The dengue virus envelope protein induced PAI-1 gene expression via MEK/ERK pathways.
Dengue virus (DV) infections cause mild dengue fever or severe life-threatening dengue haemorrhagic fever (DHF)/ dengue shock syndrome (DSS). DV-infected patients have high plasma concentrations of plasminogen activator inhibitor type I (PAI-1). However, the mechanism to cause haemorrhage in DV infections remains poorly understood. In this study, investigation was carried out on the purified recombinant domain III of the envelope glycoprotein of DV serotypes 2 (EIII) and the signalling pathways of EIII leading to PAI-1 gene expression were measured by RT-PCR, Western blot, and immunofluorescence stain. Reporter gene constructs containing serially 5'-deleted sequences of the proximal human PAI-1 promoter region were constructed and then transfected to Huh7 cells, a human hepatoma cell line, prior to EIII treatment. EIII increased the PAI-1 mRNA and protein levels in a dose-dependent manner in Huh7 cells. Results showed that U0126, an inhibitor of extracellular signal-regulated kinase (ERK) kinase (MEK), almost completely suppressed EIII-induced PAI-1 expression. The results suggest that the MEK/ERK signalling pathways mediate the EIII-dependent induction of PAI-1 gene expression via the proximal promoter region.
Shyu
Huey-Wen
HW
Department of Medical Technology, Fooyin University, Kaohsiung Hsien, Taiwan. shyuhw@hotmail.com
Lin
Yi-Ying
YY
Chen
Lien-Cheng
LC
Wang
Yi-Fen
YF
Yeh
Trai-Ming
TM
Su
Shu-Jem
SJ
Cheng
Wei-Cheng
WC
Chen
Chang-Yu
CY
Lin
Kuan-Hua
KH
Chou
Miao-Chen
MC
D001777:Blood Coagulation; D015153:Blotting, Western; D002070:Butadienes / Q000494:pharmacology; D045744:Cell Line, Tumor; D048049:Extracellular Signal-Regulated MAP Kinases; D005455:Fluorescent Antibody Technique; D006801:Humans; D020930:MAP Kinase Kinase Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D009570:Nitriles / Q000494:pharmacology; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014162:Transfection; D015854:Up-Regulation; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism*
D002070:Butadienes; C051821:E-glycoprotein, Dengue virus type 2; D009570:Nitriles; D017395:Plasminogen Activator Inhibitor 1; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger; C051321:SERPINE1 protein, human; D018808:Transcription Factor AP-1; C113580:U 0126; D014759:Viral Envelope Proteins; D048049:Extracellular Signal-Regulated MAP Kinases; D020930:MAP Kinase Kinase Kinases