脂肪干细胞对脂多糖诱导急性肺损伤大鼠炎性因子表达的影响

Effect of adipose-derived stem cells on inflammatory factors expression in rats with lipopolysaccharide-induced acute lung injury

目的：探讨脂肪干细胞（ADSCs）对脂多糖（LPS）诱导大鼠急性肺损伤（ALI）炎性因子的影响及其抗炎作用机制。方法雄性SD大鼠70只，按随机数字表法分为正常对照组（10只）、LPS模型组（30只）、ADSCs干预组（30只）。腹腔注射LPS8mg/kg制备大鼠ALI模型，ADSCs干预组于制模30min后尾静脉注射300μLADSCs进行干预；正常对照组无处理直接取标本，其余两组在6、24、72h取标本。取股动脉血检测动脉血氧分压（PaO2）及乳酸水平；取左心室血，用酶联免疫吸附试验（ELISA）检测血清髓过氧化物酶（MPO）和白细胞介素-10（IL-10）水平；开胸取肺组织，检测肺湿/干重（W/D）比值，光镜下观察肺组织病理学改变，并用蛋白质免疫印迹试验（WesternBlot）检测肺组织核转录因子-κB（NF-κB）表达。结果与正常对照组比较， LPS模型组6h起肺组织损伤即逐渐加重，肺W/D比值、血乳酸、血清MPO和IL-10水平及肺组织NF-κB表达均显著增加，PaO2显著下降。与LPS模型组比较，ADSCs干预组6h起肺组织损伤程度即明显减轻，肺W/D比值、血乳酸、血清MPO水平和肺组织NF-κB表达均明显降低，PaO2显著增加，72h已接近正常对照组水平〔肺W/D比值：6h为5.33±0.29比5.77±0.42，72h为5.14±0.46比5.43±0.38；血乳酸（mmol/L）：6h为3.6±1.0比5.7±1.1，72h为3.1±1.0比3.8±1.2；血MPO（μg/L）：6h为1.50±0.90比2.70±1.85，72h为0.46±0.30比0.71±0.22；肺NF-κB（灰度值）：6h为0.40±0.11比0.50±0.09，72h为0.24±0.03比0.33±0.06；PaO2（mmHg，1mmHg＝0.133kPa）：6h为78.0±4.1比74.5±3.2，72h为89.3±9.4比81.9±3.4；均P＜0.05〕，IL-10水平仅在24h显著高于LPS模型组（ng/L：27.75±15.49比17.52±6.56，P＜0.05）。结论 ADSCs可有效减轻LPS诱导ALI大鼠的炎症反应，可能与ADSCs抑制NF-κB活性而阻断炎性因子释放有关。

Objective To explore the effect of adipose-derived stem cells （ADSCs） on inflammatory factors in rats with lipopolysaccharide （LPS）-induced acute lung injury （ALI） and the possible mechanism of anti-inflammatory. Methods Seventy male Sprague-Dawley （SD） rats were randomly divided into normal control group （n = 10）, LPS model group （n = 30）, and ADSCs intervention group （n = 30） by random number table. ALI model was reproduced by intraperitoneal injection of 8 mg/kg LPS, and the rats in ADSCs intervention group received tail vein injection of 300 μL ADSCs 30 minutes after the model reproduction, the samples of normal control group were harvested immediately without any intervention, and the specimens in remained two groups were taken at 6, 24, 72 hours respectively. Arterial partial pressure of oxygen （PaO2） and lactate level in femoral artery were determined. Enzyme-linked immunosorbent assay （ELISA） was used to detect the serum myeloperoxidase （MPO） and interleukin-10 （IL-10） in the blood of left ventricle. Lung wet/dry weight （W/D） ratio was detected by thoracotomy, and the pathological changes of lung tissue were observed under an optical microscope. Western Blot was used to detect the protein expression of nuclear factor-κB （NF-κB） in lung tissue of rats. Results Compared with the normal control group, the damage degree of lung tissue of LPS model group was significantly heavier from 6 hours, and lung W/D ratio, blood lactate, MPO, IL-10 and expression level of NF-κB in lung tissue were significantly increased respectively, while PaO2 was decreased significantly. Compared with LPS model group, the damage degree of lung tissue of ADSCs intervention group was significantly reduced from 6 hours, and lung W/D ratio, blood lactate, MPO, and NF-κB expression in lung tissue were significantly decreased, while PaO2 was increased significantly, and it became normal at 72 hours [lung W/D ratio： 5.33±0.29 vs. 5.77±0.42 at 6 hours, 5.14±0.46 vs. 5.43±0.38 at 72 hours; blood lactate （mmol/L）： 3.6±1.0 vs. 5.7±1.1 at 6 hours, 3.1±1.0 vs. 3.8±1.2 at 72 hours; blood MPO （μg/L）： 1.50±0.90 vs. 2.70±1.85 at 6 hours, 0.46±0.30 vs. 0.71±0.22 at 72 hours; NF-κB （gray value）： 0.40±0.11 vs. 0.50±0.09 at 6 hours, 0.24±0.03 vs. 0.33±0.06; PaO2 （mmHg, 1 mmHg = 0.133 kPa）： 78.0±4.1 vs. 74.5±3.2 at 6 hours, 89.3±9.4 vs. 81.9±3.4 at 72 hours; all P 〈 0.05]. The IL-10 level was significantly higher than that of LPS model group only at 24 hours （ng/L： 27.75±15.49 vs. 17.52±6.56, P 〈 0.05）. Conclusion ADSCs can effectively relieve the inflammatory response of ALI induced by LPS, probably by inhibiting the expressions of NF-κB and blocking the release of inflammatory cytokines.