Kappa opioid receptors mediate an initial aversive component of paclitaxel-induced neuropathy

• Published in: Psychopharmacology 2020-09, Vol.237 (9), p.2777-2793
• Main Authors: Meade, Julie A., Alkhlaif, Y., Contreras, K. M., Obeng, S., Toma, W., Sim-Selley, L. J., Selley, D. E., Damaj, M. I.
• Format: Article
• Language: English
• Subjects: Agonists; Amygdala; Amygdala - drug effects; Amygdala - metabolism; Animals; Antineoplastic Agents, Phytogenic - toxicity; Avoidance Learning - drug effects; Avoidance Learning - physiology; Biomedical and Life Sciences; Biomedicine; Cancer; Caudate-putamen; Chemotherapy; Depression, Mental; Dose-Response Relationship, Drug; Dynorphin; G proteins; Guanosine 5'-O-(3-Thiotriphosphate) - metabolism; Hypersensitivity; Male; Mental depression; Mice; Mice, Inbred C57BL; mRNA; Narcotics; Neurosciences; Nucleus accumbens; Nucleus Accumbens - drug effects; Nucleus Accumbens - metabolism; Opioid receptors (type kappa); Original Investigation; Paclitaxel; Paclitaxel - toxicity; Patients; Peripheral Nervous System Diseases - chemically induced; Peripheral Nervous System Diseases - metabolism; Peripheral neuropathy; Pharmacology/Toxicology; Polymerase chain reaction; Prodynorphin; Psychiatry; Putamen; Receptors, Opioid, kappa - metabolism; RNA; Spinal cord; Sucrose
• ISSN: 0033-3158; 1432-2072
• DOI: 10.1007/s00213-020-05572-2

Rationale Cancer patients receiving the antineoplastic drug paclitaxel report higher incidences and longer duration of treatment-resistant depression than patients receiving other classes of chemotherapeutics. Rodents treated with paclitaxel exhibit a suite of changes in affect-like behaviors. Further, paclitaxel causes chemotherapy-induced peripheral neuropathy (CIPN) in humans and rodents. Kappa opioid receptors (KOR) have a well-established role in depression and neuropathy. The contributions of KOR signaling to paclitaxel-induced aversive-like state and CIPN in rodents remain to be explored. Objectives We aimed to investigate whether dysregulation of the KOR/dynorphin system is associated with paclitaxel-mediated pain-like behavior and depression-like behavior. Methods Cancer-free male C57BL/6J mice were treated with four injections of vehicle or paclitaxel (32 mg/kg cumulative). The effects of the selective KOR antagonist norbinaltorphimine (norBNI) on paclitaxel-induced sucrose preference deficits and mechanical hypersensitivity were measured. Prodynorphin mRNA and receptor-mediated G protein activation were measured at two time points following the last paclitaxel injection using quantitative real-time polymerase chain reaction and agonist-stimulated [ 35 S]guanosine-5′-O′-(γ-thio)-triphosphate ([ 35 S]GTPγS) binding, respectively, in the nucleus accumbens (NAc), caudate-putamen, amygdala, and spinal cord. Results Paclitaxel produced a norBNI-reversible sucrose preference deficit, whereas mechanical hypersensitivity was not reversed by norBNI. Paclitaxel treatment increased the levels of mRNA for prodynorphin, a precursor for endogenous KOR agonists, in the NAc. Paclitaxel also had time-dependent effects on KOR-mediated G protein activation in the NAc. Conclusions These results suggest that KOR signaling mediates an initial aversive component of paclitaxel, but not necessarily paclitaxel-induced mechanical hypersensitivity.