# Olink proteomics identifies FGF-19 as a treatment-responsive inflammatory biomarker associated with acupuncture intervention in young females with mild depression

## TL;DR

This study finds that FGF-19 is a treatment-responsive inflammatory biomarker linked to acupuncture in young women with mild depression.

## Contribution

FGF-19 is identified as a novel, treatment-responsive inflammatory biomarker for mild depression in young females following acupuncture.

## Key findings

- FGF-19 was significantly downregulated in mild depression and upregulated after acupuncture.
- FGF-19 levels were inversely correlated with depression scores and validated in an expanded cohort.
- Acupuncture modulated inflammatory proteins, with FGF-19 showing a bidirectional expression profile.

## Abstract

Mild depression in women is a distinct disorder with unclear immune mechanisms. This study aims to identify peripheral inflammatory biomarkers and to explore acupuncture’s immunomodulatory effects via Olink proteomics. Thirty female participants (18–45 years) were assigned to healthy controls (HC), mild depression (MD), and acupuncture treatment (ACU). Plasma samples were analyzed using the Olink® Target 96 Inflammation panel for differentially expressed proteins (DEPs) (Approval No. KY-2023-005-02), then analyzed for enrichment using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Correlations between DEPs and Hamilton Depression Rating Scale-17 items (HAMD-17) and Self-Rating Depression Scale (SDS) scores were assessed. Enzyme-linked immunosorbent assay (ELISA) was conducted on an expanded cohort (n=40/group) to validate key findings. Compared with HC, 15 proteins were significantly downregulated in MD (no proteins were upregulated), including FGF-19, SIRT2, and AXIN1. After acupuncture, six proteins were further downregulated, and three (FGF-19, FGF-5, IL-2) were significantly upregulated. ELISA validation confirmed that FGF-19, the sole protein significantly altered, was inversely correlated with depression scores and exhibited decreased expression in MD that was reversed by acupuncture. FGF-19’s bidirectional expression profile positions a promising inflammation-related biomarker and a potential treatment-responsive marker for mild depression in young females, also an indicator of acupuncture efficacy. Clinical Trial Registration Chinese Clinical Trial Registry, identifier ChiCTR2300068054.

https://www.chictr.org.cn/showprojEN.html?proj=189355, identifier ChiCTR2300068054.

Flowchart diagram outlining a study workflow for sample collection in females aged eighteen to forty-five, comparing healthy controls, mild depression cases, and an acupuncture group through bioinformatics analysis, FGF-19 identification, and ELISA validation as a potential inflammatory biomarker.