Exposure to hyperbaric oxygen induces tumour necrosis factor-alpha (TNF-α) secretion from rat macrophages

Abstract

SUMMARYWe investigated the secretion of TNF-a by monocytes and macrophages derived from the peripheral blood, spleen, and lungs after a single exposure to a therapeutic profile of hyperbaric oxygen (HBO). Rats were exposed for 90 min to either 100% oxygen at 0 28 MPa (2-8 atmospheres absolute) or air. Immediately after exposure, mononuclear cells were isolated from blood, spleen, and lungs and cultured for 18h. The secretion of TNF-a from the cultured monocytes/macrophages was determined with and without stimulation with lipopolysaccharide (LPS). Exposure to hyperbaric oxygen induced a significant increase in the spontaneous ex vivo secretion of TNF-a (without LPS) by mononuclear cells from the blood, spleen, and lung (P < 0 05 from air controls). Stimulation with LPS after exposure to HBO induced a significant increase in TNF-a secretion by lung and spleen macrophages compared with air controls (P<005). However, absolute TNF-a levels were not significantly higher than those achieved 'spontaneously' in macrophages exposed to HBO without LPS. Stimulation with LPS induced a marked increase in secretion of TNF-a from blood monocytes after exposure to air, but not after exposure to HBO. These results provide evidence in support of a role played by TNF-a in mediating HBO effects on different tissues and their immune responses.

Effects of hyperoxia exposure on metabolic markers and gene expression in 3T3-L1 adipocytes

“…Hence, Desmarquest et al observed a decrease in several inflammatory markers in alveolar macrophages exposed to hyperoxia [9]. This effect seems to be consistent with hypobaric oxygen therapy (HBOT) studies carried out in ex vivo cell cultures [3,30,54]. These findings are also in agreement with studies demonstrating that HBOT attenuates pro-inflammatory cytokine production of systemic inflammation in animal models [32,57,58].…”

“…In this context, macrophages were isolated from patients with Crohn's disease treated with 90 min of HBOT, secreting less IL-1, IL-6 and TNF- than cells obtained prior to the treatment [54]. Moreover, Lahat et al [30] also observed a decrease in the secretion of TNF- in macrophages of rats exposed to HBOT for 90 min. Furthermore, in a study by Benson et al [3], IL-1 and TNF- synthesis in macrophages was inhibited by a 90-min HBOT exposure.…”

Human Amniotic Fluid Mesenchymal Stem Cells in Combination with Hyperbaric Oxygen Augment Peripheral Nerve Regeneration

“…Several studies showed that monocytemacrophages isolated from HBO-exposed rodents produced fewer pro-inflammatory cytokines than exposed control groups [41,42]. Monocyte-macrophages obtained from patients with Crohn's disease secreted less IL-1, IL-6, and TNF-a in response to LPS when isolated after HBO therapy than cells obtained prior to the treatment [43].…”

Hyperbaric oxygen protects from sepsis mortality via an interleukin-10–dependent mechanism*

“…Although previous studies have evaluated the effect of HBO 2 on macrophage function, these studies have not evaluated the effect of HBO 2 on IL-10 regulation (32)(33)(34). Further, previous studies evaluated the effect of HBO 2 on macrophage cell lines or on primary macrophages derived from healthy HBO 2 -treated animals.…”