Selegiline pre-induction modulates valproic acid effects on NGF expression during neuronal-like differentiation of rat bone marrow mesenchymal stem cells in vitro

Introduction: Neurodegenerative diseases are characterized by progressive neuronal loss and synaptic dysfunction. Neurotrophic factors such as nerve growth factor (NGF) is key molecular components linked to neuronal survival and functional connectivity. Mesenchymal stem cells derived from bone marrow (BMSCs) are promising candidates for regenerative approaches due to their differentiation capacity and neurotrophic paracrine effects. Valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, may epigenetically modulate gene expression and promote neurogenic programs. Selegiline, a selective MAO-B inhibitor with neuroprotective properties, may prime neurotrophic pathways.

Methods: Male rat bone marrow mesenchymal stem cells (rBMSCs) were expanded in culture. Cells were allocated to four groups (n=3 biological replicates/group): Control, Selegiline (20 μM, 24 h), VPA (6 μM, 48 h), and Selegiline pre-induction (20 μM, 24 h) followed by VPA (6 μM, 48 h). Neuronal-like morphology was qualitatively assessed by phase-contrast microscopy. Total RNA was extracted and RT-qPCR was performed using GAPDH as the reference gene. NGF relative expression was calculated using the 2^-ΔΔCt method.

Results: All treated groups exhibited neuronal-like morphological changes compared with fibroblast-like controls, with the most prominent neurite-like extensions and interconnected networks in the sequential Selegiline+VPA group. NGF expression showed a treatment-dependent pattern. Statistical analysis indicated a significant difference between VPA and Selegiline+VPA (p<0.01).

Conclusion: Selegiline pre-induction followed by VPA supports a more favorable neurotrophic profile in rBMSCs, reflected by increased NGF expression compared with VPA alone, alongside stronger neuronal-like morphology.