FIGURE 4:

Increased parathyroid TGFα and ADAM17 concur with low VDR and C/EBPβ in human hyperplastic glands from SHPT. (A) Promoter–reporter assay of human ADAM17-promoter activity, corrected by βgal, in A431 cells treated with vehicle (control) or TGFα 8 nM (TGFα), and transfected with empty vector (control + empty vector) or with a C/EBPβ expression vector. Bars and error bars represent the mean ± SEM from six and two independent experiments with triplicate determinations each, for TGFα treatment or upon ectopic C/EBPβ expression, respectively. Results are expressed as % of respective controls. (B) Top panels: representative immunofluorescence of ADAM17, TGFα, VDR and C/EBPβ expression and co-localization in two distinct areas from a single patient. Merge 1: Hoechst (blue), ADAM17 (green); TGFα (red); Merge 2: Hoechst (blue); VDR (gray); C/EBPβ (red); ADAM17 (green). Magnification ×40. Bottom panel: (left) correlation between parathyroid ADAM17 and TGFα in 11 nodules from the PTGs from four patients: r² = 0.571, P = 0.007. Bottom panel (right): correlation between parathyroid ADAM17 and C/EBPβ in eight nodules from the PTGs from six patients: r² = 0.572, P = 0.03.