南方医科大学学报 ›› 2021, Vol. 41 ›› Issue (1): 116-122.doi: 10.12122/j.issn.1673-4254.2021.01.17

• • 上一篇    下一篇

gsdmd基因敲除巨噬细胞RAW 264.7的构建:基于CRISPR/Cas9 系统

周丽婷,叶 颖,原海波,吴超逸,吴淑燕   


  • 出版日期:2021-01-26 发布日期:2021-01-26

Construction of macrophage RAW 264.7 cells with gsdmd gene knockout by CRISPR/Cas9 system

  • Online:2021-01-26 Published:2021-01-26

摘要:

目的 利用CRISPR/Cas9系统构建gsdmd基因敲除的巨噬细胞RAW 264.7,为研究gasdermin D(GSDMD)在巨噬细胞中的生物学功能提供细胞模型。方法 针对gsdmd基因靶向设计4条向导RNA(sgRNA),构建pGL3-sgRNA串联载体后PCR、测序鉴定,将Cas9质粒和pGL3-sgRNA串联载体分两步电转至巨噬细胞RAW 264.7;qPCR检测cas9的表达;嘌呤霉素筛选出阳性单克隆后PCR、Western blot和测序鉴定。将鼠伤寒沙门菌与gsdmd-/-RAW 264.7细胞共培养,Annexin Ⅴ/PI染色及比色法检测乳酸脱氢酶(LDH)释放水平分析细胞死亡情况。结果 qPCR结果表明获得稳定表达cas9的RAW 264.7-Cas9细胞(P<0.01);PCR 及测序证明 pGL3-sgRNA 串联载体构建成功;PCR、测序及 Western blot 结果表明成功构建 gsdmd-/- RAW 264.7 细胞。Annexin Ⅴ/PI染色及LDH释放水平发现敲除gsdmd可降低巨噬细胞死亡率(P<0.01)。结论 本研究利用CRISPR/Cas9系统成功构建gsdmd-/-RAW 264.7细胞,为后续深入研究GSDMD介导的巨噬细胞死亡及其机制奠定基础。

关键词:

Abstract:

Objective To construct a cell model of gsdmd gene knockout in macrophage RAW 264.7 cells using CRISPR/Cas9 system. Methods Four specific single guide RNAs (sgRNAs) targeting gsdmd were designed to construct pGL3-sgRNA recombinant plasmids, which were identified by PCR amplification and sequencing. Cas9 and the recombinant plasmids were transfected into RAW 264.7 cells in two steps, and the cellular expression of cas9 was detected with real-time quantitative PCR (qPCR). The positive cell clones with gsdmd gene knockout were screened using puromycin and verified by sequencing and Western blotting. Annexin Ⅴ/PI staining and LDH release assay were performed in gsdmd-/- RAW 264.7 cells after beingco-cultured with Salmonella Typhimurium. Results qPCR results showed that cas9 gene was stably expressed in RAW 264.7-Cas9 cells (P<0.01). PCR and sequencing results demonstrated successful construction of the recombinant plasmid pGL3-sgRNA. The results of PCR, sequencing and Western blotting all confirmed that gsdmd-/- RAW 264.7 cells were successfully constructed. Annexin Ⅴ/PI staining and LDH release assay showed that gsdmd gene knockout significantly inhibited macrophage death caused by S. Typhimurium infection (P<0.01). Conclusion gsdmd-/- RAW 264.7 cells provide a cell model for studying the mechanisms underlying GSDMD-mediated macrophage death.

Key words: