巨噬细胞特异性敲除KLF2基因小鼠模型构建与鉴定

Construction of macrophage-specific KLF2 gene knockout mice

目的 建立巨噬细胞特异性敲除Kruppel样因子2(kruppel-like factor 2,KLF2)基因小鼠模型,探讨KLF2对巨噬细胞炎症反应的调控作用。方法 运用CRISPR/Cas9基因编辑技术构建KLF2~(flox/+)小鼠。通过与Lyz2-Cre~(+/+)小鼠繁育得到目的基因型小鼠,通过基因型鉴定、实时荧光定量-聚合酶链反应(qRT-PCR)、Western Blot从DNA、RNA、蛋白水平验证KLF2敲除效率。分离培养小鼠骨髓源巨噬细胞(bone marrow-derived macrophages, BMDMs),检测脂多糖(lipopolysaccharide, LPS)诱导的炎症相关因子mRNA变化。结果 建立了KLF2~(flox/flox)/Lyz2-Cre~+基因型小鼠,即巨噬细胞特异性敲除KLF2基因。小鼠骨髓、BMDMs的KLF2 mRNA及蛋白水平显著低于对照组小鼠,而心脏、肝、肾组织中KLF2 mRNA表达较对照组小鼠无显著变化。两组小鼠的体重、进食、进水、形态无显著性差异。在LPS作用下,缺失KLF2的BMDMs炎症相关基因IL-6 mRNA表达水平较对照组显著下降,而IL-1、iNOS、CD86 mRNA表达水平较对照组显著升高。结论 本研究成功构建了巨噬细胞特异性敲除KLF2小鼠模型,为进一步研究巨噬细胞KLF2对临床炎症相关疾病的调控作用及机制奠定基础。

Objective To establish a macrophage-specific KLF2 gene knockout mouse model,and explore the regulatory effect of KLF2 on the macrophage inflammatory response.Methods KLF2 flox/+mice were constructed using CRISPR/Cas9 gene editing technology.Target genotype mice were obtained by breeding with Lyz2-Cre+/+mice and screening genotypes through polymerase chain reaction,and KLF2 knockout efficiency was verified using genotyping,qRT\|PCR,and Western Blot.Bone marrow-derived macrophages(BMDMs)were isolated and cultivated and mRNA levels of inflammation-related factors in lipopolysaccharide-induced BMDMs were detected.Results A KLF2 flox/flox/Lyz2-Cre+mouse model was established.KLF2 mRNA and protein levels in mouse bone marrow and BMDMs were significantly lower in KLF2 knockout mice compared with the findings in control mice,while expression levels of KLF2 in the heart,liver,and kidney showed no significant changes compared with levels in the control group.There were no significant differences in body weight,diet,drinking water,and appearance between the two groups.The group receiving lipopolysaccharide stimulation showed significantly reduced interleukin(IL)-6 mRNA expression and significantly increased IL-1,iNOS,and CD86 mRNA expression in KLF2-deficient BMDMs compared with the control group.Conclusions We constructed a macrophage-specific KLF2 knockout mouse model,thus laying the foundation for further research on the regulatory effect and mechanism of macrophage KLF2 in clinical inflammatory-related diseases.