AIDS Related Oral Candidiasis: Drugs, Sterols, and Fungal Cells

艾滋病相关的口腔念珠菌病：药物、甾醇和真菌细胞

• 批准号: 7361366
• 负责人: Theodore C. White
• 金额: $ 40.03万
• 依托单位: SEATTLE BIOMEDICAL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-02-01 至 2011-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7361366
• 关键词: Acquired Immunodeficiency Syndrome; Active Biological Transport; Affect; Anabolism; Antifungal Agents; Antifungal Therapy; Area; Azole resistance; Azoles; Biochemical; Biological Assay; Candida albicans; Cell Communication; Cell Cycle; Cell membrane; Cell surface; Cells; Clinical; Complex; Condition; Cues; Data; Diagnosis; Drug Interactions; Effectiveness; Environment; Environmental Risk Factor; Enzymes; Ergosterol; Fluconazole; Fungal Components; Future; Gene Expression; Genes; Goals; Immune; In Vitro; Indium-111; Lead; Mediating; Messenger RNA; Metabolism; Mycoses; Nitrogen; Oral; Oral candidiasis; Oxygen; Patients; Pharmaceutical Preparations; Point Mutation; Poison; Population; Predisposition; Prevention; Probability; Process; Protein Overexpression; Regulation; Research; Research Personnel; Resistance; Resistance development; Resistance to infection; Source; Standards of Weights and Measures; Sterol Biosynthesis Pathway; Sterols; Testing; Transcriptional Regulation; Yeasts; clinically significant; efflux pump; improved; insight; resistance mechanism; response; transcription factor; uptake

The pathogenic yeast Candida albicans (Ca) is a major cause of fungal infections in immune- compromised populations including AIDS patients. It is usually treated with antifungal drugs, most commonly the azole fluconazole which is used extensively in AIDS patients. In these patients, there is a significant probability that azole resistance will develop. Using oral resistant isolates from AIDS patients, major mechanisms of resistance have been identified including alterations in ERG11 (a gene encoding an enzyme in ergosterol biosynthesis and target of the azoles) and increased expression of efflux pumps. Ergosterol is the major sterol in the fungal plasma membrane; and its biosynthesis is the target for azoles and many other antifungals The interaction of fungal cells with azoles is a complex process. Specific aspects of metabolism and the environment influence drug/cell interactions in vitro and have the potential to be important clinically. The Overall Goal of this research is to understand how a fungal cell responds to azoles. This proposal investigates import, subsequent regulation of sterols by the UPC2 transcription factor, and the influence of environmental factors on the cellular response to drugs. The Specific Aims of this proposal are: 1. To characterize fluconazole import into the fungal cell. Azole import is important to the cell/drug interaction; it may be mediated by passive or active transport; and it has not been studied previously. 2. To analyze the transcriptional regulation of UPC2. Once within the cell, azoles inhibit Erg 11 p, altering sterol levels, and activating the UPC2 transcription factor, which regulates sterol biosynthesis and uptake. Regulation of the UPC2 gene will be analyzed to understand how changes in sterol metabolism, including uptake and biosynthesis are correlated with expression of UPC2. 3. To characterize the effect of specific environmental factors on drug susceptibility and the cell surface. Environmental factors, including pH, oxygen levels, nitrogen sources, and exogenous sterols, will be analyzed for their effect on the drug susceptibility and the cell surface, using microbiological, biochemical and gene expression approaches. 4. To characterize clinical isolates for alterations in sterol metabolism. The known mechanisms of resistance do not apply to many resistant strains. This aim will assay import, UPC2 regulation, and response to environmental factors to identify possible new resistance mechanisms in these isolates. Understanding the interactions between azoles and fungal cells is a clinically significant issue, with the potential for improving diagnosis, treatment and prevention of fungal infections and resistance.

致病性酵母白色念珠菌 (Ca) 是免疫系统中真菌感染的主要原因。 包括艾滋病患者在内的受影响人群。通常用抗真菌药物治疗，大多数 通常是广泛用于艾滋病患者的唑类氟康唑。在这些患者中，有一个 产生唑类耐药性的可能性很大。使用来自艾滋病患者的口服耐药菌株， 已经确定了主要的耐药机制，包括 ERG11（编码 麦角甾醇生物合成中的酶和唑类的靶标）以及外排泵的表达增加。 麦角甾醇是真菌质膜中的主要甾醇；其生物合成是唑类的目标 和许多其他抗真菌药 真菌细胞与唑类的相互作用是一个复杂的过程。新陈代谢的具体方面和 环境影响体外药物/细胞相互作用，并有可能在临床上发挥重要作用。这 这项研究的总体目标是了解真菌细胞如何响应唑类药物。这个提议 研究 UPC2 转录因子对甾醇的导入和后续调节，以及 环境因素影响细胞对药物的反应。该提案的具体目标是： 1. 表征氟康唑输入真菌细胞的特征。唑类导入对细胞/药物很重要 相互作用;它可能由被动或主动运输介导；以前没有研究过。 2.分析UPC2的转录调控。一旦进入细胞内，唑类就会抑制 Erg 11 p， 改变甾醇水平，并激活调节甾醇生物合成的 UPC2 转录因子 和吸收。将分析 UPC2 基因的调控，以了解甾醇的变化 代谢（包括摄取和生物合成）与 UPC2 的表达相关。 3. 表征特定环境因素对药物敏感性和细胞的影响 表面。环境因素，包括 pH 值、氧气水平、氮源和外源甾醇， 将使用微生物学分析它们对药物敏感性和细胞表面的影响， 生物化学和基因表达方法。 4. 表征临床分离株的甾醇代谢变化。已知的机制 耐药性不适用于许多耐药菌株。该目标将分析进口、UPC2 监管和 对环境因素的反应，以确定这些分离株中可能的新耐药机制。 了解唑类和真菌细胞之间的相互作用是一个具有临床意义的问题， 改善真菌感染和耐药性的诊断、治疗和预防的潜力。