Fig 1: The expression of CD73 was upregulated in OA. A. The heat map that listed adenosine-related molecules. The colors of each rectangle reflected the expression changes of the corresponding genes in normal and OA populations. B. The quantification of the expression changes of genes encoded adenosine-related molecules in normal and OA populations. C. The PPI network showed the connections between different genes. The more connections between these genes suggested there might be more relevant at molecular level. D. Schematic diagram of dividing the cartilage on the human femoral condyle into intact and damaged areas and extracting proteins respectively. E. Western blot results of CD39, CD73, ADORA1, ADORA2A, ADORA2B and ADORA3 in the intact and damaged areas of OA cartilage. F. The quantification of western blot results. G. Immunofluorescence staining of Cd39, Cd73, Adora1, Adora2a, Adora2b and Adora3 in the mice knees of control and OA groups. H. The quantification of immunofluorescence staining. Data (n ≥ 5 of clinical samples and n = 3 of animal samples) were shown as mean ± SD. ∗P < 0.05; ∗∗P < 0.01; ∗∗∗P < 0.001. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)