[Correlations between vessel stiffness and biomarkers of senescent cell in elderly patients].

Aim    To study the association between vascular wall stiffness and known markers for accumulation of senescent cells in blood, cells, and tissues of old patients.Material and methods    This study included male and female patients aged 65 years and older who were referred to an elective surgical intervention, that included a surgical incision in the area of the anterior abdominal wall or large joints and met the inclusion and exclusion criteria. For all patients, traditional cardiovascular (CV) risk factors and arterial wall stiffness (pulse wave velocity, PWV) were evaluated. Also, biomaterials (peripheral blood, skin, subcutaneous adipose tissue) were collected during the surgery and were used for isolation of several cell types and subsequent histological analysis to determine various markers of senescent cells.Results    The study included 80 patients aged 65 to 90 years. The correlation analysis identified the most significant indexes that reflected the accumulation of senescent cells at the systemic, tissue, and cellular levels (r>0.3, р<0.05) and showed positive and negative correlations with PWV. The following blood plasma factors were selected as the markers of ageing: insulin-like growth factor 1 (IGF-1), fibroblast growth factor 21 (FGF-21), and vascular endothelium adhesion molecule 1 (VCAM-1). A significant negative correlation between PWV and IGF-1 concentration was found. Among the tissue markers, P16INK, the key marker for tissue accumulation of senescent cells, predictably showed a positive correlation (r=0.394, p<0.05). A medium-strength correlation with parameters of the 96-h increment of mesenchymal stromal cells and fibroblasts and a weak correlation with IL-6 as a SASP (specific senescent-associated secretory phenotype) were noted. Results of the multifactorial linear regression analysis showed that the blood plasma marker, VCAM-1, and the cell marker, 96-h increment of fibroblasts, were associated with PWV regardless of the patient's age.Conclusion    Stiffness of great arteries as measured by PWV significantly correlates with a number of plasma, tissue, and cellular markers for accumulation of senescent cells. This fact suggests PWV as a candidate for inclusion in the panel of parameters for evaluation and monitoring of the biological age during the senolytic therapy.

Extracellular Matrix in the Regulation of Stem Cell Differentiation.

Extracellular matrix (ECM) proteins fill the space between cells in multicellular organisms, contributing to the structure of organs and tissues. The mechanical properties of ECM are well studied. At present, the role of individual ECM components and the three-dimensional tissue-specific matrices in the regulation of cell functional activity, proliferation, migration, acquisition of a specialized phenotype and its maintenance is intensively studied. In this review, we described main ECM structural proteins, enzymes, and extracellular vesicles and present the data on the participation of ECM components in the regulation of stem cell differentiation and self-maintenance, as well as approaches to the modeling of stem cells microenvironment using decellularized ECM.