The Thermogenic Capacity of Periaortic Adipose Tissue Is Reduced in Patients with Obesity

Presentation Number: LB SAT 76
Date of Presentation: April 1st, 2017

Diana Vargas1, Angelica Wintaco1, Carolina Lopez1, Edward Acero1, Jaime Camacho2, Marisol Carreno2, Juan Umaña2 and Fernando Lizcano*1
1Universidad de La Sabana, Chia, Colombia, 2Cardio-Infantil Foundation Cardiology Institute, Bogota, Colombia

Abstract

1Center of Biomedical Research from La Universidad de La Sabana-CIBUS

2Cardio-Infantil Foundation Cardiology Institute

Obesity induces cardiovascular risk and the phenotypic characteristics of adipose tissue in humans may vary according to their anatomical location. Several studies have shown that adipose tissue surrounding blood vessels may play an important role in cardiovascular physiology by releasing substances that regulate vascular and heart metabolism. However, it is unknown in humans if the fat surrounding the ascending aorta is energetically more active and its modulation could involve adverse metabolic events. In the present work, the molecular characteristics related to thermogenesis in samples of human periaortic adipose tissue (PAT) were evaluated comparing them with samples of subcutaneous adipose tissue (SAT) obtained from the sternotomy, in 23 patients submitted to revascularization or mitral valve replacement. Quantitative PCR analysis from tissue and expression of proteins obtained of the isolation of adipocyte precursor cells from the two sources were performed to determine the expression of genes and proteins involved in caloric expenditure. The results showed that, at the tissue level, RNA expression of UCP1 and PGC1a were significantly increased in PAT samples in relation to SAT. Besides, the levels of some adipoquines such as Adiponectin and FABP4 were decreased in PAT, while FGF21 showed significantly higher levels in PAT when compared with SAT. As for the expression of proteins obtained from adipocyte precursor cells, we found that PGC1a was increased in most PAT samples compared to SAT. Interestingly, when was analyzed the clinical conditions of the patients, it was found that the expression levels of TFAM, a mitochondrial protein, were significantly decreased in the PAT samples from overweight and obese patients. These data showed that PAT is an energetically more active tissue than SAT since the expression of thermogenic proteins like PGC1a were increased. On the other hand, thermogenesis properties of periaortic tissue can be reduced in overweight and obese Patients. These results increase the evidence that perivascular adipose tissue play a major role in cardiovascular diseases.

References: (1) Lim et al., 2013 Int J Cardiol. 169, 166-76. (2) Fitzgibbons et al., 2014 J Am Heart Assoc 3, e000582. (3) Tian et al., 2016 Cell Metab. 23, 165-78.

Nothing to Disclose: DV, AW, CL, EA, JC, MC, JU, FL

Sources of Research Support: Administrative Department, Colciencias (123065740713) and DIN Universidad de La Sabana Med 193-2015

 

Nothing to Disclose: DV, AW, CL, EA, JC, MC, JU, FL