Targeting the regulatory mechanism of hyphae to lateral yeast growth as a novel therapeutic approach against candidiasis

摘要 一种单一的白色念珠菌导致了人类一半的侵袭性真菌感染。结果表明，C. 白念珠菌在酵母和Hyphe之间可逆切换是一种主要的毒力特征，有助于它传播到 血液(酵母菌)和侵入的目标器官(细丝)。酵母菌对菌丝的形态发生 经过广泛的研究，其规则也得到了很好的理解。相反，人们对反面知之甚少。 工艺：菌丝至酵母菌生长。白色念珠菌的菌丝从它们的侧隔区产生酵母细胞， 被称为“横向酵母菌”。这些侧生酵母菌总是在活跃的感染部位发现有菌丝， 是重新进入血流并建立远端感染灶的主要细胞。事实上，横向酵母菌 从被生物膜污染的导管的菌丝层释放的细胞可以直接进入 血液流动。我们确定了菌丝到侧向酵母生长的第一个调节剂PES1，并表明 阻断这一过程(通过在体内耗尽PES1)可以根除播散性念珠菌病和生物被膜。 伴发的念珠菌血症。关于PES1的监管方面，我们一无所知。我们的初步研究表明 Ras-PKA对Pes1的磷酸化抑制酵母的侧向生长，而Ras-PKA对其去磷酸化则抑制酵母的侧向生长。 连接的磷酸酶Yvh1激活菌丝的侧向酵母出现，并诱导生物膜扩散。vbl.使用 PES1作为鉴定酵母侧向生长的小分子抑制剂的靶标，确定了阿列西定 二盐酸盐直接抑制Pes1和Yvh1并保护小鼠免受生物被膜的影响 播散性念珠菌病。在这里，使用蛋白质生物化学分析，我们建议描绘信号如何 通过RAS-PKA调节Pes1的表达。我们将确定其他与Pes1相互作用的同源调控因子来控制 酵母的横向生长，并利用这些信息发现新的化合物，可以中断菌丝到横向 酵母菌生长和播散性念珠菌病。最终，留置药物的患者会有更好的结果 设备是此应用程序的目标。

Abstract A single species Candida albicans, causes half of all invasive fungal infections in humans. The ability of C. albicans to switch reversibly between yeast and hyphe is a major virulence trait that helps it disseminate into the bloodstream (yeast) and invade target organs (filaments). Yeast to hyphae morphogenesis has been extensively studied and its regulation well understood. To the contrary, little is known about the reverse process: hyphae to yeast growth. C. albicans hyphae produce yeast cells from their lateral septal regions, coined as “lateral yeasts”. These lateral yeasts are always found with hyphae at the site of active infection, are the major cells that re- enter the bloodstream and establish distal foci of infection. In fact, lateral yeast cells released from the hyphal layers of biofilm-contaminated catheters have direct access into the bloodstream. We identified the first regulator of hyphae-to-lateral yeast growth, PES1 and have shown that blocking the process (by depleting PES1 in vivo) can abrogate disseminated candidiasis as well as biofilm- associated candidemia. Nothing is known on the regulatory aspects pf PES1. Our preliminary studies show that phosphorylation of Pes1 by Ras-PKA inhibits lateral yeast growth while its dephosphorylation by a Ras- linked phosphatase Yvh1 activates lateral yeast emergence from hyphae and induces biofilm dispersal. Using PES1 as a target for identifying small molecule inhibitors of lateral yeast growth, identified alexidine dihydrochloride that directly inhibited both Pes1 and Yvh1 and protected mice from biofilm-associated disseminated candidiasis. Here, using protein biochemistry assays, we propose to delineate how signaling through Ras-PKA regulates Pes1. We will identify other cognate regulators that interact with Pes1 to control lateral yeast growth, and use this information to discover novel compounds that can interrupt hyphae to lateral yeast growth and disseminated candidiasis. Ultimately, better outcomes for patients with indwelling medical devices is the goal of this application.