基于脂代谢探讨蚊虫自噬调控wolbachia密度的作用机制

The ability of wolbachia-medicated inhibition of viruses depends on its density. Autophagy is an important and well-conserved mechanism against virus and bacteriae in eukaryotic cells. And it has been found to be a key factor to modulate wolbachia density.But the mechanism is unclear. Previous work by applicant showed multiple lipid metabolic genes were up-regulated in mosquito salivary gland by wolbachia. Based on the conclusions from mammals, autophagy can modulate lipid metabolism and lipid droplet can modulate autophagosome biogenesis, we proposed the scientific hypothesis that mosquito autophagy might modulate lipid metabolism to influence wolbachia density. So this project will be performed to study the relationship between autophagy induced by wolbachia and its density in vitro and invivo, to clarify the change of lipid metabolism induced by wolbachia from the omics, and to investigate the relationship between lipid metabolism and wolbachia density when autophagy is activated or inhibited.Based on these results, it could be illuminated the role of lipid metabolism on mosquito autophagy modulated wolbachia density; it also could provide theoretical basis for wolbachia as a biocontrol agent to control arbodiseases efficently and sustainably.

内生菌wolbachia的密度决定其诱导的抗病原能力。自噬作为真核生物抗胞内病毒和细菌的一个重要的防御机制，有研究发现它是调控wolbachia密度的关键因素，但其具体的作用机制未明。申请者前期工作发现，wolbachia感染可诱导蚊虫唾液腺内多个脂代谢相关基因上调。基于哺乳动物的研究发现，自噬可调控胞内脂代谢，而胞内脂滴可促进自噬的发生，据此我们提出假说，wolbachia诱导的自噬可能通过干扰细胞内的脂代谢而影响其密度。为此本课题拟从蚊虫细胞、组织水平研究wolbachia诱导的自噬与其密度关系，从组学角度明确wolbachia对蚊虫脂类代谢的影响，进而探讨在自噬被激活或抑制条件下，胞内脂代谢与wolbachia密度的关系，初步阐明脂代谢在蚊虫自噬调控wolbachia密度中的作用机制，为以wolbachia为生物防制剂高效、可持续控制蚊媒病提供理论依据。

内生菌wolbachia的密度决定其诱导的抗病原能力。为了探讨自噬、脂代谢对wolbachia密度的影响，我们以waco株埃及伊蚊（无wolbachia感染）/WB株埃及伊蚊（Walb株wolbachia感染）,Aa23T/Aa23细胞为研究对象，开展了如下工作：1. Walb株wolbachia在埃及伊蚊雌蚊体内，随着日龄的增加而密度升高，不同组织间以卵巢的密度最高，中肠最低。这种密度的变化与蚊虫的自噬基础水平没有相关性；2.细胞水平、蚊虫水平实验证明Wolbachia感染可以调控宿主体内脂类物质变化，主要是以甘油三酯的增加为主；但这种变化与wolbachia密度没有显著关系；3. 相较于waco株，WB株蚊虫通过抑制自噬来确保体内一定密度的wolbachia；4. 吸血可以激活自噬，随着吸血时间延长，wolbachia密度在蚊虫卵巢组织显著下降，36小时达到最低，72小时基本恢复；在脂肪体和剩余组织随着吸血时间的延长，wolbachia密度增加；4. 采用自噬激活剂RAPA和自噬抑制剂3MA激活或抑制自噬后，细胞水平、蚊虫水平均发现TG下降或增加；wolbachia密度在自噬激活时下降；在自噬抑制时，细胞水平下降，蚊虫水平上升。5.不同饮食可以改变蚊虫体内wolbachia的密度，实验室蚊虫饲喂建议用白糖饲喂，以保持wolbachia密度。基于以上结果，得到如下结论：1.wolbachia感染促进蚊虫宿主体内甘油三酯的贮存，但与wolbachia密度无关。2.自噬可以调控wolbachia的密度，但与蚊虫宿主的脂类变化没有直接相关性。