BACKGROUNDTo establish a sandwich ELISA method for detection of reporter chloramphenicol acetyltransferase (CAT) gene.

METHODSThe full length sequence of CAT gene was amplified with PCR using plasmid pBLCAT6 as template, and inserted into the prokaryotic expression plasmid Pgex-2T. The purified fusion protein was emulsified with complete or incomplete Freund adjuvant and injected subcutaneously into rabbits. The antibody was labeled with biotin, and a sandwich ELISA technique with biotin streptavidin amplify system was established. Several CAT reporter plasmids containing different HPV 16 LCR sequences were generated and transfected transiently to monolayer cells in vitro. The cytoplasm proteins were extracted and the expressions of CAT were evaluated with the newly established ELISA assay.

RESULTSSDS-PAGE displayed that the molecular weight of the expressed fusion protein was about 54,000. The prepared antiserum was able to recognize the CAT protein expressed by mammalian cells or prokaryote cells. Under the control of different promoters and their regulate sequences,two to eight folds CAT expression increased were evaluated in transiently transfected mammalian cells by the newly established sandwich ELISA method.

CONCLUSIONSThe established method could sensitively reflect the activities of the upstream promoters, as well as the influence of exchanges of nucleotides within the regulate region on the promoter activities. Therefore, it proposes a convenient assay for the studies using CAT as the reporter gene.

Animals ; Antibodies ; analysis ; Cells, Cultured ; Chloramphenicol O-Acetyltransferase ; analysis ; genetics ; immunology ; Enzyme-Linked Immunosorbent Assay ; methods ; Genes, Reporter ; Male ; Papillomaviridae ; genetics ; Plasmids ; genetics ; Rabbits ; Recombinant Fusion Proteins ; analysis ; biosynthesis ; immunology

OBJECTIVETo analyze the upstream region of radiation-induced junB gene.

METHODSFour plasmids containing 250 bp, 590 bp, 900 bp and 1650 bp, and CAT reporter gene were constructed separately and introduced to L8704 cells. The cells were irradiated with 2 Gy X-rays and incubated at different intervals. Total RNA was extracted from the cells and fluctuation of the CAT mRNA level was assessed by the RNA ratio of CAT/beta-actin measured by quantitative Northern blot hybridization.

RESULTSCAT mRNA expression containing 900 bp and 1560 bp junB promoter remarkably and rapidly increased, and reached its peak 30 min after 2 Gy X-ray irradiation.

CONCLUSIONS590-900 bp fragments located in the upstream region of junB gene play an important role in the early process of cells against radiation.

Actins ; analysis ; metabolism ; Animals ; Blotting, Northern ; Cells, Cultured ; Chloramphenicol O-Acetyltransferase ; genetics ; Gene Expression Regulation ; radiation effects ; Genes, Reporter ; Genes, jun ; genetics ; radiation effects ; In Situ Hybridization ; Mice ; Mice, Inbred BALB C ; Plasmids ; analysis ; genetics ; RNA ; isolation & purification ; metabolism ; RNA, Messenger ; analysis ; metabolism ; Time Factors ; X-Rays

OBJECTIVETo analyze the transcription activation and possible regulation mechanism of human X-box binding protein 1(XBP1)gene 5'upstream DNA sequence in different cell lines.

METHODSSix kinds of XBP1 promoter deletion mutants were cloned into pGEM-Teasy vector, which included XBP1 gene 5' upstream -1039 to 66 bp,-859 to 66 bp,-623 to 66 bp,-351 to 66 bp,-227 to 66 bp,-227 to -45 bp respectively. Every deletion mutant sequence was cut from Teasy-XBP1p by KpnI and Xho I, and subcloned into pCAT3-Basic to produce a set of constructs termed as p1-XBP1p, p2-XBP1p, p3-XBP1p, p4-XBP1p, p5-XBP1p, p6-XBP1p, respectively. The transcription activity of each construct was detected after transiently transfecting K562, HepG2,NIH-3T3 and L0(2)cell with FuGENE 6 transfection reagent. Cells transfected by pCAT3-Basic or pCAT3-Promoter were used as negative and positive controls. The activity of chloramphenicol acetyltransferase(CAT), which reflects the transcription activation of the XBP1 gene promoter, was detected by ELISA after 48 hours of transfection.

RESULTSThe reporter vectors of six kinds of XBP1 promoter deletion mutants were successfully constructed, as confirmed by restriction enzyme digestion and sequencing. The activities of p4-XBP1p and p5-XBP1p were higher than the other deletion mutants in K562 and HepG2. And the activity of p5-XBP1p was the highest in HepG2. There was no activity detected from any transfected NIH-3T3.

CONCLUSIONThe XBP1 gene promoter can transactivate its downstream gene to transcription. The core sequence of XBP1 promoter was implied between -227 bp and 66 bp. This sequence was connected with the transcriptional activity of XBP1 promoter closely. Its transcription activity varies with different cell lines. XBP1 promoter might drive gene expression with cell-type specificity.

3T3 Cells ; 5' Flanking Region ; genetics ; Animals ; Base Sequence ; Cell Line ; Chloramphenicol O-Acetyltransferase ; metabolism ; DNA ; analysis ; DNA-Binding Proteins ; genetics ; Gene Deletion ; Gene Expression Regulation ; physiology ; Genes, Reporter ; Humans ; K562 Cells ; Mice ; Molecular Sequence Data ; Nuclear Proteins ; genetics ; Promoter Regions, Genetic ; genetics ; Regulatory Factor X Transcription Factors ; Transcription Factors ; Transcription, Genetic ; physiology ; Transcriptional Activation ; Transfection ; Tumor Cells, Cultured ; X-Box Binding Protein 1

Direct injection of the vascular endothelial growth factor (VEGF) gene plasmid DNA into the myocardium was shown to induce development of new blood vessels to increase the circulation in the heart of patients with coronary artery diseases. However, such angiogenic gene therapy (via naked DNA) was limited by low level of gene expression. Furthermore, the temporal and spatial characteristics of VEGF gene transfer in the heart are not known. In this study, we demonstrated that a plasmid vector, containing the human cytomegalovirus immediate early (HCMV IE) promoter and enhancer, induces greater expression of gene in the rat heart monitored by gene fused to the chloramphenicol acetyl transferase (CAT) reporter, than four different viral and cellular promoters. Interestingly, expression of VEGF121 protein showed an earlier peak, a shorter duration, and a wider distribution than that of CAT only. Therefore, a plasmid vector with an HCMV IE promoter/enhancer provides clear advantages over other previously developed plasmids. Furthermore, expression profile of VEGF121 gene may provide useful information in the design of angiogenic gene therapy in the heart
Animals ; Chloramphenicol O-Acetyltransferase/analysis/genetics ; Comparative Study ; Cytomegalovirus/*genetics ; DNA, Viral/*administration & dosage/*genetics ; Endothelial Growth Factors/analysis/*genetics ; *Enhancer Elements (Genetics) ; Gene Expression Regulation, Viral ; Gene Fusion ; *Gene Transfer Techniques ; Genes, Viral ; Genetic Vectors ; Intercellular Signaling Peptides and Proteins/analysis/*genetics ; Lymphokines/analysis/*genetics ; Male ; Myocardium/*metabolism ; Plasmids/genetics ; *Promoter Regions (Genetics) ; Rats ; Rats, Sprague-Dawley ; Time Factors ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factors

Direct injection of the vascular endothelial growth factor (VEGF) gene plasmid DNA into the myocardium was shown to induce development of new blood vessels to increase the circulation in the heart of patients with coronary artery diseases. However, such angiogenic gene therapy (via naked DNA) was limited by low level of gene expression. Furthermore, the temporal and spatial characteristics of VEGF gene transfer in the heart are not known. In this study, we demonstrated that a plasmid vector, containing the human cytomegalovirus immediate early (HCMV IE) promoter and enhancer, induces greater expression of gene in the rat heart monitored by gene fused to the chloramphenicol acetyl transferase (CAT) reporter, than four different viral and cellular promoters. Interestingly, expression of VEGF121 protein showed an earlier peak, a shorter duration, and a wider distribution than that of CAT only. Therefore, a plasmid vector with an HCMV IE promoter/enhancer provides clear advantages over other previously developed plasmids. Furthermore, expression profile of VEGF121 gene may provide useful information in the design of angiogenic gene therapy in the heart
Animals ; Chloramphenicol O-Acetyltransferase/analysis/genetics ; Comparative Study ; Cytomegalovirus/*genetics ; DNA, Viral/*administration & dosage/*genetics ; Endothelial Growth Factors/analysis/*genetics ; *Enhancer Elements (Genetics) ; Gene Expression Regulation, Viral ; Gene Fusion ; *Gene Transfer Techniques ; Genes, Viral ; Genetic Vectors ; Intercellular Signaling Peptides and Proteins/analysis/*genetics ; Lymphokines/analysis/*genetics ; Male ; Myocardium/*metabolism ; Plasmids/genetics ; *Promoter Regions (Genetics) ; Rats ; Rats, Sprague-Dawley ; Time Factors ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factors

OBJECTIVETo screen the 5' regulatory region of the aldose reductase (AR) gene for genetic variabilities causing changes in protein expression and affecting the promoter function.

METHODSThe screenings were carried out by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). All SSCP variants were submitted for DNA sequencing and inserted into the plasmid chloromycetin acetyl transferase (CAT) enhancer vector. The constructs were used to transfect Hela cells, and CAT assays were performed to assess promoter activity. Gel mobility shift and footprinting assays were also performed to determine the interaction between the DNA and nuclear proteins.

RESULTSTwo polymorphisms, C (-106) T and C (-12) G, were identified in the regulatory region in 123 Chinese control subjects and 145 patients with type 2 diabetes mellitus. The frequencies of genotypes WT/WT, WT/C (-12) G and WT/C (-106) T were not significantly different between the subjects and patients. In the patients with and without retinopathy, frequencies of WT/C (-106) T were 31.5% and 17.5% (P < 0.05) respectively, and the frequencies of WT/C (-12) G were 10.5% and 2.5% (P > 0.05) respectively. The total frequency of WT/C (-12) G and WT/C (-106) T in patients with retinopathy was 41.8%, significantly higher than that (20.0%) in patients without retinopathy (P < 0.025). The relative transcription activities of the wild-type, the C (-12) G and the C (-106) T were 15.7%, 31.0% and 32.2%, respectively. The results of DNA-protein interaction assays showed that these variations did not change the binding site of DNA with trans-acting factors.

CONCLUSIONThe polymorphisms C (-12) G and C (-106) T strongly associated with diabetic retinopathy in the Chinese population have been identified in the regulatory region of the aldose reductase gene.

5' Flanking Region ; genetics ; Adult ; Aldehyde Reductase ; genetics ; metabolism ; Binding Sites ; genetics ; China ; Chloramphenicol O-Acetyltransferase ; genetics ; metabolism ; DNA ; chemistry ; genetics ; DNA Footprinting ; Diabetes Mellitus, Type 2 ; enzymology ; genetics ; Electrophoretic Mobility Shift Assay ; Female ; HeLa Cells ; Humans ; Male ; Middle Aged ; Mutation ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Polymorphism, Single-Stranded Conformational ; Recombinant Fusion Proteins ; genetics ; metabolism ; Regulatory Sequences, Nucleic Acid ; genetics ; Sequence Analysis, DNA ; Transcription, Genetic