Amphiregulin areg

Skin biopsy specimens (6 mm) were obtained from both the lesional skin of patients with psoriasis and the skin of individuals without psoriasis under an Oregon Health & Science University Institutional Review Board-approved protocol. The epidermis was trimmed off and minced into 1×1 mm² skin islets. The skin islets were planted on collagen-coated plates as described[20 (link)]. Keratinocytes from the outgrowth were trypsinized and plated in 12-well plates for the assay. The keratinocyte cultures were switched to CnT-07 keratinocyte medium (Zen Bio) that contains 10 ng/ml EGF or Epilife medium with or without human keratinocyte growth supplement (Invitrogen) that contains 0.2 ng/ml EGF for 3 days before cytokine treatments, which included 10 ng/ml TNFα (Prospec), 20 ng/ml IL-17A (Cell Signaling), 20 ng/ml IL-22 (Cell Signaling), 10 ng/ml interferonγ (Prospec), 20 ng/ml IL-17F (Cell Signaling), and 10 ng/ml growth factors EGF (Millipore), 10 ng/ml transforming growth factor alpha (TGFα; Biolegend), amphiregulin (AREG; R&D Systems), and 10 ng/ml HB-EGF (R&D Systems) as indicated. The EGFR inhibitors erolotinib, gefitinib, and lapatinib were purchased from SelleckChem. The toll like receptor (TLR) agonist peptidoglycan was purchased from Sigma.