Gene Regulation and Arteriosclerosis: Are Developmental Programs Reactivated in Vascular Disease?

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.

2009 ◽  
Vol 118 (5) ◽  
pp. 341-349 ◽  
Author(s):  
Philip Newsholme ◽  
Paulo I. Homem De Bittencourt ◽  
Ciara O' Hagan ◽  
Giuseppe De Vito ◽  
Colin Murphy ◽  
...  

It is now widely accepted that hypertension and endothelial dysfunction are associated with an insulin-resistant state and thus with the development of T2DM (Type 2 diabetes mellitus). Insulin signalling is impaired in target cells and tissues, indicating that common molecular signals are involved. The free radical NO• regulates cell metabolism, insulin signalling and secretion, vascular tone, neurotransmission and immune system function. NO• synthesis is essential for vasodilation, the maintenance of blood pressure and glucose uptake and, thus, if levels of NO• are decreased, insulin resistance and hypertension will result. Decreased blood levels of insulin, increased AngII (angiotensin II), hyperhomocysteinaemia, increased ADMA (asymmetric ω-NG,NG-dimethylarginine) and low plasma L-arginine are all conditions likely to decrease NO• production and which are associated with diabetes and cardiovascular disease. We suggest in the present article that the widely reported beneficial effects of exercise in the improvement of metabolic and cardiovascular health are mediated by enhancing the flux of muscle- and kidney-derived amino acids to pancreatic and vascular endothelial cells aiding the intracellular production of NO•, therefore resulting in normalization of insulin secretion, vascular tone and insulin sensitivity. Exercise may also have an impact on AngII and ADMA signalling and the production of pro- and anti-inflammatory cytokines in muscle, so reducing the progression and development of vascular disease and diabetes. NO• synthesis will be increased during exercise in the vascular endothelial cells so promoting blood flow. We suggest that exercise may promote improvements in health due to positive metabolic and cytokine-mediated effects.


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.


2018 ◽  
Vol 315 (5) ◽  
pp. H1477-H1485 ◽  
Author(s):  
Kimiko Yamamoto ◽  
Hiromi Imamura ◽  
Joji Ando

Vascular endothelial cells (ECs) sense and transduce hemodynamic shear stress into intracellular biochemical signals, and Ca2+ signaling plays a critical role in this mechanotransduction, i.e., ECs release ATP in the caveolae in response to shear stress and, in turn, the released ATP activates P2 purinoceptors, which results in an influx into the cells of extracellular Ca2+. However, the mechanism by which the shear stress evokes ATP release remains unclear. Here, we demonstrated that cellular mitochondria play a critical role in this process. Cultured human pulmonary artery ECs were exposed to controlled levels of shear stress in a flow-loading device, and changes in the mitochondrial ATP levels were examined by real-time imaging using a fluorescence resonance energy transfer-based ATP biosensor. Immediately upon exposure of the cells to flow, mitochondrial ATP levels increased, which was both reversible and dependent on the intensity of shear stress. Inhibitors of the mitochondrial electron transport chain and ATP synthase as well as knockdown of caveolin-1, a major structural protein of the caveolae, abolished the shear stress-induced mitochondrial ATP generation, resulting in the loss of ATP release and influx of Ca2+ into the cells. These results suggest the novel role of mitochondria in transducing shear stress into ATP generation: ATP generation leads to ATP release in the caveolae, triggering purinergic Ca2+ signaling. Thus, exposure of ECs to shear stress seems to activate mitochondrial ATP generation through caveola- or caveolin-1-mediated mechanisms. NEW & NOTEWORTHY The mechanism of how vascular endothelial cells sense shear stress generated by blood flow and transduce it into functional responses remains unclear. Real-time imaging of mitochondrial ATP demonstrated the novel role of endothelial mitochondria as mechanosignaling organelles that are able to transduce shear stress into ATP generation, triggering ATP release and purinoceptor-mediated Ca2+ signaling within the cells.


1983 ◽  
Vol 60 (1) ◽  
pp. 89-102
Author(s):  
D de Bono ◽  
C. Green

The interactions between human or bovine vascular endothelial cells and fibroblast-like vascular intimal spindle-shaped cells have been studied in vitro, using species-specific antibodies to identify the different components in mixed cultures. Pure cultures of endothelial cells grow as uniform, nonoverlapping monolayers, but this growth pattern is lost after the addition of spindle cells, probably because the extracellular matrix secreted by the latter causes the endothelial cells to modify the way they are attached to the substrate. The result is a network of tubular aggregates of endothelial cells in a three-dimensional ‘polylayer’ of spindle-shaped cells. On the other hand, endothelial cells added to growth-inhibited cultures of spindle-shaped cells will grow in sheets over the surface of the culture. Human endothelial cells grown in contact with spindle-shaped cells have a reduced requirement for a brain-derived endothelial growth factor. The interactions of endothelial cells and other connective tissue cells in vitro may be relevant to the mechanisms of endothelial growth and blood vessel formation in vivo, and emphasize the potential importance of extracellular matrix in controlling endothelial cell behaviour.


2020 ◽  
Vol 78 (3) ◽  
pp. 383-389 ◽  
Author(s):  
Yiwei Zhao ◽  
Peile Ren ◽  
Qiufang Li ◽  
Shafiu Adam Umar ◽  
Tan Yang ◽  
...  

Abstract Atherosclerosis is a significant cause of mortality and morbidity. Studies suggest that the chemokine receptor CX3CR1 plays a critical role in atherogenesis. Shear stress is an important mechanical force that affects blood vessel function. In this study, we investigated the effect of shear stress on CX3CR1 expression in vascular endothelial cells (VECs). First, cells were exposed to different shear stress and then CX3CR1 mRNA and protein were measured by quantitative RT-PCR and western blot analysis, respectively. CX3CR1 gene silencing was used to analyze the molecular mechanisms underlying shear stress-mediated effects on CX3CR1 expression. CX3CR1 mRNA and protein expression were significantly increased with 4.14 dyne/cm2 of shear stress compared with other tested levels of shear stress. We observed a significant increase in CX3CR1 mRNA levels at 2 h and CX3CR1 protein expression at 4 h. CX3CR1-induced VCAM-1 expression in response to low shear stress by activating NF-κB signaling pathway in VECs. Our findings demonstrate that low shear stress increases CX3CR1 expression, which increases VCAM-1 expression due to elevated NF-κB activation. The current study provides evidence of the correlation between shear stress and atherosclerosis mediated by CX3CR1.


2012 ◽  
Vol 40 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Gillian R. Milne ◽  
Timothy M. Palmer ◽  
Stephen J. Yarwood

Chronic inflammatory diseases, such as atherosclerosis, are a major cause of death and disability in the developed world. In this respect, although cholesterol obviously plays a predominant role in atherosclerosis, targeting inflammation at lesion sites may be just as important. Indeed, elevated IL-6 (interleukin 6) levels are as strongly associated with coronary heart disease as increased cholesterol. We have been investigating novel cAMP-regulated pathways that combat the action of pro-inflammatory cytokines, such as IL-6 and leptin, in the VECs (vascular endothelial cells) of the circulatory system. In this respect, we have begun to unravel new molecular mechanisms by which the cAMP/Epac1 (exchange protein directly activated by cAMP 1)/Rap1 pathway can initiate a rigorous programme of protective anti-inflammatory responses in VECs. Central to this is the coupling of cAMP elevation to the mobilization of two C/EBP (CCAAT/enhancer-binding protein) family transcription factors, resulting in the induction of the SOCS3 (suppressor of cytokine signalling 3) gene, which attenuates pro-inflammatory cytokine signalling in VECs. These novel ‘protective’ mechanisms of cAMP action will inform the development of the next generation of pharmaceuticals specifically designed to combat endothelial inflammation associated with cardiovascular disease.


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