Effect of MG132, a proteasome inhibitor, on the expression of growth related oncogene protein-alpha in human umbilical vein endothelial cells.
Growth related oncogene protein-alpha (GRO-alpha) is a member of C-X-C chemokine and plays an important role in inflammatory responses. Expression of GRO gene family is regulated by a number of factors at both transcriptional and posttranscriptional levels. In the present study, we have addressed the possible regulation of GRO-alpha expression by ubiquitin-proteasome system. Cultures of human umbilical vein endothelial cells were treated with a proteasome inhibitor, MG132, and the levels of GRO-alpha mRNA were analyzed by reverse transcription-polymerase chain reaction or northern blotting. Levels of GRO-alpha protein in the cell-conditioned medium were determined by enzyme-linked immunosorbent assay. MG132 alone increased the levels of GRO-alpha mRNA and protein; however, it did not affect the GRO-alpha mRNA induced by lipopolysaccharide (LPS) and inhibited the LPS-induced decrease in IkappaB levels. Other proteasome inhibitors, MG115 and lactacystin, also induced the expression of GRO-alpha mRNA. MG132 induced the phosphorylation of p38 MAPK, MEK and JNK. Pretreatment of the cells with SB203580, an inhibitor of p38 MAPK, suppressed the MG132-induced GRO-alpha expression, but pretreatment of the cells with U0126, PD98059 or SP600125, inhibitors of MEK1/2 or JNK, did not influence the effect of MG132. We conclude that MG132 upregulates GRO-alpha expression in vascular endothelial cells, at least in part, through the activation of p38 MAPK.
Shibata
Takeo
T
Department of Vascular Biology, Institute of Brain Science, Hirosaki University School of Medicine, Hirosaki 036-8562, Japan.
Imaizumi
Tadaatsu
T
Matsumiya
Tomoh
T
Tamo
Wakako
W
Hatakeyama
Masaharu
M
Yoshida
Hidemi
H
Munakata
Hirohumi
H
Fukuda
Ikuo
I
Satoh
Kei
K
D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000873:Anthracenes / Q000494:pharmacology; D002478:Cells, Cultured; D054360:Chemokine CXCL1; D019743:Chemokines, CXC / Q000235:genetics / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D020672:I-kappa B Proteins / Q000187:drug effects / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases; D007976:Leupeptins / Q000494:pharmacology*; D048728:MAP Kinase Kinase Kinase 1; D020930:MAP Kinase Kinase Kinases / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism; D016328:NF-kappa B / Q000187:drug effects / Q000378:metabolism; D010766:Phosphorylation; D011725:Pyridines / Q000494:pharmacology; D014471:Umbilical Veins / Q000166:cytology* / Q000187:drug effects; D048051:p38 Mitogen-Activated Protein Kinases
D000873:Anthracenes; C475829:CXCL1 protein, human; D054360:Chemokine CXCL1; D019743:Chemokines, CXC; D015853:Cysteine Proteinase Inhibitors; D004791:Enzyme Inhibitors; D005419:Flavonoids; D020672:I-kappa B Proteins; D007093:Imidazoles; D036341:Intercellular Signaling Peptides and Proteins; D007976:Leupeptins; D016328:NF-kappa B; D011725:Pyridines; C089486:carbobenzoxy-leucyl-leucyl-norvalinal; C067713:lactacystin; C432165:pyrazolanthrone; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048728:MAP Kinase Kinase Kinase 1; D020930:MAP Kinase Kinase Kinases; C482576:MAP3K1 protein, human; C093642:SB 203580; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D000111:Acetylcysteine