Mitochondrial dysfunction plays an essential role in remodeling aging adipose tissue

Author(s):  
Ana Paula Azevêdo Macêdo ◽  
Adelino Sanchez Ramos da Silva ◽  
Vitor Rosetto Muñoz ◽  
Eduardo Rochete Ropelle ◽  
José Rodrigo Pauli
2021 ◽  
Vol 22 (6) ◽  
pp. 2881
Author(s):  
Clara Lefranc ◽  
Malou Friederich-Persson ◽  
Fabienne Foufelle ◽  
Aurélie Nguyen Dinh Cat ◽  
Frédéric Jaisser

Mineralocorticoid receptor (MR) expression is increased in the adipose tissue (AT) of obese patients and animals. We previously demonstrated that adipocyte-MR overexpression in mice (Adipo-MROE mice) is associated with metabolic alterations. Moreover, we showed that MR regulates mitochondrial dysfunction and cellular senescence in the visceral AT of obese db/db mice. Our hypothesis is that adipocyte-MR overactivation triggers mitochondrial dysfunction and cellular senescence, through increased mitochondrial oxidative stress (OS). Using the Adipo-MROE mice with conditional adipocyte-MR expression, we evaluated the specific effects of adipocyte-MR on global and mitochondrial OS, as well as on OS-induced damage. Mitochondrial function was assessed by high throughput respirometry. Molecular mechanisms were probed in AT focusing on mitochondrial quality control and senescence markers. Adipo-MROE mice exhibited increased mitochondrial OS and altered mitochondrial respiration, associated with reduced biogenesis and increased fission. This was associated with OS-induced DNA-damage and AT premature senescence. In conclusion, targeted adipocyte-MR overexpression leads to an imbalance in mitochondrial dynamics and regeneration, to mitochondrial dysfunction and to ageing in visceral AT. These data bring new insights into the MR-dependent AT dysfunction in obesity.


Cells ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 253 ◽  
Author(s):  
Yu-Sheng Chen ◽  
Hsuan-Miao Liu ◽  
Tzung-Yan Lee

Obesity has been shown to play a role in the pathogenesis of several forms of metabolic syndrome, including non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes. Ursodeoxycholic acid (UDCA) has been shown to possess antioxidant and anti-inflammatory properties and prevents mitochondrial dysfunction in the progression of obesity-associated diseases. The aim of the study was to evaluate the mechanisms of UDCA during obesity-linked hepatic mitochondrial dysfunction and obesity-associated adipose tissue macrophage-induced inflammation in obese mice. UDCA significantly decreased lipid droplets, reduced free fatty acids (FFA) and triglycerides (TG), improved mitochondrial function, and enhanced white adipose tissue browning in ob/ob mice. This is associated with increased hepatic energy expenditure, mitochondria biogenesis, and incorporation of bile acid metabolism (Abca1, Abcg1 mRNA and BSEP, FGFR4, and TGR5 protein). In addition, UDCA downregulated NF-κB and STAT3 phosphorylation by negative regulation of the expression of SOCS1 and SOCS3 signaling. These changes were accompanied by decreased angiogenesis, as shown by the downregulation of VEGF, VCAM, and TGF-βRII expression. Importantly, UDCA is equally effective in reducing whole body adiposity. This is associated with decreased adipose tissue expression of macrophage infiltration (CD11b, CD163, and CD206) and lipogenic capacity markers (lipofuscin, SREBP-1, and CD36). Furthermore, UDCA significantly upregulated adipose browning in association with upregulation of SIRT-1-PGC1-α signaling in epididymis adipose tissue (EWAT). These results suggest that multi-targeted therapies modulate glucose and lipid biosynthesis fluxes, inflammatory response, angiogenesis, and macrophage differentiation. Therefore, it may be suggested that UDCA treatment may be a novel therapeutic agent for obesity.


2014 ◽  
Vol 34 (1) ◽  
pp. 34-43 ◽  
Author(s):  
Erlie Jiang ◽  
Xiaoyuan Dai Perrard ◽  
Donglin Yang ◽  
Ilvira M. Khan ◽  
Jerry L. Perrard ◽  
...  

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Nicole Maddie ◽  
Maria Alicia A Carrillo-sepulveda

Endothelial dysfunction is a major complication of obesity and is an early contributor to hypertension. Perivascular adipose tissue (PVAT) surrounds most blood vessels and has different phenotypic properties based on its anatomical location. Thoracic aortic PVAT from humans and rodents is a brown-like adipose tissue and plays a vasculo-protective role under physiological conditions. In obesity, aortic PVAT expands, switches from a brown-like to a white-like phenotype and contributes to endothelial dysfunction. We hypothesized that loss of the brown-like phenotype of aortic PVAT in obesity is associated with mitochondrial dysfunction, resulting in PVAT and endothelial dysfunction. Eight-week-old female Wistar rats were randomized into two experimental groups: the Lean group (n=8) received a chow diet (5% fat, 48.7% carbohydrate [3.2% sucrose], 24.1% protein) and the Obese group (n=8) received a western diet (21% fat, 50% carbohydrate [34% sucrose], 20% protein), for 20 weeks. Increased body weight (340.57 vs. 265.37g leans, p<0.05) was confirmed in the obese group. At the experimental endpoint, thoracic aortas with intact (+PVAT) or removed PVAT (-PVAT) were obtained for analysis. Endothelial function was assessed in aortic rings +PVAT or -PVAT by performing concentration-response to acetylcholine using wire myography. The aortic ring (-PVAT) from the obese group exhibited impaired endothelium-dependent vasodilation (p<0.01). This effect was heightened in aortic rings (+PVAT) (p<0.05), showing a negative effect of PVAT on endothelial function during obesity. Mitochondrial dysfunction in PVAT from the obese group was characterized by decreased mitochondrial density (30% reduction, p<0.05), detected by quantification of Mitotracker fluorescence, and increased reactive oxygen species levels (4.34-fold increase, p<0.01), as evidenced by DHE staining. These effects were accompanied by decreased uncoupling protein-1 expression in the obese group (55% reduction, p<0.01). Moreover, Oil Red O staining showed larger lipid droplets in aortic PVAT from the obese group. Our results support that obesity-induced endothelial dysfunction is associated with a loss of the brown-like phenotype and mitochondrial dysfunction in PVAT.


Redox Biology ◽  
2021 ◽  
Vol 38 ◽  
pp. 101802
Author(s):  
Hayden W. Hyatt ◽  
Mustafa Ozdemir ◽  
Toshinori Yoshihara ◽  
Branden L. Nguyen ◽  
Rafael Deminice ◽  
...  

2020 ◽  
Vol 319 (6) ◽  
pp. E1053-E1060
Author(s):  
Logan K. Townsend ◽  
Henver S. Brunetta ◽  
Marcelo A. S. Mori

Obesity and insulin resistance (IR) are associated with endoplasmic reticulum (ER) stress and mitochondrial dysfunction in several tissues. Although for many years mitochondrial and ER function were studied separately, these organelles also connect to produce interdependent functions. Communication occurs at mitochondria-associated ER membranes (MAMs) and regulates lipid and calcium homeostasis, apoptosis, and the exchange of adenine nucleotides, among other things. Recent evidence suggests that MAMs contribute to organelle, cellular, and systemic metabolism. In obesity and IR models, metabolic tissues such as the liver, skeletal muscle, pancreas, and adipose tissue present alterations in MAM structure or function. The purpose of this mini review is to highlight the MAM disruptions that occur in each tissue during obesity and IR and its relationship with glucose homeostasis and IR. We also discuss the current controversy that surrounds MAMs’ role in the development of IR.


2017 ◽  
Vol 23 (10) ◽  
pp. S78
Author(s):  
Yoshikuni Obata ◽  
Takayuki Nakajima ◽  
Takashi Yokota ◽  
Ryosuke Shirakawa ◽  
Masaya Tsuda ◽  
...  

2011 ◽  
Vol 107 (2) ◽  
pp. 170-178 ◽  
Author(s):  
David Pajuelo ◽  
Helena Quesada ◽  
Sabina Díaz ◽  
Anabel Fernández-Iglesias ◽  
Anna Arola-Arnal ◽  
...  

The present study aims to determine the effects of grape seed proanthocyanidin extract (GSPE) on brown adipose tissue (BAT) mitochondrial function in a state of obesity induced by diet. Wistar male rats were fed with a cafeteria diet (Cd) for 4 months; during the last 21 d, two groups were treated with doses of 25 and 50 mg GSPE/kg body weight. In the BAT, enzymatic activities of citrate synthase, cytochrome c oxidase (COX) and ATPase were determined and gene expression was analysed by real-time PCR. The mitochondrial function of BAT was determined in fresh mitochondria by high-resolution respirometry using both pyruvate and carnitine–palmitoyl-CoA as substrates. The results show that the Cd causes an important decrease in the gene expression of sirtuin 1, nuclear respiratory factor 1, isocitrate dehydrogenase 3γ and COX5α and, what is more telling, decreases the levels of mitochondrial respiration both with pyruvate and canitine–palmitoyl-CoA. Most of these parameters, which are indicative of mitochondrial dysfunction due to diet-induced obesity, are improved by chronic supplementation of GSPE. The beneficial effects caused by the administration of GSPE are exhibited as a protection against weight gain, in spite of the Cd the rats were fed. These data indicate that chronic consumption of a moderate dose of GSPE can correct an energy imbalance in a situation of diet-induced obesity, thereby improving the mitochondrial function and thermogenic capacity of the BAT.


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