Abstract 60: Perirenal Adipose Hypertrophy In A Congenic LH Rat: A Role For
            C17h6orf52

Central obesity, high blood pressure, dyslipidemia, and insulin resistance are a collection of cardiovascular and metabolic risk factors that form the basis of the Metabolic Syndrome (MetS) and represent a major public health burden worldwide. The phenotypes that define MetS are all highly heritable, but their genetic complexity necessitates the use of animal models to tease apart novel pathways. The Lyon Hypertensive (LH) rat is a well-characterized model of MetS, exhibiting profound differences in features of MetS compared to its metabolically healthy control, the Lyon Normotensive (LN) rat. To understand the genomic causes of MetS, we developed a congenic rat model, where a portion of LN chromosome 17 is introgressed on the LH genomic background. Male and female LH congenic (CON) rats and LH controls were phenotyped for a variety of MetS characteristics, including body growth and composition by nuclear magnetic resonance (NMR), metabolic rate (Promethion system), and adipose tissue collection and histological examination. There were significant decreases in body weight in the CON rats of both sexes compared to LH. We also found significant female-specific increases in body fat and decreases in metabolic rate. Tissue collection revealed the source of the increased adiposity in the female CON rats was specific to perirenal white adipose tissue (PWAT) and was further explained by significant hypertrophy in those adipocytes. Genome resequencing of the parental strains identified a gene, C17h6orf52 , as a strong contender underlying the phenotype differences in the congenics, with predicted amino acid changes and the loss of Nr2f2 transcription factor binding sites.

Download Full-text

The dual nature of obesity in metabolic programming: quantity versus quality of adipose tissue

Clinical Science ◽

10.1042/cs20201028 ◽

2020 ◽

Vol 134 (18) ◽

pp. 2447-2451

Author(s):

Anissa Viveiros ◽

Gavin Y. Oudit

Keyword(s):

Adipose Tissue ◽

Environmental Factors ◽

Maternal Obesity ◽

Metabolic Programming ◽

Dual Nature ◽

Prevalence Of Obesity ◽

Adipose Tissue Volume ◽

Males And Females ◽

Metabolically Healthy

Abstract The global prevalence of obesity has been rising at an alarming rate, accompanied by an increase in both childhood and maternal obesity. The concept of metabolic programming is highly topical, and in this context, describes a predisposition of offspring of obese mothers to the development of obesity independent of environmental factors. Research published in this issue of Clinical Science conducted by Litzenburger and colleagues (Clin. Sci. (Lond.) (2020) 134, 921–939) have identified sex-dependent differences in metabolic programming and identify putative signaling pathways involved in the differential phenotype of adipose tissue between males and females. Delineating the distinction between metabolically healthy and unhealthy obesity is a topic of emerging interest, and the precise nature of adipocytes are key to pathogenesis, independent of adipose tissue volume.

Download Full-text

Estimation of the in vivo metabolic rate of adipose tissue in obese mice

Aktuelle Ernährungsmedizin ◽

10.1055/s-2006-954529 ◽

2006 ◽

Vol 31 (05) ◽

Author(s):

S Keipert ◽

J Wessels ◽

M Klingenspor ◽

J Rozman

Keyword(s):

Adipose Tissue ◽

Metabolic Rate ◽

Obese Mice

Download Full-text

Muscle metabolome and adipose tissue mRNA expression of lipid metabolism-related genes in over-conditioned dairy cows differing in serum-metabotype

Scientific Reports ◽

10.1038/s41598-021-90577-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hassan Sadri ◽

Morteza Hosseini Ghaffari ◽

Katharina Schuh ◽

Christian Koch ◽

Helga Sauerwein

Keyword(s):

Adipose Tissue ◽

Dairy Cows ◽

Body Condition Score ◽

Subcutaneous Fat ◽

Oxidative Capacity ◽

Mrna Abundance ◽

Targeted Metabolomics ◽

Healthy Humans ◽

Condition Score ◽

Metabolically Healthy

AbstractOver-conditioned dairy cows, classified by body condition score (BCS) and backfat thickness (BFT) are less able to metabolically adapt to the rapidly increasing milk yield after parturition. Based on serum metabolome and cluster analyses, high BCS cows (HBCS) could be classified into metabotypes that are more similar to normal (NBCS) cows, i.e., HBCS predicted normal (HBCS-PN) than the HBCS predicted high (HBCS-PH) cows—similar to the concept of obese but metabolically healthy humans. Our objective was to compare muscle metabolome and mRNA abundance of genes related to lipogenesis and lipolysis in adipose tissue between HBCS-PH (n = 13), HBCS-PN (n = 6), and NBCS-PN (n = 15). Tail-head subcutaneous fat was biopsied on d −49, 3, 21, and 84 relative to parturition. Potential differences in the oxidative capacity of skeletal muscle were assessed by targeted metabolomics in M. semitendinosus from d 21. Besides characteristic changes with time, differences in the mRNA abundance were limited to lipogenesis-related genes on d −49 (HBCS-PH > HBCS-PN). The HBCS-PH had more than two-fold higher muscle concentrations of short (C2, C4-OH, C6-OH) and long-chain acylcarnitines (C16, C18, and C18:1) than HBCS-PN, indicating a greater oxidative capacity for fatty acids (and utilization of ketones) in muscle of HBCS-PN than HBCS-PH cows.

Download Full-text

Vitamin D signalling in adipose tissue

British Journal Of Nutrition ◽

10.1017/s0007114512003285 ◽

2012 ◽

Vol 108 (11) ◽

pp. 1915-1923 ◽

Cited By ~ 161

Author(s):

Cherlyn Ding ◽

Dan Gao ◽

John Wilding ◽

Paul Trayhurn ◽

Chen Bing

Keyword(s):

Vitamin D ◽

Adipose Tissue ◽

Vitamin D Deficiency ◽

Vitamin D Metabolites ◽

Hydroxyvitamin D ◽

The Metabolic Syndrome ◽

Prevalence Of Obesity ◽

Adipose Tissue Development ◽

And Function

Vitamin D deficiency and the rapid increase in the prevalence of obesity are both considered important public health issues. The classical role of vitamin D is in Ca homoeostasis and bone metabolism. Growing evidence suggests that the vitamin D system has a range of physiological functions, with vitamin D deficiency contributing to the pathogenesis of several major diseases, including obesity and the metabolic syndrome. Clinical studies have shown that obese individuals tend to have a low vitamin D status, which may link to the dysregulation of white adipose tissue. Recent studies suggest that adipose tissue may be a direct target of vitamin D. The expression of both the vitamin D receptor and 25-hydroxyvitamin D 1α-hydroxylase (CYP27B1) genes has been shown in murine and human adipocytes. There is evidence that vitamin D affects body fat mass by inhibiting adipogenic transcription factors and lipid accumulation during adipocyte differentiation. Some recent studies demonstrate that vitamin D metabolites also influence adipokine production and the inflammatory response in adipose tissue. Therefore, vitamin D deficiency may compromise the normal metabolic functioning of adipose tissue. Given the importance of the tissue in energy balance, lipid metabolism and inflammation in obesity, understanding the mechanisms of vitamin D action in adipocytes may have a significant impact on the maintenance of metabolic health. In the present review, we focus on the signalling role of vitamin D in adipocytes, particularly the potential mechanisms through which vitamin D may influence adipose tissue development and function.

Download Full-text

Abstract 3672: Loss of Perivascular Adipocyte Paracrine Function Leads to Increased Vascular Tone and Glucose Intolerance in Hypertension

Circulation ◽

10.1161/circ.118.suppl_18.s_463-b ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Kaivan Khavandi ◽

Adam Greenstein ◽

Sarah Withers ◽

Kazuhiko Sonoyama ◽

Sarah Lewis ◽

...

Keyword(s):

Oxidative Stress ◽

Metabolic Syndrome ◽

Adipose Tissue ◽

Vascular Tone ◽

Tnf Alpha ◽

Perivascular Adipose Tissue ◽

The Metabolic Syndrome ◽

Adipocyte Cell ◽

Therapeutic Opportunity

In order to investigate the contribution of perivascular adipose tissue (PVAT) to arterial function, a total of 55 small arteries harvested from 35 skin biopsies of patients with Metabolic Syndrome and matched controls were mounted as ring preparations in a wire myograph. Contractility to cumulative doses of Norepinephrine in the presence or absence of PVAT showed an anticontractile effect in arteries from healthy volunteers (p=0.009), which was lost in patients with Metabolic Syndrome. Bioassay studies confirmed that PVAT releases a hydrophilic anticontractile factor in health, which is absent in obesity. Using a soluble fragment of the human Type 1 receptor, we identified that the anticontractile factor was adiponectin, which is the sole mediator of vasodilation, acting by increasing endothelial bioavailability of nitric oxide. Significant endothelial dysfunction was observed in patients with Metabolic Syndrome (p<0.001). Quantitative image analysis of adipose tissue revealed significantly increased adipocyte cell size in patients with Metabolic Syndrome, compared with healthy controls (p<0.006). There was immunohistochemical evidence of inflammation with upregulation of TNF-alpha receptor 1 in these patients (p<0.001). Application of exogenous TNF-alpha abolished the anticontractile effect of PVAT by reducing adiponectin bioavailability. Oxidative stress also induced by cytokines TNF-alpha and IL-6 but not IL-1, reduced adiponectin production from PVAT and increased basal tone. When the obese microenvironment was replicated in vitro by inflicting hypoxia on PVAT, adiponectin activity was lost but then rescued by incubation with cytokine antagonists. Further application of the adiponectin receptor fragment abolished PVAT relaxation. We conclude that in healthy arteries, PVAT releases adiponectin which reduces vascular tone. In obesity, this is lost by a cascade of adipocyte hypertrophy, hypoxia, inflammation and oxidative stress. The resulting vasoconstriction contributes to hypertension, hypertriglyceridaemia and insulin resistance. Direct targeting of adiponectin release from PVAT therefore provides a novel therapeutic opportunity in the Metabolic Syndrome.

Download Full-text

Abstract 17843: Visceral Adipose Tissue Secretion of Adiponectin Decreases with Increased Body Mass Index

Circulation ◽

10.1161/circ.130.suppl_2.17843 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Lenore R Rengel ◽

Brittaney Obi ◽

Jon Gould ◽

Matthew Goldblatt ◽

Andrew Kastenmeier ◽

...

Keyword(s):

Adipose Tissue ◽

Visceral Adipose Tissue ◽

Metabolic Health ◽

Metabolically Healthy Obese ◽

Obese Subjects ◽

Healthy Obese ◽

Metabolically Healthy ◽

Visceral Adipose ◽

Subcutaneous Adipose

Introduction: Peripheral adiposity is associated with better metabolic health and higher plasma adiponectin (ADPN) levels. Since ADPN is secreted mainly by adipose tissue (AT), it is intriguing that higher visceral adipose tissue (VAT) is associated with lower ADPN levels and poor metabolic health. Hypothesis: We hypothesized that various AT depots differ in their ability to secrete ADPN. Methods: Paired AT samples (VAT and subcutaneous adipose tissue (SAT)) were collected from 19 subjects (10 women, 15 obese) undergoing elective abdominal surgery. The samples were cultured and the supernatant was collected after 24 hours. ADPN levels released into the supernatant from VAT and SAT were measured using multiplex methods. Subjects were defined as obese or non-obese (NO) based on BMI > or ≤ 30kg/m2 respectively. Obese subjects were further classified as metabolically unhealthy obese (MUO) or metabolically healthy obese (MHO) based on presence or absence of type 2 diabetes mellitus, hypertension, or cardiovascular disease at the time of surgery. Results: Mean ADPN secretion levels from SAT and VAT were similar in NO subjects (17.3 ± 3.4 vs. 9.8 ± 13.0 ng/mL/mg, p=0.5) whereas the mean ADPN secretion was lower from VAT among obese subjects (15.9 ± 0.8 vs. 4.5 ± 0.2 ng/mL/mg, p=0.0002). ADPN secretion decreased from VAT (r=-0.16) and increased from SAT (r=0.33) with increased BMI (Fig.1). When MHO and MUO were compared, ADPN secretion from VAT in MHO was reduced only slightly (16.1 ± 8.2 vs. 4.0 ± 2.0 ng/mL/mg, p=0.07) whereas ADPN secretion was significantly reduced in MUO (15.9 ± 5.3 vs. 4.7 ± 4.6 ng/mL/mg, p=0.003). Conclusions: Reduced ADPN secretion from VAT in subjects with increasing BMI may explain lower circulating ADPN levels in obese individuals. Higher ADPN production from SAT and the relatively preserved secretion of ADPN from VAT may explain metabolic health in some obese individuals. Futures studies will help identify factors that control ADPN secretion from AT.

Download Full-text