Notch signaling is required for arterial-venous differentiation during embryonic vascular development

Development ◽  
2001 ◽  
Vol 128 (19) ◽  
pp. 3675-3683 ◽  
Author(s):  
Nathan D. Lawson ◽  
Nico Scheer ◽  
Van N. Pham ◽  
Cheol-Hee Kim ◽  
Ajay B. Chitnis ◽  
...  

Recent evidence indicates that acquisition of artery or vein identity during vascular development is governed, in part, by genetic mechanisms. The artery-specific expression of a number of Notch signaling genes in mouse and zebrafish suggests that this pathway may play a role in arterial-venous cell fate determination during vascular development. We show that loss of Notch signaling in zebrafish embryos leads to molecular defects in arterial-venous differentiation, including loss of artery-specific markers and ectopic expression of venous markers within the dorsal aorta. Conversely, we find that ectopic activation of Notch signaling leads to repression of venous cell fate. Finally, embryos lacking Notch function exhibit defects in blood vessel formation similar to those associated with improper arterial-venous specification. Our results suggest that Notch signaling is required for the proper development of arterial and venous blood vessels, and that a major role of Notch signaling in blood vessels is to repress venous differentiation within developing arteries.Movies available on-line

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yildiz Koca ◽  
Benjamin E. Housden ◽  
William J. Gault ◽  
Sarah J. Bray ◽  
Marek Mlodzik

AbstractIn all metazoans, a small number of evolutionarily conserved signaling pathways are reiteratively used during development to orchestrate critical patterning and morphogenetic processes. Among these, Notch (N) signaling is essential for most aspects of tissue patterning where it mediates the communication between adjacent cells to control cell fate specification. In Drosophila, Notch signaling is required for several features of eye development, including the R3/R4 cell fate choice and R7 specification. Here we show that hypomorphic alleles of Notch, belonging to the Nfacet class, reveal a novel phenotype: while photoreceptor specification in the mutant ommatidia is largely normal, defects are observed in ommatidial rotation (OR), a planar cell polarity (PCP)-mediated cell motility process. We demonstrate that during OR Notch signaling is specifically required in the R4 photoreceptor to upregulate the transcription of argos (aos), an inhibitory ligand to the epidermal growth factor receptor (EGFR), to fine-tune the activity of EGFR signaling. Consistently, the loss-of-function defects of Nfacet alleles and EGFR-signaling pathway mutants are largely indistinguishable. A Notch-regulated aos enhancer confers R4 specific expression arguing that aos is directly regulated by Notch signaling in this context via Su(H)-Mam-dependent transcription.


2002 ◽  
Vol 357 (1422) ◽  
pp. 809-813 ◽  
Author(s):  
Cathie Martin ◽  
Kiran Bhatt ◽  
Kim Baumann ◽  
Hailing Jin ◽  
Sabine Zachgo ◽  
...  

The epidermal cells of petals of many species are specialized, having a pronounced conical shape. A transcription factor, MIXTA, is required for the formation of conical cells in Antirrhinum majus ; in shoot epidermal cells of several species, expression of this gene is necessary and sufficient to promote conical cell formation. Ectopic expression has also shown MIXTA to be able to promote the formation of multicellular trichomes, indicating that conical cells and multicellular trichomes share elements of a common developmental pathway. Formation of conical cells or trichomes is also mutually exclusive with stomatal formation. In Antirrhinum , MIXTA normally only promotes conical cell formation on the inner epidermal layer of the petals. Its restricted action in cell fate determination results from its specific expression pattern. Expression of MIXTA , in turn, requires the activity of B–function genes, and biochemical evidence suggests that the products of DEFICIENS , GLOBOSA and SEPALLATA –related genes directly activate MIXTA expression late in petal development, after the completion of cell division in the petal epidermis. A MIXTA –like gene, AmMYBML1 , is also expressed in petals. AmMYBML1 expression is high early in petal development. This gene may direct the formation of trichomes in petals. In specifying the fates of different cell types in petals, regulatory genes like MIXTA may have been duplicated. Changes in the timing and spatial localization of expression then provides similar regulatory genes which specify different cell fates.


2016 ◽  
Author(s):  
Ringo Pueschel ◽  
Francesca Coraggio ◽  
Alisha Marti ◽  
Peter Meister

AbstractReprogramming of somatic cells in intact nematodes allows characterization of cell plasticity determinants, which knowledge is crucial for regenerative cell therapies. By inducing muscle or endoderm transdifferentiation by the ectopic expression of selector transcription factors, we show that cell fate is remarkably robust in fully differentiated larvae. This stability depends on the presence of the Polycomb-associated histone H3K27 methylation, but not H3K9 methylation: in the absence of this epigenetic mark, many cells can be transdifferentiated which correlates with definitive developmental arrest. A candidate RNAi screen unexpectedly uncovered that knock-down of somatic NotchLIN-12 signaling rescues this larval arrest. Similarly in a wild-type context, genetically increasing NotchLIN-12 signaling renders a fraction of the animals sensitive to induced transdifferentiation. This reveals an antagonistic role of the Polycomb repressive complex 2 stabilizing cell fate and Notch signaling enhancing cell plasticity.


2019 ◽  
Author(s):  
Yildiz Koca ◽  
Benjamin E. Housden ◽  
William J. Gault ◽  
Sarah J. Bray ◽  
Marek Mlodzik

AbstractIn all metazoans, a small number of evolutionarily conserved signaling pathways are reiteratively used during development to orchestrate critical patterning and morphogenetic processes. Among these, Notch (N) signaling is essential for most aspects of tissue patterning where it mediates the communication between adjacent cells to control cell fate specification. In Drosophila, Notch signaling is required for several features of eye development, including the R3/R4 cell fate choice and R7 specification. Here we show that hypomorphic alleles of Notch – belonging to the Nfacet class – reveal a novel phenotype: while photoreceptor specification in the mutant ommatidia is largely normal, defects are observed in ommatidial rotation (OR), a planar cell polarity (PCP)-mediated morphogenetic cell motility process. We demonstrate that during OR Notch signaling is specifically required in the R4 photoreceptor to upregulate the transcription of argos (aos), an inhibitory ligand to the EGFR, to fine-tune the activity of Egfr signaling. Consistently, the loss-of-function defects of Nfacet alleles and EGFR-signaling pathway mutants are largely indistinguishable. A Notch-regulated aos enhancer confers R4 specific expression arguing that aos is directly regulated by Notch signaling in this context via Su(H)- Mam dependent transcription.


Development ◽  
2000 ◽  
Vol 127 (5) ◽  
pp. 1115-1130 ◽  
Author(s):  
S. Zaffran ◽  
M. Frasch

The Notch signaling pathway is required, in concert with cell-type-specific transcriptional regulators and other signaling processes, for multiple cell fate decisions during mesodermal and ectodermal tissue development. In many instances, Notch signaling occurs initially in a bidirectional manner and then becomes unidirectional upon amplification of small inherent differences in signaling activity between neighboring cells. In addition to ligands and extracellular modulators of the Notch receptor, several intracellular proteins have been identified that can positively or negatively influence the activity of the Notch pathway during these dynamic processes. Here, we describe a new gene, Barbu, whose product can antagonize Notch signaling activity during Drosophila development. Barbu encodes a small and largely cytoplasmic protein with sequence similarity to the proteins encoded by the transcription units m4 and m(alpha) of the E(spl) complex. Ectopic expression studies with Barbu provide evidence that Barbu can antagonize Notch during lateral inhibition processes in the embryonic mesoderm, sensory organ specification in imaginal discs and cell type specification in developing ommatidia. Barbu loss-of-function mutations cause lethality and disrupt the establishment of planar polarity and photoreceptor specification in eye imaginal discs, which may also be a consequence of altered Notch signaling activities. Furthermore, in the embryonic neuroectoderm, Barbu expression is inducible by activated Notch. Taken together, we propose that Barbu functions in a negative feed-back loop, which may be important for the accurate adjustment of Notch signaling activity and the extinction of Notch activity between successive rounds of signaling events.


Development ◽  
2002 ◽  
Vol 129 (13) ◽  
pp. 3045-3054 ◽  
Author(s):  
Thomas Theil ◽  
Songül Aydin ◽  
Silke Koch ◽  
Lars Grotewold ◽  
Ulrich Rüther

Pattern formation of the dorsal telencephalon is governed by a regionalisation process that leads to the formation of distinct domains, including the future hippocampus and neocortex. Recent studies have implicated signalling proteins of the Wnt and Bmp gene families as well as several transcription factors, including Gli3 and the Emx homeobox genes, in the molecular control of this process. The regulatory relationships between these genes, however, remain largely unknown. We have used transgenic analysis to investigate the upstream mechanisms for regulation of Emx2 in the dorsal telencephalon. We have identified an enhancer from the mouse Emx2 gene that drives specific expression of a lacZ reporter gene in the dorsal telencephalon. This element contains binding sites for Tcf and Smad proteins, transcriptional mediators of the Wnt and Bmp signalling pathway, respectively. Mutations of these binding sites abolish telencephalic enhancer activity, while ectopic expression of these signalling pathways leads to ectopic activation of the enhancer. These results establish Emx2 as a direct transcriptional target of Wnt and Bmp signalling and provide insights into a genetic hierarchy involving Gli3, Emx2 and Bmp and Wnt genes in the control of dorsal telencephalic development.


eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Pengpeng Li ◽  
Kevin M Collins ◽  
Michael R Koelle ◽  
Kang Shen

The diverse cell types and the precise synaptic connectivity between them are the cardinal features of the nervous system. Little is known about how cell fate diversification is linked to synaptic target choices. Here we investigate how presynaptic neurons select one type of muscles, vm2, as a synaptic target and form synapses on its dendritic spine-like muscle arms. We found that the Notch-Delta pathway was required to distinguish target from non-target muscles. APX-1/Delta acts in surrounding cells including the non-target vm1 to activate LIN-12/Notch in the target vm2. LIN-12 functions cell-autonomously to up-regulate the expression of UNC-40/DCC and MADD-2 in vm2, which in turn function together to promote muscle arm formation and guidance. Ectopic expression of UNC-40/DCC in non-target vm1 muscle is sufficient to induce muscle arm extension from these cells. Therefore, the LIN-12/Notch signaling specifies target selection by selectively up-regulating guidance molecules and forming muscle arms in target cells.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 521
Author(s):  
Catia Giovannini ◽  
Francesca Fornari ◽  
Fabio Piscaglia ◽  
Laura Gramantieri

The Notch family includes evolutionary conserved genes that encode for single-pass transmembrane receptors involved in stem cell maintenance, development and cell fate determination of many cell lineages. Upon activation by different ligands, and depending on the cell type, Notch signaling plays pleomorphic roles in hepatocellular carcinoma (HCC) affecting neoplastic growth, invasion capability and stem like properties. A specific knowledge of the deregulated expression of each Notch receptor and ligand, coupled with resultant phenotypic changes, is still lacking in HCC. Therefore, while interfering with Notch signaling might represent a promising therapeutic approach, the complexity of Notch/ligands interactions and the variable consequences of their modulations raises concerns when performed in undefined molecular background. The gamma-secretase inhibitors (GSIs), representing the most utilized approach for Notch inhibition in clinical trials, are characterized by important adverse effects due to the non-specific nature of GSIs themselves and to the lack of molecular criteria guiding patient selection. In this review, we briefly summarize the mechanisms involved in Notch pathway activation in HCC supporting the development of alternatives to the γ-secretase pan-inhibitor for HCC therapy.


Author(s):  
Giovanna Carrà ◽  
Giuseppe Ermondi ◽  
Chiara Riganti ◽  
Luisella Righi ◽  
Giulia Caron ◽  
...  

Abstract Background Oxidative stress is a hallmark of many cancers. The increment in reactive oxygen species (ROS), resulting from an increased mitochondrial respiration, is the major cause of oxidative stress. Cell fate is known to be intricately linked to the amount of ROS produced. The direct generation of ROS is also one of the mechanisms exploited by common anticancer therapies, such as chemotherapy. Methods We assessed the role of NFKBIA with various approaches, including in silico analyses, RNA-silencing and xenotransplantation. Western blot analyses, immunohistochemistry and RT-qPCR were used to detect the expression of specific proteins and genes. Immunoprecipitation and pull-down experiments were used to evaluate protein-protein interactions. Results Here, by using an in silico approach, following the identification of NFKBIA (the gene encoding IκBα) amplification in various cancers, we described an inverse correlation between IκBα, oxidative metabolism, and ROS production in lung cancer. Furthermore, we showed that novel IκBα targeting compounds combined with cisplatin treatment promote an increase in ROS beyond the tolerated threshold, thus causing death by oxytosis. Conclusions NFKBIA amplification and IκBα overexpression identify a unique cancer subtype associated with specific expression profile and metabolic signatures. Through p65-NFKB regulation, IκBα overexpression favors metabolic rewiring of cancer cells and distinct susceptibility to cisplatin. Lastly, we have developed a novel approach to disrupt IκBα/p65 interaction, restoring p65-mediated apoptotic responses to cisplatin due to mitochondria deregulation and ROS-production.


Blood ◽  
2011 ◽  
Vol 118 (4) ◽  
pp. 1154-1162 ◽  
Author(s):  
Wei Zheng ◽  
Tuomas Tammela ◽  
Masahiro Yamamoto ◽  
Andrey Anisimov ◽  
Tanja Holopainen ◽  
...  

Abstract Notch signaling plays a central role in cell-fate determination, and its role in lateral inhibition in angiogenic sprouting is well established. However, the role of Notch signaling in lymphangiogenesis, the growth of lymphatic vessels, is poorly understood. Here we demonstrate Notch pathway activity in lymphatic endothelial cells (LECs), as well as induction of delta-like ligand 4 (Dll4) and Notch target genes on stimulation with VEGF or VEGF-C. Suppression of Notch signaling by a soluble form of Dll4 (Dll4-Fc) synergized with VEGF in inducing LEC sprouting in 3-dimensional (3D) fibrin gel assays. Expression of Dll4-Fc in adult mouse ears promoted lymphangiogenesis, which was augmented by coexpressing VEGF. Lymphangiogenesis triggered by Notch inhibition was suppressed by a monoclonal VEGFR-2 Ab as well as soluble VEGF and VEGF-C/VEGF-D ligand traps. LECs transduced with Dll4 preferentially adopted the tip cell position over nontransduced cells in 3D sprouting assays, suggesting an analogous role for Dll4/Notch in lymphatic and blood vessel sprouting. These results indicate that the Notch pathway controls lymphatic endothelial quiescence, and explain why LECs are poorly responsive to VEGF compared with VEGF-C. Understanding the role of the Notch pathway in lymphangiogenesis provides further insight for the therapeutic manipulation of the lymphatic vessels.


Sign in / Sign up

Export Citation Format

Share Document