ALPHA-CLASS, MU-CLASS AND PI-CLASS GLUTATHIONE S-TRANSFERASES IN HUMAN SYNOVIUM AND CULTURED SYNOVIAL FIBROBLASTS - EFFECTS OF INTERLEUKIN-1-ALPHA, HYDROGEN-PEROXIDE AND INHIBITION OF EICOSANOID SYNTHESIS

We describe expression of alpha, mu and pi class glutathione S-transfe rases (GST) and, CuZn- and Mn superoxide dismutase (SOD) in human syno vium and cultured synovial fibroblasts. Immunohistochemical and immuno blotting studies showed synovium and cultured cells expressed pi GST a nd both isoforms of SOD. Cellular localisation was largely perinuclear . No expression of alpha or mu GST was detected even though polymerase chain reaction analysis showed 4/6 subjects had positive genotypes at the polymorphic, mu class GSTM1 locus. Incubation of cultured synovia l fibroblasts with H2O2, IL-1alpha and the cyclooxygenase and lipoxyge nase inhibitor, Tenidap, did not induce expression of alpha, mu or pi GST though treatment with IL-1alpha caused a marked increase in the ex pression of Mn SOD.