烧伤小鼠IFIT1表达的初步观察

IFIT1 expression in burned mice

目的 观察烧伤小鼠干扰素诱导表达蛋白IFIT1的表达变化，初步探究其表达变化的原因。方法 实验小鼠致TBSA 15％Ⅱ度烧伤，1d及7d后处死，取肝、肺及脾组织。脂多糖掺入小鼠腹腔巨噬细胞株RAW264．7的培养基中，至终浓度0．1～1．0μg/ml，作用6h。提取组织及细胞RNA，进行半定量逆转录-聚合酶链式反应，提取组织及细胞裂解上清，进行免疫印迹检测。结果 小鼠肝、肺、脾组织IFIT1的转录在烧伤后1d升高，伤后7d恢复至伤前水平；肝、肺、脾IFIT1的蛋白水平在伤后1d一致升高，伤后7d仍能检出升高。体外实验，细菌脂多糖显著激活RAW264．7细胞的IFIT1转录及蛋白表达。结论 烧伤小鼠伤后早期IFIT1表达迅速升高，此变化与同期的内毒素血症引起的细胞应激有关。

Objective To investigate the expression of interferon-induced protein with tetratricopeptide repeats 1 （IFIT1） in burned mice and its mechanism. Methods Kunming mice were inflicted second-degree burn covering 15% of the total body surface （TBSA） on the back. Another five normal mice served as controls. The mouse peritoneal macrophage cell line RAW264.7 was stimulated by 0.1 - 1μg/ml lipopolysaccharide for 6 h. The mouse tissues of liver, lungs and spleen on day 1 or 7 after burn and RAW264.7 cells were disposed to extract total RNA and protein, then IFIT1 mRNA and protein levels were detected by reverse transcriptionpolymerase chain reaction and Western blotting. Results Transcription of IFIT1 in liver, lungs and spleen of burned mice was apparently increased one day after burn, and 7 days later, the mRNA recovered to normal level. IFIT1 protein levels were elevated one day after burn, and still detectable 7 days later. In vitro, lipopolysaccharide strongly induced the expressions of IFIT1 mRNA and protein in RAW264.7 cells. Conclusion The expression level of IFIT1 in mice was sharply elevated at the early stage of burn injury, and endotoxemia may be one reason of this change.