鼠李糖乳酸杆菌LG_A对鸡小肠上皮细胞β-防御素-9基因表达的影响  

Effect of Lactobacillus rhamnosus LGA on β-defensin 9 Expression in Cultured Chicken Small Intestinal Epithelial Cells

作　　者：黎观红[1] 洪智敏[1] 贾永杰[1] 易中华[1] 瞿明仁[1] 刘思国[2] 

机构地区：[1]江西农业大学动物科技学院,南昌330045 [2]中国农业科学院哈尔滨兽医研究所,哈尔滨150001

出　　处：《畜牧兽医学报》2012年第4期634-641,共8页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：国家自然科学基金项目(30800791);江西省青年科学家培养对象计划项目(赣科发计字[2010]209号)

摘　　要：本研究旨在研究益生性鼠李糖乳酸杆菌LGA对体外培养的鸡小肠上皮细胞β-防御素-9(AvBD9)表达的调节作用。选用鼠李糖乳酸杆菌LGA对体外培养的鸡小肠上皮细胞进行剂量依赖性及时间依赖性刺激实验,利用实时荧光定量PCR(fluorescence quantitative PCR,FQ-PCR)从mRNA水平研究刺激后上皮细胞AvBD9基因表达水平的差异。结果表明,不同浓度(2×105、2×106、2×107 cfu.mL-1)鼠李糖乳酸杆菌LGA均能上调AvBD9mRNA的表达,且在不同细菌浓度之间AvBD9mRNA的表达存在差异。热灭活鼠李糖乳杆菌LGA亦能上调AvBD9基因表达,且上调值显著高于活菌(P<0.05)。鼠李糖乳杆菌LGA刺激上皮细胞后AvBD9表达存在时间依赖关系,12h时AvBD9的表达达到峰值。Western blot检测结果显示,鼠李糖乳杆菌LGA刺激后的上皮细胞培养上清中存在AvBD9蛋白表达,表明AvBD9蛋白可以分泌到细胞外而发挥其生物学功能。益生性鼠李糖乳酸杆菌LGA与鸡肠道上皮细胞的相互作用过程中,鼠李糖乳酸杆菌LGA能够促进上皮细胞抗菌肽β-防御素-9的表达。本研究结果提示益生性乳杆菌可能通过促进肠道上皮抗菌肽的表达而发挥其益生作用。This study aimed to investigate the effect of probiotic Lactobacillus rhamnosus LGA（L.rhamnosus LGA） on the β-defensin 9（AvBD9） expression in cultured chicken small intestinal epithelial cells.L.rhamnosus LGA was selected to examine the time-and dose-response of AvBD9 gene expression upon stimulation of chicken intestinal small epithelial cells with L.rhamnosus LGA.The AvBD9 mRNA expression was determined by fluorescence quantitative PCR（FQ-PCR）.The results showed that AvBD9 expression was upregulated by stimulation of L.rhamnosus LGA at different concentrations（2×10^5,2×10^6,2×10^7 cfu·mL^-1）,and expression difference was observed between treatments at three bacterial concentrations.Heat-inactivated L.rhamnosus LGA also stimulated the expression of AvBD9,and showed stronger induction response than live bacteria（P〈0.05）.The L.rhamnosus LGA promoted AvBD9 mRNA transcription in time-dependent manner.The AvBD9 mRNA expression peaked at 12 h of incubation upon treatment of epithelial cells with lactobacillus.AvBD9 peptide was detected by Western blot in the supernatants of cultured epithelial cells treated with L.rhamnosus LGA,indicating that AvBD9 peptide releases into extracellular medium and exerts its biological actions.Probiotic L.rhamnosus LGA stimulates AvBD9 expression in the epithelial cells of chicken small intestine during lactobacillus-epithelial cell interaction.This study reveals the new possible functional mechanism by which the probiotic Lactobacilli exert their beneficial effects to the host through the antimicrobial peptide expression in the small intestinal epithelium.

关 键 词：β-防御素-9 鸡小肠上皮细胞 鼠李糖乳酸杆菌LGA 荧光定量PCR 

分 类 号：S831.1[农业科学—畜牧学]