Middle-aged mice treated with GHK-Cu peptide administered intraperitoneally or intranasally show behavioral rescue but divergent hippocampal aging programs

Overview

Authors: Jordan Mazzola¹, Manuela Rosenfeld¹, Matthew Tucker¹, Jackson Wezeman¹, Warren Ladiges¹, Gerald Liao¹

University of Washington

Journal: Research square, pages rs.3.rs-9520102

Dates: published online 26 May 2026

Type: Research article · Language: English

License: CC BY

Identifiers: DOI · PMCID PMC13232416

Status: data only (how the code is found and verified)

Categories: genetics / omics (modality), mouse (organism)

Methods: Statistics

Keywords: aging, cognitive decline, GHK-Cu peptide, intraperitoneal delivery, intranasal delivery, RNA sequencing

Citations: 35 references in the paper

Abstract

Age-related cognitive decline (ARCD) is driven by conserved biological mechanisms of aging, yet no gerotherapeutic directly targets these processes in the brain. Glycyl-L-histidyl-L-lysine complexed with copper (GHK-Cu) is an endogenous peptide with regenerative and anti-inflammatory properties that declines with age. Whether its effects on cognitive aging depend on delivery route or exposure duration remains unclear. Aged C57BL/6J mice (20–21 months) received GHK-Cu (15 mg/kg) via short-term intraperitoneal (IP; 5 days) or longer-term intranasal (IN; 8 weeks) administration. Hippocampal-dependent escape learning was assessed using a spatial navigation task. Molecular effects were evaluated using hippocampal immunohistochemistry and bulk RNA sequencing. Differential gene expression was analyzed using DESeq2 with false discovery rate (FDR) correction, and pathway-level changes were assessed via gene set enrichment analysis (GSEA). IN GHK-Cu improved escape latency across Trials 2–4 in both sexes (P < 0.05), whereas IP dosing produced a transient improvement in males during Trial 2 (P < 0.05) without sustained effects or improvement in females. IN treatment increased synaptophysin in females (P < 0.001) and decreased GFAP in both sexes (P < 0.01), while IP treatment reduced TGF-β, GFAP, and MCP-1 in males (P < 0.05) and decreased p21 in females (P < 0.0001). Transcriptomic analysis revealed distinct molecular programs. IN GHK-Cu induced coordinated suppression of oxidative phosphorylation (male NES − 5.44, female NES − 4.20; FDR < 0.0001) and MYC target pathways (female NES − 4.31, FDR < 0.0001), with additional attenuation of PI3K-AKT-mTOR signaling in females (NES − 3.15, FDR = 0.062). In contrast, IP treatment activated oxidative phosphorylation (female NES 4.97, FDR < 0.001), DNA repair (NES 5.58, FDR < 0.001), and MYC targets (NES 4.34, FDR = 0.002), indicating engagement of acute stress-response and repair pathways. GHK-Cu improves hippocampal-dependent learning in aged mice through distinct biological modes: IP exposure activates repair and stress-response pathways, whereas IN delivery induces sustained suppression of growth and mitochondrial metabolic signaling associated with aging biology. These findings demonstrate that functional cognitive improvement can arise from divergent molecular states and identify administrative route and exposure duration as key determinants of gerotherapeutic response.

Reproduced under the paper's license (CC BY), from the paper cited above.

Code

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Data

Datasets cited

bioproject:PRJNA1462979, at NCBI BioProject; found in “Data availability statement.”

Data availability statement

The behavioral and histological data are available from the corresponding author on reasonable request. The RNA-sequencing data generated during the current study are available in the NCBI repository (accession PRJNA1462979: https://www.ncbi.nlm.nih.gov/bioproject/PRJNA1462979).

Reproduced under the paper's license (CC BY), from the paper cited above.

Versions

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Version 1, 28 September 2026: the first record

Recorded: type, language, journal, pages, dates, 6 authors, 6 keywords, 34 references.

Cite

This paper

Mazzola, J., Rosenfeld, M., Tucker, M., Wezeman, J., Ladiges, W., & Liao, G. (2026). Middle-aged mice treated with GHK-Cu peptide administered intraperitoneally or intranasally show behavioral rescue but divergent hippocampal aging programs. Research square, rs.3.rs-9520102.

BibTeX

@article{mazzola2026middle, author = {Mazzola, Jordan and Rosenfeld, Manuela and Tucker, Matthew and Wezeman, Jackson and Ladiges, Warren and Liao, Gerald}, title = {{Middle-aged mice treated with GHK-Cu peptide administered intraperitoneally or intranasally show behavioral rescue but divergent hippocampal aging programs}}, journal = {Research square}, year = {2026}, month = may, pages = {rs.3.rs--9520102}, publisher = {Research Square}, issn = {2693-5015}, pmcid = {PMC13232416} }

RIS

TY - JOUR AU - Mazzola, Jordan AU - Rosenfeld, Manuela AU - Tucker, Matthew AU - Wezeman, Jackson AU - Ladiges, Warren AU - Liao, Gerald TI - Middle-aged mice treated with GHK-Cu peptide administered intraperitoneally or intranasally show behavioral rescue but divergent hippocampal aging programs T2 - Research square J2 - Res Sq PY - 2026 DA - 2026/05/26 SP - rs.3.rs EP - 9520102 SN - 2693-5015 PB - Research Square LA - en ER -

CSL-JSON

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