Serum and glucocorticoid-regulated kinase 1 regulates neutrophil clearance during inflammation resolution.

Abstract

The inflammatory response is integral to maintaining health by functioning to resist microbial infection and repair tissue damage. Large numbers of neutrophils are recruited to inflammatory sites to neutralize invading bacteria through phagocytosis and the release of proteases and reactive oxygen species into the extracellular environment. Removal of the original inflammatory stimulus must be accompanied by resolution of the inflammatory response, including neutrophil clearance, to prevent inadvertent tissue damage. Neutrophil apoptosis and its temporary inhibition by survival signals provides a target for anti-inflammatory therapeutics, making it essential to better understand this process. GM-CSF, a neutrophil survival factor, causes a significant increase in mRNA levels for the known anti-apoptotic protein serum and glucocorticoid-regulated kinase 1 (SGK1). We have characterized the expression patterns and regulation of SGK family members in human neutrophils and shown that inhibition of SGK activity completely abrogates the antiapoptotic effect of GM-CSF. Using a transgenic zebrafish model, we have disrupted sgk1 gene function and shown this specifically delays inflammation resolution, without altering neutrophil recruitment to inflammatory sites in vivo. These data suggest SGK1 plays a key role in regulating neutrophil survival signaling and thus may prove a valuable therapeutic target for the treatment of inflammatory disease.

• Authors: Joseph Burgon, Anne L Robertson, Pranvera Sadiku, Xingang Wang, Edward Hooper-Greenhill, Lynne R Prince, Paul Walker, Emily E Hoggett, Jonathan R Ward, Stuart N Farrow, William J Zuercher, Philip Jeffrey, Caroline O Savage, Philip W Ingham, Adam F Hurlstone, Moira K B Whyte, Stephen A Renshaw
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 192 Issue 4 Pg. 1796-805 (Feb 15 2014) ISSN: 1550-6606 [Electronic] United States
• PMID: 24431232 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Benzoates
• Bridged Bicyclo Compounds, Heterocyclic
• Immediate-Early Proteins
• Morpholinos
• Phosphoinositide-3 Kinase Inhibitors
• RNA, Messenger
• 2-cyclopentyl-4-(5-phenyl-1H-pyrrolo(2,3-b)pyridin-3-yl)-benzoic acid
• Granulocyte-Macrophage Colony-Stimulating Factor
• Protein Serine-Threonine Kinases
• serum-glucocorticoid regulated kinase

Topics

• Animals
• Animals, Genetically Modified
• Apoptosis (immunology)
• Benzoates (pharmacology)
• Bridged Bicyclo Compounds, Heterocyclic (pharmacology)
• Cell Movement (drug effects)
• Cell Survival (drug effects, immunology)
• Granulocyte-Macrophage Colony-Stimulating Factor (metabolism)
• Humans
• Immediate-Early Proteins (antagonists & inhibitors, genetics, metabolism)
• Inflammation (immunology)
• Morpholinos (genetics)
• Neutrophils (drug effects, immunology)
• Phosphatidylinositol 3-Kinases (drug effects)
• Phosphoinositide-3 Kinase Inhibitors
• Protein Serine-Threonine Kinases (antagonists & inhibitors, genetics, metabolism)
• RNA, Messenger (biosynthesis)
• Zebrafish (genetics)