Ruths L, Huber-Lang M, Schulze-Tanzil G, Riegger J. Anaphylatoxins and their corresponding receptors as potential drivers in cartilage calcification during osteoarthritis progression.
Osteoarthritis Cartilage 2024;
32:514-525. [PMID:
38242312 DOI:
10.1016/j.joca.2024.01.004]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 01/08/2024] [Accepted: 01/12/2024] [Indexed: 01/21/2024]
Abstract
OBJECTIVE
The complement cascade as major fluid phase innate immune system is activated during progression of osteoarthritis (OA). Generated anaphylatoxins and the corresponding receptors C3aR and C5aR1 are associated with the calcification of blood vessels and involved in osteogenic differentiation. This study aims on elucidating whether complement activation products contribute to cartilage calcification of OA cartilage.
METHOD
Human articular chondrocytes were osteogenically differentiated in vitro in the presence or absence of C3a, C5a, and bone morphogenetic protein (BMP) 2. Furthermore, macroscopically intact (OARSI grade ≤ 1) and highly degenerated human cartilage (OARSI grade ≥ 3) was used for C3aR and C5aR1 histochemistry. Calcification of the cartilage was assessed by Alizarin Red S and von Kossa staining.
RESULTS
C3a and C5a amplified matrix mineralization during in vitro osteogenesis, while inhibition of the corresponding receptors impaired calcium deposition. Moreover, C3aR and C5aR1 expression was upregulated during osteogenic differentiation and also in degenerated cartilage. Additionally, anaphylatoxin receptor expression was positively associated with calcification of native cartilage tissue and calcium deposition during osteogenic differentiation. Finally, the pro-hypertrophic growth factor BMP2 induced the expression of C5aR1.
CONCLUSIONS
Our findings indicate that anaphylatoxins and their receptors play a decisive role in cartilage calcification processes during OA progression.
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