C5a differentially stimulates the ERK1/2 and p38 MAPK phosphorylation through independent signaling pathways to induced chemotactic migration in RAW264.7 macrophages.
We elucidate the roles of various protein kinases involved in complement 5a (C5a)-induced cell migration. Results showed that extracellular signal-regulated kinase1/2 (ERK1/2), p38 mitogen-activated protein kinase (p38 MAPK) and phosphatidylinositol 3-kinase (P13K) were necessary for C5a-induced migration, whereas protein kinase C and c-Jun N-terminal kinase (JNK) were nonessential. C5a-induced migration was also suppresses by phospholipase C (PLC) inhibitor U73122 and pertussis toxin (PTX). We found that C5a-induced, time-dependent (1) ERK1/2 phosphorylation was markedly diminished by PTX, U73122, P13K inhibitors wortmannin and LY294002 and ERK1/2 inhibitor PD98059; (2) Akt phosphorylation was also attenuated by the above inhibitors except PD98059; (3) p38 MAPK phosphorylation was only affected by PTX. Furthermore, C5a also stimulated PLCbeta(2) membrane translocation in a time-dependent manner that occurred early prior to Akt phosphorylation and could be abolished only by PTX and U73122. These results suggest that C5a, through the activation of PTX-sensitive G protein, to differentially stimulate ERK1/2 and p38 MAPK phosphorylation and evoke cell migration. That is, ERK1/2 but not p38 MAPK phosphorylation is down stream of P13K/Akt and modulated by PLC. Additionally, beta(2) isoform may be one of the participates in C5a signal and acts more upstream of P13K/Akt.
Chiou
Wen-Fei
WF
National Research Institute of Chinese Medicine, 155-1, Li-Nung Street Section 2, Shih-Pai, Taipei 112, Taiwan. wfchiou@cma23.nricm.edu.tw
Tsai
Hwei-Ru
HR
Yang
Li-Ming
LM
Tsai
Wei-Jern
WJ
D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D002633:Chemotaxis; D015936:Complement C5a / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007527:Isoenzymes / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D054799:Phospholipase C beta; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D021381:Protein Transport; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D015398:Signal Transduction; D013997:Time Factors; D010738:Type C Phospholipases / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
D004791:Enzyme Inhibitors; D007527:Isoenzymes; D011518:Proto-Oncogene Proteins; D015936:Complement C5a; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; D010738:Type C Phospholipases; D054799:Phospholipase C beta; C518037:Plcb2 protein, mouse