Pex8调控线粒体凋亡通路在米替福新抗耐药念珠菌中的机制研究

有限的抗真菌药物使得侵袭性真菌感染的治疗尤为棘手。申请人前期发现“老药”米替福新具有抗耐药念珠菌作用，但其抗真菌机制尚不明确。申请人前期基于白念珠菌研究发现，米替福新能够显著降低线粒体膜电位，并诱导白念珠菌凋亡；敲除PEX8或线粒体凋亡通路关键基因AIF1后，菌株对米替福新敏感性降低，而过表达基因PEX8或AIF1的菌株则对米替福新敏感性增加。此外，敲除PEX8基因后，米替福新无法诱导Aif1高表达。这提示Pex8激活Aif1介导的线粒体凋亡通路可能是米替福新诱导念珠菌凋亡的潜在机制。本项目拟通过基因操作技术、分子生物学技术和多组学分析等展开研究：1）揭示Pex8在米替福新诱导白念珠菌凋亡中的作用机制；2）研究Pex8对Aif1亚细胞定位及其蛋白表达的作用机制，并阐明Pex8对线粒体凋亡通路的调控机制。本课题研究对促进米替福新抗真菌作用的临床转化和发现新型抗真菌药物靶点具有重要意义。

Limited antifungal drugs make the treatment of invasive candidiasis particularly difficult. The applicant previously found that the conventional drug miltefosine has fungicidal activity for resistant Candida species, but its antifungal mechanisms are not clear. Based on Candida albicans, we found that miltefosine reduced the mitochondrial membrane potential of Candida albicans and induced apoptosis; knocking out of PEX8 or AIF1 made the strain more sensitive to miltefosine, while overexpressing PEX8 or AIF1 in the strain increased its resistance to miltefosine. In addition, the expression level of Aif1 was significantly up-regulated with miltefosine, but it could not be up-regulated without Pex8. These results suggest that the activation of Aif1 medicated mitochondrial apoptosis pathway by Pex8 may be a potential mechanism for miltefosine to induce apoptosis of Candida species. This project intends to carry out the following studies through gene manipulation technology, molecular biology technology and multi-omics analysis: 1) to reveal the regulatory role of Pex8 in Candida albicans apoptosis induced by miltefosine; 2) to study the effect of Pex8 on the subcellular localization and protein expression of Aif1, and clarify the regulation mechanism of Pex8 on the mitochondrial apoptosis pathway. This study is of great significance to promote the clinical transformation of the antifungal effect of miltefosine and to find new antifungal drug targets.