Evaluation of the effects of quercetin and dihydroquercetin on cellular behavior and biomarkers of senescence in mesenchymal stem/stromal cells obtained from elderly patients

BACKGROUND: The accumulation of senescent cells in human tissues and organs leads to a decrease in the ability of tissues to renew and function normally, which affects the aging of the organism as a whole and contributes to the development of age-associated diseases. Selective elimination of senescent cells using senolytics may be a potential therapeutic approach in the prevention of such diseases. AIM: The main aim of this study was to investigate the effects of promising senolytics (quercetin and dihydroquercetin) on the behavior of senescent mesenchymal stem/stromal cells (sMSCs) obtained from elderly donors. METHODS: During the study of the effect of senolytics on sMSCs, tests assessing such characteristics and aspects of cell behavior as cell ageing markers, apoptosis, mitochondrial activity, and secretory activity were performed. We used the following research methods: light microscopy, fluorescence microscopy, real-time PCR with reverse transcription, timelapse, XTT test, ICC, and ELISA. RESULTS: In the heterogeneous population of primary isolated sMSCs obtained from elderly patients, cells with markers of cell aging (β-galactosidase, p21 expression, secretory senescence-associated phenotype (SASP)) prevail in comparison with the control. The addition of senolytics to sMSCs can contribute to the change of functional properties of these cells, including a decrease in the expression of p21 and production of SASP components. Based on IHC results for the cellular senescence marker p21, the mean elimination efficiency was 20.35% for quercetin and 57.36% for dihydroquercetin. Significant changes in SASP components (PAI-1, IL-6, MCP-1) in the conditioned medium of sMSCs were observed only with dihydroquercetin treatment. CONCLUSION: The results also demonstrate that quercetin induces statistically significant apoptosis in sMSCs compared to untreated controls, partially confirming its senolytic properties. In contrast, dihydroquercetin does not induce apoptosis and maintains cell viability. Thus, dihydroquercetin exhibits senomorphic properties — the ability to revert senescent cells to their original phenotype.