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: 7827675
• 负责人: Theodore C. White
• 金额: $ 3.07万
• 依托单位: SEATTLE 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: 2009-06-01 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7827675
• 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; 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; Regulation; Research; Research Personnel; Resistance; Resistance development; Resistance to infection; Source; Sterol Biosynthesis Pathway; Sterols; Testing; Transcriptional Regulation; Yeasts; clinically significant; efflux pump; improved; insight; overexpression; patient population; resistance mechanism; resistant strain; 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.

致病酵母菌白色念珠菌是引起免疫缺陷真菌感染的主要原因之一。 受影响的人群包括艾滋病患者。它通常用抗真菌药物治疗，大多数 常用的是在艾滋病患者中广泛使用的唑类氟康唑。在这些患者中，有一种 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， 主要的抗性机制已被确定，包括ERG11(一种编码AND的基因)的变化 麦角甾醇生物合成中的酶和唑类化合物的靶标)和外排泵的表达增加。 麦角甾醇是真菌质膜中的主要甾醇，其生物合成是唑类化合物的靶标。 和许多其他抗真菌药物 真菌细胞与唑类化合物的相互作用是一个复杂的过程。新陈代谢的特定方面和 体外环境影响药物/细胞相互作用，有可能在临床上发挥重要作用。这个 这项研究的总体目标是了解真菌细胞如何对唑类化合物做出反应。这项建议 研究了固醇的进口，随后由Upc2转录因子调节的情况，以及 环境因素对细胞对药物的反应。这项建议的具体目标是： 1.研究氟康唑导入真菌细胞的特性。氮唑进口对细胞/药物很重要 相互作用；它可以通过被动或主动运输来调节；它以前没有被研究过。 2.分析Upc2的转录调控。一旦进入细胞内，氮唑类化合物就会抑制ERG11p， 改变固醇水平，激活调控固醇生物合成的Upc2转录因子 和领悟。将分析Upc2基因的调节，以了解固醇的变化 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 浮出水面。环境因素，包括pH、氧气水平、氮源和外源甾醇， 将分析它们对药物敏感性和细胞表面的影响，使用微生物学， 生物化学和基因表达方法。 4.确定临床分离株的甾醇代谢变化特征。已知的致病机制 耐药性并不适用于许多耐药菌株。这一目标将检测导入、Upc2调控和 对环境因素的反应，以确定这些分离物中可能的新的抗性机制。 了解唑类化合物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。