Visualizing Age-Dependent Electrotaxis of Human Adipose-Derived Stem Cells Under Direct Current Electric Fields

Human adipose-derived stem cells (hADSCs) are pivotal for tissue regeneration and wound healing, and their directed migration is a prerequisite for exerting these therapeutic effects. Electric fields (EFs) are well-recognized as key cues guiding cell migration during wound repair, yet the electrotactic behavior of hADSCs -- especially how donor characteristics (e.g., age) regulate this behavior and its underlying molecular mechanisms -- remains poorly understood. This knowledge gap limits the optimized application of hADSCs in regenerative medicine. In this study, we first validated the existence of electrotaxis in hADSCs and confirmed its voltage dependence: under direct current electric fields (DCEFs) of 100-200 mV/mm, hADSCs migrated directionally toward the anode, with stronger EF intensities enhancing both migration directionality and speed (versus at 0 mV/mm control). We then compared hADSCs from young female donors (27.00 ± 4.58 years) and elderly female donors (62.33 ± 4.04 years) using RNA sequencing (RNA-seq) after 200 mV/mm DCEF stimulation. Transcriptomic analysis identified 747 upregulated and 624 downregulated genes in elderly hADSCs, with differentially expressed genes (DEGs) enriched in biological processes/pathways critical for electrotaxis -- including sodium ion transmembrane transport, voltage-gated sodium channel activity (GO terms), and the PI3K-Akt signaling pathway (KEGG pathway). Functionally, elderly hADSCs exhibited significantly reduced anodal migration (decreased accumulated distance, Euclidean distance, and directness) compared to young hADSCs under DCEF stimulation. This study provides the first evidence of age-dependent electrotaxis in hADSCs, demonstrating that donor age correlates with impaired electrotactic capacity. It further reveals that dysregulated sodium channel activity and PI3K-Akt signaling may underlie this age-related decline. These findings point to the potential regulatory mechanisms of hADSC electrotaxis and offer new insights for tailoring hADSC-based therapies (e.g., selecting optimal donors or targeting sodium/PI3K-Akt pathways) to improve tissue regeneration and wound healing outcomes.