单免疫球蛋白白细胞介素1受体相关蛋白在脂多糖诱导的急性肺损伤小鼠肺组织中表达的研究

目的 通过构建小鼠急性肺损伤（ ALI） 模型, 观察单免疫球蛋白白细胞介素1 受体相关蛋白（ SIGIRR） 在正常小鼠及ALI 小鼠模型肺组织中的表达规律, 为SIGIRR 在ALI 预防及治疗方面的应用提供基础。方法 将30 只雄性BALB/C 小鼠随机分为对照组及脂多糖（ LPS） 组, 每组15只。腹腔注射戊巴比妥钠麻醉满意后, 行气管插管, 呼吸机辅助呼吸。气管内缓慢滴入LPS 溶液（ 1 mg/kg, 500 μL） 构建ALI 模型。对照组按上述操作步骤, 气管内注射入生理盐水。观察小鼠肺弹性阻力的变化; 肺水肿程度观察; 肺组织病理切片HE 染色后光镜下观察肺组织病变情况; 收集小鼠支气管肺泡灌洗液（ BALF） , ELISA 法检测细胞因子白细胞介素1β（ IL-1β） 、肿瘤坏死因子α（ TNF-α） 和IL-6 浓度; 收集肺组织, ELISA 法检测肺组织匀浆内一氧化氮（ NO） 浓度和髓过氧化物酶（ MPO） 活性;免疫组化检测肺组织中SIGIRR 表达,Western blot 检测各个时间点肺组织SIGIRR 表达水平的变化。结果 模型小鼠肺弹性阻力较对照组明显上升; 模型小鼠肺组织湿/ 干重比值较对照组明显增高; 模型小鼠肺组织的病理呈现典型的ALI 病理改变特征, 对照组小鼠则表现为正常的肺组织病理学特点;模型建立3 h后, ELISA 法检测ALI 小鼠BALF中IL-1β、TNF-α及IL-6 浓度分别为（ 517 ±18） pg/mL、（ 3523 ±168） pg/mL和（ 676 ±25） pg/mL, 显著高于对照组（ P 〈 0. 05） ; ELISA 法检测模型小鼠肺组织匀浆液中NO 的浓度和MPO 的活性分别为（ 88. 1 ±2. 6） μmol /mL 和（ 215 ±7） μIU/mL, 显著高于对照组（ P 〈0. 05） ; 免疫组化染色提示SIGIRR 在正常的小鼠肺组织中存在表达, 主要分布于肺泡及气道上皮细胞; 模型小鼠肺组织Western blot 结果表明： LPS 诱导小鼠ALI 后1 h, SIGIRR 的表达即开始下降, 3 h 后降至最低, 随后缓慢恢复, 至24 h时基本恢复正常表达水平。结论 SIGIRR 在正常的小鼠肺组织中存在表达, 主要分布于肺泡及气道上皮细胞, LPS 诱导小鼠ALI 后SIGIRR 的表达短期内下降, 至24 h后基本恢复正常表达水平。

The Expression of Single Immunoglobin IL-1Receptor Related Protein in Normal Mice Lung Tissuesand Its Changes in the Lipopolysaccharide Induced Acute Lung Injured Mice

Objective To investigate the expression of single immunoglobulin IL-1 receptor-relatedprotein （ SIGIRR） in normal mice and LPS-induced ALI mice.？Methods The animal model of acute lunginjury （ ALI） was established by intratracheal instillation of LPS in BALB/ c mice. After exposure to LPS,lung elastance and lung wet/dry weight ratio were observed, and pulmonary histological changes wereevaluated by hematoxylin-eosin stain. The bronchoalveolar lavage fluid （ BALF） and lung tissues were harvested at specific time point. The concentrations of IL-1β, TNF-αand IL-6 in BALF were measured by ELISA. The concentrations of nitric oxide （ NO） and the myeloperoxidase （ MPO） activity in lung tissuehomogenates were measured by ELISA. SIGIRR expression in lung tissue was observed byimmunocytochemistry and Western blot in order to find out whether there is relationship between SIGIRRexpression and ALI.？Results After intratracheal instillation of LPS 0. 5h, the elastance of lung began toincrease gradually as time went by and had significantly increased compared with the control group. Afterintratracheal instillation of LPS 24h, the lung wet /dry ratio peaked to 6. 12 ±0. 88 and had significantlyincreased compared with the control group. In the LPS group, the lung tissues displayed typical ALIcharacteristics. After intratracheal instillation of LPS 3h, the concentrations of IL-1β, TNF-α, IL-6 and NO inBALF peaked to （ 517 ±18） pg/mL, （ 3523 ±168） pg/mL, （ 676 ±25） pg/mL and （ 88. 1 ±2. 6） μmol /mLrespectively. The peak activity of MPO in lung homogenates reached to （ 215 ±7） μIU/mL after LPSinstillation. Compared with the control group, the concentrations of IL-1β, TNF-α, IL-6 and the activity ofMPO in the LPS group markedly increased. Immunocytochemistry and Western blot analysis showed thatSIGIRR was constitutively expressed in normal mice lung and was mainly detected in the pulmonary epithelialcells. After LPS stimulation, SIGIRR protein levels were down-regulated.？Conclusions SIGIRR isconstitutively expressed in normal mice lung and is mainly detected in the pulmonary epithelial cells. Theexpression of SIGIRR is down-regulated after LPS challenge.