Figure 1From: CYB5A polymorphism increases androgens and reduces risk of rheumatoid arthritis in women Analysis of pregnenolone metabolism in rheumatoid arthritis synovial fibroblasts. (A) Pathways and enzymes of pregnenolone metabolism as identified in synovial fibroblasts (reviewed in a previous publication [29]). (B, D) Two-dimensional thin layer chromatography (2D-TLC) separation of pregnenolone and its metabolites. (B) Position of unlabeled steroid standards of identified metabolites (circles) overlaid to the 3H-image of the pregnenolone substrate used. (C) 3H-image from a GG-fibroblast line accumulating (besides compound X) 17α-hydroxy-pregnenolone, the direct product 17α-hydroxylase activity, together with 7α-hydroxy-dehydroepiandrosterone (DHEA). (D) 3H-image from an AG-fibroblast line accumulating almost exclusively 7α-hydroxy-DHEA. CYB5A, cytochrome b5, type A; CYP17A1, steroid 17α-hydroxylase/17,20-lyase (cytochrome P450 17A1). E2 was found in a minority of fibroblasts only. *Start indicates point of sample application. X indicates the major product formed from pregnenolone by fibroblasts independently from rs1790834 genotype. Arrows indicate the metabolites with production dependent on the rs1790834 genotype. CYP7B1, 25-hydroxycholesterol 7α-hydroxylase (cytochrome P450 7B1); HSD3B, 3β-hydroxysteroid dehydrogenase; Δ5Adiol, Δ5-androstenediol; Adione, androstenedione; Preg, pregnenolone; Prog, progesterone; Testo, testosterone. E2, estradiol.Back to article page