Neutrophil-induced Endothelial Cell Damage: Inhibition by a 14-Membered Ring Macrolide Through the Action of Nitric Oxide

Abstract

Macrolide antibiotics have been used worldwide for about 40 years. The clinical effectiveness of oral erythromycin for diffuse panbronchiolitis has been established and erythromycin seems to act not only as an antibacterial but also as an anti-inflammatory agent. We investigated the effect of 14-membered ring macrolides, erythromycin and clarithromycin, on human neutrophil functions and endothelial cell damage induced by neutrophils. The superoxide production of neutrophils and Ca²⁺ influx into neutrophils induced by TV-formyl-methionyl-leucyl-phenylalanine was inhibited by treatment with erythromycin but not by treatment with clarithromycin. When endothelial cells were cocultured with neutrophils, nitric oxide (NO) presumably released from endothelial cells were enhanced by treatment with erythromycin but not by treatment with clarithromycin and endothelial cell injury induced by neutrophils was ameliorated by addition of erythromycin but not by clarithromycin. The reduction of neutrophil-induced endothelial cell injury by erythromycin was abolished by treatment with carboxy-PTIO which traps NO in the medium. Moreover, nitrite in the medium in which endothelial cells were incubated with neutrophils was enhanced by treatment with erythromycin and the enhancement of nitrite by erythromycin was partially canceled by addition of H-89, an inhibitor of cyclic AMP-dependent protein kinase (PKA). Erythromycin seems to ameliorate neutrophil-induced endothelial cell injury by affecting not only neutrophil functions but the release of NO from endothelial cells through the action of PKA. The usefulness for the treatment of diseases worsened by the interaction between neutrophils and endothelium might be different among 14-membered ring macrolides.

Mechanisms of Action and Clinical Application of Macrolides as Immunomodulatory Medications

“…Erythromycin stimulates endothelial NOS (eNOS) production by a protein kinase A-dependent mechanism (189). This is believed to inhibit leukocyte adhesion to endothelial cells.…”

“…The effect of macrolides on the calcium response has been observed in other cells. Ca 2ϩ influx into neutrophils and the oxidative burst were inhibited by erythromycin but not clarithromycin, suggesting that effects of macrolides on calcium mobilization are not completely homogenous (189). Recently, roxithromycin was shown to suppress histamine release and prostaglandin D 2 production from human ␤-defensin-2-stimulated mast cells, and this was accompanied by inhibition of the intracellular Ca 2ϩ increase (130).…”

Effect of 14-Membered-Ring Macrolides on Production of Interleukin-8 Mediated by Protease-Activated Receptor 2 in Human Keratinocytes

“…The clinical findings of Tamaki et al correlate with our in vitro results that CAM is not as effective as RXM or EM for inducing the production of IL-8 in NHEK, although the reason for that is unknown. The biological effects of those macrolides seem to not necessarily be coordinated as has been shown for other types of cells (14,17).…”

Effect of azithromycin on natural killer cell function

“…Aside from their anti-bacterial properties, macrolides have potent antiinflammatory activities like decreasing mucus production [3] and inhibiting neutrophil-induced epithelial cell damages [4], decreasing inhibiting cytokine production by T cells [5], inhibiting bacterial biofilm [6], and inducing apoptosis of activated lymphocytes by down-regulating Bcl-xL [7], and blocking the activation of nuclear transcription factors [8].…”