賈麗萍 蔡梓滔 陳祖光 劉美丹 姚衛(wèi)民
食管酸灌注對(duì)哮喘小鼠氣道炎癥及BRP-39濃度的影響
賈麗萍1蔡梓滔2陳祖光2劉美丹2姚衛(wèi)民2
目的 觀察食管酸灌注對(duì)哮喘小鼠氣道炎癥的影響及BRP-39濃度與哮喘小鼠氣道炎癥的關(guān)系。方法 60只雄性BALB/c小鼠隨機(jī)分成6組(正常組、灌鹽組、灌酸組、哮喘組、哮喘灌鹽組、哮喘灌酸組),用OVA致敏和激發(fā)的方法建立哮喘模型,用食管下段鹽酸灌注建立胃食管反流(gastroesophageal reflux,GER)模型,末次抗原激發(fā)后24小時(shí)處死小鼠,ELISA法檢測(cè)回收的BALF及血清中的BRP-39;BALF細(xì)胞沉渣涂片后染色計(jì)數(shù)細(xì)胞總數(shù)及分類計(jì)數(shù)。 結(jié)果 (1)單純哮喘組及哮喘灌鹽、哮喘灌酸組小鼠BALF中細(xì)胞總數(shù)及嗜酸性粒細(xì)胞、中性粒細(xì)胞、淋巴細(xì)胞的細(xì)胞分類數(shù)均較對(duì)照組高,以嗜酸性粒細(xì)胞增高最為明顯,具有統(tǒng)計(jì)學(xué)意義(P<0.05);灌酸組小鼠BALF中細(xì)胞總數(shù)及中性粒細(xì)胞、淋巴細(xì)胞的細(xì)胞分類數(shù)均較對(duì)照組高,以中性粒細(xì)胞增高最為明顯,具有統(tǒng)計(jì)學(xué)差異(P<0.05);正常組與灌鹽組小鼠,哮喘灌鹽組與哮喘灌酸組小鼠無(wú)統(tǒng)計(jì)學(xué)差異。(2)與對(duì)照組比較,除灌鹽組外,其余各組特別是哮喘灌酸組,BALF及血清中BRP-39的濃度均明顯升高,且與BALF中的細(xì)胞總數(shù)及中性粒細(xì)胞、嗜酸性粒細(xì)胞呈正相關(guān)(P<0.05~P<0.01) 結(jié)論 多次食管酸灌注可引起氣道內(nèi)炎癥反應(yīng),伴有血清及BALF中的BRP-39濃度明顯升高,可能與GER誘發(fā)或加重哮喘有關(guān)。
小鼠;哮喘;胃食管反流;BRP-39
近20年來(lái)支氣管哮喘發(fā)病率持續(xù)增高,控制欠佳,哮喘仍然是全球主要的公共衛(wèi)生問(wèn)題之一。Osler[1]首次提出GER與哮喘的相關(guān)性,近年越來(lái)越多的證據(jù)表明GER在難控性哮喘中有較高的患病率,被認(rèn)為是哮喘控制欠佳原因之一,可能是哮喘發(fā)生發(fā)展的獨(dú)立危險(xiǎn)因素[2]。GER引起哮喘發(fā)生發(fā)展的機(jī)制并不明確,反射學(xué)說(shuō)認(rèn)為食管受酸刺激后,經(jīng)食管-支氣管反射,引起肺內(nèi)神經(jīng)源性炎癥反應(yīng),因此研究NKA、NKB、SP、CGRP等相關(guān)神經(jīng)肽的研究較多[3],而探討其他炎癥反應(yīng)途徑的研究較少。本實(shí)驗(yàn)通過(guò)建立胃食管反流及哮喘小鼠模型,觀察GER對(duì)哮喘小鼠肺部炎癥的影響及BRP-39在不同造模組小鼠血清及BALF中的濃度變化情況,探討B(tài)RP-39在GER促進(jìn)哮喘發(fā)生發(fā)展中的可能作用。
一、材料
雞卵白蛋白(OVA,Grade V)(美國(guó)Sigma公司);氫氧化鋁[AI(OH)3]凝膠(美國(guó)Sigma公司);豬胃蛋白酶(美國(guó)Sigma公司);胰酶(美國(guó)JRH公司);HCl(廣州化學(xué)試劑公司);YKL-40 試劑盒(廣州拓科達(dá)生物科技有限公司);自制霧化箱(20cm×30cm×30cm,樹(shù)脂箱);百瑞超聲霧化器(德國(guó)百瑞公司);12號(hào)小鼠灌胃針;
二、動(dòng)物分組及造模方法
1 動(dòng)物分組:60只清潔級(jí),雄性,BALB/c小鼠,8-9周齡,體重18-20g,購(gòu)自廣東省實(shí)驗(yàn)動(dòng)物中心,隨機(jī)分成6組,每組10只。A組(正常對(duì)照組):未予任何處理;B組(灌鹽組):生理鹽水灌注食管;C組(灌酸組):稀鹽酸灌注食管;D組(哮喘組):雞卵白蛋白OVA致敏和激發(fā);E組(哮喘并灌鹽組):哮喘造模同時(shí),致敏第一天開(kāi)始食管灌注生理鹽水(灌注方法同B組);F組(哮喘并灌酸組):哮喘造模同時(shí),致敏第一天開(kāi)始食管灌注稀鹽酸(灌注方法同C組)。
2 造模方法
(1) 建立哮喘小鼠模型及給藥:參照文獻(xiàn)[4-5]并加以改進(jìn),方法如下:① 致敏:哮喘小鼠,于第0天、第7天、第14天予腹腔注射20μg OVA(20mg Al(OH)3+200μL NS)致敏液0.2mL。② 抗原激發(fā):哮喘小鼠,于實(shí)驗(yàn)流程的19天,配制含1%OVA的生理鹽水霧化溶液,現(xiàn)配現(xiàn)用。將哮喘組、哮喘灌鹽組及哮喘灌酸組小鼠分批置于自制霧化箱(30cm×20cm×15cm)中,每批用10mL的霧化液,每天一次,每次霧化約40分鐘,共霧化3天,以出現(xiàn)抓耳撓腮、點(diǎn)頭呼吸、腹肌收縮、匍匐不起等癥狀時(shí)代表誘喘成功。
(2) 建立胃食管反流小鼠模型及給藥:參照文獻(xiàn)[6]并加以改進(jìn),方法如下:?jiǎn)问止潭ㄐ∈?,?jīng)口將12號(hào)灌胃針插入小鼠食管中下段,緩慢注入0.1N HCl(含0.5%胃蛋白酶)0.3mL,2次/天,共21天。灌注完畢,小鼠無(wú)嘔吐、抽搐等不適。灌鹽組予同等劑量生理鹽水代替,其時(shí)間和方式同灌酸組小鼠相同。
三、標(biāo)本的制備及檢測(cè)
一次抗原激發(fā)后48小時(shí),小鼠摘眼球取血,缺血死亡。
1 外周血的收集:摘取眼球取血,收集于EP管中,立即放置4 ℃冰箱中。4小時(shí)后,以3000rpm離心10min(4 ℃),取上清液分裝入EP管中,存放入-80 ℃冰箱。離心液用ELISA法測(cè)試BRP-39的濃度。
2 支氣管肺泡灌洗液(BALF)收集:將小鼠固定在手術(shù)臺(tái)上,打開(kāi)胸腔,分離氣管,結(jié)扎右主支氣管,于氣管軟骨環(huán)3-4處,插入經(jīng)改良的留置針,于氣管插管處分批緩慢注入共0.8mL的生理鹽水灌洗左肺,留置30秒,再緩慢回抽,共3次,記錄回收的肺泡灌洗液(BALF),計(jì)算回收率,保證回收率80%以上。以3000rpm離心10min(4 ℃)后細(xì)胞沉渣用于細(xì)胞分類計(jì)數(shù),上清液分裝入EP管中,-80 ℃保存。離心液用ELISA法測(cè)試BRP-39的濃度。
四、統(tǒng)計(jì)方法
一、BALF細(xì)胞總數(shù)及分類計(jì)數(shù)
哮喘造模組小鼠(包括單純哮喘組及哮喘灌鹽、哮喘灌酸組)BALF中細(xì)胞總數(shù)較正常對(duì)照組高,嗜酸性粒細(xì)胞、中性粒細(xì)胞和淋巴細(xì)胞的細(xì)胞分類百分比均較對(duì)照組高,以嗜酸性粒細(xì)胞增高最為明顯,具有統(tǒng)計(jì)學(xué)的意義(P<0.05-P<0.01);灌酸組小鼠BALF中細(xì)胞總數(shù)較對(duì)照組高,中性粒細(xì)胞和淋巴細(xì)胞的細(xì)胞分類數(shù)均較對(duì)照組高,但以中性粒細(xì)胞增高最為明顯,具有統(tǒng)計(jì)學(xué)差異(P<0.05-P<0.01),嗜酸性粒細(xì)胞與對(duì)照組比較無(wú)明顯變化。(見(jiàn)表1)。
表1 6組小鼠BALF中的細(xì)胞絕對(duì)計(jì)數(shù)及分類的比較±s)
注:(M%、L%、N%、E%分別代表巨噬細(xì)胞、淋巴細(xì)胞、中性粒細(xì)胞、嗜酸性粒細(xì)胞比例);與正常對(duì)照組相比,*P<0.05;***P<0.001
二、BRP-39濃度變化
各組BALF中的BRP-39濃度比血清中的BRP-39濃度高,以哮喘灌酸組最為明顯;與對(duì)照組比較,除灌鹽組外,其余各組BALF液、血清中BRP-39濃度均明顯升高,且哮喘組較單純灌酸組升高的幅度大,哮喘灌酸組升高尤其明顯;正常組vs灌鹽組,哮喘灌鹽組vs哮喘灌酸組無(wú)統(tǒng)計(jì)學(xué)差異,說(shuō)明食管灌鹽不影響小鼠肺部炎癥反應(yīng)。(見(jiàn)表2)。
表2 6組小鼠BALF液、外周血中BRP-39濃度比較
注:與對(duì)照組比較:*P<0.05;與灌酸組比較:▲P<0.05
三、相關(guān)性分析
實(shí)驗(yàn)各組BALF BRP-39、血BRP-39與BALF中的細(xì)胞總數(shù)呈正相關(guān)(P<0.05-P<0.01);BALF BRP-39、血BRP-39與中性粒細(xì)胞、嗜酸性粒細(xì)胞比例之間亦正相關(guān),余無(wú)明顯相關(guān)性(見(jiàn)表3)。
表3 各組BALF及血BRP-39濃度與BALF中的細(xì)胞絕對(duì)計(jì)數(shù)及分類之間的相關(guān)性
注:*P<0.05,**P<0.01
YKL-40是殼質(zhì)酶家族的一類分泌蛋白,存在于哺乳動(dòng)物中,在人的同系物則稱為YKL-40,在小鼠稱為BRP-39。YKL-40在炎癥細(xì)胞和多種惡性腫瘤細(xì)胞中高度分泌和表達(dá)[10],目前認(rèn)為與細(xì)胞的增殖、分化、凋亡、轉(zhuǎn)移、組織重建和炎癥發(fā)生密切相關(guān),但它真正的生理學(xué)及生物學(xué)功能還不清楚[11]。越來(lái)越多的研究顯示YKL-40參與多種呼吸系統(tǒng)疾病的發(fā)病機(jī)制。Nordenbaek等[12]發(fā)現(xiàn)肺炎患者或菌血癥患者血清中YKL-40濃度比健康人要高,YKL-40參與了中性粒細(xì)胞對(duì)病原微生物的吞噬作用,認(rèn)為其廣泛地參與了人體組織的炎性反應(yīng)。Matsuura[13]等在小鼠實(shí)驗(yàn)中發(fā)現(xiàn)BRP-39可以促進(jìn)巨噬細(xì)胞釋放IL-8、MCP-1、MMP-9,顯示其在慢阻肺慢性氣道炎癥和結(jié)構(gòu)重塑中其重要作用。Lee[14]等多個(gè)研究證實(shí)了YKL-40參與了哮喘和其他過(guò)敏性疾病過(guò)敏性反應(yīng)的多個(gè)階段。在抗原致敏、IgE誘導(dǎo)及刺激樹(shù)突狀細(xì)胞募集和活化已經(jīng)誘導(dǎo)交替性巨噬細(xì)胞的激活中均起到重要的作用??纱碳?shù)突狀細(xì)胞募集和活化、增加細(xì)胞數(shù)量,減少T細(xì)胞凋亡、延長(zhǎng)其存活時(shí)間、增加TH2數(shù)量、增強(qiáng)TH2分化等方面[15]。Tang等[16]研究發(fā)現(xiàn),哮喘患者YKL-40的血漿水平較對(duì)照組明顯升高,且與總IgE水平及外周血嗜酸粒細(xì)胞百分比呈正相關(guān)。Chupp等[17]首次明確闡明哮喘群體肺YKL-40和氣道重塑(上皮下基底膜厚度增加)相關(guān)。這些研究結(jié)果均表明YKL-40參與了多種氣道慢性炎癥性疾病,特別是與過(guò)敏性哮喘的發(fā)病密切相關(guān),但YKL-40是否與GER加重哮喘炎癥反應(yīng)相關(guān),尚未見(jiàn)有相關(guān)報(bào)道。通過(guò)測(cè)試不同造模組血清及BALF液中BRP-39的濃度,以了解BRP-39與食管酸灌注引起小鼠肺部炎癥反應(yīng)及加重哮喘相關(guān)性。
本實(shí)驗(yàn)研究結(jié)果中,BALF比血清中BRP-39的濃度升高更加明顯,這是因?yàn)锽ALF中的細(xì)胞及炎癥因子濃度比血清更能客觀且直接地反映氣道的炎癥狀況。與對(duì)照組比,除灌鹽組外,其余各組特別是哮喘灌酸組,BALF及血清中BRP-39的濃度均明顯升高,且與BALF中的細(xì)胞總數(shù)及中性粒細(xì)胞、嗜酸性粒細(xì)胞呈正相關(guān),因此BRP-39濃度變化能在一定程度上反映氣道炎癥程度,與多次食管酸灌注加重哮喘小鼠氣道內(nèi)的炎癥反應(yīng)相一致。
已有研究證明BRP-39不僅在過(guò)敏性炎癥疾病中促進(jìn)嗜酸粒細(xì)胞的聚焦[17],也參與了中性粒細(xì)胞吞噬病原菌的過(guò)程[12-13],故BRP-39在多次食管酸灌注進(jìn)一步加重哮喘小鼠氣道炎癥的發(fā)病過(guò)程中機(jī)制中可能發(fā)揮著重要作用,為探究哮喘的發(fā)病機(jī)制提供一些不同的研究方向。BRP-39并不是炎癥介質(zhì)或細(xì)胞因子,只是炎癥程度的生物標(biāo)志物,并不能直接導(dǎo)致炎癥,這需要進(jìn)一步弄清BRP-39在炎癥反應(yīng)中的機(jī)制。
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Effect of esophageal acid infusion on airway inflammation and changes of BRP-39 levels in asthmatic mice model
JIALi-ping,CAIZhi-tao,CHENZu-guang,LIUMei-dan,YAOWei-ming.
TheCentralHospitalofHuanggangCity,Huanggang,Hubei438000,China
Objective To observe the influence of airway inflammation by repeating esophageal acid infusion and the relationship between BRP-39 levels and airway inflammation in mice with asthma. Methods A total of 60 male BALB/c mice were randomly divided into six groups (the control group, the salt group, the HCl group, the asthma group, the asthma and salt group, the asthma and HCl group). Asthma model was established by intraperitoneal injection and atomization chicken ovalbumin (OVA). HCL was used to do lower esophageal perfusion to establish GER model. Mice were sacrificed in 24 hours after the last antigen stimulation. The BRP-39 levels in serum and BALF of the mice were measured by enzymelinked immunosorbent assay (ELISA). The total and classification cell numbers in BALF were recorded. Results (1) The total cells, eosinophils, neutrophils and lymphocytes of BALF in the asthma model group (including the asthma group, the asthma and NS group, and the asthma and HCL group) were higher than those in the control group, especially for eosinophils (P<0.05-P<0.01). Compared with the control group, the total cells, neutrophils and lymphocytes in BALF of the HCL group were higher, especially for neutrophils (P<0.05-P<0.01). There was no statistically difference in Eosinophilic cells between the HCL group and the control group. (2) Compared with the normal group, in addition to the salt group, BRP-39 concentrations in BALF fluid and blood increased in the other groups (P<0.05), especially in the asthma and HCL group. And there was a positive correlation between BRP-39 levels and the number of BALF, neutrophils, eosinophils (P<0.05-P<0.01). Conclusion Repeated?esophageal acid?perfusion?can cause?inflammation in lung, and BRP-39 levels in serum and BALF increase. GER can cause or aggravate asthma, which may be associated with BRP-39 levels.
mice; asthma; gastroesophageal reflux; BRP-39
10.3969/j.issn.1009-6663.2017.09.010
廣東醫(yī)學(xué)院博士啟動(dòng)項(xiàng)目(No.XB0816);廣東醫(yī)學(xué)院附屬醫(yī)院博士啟動(dòng)項(xiàng)目(No.10301B010012)
1. 438000 湖北 黃岡,黃岡市中心醫(yī)院呼吸內(nèi)科 2. 524001 廣東 湛江,廣東醫(yī)科大學(xué)附屬醫(yī)院呼吸內(nèi)科
姚衛(wèi)民,E-mail:490296443@qq.com
2016-12-12]