Prenatal exposures and exposomics of asthma

This review examines the causal investigation of preclinical development of childhood asthma using exposomic tools. We examine the current state of knowledge regarding early-life exposure to non-biogenic indoor air pollution and the developmental modulation of the immune system. We examine how metabolomics technologies could aid not only in the biomarker identification of a particular asthma phenotype, but also the mechanisms underlying the immunopathologic process. Within such a framework, we propose alternate components of exposomic investigation of asthma in which, the exposome represents a reiterative investigative process of targeted biomarker identification, validation through computational systems biology and physical sampling of environmental medi

Impact of SO2 on Arabidopsis thaliana transcriptome in wildtype and sulfite oxidase knockout plants analyzed by RNA deep sequencing

Hamisch D, Randewig D, Schliesky S, et al. Impact of SO2 on Arabidopsis thaliana transcriptome in wildtype and sulfite oxidase knockout plants analyzed by RNA deep sequencing. New Phytologist. 2012;196(4):1074-1085.High concentrations of sulfur dioxide (SO2) as an air pollutant, and its derivative sulfite, cause abiotic stress that can lead to cell death. It is currently unknown to what extent plant fumigation triggers specific transcriptional responses. To address this question, and to test the hypothesis that sulfite oxidase (SO) is acting in SO2 detoxification, we compared Arabidopsis wildtype (WT) and SO knockout lines (SO-KO) facing the impact of 600 nl l (1) SO2, using RNAseq to quantify absolute transcript abundances. These transcriptome data were correlated to sulfur metabolism-related enzyme activities and metabolites obtained from identical samples in a previous study. SO-KO plants exhibited remarkable and broad regulative responses at the mRNA level, especially in transcripts related to sulfur metabolism enzymes, but also in those related to stress response and senescence. Focusing on SO regulation, no alterations were detectable in the WT, whereas in SO-KO plants we found up-regulation of two splice variants of the SO gene, although this gene is not functional in this line. Our data provide evidence for the highly specific coregulation between SO and sulfur-related enzymes like APS reductase, and suggest two novel candidates for involvement in SO2 detoxification: an apoplastic peroxidase, and defensins as putative cysteine mass storages

Developmental changes in the potential for H2S emission in cucurbit plants

Based on results obtained with leaf discs exposed to sulfate, leaves on cucurbit plants (Cucurbita pepo L. cv Small Sugar Pumpkin and Cucumis sativus cv Chipper) 1 to 2.5 weeks old have a low potential for H2S emission (less than 10 picomoles per min per square cm leaf area) in response to sulfate, whereas discs from most of the leaves on plants 3 to 4 weeks old emit Hs2S at a higher rate (50 to 150 picomoles per min per square cm leaf area). This difference is determined by the age of the plant, and is independent of the leaves' age or developmental stage. In response to L-cysteine, however, discs from leaves on cucurbit plants 1 to 2.5 weeks and old emit H2S at higher rates (15 to 50 picomoles per min per square cm leaf area) than in response to sulfate. Furthermore, the potential for H2S emission in response to L-cysteine decreases with increasing age of the individual leaf. Thus, most of the potential for H2S emission in response to L-cysteine is developed during germination and th e early growth of cucurbit plants, but most of the potential for H2S emission in response to sulfate arises later in the development of the plants. The development changes in the potential for H2S emission in response to L-cysteine in vivo are paralleled by changes in the cysteine desulfhydrase activity extractable from the leaves. This extractable activity, which is thought to be responsible for the generation of H2S by leaf tissue in response to L-cysteine, can be increased by preincubation of leaf discs in L-cysteine. (IFU