鄧怡林,于合國,施敏,石翠翠,范建高,李光明
·肝衰竭·
Orionin對急性肝衰竭小鼠的保護(hù)作用及其對肝組織細(xì)胞因子水平的影響*
鄧怡林,于合國,施敏,石翠翠,范建高,李光明
目的探討冬凌草甲素(Oridonin)對脂多糖/D-氨基半乳糖氨(LPS/D-Gal)聯(lián)合誘導(dǎo)的急性肝衰竭(ALF)小鼠的保護(hù)作用及其對肝組織細(xì)胞因子水平的影響。方法取150只小鼠,隨機(jī)分成5組,每組30只。采用LPS/D-Gal腹腔注射建立小鼠ALF模型,設(shè)生理鹽水對照組、Oridonin對照組、LPS/D-Gal誘導(dǎo)模型組和LPS/D-Gal處理及不同劑量Oridonin干預(yù)組。采用Real-time PCR法檢測肝組織腫瘤壞死因子-α(TNF-α)、白細(xì)胞介素(IL)-1α、IL-1β和IL-6 mRNA水平。結(jié)果模型組小鼠48 h存活率為0.0%(0/30),而兩個Oridonin干預(yù)組小鼠48 h存活率分別提高至64.5%(19/30)和80.6%(24/30,P<0.01);組織病理學(xué)檢查顯示模型組小鼠肝細(xì)胞呈大塊或/和亞大塊壞死,肝小葉結(jié)構(gòu)消失,殘存肝細(xì)胞腫脹、空泡變性,肝竇腫脹充血,炎細(xì)胞浸潤。Oridonin干預(yù)組小鼠肝細(xì)胞壞死、空泡變性和炎細(xì)胞浸潤等較模型組有明顯的改善;模型組小鼠血清ALT和AST水平分別為(345.3± 54.1)U/L和(500.2±53.5)U/L,明顯高于對照組的[(42.3±0.6)U/L和(117.1±9.8)U/L,P<0.01],兩個Oridonin干預(yù)組分別為(303.9±39.5)U/L和(340.6±2.8)U/L及[(130.2±38.3)U/L和(209.8±36.2)U/L,P<0.05];模型組小鼠肝組織TNF-α、IL-1α、IL-1β和IL-6 mRNA水平顯著高于正常對照組(P<0.01),而兩個Oridonin干預(yù)組肝組織TNF-α、IL-1α、IL-1β和IL-6 mRNA水平顯著低于模型組(P<0.01)。結(jié)論Oridonin對LPS/D-Gal誘導(dǎo)的ALF小鼠具有顯著的保護(hù)作用,其作用機(jī)制可能與降低肝組織細(xì)胞因子水平有關(guān)。
急性肝衰竭;脂多糖;D-氨基半乳糖氨;冬凌草甲素;細(xì)胞因子;小鼠
急性肝衰竭(Acute liver failure,ALF)病情兇險,死亡率高,目前尚無有效防治方法[1]。因此,探尋能改善ALF預(yù)后的治療新策略具有重要的臨床意義。ALF病情進(jìn)展與炎性細(xì)胞因子過度釋放及由此介導(dǎo)的肝細(xì)胞凋亡和壞死密切相關(guān)[1-3]。冬凌草甲素(oridonin)是從中藥冬凌草中分離出來的活性雙萜類化合物,具有廣泛的抗腫瘤和抗炎等生物活性[4-7]?;贏LF是一種炎癥相關(guān)性疾病,oridonin具有廣泛強(qiáng)大的抗炎效應(yīng),提示oridonin可能對ALF具有保護(hù)作用。本研究以脂多糖/D-氨基半乳糖氨(Lipopolysaccharide/D-galactosamine,LPS/D-Gal)誘導(dǎo)小鼠ALF為模型,探討oridonin的保護(hù)作用,并初步探索其保護(hù)作用是否與抑制肝組織細(xì)胞因子的分泌水平有關(guān)。
1.1 動物、試劑與藥物6~8周齡,雌性SPF級,體質(zhì)量為20~22 g的C57/BL6小鼠購自中國科學(xué)院上海生命科學(xué)研究院,在清潔級動物實驗中心喂養(yǎng)(標(biāo)準(zhǔn)動物飼料及飲水,環(huán)境溫度為21±2℃,12 h的明暗交替光照時間)。所有動物實驗均符合本校動物倫理委員會的有關(guān)規(guī)定。D-Gal和LPS(E. Coli,菌株O111:B4)購自美國Sigma公司。Oridonin購自美國Selleck公司。蘇木素-伊紅染色試劑盒購自江蘇凱基生物技術(shù)股份有限公司。ReverTra Ace qPCR RT Kit購自日本Toyobo公司,SYBR@ Green Real-time PCR Master Mix購自上海ExCell Bio公司。
1.2 ALF模型的建立取150只小鼠,隨機(jī)分成5組,每組30只。a組(正常對照組):給予生理鹽水0.5 ml腹腔注射,1 h后注射同等體積的生理鹽水;b組(藥物對照組):給予Oridonin(將oridonin溶于生理鹽水,0.2 mg/只)0.5 ml腹腔注射,1 h后注射同等體積的生理鹽水;c組(模型組):給予LPS(40 μg/只)/D-Gal(5 mg/只)/生理鹽水0.5 ml腹腔注射,1 h后注射同等體積的LPS/D-Gal混合溶液;d組和e組(藥物干預(yù)組):給予Oridonin(0.2 mg/只)/LPS(40 μg/只)/D-Gal(5 mg/只),其中d組給予Oridonin(0.2 mg/只)0.5 ml腹腔注射,1 h后給予同等體積的LPS/D-Gal混合溶液腹腔注射,e組給予Oridonin 0.5 ml腹腔注射,1次/4 d,共3次,最后一次在給藥后1 h給予同等體積的LPS/D-Gal混合溶液腹腔注射。觀察并記錄各組小鼠存活情況,1次/6 h,計算小鼠48 h存活率。另取25只小鼠,隨機(jī)分成5組,每組5只,分組和藥物處理方法同上。在腹腔注射LPS/D-Gal后6 h,經(jīng)眼球采血,分離血清,保存于-80℃,備檢。取肝組織,浸泡于4%多聚甲醛溶液中,經(jīng)過常規(guī)脫水、浸蠟、包埋,制成5μM切片,行HE染色。另取肝組織經(jīng)液氮速凍后,置于-80℃冰箱保存,備檢。
1.3 血清ALT和AST水平檢測使用日立7180全自動血生化分析儀檢測。
1.4 肝組織細(xì)胞因子mRNA水平檢測采用RT-PCR法,以Trizol法提取肝組織RNA,經(jīng)紫外分光光度計測定RNA純度,取吸光度A260/A280為1.8~2.0的RNA用于逆轉(zhuǎn)錄,采用Real-time PCR試劑盒行PCR擴(kuò)增,每個反應(yīng)體系共20μl,包括DNA模板(10 ng/μl)1.4μl,SYBR 10μl,引物1.6μl(10μM)和ddH2O 7μl。反應(yīng)條件為95℃預(yù)變性10 min,95℃變性20 s,58℃退火30 s,72℃延伸25 s,40個循環(huán)。以GAPDH為內(nèi)參照,運用2-△△CT法分析結(jié)果。所有引物均由美國Thermo Fisher Scientific公司合成,其序列分別為:TNF-α:正義鏈,5’-CTCCCAGGTATATGGGCT CA-3’,反義鏈:5’-CCA GGT TCT CTT CAA GGG AC-3’;IL-1α:正義鏈,5’-AGT ATC AGC AAC GTC AAG CAA-3’,反義鏈:5’-TCC AGA TCA TGG GTT ATG GAC TG-3’;IL-1β:正義鏈,5’-GAAATGCCACCTTTTGACAGT G-3’,反義鏈:5’-TGG ATG CTC TCA TCA GGA CAG-3’;IL-6:正義鏈,5’-TAG TCC TTC CTA CCC CAA TTT CC-3’,反義鏈:5’-TTG GTC CTT AGC CAC TCC TTC-3’;GAPDH:正義鏈,5’-TCC AAG GAG TAA GAA ACC CTG GAC-3’,反義鏈,5’-GTTATTATGGGGGTCTGGGAT GG-3’。
1.5 統(tǒng)計學(xué)處理應(yīng)用GraphPad Prism 6.0行統(tǒng)計學(xué)分析,計量資料以±s表示,組間比較采取獨立樣本t檢驗,兩個和兩個以上樣本率的比較采用卡方檢驗。P<0.05和P<0.01分別表示差異具有顯著性和非常顯著性統(tǒng)計學(xué)意義。
2.1 Oridonin可顯著提高ALF小鼠存活率在LPS/D-Gal刺激后,模型組小鼠48 h存活率為0.0%(0/30);經(jīng)Oridonin干預(yù)的d組和e組小鼠48h存活率分別提高至64.5%(19/30)和80.6%(24/30,P<0.01,圖1),表明Oridonin可明顯提高ALF小鼠的存活率。
圖1 各組小鼠存活率比較正常對照組及藥物對照組小鼠48 h存活率為100%(30/30);在LPS/D-Gal刺激后,模型組小鼠48 h存活率為0.0%(0/30),經(jīng)Oridonin干預(yù)的d組和e組小鼠48 h存活率分別提高至64.5%(19/30)和80.6%(24/30)
2.2 Oridonin顯著改善ALF小鼠肝組織損傷正常對照組及藥物對照組肝組織細(xì)胞及肝小葉結(jié)構(gòu)完整;在LPS/D-Gal處理6 h后,模型組小鼠肝組織呈大塊或/和亞大塊壞死,小葉結(jié)構(gòu)消失,殘存肝細(xì)胞腫脹、空泡變性,肝竇腫脹充血,炎細(xì)胞浸潤;Oridonin干預(yù)組小鼠肝細(xì)胞壞死、空泡變性及炎細(xì)胞浸潤等較模型組有明顯的改善(圖2)。
圖2 肝組織病理學(xué)表現(xiàn)(HE,200×)a:正常對照組,b:藥物對照組;c:模型組;d和e:藥物干預(yù)組
2.3 各組小鼠血清ALT和AST水平比較在LPS/D-Gal處理6 h后,模型組小鼠血清ALT和AST水平分別為(345.3±54.1)U/L和(500.2± 53.5)U/L,顯著高于對照組的(42.3±0.6)U/L和(117.1±9.8)U/L,P<0.01);Oridonin干預(yù)的d組血清ALT和AST水平分別下降為(303.9±39.5)U/L和(340.6±2.8)U/L,Oridonin干預(yù)的e組血清ALT和AST水平分別顯著下降為(130.2±38.3)U/L和(209.8±36.2)U/L(P<0.05,圖3)。
圖3 各組血清轉(zhuǎn)氨酶水平變化比較與正常對照組比,##P<0.01;與模型組比,*P<0.01
2.4 各組小鼠肝組織炎癥因子mRNA水平比較見圖4,提示Oridonin對LPS/D-Gal誘導(dǎo)的小鼠肝組織炎癥因子水平具有顯著的阻抑作用。
圖4 肝組織細(xì)胞因子mRNA水平變化與正常對照組比,##P<0.01;與模型組比,*P<0.01
LPS/D-Gal誘導(dǎo)的ALF與臨床ALF病理過程相似,是研究ALF的經(jīng)典動物模型[11-13],也是篩選ALF治療新藥的重要手段。因此,利用此動物模型,我們探討了Oridonin對ALF小鼠的保護(hù)作用及其可能的機(jī)制。
我們選擇在LPS/D-Gal刺激前,給予Oridonin預(yù)處理[14-18]。結(jié)果顯示,給予Oridonin預(yù)處理可明顯提高ALF小鼠48 h存活率,表明Oridonin對ALF具有顯著的保護(hù)作用。我們進(jìn)一步研究了LPS/D-Gal處理6 h后模型組小鼠肝組織呈大塊和/或亞大塊壞死伴血清ALT/AST顯著升高,提示小鼠ALF模型構(gòu)建成功,Oridonin干預(yù)組小鼠不僅血清ALT/AST水平明顯降低,而且肝細(xì)胞變性、壞死及炎性細(xì)胞浸潤也顯著減輕,提示Oridonin對LPS/D-Gal誘導(dǎo)的ALF小鼠具有顯著的保護(hù)作用。
ALF發(fā)病機(jī)制與損傷因素誘導(dǎo)的炎性細(xì)胞因子過度釋放及其引起的肝組織急性炎癥反應(yīng)密切相關(guān)[12,15,19]。有研究報道,Oridonin可以抑制LPS和β-淀粉樣蛋白刺激的神經(jīng)小膠質(zhì)細(xì)胞一氧化氮(NO)、TNF-α和IL-6等炎癥因子釋放,同時伴有對NF-κB信號通路的抑制[7,20],說明Oridonin可能對炎癥相關(guān)性疾病具有保護(hù)作用。為了探討Oridonin對ALF小鼠的保護(hù)機(jī)制,我們評估了在ALF發(fā)病中起關(guān)鍵作用的促炎細(xì)胞因子TNF-α、IL-1和IL-6基因水平變化。研究發(fā)現(xiàn)在LPS/D-Gal誘導(dǎo)的ALF小鼠肝組織TNF-α、IL-1α、IL-β和IL-6 mRNA水平顯著上調(diào),Oriodnin預(yù)處理則可顯著抑制上述炎癥因子的上調(diào),提示Oriodnin對ALF的保護(hù)作用可能與抑制肝臟炎癥反應(yīng)有關(guān)。
我們的研究首次證實Oridonin對ALF具有顯著保護(hù)作用,其機(jī)制可能與抑制肝臟炎癥反應(yīng)有關(guān),預(yù)示Oridonin在ALF臨床干預(yù)方面可能具有潛在的應(yīng)用價值。
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(收稿:2016-10-14)
(本文編輯:陳從新)
Effect of oridonin on hepatic cytokine levels in mice with LPS/D-Gal-induced acute liver failure
Deng Yilin,Yu Heguo,Shi Min,et al.Department of Gastroenterology,Xinhua Hospital Affiliated to Jiaotong University School of Medicine,Shanghai 200092,China
ObjectiveTo investigate the effectoforidonin on hepatic cytokinelevelsinmicewith polysaccharide(LPS)/D-galactosamine(D-Gal)-induced acute liver failure.Methods150 mice were randomly divided into five groups(30 in each group),e.g.,normal,oridonin control,model,oridonin-intervened,and oridoninintervened for 12 days.ALF model was established in C57BL/6 mice by intraperitoneal injection of LPS/D-Gal. ResultsThe 48 h lethality rate in LPS/D-Gal-induced group reached an extremely high level of 100%. However,the 48 h survival rates in two oridonin-intervened groups were 64.5%(19/30)and 80.6%(24/30,P<0.01);The damage in liver tissues was ameliorated in mice pretreatedwith oridonin as compared with that in the model group;Serum ALT and AST levels in model group were(345.3±54.1)U/L and(500.2±53.5)u/L,significantly higher than those in control group[(42.3±0.6)U/L and(117.1±9.8)U/L,P<0.01]or in oridonin-treated group[(303.9± 39.5)U/L and(340.6±2.8)U/L or[(130.2±38.3)U/L and(209.8±36.2)U/L,P<0.05];Administration of oridonin in mice with LPS/D-Gal-induced ALF significantly decreased mRNA levels of hepatic TNF-α,IL-1α,IL-1β and IL-6 compared with in model group(P<0.01).ConclusionOridonin has a protective effect on mice with LPS/DGal-induced ALF,and the mechanism might be related to inhibition of hepatic cytokine activities.
Acute liver failure;Lipopolysaccharide;D-galactosamine;Oridonin;Cytokines;Mice
10.3969/j.issn.1672-5069.2017.03.010
國家自然科學(xué)基金資助項目(編號:81400631/81570549)
200092上海市上海交通大學(xué)醫(yī)學(xué)院附屬新華醫(yī)院消化內(nèi)科(鄧怡林,石翠翠,范建高,李光明);同仁醫(yī)院消化內(nèi)科(施敏);上海市計劃生育科學(xué)研究所(于合國,刁華)
鄧怡林,女,25,碩士研究生。主要從事肝損傷及肝纖維化的防治研究。E-mail:yilindeng1991@163.com
李光明,E-mail:ligm68@126.com