Adiponectin and its receptors in patients with cardiovascular disease

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Aim to determine the features of adiponectin expression, secretion of adiponectin and its receptors in local fat depots in CVD. Materials and methods The study included 90 patients with СAD (Group 1) and 60 patients with heart defects (Group 2). Adipocytes were isolated from samples of subcutaneous (SAT), epicardial (EAT) and perivascular (PVAT) adipose tissue obtained during CABG or heart valve replacement. The expression of adiponectin was determined by qPCR using TaqManTM Gene Expression Assays (Applied Biosystems, USA) in the ViiA 7 Real-Time PCR System (Applied Biosystems, USA), the levels of expression products was determined using enzyme immunoassay (Bender MedSystems GmbH, Vienna, Austria). The data were analyzed using the statistical software Statistica 9.0. Results EAT adipocytes were characterized by the lowest adiponectin expression relative to adipocytes of other localization both in Group 1 and Group 2. In patients Group 1 adiponectin expression in EAT was reduced relative in SAT and PVAT (by 1.2 and 1.5 times). In Group 2, the adiponectin mRNA in the EAT was lower than in the SAT and PVAT (1.4 and 1.5 times). The expression of adiponectin in EAT in Group 2 exceeded the same indicator in Group 1 by 1.2 times. The maximum expression of adiponectin was observed in the PVAT culture in patients of both groups. For Group 2, this indicator exceeded the values of Group 1 by 1.2 times. The content of adiponectin in the culture EAT was lower than in the SAT, both in Group 1 and Group 2 (by 1.3 and 1.13 times). The level of this indicator in Group 2 was 1.4 times higher than in Group 1. PVAT adipocytes of patients with CAD were characterized by the lowest level of adiponectin secretion in comparison with adipocytes of other localization. The adiponectin level in the PVAT of Group 2 exceeded that of fat stores of other localization and in Group 1 patients by 1.8 times. There were no statistically significant differences in the expression and concentration of adiponectin in the culture of adipocytes of the SAT between the groups of patients. In Group 1, the lowest level of AdipoR1 was found in the adipocyte culture of the PVAT. Noteworthy is the decrease in the level of AdipoR1 in Group 1 compared to the level of Group 2, observed in the SAT and PVAT: 1.3 and 1.5 times. There were no significant differences in the concentration of the AdipoR1 in the EAT, as well as AdipoR2 in all types of AT between the groups of patients. Conclusion: in CVD the EAT is characterized by minimal expression and secretion of adiponectin, regardless of nosology. In CAD despite the high level of expression of adiponectin, the adipocytes of the PVAT were found to have the lowest content in comparison with adipocytes of other localization. Dysregulation of the adiponectin/AdipoR axis is observed in PVAT, which may be due to low expression of adiponectin receptors and long-term processes of its post-translational modification and oligomerization in CAD.