Construction of interferon alpha/beta receptor subunit 1 gene knockout Caco-2 cell line based on CRISPR/Cas9 system / 中国生物制品学杂志

@#Objective To knockout interferon alpha/beta receptor subunit 1(IFNAR1) gene in human colorectal adenocarcinoma cells Caco-2 using clustered regularly interspaced short palinmic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)system to construct IFNAR1 knockout Caco-2 cell line.Methods The single guide RNA(sgRNA)sequence was designed to specifically recognize the exon region of IFNAR1 gene using CRISPR/Cas9 technology,and the LentiCRISPRv2-IFNAR1-sgRNA recombinant plasmid was constructed.Caco-2 cells were infected with the plasmid packaged by lentivirus and screened by puromycin resistance.The obtained monoclonal cell lines were cultured by limited dilution method,which were verified for the effect of IFNAR1 gene knockout by target gene sequencing and Western blot,and detected for the mRNA levels of CXC chemokine ligand 10(CXCL10)and interferon-stimulatd gene 20(ISG20)in IFNAR1knockout cells by adding exogenous IFNβ.Results Sequencing results of plasmid LentiCRISPRv2-IFNAR1-sgRNA showed that the insertion sites were all located at the sticky end of BsmBⅠenzyme digestion.Two IFNAR1 knockout monoclonal cell lines were obtained.The sequencing results showed that Caco-2-IFNAR1-KO1 had 5 bp deletion in the sixth exon of IFNAR1,and Caco-2-IFNAR1-KO2 had 18 bp deletion and 1 bp insertion in the seventh exon.Compared with wild-type Caco-2 cells,Caco-2-IFNAR1-KO1 and Caco-2-IFNAR1-KO2 cells showed no expression of IFNAR1 protein.Compared with no IFNβ stimulation,the mRNA levels of CXCL10 gene(t = 0.566 and 1.268 respectively,P>0.05)and ISG20 gene(t =1.522 and 1.733 respectively,P>0.05)in Caco-2-IFNAR1-KO1 and Caco-2-IFNAR1-KO2 cells stimulated by 50 ng/mL IFNβ showed no significant increase.While compared with those of wild-type Caco-2 cells,the mRNA levels of CXCL10gene(t = 6.763 and 6.777 respectively,P<0.05)and ISG20 gene(t = 5.664 and 5.65 respectively,P<0.05)in Caco-2-IFNAR1-KO1 and Caco-2-IFNAR1-KO2 cells decreased significantly under the stimulation of 50 ng/mL exogenous IFNβ.Conclusion Caco-2 cell line with IFNAR1 knockout was successfully constructed by using CRISPR/Cas9 technology,and the downstream molecules activated by IFNAR(interferon alpha/beta receptor)in this cell line were obviously inhibited,which provided a powerful tool for further exploration of the innate immune response and replication packaging mechanism of Caco-2 cells after virus infection.

Preparation of Zoledronate liposome and its impact on apoptosis of Kupffer cells in rat liver

Abstract Purpose: To establish a method for the preparation of zoledronate liposome and to observe its effect on inducing the apoptosis of rat liver Kupffer cells. Methods: Zoledronate was encapsulated in liposomes, and then the entrapment rate was detected on a spectrophotometer. The prepared Zoledronate liposome (0.01 mg/mL) was injected into the tail vein of SD rats. Three days later, the number of Kupffer cells (CD68 positive) in rat liver tissue was detected by immunohistochemistry. Flow cytometry was used to detect the apoptosis rate of the isolated liver Kupffer cell cultured in vitro. Results: The entrapment rate of Zoledronate was 43.4±7.8%. Immunohistochemistry revealed that the number of Kupffer cells was 19.3±2.1 in PBS group and 5.5±1.7 in Zoledronate liposome group, with a significant difference (P<0.05). The apoptosis rate of Kupffer cells was 4.1±0.8% in PBS group, while it was 9±2.2% and 23.3±5.9% in Zoledronate liposomes groups with different concentrations of Zoledronate liposome (P<0.05). Conclusions: Zoledronate liposomes can effectively induce the apoptosis of Kupffer cells in vivo and in vitro, and the apoptosis rate is related to the concentration of Zoledronate liposome. To establish a rat liver Kupffer cell apoptosis model can provide a new means for further study on Kupffer cell function.

Establishment of circulating tumor cell lines / 国际肿瘤学杂志

The specificity of circulating tumor cell (CTC) such as epithelial-mesenchymal transition,fusion of bone marrow-derived cells,resistance anoikis determines the necessity of cell cultivating.The produced cell lines can provide good material basis for further research of malignant tumor metastasis,also provide individualized targeted therapy for patients with a new direction.