scholarly journals Free-amino acid metabolic profiling of visceral adipose tissue from obese subjects

Amino Acids ◽  
2020 ◽  
Vol 52 (8) ◽  
pp. 1125-1137
Author(s):  
M. C. Piro ◽  
M. Tesauro ◽  
A. M. Lena ◽  
P. Gentileschi ◽  
G. Sica ◽  
...  
Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Lenore R Rengel ◽  
Brittaney Obi ◽  
Jon Gould ◽  
Matthew Goldblatt ◽  
Andrew Kastenmeier ◽  
...  

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.


Author(s):  
Helen Sievert ◽  
Christin Krause ◽  
Cathleen Geißler ◽  
Martina Grohs ◽  
Alexander T. El-Gammal ◽  
...  

Abstract Objective The risk to develop type 2 diabetes increases with the amount of visceral adiposity presumably due to increased lipolysis and subsequent lipid accumulation in visceral organs. However, data describing the molecular regulation of these pathways in humans are rare. We tested if genes of the lipogenic and lipolytic pathways are associated with glucose intolerance independently of obesity in visceral adipose tissue (VAT) of obese subjects. Moreover, we studied DNA methylation of FASN (fatty acid synthase), that catalyses the synthesis of long-chain fatty acids, in VAT of the same subjects and whether it is associated with metabolic traits. Subjects and methods Visceral adipose tissue biopsies and blood samples were taken from 93 severely obese subjects undergoing bariatric surgery. Subjects were grouped in low HbA1c (L-HbA1c, HbA1c<6.5 %) and high HbA1c (H-HbA1c, HbA1c≥6.5 %) groups and expression of genes from the lipogenic and lipolytic pathways was analysed by TaqMan qPCR. DNA methylation of FASN was quantified by bisulfite-pyrosequencing. Results FASN expression was downregulated in visceral fat from subjects with high HbA1c (p = 0.00009). Expression of other lipogenetic (SCD, ELOVL6) or lipolytic genes (ADRB3, PNPLA2) and FABP4 was not changed. DNA methylation of FASN was increased at a regulatory ChoRE recognition site in the H-HbA1c-subgroup and correlated negatively with FASN mRNA (r = − 0.302, p = 0.0034) and positively with HbA1c (r = 0.296, p = 0.0040) and blood glucose (r = 0.363, p = 0.0005). Conclusions Epigenetic downregulation of FASN in visceral adipose tissue of obese subjects might contribute to limited de novo lipogenesis of important insulin sensitizing fatty acids and could thereby contribute to glucose intolerance and the development of type 2 diabetes independently of obesity.


2020 ◽  
Vol 21 (23) ◽  
pp. 9091
Author(s):  
Valentina Ceccarelli ◽  
Ilaria Barchetta ◽  
Flavia Agata Cimini ◽  
Laura Bertoccini ◽  
Caterina Chiappetta ◽  
...  

Biliverdin reductase A (BVR-A) is an enzyme involved in the regulation of insulin signalling. Knockout (KO) mice for hepatic BVR-A, on a high-fat diet, develop more severe glucose impairment and hepato-steatosis than the wild type, whereas loss of adipocyte BVR-A is associated with increased visceral adipose tissue (VAT) inflammation and adipocyte size. However, BVR-A expression in human VAT has not been investigated. We evaluated BVR-A mRNA expression levels by real-time PCR in the intra-operative omental biopsy of 38 obese subjects and investigated the association with metabolic impairment, VAT dysfunction, and biopsy-proven non-alcoholic fatty liver disease (NAFLD). Individuals with lower VAT BVR-A mRNA levels had significantly greater VAT IL-8 and Caspase 3 expression than those with higher BVR-A. Lower VAT BVR-A mRNA levels were associated with an increased adipocytes’ size. An association between lower VAT BVR-A expression and higher plasma gamma-glutamyl transpeptidase was also observed. Reduced VAT BVR-A was associated with NAFLD with an odds ratio of 1.38 (95% confidence interval: 1.02–1.9; χ2 test) and with AUROC = 0.89 (p = 0.002, 95% CI = 0.76–1.0). In conclusion, reduced BVR-A expression in omental adipose tissue is associated with VAT dysfunction and NAFLD, suggesting a possible involvement of BVR-A in the regulation of VAT homeostasis in presence of obesity.


2002 ◽  
Vol 58 (2) ◽  
pp. 101-107 ◽  
Author(s):  
Nobuyuki Miyatake ◽  
Hidetaka Nishikawa ◽  
Akie Morishita ◽  
Mie Kunitomi ◽  
Jun Wada ◽  
...  

2007 ◽  
Vol 293 (4) ◽  
pp. E958-E964 ◽  
Author(s):  
Gregory R. Steinberg ◽  
Bruce E. Kemp ◽  
Matthew J. Watt

We have investigated the gene and protein expression of adipose triglyceride lipase (ATGL) and triglyceride (TG) lipase activity from subcutaneous and visceral adipose tissue of lean and obese subjects. Visceral and subcutaneous adipose tissue was obtained from 16 age-matched lean and obese subjects during abdominal surgery. Tissues were analyzed for mRNA expression of lipolytic enzymes by real-time quantitative PCR. ATGL protein content was assessed by Western blot and TG lipase activity by radiometric assessment. Subcutaneous and visceral adipose tissue of obese subjects had elevated mRNA expression of PNPLA2 (ATGL) and other lipases including PNPLA3, PNPLA4, CES1, and LYPLAL1 ( P < 0.05). Surprisingly, ATGL protein expression and TG lipase activity were reduced in subcutaneous adipose tissue of obese subjects. Immunoprecipitation of ATGL reduced total TG lipase activity in adipose lysates by 70% in obese and 83% in lean subjects. No significant differences in the ATGL activator CGI-58 mRNA levels ( ABHD5) were associated with obesity. These data demonstrate that ATGL is important for efficient TG lipase activity in humans. They also demonstrate reduced ATGL protein expression and TG lipase activity despite increased mRNA expression of ATGL and other novel lipolytic enzymes in obesity. The lack of correlation between ATGL protein content and in vitro TG lipase activity indicates that small decrements in ATGL protein expression are not responsible for the reduction in TG lipase activity observed here in obesity, and that posttranslational modifications may be important.


2004 ◽  
Vol 219 (1-2) ◽  
pp. 9-15 ◽  
Author(s):  
Aina S Lihn ◽  
Jens M Bruun ◽  
Gengsheng He ◽  
Steen B Pedersen ◽  
Peter F Jensen ◽  
...  

2018 ◽  
Vol 243 (9) ◽  
pp. 786-795 ◽  
Author(s):  
Saimai Chatree ◽  
Chantacha Sitticharoon ◽  
Pailin Maikaew ◽  
Panapat Uawithya ◽  
Supornpim Chearskul

Neuropeptide Y is mainly expressed in the central nervous system to regulate food intake via its receptors, Y receptors, and in various peripheral tissues including adipose tissue. The objectives of this study were to compare Y5R mRNA and adipocyte parameters consisting of area, width, height, and perimeter either between obese and non-obese subjects or between subcutaneous and visceral fat as well as to compare between NPY, Y1R, Y2R, and Y5R mRNA expressions in subcutaneous and visceral adipose tissues. In subcutaneous and visceral adipose tissues, Y5R was greater in obese than in non-obese humans (both P < 0.05). Y1R mRNA expression was highest followed by Y5R, Y2R, and NPY mRNA expressions, respectively, in subcutaneous and visceral adipose tissues. Visceral Y5R mRNA had positive correlations with body weight, body mass index, waist circumference, hip circumference (R ≍ 0.4), and visceral Y1R mRNA (R = 0.773), but had a negative correlation with the quantitative insulin sensitivity check index (R=−0.421) (all P < 0.05). Subcutaneous and visceral adipocyte parameters were positively correlated with body weight, waist circumference, hip circumference, and waist-to-hip ratio, with greater values of correlation coefficient shown in visceral (R ≍ 0.5–0.8) than in subcutaneous adipocytes (R ≍ 0.4–0.6, all P < 0.05). The parameters of visceral adipocytes had positive correlations with serum NPY levels (R ≍ 0.4, all P < 0.05). Y5R mRNA in visceral adipose tissue is related to increased obesity and reduced insulin sensitivity. The dominant Y receptors in subcutaneous and visceral adipose tissue might be the Y1R and Y5R. Visceral adipocytes show higher correlations with obesity parameters than subcutaneous adipocytes, suggestive of an increased risk of metabolic syndrome in visceral obesity. Y1R and Y5R in visceral adipose tissue might be targets of drug development in prevention or treatment of adiposity. Impact statement Obesity, defined as excess fat accumulation, has been increasingly diagnosed worldwide causing adverse health consequences. The novel findings of this study were that Y5R mRNA expression in both subcutaneous and visceral fat was higher in obese than non-obese subjects. Furthermore, Y5R only in visceral fat, not subcutaneous fat, was positively correlated with visceral Y1R and obesity parameters but it was negatively correlated with the QUICKI. Moreover, we found that Y1R expression was highest followed by Y5R and Y2R, respectively, in both subcutaneous and visceral fat. Our results suggested that Y5R in visceral fat was associated with increased obesity and decreased insulin sensitivity. Y1R and Y5R might be the dominant receptors that mediate the effect of NPY-induced fat accumulation in both subcutaneous and visceral adipose tissues. Y1R and Y5R in visceral adipose tissue might be targets of drug development in prevention or treatment of obesity.


Sign in / Sign up

Export Citation Format

Share Document