Unveiling the peripheral nerve hallmarks of chemotherapy-induced neuropathy: insights from paclitaxel treatment in a murine model

• Paclitaxel induces dose-specific neuropathic pain symptoms and sciatic nerve dysfunction. • TRPV1 and CGRP expression in skin nerve endings is significantly upregulated. • Schwann cell dysfunction is linked to disrupted myelin and altered autophagic mechanisms. • Metabolic changes in glucose and triglycerides correlate with neuropathy development. • Macrophage and mast cell infiltration suggests an inflammatory response in neuropathy. Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent and debilitating side effect of anticancer drugs like paclitaxel, significantly reducing the quality of life for cancer patients. Paclitaxel-induced peripheral neuropathy (PIPN) is primarily characterized by sensory disturbances such as mechanical allodynia and thermal hyperalgesia. Despite its prevalence, the mechanisms driving PIPN are not fully understood, and current treatment options remain limited. This study explores the impact of varying doses of paclitaxel on neuropathic pain, nerve structural changes, and metabolic alterations in a mouse model. Behavioural assessments demonstrated that paclitaxel induced dose-dependent mechanical allodynia and thermal hyperalgesia, with prolonged symptoms at higher doses. Furthermore, sciatic nerve dysfunction was observed, while metabolic tests revealed significant disruptions in glucose and triglyceride levels, suggesting a link between metabolic imbalances and neuropathy. Histological and molecular analyses identified increased TRPV1 and CGRP expression in skin nerve fibers, accompanied by Schwann cell dysfunction, characterized by myelin disorganization, decreased levels of myelin proteins (P0, MBP), and elevated LC3 levels, pointing to autophagy involvement. Moreover, infiltration of macrophages and mast cells into sciatic nerves indicated an innate immune response. These results emphasize the complex nature of PIPN, which involves sensory nerve sensitization, Schwann cell damage, and metabolic dysregulation. Elucidating these pathways could inform the development of more effective therapies aimed at preventing or alleviating the impact of CIPN.