微囊藻毒素的母代转移途径及其诱发子代神经毒性的机制研究

In recent decades, public health concerns about toxic cyanobacteria have increased due to the frequent occurrence of cyanotoxins in both drinking and recreational waters. Among cyanotoxins, microcystins (MCs) are the most common all over the world, with molecular weights ranging between 900 and 1000 Da. So far, more than 80 different structural analogues of MCs have been identified, with microcystin-leucine-arginine (MCLR) being the most common variant and toxic. Previous studies together with our findings have shown that MCLR can be transferred to offspring from their adults and induced deficits in learning and memory, eventually leading to notable neurotoxicity, but the exact mechanism is little known. During the present research, many technologies, such as behavioral test, morphological observation, in vivo electrophysiological recording, HPLC-ESI-MS, real-time reverse transcriptional polymerase chain reaction (real-time PCR), and Western blot were employed to explore the pathway in which MCLR was transferred from the adults to the offspring and accumulating rules of MCLR in the tissues of offspring. Especially, we would focus on the role of CaN-triggered mitochondria apoptosis pathway in MCLR-induced deficits in learning and memory. Meanwhile, the proteomics and metabolomics will be employed to search the target protein and metabolic programmed alteration, the results of which could be used to identify the potential biomarkers for MCLR induced neurotoxicity in the offspring. Our results will elucidate the molecular mechanisms in the neurotoxicity induced by maternal transfer in the offspring from a new perspective. Our findings would also provide the new ideas and theoretical references for preventing the hazards of MCs.

水体富营养化引起蓝藻水华大规模暴发，随藻细胞破裂释放出来的微囊藻毒素(microcystins，MCs)对动物和人的机体健康造成了极大危害。MCs有80余种变体，其中MCLR毒性最强。申请人的最新研究成果显示，MCLR可通过母体转移至子代脑组织，造成强烈的神经毒性效应，但其转移途径及致毒机理还缺乏深入研究。本课题拟利用行为学、形态学、液质联用仪、激光共聚焦显微镜、Western blot、实时定量PCR等多种技术揭示MCLR的母代转移途径、阐述其在子代组织中的蓄积规律、重点关注钙调神经磷酸酶（CaN）介导的线粒体凋亡途径在MCLR诱发的子代认知记忆损伤中的作用，并从蛋白组学水平挖掘致毒靶蛋白，从代谢组学角度筛选诱发子代神经毒性的生物标志物，建立预警诊断方法。本项目是在已有基础上进行更加深入的探索，可拓展人们对MCLR的母代转移效应及其诱发子代神经毒性的认知，为MCLR的防治提供理论依据。

蓝藻水华在世界范围内的频繁暴发引起了国内外的广泛关注，其次生代谢产物蓝藻毒素对生态环境和人类健康造成严重威胁。微囊藻毒素（MCs）是自然界中最为常见、危害最大的一类蓝藻毒素，而微囊藻毒素-LR（MCLR）是MCs中毒性最强，分布最为广泛的一种。针对MCLR对自然水体的污染可能会对生态环境及人类健康造成的潜在危害，本项目我们以斑马鱼和小鼠为实验动物，首先利用MCLR急性暴露斑马鱼胚胎，研究MCLR诱发斑马鱼胚胎神经毒性分子机制；其次利用环境浓度MCLR慢性暴露成年斑马鱼和孕鼠，一方面研究了MCLR在母体以及子代（斑马鱼胚胎和胎鼠）的蓄积，阐述了MCLR的母代转移规律，另一方面揭示了MCLR的母代传递抑制子代生长发育和诱发子代神经毒性的分子机制。本研究为全面、系统评估MCLR诱发的神经毒性效应、母代传递效应和子代发育毒性效应提供了重要的实验依据。