哮喘小鼠胸腺活化调节趋化因子及其受体的表达

The expression of thymus and activation-regulated chemokine and the receptor in asthma mice

目的探讨胸腺活化调节趋化因子(TARC)及其受体CCR4在哮喘小鼠气道炎症中的作用。方法清洁级健康雄性Balb/c小鼠20只随机分成两组,分别为对照组、哮喘组。以卵清白蛋白(OVA)致敏和激发建立小鼠哮喘模型。末次激发24h后留取血液、支气管肺泡灌洗液(BALF)及肺组织。BALF行细胞计数及分类;应用酶联免疫吸附试验(ELISA)法测定BALF和血清中TARC和白介素(IL)-4蛋白的浓度;光镜观察肺组织病理变化;逆转录-聚合酶链反应(RT- PCR)法测定肺组织中TARC mRNA、CCR4 mRNA的表达;采用免疫组织化学法测定肺组织中TARC蛋白的表达。结果哮喘组BALF和血清中TARC的浓度[分别为(458.36±114.98)pg/ml、(145.56±28.38)pg/ml]均显著高于对照组[分别为(5.06±2.38)pg/ml、(73.79±29.27)pg/mi] (P<0.01);哮喘组BALF和血清中IL-4浓度[分别为(35.46±12.47)pg/ml、(3.82±1.12)pg/ml]均显著高于对照组[分别为(3.83±1.57)pg/ml、(0.88±0.33)pg/ml](P<0.01);肺组织中TARC mRNA及其受体CCR4 mRNA的表达,哮喘组[分别为(1.12±0.08)、(0.91±0.13)]显著高于对照组[分别为(0.53±0.12)、(0.62±0.10)](P<0.01);免疫组化显示TARC蛋白主要表达于支气管上皮细胞,哮喘组表达量(0.103±0.015)显著高于对照组(0.045±0.007)(P<0.01)。结论TARC及其受体CCR4在哮喘小鼠肺组织中表达增加,参与哮喘气道炎症的发病过程,气道上皮细胞是TARC重要的来源细胞。

Objective To study the role of thymus and activation-regulated chemokine （TARC） and the ehemokine receptor 4 （CCR4） on airway inflammation of asthma mice. Method Twenty male Balb/c mice were randomly divided into the control group and asthma group. Asthma mice were sensitized with ovalbumin （OVA） and A1（OH）3, and repeatedly challenged with aerosolized OVA. Blood samples, bronehoalveolar lavage fluid （BALF） and lung tissues were collected from mice 24 hours after the last challenge. The total cell numbers and the cell differentials of BALF cells were counted. The levels of TARC, and IL-4 in both BALF and serum were measured by enzyme-linked immunosorbent assay （ELISA）. The pathological changes of lung tissuewere observed under light microscopy. The expression of TARC mRNA and CCR4 mRNA were detected by reverse transcription polymerase chain reaction （RT-PCR） and the expression of TARC protein was detected by immunohistoehemistry. Results The concentrations of TARC in both BALF and serum of asthma group [ （458.36±114.98） pg/ml and （145.56±28.38） pg/ml, respectively] were markedly higher than those in control group [ （5.06±2.38） pg/ ml and （73.79±29.27） pg/ml, respeetivelyl, （P 〈 0.01, respectively）. The levels of IL-4 in both BALF and serum of asthma group [（35.46±12.47） pg/ml and （3.82±1.12） pg/ml, respectively] were significantly higher than those in control group [ （3.83±1.57） pg/ml and （0.88±0.33） pg/ml, respectively] （ P 〈 0.01, respectively）. The expressions of TARC mRNA and CCR4 mRNA in asthma group [ （1.12±0.08） and （0.91±0.13）, respeetivelyl were significantly higher than those in control group [ （0.53±0. 12） and （0.62±0. 10）, respeetivelyl （ P 〈 0.01, respectively）. Immunohistoehemistry showed that the predominant ceils in lung tissues that expressed TARC were epithelial cells. The protein expression of TARC in bronchus epithelial cell of asthma group （0.103±0.015） was significantly higher than those in control group （0.045±0.007） （P 〈 0.01）. Conclusions TARC and CCR4 is up-regulated in allergic asthma mice, which may involve in the development of asthma. Furthermore, the predominant ceils in lung tissue that expressed TARC are bronchial epithelium.