The Gastric Biology of Helicobacter Pylori

幽门螺杆菌的胃生物学

• 批准号: 7901977
• 负责人: George Sachs
• 金额: $ 8.09万
• 依托单位: BRENTWOOD BIOMEDICAL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7901977
• 关键词: Acclimatization; Acids; Affect; Amoxicillin; Antibiotics; Apoenzymes; Bacteria; Binding; Biology; Buffers; Carbon Dioxide; Cell Wall; Cell division; Complex; Data; Down-Regulation; Fluorescence; Future; Gel; Gene Expression; Gene Expression Profile; Generations; Genes; Gerbils; Growth; Half-Life; Helicobacter Infections; Helicobacter pylori; In Vitro; Infection; Lead; Measures; Mediating; Membrane; Membrane Protein Traffic; Mus; Omeprazole; Operon; Organism; Peptic Ulcer; Phosphotransferases; Physiological; Physiology; Play; Protein Biosynthesis; Proteins; Pump; Regulation; Regulon; Research; Resistance; Risk; Role; Screening procedure; Signal Transduction; Stomach; System; Testing; Therapeutic; Time; Transcriptional Regulation; Up-Regulation; Urea; Urease; Yeasts; comparative; in vivo; inhibitor/antagonist; insight; malignant stomach neoplasm; mutant; pathogen; periplasm; promoter; protein-histidine kinase; public health relevance; response; sensor; therapeutic target; trafficking; yeast two hybrid system

DESCRIPTION (provided by applicant): The aims are to investigate the gastric physiology of the gastric pathogen Helicobacter pylori. Specific Aims: (A). Identify the acid response regulon and signaling system of the cytoplasmic pH sensor. HP0244 is a previously unsuspected sensor of cytoplasmic pH. Using transcriptome analysis after pH 2.5 incubation, the HP0244, HP0703 independent, regulon will be identified to separate periplasmic (HP0165) from cytoplasmic pH) regulation and confirmed by qPCR; (B) Identify colonization dependent gene expression and evaluate pH control of their expression by comparative transcriptome analysis of H. pylori from infected gerbils with and without acid suppression. Transcriptome analysis of H. pylori infecting the gerbil stomach compared to in vitro cultured H. pylori showed a greater up-regulation of genes encoding proteins involved in acid acclimation than at pH 4.5 in vitro, likely reflecting a pH <4.5 in the niche of the colonizing organisms. Cell division, wall and protein biosynthesis genes were also increased. Preliminary data show that acid inhibition by a PPI reduces expression of the former group to the level found at pH 4.5 in vitro but augments expression of the latter three groups of growth-related genes, this may explain the need for a combination of a PPI with growth-dependent antibiotics for triple therapy. These data may lead to dual therapy with a long acting PPI + amoxicillin; (C) Investigate pH-induced activation and trafficking of a urease complex and other proteins to UreI on the inner membrane and determine whether this is regulated by HP0165 or HP0244 The expression of urease by H. pylori (~10% of total protein) is essential for gastric infections. However, at neutral pH, only 1/3rd of urease is active, 2/3rd is present as inactive apoenzyme. pH-dependent activation of the apoenzyme would provide a more rapid response to acid than de novo synthesis. Preliminary results suggest that there is activation and translocation of urease at acidic pH that is dependent on HP0165. UreI serves as the membrane anchor for the pH- dependent relocation of urease to the inner membrane and this is required for activation of apourease. This research may provide new leads for improvement eradication therapy thereby decreasing the risk of peptic ulcer disease and gastric cancer. PUBLIC HEALTH RELEVANCE: Helicobacter pylori is responsible for peptic ulcers and a fortyfold increased risk of gastric cancer. We shall analyze the physiology of H. pylori in the stomach by investigating signaling systems for genes regulated by gastric pH and the role of urease trafficking and activation in infection. A better understanding of effects of acid inhibition on H. pylori may allow improvement or replacement of triple therapy for eradication.

描述（由申请人提供）：目的是研究胃部病原体幽门螺杆菌的胃生理学。具体目标：(A)。识别细胞质 p​​H 传感器的酸反应调节子和信号系统。 HP0244 是一种以前未被怀疑的细胞质 p​​H 传感器。在 pH 2.5 孵育后使用转录组分析，将鉴定 HP0244、HP0703 独立调节子，以将周质 (HP0165) 与细胞质 p​​H) 调节分开，并通过 qPCR 进行确认； (B) 通过对感染沙鼠的幽门螺杆菌进行比较转录组分析（有和没有酸抑制），鉴定定植依赖性基因表达并评估其表达的 pH 控制。与体外培养的幽门螺杆菌相比，感染沙鼠胃的幽门螺杆菌的转录组分析表明，与体外 pH 4.5 相比，编码参与酸适应的蛋白质的基因上调更大，这可能反映了环境中 pH <4.​​5 的情况。定殖生物。细胞分裂、壁和蛋白质生物合成基因也增加。初步数据表明，PPI 的酸抑制可将前一组的表达降低至体外 pH 4.5 时的水平，但会增强后三组生长相关基因的表达，这可能解释了将 PPI 与用于三联疗法的生长依赖性抗生素。这些数据可能导致长效 PPI + 阿莫西林的双重治疗； (C) 研究 pH 诱导的脲酶复合物和其他蛋白质向内膜上的 UreI 的激活和运输，并确定这是否受 HP0165 或 HP0244 调节 幽门螺杆菌脲酶的表达（约占总蛋白质的 10%）是对于胃部感染至关重要。然而，在中性pH下，只有1/3的脲酶具有活性，2/3作为无活性的脱辅基酶存在。脱辅基酶的 pH 依赖性激活将提供比从头合成更快的酸响应。初步结果表明，在酸性 pH 条件下，脲酶的激活和易位取决于 HP0165。 UreI 充当膜锚，用于将脲酶依赖于 pH 值重新定位到内膜，这是激活 apourease 所必需的。这项研究可能为改善根除治疗提供新的线索，从而降低消化性溃疡病和胃癌的风险。 公众健康相关性：幽门螺杆菌会导致消化性溃疡，并使患胃癌的风险增加四十倍。我们将通过研究胃 pH 调节基因的信号系统以及尿素酶运输和激活在感染中的作用来分析胃中幽门螺杆菌的生理学。更好地了解酸抑制对幽门螺杆菌的影响可能有助于改进或替代根除三联疗法。