The role of visceral adipose tissue on improvement in insulin sensitivity following Roux-en-Y gastric bypass: a study in Chinese diabetic patients with mild and central obesity

Abstract Obesity and body fat distribution are important risk factors for the development of type 2 diabetes and metabolic syndrome. Evidence has accumulated that this risk is related to intrinsic differences in behavior of adipocytes in different fat depots. We recently identified LIM domain only 3 (LMO3) in human mature visceral adipocytes; however, its function in these cells is currently unknown. The aim of this study was to determine the potential involvement of LMO3-dependent pathways in the modulation of key functions of mature adipocytes during obesity. Based on a recently engineered hybrid rAAV serotype Rec2 shown to efficiently transduce both brown adipose tissue (BAT) and white adipose tissue (WAT), we delivered YFP or Lmo3 to epididymal WAT (eWAT) of C57Bl6/J mice on a high-fat diet (HFD). The effects of eWAT transduction on metabolic parameters were evaluated 10 weeks later. To further define the role of LMO3 in insulin-stimulated glucose uptake, insulin signaling, adipocyte bioenergetics, as well as endocrine function, experiments were conducted in 3T3-L1 adipocytes and newly differentiated human primary mature adipocytes, engineered for transient gain or loss of LMO3 expression, respectively. AAV transduction of eWAT results in strong and stable Lmo3 expression specifically in the adipocyte fraction over a course of 10 weeks with HFD feeding. LMO3 expression in eWAT significantly improved insulin sensitivity and healthy visceral adipose tissue expansion in diet-induced obesity, paralleled by increased serum adiponectin. In vitro, LMO3 expression in 3T3-L1 adipocytes increased PPARγ transcriptional activity, insulin-stimulated GLUT4 translocation and glucose uptake, as well as mitochondrial oxidative capacity in addition to fatty acid oxidation. Mechanistically, LMO3 induced the PPARγ coregulator Ncoa1, which was required for LMO3 to enhance glucose uptake and mitochondrial oxidative gene expression. In human mature adipocytes, LMO3 overexpression promoted, while silencing of LMO3 suppressed mitochondrial oxidative capacity. LMO3 expression in visceral adipose tissue regulates multiple genes that preserve adipose tissue functionality during obesity, such as glucose metabolism, insulin sensitivity, mitochondrial function, and adiponectin secretion. Together with increased PPARγ activity and Ncoa1 expression, these gene expression changes promote insulin-induced GLUT4 translocation, glucose uptake in addition to increased mitochondrial oxidative capacity, limiting HFD-induced adipose dysfunction. These data add LMO3 as a novel regulator improving visceral adipose tissue function during obesity. Key messages LMO3 increases beneficial visceral adipose tissue expansion and insulin sensitivity in vivo. LMO3 increases glucose uptake and oxidative mitochondrial activity in adipocytes. LMO3 increases nuclear coactivator 1 (Ncoa1). LMO3-enhanced glucose uptake and mitochondrial gene expression requires Ncoa1.

Download Full-text

Central Obesity and Visceral Adipose Tissue Are Not Associated With Incident Atherosclerotic Cardiovascular Disease Events in Older Men

Journal of the American Heart Association ◽

10.1161/jaha.118.009172 ◽

2018 ◽

Vol 7 (16) ◽

Cited By ~ 4

Author(s):

John T. Schousboe ◽

Allyson M. Kats ◽

Lisa Langsetmo ◽

Tien N. Vo ◽

Brent C. Taylor ◽

...

Keyword(s):

Cardiovascular Disease ◽

Adipose Tissue ◽

Visceral Adipose Tissue ◽

Central Obesity ◽

Older Men ◽

Atherosclerotic Cardiovascular Disease ◽

Visceral Adipose

Download Full-text

Protocatechuic acids protects against high glucose- induced insulin resistance in human visceral adipose tissue

Problems of Endocrinology ◽

10.14341/probl201662545-46 ◽

2016 ◽

Vol 62 (5) ◽

pp. 45-46

Author(s):

Paulina Ormazabal ◽

Beatrice Scazzocchio ◽

Rosaria Varì ◽

Annunziata Iacovelli ◽

Roberta Masella

Keyword(s):

Insulin Resistance ◽

Adipose Tissue ◽

Visceral Adipose Tissue ◽

High Glucose ◽

Protective Role ◽

Insulin Sensitizer ◽

20 Nm ◽

Visceral Adipose

Adipocytes exposed to high glucose concentrations exhibit impaired insulin signaling. Binding of insulin to its membrane receptor activates insulin metabolic pathway leading to IRS-1 and AKT phosphorylations. The accumulation of visceral adipose tissue (VAT) correlates with insulin resistance and metabolic syndrome. Anthocyanins (ACN) are bioactive food compounds of great nutritional interest. We have shown that protocatechuic acid (PCA), a major metabolite of ACN, might exert insulin-sensitizer activities in human visceral adipose tissue. The aim of this work was to define the protective role of PCA against insulin-resistance induced by high glucose in VAT.Methodology: VAT obtained from control subject (BMI≤25) were separated in four experimental groups: i) PCA: samples treated for 24 h with 100 μM PCA, ii) GLU: VAT treated with 30 mM glucose for 24 h, iii) PCA+GLU: 1 hour incubation with 100 μM PCA before adding glucose (30 mM, 24 h), iv) CTR: vehicle. After treatment, VAT groups were (or not) acutely stimulated with insulin (20 nM, 20 min). Tyr-IRS-1 and Ser-Akt phosphorylations were assessed by Western blotting (WB) in basal or insulin stimulated tissues in all experimental groups. Samples were assessed for IRS-1, IR, Akt and GLUT4 protein content by WB. Results: No differences in protein contents between experimental groups were found. GLU tissues showed a lower increment in insulin-stimulated phosphorylation of IRS-1 and Akt compared to CTR and PCA samples. This impaired activation was completely reversed by the pretreatment with PCA.Conclusion: An in-vitro insulin-resistance condition induced by high glucose was established in biopsies of VAT. PCA restores the ability of GLU-tissues to fully respond to insulin by increasing IRS-1 and Akt phosphorylations. These results confirm the insulin-sensitizer effect of PCA on VAT previously reported by our group. An anthocyanin rich diet might help to protect against insulin-resistance in VAT.

Download Full-text

Abstract 14315: New Insights Into the Mechanisms of Sepsis: The Role of Proprotein Convertase Subtilisin/kexin Type 9 as a Key Regulator of Pathogen Toxin Clearance

Circulation ◽

10.1161/circ.132.suppl_3.14315 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Elena Topchiy ◽

Yingjin Wang ◽

John Boyd ◽

Keith R Walley

Keyword(s):

Adipose Tissue ◽

Visceral Adipose Tissue ◽

Ex Vivo ◽

Fluorescent Microscopy ◽

Hepatic Uptake ◽

Cardiovascular Complications ◽

Proprotein Convertase ◽

Bacterial Endotoxins ◽

Visceral Adipose

Background: To prevent severe inflammation during infection, the patient must quickly clear bacterial endotoxins from the circulation before they accumulate and are able to interact with immune cells and vascular endothelium, and induce inflammatory organ failure. Bacterial endotoxins are carried within lipoprotein particles. Thus, one mechanism of action for sepsis treatments could be acceleration of lipoprotein clearance by adipocytes and hepatocytes. Proprotein convertase subtilisin/kexin type 9 (PCSK9) decreases the rate of lipoprotein clearance. We have recently reported that reduced function of PCSK9 improves outcome and prevents cardiovascular complications associated with sepsis. Hypothesis: PCSK9 inhibits LDL associated LPS clearance through hepatic LDLR and VLDL associated LPS clearance through adipose VLDLR. Methods and Results: Using siRNA against the LDLR in HepG2 hepatocytes decreased uptake of fluorescently labeled LPS (fLPS) after 48 hours by 1.50±0.10 fold (n=3, p<0.05). Addition of recombinant PCSK9 in the absence of LDLR did not alter uptake of LPS. We confirmed that hepatic uptake of LPS is exclusively via the LDLR by fluorescent microscopy of ex vivo LPS treated primary hepatocytes isolated from LDLR -/- mice. To address the importance of the LDLR upon clearance of LPS from plasma, we injected fLPS into the portal vein of LDLR-/-, PCSK9-/- and wild type mice (WT). Compared to WT, LDLR-/- mice had 36±13% (n=9, p<0.001) increase in plasma LPS after 1 hour, whereas PCSK9-/- show a significant decrease (28±4%, n=9, p<0.001) in plasma LPS. LDLR-/-, but not PCSK9-/- mice showed 46±7% decrease (n=10, p<0.05) in hepatic uptake. On the other hand, compared to the WT PCSK9-/- mice had 200±35% (n=8, p<0.001) increase in LPS uptake by visceral adipose tissue whereas LDLR-/- had no effect compared to WT mice. To further investigate LPS uptake by adipose tissue we injected flLPS into the tail vein of VLDLR-/- and WT mice. VLDLR-/- mice had 33±6% (n=10, p<0.001) decrease in visceral adipose tissue uptake, with no significant change in hepatic uptake. Conclusions: Expression of hepatic LDLR and adipose VLDLR is mainly regulated by PCSK9 and both play important role in clearing LPS from circulation.

Download Full-text

Increased Circulating and Visceral Adipose Tissue Expression Levels of YKL-40 in Obesity-Associated Type 2 Diabetes Are Related to Inflammation: Impact of Conventional Weight Loss and Gastric Bypass

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2010-0994 ◽

2011 ◽

Vol 96 (1) ◽

pp. 200-209 ◽

Cited By ~ 45

Author(s):

Victoria Catalán ◽

Javier Gómez-Ambrosi ◽

Amaia Rodríguez ◽

Beatriz Ramírez ◽

Fernando Rotellar ◽

...

Keyword(s):

Type 2 Diabetes ◽

Weight Loss ◽

Gastric Bypass ◽

Adipose Tissue ◽

Visceral Adipose Tissue ◽

Tissue Expression ◽

Expression Levels ◽

Visceral Adipose

Download Full-text

Enhanced Inflammation without Impairment of Insulin Signaling in the Visceral Adipose Tissue of 5α-Dihydrotestosterone-Induced Animal Model of Polycystic Ovary Syndrome

Experimental and Clinical Endocrinology & Diabetes ◽

10.1055/s-0043-104531 ◽

2017 ◽

Vol 125 (08) ◽

pp. 522-529 ◽

Cited By ~ 2

Author(s):

Danijela Milutinović ◽

Marina Nikolić ◽

Nataša Veličković ◽

Ana Djordjevic ◽

Biljana Bursać ◽

...

Keyword(s):

Animal Model ◽

Adipose Tissue ◽

Insulin Sensitivity ◽

Polycystic Ovary Syndrome ◽

Abdominal Obesity ◽

Visceral Adipose Tissue ◽

Polycystic Ovary ◽

Low Grade ◽

Ovary Syndrome ◽

Visceral Adipose

AbstractPolycystic ovary syndrome is a heterogeneous endocrine and metabolic disorder associated with abdominal obesity, dyslipidemia and insulin resistance. Since abdominal obesity is characterized by low-grade inflammation, the aim of the study was to investigate whether visceral adipose tissue inflammation linked to abdominal obesity and dyslipidemia could lead to impaired insulin sensitivity in the animal model of polycystic ovary syndrome.Female Wistar rats were treated with nonaromatizable 5α-dihydrotestosterone pellets in order to induce reproductive and metabolic characteristics of polycystic ovary syndrome. Glucose, triglycerides, non-esterified fatty acids and insulin were determined in blood plasma. Visceral adipose tissue inflammation was evaluated by the nuclear factor kappa B intracellular distribution, macrophage migration inhibitory factor protein level, as well as TNFα, IL6 and IL1β mRNA levels. Insulin sensitivity was assessed by intraperitoneal glucose tolerance test and homeostasis model assessment index, and through analysis of insulin signaling pathway in the visceral adipose tissue.Dihydrotestosterone treatment led to increased body weight, abdominal obesity and elevated triglycerides and non-esterified fatty acids, which were accompanied by the activation of nuclear factor kappa B and increase in macrophage migration inhibitory factor, IL6 and IL1β levels in the visceral adipose tissue. In parallel, insulin sensitivity was affected in 5α-dihydrotestosterone-treated animals only at the systemic and not at the level of visceral adipose tissue.The results showed that abdominal obesity and dyslipidemia in the animal model of polycystic ovary syndrome were accompanied with low-grade inflammation in the visceral adipose tissue. However, these metabolic disturbances did not result in decreased tissue insulin sensitivity.

Download Full-text

Whole-body skeletal muscle mass is not related to glucose tolerance or insulin sensitivity in overweight and obese men and women

Applied Physiology Nutrition and Metabolism ◽

10.1139/h08-060 ◽

2008 ◽

Vol 33 (4) ◽

pp. 769-774 ◽

Cited By ~ 32

Author(s):

Jennifer L. Kuk ◽

Katherine Kilpatrick ◽

Lance E. Davidson ◽

Robert Hudson ◽

Robert Ross

Keyword(s):

Skeletal Muscle ◽

Adipose Tissue ◽

Insulin Sensitivity ◽

Glucose Tolerance ◽

Muscle Mass ◽

Visceral Adipose Tissue ◽

Skeletal Muscle Mass ◽

Whole Body ◽

Men And Women ◽

Visceral Adipose

The relationship between skeletal muscle mass, visceral adipose tissue, insulin sensitivity, and glucose tolerance was examined in 214 overweight or obese, but otherwise healthy, men (n = 98) and women (n = 116) who participated in various exercise and (or) weight-loss intervention studies. Subjects had a 75 g oral glucose tolerance test and (or) insulin sensitivity measures by a 3 h hyperinsulinemic–euglycemic clamp technique. Whole-body skeletal muscle mass and visceral adipose tissue were measured using a multi-slice magnetic resonance imaging protocol. Total body skeletal muscle mass was not associated with any measure of glucose metabolism in men or women (p > 0.10). These observations remained independent of age and total adiposity. Conversely, visceral adipose tissue was a significant predictor of various measures of glucose metabolism in both men and women with or without control for age and (or) total body fat (p < 0.05). Although skeletal muscle is a primary site for glucose uptake and deposition, these findings suggest that unlike visceral adipose tissue, whole-body skeletal muscle mass per se is not associated with either glucose tolerance or insulin sensitivity in overweight and obese men and women.

Download Full-text