Ethanol-induced alterations in mesenchymal stromal cells and the effects of aspalathin: implications for alcohol-associated osteonecrosis

Introduction Alcohol-associated osteonecrosis is a debilitating condition characterized by progressive bone destruction. Although mesenchymal stromal cells (MSCs) play a critical role in tissue repair, the effects of chronic alcohol exposure on MSCs and their responsiveness to microenvironmental signals remain unclear. Methods MSCs were exposed to ethanol (EtOH) to evaluate changes in viable cell number, ROS-related fluorescence signals, and the expression of mitochondrial-related, senescence-associated, and chemokine signaling-related molecules. CXCL12 expression was examined in human femoral head specimens and ethanol-exposed osteocyte-like cells. The effects of aspalathin (ASP) on EtOH-induced alterations in MSCs were also investigated. Results EtOH exposure reduced viable MSC number and increased ROS-related fluorescence signals. It was also associated with decreased expression of ATP5A and CXCR4 and increased expression of p16. CXCL12 expression was higher in alcohol-associated osteonecrosis tissue than in osteoarthritis tissue and appeared qualitatively increased in ethanol-exposed osteocyte-like cells. These findings indicate altered CXCL12 and CXCR4 expression across the tissue and in vitro experimental settings. ASP treatment attenuated the EtOH-induced reduction in the CCK-8 signal, was associated with attenuation of ROS-related fluorescence signals, significantly restored ATP5A expression, suppressed p16 expression, and showed a non-significant trend toward recovery of CXCR4 expression. Conclusions Ethanol exposure was associated with alterations in the cellular state of MSCs, accompanied by changes in ROS-related fluorescence signals and the expression of mitochondrial-related, senescence-associated, and chemokine signaling-related molecules. ASP partially attenuated some of these ethanol-induced alterations. Further studies are required to clarify the functional significance of these findings and to validate them in vivo.