Abstract 17023: Adipose Tissue Specific Temporal Deletion of Ager Induces Weight Loss in Diet Induced Obese Mice and Improves Glucose Homeostasis

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Robin Wilson ◽  
Lakshmi Arivazhagan ◽  
Henry Ruiz ◽  
Jay Pendse ◽  
Laura Frye ◽  
...  

Introduction: The incidence of obesity and its comorbidities is increasing at an alarming rate in US and around the globe. Our previous studies showed that the receptor for advanced glycation end products (RAGE) and its ligands contribute to the pathogenesis of obesity and insulin resistance (IR), as global Ager (gene encoding RAGE) and adipocyte-specific Ager- deleted mice fed a high fat diet (HFD) showed protection from weight gain and IR. However, the role of Ager deletion in mice with established obesity, switched to low fat diet has not been tested. We hypothesize that temporal adipocyte-specific deletion of Ager in obese mice could enhance weight loss and improves glucose homeostasis. Methods: Mice with conditional adipocyte-specific Ager deletion were generated by breeding Ager flox/flox mice with AdipoQ ERT2 Cre recombinase mice resulting in Ager flox/flox / AdipoQ ERT2 Cre (+) and Cre (-) animals. Mice were fed HFD (60% kcal/fat) for 20 weeks starting at 8 weeks of age to establish obesity and were then treated with tamoxifen (TAM) (75 mg/kg per day x 3 alternative days) to induce deletion of Ager . After 4 weeks of TAM treatment, mice were switched to standard chow for 7 weeks and body weight was monitored regularly. Fasting glucose, insulin and glucose tolerance was measured. Results: After 7 weeks of switching to standard chow following TAM, Cre (+) lost significantly more body weight whereas Cre (-) mice showed no significant weight loss over 7 weeks. Furthermore, Cre (+) mice exhibited significantly higher food intake, lower fasting glucose, lower epididymal and inguinal white adipose tissue weights, and improved glucose and insulin tolerance compared to Cre (-) mice. Conclusions: Temporal adipocyte-specific deletion of Ager in mice with established obesity promotes weight loss and improves glucose homeostasis. RAGE may act as a novel therapeutic target in obesity.

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Venkateswaran Subramanian ◽  
Anju Balakrishnan ◽  
Deborah A Howatt ◽  
Jessica J Moorleghen ◽  
Wendy S Katz

Background and Objective Obesity is associated with low-grade chronic inflammation and apoptosis that contributes to development of insulin resistance and other metabolic complications. Adipose tissue macrophages have been proposed as a link between obesity and insulin resistance. However, the mechanisms underlying these processes are not defined. Calpains are calcium-dependent neutral cysteine proteases that are essential for multiple cellular functions, such as cytoskeletal remodeling and apoptotic cell death. Recent studies have demonstrated that activated calpain promotes adipocyte differentiation in vitro, and enhances macrophage recruitment during nephropathy. However, the functional role of calpain activation in adipose tissue macrophage accumulation and obesity remains to be elucidated. The purpose of this study was to define whether pharmacological inhibition of calpain influences diet-induced obesity and adipose tissue macrophage accumulation in mice. Methods and Results Male C57BL/6 mice (8 weeks old; n=10 per group) were fed either low (10% kcal) or high (60% kcal) fat diet for 12 weeks. Calpeptin, a calpain inhibitor (2.5 mg/kg/day) or vehicle (DMSO) was administered daily by osmotic mini-pumps for 12 weeks. Calpeptin administration did not influence high fat diet induced body weight and fat mass gain throughout the study. Calpain inhibition had no effect on glucose and insulin tolerance in obese mice. However, calpain inhibition highly reduced adipocyte apoptosis, adipose tissue collagen and macrophage accumulation as evident by TUNEL, Picro Sirius and CD68 immunostaining. Real-time PCR analysis showed that calpain inhibition significantly suppressed inflammatory cytokines (TNFα, IL-6, MCP-1, F4/80) expression in adipose tissue (P<0.05 vs vehicle). In addition, Oil Red O staining revealed that calpain inhibition also suppressed accumulation of hepatic fat. Conclusion Pharmacological inhibition of calpain attenuated macrophage accumulation, adipocyte apoptosis, fibrosis and inflammation in diet-induced obese mice without influencing body weight gain and insulin tolerance.


Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 1965-P
Author(s):  
TEAYOUN KIM ◽  
JESSICA P. ANTIPENKO ◽  
SHELLY NASON ◽  
NATALIE PRESEDO ◽  
WILLIAM J. VAN DER POL ◽  
...  

2017 ◽  
Vol 313 (6) ◽  
pp. E731-E736 ◽  
Author(s):  
Wenjuan Wang ◽  
Xiangzhi Meng ◽  
Chun Yang ◽  
Dongliang Fang ◽  
Xuemeng Wang ◽  
...  

Loss of body weight and fat mass is one of the nonmotor symptoms of Parkinson’s disease (PD). Weight loss is due primarily to reduced energy intake and increased energy expenditure. Whereas inadequate energy intake in PD patients is caused mainly by appetite loss and impaired gastrointestinal absorption, the underlying mechanisms for increased energy expenditure remain largely unknown. Brown adipose tissue (BAT), a key thermogenic tissue in humans and other mammals, plays an important role in thermoregulation and energy metabolism; however, it has not been tested whether BAT is involved in the negative energy balance in PD. Here, using the 6-hydroxydopamine (6-OHDA) rat model of PD, we found that the activity of sympathetic nerve (SN), the expression of Ucp1 in BAT, and thermogenesis were increased in PD rats. BAT sympathetic denervation blocked sympathetic activity and decreased UCP1 expression in BAT and attenuated the loss of body weight in PD rats. Interestingly, sympathetic denervation of BAT was associated with decreased sympathetic tone and lipolysis in retroperitoneal and epididymal white adipose tissue. Our data suggeste that BAT-mediated thermogenesis may contribute to weight loss in PD.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Teayoun Kim ◽  
Shelly Nason ◽  
Jessica Antipenko ◽  
Natalie Presedo ◽  
Brian Finan ◽  
...  

2012 ◽  
Vol 32 (4) ◽  
pp. 733-741 ◽  
Author(s):  
Lílian Gonçalves Teixeira ◽  
Priscilla Ceci Lages ◽  
Tatianna Lemos Jascolka ◽  
Edenil Costa Aguilar ◽  
Fabíola Lacerda Pires Soares ◽  
...  

White tea is an unfermented tea made from young shoots of Camellia sinensis protected from sunlight to avoid polyphenol degradation. Although its levels of catechins are higher than those of green tea (derived from the same plant), there are no studies addressing the relationship between this tea and obesity associated with oxidative stress.The objective of this study was to evaluate the effect of white tea on obesity and its complications using a diet induced obesity model. Forty male C57BL/6 mice were fed a high-fat diet to induce obesity (Obese group) or the same diet supplemented with 0.5% white tea extract (Obese + WTE) for 8 weeks. Adipose tissue, serum lipid profile, and oxidative stress were studied. White tea supplementation was not able to reduce food intake, body weight, or visceral adiposity. Similarly, there were no changes in cholesterol rich lipoprotein profile between the groups. A reduction in blood triacylglycerols associated with increased cecal lipids was observed in the group fed the diet supplemented with white tea. White tea supplementation also reduced oxidative stress in liver and adipose tissue. In conclusion, white tea extract supplementation (0.5%) does not influence body weight or adiposity in obese mice. Its benefits are restricted to the reduction in oxidative stress associated with obesity and improvement of hypertriacylglycerolemia.


Author(s):  
Randall F. D'Souza ◽  
Stewart W.C. Masson ◽  
Jonathan S. T. Woodhead ◽  
Samuel L James ◽  
Caitlin MacRae ◽  
...  

Neutrophils accumulate in insulin sensitive tissues during obesity and may play a role in impairing insulin sensitivity. The major serine protease expressed by neutrophils is neutrophil elastase (NE), which is inhibited endogenously by α1-antitrypsin A (A1AT). We investigated the effect of exogenous (A1AT) treatment on diet induced metabolic dysfunction. Male C57Bl/6j mice fed a chow or a high fat diet (HFD) were randomized to receive 3x weekly i.p injections of either Prolastin (human A1AT; 2mg) or vehicle (PBS) for 10 weeks. Prolastin treatment did not affect plasma NE concentration, body weight, glucose tolerance or insulin sensitivity in chow fed mice. In contrast, Prolastin treatment attenuated HFD induced increases in plasma and white adipose tissue (WAT) NE without affecting circulatory neutrophil levels or increases in body weight. Prolastin-treated mice fed a HFD had improved insulin sensitivity, as assessed by insulin tolerance test, and this was associated with higher insulin-dependent IRS-1 (insulin receptor substrate) and AktSer473phosphorylation, and reduced inflammation markers in WAT but not liver or muscle. In 3T3-L1 adipocytes, Prolastin reversed recombinant NE-induced impairment of insulin-stimulated glucose uptake and IRS-1 phosphorylation. Furthermore, PDGF mediated p-AktSer473 activation and glucose uptake (which is independent of IRS-1) was not affected by recombinant NE treatment. Collectively, our findings suggest that NE infiltration of WAT during metabolic overload contributes to insulin-resistance by impairing insulin-induced IRS-1 signaling.


Author(s):  
Camille Marciniak ◽  
Oscar Chávez-Talavera ◽  
Robert Caiazzo ◽  
Thomas Hubert ◽  
Lorea Zubiaga ◽  
...  

Background/Objectives: The alimentary limb has been proposed to be a key driver of the weight-loss-independent metabolic improvements that occur upon bariatric surgery. However, the One Anastomosis Gastric Bypass (OAGB) procedure, consisting of one long biliary limb and a short common limb, induces stronger beneficial metabolic effects compared to Roux-en-Y Gastric Bypass (RYGB) in humans, despite the lack of an alimentary limb. The aim of this study was to assess the role of the biliary and common limbs in the weight-loss and metabolic effects that occur upon OAGB. Subjects/Methods: OAGB and sham surgery, with or without modifications of the length of either the biliary limb or the common limb, were performed in Gottingen-like minipigs. Weight loss, metabolic changes, and the effects on plasma and intestinal bile acids (BAs) were assessed 15 days after surgery. Results: OAGB significantly decreased body weight, improved glucose homeostasis, increased postprandial GLP-1 and fasting plasma BAs, and qualitatively changed the intestinal BA species composition. Resection of the biliary limb prevented the body weight loss effects of OAGB and attenuated the postprandial GLP-1 increase. Improvements in glucose homeostasis along with changes in plasma and intestinal BAs occurred after OAGB regardless of the biliary limb length. Resection of only the common limb reproduced the glucose homeostasis effects and the changes in intestinal BAs. Conclusions: Our results suggest that the changes in glucose metabolism and BAs after OAGB are mainly mediated by the length of the common limb, whereas the length of the biliary limb contributes to body weight loss.


Sign in / Sign up

Export Citation Format

Share Document