Lead homeostasis in extremophile earthworms: time and space resolved changes in metal speciation

极端微生物蚯蚓的铅稳态：时间和空间解决了金属形态的变化

• 批准号: 2325447
• 金额: --
• 依托单位: King's College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2325447
• 关键词: Lead; homeostasis; extremophile; earthworms; time

Heavy metal pollution is a growing issue due to its persistency and routes of spread. Non-essential heavy metals such as lead exhibit deleterious effects through mimicry of essential elements e.g. calcium. Thus, lead bioaccumulation is known to disrupt the function of the central nervous system and has been associated with an early onset of neurodegenerative diseases. Earthworms populating heavy metal polluted landscapes have evolved distinct homeostatic mechanisms for metal detoxification. Omics-based approaches may: provide clues for treatment of metal toxicity; improved soil toxicity testing measures; advance soil vermiremediation research; determine mechanisms of earthworm quantum dot biosynthesis. Laser Ablation Inductively Coupled Plasma Mass Spectrometry imaging was used to compare lead bioaccumulation patterns in the brain and the gut of lead-resistant and control earthworms exposed to equal doses of lead in soil. Metallomic maps qualitatively revealed several biological adaptations including: accumulation of phenomenal amounts of lead in the gut (~30X greater than the control); low lead bioaccumulation in the brain (~10X lower than the control); precise lead sequestration into designated storage/detoxifying tissues (chloragogen tissues in gut, neuronal cell bodies in brain). Future studies will employ imaging mass cytometry, single cell transcriptomics, and synchrotron radiation to reveal molecular mechanisms of lead detoxification.

由于重金属污染的持久性和传播途径，其污染问题日益严重。非必需重金属（如铅）通过模仿必需元素（如钙）表现出有害影响。因此，已知铅的生物蓄积会破坏中枢神经系统的功能，并与神经退行性疾病的早期发病有关。蚯蚓在重金属污染景观中已经进化出了独特的重金属解毒稳态机制。基于组学的方法可能为金属毒性的治疗提供线索；改进土壤毒性检测措施；土壤蚓类修复研究进展确定蚯蚓量子点生物合成的机制。采用激光烧蚀电感耦合等离子体质谱成像技术比较了暴露于土壤中等剂量铅的抗铅蚯蚓和对照蚯蚓的大脑和肠道中铅的生物积累模式。金属图谱定性地揭示了几种生物适应性，包括：肠道中铅的积累量惊人（比对照组多30倍）；脑内铅生物蓄积量低（比对照组低~10倍）；精确地将铅隔离到指定的储存/解毒组织（肠道中的氯原组织，大脑中的神经元细胞体）。未来的研究将采用成像细胞术、单细胞转录组学和同步辐射来揭示铅解毒的分子机制。