Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jul 5;26(1):653.
doi: 10.1186/s12891-025-08898-0.

Association of glutamine metabolites in synovial fluid with the severity of temporomandibular joint osteoarthritis

Zhiqiang Song  1 , Yingjie Xu  2   1 , Chenxi Li  2   1 , Bo Shao  3   4 , Zhongcheng Gong  5   6
Affiliations

Association of glutamine metabolites in synovial fluid with the severity of temporomandibular joint osteoarthritis

Zhiqiang Song et al. BMC Musculoskelet Disord. .

Abstract

Background: The aim of this study was to compare the levels of glutamine and its metabolites, including glutamate, glutaminase (GLS), and α-ketoglutarate (α-KG), in the synovial fluid (SF) of temporomandibular joint osteoarthritis (TMJ-OA) and temporomandibular joint internal derangement (TMJ-ID) patients. Correlations between these factors and TMJ-OA severity were assessed, and changes in these factors before and after hyaluronic acid (HA) treatment were analysed.

Methods: SF samples from 30 patients with unilateral TMJ-ID and unilateral TMJ-OA were analysed, along with visual analogue scale (VAS) scores, maximum mouth opening (MMO), and radiographic stages. The SF levels of glutamine, glutamate, GLS, and α-KG were determined via an enzyme-linked immunosorbent assay. Spearman correlation was used to assess the relationships between SF components and VAS scores, MMO, and imaging severity. ROC curve analysis was used to evaluate each factor's ability to predict TMJ-OA and TMJ-ID. To assess the efficacy of HA treatment for TMJ-OA, VAS scores, MMO, and these factors in SF were also compared in patients in the TMJ-OA group who had received an intra-articular injection of HA.

Results: SF levels of glutamate and GLS were significantly greater in the TMJ-OA group than in the TMJ-ID group, whereas glutamine and α-KG levels were lower. The glutamine SF level was negatively correlated with the radiographic stage (r = -0.5439, P = 0.0019) and MMO (r = -0.4784, P = 0.0075), whereas glutamate was positively correlated with VAS score (r = 0.6681, P = 0.0001). Glutamate shows promise as a TMJ-OA diagnostic marker. The-cut-off value of glutamate in SF was 0.12 µM/ml, with an area under the curve value of 0.9394 for predicting TMJ-OA. After HA injection for TMJ-OA, the MMO improved, and the VAS score and glutamate level decreased significantly (all P < 0.05).

Conclusions: Our results indicate alterations in glutamine metabolism in patients with TMJ-OA. Glutamate has potential as a diagnostic marker for TMJ-OA. The concentration of glutamine was associated with the radiographic stage and MMO of TMJ-OA patients, whereas the glutamate level was correlated with VAS pain intensity. The glutamine metabolic pathway may be critical in the pathogenesis of TMJ-OA.

PubMed Disclaimer

Conflict of interest statement

Declarations. Ethics approval and consent to participate: The Ethical Committee of the First Affiliated Hospital of Xinjiang Medical University approved this study (number K202501-10), and all patients provided signed consent. Consent for publication: Applicable. Competing interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Protocol and synovial fluid sample collection
Fig. 2
Fig. 2
The correlation between the SF level of glutamine and the severity of TMJ-OA
Fig. 3
Fig. 3
The correlation between the SF level of glutamate and the severity of TMJ-OA
Fig. 4
Fig. 4
Receiver operating characteristic curve analysis of various factors in SF. A: glutamine, B: glutamate, C: glutaminase, D: α-ketoglutarate
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Shao B, Xu Y, Jia M, Li C, Gong Z. Association of HMGB1 levels in synovial fluid with the severity of temporomandibular joint osteoarthritis. BMC Musculoskelet Disord. 2023;24(1):183. - PMC - PubMed
    1. Yang B, Li X, Fu C, Cai W, Meng B, Qu Y, Kou X, Zhang Q. Extracellular vesicles in osteoarthritis of peripheral joint and temporomandibular joint. Front Endocrinol (Lausanne). 2023;14:1158744. - PMC - PubMed
    1. Zhang D, Zhang Y, Xia S, Shen P, Yang C. Metabolic profiling of synovial fluid in human temporomandibular joint osteoarthritis. Front Immunol. 2024;15:1335181. - PMC - PubMed
    1. Juan Z, Xing-Tong M, Xu Z, Chang-Yi L. Potential pathological and molecular mechanisms of temporomandibular joint osteoarthritis. J Dent Sci. 2023;18(3):959–71. - PMC - PubMed
    1. Roos EM, Arden NK. Strategies for the prevention of knee osteoarthritis. Nat Rev Rheumatol. 2016;12(2):92–101. - PubMed

MeSH terms

LinkOut - more resources