M-CSF induces monocyte survival by activating NF-κB p65 phosphorylation at Ser276 via protein kinase C.
Macrophage colony-stimulating factor (M-CSF) promotes mononuclear phagocyte survival and proliferation. The transcription factor Nuclear Factor-kappaB (NF-κB) is a key regulator of genes involved in M-CSF-induced mononuclear phagocyte survival and this study focused at identifying the mechanism of NF-κB transcriptional activation. Here, we demonstrate that M-CSF stimulated NF-κB transcriptional activity in human monocyte-derived macrophages (MDMs) and the murine macrophage cell line RAW 264.7. The general protein kinase C (PKC) inhibitor Ro-31-8220, the conventional PKCα/β inhibitor Gö-6976, overexpression of dominant negative PKCα constructs and PKCα siRNA reduced NF-κB activity in response to M-CSF. Interestingly, Ro-31-8220 reduced Ser276 phosphorylation of NF-κBp65 leading to decreased M-CSF-induced monocyte survival. In this report, we identify conventional PKCs, including PKCα as important upstream kinases for M-CSF-induced NF-κB transcriptional activation, NF-κB-regulated gene expression, NF-κB p65 Ser276 phosphorylation, and macrophage survival. Lastly, we find that NF-κB p65 Ser276 plays an important role in basal and M-CSF-stimulated NF-κB activation in human mononuclear phagocytes.
Department of Internal Medicine, The Ohio State University, Columbus, Ohio, USA.
Yijie
Y
Wang
Xiaokui
X
Mo
Melissa G
MG
Piper
Hongmei
H
Wang
Narasimham L
NL
Parinandi
Denis
D
Guttridge
Clay B
CB
Marsh
D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000502:physiology*; D024202:Electrophoretic Mobility Shift Assay; D007211:Indoles / Q000494:pharmacology; D016173:Macrophage Colony-Stimulating Factor / Q000502:physiology*; D051379:Mice; D009000:Monocytes / Q000166:cytology*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D060888:Real-Time Polymerase Chain Reaction; D012694:Serine / Q000378:metabolism*; D051996:Transcription Factor RelA / Q000737:chemistry / Q000378:metabolism*
D007211:Indoles; D047428:Protein Kinase Inhibitors; C498144:Rela protein, mouse; D051996:Transcription Factor RelA; D012694:Serine; D016173:Macrophage Colony-Stimulating Factor; D011493:Protein Kinase C; C064758:Ro 31-8220