Extracellular vesicles (EVs) are spherical structures of cell membrane origin, ranging in the size from 40 nm to 5000 nm. They are involved in the horizontal transfer of many proteins and microRNAs. The mechanisms EV internalization include clathrin-dependent endocytosis, caveolin-dependent endocytosis, raft-mediated endocytosis, and macropinocytosis. Type 2 diabetes mellitus (T2DM) is a common group of metabolic disorders in adults; the incidence and prevalence increase in parallel with the obesity epidemic. Since adipose tissue plays a crucial role in the development of insulin resistance, EVs secreted by adipose tissue can be a kind of information transmitter in this process. EVs of adipocytic origin are predominantly absorbed by tissue macrophages, adipocytes themselves, hepatocytes, and skeletal muscles. This contributes to the M1 polarization of macrophages, a decrease in glucose uptake by hepatocytes and myocytes due to the transfer of functionally active microRNAs by these EVs, which affect carbohydrate and lipid metabolism. Patients with T2DM and impaired glucose tolerance have significantly higher levels of CD235a-positive (erythrocyte) EVs, as well as a tendency to increase CD68-positive (leukocyte) and CD62p-positive (platelets/endothelial cells) EVs. The levels of CD31+/CD146-positive BB (endothelial cells) were comparable between diabetic and euglycemic patients. EVs from diabetic patients were preferably internalized by monocytes (mainly classical and intermediate monocyte fractions and to a lesser extent by non-classical monocyte fractions) and B cells compared to euglycemic patients. Internalization of EVs from patients with T2DM by monocytes leads to decreased apoptosis, changes in differentiation, and suppression of reactions controlling oxidative stress in monocytes. Thus, insulin resistance increases secretion of EVs, which are preferentially internalized by monocytes and influence their function. EVs are considered as sources of promising clinical markers of insulin resistance, complications of diabetes mellitus (endothelial dysfunction, retinopathy, nephropathy, neuropathy), and markers of EVs can also be used to monitor the effectiveness of therapy for these complications.

Introduction. In most patients with colorectal cancer (CRC), the tumor develops against the background of metabolically healthy obesity or metabolic syndrome (more than 60 % of patients), the key pathogenetic moment of which is developing hyperinsulinemia. Metabolic changes are also characteristic of patients with colon polyps (CP), which are currently considered as the most significant precancerous diseases. It has been shown that fractions of small extracellular vesicles (EVs) of adipocyte origin are specifically enriched in extracellular matrix proteins, including matrix metalloproteinases (MMPs), chaperones, and some metabolic enzymes involved in the synthesis of lipids and carbohydrates. This was the reason for choosing exosomal markers in our study. Comparison of protein expression on CD9- and FABP-4 positive vesicles will be useful to explain some clinical issues, such as the effectiveness of thermoradiotherapy or radiotherapy in obese CRC patients; for a more substantiated search for vesicular prognostic markers in obese cancer patients. However, taking into account the lack of data in the literature on the level of MMPs and HSPs expression in the composition of the total pool of EVs and in the composition of FABP4-positive EVs in patients with PTC and CRC patients, the aim of the work was formulated.Aim. Study of the level of MMPs and heat shock proteins (HSPs) on CD9- and FABP4-positive EVs in patients with CP and CRC in relation to metabolic status.Materials and methods. The study included 12 patients with CRC (T2-4N0-2M0; mean age 59.6 ± 1.6 years) who were treated at the Department of Abdominal Oncology of the Cancer Research Institute of the Tomsk National Research Medical Center from 2019 to 2021. The comparison group included 10 patients with CP. The level of proteins on the surface of CD9- and FABP4-positive EVs was studied using flow cytometry.Results. MMP9-positive EVs were detected more often in CRC patients than in CP patients, however, MMP9+MMP2+TIMP-positive EVs were significantly more frequently detected in CP patients. Among the studied heat shock proteins, HSP60 was most often expressed on the surface of EVs, and HSP60-positive EVs were detected on the surface of CD9-positive exosomes in patients with PTC much more often than in CRC. In patients with CRC, compared with patients with СP, among FABP4-positive EVs, the proportion of triple-positive EVs and EVs with the MMP9+MMP2-TIMP1+ phenotype significantly increases, which in general may indicate overexpression of MMP9 and TIMP1 by adipocytes or marcrophages of adipose tissue in patients with CRC. Correlation analysis revealed multiple correlations of individual phenotypes of CD9-positive EVs in patients with CRC with body mass index and serum high density lipoprotein cholesterol levels, while the phenotypes of FABP4-positive EVs were associated mainly with triglyceride levels.Conclusions. The phenotypes of CD9-positive and FABP4-positive circulating EVs are promising as predictors for clarifying cancer risk in patients with colon polyps, as well as in terms of explaining the effectiveness of the treatment of CRC patients with obesity or metabolic syndrome.

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