scholarly journals Enhanced angiogenesis in obesity and in response to PPARγ activators through adipocyte VEGF and ANGPTL4 production

2008 ◽  
Vol 295 (5) ◽  
pp. E1056-E1064 ◽  
Author(s):  
Olga Gealekman ◽  
Alison Burkart ◽  
My Chouinard ◽  
Sarah M. Nicoloro ◽  
Juerg Straubhaar ◽  
...  

PPARγ activators such as rosiglitazone (RSG) stimulate adipocyte differentiation and increase subcutaneous adipose tissue mass. However, in addition to preadipocyte differentiation, adipose tissue expansion requires neovascularization to support increased adipocyte numbers. Paradoxically, endothelial cell growth and differentiation is potently inhibited by RSG in vitro, raising the question of how this drug can induce an increase in adipose tissue mass while inhibiting angiogenesis. We find that adipose tissue from mice treated with RSG have increased capillary density. To determine whether adipose tissue angiogenesis was stimulated by RSG, we developed a novel assay to study angiogenic sprout formation ex vivo. Angiogenic sprout formation from equally sized adipose tissue fragments, but not from aorta rings, was greatly increased by obesity and by TZD treatment in vivo. To define the mechanism involved in RSG-stimulated angiogenesis in adipose tissue, the expression of proangiogenic factors by adipocytes was examined. Expression of VEGFA and VEGFB, as well as of the angiopoietin-like factor-4 (ANGPTL4), was stimulated by in vivo treatment with RSG. To define the potential role of these factors, we analyzed their effects on endothelial cell growth and differentiation in vitro. We found that ANGPTL4 stimulates endothelial cell growth and tubule formation, albeit more weakly than VEGF. However, ANGPTL4 mitigates the growth inhibitory actions of RSG on endothelial cells in the presence or absence of VEGF. Thus, the interplay between VEGF and ANGPTL4 could lead to a net expansion of the adipose tissue capillary network, required for adipose tissue growth, in response to PPARγ activators.

1991 ◽  
Vol 11 (4) ◽  
pp. 2125-2132
Author(s):  
K Hagiwara ◽  
G Stenman ◽  
H Honda ◽  
P Sahlin ◽  
A Andersson ◽  
...  

Human platelet-derived endothelial cell growth factor (hPD-ECGF) is a novel angiogenic factor which stimulates endothelial cell growth in vitro and promotes angiogenesis in vivo. We report here the cloning and sequencing of the gene for hPD-ECGF and its flanking regions. This gene is composed of 10 exons dispersed over a 4.3-kb region. Its promoter lacks a TATA box and a CCAAT box, structures characteristic of eukaryotic promoters. Instead, six copies of potential Sp1-binding sites (GGGCGG or CCGCCC) were clustered just upstream of the transcription start sites. Southern blot analysis using genomic DNAs from several vertebrates suggested that the gene for PD-ECGF is conserved phylogenetically among vertebrates. The gene for hPD-ECGF was localized to chromosome 22 by analysis of a panel of human-rodent somatic cell hybrid lines.


2014 ◽  
Vol 127 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Sayaka Usui ◽  
Yoshitaka Iso ◽  
Masahiro Sasai ◽  
Takuya Mizukami ◽  
Hiroyoshi Mori ◽  
...  

Kisspeptin-10 suppressed endothelial cell growth in both in vivo and in vitro studies. The adverse effect of kisspeptin on endothelial cells was attributable, at least in part, to the induction of cellular senescence.


2007 ◽  
Vol 293 (6) ◽  
pp. E1482-E1491 ◽  
Author(s):  
Wei Cui ◽  
Sabina Paglialunga ◽  
David Kalant ◽  
HuiLing Lu ◽  
Christian Roy ◽  
...  

Acylation-stimulating protein (ASP), a lipogenic hormone, stimulates triglyceride (TG) synthesis and glucose transport upon activation of C5L2, a G protein-coupled receptor. ASP-deficient mice have reduced adipose tissue mass due to increased energy expenditure despite increased food intake. The objective of this study was to evaluate the blocking of ASP-C5L2 interaction via neutralizing antibodies (anti-ASP and anti-C5L2-L1 against C5L2 extracellular loop 1). In vitro, anti-ASP and anti-C5L2-L1 blocked ASP binding to C5L2 and efficiently inhibited ASP stimulation of TG synthesis and glucose transport. In vivo, neither anti-ASP nor anti-C5L2-L1 altered body weight, adipose tissue mass, food intake, or hormone levels (insulin, leptin, and adiponectin), but they did induce a significant delay in TG clearance [ P < 0.0001, 2-way repeated-measures (RM) ANOVA] and NEFA clearance ( P < 0.0001, 2-way RM ANOVA) after a fat load. After treatment with either anti-ASP or anti-C5L2-L1 antibody there was no change in adipose tissue AMPK activity, but neutralizing antibodies decreased perirenal TG mass (−38.4% anti-ASP, −18.8% anti-C5L2, P < 0.01–0.001) and perirenal LPL activity (−75.6% anti-ASP, −72.5% anti-C5L2, P < 0.05). In liver, anti-C5L2-L1 decreased TG mass (−42.8%, P < 0.05), whereas anti-ASP increased AMPK activity (+34.6%, P < 0.001). In the muscle, anti-C5L2-L1 significantly increased TG mass (+128.0%, P < 0.05), LPL activity (+226.1%, P < 0.001), and AMPK activity (+71.1%, P < 0.01). In addition, anti-ASP increased LPL activity (+164.4, P < 0.05) and AMPK activity (+53.9%, P < 0.05) in muscle. ASP/C5L2-neutralizing antibodies effectively block ASP-C5L2 interaction, altering lipid distribution and energy utilization.


1991 ◽  
Vol 11 (4) ◽  
pp. 2125-2132 ◽  
Author(s):  
K Hagiwara ◽  
G Stenman ◽  
H Honda ◽  
P Sahlin ◽  
A Andersson ◽  
...  

Human platelet-derived endothelial cell growth factor (hPD-ECGF) is a novel angiogenic factor which stimulates endothelial cell growth in vitro and promotes angiogenesis in vivo. We report here the cloning and sequencing of the gene for hPD-ECGF and its flanking regions. This gene is composed of 10 exons dispersed over a 4.3-kb region. Its promoter lacks a TATA box and a CCAAT box, structures characteristic of eukaryotic promoters. Instead, six copies of potential Sp1-binding sites (GGGCGG or CCGCCC) were clustered just upstream of the transcription start sites. Southern blot analysis using genomic DNAs from several vertebrates suggested that the gene for PD-ECGF is conserved phylogenetically among vertebrates. The gene for hPD-ECGF was localized to chromosome 22 by analysis of a panel of human-rodent somatic cell hybrid lines.


1994 ◽  
Vol 94 (5) ◽  
pp. 2036-2044 ◽  
Author(s):  
M Ziche ◽  
L Morbidelli ◽  
E Masini ◽  
S Amerini ◽  
H J Granger ◽  
...  

2009 ◽  
Vol 68 (4) ◽  
pp. 378-384 ◽  
Author(s):  
Henrike Sell ◽  
Jürgen Eckel

A strong causal link between increased adipose tissue mass and insulin resistance in tissues such as liver and skeletal muscle exists in obesity-related disorders such as type 2 diabetes. Increased adipose tissue mass in obese patients and patients with diabetes is associated with altered secretion of adipokines, which also includes chemotactic proteins. Adipose tissue releases a wide range of chemotactic proteins including many chemokines and chemerin, which are interesting targets for adipose tissue biology and for biomedical research in obesity and obesity-related diseases. This class of adipokines may be directly linked to a chronic state of low-grade inflammation and macrophage infiltration in adipose tissue, a concept intensively studied in adipose tissue biology in recent years. The inflammatory state of adipose tissue in obese patients may be the most important factor linking increased adipose tissue mass to insulin resistance. Furthermore, chemoattractant adipokines may play an important role in this situation, as many of these proteins possess biological activity beyond the recruitment of immune cells including effects on adipogenesis and glucose homeostasis in insulin-sensitive tissues. The present review provides a summary of experimental evidence of the role of adipose tissue-derived chemotactic cytokines and their function in insulin resistancein vivoandin vitro.


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