Human dental pulp stem cells grafted into C57BL/6J hippocampus differentiate towards immature neuronal like cells displaying action potential firing activity

Abstract

Stem cell therapy represents a promising strategy for the replacement and functional restoration of damaged neural tissue in neurodegenerative conditions. Human dental pulp stem cells (hDPSCs) have emerged as potential candidates for neuroregeneration due to their ease of isolation, neural crest origin, neurotrophic and anti-inflammatory capacity, and demonstrated ability to differentiate in vitro into neuronal-like cells exhibiting electrophysiological activity. Although the immunomodulatory and neuroprotective properties of hDPSCs have been reported in multiple models of brain disease, their capacity to functionally integrate into host neuronal circuits remain poorly understood. In this study, we have grafted green fluorescent protein (GFP)-transduced, neural preconditioned hDPSCs into the CA1 region of the hippocampus of C57BL/6J mice. One month after transplantation, GFP+-hDPSCs survived in the brains of non-immunosuppressed mice and remained localized within the grafted area. Notably, the transplanted cells underwent in situ differentiation and exhibited a neuroblast-like phenotype, characterized by positive doublecortin expression and immature neuronal-like electrophysiological properties, like high membrane input resistance, low capacitance, and the ability to generate single action potentials after stimulation. Together, these findings provide the first evidence that hDPSCs can survive and integrate into the hippocampal network of the mouse brain at one-month post graft, supporting their potential use for future therapeutic applications in acute brain lesions and neurodegenerative disorders.