Three transfection reagents, Lipofectamine® 2000, TransIT-PRO® and linear 25 kDa polyethylenimine were evaluated for transient expression of enhanced green fluorescent protein in Chinese hamster ovary ce...Three transfection reagents, Lipofectamine® 2000, TransIT-PRO® and linear 25 kDa polyethylenimine were evaluated for transient expression of enhanced green fluorescent protein in Chinese hamster ovary cells. TransIT-PRO® was found to be more efficient under the examined conditions, but comes at an increased cost compared to the widely used PEI.展开更多
Objective： To observe the effect of matrine on human ether à go-go related gene （HERG） potassium channels expressed in Chinese hamster ovary （CHO） cells and investigate whether HERG channel is a new target o...Objective： To observe the effect of matrine on human ether à go-go related gene （HERG） potassium channels expressed in Chinese hamster ovary （CHO） cells and investigate whether HERG channel is a new target of the pharmacological effect of matrine on arrhythmia and tumor. Methods： HERG channel potassium current in CHO cell was recorded using whole-cell patch-clamp technique, and the influence of matrine on the current was explored. Results： Matrine inhibited HERG potassium current in a dose-dependent manner, and the 50% inhibitory concentration （IC50） was 411±23 μmol/L. Matrine had no significant effect on the activation kinetics, and mainly blocked HERG channels in their closed state. Conclusions： The blocking effect of matrine on HERG channels might be one of the mechanisms against arrythmias and tumors. Unlike most other blockers exerting blocking effect at the intracellular sites by entering the cell with the opening of HERG channel, matrine blocked HERG channels at the extracellular sites.展开更多
Objective To evaluate the cytotoxicity of six commonly used copper-bearing intrauterine devices （Cu-IUDs） on Chinese hamster ovary （CHO-K1） cells and to investigate the influence of frame, shape and copper surface...Objective To evaluate the cytotoxicity of six commonly used copper-bearing intrauterine devices （Cu-IUDs） on Chinese hamster ovary （CHO-K1） cells and to investigate the influence of frame, shape and copper surface area of Cu-IUDs on cell toxicity.Methods Cu-IUDs were incubated in 10% FBS-DMEM/F12 culture medium at 37 ℃ for 24 h. The extracts were analyzed by flame atomic absorption spectrometer and were then diluted into different concentrations with culture medium. Finally, cytotoxicity of these original and diluted extracts on CHO-K1 cells was detected by cell counting kit-8 （CCK-8） assay.Results The viabilities of cells treated with the original extracts of six Cu-IUDs （TCu220C bulb, TCu220C, GCu220, GCu300, Yuangong Cu270 and Yuangong Ⅱ- 300） were all below 10% and the cupric ion concentrations in these extracts were 28.22 mg/L, 31.80 mg/L, 92.80 mg/L, 99.74 mg/L, 114.90 mg/L and 119.20 mg/L, respectively. After these original extracts were diluted, significant differences in cytotoxicity were exhibited. IUDs with larger copper surface areas （GCu300 and Yuangong Ⅱ-300） showed more cytotoxicity than those with smaller areas （GCu220 and Yuangong Cu270） respectively; When different shapes of Cu-IUDs were compared, TCu220C bulb showed lower cytotoxicity than TCu220C, and GCu300 exhibited higher toxicity than Yuangong Ⅱ-300; TCu220C displayed significantly lower cytotoxicity than GCu220 due to their differences in frames.Conclusion We presented evidence on the cytotoxic effects of copper ions released from Cu-IUDs on CHO-K1 cells and found that shape, frame together with copper surface area of Cu-IUDs had obvious influence on the cytotoxicity.展开更多
目的将GPR109A基因插入pEGFP-N3载体中构建重组质粒pEGFP-GPR109A,并建立稳定表达烟酸受体GPR109A的中国仓鼠卵巢(Ch inese ham ster ovary,CHO)细胞株。方法构建重组质粒pEGFP-GPR109A,重组质粒转化大肠杆菌DH5 a,重组质粒经PCR、酶切...目的将GPR109A基因插入pEGFP-N3载体中构建重组质粒pEGFP-GPR109A,并建立稳定表达烟酸受体GPR109A的中国仓鼠卵巢(Ch inese ham ster ovary,CHO)细胞株。方法构建重组质粒pEGFP-GPR109A,重组质粒转化大肠杆菌DH5 a,重组质粒经PCR、酶切、测序验证正确后,应用脂质体转染技术将该质粒导入CHO细胞,用抗生素G418筛选稳定表达的细胞。倒置荧光显微镜观察克隆细胞株荧光信号,RT-PCR检测GPR109A基因mRNA表达,W estern B lotting检测绿色荧光蛋白与烟酸受体GPR109A的融合蛋白(GFP-GPR109A)的表达,激光共聚焦显微镜观察融合蛋白的细胞定位。结果 pEGFP-GPR109A真核表达质粒构建正确,融合蛋白GFP-GPR109A在CHO细胞中稳定表达,表达的融合蛋白主要定位于细胞膜。结论成功构建pEGFP-GPR109A真核表达载体并建立其稳定表达的CHO细胞株;该细胞株的建立有助于GPR109A的更多生理病理功能研究,也为下一步抗动脉粥样硬化的药物筛选奠定了基础。展开更多
Ensuring the removal of host cell proteins(HCPs) during downstream processing of recombinant proteins such as monoclonal antibodies(m Abs) remains a challenge.Since residual HCPs might affect product stability or safe...Ensuring the removal of host cell proteins(HCPs) during downstream processing of recombinant proteins such as monoclonal antibodies(m Abs) remains a challenge.Since residual HCPs might affect product stability or safety,constant monitoring is required to demonstrate their removal to be below the regulatory accepted level of 100 ng/mg.The current standard analytical approach for this procedure is based on ELISA;however,this approach only measures the overall HCP content.Therefore,the use of orthogonal methods,such as liquid chromatography-mass spectrometry(LC-MS),has been established,as it facilitates the quantitation of total HCPs as well as the identification and quantitation of the individual HCPs present.In the present study,a workflow for HCP detection and quantitation using an automated magnetic bead-based sample preparation,in combination with a data-independent acquisition(DIA) LC-MS analysis,was established.Employing the same instrumental setup commonly used for peptide mapping analysis of m Abs allows for its quick and easy implementation into pre-existing workflows,avoiding the need for dedicated instrumentation or personnel.Thereby,quantitation of HCPs over a broad dynamic range was enabled to allow monitoring of problematic HCPs or to track changes upon altered bioprocessing conditions.展开更多
An expressive plasmid pSMTPCH was constructed from porcine growth hormone gene,sheep metallothionein promoter (MT-011)and the vector,pUC19. The linear pSMTPGH and circular pSV2-dhfr were cotransfected into CHO-dhfr ce...An expressive plasmid pSMTPCH was constructed from porcine growth hormone gene,sheep metallothionein promoter (MT-011)and the vector,pUC19. The linear pSMTPGH and circular pSV2-dhfr were cotransfected into CHO-dhfr cell by calcium phosphate coprecipitation. Positive clones made up 74% of total clones, which were identified with ELISA. The expression of pSMTPGH was induced by 0.5 μM of Cd￣++. The clone 1-C-3 was found to secrete hGH at the level of 3800 μg/10￣6 cells/24 hrs in media containing 10 μMTX. After 20 generations in culture, the clone was still stable with hGH expression.The molecular weight of secreted protein was the same as that of the natural pGH, 22KD;the identity was further supported by Western blot.展开更多
文摘Three transfection reagents, Lipofectamine® 2000, TransIT-PRO® and linear 25 kDa polyethylenimine were evaluated for transient expression of enhanced green fluorescent protein in Chinese hamster ovary cells. TransIT-PRO® was found to be more efficient under the examined conditions, but comes at an increased cost compared to the widely used PEI.
基金Supported by Beijing Administration Bureau of Traditional Chinese Medicine (No. JZZ-312)
文摘Objective： To observe the effect of matrine on human ether à go-go related gene （HERG） potassium channels expressed in Chinese hamster ovary （CHO） cells and investigate whether HERG channel is a new target of the pharmacological effect of matrine on arrhythmia and tumor. Methods： HERG channel potassium current in CHO cell was recorded using whole-cell patch-clamp technique, and the influence of matrine on the current was explored. Results： Matrine inhibited HERG potassium current in a dose-dependent manner, and the 50% inhibitory concentration （IC50） was 411±23 μmol/L. Matrine had no significant effect on the activation kinetics, and mainly blocked HERG channels in their closed state. Conclusions： The blocking effect of matrine on HERG channels might be one of the mechanisms against arrythmias and tumors. Unlike most other blockers exerting blocking effect at the intracellular sites by entering the cell with the opening of HERG channel, matrine blocked HERG channels at the extracellular sites.
基金supported by Public Service Platform of Science and Technology Projects in Data mining of contraceptives monitoring and research of risk assessment model(BM2012062)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Objective To evaluate the cytotoxicity of six commonly used copper-bearing intrauterine devices （Cu-IUDs） on Chinese hamster ovary （CHO-K1） cells and to investigate the influence of frame, shape and copper surface area of Cu-IUDs on cell toxicity.Methods Cu-IUDs were incubated in 10% FBS-DMEM/F12 culture medium at 37 ℃ for 24 h. The extracts were analyzed by flame atomic absorption spectrometer and were then diluted into different concentrations with culture medium. Finally, cytotoxicity of these original and diluted extracts on CHO-K1 cells was detected by cell counting kit-8 （CCK-8） assay.Results The viabilities of cells treated with the original extracts of six Cu-IUDs （TCu220C bulb, TCu220C, GCu220, GCu300, Yuangong Cu270 and Yuangong Ⅱ- 300） were all below 10% and the cupric ion concentrations in these extracts were 28.22 mg/L, 31.80 mg/L, 92.80 mg/L, 99.74 mg/L, 114.90 mg/L and 119.20 mg/L, respectively. After these original extracts were diluted, significant differences in cytotoxicity were exhibited. IUDs with larger copper surface areas （GCu300 and Yuangong Ⅱ-300） showed more cytotoxicity than those with smaller areas （GCu220 and Yuangong Cu270） respectively; When different shapes of Cu-IUDs were compared, TCu220C bulb showed lower cytotoxicity than TCu220C, and GCu300 exhibited higher toxicity than Yuangong Ⅱ-300; TCu220C displayed significantly lower cytotoxicity than GCu220 due to their differences in frames.Conclusion We presented evidence on the cytotoxic effects of copper ions released from Cu-IUDs on CHO-K1 cells and found that shape, frame together with copper surface area of Cu-IUDs had obvious influence on the cytotoxicity.
文摘目的将GPR109A基因插入pEGFP-N3载体中构建重组质粒pEGFP-GPR109A,并建立稳定表达烟酸受体GPR109A的中国仓鼠卵巢(Ch inese ham ster ovary,CHO)细胞株。方法构建重组质粒pEGFP-GPR109A,重组质粒转化大肠杆菌DH5 a,重组质粒经PCR、酶切、测序验证正确后,应用脂质体转染技术将该质粒导入CHO细胞,用抗生素G418筛选稳定表达的细胞。倒置荧光显微镜观察克隆细胞株荧光信号,RT-PCR检测GPR109A基因mRNA表达,W estern B lotting检测绿色荧光蛋白与烟酸受体GPR109A的融合蛋白(GFP-GPR109A)的表达,激光共聚焦显微镜观察融合蛋白的细胞定位。结果 pEGFP-GPR109A真核表达质粒构建正确,融合蛋白GFP-GPR109A在CHO细胞中稳定表达,表达的融合蛋白主要定位于细胞膜。结论成功构建pEGFP-GPR109A真核表达载体并建立其稳定表达的CHO细胞株;该细胞株的建立有助于GPR109A的更多生理病理功能研究,也为下一步抗动脉粥样硬化的药物筛选奠定了基础。
基金funding from Thermo Fisher Scientific as part of a funded collaborative agreement with NIBR。
文摘Ensuring the removal of host cell proteins(HCPs) during downstream processing of recombinant proteins such as monoclonal antibodies(m Abs) remains a challenge.Since residual HCPs might affect product stability or safety,constant monitoring is required to demonstrate their removal to be below the regulatory accepted level of 100 ng/mg.The current standard analytical approach for this procedure is based on ELISA;however,this approach only measures the overall HCP content.Therefore,the use of orthogonal methods,such as liquid chromatography-mass spectrometry(LC-MS),has been established,as it facilitates the quantitation of total HCPs as well as the identification and quantitation of the individual HCPs present.In the present study,a workflow for HCP detection and quantitation using an automated magnetic bead-based sample preparation,in combination with a data-independent acquisition(DIA) LC-MS analysis,was established.Employing the same instrumental setup commonly used for peptide mapping analysis of m Abs allows for its quick and easy implementation into pre-existing workflows,avoiding the need for dedicated instrumentation or personnel.Thereby,quantitation of HCPs over a broad dynamic range was enabled to allow monitoring of problematic HCPs or to track changes upon altered bioprocessing conditions.
文摘An expressive plasmid pSMTPCH was constructed from porcine growth hormone gene,sheep metallothionein promoter (MT-011)and the vector,pUC19. The linear pSMTPGH and circular pSV2-dhfr were cotransfected into CHO-dhfr cell by calcium phosphate coprecipitation. Positive clones made up 74% of total clones, which were identified with ELISA. The expression of pSMTPGH was induced by 0.5 μM of Cd￣++. The clone 1-C-3 was found to secrete hGH at the level of 3800 μg/10￣6 cells/24 hrs in media containing 10 μMTX. After 20 generations in culture, the clone was still stable with hGH expression.The molecular weight of secreted protein was the same as that of the natural pGH, 22KD;the identity was further supported by Western blot.
