大鼠脂肪栓塞综合征模型中自噬水平的变化

The expression of autophagy - related protein in the model of fat embolism syndrome in rats

目的 观察大鼠脂肪栓塞综合征（fat embolism syndrome， FES）模型中自噬水平的变化。方法 选择健康雄性SD大鼠60只，体质量（250±20）g，采用随机数字表法, 将大鼠平均分为6组（n=10）：对照组、FES 1 h组、FES 6 h组、FES 12 h组、FES 24 h 组和雷帕霉素＋FES 24 h组。除对照组均经大鼠尾静脉注射同种异体肾周脂肪0.706 mL/kg，对照组尾静脉注射等剂量无菌等渗盐水；雷帕霉素组在建立大鼠FES模型前30 min经尾静脉注射雷帕霉素2 mg/kg。分别于模型建立后1、6、12、24 h取10只大鼠处死取肺组织，光镜下观察肺组织形态学变化，测定肺组织W/D，检测肺组织髓过氧化物酶（MPO）活性，Western blotting 法测定LC3-Ⅰ/LC3-Ⅱ、p62、mTOR/p-mTOR及p70S6K/p- p70S6K蛋白的表达。结果 与对照组比较，FES组肺组织损伤严重。FES组大鼠肺组织W/D值和MPO活性较对照组明显升高（P〈0.05），p62、mTOR/p- mTOR和p70S6K/p- p70S6K表达明显高于对照组（P〈0.05）；雷帕霉素＋FES 24 h组较FES 24 h组，p62、mTOR/p- mTOR和p70S6K/p- p70S6K表达下调（P〈0.05）。结论 自噬参与了FES的发病过程，并且在模型中被抑制。

Objective To observe the expression of autophagy - related protein in the model of fat embolism syndrome in rats. Methods Sixty healthy male SD rats, weighing （250 ± 20 ） g, were assigned to control group （FES 0 h group）, FES 1 h group, FES 6 h group, FES 12 h group and FES 24 h group, according to the random number table. Allogeneic perinephric fat （0. 706 mL/kg） was injected through rat caudal veins in FES group. Instead isotonic saline in an equal volume was given to rats in control group. The rats in the fat embolism ＋ Rapamycin group received the autophagy activator Rapamycin by intraperitoneal injection at a dosage of 2 mg/kg 30 minutes before fat injection. Lung samples were harvested from each group to detect pathological morphology, lung weight to dry ratio （W/D）, and activity in myeloperoxidase （MPO） was detected by real- time reverse transcriptase polymerase chain reaction （ RT - PCR）. The protein expression of autophagy was detected by Western blot. Results Compared with control group, lung tissues in FES group were seriously injured. Lung W/D value and activity of MPO in lung tissue were higher in FES group than those in control group （ P 〈 0.05 ）. Compared with control group, the expression of p62, mTOR/p - mTOR and p70S6K/p - p70S6K protein was up - regulated in FES group （ P 〈 0.05）. The expression of p62, mTOR/p - roTOR and p70S6K/p - p70S6K protein was down - regulated in the FES 24 h ＋ Rapamycin group compared to the FES 24 h group （P 〈 0.05）. Conclusion Autophagy is involved in the pathogenesis of FES, and it is inhibited in the model of fat embolism syndrome.