Glioprotective effects of gM-CSF against glutamate-induced oxidative stress, genotoxicity, and inflammation in rat C6 cells

BACKGROUND: Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) is primarily known for hematopoiesis but has recently shown potential neuroprotective properties. This study investigated the glioprotective mechanisms of GM-CSF against glutamate-induced excitotoxicity in a rat C6 glioma cell line by examining multiple intertwined pathways. METHODS: intracellular ROS levels and antioxidant enzyme activities (SOD, CAT, GPx), while pro-inflammatory cytokine release was quantified by measuring TNF-α, IL-1β, and IL-6 concentrations. Furthermore, specific cellular mechanisms were investigated through assays quantifying ATP production, mitochondrial membrane potential and autophagosome quantification. RESULTS: Glutamate exposure significantly compromised cell survival and induced severe oxidative stress, DNA damage, inflammation, ATP depletion, mitochondrial depolarization, and increased autophagosome formation. However, pretreatment with GM-CSF (10-60 ng/mL) exerted a robust, dose-dependent protective effect across all measured parameters. Specifically, GM-CSF significantly restored cell viability, antioxidant enzyme activities (SOD, CAT, GPx), suppressed ROS accumulation, reduced DNA fragmentation, inhibited pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), and effectively inhibited apoptosis. Crucially, GM-CSF also preserved mitochondrial membrane potential, maintained cellular ATP levels, and suppressed glutamate-induced autophagosome accumulation, confirming its multifaceted mechanism. CONCLUSION: In conclusion, GM-CSF effectively mitigates glutamate-induced toxicity in C6 glioma cells by counteracting oxidative stress, preserving genomic integrity, suppressing pro-inflammatory cytokine release, inhibiting apoptosis, maintaining mitochondrial function, stabilizing energy metabolism, and modulating autophagy. These findings highlight the extensive protective mechanism of GM-CSF and support its potential as a therapeutic candidate for attenuating excitotoxic damage.