Human chymase stimulates Ca2+ signaling in human polymorphonuclear cells

• Published in: Immunology letters Vol. 89; no. 2-3; pp. 161 - 165
• Main Authors: Saito, Kayo, Muto, Tsuyoshi, Tomimori, Yoshiaki, Maruoka, Hiroshi, Tanaka, Taisaku, Fukuda, Yoshiaki
• Format: Journal Article
• Language: English
• Published: Netherlands 31.10.2003
• Subjects: Calcium - metabolism; Calcium Signaling - drug effects; Calcium Signaling - physiology; Chymases; Enzyme Inhibitors - pharmacology; Humans; Neutrophils - drug effects; Neutrophils - metabolism; Pertussis Toxin - pharmacology; Serine Endopeptidases - drug effects; Serine Endopeptidases - metabolism
• ISSN: 0165-2478
• DOI: 10.1016/S0165-2478(03)00129-9

Human chymase is known to function as a chemoattractant for human leukocytes. To investigate the mechanism of the chymase-induced cell migration, change in intracellular calcium concentration ([Ca(2+)]i) was examined in human polymorphonuclear (PMN) cells using Fluo-3 as a fluorescent Ca(2+) indicator. Treatment of PMN cells with human chymase caused [Ca(2+)]i elevation in a concentration-dependent manner. Depletion of extracellular Ca(2+) from the medium partially attenuated the chymase-induced [Ca(2+)]i increase, showing that both Ca(2+) influx and Ca(2+) release from internal stores might be involved in the [Ca(2+)]i response. Pretreatment of the cells with pertussis toxin completely blocked the chymase-induced [Ca(2+)]i signal, suggesting an involvement of G protein in the chymase-mediated [Ca(2+)]i elevation. The data in the present study raise the possibility that the chymase-induced cell migration is mediated by the [Ca(2+)]i elevation, which might be caused by stimulation of a G-protein-coupled receptor such as protease-activated receptors (PARs).