PI3K/mTOR Signaling Pathway Dual Inhibition for the Management of Neuroinflammation: Novel Insights from In Vitro Models

Neuroinflammatory responses are central to the pathogenesis of neurodegenerative diseases, affecting cells of both neuronal and glial origin that respond to immune-driven inflammatory stimuli. The PI3K/mTOR signaling pathway is essential for the regulation of these neuroinflammatory processes and is therefore a promising target for therapeutic intervention. Here, we investigated the consequences of PI3K/mTOR pathway inhibition on neuroinflammation employing PF-04691502, an agent with combined PI3K and mTOR inhibitory activity. We treated SH-SY5Y, C6, BV-2, and Mo3.13 cell lines with PF-04691502 at concentrations of 0.1, 0.5, and 1 µM to assess the modulation of neuroinflammatory responses. To induce inflammation, cells were stimulated with lipopolysaccharide (LPS, 1 μg/mL) and interferon-gamma (IFN-γ, 100 U/mL). The results from the MTT assays demonstrated that PI3K/mTOR inhibition preserved cell viability at 0.5 and 1 µM across all of the cell lines, indicating its potential to mitigate inflammation-driven cytotoxicity. Subsequent ELISA assays revealed a marked decrease in the NF-κB and pro-inflammatory cytokine levels, confirming the effective suppression of inflammation through PI3K/mTOR inhibition. In addition, the SH-SY5Y cell line was exposed to MPP+ to simulate Parkinson's disease (PD)-like toxicity; then, cell viability, PD-associated markers, and apoptotic indicators were assessed. Our results indicate that inhibition of the PI3K/mTOR signaling axis may alleviate neurodegenerative processes by modulating both neuroinflammatory responses and apoptotic pathways. These findings highlight the therapeutic promise of targeting PI3K/mTOR in the context of neurodegenerative disorders and support the need for further validation through in vivo and clinical investigations.