Searchable abstracts of presentations at key conferences in endocrinology
Endocrine Abstracts (2016) 41 GP56 | DOI: 10.1530/endoabs.41.GP56

ECE2016 Guided Posters Cardiovascular endocrinology (9 abstracts)

The dual FXR/TGR5 agonist INT-767 reduces visceral fat mass, promoting preadipocyte brown differentiation, mitochondrial function and insulin sensitivity in a rabbit model of high fat diet-induced metabolic syndrome

Linda Vignozzi 1 , Ilaria Cellai 1 , Sandra Filippi 2 , Paolo Comeglio 1 , Tommaso Mello 3 , Daniele Bani 4 , Daniele Guasti 4 , Erica Sarchielli 4 , Annamaria Morelli 4 , Elena Maneschi 1 , Gabriella Barbara Vannelli 4 , Luciano Adorini 5 & Mario Maggi 1

1Sexual Medicine and Andrology Unit, Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy; 2Interdepartmental Laboratory of Functional and Cellular Pharmacology of Reproduction, Department of Neuroscience, Drug Research and Child Care, University of Florence, Florence, Italy; 3Gastroenterology Unit, Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy; 4Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; 5Intercept Pharmaceuticals, New York, New York, USA.

Expanding brown adipose tissue is a potential therapeutic strategy to counteract insulin resistance and metabolic syndrome (MetS). Farnesoid X receptor (FXR) and Takeda G protein-coupled receptor 5 (TGR5) activation enhances insulin sensitivity, suggesting the capacity of FXR/TGR5 agonists to promote brown differentiation in adipose tissue. Treatment with increasing doses of the dual FXR/TGR5 agonist INT-767 (3, 10, 30 mg/Kg bw, daily for 5 days a week, by oral gavage, for 12 weeks) in a rabbit model of high fat diet (HFD)-induced MetS, characterized by insulin resistance, hypertension, dyslipidemia,visceral adipose tissue (VAT) accumulation, dose-dependently reduced VAT mass, as well as glycemia, insulin resistance, cholesterol levels while significantly increasing HDL levels. INT-767 also reduced HFD-induced hepatomegaly and ALT increase. Treatment with INT-767 decreased HFD-induced adipocyte hypertrophy and reduced GLUT4 translocation to the plasma membrane, both considered hallmarks of insulin resistance in VAT. Treatment with INT-767 also induced VAT expression of genes related to nitric oxide (NO)/cGMP/protein kinase G (PKG) signaling, mediating both mitochondriogenesis and brown adipocyte differentiation. Rabbit preadipocytes (rPADs), isolated from the different groups, were then investigated for their spontaneous adipogenic potential. The expression of genes specific for: i) brown fat ii) mitochondrial biogenesis, iii) membrane respiratory chain, iv) pro-fusion and pro-fission proteins of mitochondria, were all significantly increased in rPADs from INT-767-treated compared to HFD rabbits. Transmission electron microscopy demonstrated that INT-767 treatment normalized HFD-induced reduction of mitochondrial cristae. INT-767 treatment was also able to: i) improve mitochondrial architecture and dynamic, with the majority of mitochondria continuously moving and changing shape, as assessed by time lapse imaging with mitochondria-targeted fluorescent probe MitoTracker, ii) reduce superoxide production, assessed by measuring the time-dependent accumulation of dihydroethidium-derived fluorescence, iii) improve insulin sensitivity. In conclusion, the dual FXR/TGR5 agonist INT-767 ameliorates the metabolic profile and reduces visceral adiposity by improving insulin sensitivity and promoting brown differentiation in visceral adipose tissue.

Article tools

My recent searches

No recent searches.