Regulatory Role of Nitric Oxide in Neutrophil Apoptosis

Abstract

Apoptosis of blood neutrophils from healthy donors was studied under conditions of cell culturing with different concentrations of H(2)O(2), selective NO synthase inhibitor, and inductor of NO synthesis (L-arginine). In vitro incubation of neutrophilic leukocytes with 5 mM H(2)O(2) led to activation of the apoptotic program in neutrophils, which was seen from increased content of Bax protein in the cells and increased number of apoptotic cells in the culture. Increased content of annexin-positive cells after incubation of neutrophil culture with NO synthase inhibitor suggests involvement of NO in the regulation of neutrophil apoptosis under conditions of oxidative stress, while L-arginine prevented H(2)O(2)-induced programmed cell death.

Effects on Alimentary High-Fat Diet on Thiol Disulfide Homeostasis in Rats

“…The regulation of the main biological processes in the cells is associated with changes in the redox status of thiol groups in proteins [4,5]. The role of reduced glutathione as the redox buffer and antioxidant essential for the maintenance of the protein thiol disulfi de status and cell protection from oxidative stress in aging, cancer, neurodegenerative and infl ammatory diseases, is suffi ciently well studied [7]. Antioxidant activity of glutathione is catalyzed by glutathione peroxidase (GP) and glutathione reductase (GR).…”

Role of Hydrogen Sulfide in the Regulation of Cell Apoptosis

“…1. Number of necrotic (1, 3) and apoptotic Jurkat cells (2,4) after treatment with NaHS for 15 min (1, 2) and 2 h (3, 4). incubation), which was related to rapid dissociation of the donor in an aqueous solution (Fig.…”

“…H 2 S is the third (after NO and CO) endogenous gas transmitter. H 2 S serves as a signal molecule in the regulation of cardiovascular and nervous functions and realization of the infl ammatory process [2,8].…”

Role of Thiol-Disulfide System in Mechanisms of Functional Changes in Neutrophils under Conditions of Oxidative Stress

“…Neutrophil leukocytes are the main producers of ROS essential for elimination of the phlogogen. However, this simultaneously leads to exhaustion of antioxidant defense reserves in neutrophils, prooxidant shift of the redox status, and dysregulation of intra-and extracellular redox-dependent signal transduction pathways [4,5,6]. The molecular mechanisms of ROS interaction with the phlogogen and tissues are studied in detail [2,4,5], but little is known about the effect of free radicals directly on the redox state of neutrophils.…”

“…The molecular mechanisms of ROS interaction with the phlogogen and tissues are studied in detail [2,4,5], but little is known about the effect of free radicals directly on the redox state of neutrophils. Due to their high reaction capacity, ROS induce oxidative modifi cation of macromolecules in the target cells and neutrophils, which modulates the functional state of phagocytizing cells and induces their apoptosis [4,6,14]. An essential role in the maintenance of cell redox-potential determining the effi ciency of their functioning is played by the thiol-disulfi de system.…”