scholarly journals Loss of anti-contractile effect of perivascular adipose tissue in offspring of obese rats

2016 ◽  
Vol 40 (8) ◽  
pp. 1205-1214 ◽  
Author(s):  
K E Zaborska ◽  
M Wareing ◽  
G Edwards ◽  
C Austin

Abstract Rationale: Maternal obesity pre-programmes offspring to develop obesity and associated cardiovascular disease. Perivascular adipose tissue (PVAT) exerts an anti-contractile effect on the vasculature, which is reduced in hypertension and obesity. Objective: The objective of this study was to determine whether maternal obesity pre-programmes offspring to develop PVAT dysfunction in later life. Methods: Female Sprague–Dawley rats were fed a diet containing 10% (control) or 45% fat (high fat diet, HFD) for 12 weeks prior to mating and during pregnancy and lactation. Male offspring were killed at 12 or 24 weeks of age and tension in PVAT-intact or -denuded mesenteric artery segments was measured isometrically. Concentration–response curves were constructed to U46619 and norepinephrine. Results: Only 24-week-old HFD offspring were hypertensive (P<0.0001), although the anti-contractile effect of PVAT was lost in vessels from HFD offspring of each age. Inhibition of nitric oxide (NO) synthase with 100 μM l-NMMA attenuated the anti-contractile effect of PVAT and increased contractility of PVAT-denuded arteries (P<0.05, P<0.0001). The increase in contraction was smaller in PVAT-intact than PVAT-denuded vessels from 12-week-old HFD offspring, suggesting decreased PVAT-derived NO and release of a contractile factor (P<0.07). An additional, NO-independent effect of PVAT was evident only in norepinephrine-contracted vessels. Activation of AMP-activated kinase (with 10 μM A769662) was anti-contractile in PVAT-denuded (P<0.0001) and -intact (P<0.01) vessels and was due solely to NO in controls; the AMPK effect was similar in HFD offspring vessels (P<0.001 and P<0.01, respectively) but was partially NO-independent. Conclusions: The diminished anti-contractile effects of PVAT in offspring of HFD dams are primarily due to release of a PVAT-derived contractile factor and reduced NO bioavailability.

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Cristian Javier Rendon Mora ◽  
Emma D Flood ◽  
Stephanie W Watts ◽  
G.Andres Contreras ◽  
Janice Thompson

In adipogenesis, perivascular adipose tissue (PVAT) preadipocytes turn into adipocytes. In non-PVAT preadipocytes, mechanical forces affect the commitment and lipogenic stages of adipogenesis. The mechanism may involve PIEZO1, a mechanosensor, that boosts differentiation of progenitor cells towards osteogenic and fibroblastic lineages. Since hypertension causes changes in the vascular forces that could affect adipogenesis in PVAT, our objective was to evaluate PIEZO1 expression patterns in PVAT and the effects of PIEZO1 activation on the adipogenic potential of preadipocytes. We hypothesize that PIEZO1 activation limits the adipogenic potential of PVAT preadipocytes. PVAT from the thoracic aorta (APVAT) was collected from male Sprague Dawley rats at 10 weeks of age (n=5). Preadipocytes were obtained by Liberase digestion followed by serial passage of adherent cells. Preadipocyte progenitors, CD34+PDGFRα+, were harvested by magnetic-activated sorting. PIEZO1 expression was assessed by RT-qPCR and immunofluorescence (IF). Preadipocytes were induced to differentiate for 14 d in standard media (CON) or in the presence of PIEZO1 agonist Yoda (10μM) and inhibitor Dooku (5μM) during days 0-2 (commitment), 3-14 (lipogenesis), and 0-14 (overall adipogenesis). Adipogenesis was evaluated with IncuCyte Live-Cell system using the triglyceride stain Bodipy 493503. Triglyceride content is reported as Bodipy Intensity/Adipocyte Count. Piezo1 RNA was expressed in adipocytes and the stromal vascular fraction of APVAT. PIEZO1 IF signal was detected in SVF and preadipocyte. Triglyceride was reduced by Yoda (62 ± 14.3) and Dooku (49.3 ± 14) during 0-2 d compared to CON (312.5 ± 165.6). Neither Yoda nor Dooku for 12 d affected triglyceride accumulation compared to CON. In contrast, the lipid content of Yoda (77.7 ± 21.3) and Dooku (48.9 ± 15.2) treated cells during 14 d was reduced vs CON (312.5 ± 165.6). The expression of PIEZO1 in all PVAT fractions suggests mechanosensitivity. PIEZO1 activation during adipogenesis commitment impaired adipocyte maturation. These data provide evidence for the capacity of mechanosensory expressed in PVAT preadipocytes to modulate adipogenesis, underpinning the deleterious impact of hypertension on PVAT function.


2021 ◽  
Vol 30 (2) ◽  
pp. 205-212
Author(s):  
Erling Guo ◽  
Jin-Hwan Yoon ◽  
Wooyeon Jo ◽  
Jaeho Jin ◽  
Sang Ki Lee

PURPOSE: Perivascular adipose tissue (PVAT) is a type of adipose tissue that surrounds vessels to provide anti-contractile effects. This study aimed to investigate the effect of resistance training on NADPH oxidase, adiponectin, and endothelial NOS (eNOS) expression in the abdominal aorta and PVAT of ovariectomized rats.METHODS: Sprague-Dawley rats at 20 weeks of age were divided into three groups: sham control (Sham, n=10), OVX-control (OVX_ Con, n=10), and OVX-resistance exercise (OVX_Rex, n=10). Resistance training was performed by climbing a ladder for 12 weeks. Western blotting was used to analyze target protein expression in the rat abdominal aorta and PVAT.RESULTS: NADPH oxidase (p67phox) expression was significantly higher in the OVX_Con group than in the sham group, but it was significantly decreased in the OVX_Rex group. The expression of adiponectin, AKT, and eNOS in both abdominal aorta and PVAT was significantly reduced in the OVX_Con group than in the Sham group, but it was improved in the OVX_Rex group.CONCLUSIONS:The results suggest that regular resistance training inhibits p67phox and increases adiponectin expression and phosphorylation of AKT and eNOS in abdominal aortic PVAT of ovariectomized rats.


Author(s):  
Sophie N Saxton ◽  
Lauren K Toms ◽  
Robert G Aldous ◽  
Sarah B Withers ◽  
Jacqueline Ohanian ◽  
...  

AbstractPurposePerivascular adipose tissue (PVAT) exerts an anti-contractile effect which is vital in regulating vascular tone. This effect is mediated via sympathetic nervous stimulation of PVAT by a mechanism which involves noradrenaline uptake through organic cation transporter 3 (OCT3) and β3-adrenoceptor-mediated adiponectin release. In obesity, autonomic dysfunction occurs, which may result in a loss of PVAT function and subsequent vascular disease. Accordingly, we have investigated abnormalities in obese PVAT, and the potential for exercise in restoring function.MethodsVascular contractility to electrical field stimulation (EFS) was assessed ex vivo in the presence of pharmacological tools in ±PVAT vessels from obese and exercised obese mice. Immunohistochemistry was used to detect changes in expression of β3-adrenoceptors, OCT3 and tumour necrosis factor-α (TNFα) in PVAT.ResultsHigh fat feeding induced hypertension, hyperglycaemia, and hyperinsulinaemia, which was reversed using exercise, independent of weight loss. Obesity induced a loss of the PVAT anti-contractile effect, which could not be restored via β3-adrenoceptor activation. Moreover, adiponectin no longer exerts vasodilation. Additionally, exercise reversed PVAT dysfunction in obesity by reducing inflammation of PVAT and increasing β3-adrenoceptor and OCT3 expression, which were downregulated in obesity. Furthermore, the vasodilator effects of adiponectin were restored.ConclusionLoss of neutrally mediated PVAT anti-contractile function in obesity will contribute to the development of hypertension and type II diabetes. Exercise training will restore function and treat the vascular complications of obesity.


2021 ◽  
Vol 22 (5) ◽  
pp. 2649
Author(s):  
Alexis N. Orr ◽  
Janice M. Thompson ◽  
Janae M. Lyttle ◽  
Stephanie W. Watts

Transglutaminases (TGs) are crosslinking enzymes best known for their vascular remodeling in hypertension. They require calcium to form an isopeptide bond, connecting a glutamine to a protein bound lysine residue or a free amine donor such as norepinephrine (NE) or serotonin (5-HT). We discovered that perivascular adipose tissue (PVAT) contains significant amounts of these amines, making PVAT an ideal model to test interactions of amines and TGs. We hypothesized that transglutaminases are active in PVAT. Real time RT-PCR determined that Sprague Dawley rat aortic, superior mesenteric artery (SMA), and mesenteric resistance vessel (MR) PVATs express TG2 and blood coagulation Factor-XIII (FXIII) mRNA. Consistent with this, immunohistochemical analyses support that these PVATs all express TG2 and FXIII protein. The activity of TG2 and FXIII was investigated in tissue sections using substrate peptides that label active TGs when in a catalyzing calcium solution. Both TG2 and FXIII were active in rat aortic PVAT, SMAPVAT, and MRPVAT. Western blot analysis determined that the known TG inhibitor cystamine reduced incorporation of experimentally added amine donor 5-(biotinamido)pentylamine (BAP) into MRPVAT. Finally, experimentally added NE competitively inhibited incorporation of BAP into MRPVAT adipocytes. Further studies to determine the identity of amidated proteins will give insight into how these enzymes contribute to functions of PVAT and, ultimately, blood pressure.


2007 ◽  
Vol 292 (1) ◽  
pp. H245-H250 ◽  
Author(s):  
Zheng F. Ba ◽  
Ailing Lu ◽  
Tomoharu Shimizu ◽  
László Szalay ◽  
Martin G. Schwacha ◽  
...  

Although endothelin-1 (ET-1) induces vasoconstriction, it remains unknown whether 17β-estradiol (E2) treatment following trauma-hemorrhage alters these ET-1-induced vasoconstrictive effects. In addition, the role of the specific estrogen receptor (ER) subtypes (ER-α and ER-β) and the endothelium-localized downstream mechanisms of actions of E2 remain unclear. We hypothesized that E2 attenuates increased ET-1-induced vasoconstriction following trauma-hemorrhage via an ER-β-mediated pathway. To study this, aortic rings were isolated from male Sprague-Dawley rats following trauma-hemorrhage with or without E2 treatment, and alterations in tension were determined in vitro. Dose-response curves to ET-1 were determined, and the vasoactive properties of E2, propylpyrazole triol (PPT, ER-α agonist), and diarylpropionitrile (DPN, ER-β agonist) were determined. The results showed that trauma-hemorrhage significantly increased ET-1-induced vasoconstriction; however, administration of E2 normalized ET-1-induced vasoconstriction in trauma-hemorrhage vessels to the sham-operated control level. The ER-β agonist DPN counteracted ET-1-induced vasoconstriction, whereas the ER-α agonist PPT was ineffective. Moreover, the vasorelaxing effects of E2 were not observed in endothelium-denuded aortic rings or by pretreatment of the rings with a nitric oxide (NO) synthase inhibitor. Cyclooxygenase inhibition with indomethacin had no effect on the action of E2. Thus, E2 administration attenuates ET-1-induced vasoconstriction following trauma-hemorrhage via an ER-β-mediated pathway that is dependent on endothelium-derived NO synthesis.


Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1460 ◽  
Author(s):  
Yanqi Zhang ◽  
Kristi M. Crowe-White ◽  
Lingyan Kong ◽  
Libo Tan

The circulating level of vitamin A (VA; retinol) was reported to be lower in obese adults. It is unknown if maternal obesity influences the VA status of offspring. The objective of the study was to determine the VA status and deposition of neonatal and weanling rats reared by mothers consuming a normal or high-fat diet (NFD or HFD) with or without supplemented VA. Pregnant Sprague-Dawley rats were randomized to an NFD or HFD with 2.6 mg/kg VA. Upon delivery, half of the rat mothers in the NFD or HFD cohort were switched to an NFD or HFD with supplemented VA at 129 mg/kg (NFD+VA and HFD+VA group). The other half remained on their original diet (NFD and HFD group). At postnatal day 14 (P14), P25, and P35, pups (n = 4 or 3/group/time) were euthanized. The total retinol concentration in the serum, liver, visceral white adipose tissue (WAT), and brown adipose tissue (BAT) was measured. At P14, the HFD+VA group showed a significantly lower serum VA than the NFD+VA group. At P25, both the VA concentration and total mass in the liver, WAT, and BAT were significantly higher in the HFD+VA than the NFD+VA group. At P35, the HFD group exhibited a significantly higher VA concentration and mass in the liver and BAT compared with the NFD group. In conclusion, maternal HFD consumption resulted in more VA accumulation in storage organs in neonatal and/or weanling rats, which potentially compromised the availability of VA in circulation, especially under the VA-supplemented condition.


1989 ◽  
Vol 257 (4) ◽  
pp. E547-E553 ◽  
Author(s):  
A. Geloen ◽  
P. E. Roy ◽  
L. J. Bukowiecki

The effects of long-term diabetes (4 wk) on the development of parametrial (PWAT) and retroperitoneal (RWAT) white adipose tissues were studied in young Sprague-Dawley rats (170-200 g) injected with a single dose of streptozotocin (75 mg/kg). Diabetes stopped animal growth and totally abolished the normal increases in the wet weight, total protein content, and cellularity (estimated by DNA content) of PWAT and RWAT. Remarkably, the prolonged lack of insulin induced a progressive decrease of the cellularity of RWAT to levels that were lower than those of the initial controls. It also resulted in a marked reduction of adipocyte size. The tiny adipocytes seen in diabetic animals were characterized by the presence of multilocular triglyceride droplets. In general, the decreases in cell number, cell size, and protein content were more pronounced in RWAT than in PWAT. Quantitative cellular frequency studies revealed that adipocytes, and possibly also endothelial cells, contribute to the decrease in RWAT cellularity. The results demonstrate that 1) diabetes inhibits proliferative activity in adipose tissue, 2) total cell number reduction may occur in adipose depot of young growing rats, 3) this effect is depot dependent, and 4) the turnover of adipocytes and endothelial cells is relatively slow (several weeks).


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