重组人乳铁蛋白对幽门螺杆菌抑菌作用的实验研究

摘要

目的：评估重组人乳铁蛋白（rhLF）对幽门螺杆菌（H ．pylori）的抑菌作用及其对细胞毒素相关蛋白A（CagA）、尿素酶（Ure）和胃黏膜白细胞介素8（IL‐8）的影响。方法测定最低抑菌浓度（MIC）和不同药物浓度对 H ．pylori增殖的影响。通过实时定量PCT和Western blot检测rhLF对 H ．pylori CagA和Ure的mRNA和蛋白表达的影响。动物实验，144只BABL／c小鼠，分为4组，标准三联＋rhLF组（A组）、rhLF组（B组）、标准三联组（C组）、生理盐水组（D组），组织病理学苏木素‐伊红（HE）染色观察不同分组间胃黏膜炎性反应，ELISA法检测各组胃组织IL‐8水平。结果 MIC为0．5 mg／mL ，且rhLF抑制细菌生长增殖呈现浓度依赖性过程。rhLF能降低H ．pylori主要毒力因子CagA、Ure mRNA和蛋白的表达。A组胃黏膜组织炎症积分和匀浆液IL‐8水平与B、C、D组比较，差异均有统计学意义（P＜0．05）。结论 rhLF抑制H ．pylori生长及增殖，并不同程度抑制H ． pylori主要毒力因子CagA、Ure mRNA及蛋白的表达，削弱该菌的致病性，同时降低小鼠胃黏膜IL‐8水平，减轻H ．pylori相关性胃黏膜炎性反应。%Objective To evaluate the bacteriostatic effect of recombinant human lactoferrin(rhLF) on Helicobacter(H .) py‐lori and its influence on CagA ,Ure and gastric mucosal IL‐8 .Methods The minimum inhibitory concentration(MIC)and the influ‐ence of different drug concentrations on the proliferation of H .pylori were detected .The effects of rhLF on the mRNA and protein expressions of CagA and Ure in H .pylori were detected by RT‐PCR and Western blot ,respectively .The animal study :Balb/c mice were adopted and assigned randomly into four groups ,including the standard triple+rhLF(group A) ,rhLF(group B) ,standard tri‐ple(group C) and normal saline(group D) .The histopathological HE staining was used to observe the gastric inflammation and ELISA was used to detect the IL‐8 level of gastric tissue in each group .Results MIC was 0 .5 mg/mL ,moreover rhLF inhibited the bacterial growth and proliferation with a concentration‐dependent manner .rhLF could reduce the expression of H .pylori major viru‐lence factor CagA ,mRNA and protein of Ure .Comparing the group A with the group B ,C and D ,the gastric mucosal inflammation score and the IL‐8 levels of gastric tissue homogenates had statistically significant differences(P<0 .05) .Conclusion rhLF inhibits the growth and proliferation of H .pylori ,moreover inhibit the expression of major virulence factor CagA in H .pylori ,mRNA and protein of Ure in different degrees ,weakens its pathogenicity ,meanwhile reduces the IL‐8 level in mice gastric mucosa ,and allevi‐ates H .pylori related gastric mucosal inflammatory response .