Site-specific integration and stable expression of exogenous protein at a novel site on CHO cell chromosome / 中国药科大学学报

@#Finding stable expression sites on the chromosomes of Chinese hamster ovary (CHO) cells is an effective method to solve the problem of unstable expression of CHO cells in long-term culture. Our group used lentiviral transfection to integrate the tracer gene (Zsgreen1) into the chromosome of CHO cells and found multiple potential stable expression sites. This study verified the ability of one of the sites located in the 148052-148157 bp region on chromosome NW_003614241.1 to stably express exogenous proteins.The expression of Zsgreen1 gene was first observed, and CRISPR/Cas9 technology was then used to integrate the enhanced green fluorescent protein (EGFP) gene into this site. Three strains of EGFP gene integrated cells were obtained. After 60 generations of suspension culture, the fluorescence intensity of the cells had no significant changes, which proved that this site can stably express the EGFP gene. The same method was used to construct recombinant CHO cell lines expressing the human serum albumin (HSA) gene, and was verified by Western blot that this site could express and secrete HSA. It shows that the above-mentioned sites can be integrated and can stably express exogenous proteins.

Anti-liver fibrosis activities of the extracellular domain of transforming growth factor beta type II receptor fusion protein in vivo / 中国药科大学学报

@#This study is performed to analyze the anti-liver fibrosis effect of the fusion protein of human serum albumin and extracellular domain of transforming growth factor beta type II receptor(eTGFBR2)in vivo to looking for the more stable anti-liver fibrosis drug. The mice model of liver fibrosis was constructed by CCl4 induction and the following groups are included in the study: the control group, CCl4 model group, the positive control group, eTGFBR2 treatment group, HSA-eTGFBR2 treatment group, and HSA group. Hematoxylin eosin staining, serum liver function index detection, and western blot are used to identify the anti-liver fibrosis activities. The results showed that: (1)CCl4 caused liver structure disorder, hepatocellular necrosis, collagen fibers proliferation, and induced liver fibrosis at last; (2)HSA-eTGFBR2 and its monomer drug improved the symptoms of liver fibrosis significantly, as well as reduced the damage of liver cells and collagen deposition, and recovered the liver basic structure to normal. Both of HSA-eTGFBR2 and its monomer drug improved liver function and reduced the expression level of liver fibrosis marker α-SMA and COL I. Moreover, the anti-liver fibrosis effect of the fusion protein is comparable to the monomer drug. In contrast, the albumin had no effect on therapeutic effect; (3)Reducing the injection frequency of HSA-eTGFBR2 achieved the comparable effects to the monomer drug with the normal injection frequency. In summary, the fusion protein HSA-eTGFBR2 has good anti-liver fibrosis effect. In addition, reducing the injection frequency of the fusion protein could also achieve the comparable treatment with the monomer drug, indicating that the fusion protein is stable and has longer half-lives and then a relatively positive application prospect in future.

Anti-liver fibrosis activities of human insulin-like growth factor-1 in vitro / 中国药科大学学报

This study was focus on investigating the anti-liver fibrosis effects of insulin-like growth factor-1 (IGF-1) in vitro.The effects of IGF-1 on human liver L-02 cell viability and cell cycle were observed.CC14-induced L-02 cell injury was set up to detect the anti-apoptotic activity of insulin-like growth factor-1 (IGF-1).Transforming growth factor β1 (TGF-β1) induced hepatic stellate cell line (HSC-T6) were used as a liver fibrosis model in vitro to analyze the effects of IGF-1 on the expression of liver fibrosis proteins and intracellular TGF-β1/Smad signaling pathway in HSC-T6 cells.The results showed that IGF-1 could relieve the growth inhibition effects of TGF-β1 on L-02 cells,increase the viability of L-02 cells injured by CCl4,decrease the expression of liver fibrosis proteins,and inhibit the TGF-β1/Smad signaling pathway by inhibiting the phosphorylation of Smad3.Our study suggested that IGF-1 exerted anti-liver fibrosis effects by stimulating L-02 cells proliferation,reducing cell damage and inhibiting ECM accumulation via interfering TGF-β1/Smad signaling pathway.

High salt diet enhances the physical coupling between TRPV4 and cPLA2 / 中国药理学通报

Aim To observe the physical coupling between transient receptor potential channel vanilloid type 4 (TRPV4 ) and cPLA2 in endothelial cells. Methods We investigated the physical association of TRPV4-cPLA2 coupling by immunofluorescence reso-nance energy transfer (immuno-FRET)to assess the spatial proximity between TRPV4 and cPLA2 in human microvascular endothelial cells (HMEC),primary cul-tured endothelial cells and in thoracic aortas rings from high salt-induced hypertension mice.Results At the cellular level,with high salt treatment,the physical in-teraction of TRPV4 and cPLA2 was significantly en-hanced in primary vascular endothelial cells and HMEC.Furthermore, in thoracic aortas rings from high salt-induced hypertension mice,we found an in-creases interaction between TRPV4 and cPLA2 in en-dothelial cells from arterial segments .Conclusion High-salt treatment increases the endothelial TRPV4-cPLA2 coupling,indicating that this coupling may pro-vide a new target for vascular endothelial dysfunction.

Research advances of recombinant coagulation factor VII expression and synthesizing mechanism / 中国药科大学学报

Haemophilia is caused by lack of coagulation factor VIII or IX in patients′blood with inadequate hemostasis.Currently recombinant coagulation factor VII(rFVII)produced in different cells is used against clini-cal bleeding of haemophilia patients.To enhance the production and activity of rFVII;some eukaryotic cells such as baby hamster kidney(BHK);Chinese hamster ovary(CHO);insect cell and fish embryo;were used to express rFVII.Meanwhile;the effect of functional gene on the activity of rFVII and the limitation of rFVII production caused by post-translational modification were investigated by different methods.The role of rFVII in hemostasis;synthesis of rFVII in different eukaryotic cells and impact on production of post-translational modification are reviewed in this article.