scholarly journals Fibrous Caps in Atherosclerosis Form by Notch-Dependent Mechanisms Common to Arterial Media Development

2021 ◽  
Author(s):  
Carlos J. Martos-Rodríguez ◽  
Julián Albarrán-Juárez ◽  
Daniel Morales-Cano ◽  
Ainoa Caballero ◽  
Donal MacGrogan ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Notch Pathway ◽  
Lineage Tracing ◽  
Conditional Knockout ◽  
Fibrous Cap ◽  
Notch Intracellular Domain ◽  
Sequential Loss ◽  
Conditional Expression ◽  
Subendothelial Space ◽  
Atherosclerosis Development

Objective: Atheromatous fibrous caps are produced by smooth muscle cells (SMCs) that are recruited to the subendothelial space. We tested whether the recruitment mechanisms are the same as in embryonic artery development, which relies prominently on Notch signaling to form the subendothelial medial SMC layers. Approach and Results: Notch elements were expressed in regions of fibrous cap in human and mouse plaques. To assess the causal role of Notch signaling in cap formation, we studied atherosclerosis in mice where the Notch pathway was inactivated in SMCs by conditional knockout of the essential effector transcription factor RBPJ. The recruitment of cap SMCs was significantly reduced without major effects on plaque size. Lineage tracing revealed the accumulation of SMC-derived plaque cells in the cap region was unaltered but that Notch-defective cells failed to re-acquire the SMC phenotype in the cap. Conversely, to analyze whether the loss of Notch signaling is required for SMC-derived cells to accumulate in atherogenesis, we studied atherosclerosis in mice with constitutive activation of Notch signaling in SMCs achieved by conditional expression of the Notch intracellular domain. Forced Notch signaling inhibited the ability of medial SMCs to contribute to plaque cells, including both cap SMCs and osteochondrogenic cells, and significantly reduced atherosclerosis development. Conclusions: Sequential loss and gain of Notch signaling is needed to build the cap SMC population. The shared mechanisms with embryonic arterial media assembly suggest that the cap forms as a neo-media that restores the connection between endothelium and subendothelial SMCs, transiently disrupted in early atherogenesis.

scholarly journals Fibrous caps in atherosclerosis form by Notch-dependent mechanisms common to arterial media development

2020 ◽  
Author(s):  
Carlos J. Martos ◽  
Julián Albarrán-Juárez ◽  
Daniel Morales-Cano ◽  
Ainoa Caballero ◽  
Donal MacGrogan ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Notch Pathway ◽  
Notch Signaling Pathway ◽  
Lineage Tracing ◽  
Conditional Knockout ◽  
Media Development ◽  
Fibrous Cap ◽  
Conditional Expression ◽  
Subendothelial Space ◽  
Atherosclerosis Development

AbstractRationaleThe rupture of the fibrous cap in atherosclerotic lesions is the underlying cause of most thrombi leading to heart attack and a frequent cause of stroke. Caps are produced by smooth muscle cells (SMCs) that are recruited to the subendothelial space. We hypothesized that the recruitment mechanisms are likely common to embryonic artery development, which relies prominently on Notch signaling to form the subendothelial layers of medial SMCs.ObjectiveTo analyze the causal roles of the Notch signaling pathway in SMCs for atherogenesis and cap formation.Methods and ResultsNotch elements involved in arterial media development were found expressed in regions of fibrous cap in mouse plaques. To assess the causal role of Notch signaling in cap formation, we studied atherosclerosis in mice in which the Notch pathway was inactivated specifically in SMCs by conditional knockout of the essential effector transcription factor RBPJ. No major effects were observed on plaque size, but the presence of cap SMCs was significantly reduced. Lineage tracing revealed that the accumulation of SMC-derived plaque cells in the cap region was unaltered but that Notch-defective cells failed to re-acquire the SMC phenotype in the cap. To analyze whether the accumulation of SMC-derived cells in atherogenesis requires down-regulation of Notch signaling, we studied atherosclerosis in mice with constitutive Notch signaling in SMCs achieved by conditional expression of the Notch intracellular domain. Forced Notch signaling inhibited the ability of medial SMCs to contribute to plaque cells, including both cap SMCs and osteochondrogenic cells, and significantly reduced atherosclerosis development.ConclusionsSequential loss and gain of Notch signaling is needed to build the cap SMC population. The shared mechanisms with embryonic arterial media assembly suggest that the fibrous cap forms as a neo-media that restores the connection between endothelium and stabilizing SMCs, which is transiently disrupted by atherogenesis.

The Notch signalling pathway and breast cancer: The importance of balance and cellular self-control.

2019 ◽  
Vol 14 ◽  
Author(s):  
Germán Saucedo-Correa ◽  
Alejandro Bravo-Patiño ◽  
Rosa Elvira Núñez-Anita ◽  
Javier Oviedo-Boyso ◽  
Juan José Valdez-Alarcón ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Signaling Pathway ◽  
Cross Talk ◽  
Transcriptional Activation ◽  
Notch Pathway ◽  
Notch Signaling Pathway ◽  
Self Control ◽  
Design Strategies ◽  
Notch Intracellular Domain ◽  
The Cross

Notch is a cell-signaling pathway that is highly conserved in all metazoans and is responsible for cell differentiation and cross-talk communication with other signaling pathways such as WNT and Hh. In most cancers, the Notch signaling pathway is altered, causing atypical activity of vital processes such as cell cycle, differentiation and apoptosis, leading the cell to a carcinogenic state. Currently, the Notch signaling pathway has taken a special interest to design strategies in order to regulate the activity of this pathway since it is known that in the cancer molecular micro-environment the Notch pathway is over-expressed or presents an aberrant function, which, in consequence, corrupts the cross-talk communication with WNT and Hh pathways. Most of the existing strategies are focused on the systematic and whole inhibition of Notch pathway at the membrane level by the use of γ-secretases inhibitors. There are few strategies that act at the nuclear level inhibiting the activity of the transcriptional activation complex composed by the Notch intracellular domain, the transcriptional factor CSL and the Mastermind co-activator. In this review, by the fact that there are not any strategy focused to revert the over expression effect caused by the Notch pathway constitutive activity, we propose that the efforts to develop new strategies against cancer should be focused to understand the complexity of the cross-talk communication between Notch, WNT and Hh pathways to neutralize the gene aberrant activity characteristic of cancer cells which are responsible for those corrupted cross-talk communication.

scholarly journals Disruptions of Global and Jagged1-Mediated Notch Signaling Affect Thyroid Morphogenesis in the Zebrafish

Endocrinology ◽  
2012 ◽  
Vol 153 (11) ◽  
pp. 5645-5658 ◽  
Author(s):  
Patrizia Porazzi ◽  
Federica Marelli ◽  
Francesca Benato ◽  
Tiziana de Filippis ◽  
Davide Calebiro ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Notch Pathway ◽  
Genetic Alterations ◽  
Human Thyroid ◽  
Thyroid Cells ◽  
Notch Intracellular Domain ◽  
Molecular Events ◽  
And Function ◽  
Thyroid Development

Abstract The mechanisms underlying the early steps of thyroid development are largely unknown. In search for novel candidate genes implicated in thyroid function, we performed a gene expression analysis on thyroid cells revealing that TSH regulates the expression of several elements of the Notch pathway, including the ligand Jagged1. Because the Notch pathway is involved in cell-fate determination of several foregut-derived endocrine tissues, we tested its contribution in thyroid development using the zebrafish, a teleost model recapitulating the mammalian molecular events during thyroid development. Perturbing the Notch signaling (e.g. mib mutants, γ-secretase inhibition, or Notch intracellular domain overexpression), we obtained evidence that this pathway has a biological role during the earlier phases of thyroid primordium induction, limiting the number of cells that proceed to a specialized fate and probably involving actions from surrounding tissues. Moreover, we were able to confirm the expression of Jagged1 during different phases of zebrafish thyroid development, as well as in mouse and human thyroid tissues. The two orthologues to the single jagged1 gene (JAG1) in humans, jag1a and jag1b, are expressed with different spatiotemporal patterns in the developing zebrafish thyroid. Both jag1a and jag1b morphants, as well as jag1b mutant fish line, display thyroid hypoplasia and impaired T4 production; this thyroid phenotype was rescued by coinjection of human JAG1 mRNA. In conclusion, Notch pathway is involved in the early steps of thyroid morphogenesis, and Jagged1-Notch signal is required for zebrafish thyroid development and function. Thus, genetic alterations affecting the Notch pathway may confer susceptibility for thyroid dysgenesis.

scholarly journals Notch Intracellular Domain Plasmid Delivery via Poly(Lactic-Co-Glycolic Acid) Nanoparticles to Upregulate Notch Pathway Molecules

2021 ◽  
Vol 8 ◽  
Author(s):  
Victoria L. Messerschmidt ◽  
Uday Chintapula ◽  
Aneetta E. Kuriakose ◽  
Samantha Laboy ◽  
Thuy Thi Dang Truong ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Glycolic Acid ◽  
Umbilical Vein ◽  
Notch Pathway ◽  
Cellular Functions ◽  
Intracellular Domain ◽  
Downstream Signaling ◽  
Notch Intracellular Domain ◽  
Downstream Effects ◽  
Umbilical Vein Endothelial Cells

Notch signaling is a highly conserved signaling system that is required for embryonic development and regeneration of organs. When the signal is lost, maldevelopment occurs and leads to a lethal state. Delivering exogenous genetic materials encoding Notch into cells can reestablish downstream signaling and rescue cellular functions. In this study, we utilized the negatively charged and FDA approved polymer poly(lactic-co-glycolic acid) to encapsulate Notch Intracellular Domain-containing plasmid in nanoparticles. We show that primary human umbilical vein endothelial cells (HUVECs) readily uptake the nanoparticles with and without specific antibody targets. We demonstrated that our nanoparticles are non-toxic, stable over time, and compatible with blood. We further demonstrated that HUVECs could be successfully transfected with these nanoparticles in static and dynamic environments. Lastly, we elucidated that these nanoparticles could upregulate the downstream genes of Notch signaling, indicating that the payload was viable and successfully altered the genetic downstream effects.

The Notch Signaling Pathway as a Suppressor of Myeloid Transformation

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. SCI-13-SCI-13
Author(s):  
Iannis Aifantis
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
Notch Signaling ◽  
Conflicts Of Interest ◽  
Lymphoblastic Leukemia ◽  
Notch Pathway ◽  
Stem Cell Differentiation ◽  
Lineage Tracing ◽  
Specific Gene ◽  
Hematopoietic Stem

Abstract Abstract SCI-13 Notch signaling is a central regulator of differentiation in a variety of organisms and tissue types. Its activity is controlled by the multi-subunit γ-secretase complex (γSE) complex. Although Notch signaling can play both oncogenic and tumor suppressor roles in solid tumors, in the hematopoietic system, it is exclusively oncogenic, notably in T cell acute lymphoblastic leukemia (T-ALL), a disease characterized by Notch1 activating mutations. We identified somatic inactivating Notch pathway mutations in a fraction of chronic myelomonocytic leukemia (CMML) patients. Inactivation of Notch signaling in mouse hematopoietic stem cells (HSC) results in an aberrant accumulation of granulocyte/monocyte progenitors (GMP), extramedullary hematopoieisis and the induction of CMML-like disease. Transcriptome analysis reveals that Notch signaling regulates an extensive myelomonocytic-specific gene signature, through the direct suppression of gene transcription by the Notch target Hes1. These studies identify a novel role for Notch signaling during early hematopoietic stem cell differentiation and suggest that the Notch pathway can play both tumor-promoting and suppressive roles within the same tissue. These observations also suggest that Notch activity is not simply a promoter of the T cell lineage in the thymus but that Notch signaling thresholds could regulate commitment and/or survival of distinct hematopoietic lineages in the bone marrow. To address these issues in vivo, we have generated Notch receptor lineage tracing and activity reporter genetic tools. Analysis of these animal models identified unique novel functions for the Notch pathway during early bone marrow hematopoiesis. Disclosures: No relevant conflicts of interest to declare.

scholarly journals The Notch Intracellular Domain Can Function as a Coactivator for LEF-1

2001 ◽  
Vol 21 (22) ◽  
pp. 7537-7544 ◽  
Author(s):  
David A. Ross ◽  
Tom Kadesch
Keyword(s):  
Notch Signaling ◽  
Wnt Signaling Pathway ◽  
Notch Pathway ◽  
High Mobility ◽  
In Vitro Assays ◽  
Transactivation Domain ◽  
Intracellular Domain ◽  
Notch Intracellular Domain

ABSTRACT Notch signaling commences with two ligand-mediated proteolysis events that release the Notch intracellular domain, NICD, from the plasma membrane. NICD then translocates into the nucleus and interacts with the DNA binding protein CSL to activate transcription. We found that NICD expression also potentiates activity of the transcription factor LEF-1. NICD stimulation of LEF-1 activity was context dependent and occurred on a subset of promoters distinct from those activated by β-catenin. Importantly, the effect of NICD does not appear to be mediated through canonical components of the Wnt signaling pathway or downstream components of the Notch pathway. In vitro assays show a weak association between the C-terminal transactivation domain of NICD and the high-mobility group domain of LEF-1, suggesting that the two proteins interact in vivo. Our data therefore describe a new nuclear target of Notch signaling and a new coactivator for LEF-1.

Abstract 254: Platelet Derived Growth Factor Receptor Beta Activation Promotes Atheroprotective Changes in Smooth Muscle Cell Phenotype

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Alexandra A Newman ◽  
Olga A Cherepanova ◽  
Gary K Owens
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Plaque Rupture ◽  
Growth Factor Receptor ◽  
Lineage Tracing ◽  
Conditional Knockout ◽  
Platelet Derived Growth Factor ◽  
Fibrous Cap ◽  
Pdgfr Beta ◽  
Receptor Beta

Despite decades of research, little is known about mechanisms and factors driving atherosclerotic progression leading to plaque rupture, thrombosis and myocardial infarction or stroke. The widely accepted dogma is a thin fibrous cap and a paucity of Acta2+ smooth muscle cells (SMC) relative to macrophages increases risk of plaque rupture. However, our recent rigorous lineage tracing studies in advanced lesions showed a subset of cells that express macrophage markers are SMC-derived and SMC specific conditional knockout of stem pluripotency gene Klf4 resulted in increased fibrous cap thickness and decreased lesion size and abundance of SMC-derived macrophage-like cells. Results indicate that SMC play a critical role in lesion pathogenesis but paradoxically can transition to a beneficial or detrimental state, presumably as a function of the local environmental milieu within lesions. Studies highlight the critical need to identify factors and mechanisms that direct SMC to form a stable fibrous cap. Various in vitro data show that SMC treated with platelet derived growth factor receptor beta (PDGFR beta) ligands dedifferentiate, proliferate, and synthesize extracellular matrix (ECM) molecules, including collagens known to be enriched within the fibrous cap. We hypothesize that PDGFR beta activation in SMC is necessary for fibrous cap stabilization through EMC protein synthesis. Herein we employ Myh11-ER T2 -cre eYFP SMC lineage tracing ApoE-/- Western diet fed mice to show that a subset of SMC in advanced lesions express PDGFR beta and are localized to the fibrous cap. Moreover we demonstrate that SMC specific conditional KO of the PDGFR beta in these lineage tracing mice resulted in dramatic reductions in the numbers of YFP+ (SMC-derived) cells within lesions but an increase in YFP- (not SMC-derived) macrophages, as well as a decrease in Acta2+ cells in the fibrous cap. Results indicate that PDGFR beta activation in SMC is a critical determinant of the cellular composition of lesions and is essential for investment of SMC within the fibrous cap. Supported by NIH R01 grants HL121008 and HL087867 to GKO.

scholarly journals Notch Signaling Regulation in HCC: From Hepatitis Virus to Non-Coding RNAs

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 521
Author(s):  
Catia Giovannini ◽  
Francesca Fornari ◽  
Fabio Piscaglia ◽  
Laura Gramantieri
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Hepatitis Virus ◽  
Notch Pathway ◽  
Notch Receptor ◽  
Gamma Secretase ◽  
Stem Cell Maintenance ◽  
Pathway Activation ◽  
Promising Therapeutic Approach ◽  
Conserved Genes

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.

Notch restricts lymphatic vessel sprouting induced by vascular endothelial growth factor

Blood ◽  
2011 ◽  
Vol 118 (4) ◽  
pp. 1154-1162 ◽  
Author(s):  
Wei Zheng ◽  
Tuomas Tammela ◽  
Masahiro Yamamoto ◽  
Andrey Anisimov ◽  
Tanja Holopainen ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Target Genes ◽  
Notch Pathway ◽  
Lymphatic Vessels ◽  
Soluble Form ◽  
Fibrin Gel ◽  
3 Dimensional ◽  
Endothelial Growth Factor

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.

scholarly journals Notch Signaling Is Involved in Expression of Thyrocyte Differentiation Markers and Is Down-Regulated in Thyroid Tumors

2008 ◽  
Vol 93 (10) ◽  
pp. 4080-4087 ◽  
Author(s):  
E. Ferretti ◽  
E. Tosi ◽  
A. Po ◽  
A. Scipioni ◽  
R. Morisi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Thyroid Cancer ◽  
Notch Signaling ◽  
Notch Pathway ◽  
Human Thyroid ◽  
Thyroid Tumors ◽  
Follicular Cells ◽  
Differentiation Markers ◽  
Thyroid Follicular Cells ◽  
Thyroid Cancer Cells

Context: Notch genes encode receptors for a signaling pathway that regulates cell growth and differentiation in various contexts, but the role of Notch signaling in thyroid follicular cells has never been fully published. Objective: The objective of the study was to characterize the expression of Notch pathway components in thyroid follicular cells and Notch signaling activities in normal and transformed thyrocytes. Design/Setting and Patients: Expression of Notch pathway components and key markers of thyrocyte differentiation was analyzed in murine and human thyroid tissues (normal and tumoral) by quantitative RT-PCR and immunohistochemistry. The effects of Notch overexpression in human thyroid cancer cells and FTRL-5 cells were explored with analysis of gene expression, proliferation assays, and experiments involving transfection of a luciferase reporter construct containing human NIS promoter regions. Results: Notch receptors are expressed during the development of murine thyrocytes, and their expression levels parallel those of thyroid differentiation markers. Notch signaling characterized also normal adult thyrocytes and is regulated by TSH. Notch pathway components are variably expressed in human normal thyroid tissue and thyroid tumors, but expression levels are clearly reduced in undifferentiated tumors. Overexpression of Notch-1 in thyroid cancer cells restores differentiation, reduces cell growth rates, and stimulates NIS expression via a direct action on the NIS promoter. Conclusion: Notch signaling is involved in the determination of thyroid cell fate and is a direct regulator of thyroid-specific gene expression. Its deregulation may contribute to the loss of differentiation associated with thyroid tumorigenesis.

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