研究N-乙酰半胱氨酸（NAC）上调细胞FLICE抑制蛋白（c-FLIP）表达对脓毒症小鼠急性肾损伤的作用。

将30只雄性BALB/c小鼠分为假手术组、脓毒症组和NAC组，每组各10只。采用盲肠结扎穿孔术法制备脓毒症小鼠模型，假手术组除不结扎穿刺盲肠外，其余手术步骤相同，NAC组小鼠术后15 min尾静脉注射NAC 100 mg/kg。造模成功后24 h取小鼠肾脏，光镜下观察肾脏组织病理变化；采用实时定量PCR（RT-PCR）法检测c-FLIP mRNA表达；采用Western-blotting法检测c-FLIP蛋白表达；复制上述实验观察96 h内小鼠的生存情况。

与假手术组相比，脓毒症组小鼠肾小球萎缩、肾小管上皮细胞变形、肾小管腔内可见大量肾细胞间质和碎片，而NAC组小鼠肾脏组织病变明显减轻。三组间肾脏组织病理学损伤评分、c-FLIP mRNA及蛋白表达比较，差异均有统计学意义（F = 101.400、31.720、20.330，P均< 0.05）。进一步两两比较发现，CLP组小鼠肾脏组织病理学损伤评分较假手术组显著升高（P < 0.001），NAC组小鼠肾脏组织病理学损伤评分较CLP组显著降低（P < 0.001）。与假手术组相比，脓毒症组小鼠c-FLIP mRNA及蛋白表达均明显下降（P均< 0.05），NAC组c-FLIP的蛋白表达有所降低（P < 0.05）；与脓毒症组相比，NAC组小鼠c-FLIP mRNA及蛋白表达均显著上升（P均< 0.05）。Kaplan-Meier生存曲线结果显示，三组小鼠生存情况比较，差异有统计学意义（χ²= 8.806，P= 0.012）。进一步两两比较发现，脓毒症组及NAC组小鼠的存活数量均较假手术组显著降低（P均< 0.017），而NAC组小鼠存活数量较脓毒症组明显升高（P < 0.017）。

NAC通过上调c-FLIP表达对脓毒症小鼠的急性肾损伤具有显著的保护作用。

To investigate the effect of N-acetylcysteine (NAC) on acute kidney injury in septic mice by up-regulating the expression of cellular FLICE inhibitory protein (c-FLIP).

Thirty male BALB/c mice were randomly divided into the sham operation group (n= 10), sepsis group (n= 10) and NAC group (n= 10). The sepsis mouse model was prepared by cecal ligation and perforation. The sham operation group had the same procedure except for the ligation of puncture caecum. NAC (100 mg/kg) was injected into the tail vein of mice in the NAC group 15 min after operation. The kidney of mice was taken 24 h after the successful modeling, and then pathological changes of kidney tissues were observed under light microscope. The expression of c-FLIP mRNA was detected by quantitative real-time polymerase chain reaction (RT-PCR), and the expression of c-FLIP protein was detected by the Western-blotting method. The above experiment was replicated to observe the mortality of mice within 96 h.

Compared with the sham operation group, glomerular atrophy, renal tubular epithelial cell deformation, and large amount of interstitial cells and fragments in renal tubule lumen were observed in the sepsis group, while renal tissue lesions in the NAC group significantly reduced. There were significant differences in the renal histopathological injury score, and expressions of c-FLIP mRNA and protein among these three groups (F= 101.400, 31.720, 20.330; all P < 0.05). Further comparison showed that the score of renal histopathological injury in the sepsis group was significantly higher than that in the sham operation group and NAC group (both P < 0.001). Compared with the sham operation group, the c-FLIP mRNA and protein expressions in the sepsis group decreased significantly (both P < 0.05), and the c-FLIP protein expression in the NAC group decreased (P < 0.05). Compared with the sepsis group, the c-FLIP mRNA and protein expressions in the NAC group increased significantly (both P < 0.05). The Kaplan-Meier survival curve showed that the survival of mice was significantly different among these three groups (χ²= 8.806, P= 0.012). Further comparison showed that the survival rate was significantly lower in the sepsis group and NAC group than in the sham operation group (both P < 0.017), while it was significantly higher in the NAC group than in the sepsis group (P < 0.017).

NAC has a significant protective effect on acute kidney injury in septic mice by up-regulating the c-FLIP expression.