Cysteine Redox Potential Determines Pro-Inflammatory IL-1β Levels

Background Cysteine (Cys) and its disulfide, cystine (CySS) represent the major extracellular thiol/disulfide redox control system. The redox potential (Eh) of Cys/CySS is centered at approximately −80 mV in the plasma of healthy adults, and oxidation of Eh Cys/CySS is implicated in inflammation associated with various diseases. Methodology/Principal Findings The purpose of the present study was to determine whether oxidized Eh Cys/CySS is a determinant of interleukin (IL)-1β levels. Results showed a 1.7-fold increase in secreted pro-IL-1β levels in U937 monocytes exposed to oxidized Eh Cys/CySS (−46 mV), compared to controls exposed to a physiological Eh of −80 mV (P