Trophic transfer of carbon-14 from algae to zebrafish leads to its blending in biomolecules and the dysregulation of metabolism via isotope effect  

作　　者：Shipeng Dong Renquan Deng Hang Zeng Pengfei Xue Sijie Lin Dongmei Zhou Liang Mao 

机构地区：[1]State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,Chemistry and Biomedicine Innovation Center,Nanjing University,Nanjing 210023,China [2]College of Environmental Science&Engineering,State Key Laboratory of Pollution Control and Resource Reuse,Tongji University,Shanghai 200092,China

出　　处：《National Science Review》2025年第1期149-160,共12页国家科学评论(英文版)

基　　金：supported by the National Natural Science Foundation of China(22125602,U2067215,22341601,22076078 and 22376095).

摘　　要：Carbon-14(C-14)has been a major contributor to the human radioactive exposure dose,as it is released into the environment from the nuclear industry in larger quantities compared to other radionuclides.This most abundant nuclide enters the biosphere as organically bound C-14(OBC-14),posing a potential threat to public health.Yet,it remains unknown how this relatively low radiotoxic nuclide induces health risks via chemical effects,such as isotope effect.By establishing a trophic transfer model involving algae(Scenedesmus obliquus),daphnia(Daphnia magna)and zebrafish(Danio rerio),we demonstrate that rapid incorporation and transformation of inorganic C-14 by algae into OBC-14 facilitates the blending of C-14 into the biomolecules of zebrafish.We find that internalized C-14 is persistently retained in the brain of zebrafish,affecting DNA methylation and causing alterations in neuropathology.Global isotope tracing metabolomics with C-14 exposure further reveals the involvement of C-14 in various critical metabolic pathways,including one-carbon metabolism and nucleotide metabolism.We thus characterize the kinetic isotope effects for^(12)C/^(14)C in the key reactions of these metabolic pathways through kinetic experiments and density functional theory computations,showing that the isotopic substitution of carbon in biochemicals regulates metabolism by disrupting reaction ratios via isotope effects.Our results suggest that inorganic C-14 discharged by the nuclear industry can be biotransformed into OBC-14 to impact metabolism via isotope effects,providing new insights into understanding the health risk of C-14,which is traditionally considered as a low radiotoxic nuclide.

关 键 词：organically bound carbon-14 trophic transfer isotope effects metabolism dysregulation isotopic substitution 

分 类 号：O57[理学—粒子物理与原子核物理]