骨髓间充质干细胞对髋部骨折诱导的老年大鼠急性肺损伤的保护机制

目的　探讨骨髓间充质干细胞（bone marrow-derived mesenchymal stem cells，BMSCs）对老年单侧髋部骨折大鼠急性肺损伤（acute lung injury, ALI）的保护作用。 方法　将15月龄雌性WISTAR大鼠分为对照组（不做任何处理）、模型组（右髋部骨折+生理盐水）、治疗组（右髋部骨折+BMSCs）。治疗组于造模后经尾静脉注射1 ml BMSCs(2.5×106/ml)，模型组给予等体积生理盐水。创伤后24 h进行肺组织病理评分，ELISA法检测检测肺组织MPO含量、肺及血液炎症因子（TNF-α、IL-6、IL-10）水平。 结果　与对照组相比，模型组肺部病理学评分、肺组织MPO水平、肺及血液炎症反应相关指标均明显升高（P<0.01）。BMSCs处理可明显降低肺组织病理学评分，肺组织MPO水平、肺及血液炎症反应相关指标下调，同时IL-10水平有更明显的增高（P<0.01）。 结论 髋部骨折可诱发老年大鼠急性肺损伤，BMSCs移植对老年髋部骨折大鼠肺损伤具有保护作用，其机制与缓解全身及肺部炎症反应有关。

The protective effect of bone marrow-derived mesenchymal stem cells on acute lung injury after hip fracture in elderly rat

Objective　To investigate the protective effect of bone marrow-derived mesenchymal stem cells on acute lung injury (ALI) after unilateral hip fracture in elderly rat.　Methods　15 month old WISTAR rat were randomly divided into three groups: a control group (n=15)、a model group(hip fracture+NS, n=15) and a treated group (hip fracture+BMSCs, n=15). 1 ml BMSCs（2.5×106/ml）were injected through the caudal vein in the treated group, and the same volume of NS was injected into the model group Histologic changes were examined at 24 hours after fracture. And the concentration of MPO and related inflammatory factors in the impaired lung tissue and blood were examined through enzyme-linked immunosorbent assay (ELISA).　Results　Compared with the control group,the histopathological damage of lung, the concentration of MPO and related inflammatory factors were obviously enhanced（P<0.01）. Compared with the model group,application of BMSCs significantly ameliorated the inflammatory lesions of the lung, increased the concentration of IL-10, and further down-regulated the concentration of MPO and other inflammatory factors（P<0.01）.　Conclusions　ALI can be induced by hip fracture in aged rats. BMSCs shows a certain protective effect on ALI with down-regulation of inflammatory response in systemic and pulmonary as a possible mechanism.