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A novel metal-starvation candidacidal mechanism for Histatin 5

组蛋白 5 的新型金属饥饿候选机制

基本信息

批准号：
10058265
负责人：
Hannah Lynn Norris
金额：
$ 3.08万
依托单位：
STATE UNIVERSITY OF NEW YORK AT BUFFALO
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-12-01 至 2021-11-14
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10058265
关键词：
Affinity Aftercare Alternative Therapies Antifungal Agents Binding Biotin Candida Candida albicans Candidiasis Cations Cell Cycle Cell Cycle Arrest Cell Maintenance Cell physiology Cells Cellular Assay Chelating Agents Clinical Clinical Research Complex Copper Data Drug Metabolic Detoxication Esophagus Feedback Flow Cytometry Fungal Drug Resistance Future G1 Arrest Glycerol Growth Health Homeostasis Human Immunocompromised Host Impairment In Vitro Inductively Coupled Plasma Mass Spectrometry Industrial fungicide Infection Ions Label Major salivary gland structure Measures Mediating Messenger RNA Metal Binding Site Metals Mitogen-Activated Protein Kinases Molecular Mutation Nutritional Immunity Oropharyngeal Osmolar Concentration Oxidases Oxidative Stress Pathogenesis Pathway interactions Peptides Phosphorylation Population Predisposition Process Production Property Proteins Reactive Oxygen Species Regulation Regulon Research Resistance Saliva Salivary Signal Pathway Signal Transduction Starvation Stress Superoxide Dismutase Testing Transcript Work Zinc Zinc deficiency alternative treatment antimicrobial peptide biological adaptation to stress cell type chelation clinical application cyclin G1 design differential expression histatin 5 inhibitor/antagonist insight metal chelator metal complex mutant novel opportunistic pathogen oral commensal pathogen pathogenic fungus prevent recurrent infection response superoxide dismutase 1 tool transcriptome sequencing uptake

项目摘要

Project Summary: Oropharyngeal and esophageal candidiasis are mainly caused by the opportunistic pathogen Candida albicans and continue to be a health issue in immunocompromised populations. Recurrent infections of C. albicans are often resistant to multiple major antifungal drug types. In these cases there are few alternative therapies since clinically available antifungals target a limited number of fungal pathways. Salivary Histatin 5 (Hst 5) is secreted by human major salivary glands and has high in vitro fungicidal activity against C. albicans and other Candida species. Hst 5 has a mechanism of action that is distinct from antifungal drugs currently in use, making it an attractive alternative treatment; however the ultimate mechanism of killing is unclear. Hst 5 treatment induces several effects on C. albicans cells, including reactive oxygen species (ROS) accumulation, activation of the high osmolarity glycerol (HOG1) pathway and cell cycle arrest in G1, however its underlying mechanism of action is still mostly unknown. Importantly, Hst 5 is able to bind zinc (Zn2+) and copper (Cu2+) ions with high affinity and binding of these metals has been shown to impact killing activity for unknown reasons. Entry of Hst 5 into fungal cells is required for its high killing activity, and free metal binding sites appear to be necessary for uptake of the peptide; therefore the central hypothesis of this project is that Hst 5 enters fungal cells to deplete intracellular Zn2+ and Cu2+, which is the mechanism by which Hst 5 induces oxidative stress, changes in HOG1 signaling, and G1 cell cycle arrest in C. albicans. As a tool to probe the metal-dependent effects of Hst 5, a mutant Hst 5 peptide that is designed to be deficient in metal binding will be used. In Aim 1, the ability of Hst 5 to deplete intracellular Zn2+ and Cu2+ will be verified, and the expression and activity of ROS-detoxifying superoxide dismutase proteins during Hst 5 mediated metal depletion will be characterized. In Aim 2 the ability of Zn2+ to regulate HOG1 pathway signaling and cell cycle arrest will be tested, and it will be confirmed that Hst 5 treatment dysregulates these processes through intracellular Zn2+ depletion. Completion of this project will be a valuable step forward in research into the Hst 5 mechanism of action, and provide new characterization of C. albicans stress responses.

项目总结：口咽和食道念珠菌病主要由条件致病菌白色念珠菌引起。在免疫功能低下的人群中，这仍然是一个健康问题。白念珠菌的反复感染有通常对多种主要的抗真菌药物产生抗药性。在这些情况下，几乎没有替代疗法，因为临床上可用的抗真菌药物针对的是有限数量的真菌途径。唾液组织蛋白5(HST 5)是由人的主要唾液腺分泌，对白色念珠菌等具有较高的体外杀菌活性假丝酵母菌。HST 5具有不同于目前使用的抗真菌药物的作用机制，这使其成为一种有吸引力的替代治疗方法；然而，最终的致死机制尚不清楚。HST 5 治疗对白色念珠菌细胞有几种影响，包括活性氧(ROS)的积累，高渗透压甘油(HOG1)途径的激活和G1期细胞周期的停滞其作用机制大多尚不清楚。重要的是，HST-5能够结合锌和铜与这些金属具有高亲和力和结合力的离子已被证明影响杀戮活性，原因不明理由。HST-5进入真菌细胞是其高杀伤活性和游离金属结合部位所必需的似乎是摄取多肽所必需的；因此，该项目的中心假设是HST 5进入真菌细胞，耗尽细胞内的锌和铜，这是HST 5的机制在白色念珠菌中诱导氧化应激，HOG1信号的改变，以及G1细胞周期停滞。作为一种工具为了探索HST 5的金属依赖效应，HST 5是一种被设计为缺乏金属的突变型HST 5肽将使用装订。在目标1中，将验证HST 5耗尽细胞内锌和铜的能力，以及 HST-5介导的金属过程中ROS解毒超氧化物歧化酶蛋白的表达和活性将以耗尽为特征。目的2锌离子调节HOG1信号通路和细胞周期的能力将对抑制进行测试，并将确认HST-5治疗通过胞内锌离子耗竭。该项目的完成将是HST 5研究向前迈出的宝贵一步作用机制，并提供了白色念珠菌应激反应的新特征。