Cell Death and Differentiation (2003) 10, 418–430 & 2003 Nature Publishing Group All rights reserved 1350-9047/03 $25.00 www.nature.com/cdd Review Nitric oxide: a key regulator of myeloid inflammatory cell apoptosis Introduction EL Taylor*,1, IL Megson2, C Haslett1 and AG Rossi1 The free radical nitric oxide (NO) was first discovered as an 1 Centre for Inflammation Research, Rayne Laboratory, University of Edinburgh, endogenous vasodilator released from the endothelium to Medical School, Teviot Place, Edinburgh EH8 9AG, UK regulate vascular tone.1 However, it is now known that NO is a 2 Centre for Cardiovascular Science, University of Edinburgh, Hugh Robson key mediator in a great number of physiological and Building, George Square, Edinburgh EH8 9XD, UK pathophysiological processes (see Quinn).2 This ubiquitous * Corresponding author: EL Taylor, Centre for Inflammation Research, Rayne Laboratory, University of Edinburgh, Medical School, Teviot Place, Edinburgh signalling molecule can regulate the rate of apoptosis, or EH8 9AG, UK. Tel.: +44 131 651 1323; Fax: +44 131 650 4384; programmed cell death, in many cell types, including human E-mail:
[email protected] inflammatory cells. Whether or not cells undergo apoptosis depends on the net balance of a large number of pro- versus Received 30.4.02; revised 29.8.02; accepted 2.9.02 antiapoptotic factors. Studies have revealed that NO Edited by G. Melino has both pro and antiapoptotic properties, depending largely on the concentration and flux of NO, and the cell type under scrutiny (for reviews, see Nicotera et al.3 and Kim et Abstract al.4).