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Minimally Invasive Embedding of Saturated MSU Induces Persistent Gouty Arthritis in Modified Rat Model
Han-Lin Xu1, Sheng-Kun Li1, Xiao-Ao Xue1
1Department of Sports Medicine, Huashan Hospital, Fudan University, No. 12 Urumqi Middle Rd., Shanghai 200040, China.
Introduction:
Animal models are valid for in vivo research on the pathophysiological process and drug screening of gout arthritis. Intra-articular injection of monosodium urate (MSU) is the most common method, while stable MSU deposition enveloped by inflammatory cells was rarely reported.
Objective:
To develop a modified gouty arthritis rat model characterized by intra-articular MSU deposition and continuous joint pain with a minimally invasive method.
Method:
A total of twenty-four rats were randomly allocated into six groups. Three intervention groups of rats received intra-articular MSU embedment. Sham groups received pseudosurgeries with equal normal saline (NS). Gross parameters and pathological features of synovium harvested from anterior capsule were estimated. Mechanical pain threshold tests were conducted over a 96-hour period postoperatively. Moreover, quantitative immunofluorescence was conducted to assess tissue inflammation.
Result:
After MSU embedding, rats got more persistent arthritic symptoms as well as tissue MSU deposition. More significant synovial swelling was detected in the MSU group compared to sham groups (P < 0.025). Behavioral tests showed that the embedding of MSU resulted in prolonged mechanical hyperalgesia during 2 hours to 96 hours postoperatively (P < 0.05). MSU depositions enveloped by inflammatory cells that express IL-1β and TNF-α were detected in embedding groups. Quantitative immunofluorescence suggested that the frequencies of MSU interventions upregulated expression of proinflammatory factors including IL-1β and TNF-α (P < 0.05).
Conclusion:
A minimally invasive method was developed to establish modified rat model of intra-articular MSU deposition. This model was proved to be a simple reproducible method to mimic the pathological characteristics of persistent gouty arthritis.
Insights
A new minimally invasive method creates a modified rat model for gout arthritis, featuring persistent joint pain and monosodium urate (MSU) deposition. This reproducible model aids in studying chronic gouty arthritis and drug screening.
Area of Science:
- Biomedical Research
- Animal Models
- Rheumatology
Background:
- Animal models are crucial for gout arthritis research, but current methods using monosodium urate (MSU) injections rarely achieve stable MSU deposition with chronic inflammation.
- Developing a more representative model is essential for understanding gout pathophysiology and for effective drug screening.
Purpose of the Study:
- To establish a modified rat model of gouty arthritis using a minimally invasive technique.
- The model aims to achieve intra-articular MSU deposition and induce continuous joint pain, mimicking chronic gout symptoms.
Main Methods:
- A minimally invasive intra-articular MSU embedment technique was employed in rats.
- Sham surgeries with normal saline were performed as controls.
- Synovial tissue analysis, mechanical pain threshold tests, and quantitative immunofluorescence for inflammatory markers were conducted.
Main Results:
- The MSU embedding method successfully induced persistent arthritic symptoms and intra-articular MSU deposition.
- Rats in the MSU group exhibited significant synovial swelling and prolonged mechanical hyperalgesia compared to controls.
- MSU deposition was associated with inflammatory cells expressing IL-1β and TNF-α, indicating heightened inflammation.
Conclusions:
- A novel, minimally invasive method for creating a modified rat model of intra-articular MSU deposition was successfully developed.
- This reproducible model effectively mimics the pathological characteristics of persistent gouty arthritis, offering a valuable tool for research.
