Hydrogen Sulfide Augments Neutrophil Migration through Enhancement of Adhesion Molecule Expression and Prevention of CXCR2 Internalization: Role of ATP-Sensitive Potassium Channels

Abstract

In this study, we have addressed the role of H2S in modulating neutrophil migration in either innate (LPS-challenged naive mice) or adaptive (methylated BSA (mBSA)-challenged immunized mice) immune responses. Treatment of mice with H2S synthesis inhibitors, dl-propargylglycine (PAG) or β-cyanoalanine, reduced neutrophil migration induced by LPS or methylated BSA (mBSA) into the peritoneal cavity and by mBSA into the femur/tibial joint of immunized mice. This effect was associated with decreased leukocyte rolling, adhesion, and P-selectin and ICAM-1 expression on endothelium. Predictably, treatment of animals with the H2S donors, NaHS or Lawesson’s reagent, enhanced these parameters. Moreover, the NaHS enhancement of neutrophil migration was not observed in ICAM-1-deficient mice. Neither PAG nor NaHS treatment changed LPS-induced CD18 expression on neutrophils, nor did the LPS- and mBSA-induced release of neutrophil chemoattractant mediators TNF-α, keratinocyte-derived chemokine, and LTB4. Furthermore, in vitro MIP-2-induced neutrophil chemotaxis was inhibited by PAG and enhanced by NaHS treatments. Accordingly, MIP-2-induced CXCR2 internalization was enhanced by PAG and inhibited by NaHS treatments. Moreover, NaHS prevented MIP-2-induced CXCR2 desensitization. The PAG and NaHS effects correlated, respectively, with the enhancement and inhibition of MIP-2-induced G protein-coupled receptor kinase 2 expression. The effects of NaHS on neutrophil migration both in vivo and in vitro, together with CXCR2 internalization and G protein-coupled receptor kinase 2 expression were prevented by the ATP-sensitive potassium (KATP+) channel blocker, glybenclamide. Conversely, diazoxide, a KATP+ channel opener, increased neutrophil migration in vivo. Together, our data suggest that during the inflammatory response, H2S augments neutrophil adhesion and locomotion, by a mechanism dependent on KATP+ channels.

IMMUNOHISTOCHEMICAL APPROACH REVEALS LOCALIZATION OF CYSTATHIONINE-?-LYASE AND CYSTATHIONINE-ß-SYNTHETASE IN ETHANOL-INDUCED GASTRIC MUCOSA DAMAGE IN MICE

“…Hydrogen sulfide (H 2 S) is a gaseous transmitter involved in a multitude of physiologic functions, which includes immune and inflammatory processes (2) , perception, and pain mediation, as well as control of gastric mucosal integrity, vascular tone, and the control of gastrointestinal motility (4) . H 2 S is synthesized endogenously from L-cysteine, primarily via two enzymes: cystathionine-γ-lyase (CSE) and cystathionine-β-synthetase (CBS) (9) .…”

Uncoupling Protein-2 Negatively Regulates Polymorphonuclear Leukocytes Chemotaxis via Modulating [Ca 2+ ] Influx

“…16,29 Although whether PMN contain the same type of K ATP channel as pancreatic ␤ cells is not clear, there is well-established evidence that ATP-sensitive potassium channels play a critical role in modulating PMN inflammatory responses, including the enhanced expression of adhesion molecules and cell migration. 38,39 The molecular basis underlying the alteration of UCP2 level in PMN during chemotaxis process remains elusive. However, we speculate that 2 possible mechanisms may be involved in this process.…”

Histamine H2 Receptor Signaling in the Pathogenesis of Sepsis: Studies in a Murine Diabetes Model

“…Immunofluorescence was used to analyze GRK2 expression on blood neutrophils at 6 h postsurgery using anti-mouse GRK2 (Y137; Abcam) as the primary Ab, as previously described (14). Cell nuclei were stained with DAPI.…”

“…We and others have shown that the severity of sepsis in nondiabetic mice and patients is associated with reduced neutrophil migration to the focus of infection. This reduction in neutrophil migration is due to the internalization of the chemokine receptor CXCR2 and modulation of adhesion molecules expression on endothelium (13)(14)(15). CXCR2 internalization is associated with upregulation of G protein-coupled receptor kinase 2 (GRK2) expression in circulating neutrophils, which is, at least partially, mediated by systemic TLR2 and TLR4 activation (16)(17)(18).…”