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Abstract Human Embryonic Kidney 293T cells (HEK-293T) are the most common host for viral vector production and are also widely employed for recombinant protein production. These cells are typically cultured in monolayer (adherent culture) using culture medium containing fetal bovine serum (FBS), which impairs batch-to-batch reproducibility and scale-up. The adaptation of adherent cell culture to suspension culture in chemically defined serum-free culture medium is an attractive approach for large-scale bioprocess implementation while aiming for a Good Manufacturing Practice (GMP) compliant production process. Therefore, in the present study, our goal was to adapt HEK-293T cells to serum-free suspension culture conditions and evaluate the feasibility of adapted cells to be transfected using different plasmid vectors for recombinant protein production. Firstly, the cells were efficiently adapted to serum-free conditions by sequential adaptation (FBS-containing medium weaning). During the whole process, parameters such as cell growth, viability and doubling time were evaluated and compared to the control (adherent serum-supplemented HEK-293T cell culture). Afterwards, these cells were adapted to suspension culture by using Erlenmeyer flasks in an orbital shaker platform, being able to achieve meaningful cell density with high viability. Adapted cells presented a transfection efficiency of approximately 50% for all vector constructs used (1054-GFP, Factor-VIII and Factor-IX). Overall, it was possible to successfully adapt HEK-293T cells to suspension and serum-free conditions, which represents an important step towards the development of a scalable and GMP-compliant production process. In addition, adapted cells efficiently expressed the different transgene tested, opening up possibilities for its use in recombinant protein production.
Subject(s)
Recombinant Proteins , Adaptation to Disasters , HEK293 Cells , Culture Media, Serum-FreeABSTRACT
Objective: To construct the RHBDF2 gene over-expression lentivirus vector and to establish the KA. hy926 cells stably expressing RHBDF2, and to provide the evidence for the construction of RHBDF2 gene over-expression lentivirus vector and the establishment of RHBDF2 cells stably expressing RHBDF2. Methods: According to the sequence of RHBDF2 gene provided by NCBI, and the primers were designed and synthesized; the RHBDF2 gene was amplified by PCR method, and the target gene was cloned into the entry vector by Gateway cloning technology, and then subcloned into the lentivirus vector pLV [Exp]-EGFP to construct the recombinant lentivirus plasmid pLV I Exp]-EGFP-RHBDF2; the lentivirus expression vector plasmid pLV I Exp]-EGFP and the recombinant lentivirus plasmid pLV I Exp]-EGFP-RHBDF2 were co-transfected into the HEK293T cells with the virus-assisted packaging plasmids to package the lentivirus and the titer of the lentivirus was detected. The EA. hy926 cells infected with pLV [Exp]-EGFP-control were used as control group and the EA. hy926 cells infected with pLV [Exp]-EGFP-RHBDF2 were used as experiment group. The EA. hy926 cells stably expressing RHBDF2 were screened by puromycin. The fluorescent quantitative PCR (qPCR) and Western blotting methods were used to detect the expression levels of RHBDF2 mRNA and protein in the EA. hy926 cells in control group and experiment group. Results: The enzyme digestion electrophoresis and sequencing results showed that the gene sequence of the EA. hy926 cells over-expression lentivirus vector in experiment group was completely consistent with the designed and synthesized sequence. The lentivirus titer in control group was 1 X 10 TU • mL , and the lentivirus titer in experiment group was 3X 10 TU • mL . The EA. hy926 cells were successfully infected with the lentivirus under fluorescence microscope and the infection efficiency was above 95%. The qPCR detection results showed that the expression level of RHBDF2 mRNA in the EA. hy926 cells in experiment group was higher than that in control group (P'<0.01). The Western blotting results showed that the expression level of RHBDF2 protein in the EA. hy926 cells in experiment group was higher than that in control group ( P < 0. 05 ). Conclusion: The lentivirus vector over-expressing RHBDF2 is successfully constructed∗ and the EA. hy926 cell line stably up-regulating the expression of RHBDF2 is established by using pLV [Exp]-EGFP-RHBDF2 lentivirus.
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Objective To construct a human renal epithelial cell line HEK293T by CRISPR-Cas9-based site-directed knock-in of vascular endothelial growth factor 165 (VEGF165) gene, and avoid the off-target effect caused by lentivirus infection. Methods The VEGF165 expression vector with homologous arm (pUCm-T-VEGF165 plasmid) and the sgRNA expression vector [pSpCas9(BB)-2A-Puro-sgRNA plasmid] were designed and constructed based on the DNA sequence of the EZH2 gene, and then co-transfected into HEK293T cells. The expression of VEGF165 mRNA was detected by qPCR and the expressions of VEGF165 proteins were detected by Western Blot. Results The qPCR and Western Blot results showed that, comparing with the control, the pUCm-T-VEGF165 plasmid and pSpCas9(BB)-2A-Puro-sgRNA plasmid, the expression of the co-transfection plasmid were significantly increased, i.e. 3.42±0.30 vs. 1.02±0.21, 1.13±0.16 and 0.98±0.18 for the VEGF165 mRNA level (all P<0.01), and 1.13±0.16 vs. 1.02±0.06, 0.88±0.03 and 0.80±0.05 for the VEGF165 protein level (all P<0.01), respectively. Besides, the expression of EZH2 was significantly down-regulated, i.e. 0.14±0.06 vs. 1.08±0.11, 1.02±0.12 and 1.13±0.16 for the EZH2 mRNA level (all P<0.01), and 0.23±0.03 vs. 1.05±0.13, 0.91±0.04 and 0.81±0.06 for the EZH2 protein level (all P<0.01), respectively. This result showed that the VEGF165 was successfully inserted into the EZH2 genome, interfering the EZH2 expression. Conclusions VEGF165 gene can be successfully knocked into HEK293T cells by CRISPR/Cas9 system.
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Objective: To construct the miR-186 overexpression lentiviral vector and package the lentivirus, and to explore the infection efficiency and the expression level of miR-186 in the HEK293T cells. Methods: The Hsa-miR-186 precursor sequence was used as a template to design and synthesize the primer, and the the pre-miR-186 gene was amplified by PCR. The pre-miR-186 gene sequence was cloned into the lentiviral vector FV040 carrying EGFP/Puromycin cassette. The recombinant lentiviral vector was digested by EcoR I and Age I restriction endonuclease and confirmed by sequencing. The recombinant FV040 Vector and FV040 miR-186 were co-transfected into the HEK293T cells with the helper plasmids using Lipofectamine 2000, respectively; the FV040 Vector lentivirus (control group) and the FV040 miR-186 lentivirus (experiment group) were collected and used to infect the HEK293T cells 48 h after transfection, respectively. The green fluorescence distribution in the HEK 293T cells was observed 48 h after transfection, and the expression level of miR-186 was determined by real-time fluorescence quantitative PCR. Results: The sequencing analysis results indicated that the sequence of miR-186 overexpressing lentivirus was identical with the sequence of miR-186 published on GenBank. The titers in control group and experiment group were 6×108 TU · mL-1 and 5 × 108 TU · mL-1, respectively. The relative expression level of miR-186 in the HEK293T cells in experiment group (12. 640 0 ± 0. 788 4) was significantly increased by 15. 07 times (t=14. 72, P<0. 01) compared with control group (0. 838 7 ± 0. 145 6). Conclusion: The lentiviral vector which overexpresses miR-186 is constructed successfully and the miR-186 lentivirus is prepared. The HEK 293T cells are infected with miR-186 lentivirus successfully and the expression level of miR-186 in the HEK 293T cells is increased significantly.
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Aim: To establish a HEK-293T cell line model stably expressing TRPA1 channel, and to verify the successful establishment of the model. Methods: The eukaryotic expression plasmid of TRPA1 was constructed and transfected into HEK-293T cells by liposome transfection method, the stable expression strain was screened by G418, and the transcription and protein expression of TRPA1 gene in HEK-293T cells were detected by RT-PCR and immunohistochemical techniques. Results: After restriction enzyme digestion and sequencing, it proved recombinant cloning plasmid of TRPA1 gene was successfully constructed; the results of PCR and immunohistochemistry showed that this recombinant plasmid could be transferred into HEK-293T cells with TRPA1 gene stable expression. Conclusions: A HEK-293T cell line with stable expression of TRPA1 channel is successfully constructed, which lays the foundation for studying the physiological and pathological functions of TRPA1 in vitro and screening of relevant TR-PA1 channel regulators.
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OBJECTIVE@#To investigate the role of Cyr61 in angiotensin Ⅱ (AngⅡ)-induced functional changes in HEK293 cells and explore the mechanism.@*METHODS@#Cyr61 knockdown in cultured HEK293T cells was achieved by transfection of the cells with CRISPR/Cas9 KO plasmid. The changes in apoptosis and expression levels of Cyr61 and Bcl-2 in the cells with or without Cyr61 knockdown in response to treatment with 10 mol/L AngⅡ for 48 h were analyzed using flow cytometry, qRT-PCR and Western blotting.@*RESULTS@#The cells with Cyr61 knockdown showed significantly decreased expression of Cyr61 protein as compared with the control cells ( < 0.05). AngⅡ treatment for 48 h significantly increased the expression of Cyr61 and lowers the expression of Bcl-2 at both the protein and mRNA levels in HEK293T cells. In HEK293T cells with Cyr61 knockdown, AngⅡ treatment resulted in significantly increased expression of Bcl-2 in HEK293T cells as compared with that of the control group ( < 0.05). AngⅡ treatment caused significantly increased apoptotic rate in HEK293T cells as compared with the cells with Cyr61 knockdown [(26.94 ± 3.73)% (3.87 ± 0.83)%, < 0.05), and the apoptosis rate was significantly lowered to (15.76 ± 1.31)% in HEK293T cells with Cyr61 knockdown following AngⅡ treatment ( < 0.05).@*CONCLUSIONS@#The up-regulation of Cyr61 expression is related with AngⅡ-induced injury in HEK293T cells, and down-regulating Cyr61 expression can effectively protect HEK293T cells against AngⅡ-induced injury.
Subject(s)
Humans , Angiotensin II , Apoptosis , Cysteine-Rich Protein 61 , HEK293 Cells , Up-RegulationABSTRACT
OBJECTIVE@#To establish a stable HEK293T cell line with c.392G>T (p.131G>V) mutation site knockout in gene using CRISPR/Cas9 technique.@*METHODS@#We designed 4 pairs of small guide RNA (sgRNA) for c.392G>T(p.131G>V) mutation site, and constructed exogenous PX458 plasmids expressing Cas9-sgRNA. The plasmids were transfected into HEK293T cells, and the cells expressing GFP fluorescent protein were separated by flow cytometry for further culture. After verification of the knockout efficiency using T7 endonuclease Ⅰ, the monoclonal cells were screened by limiting dilution and DNA sequencing to confirm the knockout. We detected the expressions of mRNA and protein and examined functional changes of the genetically modified cells.@*RESULTS@#We successfully constructed the Cas9-sgRNA exogenous PX458 plasmid based on the c.392G>T(p.131G>V) mutation site of gene. The editing efficiency of the 4 pairs of sgRNA, as detected by T7E1 enzyme digestion, was 6.74%, 12.36%, 12.54% and 2.94%. Sanger sequencing confirmed that the HEK293T cell line with stable knockout of c.392G>T(p.131G>V) was successfully constructed. The genetically modified cells expressed lower levels of mRNA and protein and showed reduced enzyme activity and proliferative capacity and increased apoptosis in response to vitamin K3 treatment.@*CONCLUSIONS@#We successfully constructed a stable HEK293T cell model with gene c.392G>T(p.131G>V) mutation site knockout to facilitate future study of gene repair.
Subject(s)
Humans , CRISPR-Cas Systems , HEK293 Cells , Mutation , PlasmidsABSTRACT
Objective To investigate the effects of dihydropteridine reductase (QDPR) on regulating apoptosis induced by plamitic acid(PA). Methods The transfection of HEK293T cells experiment was divided into 3 groups. A group was the control vector group. B group was the control vector group induced by PA. C group was the recombinant plasmid QDPR group induced by PA. First, control vector and recombinant plasmid QDPR was respectively transfected into HEK293T cells. After 24 h, PA with concentration of 0. 5 mmol/L was added into the medium of above cells. The cells of control vector group, the cells of control vector group induced by PA and the cells of recombinant plasmid QDPR group induced by PA were cultured for another 24 hours. At last, cells were harvested to detect tetrahydrobiopterin (BH4) and reactive oxygen species(ROS) generation, Beclin 1, Caspase 3 and Beclin 2 expression. Results ① After transfection, the recombinant plasmid QDPR was successfully constructed and expressed in cells.② There was no significant difference between A group and B group in BH4 generation. Compared with B group, BH4 generation increased in C group (P < 0. 05).③ ROS generation was increased in B group compared with A group, and decreased ROS generation in C group compared with B group (P < 0. 05).④ Western blot analysis revealed that Beclin 1 and Caspase 3 increased (P < 0. 05 ) while Beclin 2 decreased in B group compared with A group (P < 0. 05). Compared to B group, Beclin 1 and Caspase 3 decreased while Beclin 2 increased in C group (P < 0. 05 ). Conclusion QDPR may regulate apoptosis induced by fatty acids by decreasing the generation of ROS and increasing the level of BH4 and the expression of Beclin 2 associated with anti-apoptosis.
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Hydrogen peroxide (H2O2) and free radicals cause oxidative stress, which induces cellular injuries, metabolic dysfunction, and even cell death in various clinical abnormalities. Fullerene (C60) is critical for scavenging oxygen free radicals originated from cell metabolism, and reduced glutathione (GSH) is another important endogenous antioxidant. In this study, a novel water-soluble reduced glutathione fullerene derivative (C60-GSH) was successfully synthesized, and its beneficial roles in protecting against H2O2-induced oxidative stress and apoptosis in cultured HEK 293T cells were investigated. Fourier Transform infrared spectroscopy and (1)H nuclear magnetic resonance were used to confirm the chemical structure of C60-GSH. Our results demonstrated that C60-GSH prevented the reactive oxygen species (ROS)-mediated cell damage. Additionally, C60-GSH pretreatment significantly attenuated H2O2-induced superoxide dismutase (SOD) consumption and malondialdehyde (MDA) elevation. Furthermore, C60-GSH inhibited intracellular calcium mobilization, and subsequent cell apoptosis via bcl-2/bax-caspase-3 signaling pathway induced by H2O2 stimulation in HEK 293T cells. Importantly, these protective effects of C60-GSH were superior to those of GSH. In conclusion, these results suggested that C60-GSH has potential to protect against H2O2-induced cell apoptosis by scavenging free radicals and maintaining intracellular calcium homeostasis without evident toxicity.
Subject(s)
Humans , Antioxidants , Pharmacology , Apoptosis , Calcium , Metabolism , Caspase 3 , Genetics , Metabolism , Cell Survival , Fullerenes , Chemistry , Pharmacology , Gene Expression Regulation , Glutathione , Pharmacology , HEK293 Cells , Hydrogen Peroxide , Pharmacology , Ion Transport , Malondialdehyde , Metabolism , Oxidative Stress , Proto-Oncogene Proteins c-bcl-2 , Genetics , Metabolism , Reactive Oxygen Species , Metabolism , Signal Transduction , Superoxide Dismutase , Metabolism , bcl-2-Associated X Protein , Genetics , MetabolismABSTRACT
Aim The TRPV1 plasmid was transiently transfected into human embryonic kidney HEK 293T cells to establish the heterologous expression system of TRPV1-channel. Methods The transfection efficiency was confirmed under fluorescence mi-croscope and the TRPV1 protein expression was identified by u-sing Western blot, and the functional characteristics of the chan-nel were studied by using the method of confocal microscopy. Results The transfection rate could reach 40% ~50%; the transfected cells were found to have a clear band at the corre-sponding position that TRPV1 should be, which indicated that TRPV1 channel protein was expressed in the transfected cells. The confocal microscopy imaging result showed that the trans-fected HEK 293T cells were activated by TRPV1 channel ago-nist. Conclusion Transient transfection of HEK 293T cells with TRPV1 channel is successfully constructed and the heterol-ogous TRPV1 channel is verified to have normal calcium-media-ting function.
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Objective: To establish a HEK-293T cell model with sodium channel function similar to that in PRKAG2 syndrome. Methods: Vectors ofPRKAG2 gene and SCN5A gene were constructed and were used to co-transfect HEK-293T cells. Immunofluorescence, real-time PCR and Western blotting analysis were used to examine the transfection results and the expression of interested mRNA and protein. Results: Imunofluorescence findings showed red fluorescence and green fluorescence in HEK-293T cells 48 hours after co-transfection. Real-time PCR and Western blotting analysis showed SCN5A expression in pure SCN5A group, SCN5A + wild-type group, SCN5A + R302Q mutant group, and SCN5A + G100S mutant group, but not in the blank control group, showing significant significance (P<0.05). Expression of PRKAG2 gene and protein in SCN5A+PRKAG2 group was significantly higher than those in the blank control group, pure SCN5A group, SCN5A+R302Q, and SCN5A+G100S groups (P<0.05). Conclusion: We have successfully established a HEK-293T cell model with sodium channel function similar to that in PRKAG2 syndrome, paving a way for future study.
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This study investigated the conjoined cellular oxidative damage of human embryo kidney 293T (HEK293T) cells induced by cadmium chloride (CdCl2) and nanometer titanium dioxide (nano-TiO2).RT-PCR technique was used to detect the expressions of Heme oxygenase-1(HO-1) and 8-oxoguanine DNA glycosylase (OGG1).The activities of superoxide dismutase (SOD) and catalase enzyme (CAT) and concentrations of reactive oxygen species (ROS) and maldondialdehyde (MDA)were measured by different approaches.The results showed that CdCl2 and nano-TiO2 at a low concentration of 0.75 total toxic unit (TU) exerted an additive effects on HO-1 gene expression,CAT activities and MDA concentrations.When the total TU was increased to 1 or 1.25 TU,the interaction was synergetic.Moreover,the mixture with high proportion of CdCl2 produced an additive effect on the OGG1gene expression,and the interaction was changed to be synergetic when the concentration of CdCl2 was lower than or equal to that of nano-TiO2.Synergetic effects of CdCl2 and nano-TiO2 on cellular oxidative damage of HEK293T cells were found as indicated by the changes in the SOD activities and ROS concentrations.It was concluded that CdCl2 and nano-TiO2 exerts synergistic effects on the cellular oxidative damage of HEK293T cells,and the sensitivity of these indicators of oxidative damage varies with the proportion of CdCl2 and nano-TiO2 in the mixture.
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This study investigated the conjoined cellular oxidative damage of human embryo kidney 293T (HEK293T) cells induced by cadmium chloride (CdCl2) and nanometer titanium dioxide (nano-TiO2).RT-PCR technique was used to detect the expressions of Heme oxygenase-1(HO-1) and 8-oxoguanine DNA glycosylase (OGG1).The activities of superoxide dismutase (SOD) and catalase enzyme (CAT) and concentrations of reactive oxygen species (ROS) and maldondialdehyde (MDA)were measured by different approaches.The results showed that CdCl2 and nano-TiO2 at a low concentration of 0.75 total toxic unit (TU) exerted an additive effects on HO-1 gene expression,CAT activities and MDA concentrations.When the total TU was increased to 1 or 1.25 TU,the interaction was synergetic.Moreover,the mixture with high proportion of CdCl2 produced an additive effect on the OGG1gene expression,and the interaction was changed to be synergetic when the concentration of CdCl2 was lower than or equal to that of nano-TiO2.Synergetic effects of CdCl2 and nano-TiO2 on cellular oxidative damage of HEK293T cells were found as indicated by the changes in the SOD activities and ROS concentrations.It was concluded that CdCl2 and nano-TiO2 exerts synergistic effects on the cellular oxidative damage of HEK293T cells,and the sensitivity of these indicators of oxidative damage varies with the proportion of CdCl2 and nano-TiO2 in the mixture.