OBJECTIVETo investigate the effect of cytomegalovirus infection on expression of matrix metalloproteinase-2 in human endothelial cells.

METHODSHuman umbilical vein endothelial cells were cultured in vitro. Cells between 3-6 passages were infected with cytomegalovirus for different time. Expression of matrix metalloproteinase-2 mRNA was analyzed by reverse transcription-polymerase chain reaction, matrix metalloproteinase-2 activity was detected by gel zymography.

RESULTSExpression of matrix metalloproteinase-2 mRNA and its activity 6 hours after infection was almost equal to control, and was greatly enhanced 12 and 24 hours after infection.

CONCLUSIONCytomegalovirus infection up-regulates expression of matrix metalloproteinase-2 in human endothelial cells. It might be one of the mechanisms that cytomegalovirus is involved in atherosclerosis.

Cells, Cultured ; Cytomegalovirus ; physiology ; Endothelial Cells ; cytology ; metabolism ; virology ; Gene Expression Regulation, Enzymologic ; Host-Pathogen Interactions ; Humans ; Matrix Metalloproteinase 2 ; biosynthesis ; genetics ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Umbilical Veins ; cytology

The highly virulent PRRSV isolate strain HN-1/06 was cultivated on Marc-145. To study the viral entry mechanisms, the GP5 gene of PRRSV isolate was amplified by RT-PCR and cloned into pcDNA3.0 to generate the expressing plasmid pcDNA-GP5. pcDNA-GP5 was transfected into 293T by the calcium phosphate precipitation method. Analysis of flow cytometry confirmed that the GP5 proteins were expressed in surface of the 293T cells. Then 293T cells were transfected with pcDNA-GP5, pHIT60 and pHIT111 plasmids to generate pseudotyping virus. The pseudotyping virus supernatant was harvested 48 hours post-transfection and was detected by Western blotting and infection assay. Western blotting indicated that the GP5 glycoproteins were incorporated into the retroviral pseudotyped virus. Infection assay showed that the pseudotyped virus infected 293T and Mark-145 cell. The pseudotyped virus could be used to further study infectious mechanism of PRRSV.
Animals ; Cell Line ; Cloning, Molecular ; Endothelial Cells ; cytology ; metabolism ; virology ; Leukemia Virus, Murine ; genetics ; metabolism ; Mice ; Porcine respiratory and reproductive syndrome virus ; chemistry ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; Swine ; Transfection ; Viral Envelope Proteins ; biosynthesis ; genetics ; Virion ; genetics ; metabolism

OBJECTIVETo investigate the mechanisms for the cytopathic effect (CPE) of human cytomegalovirus (HCMV) in ECV304 endothelial-like cells.

METHODSPCR and indirect immunofluorescence were used to detect HCMV infection by examining immediate-early (IE) gene and protein expression of the virus in ECV304 cells. Phase-contrast and electron microscopies were performed to observe the morphological changes of the infected and uninfected cells, and DNA ladder analysis and flow cytometry were carried out to study HCMV-induced cell apoptosis.

RESULTSIn HCMV-infected ECV304 cells, cytopathic effects were first observed at approximately 72 h post-infection. The cells with CPE changes exhibited detachment from the monolayer, cell rounding and shrinkage. The expression of the IE gene was detected. Chromatin condensation and nuclear fragmentation along with dramatic changes of the mitochondria were observed by electron microscopy at 96 h post-infection. Cellular DNA fragmentation was observed in the infected cells, which had cells apoptotic rates of 4.1% and 45.7% at 96 h and 144 h post-infection, respectively.

CONCLUSIONHCMV can induce apoptosis of ECV304 endothelial-like cells.

Antigens, Viral ; genetics ; metabolism ; Apoptosis ; physiology ; Cell Line ; Cytomegalovirus ; genetics ; growth & development ; metabolism ; DNA, Viral ; analysis ; Endothelial Cells ; cytology ; ultrastructure ; virology ; Fluorescent Antibody Technique, Indirect ; Humans ; Immediate-Early Proteins ; genetics ; metabolism ; Microscopy, Electron ; Microscopy, Phase-Contrast ; Polymerase Chain Reaction ; Umbilical Veins ; cytology ; virology

The regulation mechanism of interferon (IFN) and IFN-stimulated genes is a very complex procedure and is dependent on cell types and virus species. We observed molecular changes related to anti-viral responses in endothelial cells during Hantaan virus (HTNV) infection. We found that there are two patterns of gene expression, the first pattern of gene expression being characterized by early induction and short action, as in that of type I IFNs,' and the other being characterized by delayed induction and long duration, as those of IRF-7, MxA, and TAP-1/2. Even though there are significant differences in their induction folds, we found that all of IFN-alpha/beta , IRF- 3/7, MxA, and TAP-1/2 mRNA expressions reached the peak when the viral replication was most active, which took place 3 days of post infection (d.p.i.). In addition, an interesting phenomenon was observed; only one gene was highly expressed in paired genes such as IFN-alpha/beta??(3/277-folds), IRF-3/7 (2.2/29.4-folds), and TAP- 1/2 (26.2/6.1-folds). Therefore, IFN-beta, IRF-7, and TAP-1 seem to be more important for the anti-viral response in HTNV infection. MxA was increased to 296-folds at 3 d.p.i. and kept continuing 207-folds until 7 d.p.i.. The above results indicate that IFN-beta works for an early anti-viral response, while IRF7, MxA, and TAP-1 work for prolonged anti-viral response in HTNV infection.
ATP-Binding Cassette Transporters/*genetics ; Blotting, Western ; Cells, Cultured ; Endothelial Cells/metabolism/*virology ; GTP-Binding Proteins/*genetics ; *Gene Expression Regulation ; Hantaan virus/*immunology ; Histocompatibility Antigens Class I/analysis ; Humans ; Interferon Regulatory Factor-3/genetics ; Interferon Regulatory Factor-7/*genetics ; Interferons/*genetics ; RNA, Messenger/analysis