Table 2.
The expression changes of key proteins of each signaling pathway in the synovial joint
| Key protein | Expression location in human | Expression in human OA | Expression in animal OA | References |
|---|---|---|---|---|
| FGF1 | Synovial and articular chondrocytes | Upregulation | Upregulation in MIA-induced KOA in rats | PMID: 21835001 |
| FGF2 | Articular chondrocytes | Unknown | low-molecular-weight FGF2 isoform upregulates in spontaneous OA in mice; while loss of high-molecular-weight FGF2 isoforms downregulates in spontaneous OA in mice | PMID: 17960584 |
| FGF7 | OA meniscal cells | Upregulation | Upregulation in human OA meniscal cells | PMID: 20109188 |
| FGF8 | Unknown | Unknown | Produced by injured synovium in DMM-induced OA in rabbit | PMID: 18699993 |
| FGF9 | Articular cartilage | Downregulation | Downregulation in DMM-induced OA in mice; | PMID: 22841919 |
| FGF18 | Articular cartilage | Downregulation | Downregulation in DMM-induced OA in mice; | PMID: 24577103 |
| FGF23 | OA chondrocytes | Upregulation | Upregulation in posttraumatic OA in rats | PMID: 29718273 |
| FGFR1 | Articular cartilage | Upregulation | Upregulation in spontaneous and DMM-induced OA in mice; | PMID: 21835001 |
| FGFR2 | Articular cartilage | Upregulation | PMID: 26400350 | |
| FGFR3 | Articular cartilage; OA synovial tissue | Downregulation | Downregulation in spontaneous and DMM-induced OA in mice; | PMID: 27041063 |
OA osteoarthritis, KOA knee osteoarthritis, FRZB frizzled-related protein, DMM destabilization of the medial meniscus, MIA monosodium iodoacetate, ACLT anterior cruciate ligament transection, STR/ort mice a well-recognized mouse model which develops spontaneous osteoarthritis very similar to the human disease