Fig. 7

Prok2 is not detected in the sera of OA model mice or human OA patients. A Primary-culture mouse chondrocytes were infected with 800 MOI of Ad-C, Ad-HIF-2α, or Ad-Prok2 for 36 h. Five milliliters of cell culture supernatant from five 35-mm dishes was concentrated to 100 μl an ELISA was used to detect secreted Prok2 (n=8 independent cultures). B Sera were collected from mice IA injected in both knees with 1 × 10⁹ pfu of Ad-C, Ad-HIF-2α, or Ad-Prok2 once a week for 3 weeks. Prok2 levels in 100 μl of collected sera were determined by ELISA (n=8 mice per group). C Sera was collected from mice that were sham- or DMM-operated in both knees and sampled at 8 weeks after the operation. Prok2 levels were determined by ELISA from 100 μl of collected sera (n=18 mice per group). D Prok2 levels were determined from 100 μl of sera collected from KL grade 0 non-OA individuals and KL grade 3~4 OA patients (n=18 females per group). Because the Prok2 levels in all samples (except the Ad-Prok2-infected chondrocytes in A) were below the range of detection, the detected values are presented as optical density. Statistical values are presented as means ± s.e.m, and were assessed with paired t-test for ELISA of cell culture media, ANOVA with Bonferroni’s post hoc test for ELISA of mouse serum, and Student’s t test for ELISA of human serum