Correlations between biomarkers of senescent cell accumulation at the systemic, tissue and cellular levels in elderly patients

The aim of the study was to investigate the relationship between established clinical systemic biomarkers of ageing and the development of age-associated diseases and senescent cell biomarkers at tissue and cellular levels. Thirty-eight patients (mean age 70 +/- 4.9 years) who were assessed for traditional risk factors for cardiovas-cular diseases were included. From all patients we obtained biomaterials (peripheral blood, skin, subcutaneous fatty tissue) and isolated different cell types (peripheral blood mononuclear cells (PBMC), fibroblasts (FB) and mesenchymal stem/stromal cells (MSC)). Isolated cells were analyzed using several senescent cells biomarkers such as telomere length and telomerase activity, proliferation rate, cell cycle inhibitor expression (p16 and p21), b-galactosidase activity, gH2AX expression. CD34+ cell content in peripheral blood was determined by flow cytometry. Systemic senescent cell-associated factors (insulin-like growth factor 1 (IGF-1), fibroblast growth factor 21 (FGF-21), osteoprogerin, ferritin, soluble vascular cell adhesion molecule (VCAM-1), intercellular adhesion molecule 1 (ICAM-1)) in peripheral blood as well as senescence-associated secretory phenotype (SASP) components in MSC and FB secretome were evaluated by ELISA. Skin and adipose tissue biopsy samples were analyzed histologically to assess senescent cell markers. A strong significant association of tissue p16 expression with age (r = 0.600, p < 0.001), pulse wave velocity (PWV) (r = 0.394, p = 0.015), vascular cell adhesion molecule (VCAM-1) content (r = 0.312, p = 0.006) in the systemic blood stream and p16 mRNA level in the blood mononuclear cells (MNCs) (r = 0.380, p = 0.046) were confirmed by correlation analysis. Statistically significant correlations were found with indicators of FBs and MSCs proliferation in culture and acquisition of SASP by the cells. Thus, p16 expression in tissues correlated significantly with interleukin-6 (IL-6) (r = 0.485, p < 0.05) and monocyte chemoattractant protein type 1 (MCP-1) (r = 0.372, p < 0.05) secretion by isolated cells. The results of regression analysis confirmed that, regardless of

Automated summary

The aim of this study was to explore the relationship between established clinical biomarkers of aging and the development of age-related diseases and senescent cell biomarkers at tissue and cellular levels. The findings confirmed a significant correlation between tissue p16 expression and age, pulse wave velocity, vascular cell adhesion molecule (VCAM-1) content in the systemic blood stream, as well as p16 mRNA level in blood mononuclear cells (MNCs). The proliferation indicators of fibroblasts (FBs) and mesenchymal stem/stromal cells (MSCs) in culture showed significant correlations with the acquisition of senescence-associated secretory phenotype (SASP) by the cells.