肺角质细胞生长因子受体在大鼠急性脊髓损伤后肺水肿中的表达及作用

Expression of lung keratinocyte growth factor receptor in the pulmonary edema of rats with acutespinal cord injury

目的探讨大鼠急性脊髓损伤（acute spinal cord injury，ASCI）后不同时相点肺组织角质细胞生长因子受体（keratinocyte growth factor receptor，KGFR）的表达及其与肺水肿的关系。方法成年Wistar大鼠32只，体重240-260g，雌雄不限。按随机数字表法分为实验组和对照组，每组16只，每组分为造模后24h、3d、1周、2周共4个时相点，每个时相点4只大鼠。实验组均采用C。脊髓Allen打击法制作大鼠ASCI模型，打击剂量为10g×2．5cm，对照组仅暴露c，脊髓。检测各时相点两组大鼠肺湿干重比，使用Westernblot技术检测肺组织KGFR蛋白表达水平，RT-qPCR技术检测肺组织KGFRmRNA表达水平。结果大鼠ASCI后肺组织KGFR蛋白及mRNA表达水平均于伤后24h开始下降，分别为0．23±0．06，0．0121±0．0023，伤后3d达最低值，分别为0．17±0．04，0．0085±0．0017，伤后1周含量开始回升。伤后24h和3d实验组肺组织KGFRmRNA表达与对照组差异有统计学意义（P〈0．05），伤后各时相点KGFR蛋白表达均与对照组差异有统计学意义（P〈0．05）。KGFR表达的变化趋势与肺水肿严重程度的变化趋势同步。结论ASCI后肺组织KGFR表达显著降低，可能与ASCI后肺水肿的形成有关。

Objective To investigate the expression of lung keratinocyte growth iactor receptor （KGFR） in rats with acute spinal cord injury （ASCI） in different time points and its role in lung edema. Methods Thirty-two adult Wistar rats weighing 240 g to 260 g were assigned to experimental group （ n = 16） and control group （n = 16） according to the random number table. Each group consisted of time points of 24 hours, 3 days, 1 week and 2 weeks after the modeling （4 rats per time point）. A rat model of ASCI in experimental group was induced at C7 segment by dropping a weight of 10 g from the height of 2.5 cm （ Allen＇ s method）. In control group, laminas were removed only, leaving spinal cord at C7 intact. Rats were sacrificed at each time point for measurement of lung wet/dry weight ratio, Western blot analysis of expression of lung KGFR protein and RT-qPCR detection of lung KGFR mRNA expression. Results After ASCI in rats, the expressions of lung KGFR protein and mRNA began to drop at 24 hours （0.23 ±0.06, 0,012 1 ±0.002 3）, reached the trough at 3 days （0.17 ±0.04, 0.008 5±0.001 7） and picked up at 1 week. Expression of lung KGFR mRNA in experiment group showed statistically significant difference from that in control group at 24 hours and 3 days （ P 〈 0.05 ） , whereas in each time point the difference of KGFR protein expression between experiment and control groups was statistically significant（P 〈0.05 ） . Variation trend of KGFR expression was in parallel with the severity degree of pulmonary edema. Conclusion Lung KGFR presents significant down-regulation in ASCI rats and this may be associated with the development of pulmonary edema after ASCI.