scholarly journals Dual Role of Jam3b in Early Hematopoietic and Vascular Development

2019 ◽  
Author(s):  
Isao Kobayashi ◽  
Jingjing Kobayashi-Sun ◽  
Yuto Hirakawa ◽  
Madoka Ouchi ◽  
Koyuki Yasuda ◽  
...  

AbstractIn order to efficiently derive hematopoietic stem cells (HSCs) from pluripotent precursors, it is crucial to understand how mesodermal cells acquire hematopoietic or endothelial identity due to their close developmental connection. Although Npas4 has been recently identified as a conserved master regulator of hemato-vascular development, the molecular mechanisms underlying the cell fate divergence between hematopoietic and vascular endothelial cells are still unclear. Here, we show in zebrafish that the divergence of hematopoietic and vascular endothelial cells in mesodermal cells is regulated by Junctional adhesion molecule 3b (Jam3b) via two independent signaling pathways. Mutation of jam3b led to the reduction of npas4l expression in the posterior lateral plate mesoderm and defect of both hematopoietic and vascular development. Mechanistically, we uncover that Jam3b promotes endothelial specification by regulating npas4l expression through the repression of the Rap1a-Erk signaling cascade. Jam3b subsequently promotes hematopoietic development including HSCs by regulating lrrc15 expression in endothelial precursors through the activation of an integrin-dependent signaling cascade. Our data provide insight into the divergent mechanisms for instructing hematopoietic or vascular fates from mesodermal cells.

2021 ◽  
Vol 22 (6) ◽  
pp. 2804
Author(s):  
Yasuo Yoshitomi ◽  
Takayuki Ikeda ◽  
Hidehito Saito-Takatsuji ◽  
Hideto Yonekura

Blood vessels are essential for the formation and maintenance of almost all functional tissues. They play fundamental roles in the supply of oxygen and nutrition, as well as development and morphogenesis. Vascular endothelial cells are the main factor in blood vessel formation. Recently, research findings showed heterogeneity in vascular endothelial cells in different tissue/organs. Endothelial cells alter their gene expressions depending on their cell fate or angiogenic states of vascular development in normal and pathological processes. Studies on gene regulation in endothelial cells demonstrated that the activator protein 1 (AP-1) transcription factors are implicated in angiogenesis and vascular development. In particular, it has been revealed that JunB (a member of the AP-1 transcription factor family) is transiently induced in endothelial cells at the angiogenic frontier and controls them on tip cells specification during vascular development. Moreover, JunB plays a role in tissue-specific vascular maturation processes during neurovascular interaction in mouse embryonic skin and retina vasculatures. Thus, JunB appears to be a new angiogenic factor that induces endothelial cell migration and sprouting particularly in neurovascular interaction during vascular development. In this review, we discuss the recently identified role of JunB in endothelial cells and blood vessel formation.


Blood ◽  
2010 ◽  
Vol 116 (13) ◽  
pp. 2395-2401 ◽  
Author(s):  
Jan Kazenwadel ◽  
Michael Z. Michael ◽  
Natasha L. Harvey

Abstract The specification of arterial, venous, and lymphatic endothelial cell fate is critical during vascular development. Although the homeobox transcription factor, Prox1, is crucial for the specification and maintenance of lymphatic endothelial cell identity, little is known regarding the mechanisms that regulate Prox1 expression. Here we demonstrate that miR-181a binds the 3′ untranslated region of Prox1, resulting in translational inhibition and transcript degradation. Increased miR-181a activity in primary embryonic lymphatic endothelial cells resulted in substantially reduced levels of Prox1 mRNA and protein and reprogramming of lymphatic endothelial cells toward a blood vascular phenotype. Conversely, treatment of primary embryonic blood vascular endothelial cells with miR-181a antagomir resulted in increased Prox1 mRNA levels. miR-181a expression is significantly higher in embryonic blood vascular endothelial cells compared with lymphatic endothelial cells, suggesting that miR-181 activity could be an important mechanism by which Prox1 expression is silenced in the blood vasculature during development. Our work is the first example of a microRNA that targets Prox1 and has implications for the control of Prox1 expression during vascular development and neo-lymphangiogenesis.


Author(s):  
Can Huang ◽  
Dawei Yang ◽  
George W. Ye ◽  
Charles A. Powell ◽  
Peipei Guo

Canonical Notch signaling is one of the most conserved signaling cascades. It regulates cell proliferation, cell differentiation, and cell fate maintenance in a variety of biological systems during development and cancer (Fortini, 2009; Kopan and Ilagan, 2009; Andersson et al., 2011; Ntziachristos et al., 2014). For the hematopoietic system, during embryonic development, Notch1 is essential for the emergence of hematopoietic stem cells (HSCs) at the aorta-gornado-mesonephro regions of the dorsal aorta. At adult stage, Notch receptors and Notch targets are expressed at different levels in diverse hematopoietic cell types and influence lineage choices. For example, Notch specifies T cell lineage over B cells. However, there has been a long-lasting debate on whether Notch signaling is required for the maintenance of adult HSCs, utilizing transgenic animals inactivating different components of the Notch signaling pathway in HSCs or niche cells. The aims of the current mini-review are to summarize the evidence that disapproves or supports such hypothesis and point at imperative questions waiting to be addressed; hence, some of the seemingly contradictory findings could be reconciled. We need to better delineate the Notch signaling events using biochemical assays to identify direct Notch targets within HSCs or niche cells in specific biological context. More importantly, we call for more elaborate studies that pertain to whether niche cell type (vascular endothelial cells or other stromal cell)-specific Notch ligands regulate the differentiation of T cells in solid tumors during the progression of T-lymphoblastic lymphoma (T-ALL) or chronic myelomonocytic leukemia (CMML). We believe that the investigation of vascular endothelial cells' or other stromal cell types' interaction with hematopoietic cells during homeostasis and stress can offer insights toward specific and effective Notch-related therapeutics.


Author(s):  
Márta L. Debreczeni ◽  
Zsuzsanna Németh ◽  
Erika Kajdácsi ◽  
Henriette Farkas ◽  
László Cervenak

AbstractIn the last few decades, a substantial body of evidence underlined the pivotal role of bradykinin in certain types of angioedema. The formation and breakdown of bradykinin has been studied thoroughly; however, numerous questions remained open regarding the triggering, course, and termination of angioedema attacks. Recently, it became clear that vascular endothelial cells have an integrative role in the regulation of vessel permeability. Apart from bradykinin, a great number of factors of different origin, structure, and mechanism of action are capable of modifying the integrity of vascular endothelium, and thus, may participate in the regulation of angioedema formation. Our aim in this review is to describe the most important permeability factors and the molecular mechanisms how they act on endothelial cells. Based on endothelial cell function, we also attempt to explain some of the challenging findings regarding bradykinin-mediated angioedema, where the function of bradykinin itself cannot account for the pathophysiology. By deciphering the complex scenario of vascular permeability regulation and edema formation, we may gain better scientific tools to be able to predict and treat not only bradykinin-mediated but other types of angioedema as well.


2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Chih-Wen Ni ◽  
Tom Smith ◽  
Nathan D Lawson

Gata2 is a transcription factor implicated in hematopoietic development. Previously, we utilized zinc-finger nucleases to generate a zebrafish mutant in gata2a, which reveals a novel role for this gene in vascular development. In particular, gata2a mutant embryos exhibit defects in blood flow circulation due to the formation of shunts within trunk blood vessels, although artery and vein identity appears normal. Here, we show that endothelial cells in gata2a mutant embryos specifically undergo apoptosis as revealed by positive staining of activated caspase-3 at 30hpf but not 24hpf. This endothelial apoptosis can be rescued by re-constitution of gata2a or overexpression of a well-known anti-apoptotic protein, bcl2l1. Interestingly, knocking-down p53 has no effect on the rescue of apoptosis in gata2a mutants, suggesting a p53 independent pathway of apoptosis. Furthermore, we find that mouse retinal vascular endothelial cells lacking gata2 also appear to undergo apoptosis, which prevent angiogenic sprouting from the superficial to media layer of retina vasculature. These findings reveal a new role of gata2 in vascular development whereby gata2 retains an anti-apoptotic function in endothelial cells.


2015 ◽  
Vol 88 (3) ◽  
pp. 247-252 ◽  
Author(s):  
Mihaela Elena Marina ◽  
Iulia Ioana Roman ◽  
Anne-Marie Constantin ◽  
Carmen Mihaela Mihu ◽  
Alexandru Dumitru Tătaru

Vascular endothelial growth factor (VEGF) is a key growth factor, regulating the neovascularization, during embryogenesis, skeletal growth, reproductive functions and pathological processes. The VEGF receptors (VEGFR) are present in endothelial cells and other cell types, such as vascular smooth muscle cells, hematopoietic stem cells, monocytes, neurons, macrophages, and platelets.Angiogenesis is initiated by the activation of vascular endothelial cells through several factors. The excess dermal vascularity and VEGF production are markers of psoriasis.The pathological role of VEGF/VEGFR signaling during the psoriasis onset and evolution makes it a promising target for the treatment of psoriasis. Antibodies and other types of molecules targeting the VEGF pathway are currently evaluated in arresting the evolution of psoriasis.


1999 ◽  
Vol 82 (S 01) ◽  
pp. 27-31
Author(s):  
Cam Patterson

SummaryThe molecular mechanisms regulating the development of vascular diseases such as atherosclerosis remain poorly understood at present. Similarities between genetic programs observed during the course of vascular disease with those observed during vascular development suggest that developmental processes are recapitulated in vascular disease. The earliest event in vascular development is the differentiation of endothelial cells from their mesodermally-derived hamangioblastic precursors. The receptor for vascular endothelial growth factor, KDR/flk-1, plays a critical role in these earliest stages of vascular development. During development and in the adult, expression of this receptor is restricted to vascular endothelial cells and their immediate precursors. We have therefore endeavored to determine the transcriptional events regulating KDR/flk-1 expression, with the hope of gaining insight into processes of vascular development that might also be important in vascular diseases of the adult.


Angiogenesis ◽  
2021 ◽  
Author(s):  
Giovanni Canu ◽  
Christiana Ruhrberg

AbstractHematopoiesis in vertebrate embryos occurs in temporally and spatially overlapping waves in close proximity to blood vascular endothelial cells. Initially, yolk sac hematopoiesis produces primitive erythrocytes, megakaryocytes, and macrophages. Thereafter, sequential waves of definitive hematopoiesis arise from yolk sac and intraembryonic hemogenic endothelia through an endothelial-to-hematopoietic transition (EHT). During EHT, the endothelial and hematopoietic transcriptional programs are tightly co-regulated to orchestrate a shift in cell identity. In the yolk sac, EHT generates erythro-myeloid progenitors, which upon migration to the liver differentiate into fetal blood cells, including erythrocytes and tissue-resident macrophages. In the dorsal aorta, EHT produces hematopoietic stem cells, which engraft the fetal liver and then the bone marrow to sustain adult hematopoiesis. Recent studies have defined the relationship between the developing vascular and hematopoietic systems in animal models, including molecular mechanisms that drive the hemato-endothelial transcription program for EHT. Moreover, human pluripotent stem cells have enabled modeling of fetal human hematopoiesis and have begun to generate cell types of clinical interest for regenerative medicine.


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