# TLR3 and GLUL orchestrate inflammatory and homeostatic imbalance in osteoarthritis

**Authors:** Jing Wang, Shenghao Xu, Bo Chen, Peiqiang Peng, Kai Wang, Yanguo Qin

PMC · DOI: 10.3389/fimmu.2025.1650375 · Frontiers in Immunology · 2026-01-23

## TL;DR

This study identifies TLR3 and GLUL as key regulators of inflammation and tissue balance in osteoarthritis, offering new targets for diagnosis and treatment.

## Contribution

The study reveals TLR3 and GLUL as novel regulators of inflammation and homeostasis in osteoarthritis through integrated bioinformatics and experimental validation.

## Key findings

- TLR3 is upregulated and linked to pro-inflammatory immune cells in osteoarthritis.
- GLUL overexpression promotes cellular homeostasis and reduces inflammation in chondrocytes.
- TLR3 inhibition and PRP treatment in rats reduced inflammation and restored matrix integrity.

## Abstract

Osteoarthritis (OA) is a degenerative joint disease marked by chronic inflammation, extracellular matrix degradation, and dysregulated cell death. The roles of apoptosis-, autophagy-, and ferroptosis-related genes in OA pathogenesis remain unclear.

Integrated bioinformatics analyses were conducted on public GEO datasets to identify apoptosis-autophagy-ferroptosis-related genes (AAFRGs). TLR3 and GLUL were identified using LASSO, random forest, and SVM-RFE algorithms. Immune infiltration analysis, immunohistochemistry, and functional assays in human chondrocytes were performed, and ACLT-induced rat OA models were used for in vivo validation.

TLR3 was upregulated and associated with pro-inflammatory immune cells, while GLUL was downregulated and correlated with anti-inflammatory signatures. TLR3 knockdown reduced inflammation, apoptosis, and aberrant mineralization, partially restoring extracellular matrix integrity. GLUL overexpression promoted cellular homeostasis. In rats, TLR3 inhibition and PRP treatment decreased pro-inflammatory cytokines (IL-1β, TNF-α), reduced matrix-degrading enzymes (MMP3, MMP13), and restored GLUL and IL-10 levels.

TLR3 and GLUL orchestrate inflammatory responses and homeostatic imbalance in OA, representing potential biomarkers and therapeutic targets for diagnosis and intervention.

## Linked entities

- **Genes:** TLR3 (toll like receptor 3) [NCBI Gene 7098], GLUL (glutamate-ammonia ligase) [NCBI Gene 2752], IL1B (interleukin 1 beta) [NCBI Gene 3553], TNF (tumor necrosis factor) [NCBI Gene 7124], MMP3 (matrix metallopeptidase 3) [NCBI Gene 4314], MMP13 (matrix metallopeptidase 13) [NCBI Gene 4322], IL10 (interleukin 10) [NCBI Gene 3586]
- **Diseases:** osteoarthritis (MONDO:0005178)
- **Species:** Homo sapiens (taxon 9606), Rattus norvegicus (taxon 10116)

## Full-text entities

- **Genes:** Il1b (interleukin 1 beta) [NCBI Gene 24494] {aka IL-1F2}, Tlr3 (toll-like receptor 3) [NCBI Gene 364594], Mmp3 (matrix metallopeptidase 3) [NCBI Gene 171045] {aka MMP-3, SL-1}, Tnf (tumor necrosis factor) [NCBI Gene 24835] {aka RATTNF, TNF-alpha, Tnfa}, Glul (glutamate-ammonia ligase) [NCBI Gene 24957] {aka Glns}, Il10 (interleukin 10) [NCBI Gene 25325] {aka IL10X, If2a}, Mmp13 (matrix metallopeptidase 13) [NCBI Gene 171052]
- **Diseases:** inflammation (MESH:D007249), OA (MESH:D010003), degenerative joint disease (MESH:D019636)
- **Chemicals:** ACLT (-)
- **Species:** Homo sapiens (human, species) [taxon 9606], Rattus norvegicus (brown rat, species) [taxon 10116]

## Full text

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## Figures

9 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12875911/full.md

## References

22 references — full list in the complete paper: https://tomesphere.com/paper/PMC12875911/full.md

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Source: https://tomesphere.com/paper/PMC12875911