Huang Chun-Hao, Chiou Shyh-Horng
Chun-Hao Huang, Shyh-Horng Chiou, Quantitative Proteomics Center and Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
World J Gastroenterol. 2014 Feb 14;20(6):1529-36. doi: 10.3748/wjg.v20.i6.1529.
The development of gastrointestinal diseases has been found to be associated with Helicobacter pylori (H. pylori) infection and various biochemical stresses in stomach and intestine. These stresses, such as oxidative, osmotic and acid stresses, may bring about bi-directional effects on both hosts and H. pylori, leading to changes of protein expression in their proteomes. Therefore, proteins differentially expressed in H. pylori under various stresses not only reflect gastrointestinal environment but also provide useful biomarkers for disease diagnosis and prognosis. In this regard, proteomic technology is an ideal tool to identify potential biomarkers as it can systematically monitor proteins and protein variation on a large scale of cell's translational landscape, permitting in-depth analyses of host and pathogen interactions. By performing two-dimensional polyacrylamide gel electrophoresis (2-DE) followed by liquid chromatography-nanoESI-mass spectrometry (nanoLC-MS/MS), we have successfully pinpointed alkylhydroperoxide reductase (AhpC), neutrophil-activating protein and non-heme iron-binding ferritin as three prospective biomarkers showing up-regulation in H. pylori under oxidative, osmotic and acid stresses, respectively. Further biochemical characterization reveals that various environmental stresses can induce protein structure change and functional conversion in the identified biomarkers. Especially salient is the antioxidant enzyme AhpC, an abundant antioxidant protein present in H. pylori. It switches from a peroxide reductase of low-molecular-weight (LMW) oligomers to a molecular chaperone of high-molecular-weight (HMW) complexes under oxidative stress. Different seropositivy responses against LMW or HMW AhpC in H. pylori-infected patients faithfully match the disease progression from disease-free healthy persons to patients with gastric ulcer and cancer. These results has established AhpC of H. pylori as a promising diagnostic marker for gastrointestinal maladies, and highlight the utility of clinical proteomics for identifying disease biomarkers that can be uniquely applied to disease-oriented translational medicine.
已发现胃肠道疾病的发展与幽门螺杆菌（H. pylori）感染以及胃肠道中的各种生化应激有关。这些应激，如氧化应激、渗透应激和酸应激，可能对宿主和幽门螺杆菌产生双向影响，导致其蛋白质组中蛋白质表达的变化。因此，在各种应激条件下幽门螺杆菌中差异表达的蛋白质不仅反映了胃肠道环境，还为疾病诊断和预后提供了有用的生物标志物。在这方面，蛋白质组学技术是识别潜在生物标志物的理想工具，因为它可以系统地大规模监测细胞翻译景观中的蛋白质和蛋白质变异，从而深入分析宿主与病原体的相互作用。通过进行二维聚丙烯酰胺凝胶电泳（2-DE），随后进行液相色谱-纳升电喷雾质谱分析（nanoLC-MS/MS），我们成功地确定了烷基过氧化氢还原酶（AhpC）、中性粒细胞激活蛋白和非血红素铁结合铁蛋白为三种潜在的生物标志物，它们分别在氧化应激、渗透应激和酸应激下在幽门螺杆菌中上调。进一步的生化特征表明，各种环境应激可诱导已识别生物标志物的蛋白质结构变化和功能转换。特别突出的是抗氧化酶AhpC，它是幽门螺杆菌中一种丰富的抗氧化蛋白。在氧化应激下，它从低分子量（LMW）寡聚体的过氧化物还原酶转变为高分子量（HMW）复合物的分子伴侣。幽门螺杆菌感染患者对LMW或HMW AhpC的不同血清阳性反应与从无病健康人到胃溃疡和癌症患者的疾病进展忠实地匹配。这些结果确立了幽门螺杆菌的AhpC作为胃肠道疾病有前景的诊断标志物，并突出了临床蛋白质组学在识别可独特应用于疾病导向转化医学的疾病生物标志物方面的效用。
