- 作者: Lee-Wei Chen; Min-Wai Lin & Ching-Mei Hsu
- 作者服務機構: a Department of Surgery, Kaohsiung Veterans General Hospital, National Yang-Ming Medical University, Taipei;; b Department of Biological Sciences, National Sun Yat-Sen University, 70 Lien-Hai Road, Kaohsiung, Taiwan
- 中文摘要: --
- 英文摘要: The signaling pathways leading to extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) activation by N-formyl-Met-Leu-Phe (fMLP) or platelet activating factor (PAF) in human neutrophils were examined. Previously, we found that changes of intracellular Ca2+ ([Ca2+]i) stimulated by PAF and fMLP were due to Ca2+ influx and internal Ca2+ release, respectively. To further determine the mechanism of MAPK activation and its relation with Ca2+ influx, blood from healthy human volunteers was taken by venous puncture. Human polymorphonuclear cells (PMNs) were isolated and incubated with protein kinase C (PKC) inhibitor Calphostin C, PKC-γ isoform inhibitor GF109203X, phosphatidylmositol 3-kinase (PI3K) inhibitors wortmannin and LY294002, phospholipase C (PLC) inhibitor U73122, phospholipase A2 (PLA2) inhibitor Aristolochic acid, store-operated calcium (SOC) channel inhibitor SKF96365, or extracellular calcium chelator EGTA followed by fMLP or PAF treatment. Phosphorylation of ERK p38 was determined by immunoblotting analysis. Our data indicate that neutrophil MAPK signaling pathways mediated by fMLP and PAF are different. PAF-induced ERK phosphorylation is mediated by PI3K, PKC, PLA2, PLC, and extracellular calcium, whereas fMLP-induced ERK phosphorylation does not involve the PKC-γ isoform and extracellular calcium. PAF-induced p38 phosphorylation involves PLA2, whereas fMLP-induced p38 activation is PLC dependent.
- 中文關鍵字: --
- 英文關鍵字: fMLP, MAPK, PAF, PI3K, PKC, PLA2, PLC, SOC