title: Involvement of protein kinase C in C5a-primed neutrophils for ANCA-mediated activation.
abstract: C5a and the neutrophil C5a receptor play a central role in antineutrophil cytoplasmic antibody (ANCA)-mediated neutrophil recruitment and activation. Our recent study found that activation of p38 mitogen-activated protein kinase (p38MAPK), extracellular signal-regulated kinase (ERK) and phosphoinositol 3-kinase (PI3K) are all important steps in the translocation of ANCA antigens by C5a-mediated priming and activation of neutrophils. The current study further investigated the protein kinase C (PKC) pathway of C5a-mediated neutrophils for ANCA-induced activation. The effect of the PKC inhibitor (bisindolylmaleimide I, BIS) was tested on respiratory burst and degranulation of C5a-primed neutrophils activated with ANCA, as well as on C5a-induced increase in expression of PR3 and MPO. For C5a-primed neutrophils for MPO-ANCA-induced respiratory burst, the mean fluorescence intensity (MFI) value was 369.8±18.8, which decreased to 308.3±14.2 upon pre-incubation with BIS (P<0.001). For PR3-ANCA-positive IgG, the MFI value increased in C5a-primed neutrophils, which decreased upon pre-incubation with BIS. The lactoferrin concentration increased from 414.8±26.9 ng/ml in the non-primed neutrophils supernatant to 1099.8±80.7 ng/ml in C5a-primed neutrophils induced by MPO-ANCA-positive IgG supernatant (P<0.001), and decreased to 814.5±45.3 ng/ml upon pre-incubation with BIS (P<0.01). The lactoferrin concentration also increased in C5a-primed neutrophils induced by PR3-ANCA-positive IgG supernatant and decreased upon pre-incubation with BIS. Membrane expression of PR3 (mPR3) expression increased from 788.0±87.5 in untreated cells to 1071.3±81.3 after C5a treatment and decreased to 827.3±48.1 by BIS (P<0.05). Activation of PKC is an important step in the translocation of ANCA antigens and C5a-induced activation of neutrophils by ANCA.
authors.affiliation: Renal Division, Department of Medicine, Peking University, First Hospital, Peking University Institute of Nephrology, Key Laboratory of Renal Disease, Ministry of Health of China, Key Laboratory of Chronic Kidney Disease Prevention and Treatment Peking University, Ministry of Education, Peking-Tsinghua Center for Life Sciences, Beijing 100034, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Hao
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Zhao
mesh_terms: D019268:Antibodies, Antineutrophil Cytoplasmic / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology*; D015550:Cell Degranulation / Q000187:drug effects / Q000276:immunology; D019069:Cell Respiration / Q000187:drug effects; D002478:Cells, Cultured; D015936:Complement C5a / Q000819:agonists / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects* / Q000276:immunology; D053146:Myeloblastin / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D009504:Neutrophils / Q000276:immunology* / Q000378:metabolism / Q000502:physiology; D009195:Peroxidase / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D021381:Protein Transport / Q000187:drug effects / Q000276:immunology
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D047428:Protein Kinase Inhibitors; D015936:Complement C5a; D009195:Peroxidase; D011493:Protein Kinase C; D053146:Myeloblastin