Live imaging of chronic inflammation caused by mutation of zebrafish Hai1.

Abstract

The hallmark of chronic inflammation is the infiltration and persistence of leukocytes within inflamed tissue. Here, we describe the first zebrafish chronic inflammation mutant identified in an insertional mutagenesis screen for mutants that exhibit abnormal tissue distribution of neutrophils. We identified a mutant line with an insertion in the Hepatocyte growth factor activator inhibitor 1 gene (hai1; also known as Spint1) that showed accumulation of neutrophils in the fin. The mutant embryos exhibited inflammation in areas of epidermal hyperproliferation that was rescued by knock-down of the type II transmembrane serine protease Matriptase 1 (also known as St14), suggesting a novel role for Hai1-Matriptase 1 pathway in regulating inflammation. Using time-lapse microscopy of mutant embryos that express GFP from a neutrophil-specific promoter, we found that individual neutrophils in inflamed tissue displayed random motility characterized by periods of pausing alternating with periods of motility. During periods of persistent movement the cells were highly polarized, while the pausing modes were characterized by a loss of cell polarity. In contrast to responses to acute injury, neutrophils did not exhibit clear retrograde chemotaxis or resolution of inflammation in the mutant. These findings illustrate the utility of zebrafish as a new model system to study chronic inflammation and to visualize immune responses with high resolution in vivo.

• Authors: Jonathan R Mathias, M Ernest Dodd, Kevin B Walters, Jennifer Rhodes, John P Kanki, A Thomas Look, Anna Huttenlocher
• Journal: Journal of cell science (J Cell Sci) Vol. 120 Issue Pt 19 Pg. 3372-83 (Oct 01 2007) ISSN: 0021-9533 [Print] England
• PMID: 17881499 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Inflammatory Agents, Non-Steroidal
• Nitrobenzenes
• Proteinase Inhibitory Proteins, Secretory
• Sulfonamides
• Zebrafish Proteins
• spint1a protein, zebrafish
• N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide
• Serine Endopeptidases
• matriptase

Topics

• Animals
• Animals, Genetically Modified
• Anti-Inflammatory Agents, Non-Steroidal (pharmacology)
• Cell Movement (drug effects)
• Epithelium (anatomy & histology, physiology)
• Genes, Reporter
• Humans
• In Situ Hybridization
• Inflammation (metabolism, pathology)
• Mutation
• Neutrophils (cytology, drug effects, physiology)
• Nitrobenzenes (pharmacology)
• Phenotype
• Proteinase Inhibitory Proteins, Secretory (genetics, metabolism)
• Serine Endopeptidases (genetics, metabolism)
• Sulfonamides (pharmacology)
• Zebrafish (anatomy & histology, embryology, physiology)
• Zebrafish Proteins (genetics, metabolism)