Metabolic requirements for neutrophil extracellular traps formation

Abstract

Summary As part of the innate immune response, neutrophils are at the forefront of defence against infection, resolution of inflammation and wound healing. They are the most abundant leucocytes in the peripheral blood, have a short lifespan and an estimated turnover of 1010 to 1011 cells per day. Neutrophils efficiently clear microbial infections by phagocytosis and by oxygen‐dependent and oxygen‐independent mechanisms. In 2004, a new neutrophil anti‐microbial mechanism was described, the release of neutrophil extracellular traps (NETs) composed of DNA, histones and anti‐microbial peptides. Several microorganisms, bacterial products, as well as pharmacological stimuli such as PMA, were shown to induce NETs. Neutrophils contain relatively few mitochondria, and derive most of their energy from glycolysis. In this scenario we aimed to analyse some of the metabolic requirements for NET formation. Here it is shown that NETs formation is strictly dependent on glucose and to a lesser extent on glutamine, that Glut‐1, glucose uptake, and glycolysis rate increase upon PMA stimulation, and that NET formation is inhibited by the glycolysis inhibitor, 2‐deoxy‐glucose, and to a lesser extent by the ATP synthase inhibitor oligomycin. Moreover, when neutrophils were exposed to PMA in glucose‐free medium for 3 hr, they lost their characteristic polymorphic nuclei but did not release NETs. However, if glucose (but not pyruvate) was added at this time, NET release took place within minutes, suggesting that NET formation could be metabolically divided into two phases; the first, independent from exogenous glucose (chromatin decondensation) and, the second (NET release), strictly dependent on exogenous glucose and glycolysis.

The Phenotype and Metabolism Relationship of Blood Neutrophils in Patients With Widespread Purulent Peritonitis in the Postoperative Period Dynamics

“…Нейтрофилы являются клетками с неболь-шим количеством митохондрий [21]. В связи с этим, большинство энергозависимых про-цессов реализуется за счет аденозинтрифосфата (АТФ), наработанного в гликолизе [4].…”

“…В связи с этим, большинство энергозависимых про-цессов реализуется за счет аденозинтрифосфата (АТФ), наработанного в гликолизе [4]. Доказано, что при стимуляции функциональной актив-ности нейтрофилов с помощью липополисаха-ридов бактериального происхождения наблю-дается транслокация переносчиков глюкозы на мембрану клеток с последующим повышени-ем интенсивности анаэробного гликолиза [21,23]. Блокирование транспорта глюкозы в клетку приводило к ингибированию функциональной активности нейтрофилов.…”

“…Подобное состояние двух оксидоредуктаз цикла Кребса характеризует субстратный поток высокой интенсивности, что положительно повлияет на активность аэроб-ного дыхания. Необходимо отметить, аэробное дыхание вносит незначительный вклад в общую энергетику нейтрофильных гранулоцитов, од-нако высокая активность дыхательной цепи мо-жет стимулировать вхождение клетки в апоптоз [12,21]. На 24 сутки послеоперационного периода у больных РГП в нейтрофилах крови наблюдает-ся значительное снижение активности НАДН-зависимой реакции МДГ.…”

Reprogramming of metabolism in immune-mediated cells

“…These traps are networks of extracellular fibers composed of DNA, histones and anti-microbial peptides that are able to kill extracellular pathogens and minimize damage to host cells. The formation of NETs is strictly dependent on glucose and to a lesser extent on glutamine, and is also enhanced by the glucose transporter-1 (GLUT-1), glucose uptake, and glycolysis rate under PMA stimulation [3]. NET formation can metabolically be divided into two phases, the first being the chromatin decondensation process, which is independent of exogenous glucose, and the second being NET release, which is strictly dependent on exogenous glucose and glycolysis [3].…”

“…The formation of NETs is strictly dependent on glucose and to a lesser extent on glutamine, and is also enhanced by the glucose transporter-1 (GLUT-1), glucose uptake, and glycolysis rate under PMA stimulation [3]. NET formation can metabolically be divided into two phases, the first being the chromatin decondensation process, which is independent of exogenous glucose, and the second being NET release, which is strictly dependent on exogenous glucose and glycolysis [3]. Interleukin-6 (IL-6) is a potent inducer of energy-dependent NET formation, and hyperglycemia mimics the proinflammatory condition which may lead to a blunted response to external pathogens and susceptibility to infections [4].…”