scholarly journals Notch Regulation of Hematopoiesis, Endothelial Precursor Cells, and Blood Vessel Formation: Orchestrating the Vasculature

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Vincenza Caolo ◽  
Daniel G. M. Molin ◽  
Mark J. Post

The development of the vascular system begins with the formation of hemangioblastic cells, hemangioblasts, which organize in blood islands in the yolk sac. The hemangioblasts differentiate into hematopoietic and angioblastic cells. Subsequently, the hematopoietic line will generate blood cells, whereas the angioblastic cells will give rise to vascular endothelial cells (ECs). In response to specific molecular and hemodynamic stimuli, ECs will acquire either arterial or venous identity. Recruitment towards the endothelial tubes and subsequent differentiation of pericyte and/or vascular smooth muscle cells (vSMCs) takes place and the mature vessel is formed. The Notch signaling pathway is required for determining the arterial program of both endothelial and smooth muscle cells; however, it is simultaneously involved in the generation of hematopoietic stem cells (HSCs), which will give rise to hematopoietic cells. Notch signaling also regulates the function of endothelial progenitor cells (EPCs), which are bone-marrow-derived cells able to differentiate into ECs and which could be considered the adult correlate of the angioblast. In addition, Notch signaling has been reported to control sprouting angiogenesis during blood vessels formation in the adult. In this paper we discuss the physiological role of Notch in vascular development, providing an overview on the involvement of Notch in vascular biology from hematopoietic stem cell to adaptive neovascularization in the adult.

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Takehisa Shimizu ◽  
Toru Tanaka ◽  
Tatsuya Iso ◽  
Masahiko Kurabayashi

Vascular calcification is a prominent feature of atherosclerosis and closely correlated with cardiovascular morbidity and mortality. In this study, we hypothesize that Notch signaling plays an important role in osteogenic conversion of smooth muscle cells (SMCs) and vascular calcification. <Methods and Results> Either Notch ligand-expressing cells or overexpression of Notch intracellular domains (NICDs) induced expression of Msx2, a key regulator of osteogenic conversion, in human aortic SMCs (HASMCs). In addition, overexpression of Notch1 intracellular domain (N1-ICD) markedly upregulated alkaline phosphatase (ALP) activity and matrix mineralization of HASMCs. A knockdown experiment with a small interfering RNA confirmed that Msx2, but not Runx2/Cbfa1, another key osteogenic transcription factor, is responsible for Notch1-induced osteogenic conversion of HASMCs. Furthermore, this Notch1-Msx2 pathway was independent of bone morphogenetic protein-2 (BMP-2), an osteogenic morphogen upstream of Msx2. The transcriptional activity of the Msx2 promoter was significantly enhanced by Notch ligands stimulation, whereas it was abrogated by a specific Notch signaling inhibitor. The RBP-Jk binding element within the Msx2 promoter was critical to Notch1-induced Msx2 gene expression, and correspondingly, neither N1-ICD overexpression nor Notch ligands stimulation increase the Msx2 expression or transcriptional activity of the Msx2 promoter, respectively, in RBP-Jk-deficient fibroblasts. Immunohistochemistry of human artery specimens revealed colocalization of Notch1 and Msx2 within atherosclerotic plaques, indicating a role of Notch1-Msx2 pathway in vascular calcification in vivo. These results suggest that Notch signaling directly targets Msx2, thus accelerating osteogenic conversion of HASMCs and, as a result, a formation of vascular calcification.


Oncotarget ◽  
2017 ◽  
Vol 8 (44) ◽  
pp. 76165-76173 ◽  
Author(s):  
Hongping Xu ◽  
Liwei Zhang ◽  
Wei Chen ◽  
Jiazhou Xu ◽  
Ruting Zhang ◽  
...  

2005 ◽  
Vol 53 (2) ◽  
pp. 187-196 ◽  
Author(s):  
Martina Wendel ◽  
Wolfgang Kummer ◽  
Lilla Knels ◽  
Joachim Schmeck ◽  
Thea Koch

The endothelin/endothelin-receptor system is a key player in the regulation of vascular tone in mammals. We raised and characterized an antiserum against rat ETB receptor and investigated the distribution of ETB receptors in different vascular beds during postnatal development (day 0 through day 28) and in the adult rat. We report the tissue-specific and age-dependent presence of vasoconstrictor ETB receptors. At the time of birth, vascular smooth muscle cells from all tissues examined did not exhibit ETB receptor immunoreactivity. The occurrence of ETB receptor immunoreactivity in the postnatal development was time dependent and started in small coronary and meningeal arteries at day 5, followed by small mesenteric arteries as well as brachial artery and vein at day 14. At day 21, ETB receptors were present in the media of muscular segments of pulmonary artery, large coronary arteries, and intracerebral arterioles. At day 28, ETB receptor immunoreactivity was evident in interlobular renal arteries, vas afferens, and efferens. Large renal arteries, mesenteric artery, and elastic segments of pulmonary arteries, as well as coronary and mesenteric veins, did not exhibit ETB receptor immunoreactivity. These data demonstrate the age-dependent and tissue-specific presence of ETB receptors, mainly on arterial smooth muscle cells in the vascular system of the rat.


1999 ◽  
Vol 277 (2) ◽  
pp. H515-H523 ◽  
Author(s):  
Nobuya Fujita ◽  
Yusuke Furukawa ◽  
Naoki Itabashi ◽  
Yasushi Tsuboi ◽  
Michio Matsuda ◽  
...  

The physiological role of the vasoconstrictive hormones arginine vasopressin (AVP) and angiotensin II (ANG II) in the development of vascular hyperplasia is still unclear. We examined the effects of these hormones on cell cycle regulation of cultured rat vascular smooth muscle cells (VSMC). AVP and ANG II were able to induce G1/S transition and DNA synthesis in serum-starved quiescent VSMC but failed to promote further progression into G2/M phases. AVP and ANG II enhanced the expression and activity of cdk2, cyclin E, and proliferating cell nuclear antigen but did not induce expression of cdc2/cyclin B complex, a critical regulator of G2/M transition. The failure of cdc2 mRNA induction was found to be caused by a defect in cdc2 promoter activation. Binding of free E2F-1 to the cdc2 promoter did not occur in hormone-treated VSMC, which may account for the defective induction of cdc2. The absence of cdc2 promoter activation and G2/M transition may be important for the prevention of hyperplasia under physiological conditions but underlies the hypertrophy of VSMC.


1975 ◽  
Author(s):  
V. Noordhoek Hegt

Endothelial plasminogen activator activity in different types of human blood vessels obtained from fifty necropsies and thirty-five biopsies was detected and localized by means of plasminogen-rich fibrin slides. Great differences in endothelial activator activity were found along and across (vasa vasorum) the wall of the human vascular system.The same blood vessels were simultaneously investigated by a modified fibrin slide technique using plasminogen-free fibrin slides covered by plasmin to detect and localize inhibition of fibrinolysis in the vascular wall. The great variation in plasmin inhibition in different vessels revealed by this “fibrin slide sandwich technique” appeared to be closely associated with the localization and number of smooth muscle cells present in the walls of the vascular system. Strong plasmin inhibition was generally found at sites which showed no activator activity with the regular fibrin slide technique, while areas with a high endothelial fibrinolytic activity mostly revealed no inhibitory capacity.These results indicate that much of the variation in endothelial fibrinolytic activity on fibrin slides is due to inhibitory effects from the surrounding smooth muscle cells rather than to variability in the plasminogen activator content of the endothelium itself.


1987 ◽  
Vol 253 (1) ◽  
pp. C71-C78 ◽  
Author(s):  
Y. Sasaki ◽  
Y. Sasaki ◽  
K. Kanno ◽  
H. Hidaka

To assess the physiological role of intracellular Ca2+ in the organization of actin microfilaments in smooth muscle cells, we employed several types of Ca2+ antagonists. The rabbit aortic smooth muscle cells treated with the putative intracellular Ca2+ antagonist 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxybenzoate (TMB 8) at 5-100 microM showed a loss or a decrease in size and length of the actin-containing microfilament structure in a dose-dependent manner. Similar disorganization of actin structure was observed in the smooth muscle cells treated with 1-(5-isoquinolinesulfonyl)-homopiperazine (HA 1077) at 5-100 microM, which is a new type of Ca2+ antagonist different from Ca2+ entry blocker. In contrast, 100 microM verapamil and diltiazem induced no reorganization of the actin microfilament structure. Antimycin A decreased the ATP levels in smooth muscle cells and disorganized the actin-containing structure. Unlike antimycin A, TMB 8 and HA 1077 did not lower the ATP level below the threshold needed to maintain the actin filament structure. Both TMB 8 and HA 1077 directly interacted with neither the actin monomer nor F-actin in a viscometrical assay system. Thus these reagents may induce the disorganization of actin microfilament structure in smooth muscle cells through the indirect reaction(s) with the actin, suggesting that an appropriate level of ATP and Ca2+ and/or its involving reactions may be essential for maintenance of the actin structure.


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