2.Recombinant adenovirus overexpressing nkx2.5 protects H9c2 cells against H2O2-induced apoptosis.
Tao LI ; Kesheng JIANG ; Qin RUAN ; Zhiqiang LIU
Chinese Journal of Biotechnology 2012;28(10):1253-1264
To study the function and potential application of nkx2.5, a critical gene for heart development, we constructed a recombinant adenovirus overexpressing nkx2.5 gene (Ad-Nkx2.5) with the AdEasy system. To evaluate the effect and mechanism of Ad-Nkx2.5 against oxidative injury, the H9c2 myocardial cells were infected with the recombinant adenoviruses Ad-Nkx2.5 or Ad-EGFP, and subsequently exposed to H2O2 to induce apoptosis. The anti-apoptotic potential of Ad-Nkx2.5 was validated by MTT assay for cell viability, Hoechst33342 staining for cellular morphology, and immunoblotting for caspase-3 activity. Ad-Nkx2.5 infection led to an increased survival rate of H9c2 cells and decreased the amount of caspase-3 in an active form. Additionally, overexpression of Nkx2.5 inhibited the release of cytochrome C from the mitochondria into the cytosol. Mechanismic studies showed that Nkx2.5 upregulated bcl-2 gene expression and significantly repressed H2O2-induced expression of bax detected by Real-time PCR. Additionally, H2O2 treatment did not affect the nuclear localization of Nkx2.5. These findings indicate that adenovirus-mediated nkx2.5 gene transfer exerted a protective effect on H9c2 cells against H2O2-induced apoptosis via mitochondrial pathway, and the Nkx2.5-mediated expression modulation of apoptosis-associated genes could be involved in this event.
Adenoviridae
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genetics
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metabolism
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Animals
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Apoptosis
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drug effects
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Caspase 3
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metabolism
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Cell Line
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Genetic Vectors
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genetics
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Homeobox Protein Nkx-2.5
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Homeodomain Proteins
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biosynthesis
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genetics
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Hydrogen Peroxide
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pharmacology
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Myocytes, Cardiac
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cytology
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Oxidative Stress
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drug effects
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Proto-Oncogene Proteins c-bcl-2
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metabolism
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Rats
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Recombinant Proteins
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biosynthesis
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genetics
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Transcription Factors
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biosynthesis
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genetics
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bcl-2-Associated X Protein
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metabolism
3.Effect of HIV-1 Nef proteins from a patient with HIV-1-associated dementia on the secretion of TNF-α and IL-1 β cytokines by U87 cells
Dandi LI ; Zeming QIN ; Shuting HE ; Hongling WEN ; Tao HUANG ; Kesheng ZHANG ; Li ZHAO
Chinese Journal of Experimental and Clinical Virology 2021;35(3):241-245
Objective:To investigate the role of HIV-1 negative regulator (Nef) in HIV-1 neuropathogenicity.Methods:Five different HIV-1 nef genes were obtained from the central nervous system (CNS) and peripheral regions (basal ganglia, frontal cortex, meninges, temporal cortex and spleen) of a patient with HIV-1-associated dementia (HAD). The recombinant pcDNA3.1- nef eukaryotic expression vectors were constructed by connecting them with pcDNA3.1 vector and transfected into human glioma cell line U87 respectively. The expression of Nef protein was detected by immunohistochemistry and Western blotting at 22ndhour, 27 th hour, 32nd hour, 37th and 42nd hour after transfection. The result were analyzed quantitatively by JEDA801D and JD-801 software. The supernatant of U87 cells was collected every 5 hours from 27th hour to 62nd hour after transfection. The levels of TNF-α and IL-1 β in the supernatant were determined by ELISA, and the dynamic expression of the two cytokines was analyzed. Results:Five recombinant pcDNA3.1- nef eukaryotic expression vectors of nef genes from different tissues of an HAD patient were successfully constructed and transfected into U87 cells. The result of immunohistochemistry showed that Nef protein began to express at 42nd hour after transfection, which was further confirmed by Western blot. The result of ELISA showed that the levels of cytokines in the supernatant of each group increased gradually with time from 22ed hour to 37th hour after transfection, but there was no significant difference among the groups (TNF-α: F=0.445, P=0.837; F=0.579, P=0.742; F=0.617, P=0.714; F=2.728, P=0.057. IL-1β: F=2.656, P=0.062; F=0.485, P=0.809; F=0.165, P=0.982; F=2.463, P=0.093); The levels of TNF-α and IL-1 β in the experimental group were significantly higher than those in the control group from the 42nd hour ( P<0.05); after 42nd hour, the levels of cytokines in each group gradually decreased, and the levels of TNF-α and IL-1 β remained stable from the 57th hour to the 62nd hour, while the levels of TNF-α and IL-1 β in the experimental group were higher than those in the control group from the 42nd hour to the 62nd hour, the difference was still statistically significant (TNF-α: F=241.310, P<0.001; F=242.638, P<0.001; F=250.114, P<0.001; F=143.877, P<0.001; F=146.172, P<0.001. IL-1β: F=251.578, P<0.001; F=188.816, P<0.001; F=276.240, P<0.001; F=238.136, P<0.001; F=163.361, P<0.001), and there was no significant difference among the experimental groups ( P>0.05). Conclusions:HIV-1 Nef protein can induce and enhance the secretion of TNF-α and IL-1 β in U87 cells. However, the amino acid variation of HIV-1 Nef protein from different sources in an HAD patient had no effect on the secretion of TNF-α and IL-1 β.
4.Preparation and identification of polyclonal antibodies against Moraxella catarrhalis UspA1.
Hui WANG ; Bo YANG ; Kesheng ZHAO ; Jiaji LI ; Xin LI ; Mengmeng KONG ; Chunjie GONG ; Yi WANG ; Ye TAO ; Qiu ZHANG ; Zheng HU
Chinese Journal of Biotechnology 2018;34(1):102-109
To prepare polyclonal antibodies (PcAb) against UspA1 of Moraxella catarrhalis (Mc), we used bioinformatic analysis to determine the surface exposed region in this protein that holds the antigen epitopes. Then the corresponding coding sequences for this fragment was artificially synthesized according to the codon usage of Escherichia coli. The gene fragment was then subcloned into the prokaryotic expression vector pET-28a(+) and expressed in E. coli rosseta (DE3), and then the recombinant UspA1-His proteins were purified. Two New Zealand white rabbits were immunized with this protein to prepare antiserum. The resulting PcAb was then purified from the antiserum with Protein A affinity column. The results of fluorescence antibody assay, enzyme linked immunosorbent assay and Western blotting analysis showed that the PcAb could specifically recognize the surface exposed region of UspA1 on Mc. The preparation of the PcAb laid a foundation of further development of rapid detection technique for M. catarrhalis.