Dermatology Commons^™

Effect Of Oxidative Stress On Protein Tyrosine Phosphatase 1b In Scleroderma Dermal Fibroblasts., Pei-Suen Tsou, Nadine N. Talia, Adam J. Pinney, Ann Kendzicky, Sonsoles Piera-Velazquez, Sergio A. Jimenez, James R. Seibold, Kristine Phillips, Alisa E Koch

Department of Dermatology and Cutaneous Biology Faculty Papers

OBJECTIVE: Platelet-derived growth factor (PDGF) and its receptor, PDGFR, promote fibrosis in systemic sclerosis (SSc; scleroderma) dermal fibroblasts, and such cells in scleroderma skin lesions produce excessive reactive oxygen species (ROS). PDGFR is phosphorylated upon PDGF stimulation, and is dephosphorylated by protein tyrosine phosphatases (PTPs), including PTP1B. This study was undertaken to determine whether the thiol-sensitive PTP1B is affected by ROS in SSc dermal fibroblasts, thereby enhancing the phosphorylation of PDGFR and synthesis of type I collagen. This study also sought to investigate the effect of a thiol antioxidant, N-acetylcysteine (NAC), in SSc.

METHODS: Fibroblasts were isolated from the skin …

Elevated Expression Of Type Vii Collagen In The Skin Of Patients With Systemic Sclerosis. Regulation By Transforming Growth Factor-Beta., Lidia Rudnicka, John Varga, Angela M. Christiano, Renato V. Iozzo, Sergio A. Jimenez, Jouni Uitto

Department of Dermatology and Cutaneous Biology Faculty Papers

A hallmark of systemic sclerosis (SSc) is the development of tissue fibrosis. Excessive production of several connective tissue components normally present in the dermis, including type I, III, V, and VI collagens as well as fibronectin and proteoglycans, is a consistent finding in the skin of SSc patients. Type VII collagen is a major constituent of anchoring fibrils, present in the skin at the dermal-epidermal basement membrane zone. TGF-beta has been shown to upregulate the expression of the type VII collagen gene. In this study, we assessed the expression of type VII collagen and TGF-beta in the skin of patients …