Research. Global Analysis of Posttranscriptional Gene Expression in Response to Sodium Arsenite.

Autor: Lian-Qun Qiu1, Abey, Sarah1, Harris, Shawn2, Shah, Ruchir2, Gerrish, Kevin E.3, Blackshear, Perry J.1,4,5 Black009@niehs.nih.gov
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Zdroj: Environmental Health Perspectives. Apr2015, Vol. 123 Issue 4, p324-330. 7p. 2 Charts, 3 Graphs.
Abstrakt: Background: Inorganic arsenic species are potent environmental toxins and causes of numerous health problems. Most studies have assumed that arsenic-induced changes in mRNA levels result from effects on gene transcription. Objectives: We evaluated the prevalence of changes in mRNA stability in response to sodium arsenite in human fibroblasts. Methods: We used microarray analyses to determine changes in steady-state mRNA levels and mRNA decay rates following 24-hr exposure to noncytotoxic concentrations of sodium arsenite, and we confirmed some of these changes using real-time reverse-transcription polymerase chain reaction (RT-PCR). Results: In arsenite-exposed cells, 186 probe set-identified transcripts were significantly increased and 167 were significantly decreased. When decay rates were analyzed after actinomycin D treatment, only 4,992 (9.1%) of probe set-identified transcripts decayed by > 25% after 4 hr. Of these, 70 were among the 353 whose steady-state levels were altered by arsenite, and of these, only 4 exhibited significantly different decay rates between arsenite and control treatment. Real-time RT-PCR confirmed a major, significant arsenite-induced stabilization of the mRNA encoding δ aminolevulinate synthase 1 (ALAS1), the rate-limiting enzyme in heme biosynthesis. This change presumably accounted for at least part of the 2.7-fold increase in steady-state ALAS1 mRNA levels seen after arsenite treatment. This could reflect decreases in cellular heme caused by the massive induction by arsenite of heme oxygenase mRNA (HMOX1; 68‑fold increase), the rate-limiting enzyme in heme catabolism. Conclusions: We conclude that arsenite modification of mRNA stability is relatively uncommon, but in some instances can result in significant changes in gene expression. Citation: Qiu LQ, Abey S, Harris S, Shah R, Gerrish KE, Blackshear PJ. 2015. Global analysis of posttranscriptional gene expression in response to sodium arsenite. Environ Health Perspect 123:324-330; http://dx.doi.org/10.1289/ehp.1408626 [ABSTRACT FROM AUTHOR]
Databáze: GreenFILE
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