113: The PICK1 A87L mouse as a tool for uncovering the analgesic mechanism of PICK1 inhibition

Topic: Basic Science
Subtopic: Non-specific to any diagnosis (including studies in healthy animals), Pharmacological interventions, Omics (Proteomics/Metabolomics/Transcriptomics/Genomics), Transgenic models

Background and Aims: The scaffold protein, protein interacting with C kinase 1 (PICK1), is a promising target in chronic pain. Treatment with peripherally restricted PICK1-targeting peptide inhibitors provide relief of pain-like behaviour across rodent models of neuropathic and inflammatory pain. (Jensen 2024) However, the analgesic mechanism of action remains unknown. A mutation in the PICK1 PDZ-domain, A87L, weakens or ablates the binding of interaction partners and inhibitory peptides in vitro. (Christensen 2020) The aim of this project is to generate and characterize a PICK1 A87L knock-in (KI) mouse line to utilize as a tool for uncovering the analgesic mechanism of PICK1 inhibition.

Methods: The PICK1 A87L KI mouse was generated by CRISPR/Cas9. In the spared nerve injury (SNI) model, analgesic efficacy of a PICK1 inhibitor was assessed by measures of evoked and spontaneous pain-like behaviour. Additionally, the mice were characterized in relation to fertility, learning, and metabolism which are deficits of the PICK1 knockout (KO) mouse. Changes in the PICK1 interactome were investigated by co-immunoprecipitation of PICK1 in naïve and spared nerve injury (SNI) mice. Finally, the analgesic mechanism of PICK1 inhibition was investigated by comparing proteomic changes in relevant tissue between wildtype and KI mice.

Results: The PICK1 A87L KI mouse was successfully generated and develops pain-like behaviour after SNI induction to the same extent as wildtype mice. However, the analgesic efficacy of a PICK1 inhibitor is greatly reduced. Thus far, the KI mice do not show deficits in fertility, learning, or metabolism. The PICK1 interactome is expected to be altered compared to wildtype mice specifically for known PDZ-interactors and may show difference between naïve and SNI mice. Proteomic changes are present after treatment with PICK1 inhibitors in wildtype mice. The same study in the KI mice will reveal which changes are specific to PICK1 inhibition.

Conclusions: The PICK1 A87L KI mouse has been generated and does not show behavioural differences from a wildtype mouse apart from analgesic efficacy of PICK1 inhibition. This makes it a clean and valuable tool for investigating the analgesic mechanism of action of PICK1 inhibition. This will be enlightened by assessing proteomic changes after treatment.

References: Jensen KL et al. Peripherally restricted PICK1 inhibitor mPD5 ameliorates pain behaviors in murine inflammatory and neuropathic pain models. JCI Insight. 2024.

Christensen NR et al. A high-affinity, bivalent PDZ domain inhibitor complexes PICK1 to alleviate neuropathic pain. EMBO Mol Med. 2020.

Presenting Author: Ida Buur Kanneworff
Submitting Author: Ida Buur Kanneworff

Senior Author: Kenneth Lindegaard Madsen

IASP 2026 Global Year theme of Neuropathic Pain: Yes

• Kathrine Louise Jensen: Ph.D. - Zyneyro ApS
• Marie Løth Topp: B.Sc. - Zyneyro ApS
• Aina Francès Llueca: B.Sc. - University of Copenhagen
• Jeppe Theisen Pedersen: M.Sc. - University of Copenhagen
• Raquel Comaposada Baro: Ph.D. - University of Copenhagen
• Andreas Toft Sørensen: Ph.D. - Zyneyro ApS
• Kenneth Lindegaard Madsen: Ph.D. - University of Copenhagen