重度爆炸冲击伤所致肾功能损伤与肾小管上皮细胞铁死亡

Renal impairment and ferroptosis of renal tubular epithelial cells due to severe blast injuries

摘要

目的：探讨重度爆炸冲击伤所致的肾功能损伤，以及与铁死亡相关的损伤机制。方法：山羊布置于距离8 kg三硝基甲苯（trinitrotoluene,TNT）当量的爆炸物中心3 m处开展爆炸致伤实验。测量爆炸冲击波物理参数，开展冲击伤病理严重度分级评分以评估伤情严重度；检测伤前及伤后1、3、6、24 h的生命体征、血气及肾功能指标，于致伤后24 h取肾脏组织进行组织切片苏木素-伊红染色、Fe²⁺含量及铁死亡相关标志蛋白胱氨酸-谷氨酸反向转运体（system Xc-transporter,xCT）和谷胱甘肽过氧化物酶4（glutathione peroxidase 4,GPX4）的表达变化检测，以及肾脏组织切片普鲁士蓝染色，以探查肾功能的损伤情况及肾脏组织细胞损伤的铁死亡相关机制。结果：爆炸致伤后实验山羊的冲击伤以重度为主（轻度2.8%、中度36.1%、重度47.2%、极重度13.9%），冲击伤病理严重度分级评分为2.56±0.15；与伤前相比，伤后山羊心率加快（F=12.750,P<0.01）、呼吸频率加快（F=6.500,P<0.01）、肛温下降（F=3.496,P<0.05），血氧分压降低（F=24.630,P<0.01）、血氧饱和度降低（F=18.560,P<0.01）；血尿酸升高（F=22.320,P<0.01）、血肌酐升高（F=15.350,P<0.01）、血尿素氮升高（F=22.310,P<0.01）。与对照组相比，爆炸冲击伤后24 h可见肾小管上皮细胞肿胀、管腔狭窄，肾组织Fe²⁺含量升高（t=5.933,P<0.01），肾组织GPX4蛋白相对表达量下降（t=7.924,P<0.01），肾组织xCT蛋白相对表达量下降（t=4.483,P<0.01），肾小管上皮细胞处大量铁离子沉积。结论：实验山羊布置于距离8 kg TNT当量的爆炸物中心3 m处可致重度爆炸伤冲击伤，引起缺氧、肾功能损伤及肾小管上皮细胞铁死亡的发生。

Abstract

Objective To investigate renal impairment and ferroptosis due to severe blast injuries and related mechanism. Methods The goats were placed 3 meters away from the center of an 8 kg TNT-equivalent explosive to carry out blast injury experiments. The physical parameters of blast waves were measured，and the pathological severity of blast injuries was graded and scored to assess the severity of injuries. Vital signs，blood gas parameters，and renal function markers were measured before injury and at 1，3，6，and 24 hours after injury. Renal tissue samples were collected at 24 hours after injury to prepare tissue sections，which were used to perform HE staining and measure the changes in the content of Fe²⁺ and the expression of the ferroptosis-related marker proteins xCT and GPX4 in renal tissue，and Prussian blue staining was performed for renal tissue sections to investigate the mechanism associated with renal impairment and ferroptosis of renal cells. Results Severe blast injuries accounted for the highest proportion of 47.2% in experimental goats，while mild，moderate，severe，and extremely severe injuries accounted for 2.8%，36.1%，47.2%，and 13.9%，respectively，and the pathologic severity score of blast injury was 2.56±0.15. For the goats after blast injury，there were significant increases in heart rate（F=12.750，P<0.01） and respiratory rate（F=6.500，P<0.01） and significant reductions in anal temperature（F=3.496，P<0.05），partial pressure of blood oxygen（F=24.630，P<0.01），and blood oxygen saturation（F=18.560，P<0.01），as well as significant increases in the levels of blood uric acid（F=22.320，P<0.01），serum creatinine（F=15.350，P<0.01），and blood urea nitrogen（F=22.310，P<0.01）. Compared with the control group，swelling of renal tubular epithelial cells and narrowing of tubular lumen were observed at 24 hours after blast injury，with a significant increase in the content of Fe²⁺ in renal tissue（t=5.933，P<0.01），significant reductions in the relative expression protein levels of GPX4（t=7.924，P<0.01） and xCT（t=4.483，P<0.01） in renal tissue，and deposition of a large amount of iron ions in renal tubular epithelial cells. Conclusion Experimental goats placed 3 meters away from the center of an 8 kg TNT-equivalent explosive can cause severe blast injuries，resulting in the onset of hypoxia，renal impairment，and ferroptosis of renal tubular epithelial cells.

Graphical abstract

关键词

爆炸冲击伤 / 铁死亡 / 肾损伤 / 肾小管上皮细胞

Key words

blast injury / ferroptosis / renal impairment / renal tubular epithelial cells

基金资助

后勤科研重大资助项目(ALJ18J001)