Fig. 2

The arginine transporter CAT-1 is overexpressed in RA FLSs and is elevated under hypoxia. a mRNA expression of SLC7 family transporters in 9 RA and OA synovial tissue samples were detected by RT-PCR, and GAPDH was used as the internal control. The P-value was calculated by Student’s test. b Representative image of CAT-1 protein expression in RA FLSs and OA FLSs by Western blots. c The relative protein levels of CAT-1 in RA FLSs and OA FLSs were analyzed, and β-actin was used as the internal control. d Representative images of the protein expression of CAT-1 in RA and OA synovial tissue. e The protein expression of HIF-1α and CAT-1 in RA FLSs cultured under normoxic or hypoxic conditions for 24 h were analyzed by Western blot. f The relative protein levels of HIF-1α and CAT-1, and β-actin was used as the internal control. The data are expressed as the mean ± SD of three independent experiments. *P < 0.05