EVALUATION OF THE LOCAL PROFILE OF CYTOKINES EXPRESSED BY NATIVE HEART VALVES OBTAINED FROM PATIENTS WITH ACQUIRED HEART DEFECTS

Doing. The pathogenesis of acquired heart defects is a complex process involving many different factors. One of the triggers for the development of dysfunctions of native heart valves can be an inflammatory process caused by various types of pathogens.

The aim of the study was to evaluate the local profile of cytokines expressed by native heart valves obtained from patients with acquired heart defects during cardiac surgery.

Materials and Methods: As a material for the study, biopsies of native mitral heart valves were obtained from 4 patients with infective endocarditis and from 10 patients with rheumatic heart disease. RNA was isolated using a commercial RNeasy® Plus Universal Mini Kit (Qiagen, Germany), protein extraction was performed using T-PER™ Tissue Protein Extraction Reagent lysis buffer (ThermoScientific, USA) with the addition of protease inhibitors Halt™ Protease Inhibitor Cocktail (ThermoScientific, USA) and 0.5M EDTA solution (ThermoScientific, USA). The level of cytokines expressed by native valves was determined by dot blotting using the Proteome Profiler™ Human Cytokine Array Kit (ARY005B) (R&D Systems, USA). Cytokine gene expression was assessed by qPCR using SYBR Green probes (JSC Evrogen, Russia) on a ViiA7 Real-Time PCR System amplifier (Applied Biosystems, USA). Statistical analysis of the results obtained was performed using the GraphPad Prism 8 program (GraphPad Software, USA).

Results: The proteins MIF (macrophage migration inhibitory factor), PAI-1 (plasminogen activator inhibitor-1), ICAM-1 (intercellular adhesion molecule-1) and CXCL12 (stromal growth factor-1) were found to be registered in native valves, obtained from both patients with IE and patients with RHD. Semi-quantitative analysis showed that native valves obtained from patients with IE are characterized by a four-fold increase in the level of PAI-1 secretion and a two-fold decrease in the level of ICAM-1 and CXCL12 compared with the control. MIF was expressed at the same level in both studied groups. IL-1ra (interleukin 1 receptor antagonist), IL-6 (interleukin 6), IL-8 (interleukin 8), IL-16 (interleukin 16), CCL4 (chemokine ligand 4), CCL5 (chemokine ligand 5), and CXCL1 ( chemokine ligand 1) were found only in valves affected by IE. The expression of the MIF, IL6, and IL8 genes was increased in the experimental group relative to the control, and the expression of the PAI1, IL1RA, and CXCL1– genes was decreased in the experiment relative to the control. The gene expression of ICAM1, CXCL12, CCL4, CCL5 and IL16 was the same in both studied groups.

Conclusions: The results of the study show that native heart valves affected by IE are characterized by a unique cytokine profile compared to valves obtained from patients with non-infectious endocardial pathology. Native heart valves affected by IE show nonspecific local inflammation, active neovascularization, and decreased resistance to pathogenic bacteremia.