Interferon-γ Mitigates Oxaliplatin-Induced Neurotoxicity: Analogies With Connexin 43.

AIMS: Chemotherapy-induced neuropathy is a major side effect of platinum-based drugs such as oxaliplatin. Given the context-dependent pro-inflammatory or neuroprotective actions of interferon-γ (IFN-γ), this study investigated its role in an in vitro model of oxaliplatin-induced neurotoxicity (OIPN).

METHODS

Rat organotypic spinal cord slices were exposed to oxaliplatin to model chemotherapy-induced neurotoxicity responses in vitro. IFN-γ cytotoxicity was assessed at 6 and 24 h. Neurotoxicity, inflammatory mediators, neurotrophic factors, and markers of glial and neuronal activation were analyzed by biochemical and immunohistochemical assays. Connexin 43 (Cx43) was assessed using Gap19 and Gap27 to probe hemichannel and gap-junction contributions. Electrophysiological recordings characterized neuronal excitability.

RESULTS

IFN-γ (6.5-200 ng/mL) was non-toxic and, at 65 ng/mL, significantly reduced oxaliplatin-induced neurotoxicity, decreasing LDH release and suppressing pro-inflammatory mediators (CCL2, SerpinA3N, CGRP, substance P, c-Fos). IFN-γ modulated its signaling by reducing IFNγR and increasing IRF1 expression. It prevented oxaliplatin-induced overexpression of neurotrophic factors and reduced glial and neuronal hyperactivation markers, preserving neuronal integrity. IFN-γ reduced Cx43 expression and hemichannel activity, and Gap19 reproduced selected protective effects. Electrophysiology showed attenuation of oxaliplatin-induced neuronal hyperexcitability.

CONCLUSION

IFN-γ attenuates oxaliplatin-induced neurotoxic responses in an in vitro spinal cord model. The parallel reduction in Cx43 expression and hemichannel activity supports further investigation of Cx43 signaling as a candidate pharmacological target in OIPN.