold superfamily. Physiol. Genomics 1: 109–118, 1999.—Dim1 is a small evolutionarily conserved protein essential for G2/M transition that has recently been implicated as a component of the mRNA splicing machinery. To date, the mechanism of Dim1 function remains poorly defined, in part because of the absence of informative sequence homologies between Dim1 and other functionally defined proteins or protein domains. We have used a combination of molecular modeling and NMR structural analysis to demonstrate that ∼125 of the 142 amino acids of human Dim1 (hDim1) define a novel branch of the thioredoxin fold superfamily. Mutational analysis of Dim1 based on the predicted fold indicates that alterations in the region corresponding to the thioredoxin active site do not affect Dim1 activity. However, removal of a very short carboxy-terminal extension generates a dominant negative form of the protein [hDim1-(1–128)] that when overproduced induces cell cycle arrest in G2, via a mechanism likely to involve alteration of Dim1 association with partner molecules. In sum, this study identifies the Dim1 proteins as a novel sixth branch of the thioredoxin superfamily involved in cell cycle.

scholarly journals Metabolic Control of m6A RNA Modification

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 80
Author(s):  
Joohwan Kim ◽  
Gina Lee
Keyword(s):  
Cell Fate ◽  
Metabolic Pathways ◽  
Epigenetic Modification ◽  
Genetic Material ◽  
Rna Modification ◽  
Cell Fate Decisions ◽  
Disease States ◽  
Evolutionarily Conserved ◽  
Regulate Cell Growth ◽  
Epigenetic Processes

Nutrients and metabolic pathways regulate cell growth and cell fate decisions via epigenetic modification of DNA and histones. Another key genetic material, RNA, also contains diverse chemical modifications. Among these, N6-methyladenosine (m6A) is the most prevalent and evolutionarily conserved RNA modification. It functions in various aspects of developmental and disease states, by controlling RNA metabolism, such as stability and translation. Similar to other epigenetic processes, m6A modification is regulated by specific enzymes, including writers (methyltransferases), erasers (demethylases), and readers (m6A-binding proteins). As this is a reversible enzymatic process, metabolites can directly influence the flux of this reaction by serving as substrates and/or allosteric regulators. In this review, we will discuss recent understanding of the regulation of m6A RNA modification by metabolites, nutrients, and cellular metabolic pathways.

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