Evaluation of Three Growth Factors with the Most Controversial Expression Pattern in Osteoarthritic and Non-osteoarthritic Cartilage

Abstract

There is no clear consensus regarding the expression pattern of many growth factors in healthy and osteoarthritic cartilage. In this study, the expression pattern of three controversial cartilage growth factors was compared between osteoarthritic (n=27) ‎and non-osteoarthritic cartilage samples (n=14). The candidate growth factor included Insulin-like ‎growth factor 1 (IGF-1), Fibroblast Growth Factor 2 (FGF-2), and Bone Morphogenetic Protein 2 (BMP-2). The candidate markers' gene and protein expression were analyzed using relative quantification relative to real-time PCR and ELISA, respectively. The mean IGF-I ‎mRNA and protein expression were 11.1, and 2 folds greater in osteoarthritic cartilage, respectively (p<0.001 for both). The mean FGF-2 ‎mRNA and protein expression were 6.7 and 1.3 folds greater in osteoarthritic cartilage, respectively (p<0.001 and p=0.003). The mean BMP-2 ‎mRNA and protein expression were 3.48 and 1.51 folds greater in osteoarthritic cartilage, respectively (p=0.001 and p<0.001). A significant positive correlation was found between the mRNA and protein expression of all candidate growth factors. In conclusion, the gene and protein expression of IGF-I, FGF-2, and BMP-2 were significantly higher in the ‎osteoarthritic cartilages when compared with non-osteoarthritic, suggesting them as‎‏ a therapeutic ‏target in OA treatment.