The important role of the Wnt/β-catenin signaling pathway in small molecules mediated gingival mesenchymal stem cells transdifferentiate into neuron-like cells.

OBJECTIVE: Given their neural crest origin, gingival mesenchymal stem cells (GMSCs) possess high neurogenic potential, which makes them suitable for cell replacement therapy against neurodegenerative diseases. This study investigated whether GMSCs can be transdifferentiated into neurons in vitro using a protocol involving small molecules VCRFY (VPA, CHIR99021, Repsox, Forskolin, and Y-27632). The regulatory mechanisms of key signaling pathways were also investigated.

METHODS: Neuronal induction of GMSCs was conducted using a small molecules-based protocol over 7 days, which included the evaluation of cell morphology, proliferation, expressions of neurogenic markers, and intracellular calcium oscillation. The activation of canonical the Wnt signaling pathway was assessed by examining the protein content and subcellular localization of β-catenin.

RESULTS: Small molecules-treated GMSCs displayed neuronal morphology and increased expression of neurogenic markers, including class III beta-tubulin (TUJ1), neuron-specific enolase (NSE), microtube-associated protein 2 (MAP2), and neurofilament medium (NFM), verified through RT-qPCR, western blotting, and immunocytochemistry. Based on the results of Fluo-4 AM calcium flux assay, small molecules-treated GMSCs exhibited enhanced electrophysiological activity. GMSC proliferation halted after 2 days of treatment. Among the small molecules, CHIR99021 exhibited the highest neuronal induction efficiency. Furthermore, activation of the Wnt/β-catenin signaling pathway augmented neuronal differentiation.

CONCLUSIONS: Small molecule-based cellular reprogramming can efficiently generate neurons from GMSCs, with Wnt/β-catenin signaling to play a critical role in neuronal induction.