کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4470270 1314417 2010 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Direct speciation analysis of arsenic in sub-cellular compartments using micro-X-ray absorption spectroscopy
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست بهداشت، سم شناسی و جهش زایی
پیش نمایش صفحه اول مقاله
Direct speciation analysis of arsenic in sub-cellular compartments using micro-X-ray absorption spectroscopy
چکیده انگلیسی

Identification of arsenic chemical species at a sub-cellular level is a key to understanding the mechanisms involved in arsenic toxicology and antitumor pharmacology. When performed with a microbeam, X-ray absorption near-edge structure (μ-XANES) enables the direct speciation analysis of arsenic in sub-cellular compartments avoiding cell fractionation and other preparation steps that might modify the chemical species. This methodology couples tracking of cellular organelles in a single cell by confocal or epifluorescence microscopy with local analysis of chemical species by μ-XANES. Here we report the results obtained with a μ-XANES experimental setup based on Kirkpatrick–Baez X-ray focusing optics that maintains high flux of incoming radiation (>1011 ph/s) at micrometric spatial resolution (1.5×4.0 μm2). This original experimental setup enabled the direct speciation analysis of arsenic in sub-cellular organelles with a 10−15 g detection limit. μ-XANES shows that inorganic arsenite, As(OH)3, is the main form of arsenic in the cytosol, nucleus, and mitochondrial network of cultured cancer cells exposed to As2O3. On the other hand, a predominance of As(III) species is observed in HepG2 cells exposed to As(OH)3 with, in some cases, oxidation to a pentavalent form in nuclear structures of HepG2 cells. The observation of intra-nuclear mixed redox states suggests an inter-individual variability in a cell population that can only be evidenced with direct sub-cellular speciation analysis.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Environmental Research - Volume 110, Issue 5, July 2010, Pages 413–416
نویسندگان
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