Inhibitory effect of 30-kDa phytoglycoprotein on expression of TNF-alpha and COX-2 via activation of PKCalpha and ERK 1/2 in LPS-stimulated RAW 264.7 cells.
A 30-kDa DBD glycoprotein, which consists of carbohydrate content (61%) and protein content (39%), is a naturally occurring phytoglycoprotein found in Dioscorea batatas Decne (DBD). In the present study, we investigated the anti-inflammatory potentials of the DBD glycoprotein on lipopolysaccharide (LPS, 2 microg/ml)-induced pro-inflammatory signal transduction cascade in murine macrophage cell line (RAW 264.7 cells). Our results showed that the DBD glycoprotein significantly inhibits the translocation of protein kinase C alpha (PKCalpha) to membrane and the phosphorylation of extracellular signal-regulated kinase (ERK) in LPS-stimulated RAW 264.7 cells. We also found that the DBD glycoprotein (200 microg/ml) has suppressive effects on the DNA binding activities of nuclear factor-kappa B (NF-kappaB), on the expression of p50, p65, tumor necrosis factor (TNF)-alpha, and cyclooxygenase (COX)-2, and on the production of superoxide anion radical [see text] in LPS-stimulated RAW 264.7 cells. Interestingly, the expression of TNF-alpha and COX-2 was significantly blocked by treatment with PKC inhibitor (Staurosporine) as well as ERK1/2 inhibitors (PD98059). Collectively, we assume that the DBD glycoprotein has anti-inflammatory potential, which can modulate pro-inflammatory signal transduction cascade in LPS-stimulated RAW 264.7 cells.
Lee
Sei-Jung
SJ
Molecular Biochemistry Laboratory, Biotechnology Research Institute and Center for the Control of Animal Hazards Using Biotechnology (BK 21), Chonnam National University, 300 Yongbong-Dong, Kwang-ju, 500-757, South Korea.
Lim
Kye-Taek
KT
D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D027742:Dioscorea / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D006023:Glycoproteins / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D008970:Molecular Weight; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D010940:Plant Proteins / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D051571:Protein Kinase C-alpha / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D013481:Superoxides / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D006023:Glycoproteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; D010940:Plant Proteins; D014409:Tumor Necrosis Factor-alpha; D013481:Superoxides; D004247:DNA; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; D051571:Protein Kinase C-alpha; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3