High-resolution imaging of Hg/Se aggregates in the brain of small Indian mongoose, a wild terrestrial species: insights into intracellular Hg detoxification

Journal Article · 15 November 2023 · Environmental Chemistry Letters

DOI: https://doi.org/10.1007/s10311-023-01666-3 · OSTI ID:2222382

Devabathini, Pavani ^[1]; Fischer, Darrell L. ^[1]; Chen, Si ^[2]; Pattammattel, Ajith ^[3]; Bury, Gabriel ^[1]; Antipova, Olga ^[2]; Huang, Xiaojing ^[3]; Chu, Yong S. ^[3]; Horai, Sawako ^[4]; Pushkar, Yulia  ^[1]

---

1. Purdue University, West Lafayette, IN (United States)
2. Argonne National Laboratory (ANL), Argonne, IL (United States)
3. Brookhaven National Laboratory (BNL), Upton, NY (United States). National Synchrotron Light Source (NSLS)
4. Tottori University, Tottori (Japan)

Human activities result in the emission of 2000 metric tons of mercury compounds annually. Mercury (Hg) biomagnification has been characterized in marine mammals and predatory fish; however, little is known about mercury accumulation in brains of wild terrestrial species. Elevated Hg content, of 1.27 μg/g wet wt.—found in the brain of wild small Indian mongoose, prompted us to use synchrotron X-ray fluorescence imaging for simultaneous, quantitative mapping of biologically relevant and neurotoxic elements with high spatial resolution. X-ray fluorescence combined with immunohistochemistry revealed ~0.5–1.9 micron Hg-rich aggregates in cells of the choroid plexus and astrocytes of the subventricular wall in the mongoose brain. Hg content within aggregates correlated with selenium. Hg aggregates did not co-localize with lysosomes. The low Hg density inside aggregates indicated diffuse Hg binding to a Se-containing biomolecule, rather than much denser HgSe nanoparticles proposed to form in other species. Our data show the susceptibility of the small Indian mongoose population to Hg pollution and highlight the vulnerability of the brain as an organ targeted by mercury. Data also provide evidence on the adaptation in the form of a Se-based detoxification mechanism sequestering Hg into intracellular aggregates.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); Purdue Research Foundation; Showalter Foundation; Ministry of Education, Culture, Sports, Science, and Technology (MEXT)
• Grant/Contract Number: SC0012704; AC02-06CH11357
• OSTI ID: 2222382
• Report Number(s): BNL--225025-2023-JAAM
• Journal Information: Environmental Chemistry Letters, Journal Name: Environmental Chemistry Letters Vol. 22; ISSN 1610-3653
• Publisher: SpringerCopyright Statement
• Country of Publication: United States
• Language: English