Proteomic analysis of epicardial and subcutaneous adipose tissue reveals differences in proteins involved in oxidative stress

Abstract

Salgado-Somoza A, Teijeira-Fernández E, Fernández AL, González-Juanatey JR, Eiras S. Proteomic analysis of epicardial and subcutaneous adipose tissue reveals differences in proteins involved in oxidative stress. Am J Physiol Heart Circ Physiol 299: H202-H209, 2010. First published April 30, 2010; doi:10.1152/ajpheart.00120.2010.-Epicardial adipose tissue (EAT) is an endocrine organ adjacent to coronary arteries and myocardium without anatomy barriers. Locally produced adipokines may reflect or affect to cardiovascular physiology and pathology. Our aim was to study the protein expression profiles of EAT and subcutaneous adipose tissue (SAT) to identify local candidate molecules characterizing EAT in patients with cardiovascular disease. EAT and SAT samples were collected from 55 patients undergoing heart surgery. Proteins from these tissues were separated by two-dimensional (2D) gel electrophoresis, and differences between them were identified by MALDI-TOF/TOF spectra. Differences in protein levels were further investigated by real-time RT-PCR and Western blots, and production of reactive oxygen species (ROS) in EAT and SAT was evaluated by nitroblue tetrazolium chloride assays. ROS production was higher in EAT than SAT. We have found mRNA differences for catalase, glutathione S-transferase P, and protein disulfide isomerase, and 2D Western blots additionally showed post-translational differences for phosphoglycerate mutase 1; all four are related to oxidative stress pathways. EAT suffers greater oxidative stress than SAT in patients with cardiovascular diseases and exhibits associated proteomic differences that suggest the possibility of its association with myocardial stress in these patients. epicardial adipose tisssue OBESITY IS ONE OF THE MAIN causes of metabolic diseases. It is associated with a chronic inflammatory response and cardiovascular diseases (34). However, risk depends significantly on the distribution of adipose tissue in the body; for example, metabolic risk factors were more associated with omental adipose tissue (OAT) than with subcutaneous adipose tissue (SAT) among 3,001 participants in the Framingham Heart Study (6). These differences are plausibly due to different adipose tissues differing in adipokine expression and the production of inflammatory reactive oxygen species (ROS), which are known to be associated with cardiovascular disease (8); OAT is associated with more circulating substances related to inflammation and oxidative stress than SAT is (24).Epicardial adipose tissue (EAT) is a visceral fat pad adjacent to coronary arteries and the myocardium (11). The amount of EAT is related to left ventricle mass (13) and to the amount of intra-abdominal visceral fat, and visceral adiposity can in fact be evaluated by means of its echocardiographic measurement (10). Like other adipose tissues, EAT is now recognized as an endocrine organ, and its proximity to myocardium and coronary arteries suggests the possibility of paracrine action on these structures. In fact, in patients with coronary ...

Receptor for advanced glycation end-products expression in subcutaneous adipose tissue is related to coronary artery disease

“…Enhanced ROS production is an important factor associated with some cardiovascular diseases (20) such as CAD. Furthermore, we have previously observed that EAT presents higher oxidative stress than SAT (21).…”

Epicardial adipose tissue and relationship with coronary artery disease

“…The increase of proteins involved in the oxidative stress in EAT compared to that in SAT in patients with coronary artery disease suggests an association with increased myocardial oxidative stress in this category of patients [35].…”

Thermogenic potential and physiological relevance of human epicardial adipose tissue

“…2 In addition, higher oxidative stress levels, including reactive oxygen species production and higher levels of enzymes involved in regulating oxidative stress such as catalase and glutathione S-transferase P, have been reported in epicardial fat relative to subcutaneous fat in patients with CAD. 52 In addition to the studies looking at gene expression of the inflammatory and oxidative stress markers, proteomic and secretome analyses of epicardial fat obtained from CAD patients have also revealed that it is capable of secreting factors that can induce atherogenic changes in monocytes and endothelial cells, 53 as well as induce cardiomyocyte dysfunction. 54 Conditioned media derived from epicardial fat of guinea pigs was also reported to induce insulin resistance in rat cardiomyocytes.…”