Gangliosides activate microglia via protein kinase C and NADPH oxidase.
Microglia, the major immune effector cells in the central nervous system, are activated when the brain suffers injury. A number of studies indicate that gangliosides activate microglia. However, the signaling mechanisms involved in microglial activation are not yet to be elucidated. Our results show that gangliosides induce the expression of interleukin (IL)-1beta, tumor necrosis factor-alpha (TNF-alpha), and inducible nitric oxide synthase (iNOS) in rat brain microglia and BV2 murine microglia via protein kinase C (PKC) and NADPH oxidase. Expression of IL-1beta, TNF-alpha, and iNOS in ganglioside-treated cells was significantly reduced in the presence of inhibitors of PKC (GF109203X, Go6976, Ro31-8220, and rottlerin) and NADPH oxidase (diphenyleneiodonium chloride [DPI]). In response to gangliosides, PKC-alpha, betaII, and delta and NADPH oxidase p67(phox) translocated from the cytosol to the membrane. ROS generation was also activated within 5 min of ganglioside treatment. Ganglioside-induced ROS generation was blocked by PKC inhibitors. Furthermore, ganglioside-induced activation of NF-kappaB, an essential transcription factor that mediates the expression of IL-1beta, TNF-alpha, and iNOS, was reduced in the presence of GF109203X and DPI. Our results collectively suggest that gangliosides activate microglia via PKC and NADPH oxidase, which regulate activation of NF-kappaB.
Min
Kyoung-Jin
KJ
Neuroscience Graduate Program, Ajou University School of Medicine, Suwon, Korea.
Pyo
Han-Kyung
HK
Yang
Myung-Soon
MS
Ji
Kyung-Ae
KA
Jou
Ilo
I
Joe
Eun-Hye
EH
D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D002490:Central Nervous System / Q000166:cytology / Q000201:enzymology*; D004660:Encephalitis / Q000201:enzymology* / Q000503:physiopathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005732:Gangliosides / Q000378:metabolism* / Q000494:pharmacology; D007375:Interleukin-1 / Q000378:metabolism; D007527:Isoenzymes / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D017628:Microglia / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000187:drug effects / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D010750:Phosphoproteins / Q000187:drug effects / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D004791:Enzyme Inhibitors; D005732:Gangliosides; D007375:Interleukin-1; D007527:Isoenzymes; D016328:NF-kappa B; D010750:Phosphoproteins; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; C079789:neutrophil cytosol factor 67K; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C496318:Nos2 protein, rat; D019255:NADPH Oxidases; D011493:Protein Kinase C