Regulation of Sexual Differentiation in Malaria Parasites

疟疾寄生虫性别分化的调节

• 批准号: 10161718
• 负责人: Bjorn Felix Caesar Kafsack
• 金额: $ 55.69万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-12 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10161718
• 关键词: Automobile Driving; Biochemical; Blood; Cell Cycle; Cells; Cessation of life; Chromatin; Chromatin Structure; Communicable Diseases; Culicidae; DNA-Binding Proteins; Data; Development; Disease; Enzyme Inhibitor Drugs; Enzymes; Eukaryota; Female; Gene Expression; Gene Expression Profiling; Gene Expression Regulation; Gene Mutation; Gene Silencing; Genes; Genetic; Genetic Transcription; Genomics; Goals; Growth; Health; Heterochromatin; Human; Impairment; In Vitro; Incidence; Individual; Intervention; Lead; Life Cycle Stages; Liver; Maintenance; Malaria; Malaria prevention; Mediating; Morbidity - disease rate; Morphology; Mosquito-borne infectious disease; Parasites; Pharmaceutical Preparations; Phase; Play; Predisposition; Process; Prophylactic treatment; Publishing; Regulation; Reporting; Research Personnel; Role; Sex Differentiation; Sexual Development; Sporozoites; Testing; Time; Up-Regulation; Vector-transmitted infectious disease; asexual; base; cancer therapy; cell type; chromatin remodeling; design; enhancer-binding protein AP-2; experimental study; follow-up; gene function; genome-wide; histone demethylase; inhibitor/antagonist; knock-down; malaria transmission; male; mortality; novel; novel strategies; programs; protein function; protein protein interaction; targeted treatment; transcriptomics; transmission process; vector mosquito

! PROJECT SUMMARY/ABSTRACT Malaria is the mosquito-borne disease responsible for the greatest morbidity and mortality world-wide. After significant reductions over the past two decades, malaria incidence and mortality have plateaued over the last five years highlighting the need for additional interventions. Malaria transmission requires parasites to differentiate from the replicating asexual blood stages to non-replicating male and female gametocytes necessary to infect mosquitos. The early stages of gametocyte development are a key period during which parasites not only need to initiate the gametocyte-specific transcriptional program, but must also block expression of genes that lead to cell-cycle entry associated with asexual replication. Our long-term goal is to block transmission and replication of malaria parasites by interfering with the regulatory mechanisms that govern this essential point of control in the parasite lifecycle. Recent studies reported specific up-regulation of chromatin-modifying enzymes in sexually committed parasites, suggesting that chromatin re-organization plays a crucial role during the asexual to gametocyte transition. While technical barriers have thwarted studying chromatin organization and gene expression in these critical early stages of gametocyte development, a recently published study observed specific expansion of subtelomeric heterochromatin domains in more mature gametocytes. This proposal aims to test the hypothesis that restructuring of the parasite chromatin landscape in sexually committed parasites and early gametocytes is critical for the developmental switch from asexual replication to the formation of transmissible forms. New approaches, including single-cell transcriptomics and cell-type specific chromatin analysis, now allow researchers to define gene expression and chromatin organization during early gametocyte development for the first time (Aim 1) and study the function of genes critical for regulation of chromatin specifically during gametocyte development. Experiments in Aim 2 will define the critical role of putative histone demethylases in gametocyte development. While these enzymes appear individually dispensable for asexual growth in vitro, they are notably upregulated in gametocytes, and early gametocytes are highly susceptible to inhibitors of these enzymes, with susceptibility peaking in gametorings and Stage I gametocytes. Lastly, Aim 3 focuses on defining the role of a newly identified DNA- binding protein in heterochromatin mediated gene-silencing during gametocyte development. Preliminary experiments show that loss of expression results in aberrant gametocyte development, upregulation of heterochromatin-silenced genes, and alterations in chromatin organization. The proposed experiments will offer a first window into the critical early stages of gametocyte development and provide new targets for transmission blocking strategies. !

! 项目总结/摘要 疟疾是蚊子传播的疾病，在世界范围内造成最高的发病率和死亡率。后 尽管疟疾发病率和死亡率在过去20年中显著下降， 五年来，强调需要更多的干预措施。疟疾的传播需要寄生虫 从复制的无性血液阶段分化为非复制的雄性和雌性配子体 是感染蚊子所必需的。配子体发育的早期阶段是一个关键时期， 寄生虫不仅需要启动配子体特异性转录程序，而且还必须阻断 导致与无性复制相关的细胞周期进入的基因表达。我们的长期目标是 通过干扰调节机制阻止疟原虫的传播和复制， 控制着寄生虫生命周期中的关键控制点。最近的研究报道了特异性上调 染色质修饰酶在性定向寄生虫，这表明染色质重组发挥作用， 在无性生殖向配子体转化的过程中起着至关重要的作用。虽然技术壁垒阻碍了研究 在配子体发育的这些关键早期阶段， 最近发表的一项研究观察到， 成熟配子体这项提议旨在验证寄生虫染色质重组的假设， 性定向寄生虫和早期配子母细胞中的景观对于从 无性繁殖到形成可传播的形式。新方法，包括单细胞 转录组学和细胞类型特异性染色质分析，现在允许研究人员定义基因表达， 第一次（Aim 1）研究早期配子体发育过程中的染色质组织，并研究 在配子母细胞发育过程中对染色质的调节起关键作用的基因。目标2中的实验 将确定假定的组蛋白去甲基化酶在配子体发育中的关键作用。虽然这些酶 在体外单独表现为无性生长，它们在配子体中显著上调， 早期配子母细胞对这些酶的抑制剂高度敏感， 配子体和阶段I配子母细胞。最后，目标3侧重于定义新发现的DNA的作用- 异染色质结合蛋白介导的配子体发育过程中的基因沉默。初步 实验表明，表达缺失导致异常配子体发育， 异染色质沉默基因和染色质组织的改变。拟议的实验将 为配子母细胞发育的关键早期阶段提供了第一个窗口，并为 传输阻塞策略。 !