Fig. 3.

Expression of sXBP1 and UPR genes in synovium. (A) sXBP1 mRNA levels in RA and OA-SF determined by qRT-PCR. Statistical significance determined by Mann–Whitney test. (B) Correlation between sXBP1 mRNA levels and synovial inflammation, which was determined using visual analogue scale following arthroscopic inspection of the joint. Statistical significance determined using Spearman rank correlation coefficient (C) SYNV1, HSPA5 and DNAJB9 mRNA levels in RA and OA-SF determined by qRT-PCR. Statistical significance determined by Mann–Whitney test. (D) XBP1 splicing determined by RT-PCR, using primers that amplify both unspliced and spliced mRNA species. Neg, cells at rest; Pos, cells treated with DTT (to induce a UPR). RA SF were obtained from a rheumatoid joint (knee) and cultured to P3, OA SF obtained from an OA patient (knee joint) and cultured to P3.