Experimental study on the regulation of oxidative stress in cardiomyocytes by polydopamine activated functional exosomes

YANG Zhe-hao; WANG Rong

doi:10.3969/j.issn.1672-5301.2025.02.013

Abstract：Objective To investigate the effect of polydopamine(PDA)on the production and activity of exosome(exo)secreted by bone marrow mesenchymal stem cells(BMSCs)and the regulation of cardiomyocyte(CM)oxidative stress by PDA-exo.Methods The BMSCs were characterised by flow cytometry.Nanoparticle tracking analysis(NTA)and scanning electron microscopy(SEM)were employed to characterise the PDA particles.The PDA-exo were characterised by Western blotting,transmission electron microscopy(TEM)and NTA following their isolation by ultracentrifugation.The impact of PDA-exo was validated through an in vitro simulation of an oxidative stress environment.The regulatory effect of cardiomyocytes(CM)and reactive oxygen species(ROS)was evaluated through the use of real-time quantitative fluorescence polymerase chain reaction(qRT-PCR),fluorescence microscopy,and fluorescence staining.The above experiments were completed in the laboratory of Cardiovascular Surgery of PLA General Hospital from June to November 2024,and the sample analysis was completed in the Academy of Military Medical Sciences of PLA.Results Bone marrow mesenchymal cells were stimulated by PDA nanoparticles,resulting in a 1.5-fold increase in the secretion of active exosomes.In comparison to the control group,PDA-exo demonstrated a notable reduction in the level of ROS in cardiomyocytes subjected to oxidative stress in vitro(P＜0.05).Additionally,there was a discernible increase in the expression of connexin 43(Cx43)and cardiac troponin T(c-TnT),accompanied by a reduction in the expression of apoptosis-related gene 3(caspase-3).The activity and function of cardiomyocytes were observed to be enhanced(P＜0.05).Conclusion PDA nanoparticles have been demonstrated to effectively stimulate bone marrow mesenchymal stem cells to secrete greater quantities of highly bioactive exosomes.Furthermore,PDA-exo have been shown to effectively remove ROS in cardiomyocytes,thereby restoring the activity and function of these cells.