Project description:The toxin ricin has been shown to cause inflammatory lung damage, leading to pulmonary oedema and, at higher doses, mortality. In order to understand the genetic basis of this inflammatory cascade a custom microarray platform (1509 genes) directed towards immune and inflammatory markers was used to investigate the temporal expression profiles of genes in a Balb/c mouse model of inhalational ricin exposure. To facilitate examination of those genes involved in both inflammatory cascades and wound repair the dose which was investigated was sub-lethal across a 96 hour time course. Histopathology of the lung was mapped across the time course and genetic responses considered in the context of overall lung pathology. 685 genes were found to be statistically significantly different compared to controls, across the time course and these genes have been investigated in the context of their biological function in ricin poisoning. As well as confirming key inflammatory markers associated with ricin intoxication (TNFa and Il1b) several pathways that are altered in expression were identified following pulmonary exposure to ricin. These genes included those involved in cytokine-cytokine signalling cascades (IL1, IL1r, IL1r2, Ccl 4, 6, 10), focal adhesion (Fn1, ICAM1) and tissue remodelling (VEGF, Pim1). Furthermore, the observed alteration in expression of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) indicates a key role in membrane integrity and cellular adhesion in ricin poisoning. Data captured using this transcriptomic approach could be used to develop a specific approach to the treatment of inhalational ricin exposure. This work was conducted as part of a wider programme of work to compare a number of militarily relevant lung damaging agents, with a view to establishing a rational basis for the identification of more generic medical countermeasures. Four groups of six mice were exposed to ricin and a further groups exposed to vehicle only control (PBS). Following exposure mice were culled at 6 timepoints (1, 4, 7, 24, 48 and 96h). RNA was extracted and run on the custom array.
Project description:The toxin ricin has been shown to cause inflammatory lung damage, leading to pulmonary oedema and, at higher doses, mortality. In order to understand the genetic basis of this inflammatory cascade a custom microarray platform (1509 genes) directed towards immune and inflammatory markers was used to investigate the temporal expression profiles of genes in a Balb/c mouse model of inhalational ricin exposure. To facilitate examination of those genes involved in both inflammatory cascades and wound repair the dose which was investigated was sub-lethal across a 96 hour time course. Histopathology of the lung was mapped across the time course and genetic responses considered in the context of overall lung pathology. 685 genes were found to be statistically significantly different compared to controls, across the time course and these genes have been investigated in the context of their biological function in ricin poisoning. As well as confirming key inflammatory markers associated with ricin intoxication (TNFa and Il1b) several pathways that are altered in expression were identified following pulmonary exposure to ricin. These genes included those involved in cytokine-cytokine signalling cascades (IL1, IL1r, IL1r2, Ccl 4, 6, 10), focal adhesion (Fn1, ICAM1) and tissue remodelling (VEGF, Pim1). Furthermore, the observed alteration in expression of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) indicates a key role in membrane integrity and cellular adhesion in ricin poisoning. Data captured using this transcriptomic approach could be used to develop a specific approach to the treatment of inhalational ricin exposure. This work was conducted as part of a wider programme of work to compare a number of militarily relevant lung damaging agents, with a view to establishing a rational basis for the identification of more generic medical countermeasures.
Project description:For the purpose of establishing a mice model for sever COVID-19 , mice were infected intranasally with SARS-CoV-2 two days after pulmonary application of low-dose ricin. The goal of this study is to perform a comparative transcriptomic analysis by exploring the alterations in gene expression in lungs of mice exposed to low-dose ricin and SARS-CoV-2 (samples OR009-OR012) compared to lungs of mice infected solely with SARS-CoV-2 (48 hr after infection, samples OR021-OR024) or mice exposed to low-dose ricin (96 hr post exposure,samples OR005-OR008)) or mice exposed to lethal dose of ricin (48 hr post exposure, samples OR013-OR016). Methods: Total RNA was extracted from lungs of ricin intoxicated mice (intranasally exposure to 1.7 µg/kg or 10 µg/kg ricin ) or of SARS-CoV-2 infected mice (intranasal administration of 5 x 106 PFU), using the RNeasy mini kit (Qiagen). RNA-seq libraries were constructed and sequencing of 100bp paired-end was performed on the Illumina NovaSeq 6000 system. Sequencing yielded about 22M reads per sample that were mapped to the mouse genome. RNA ratios were clustered using partitioning clustering. We next carried out Ingenuity Pathway Analysis (IPA). Results: Principal component analysis revealed distinct transcriptional signatures between lungs mice exposed to low-dose ricin and infected with SARS-CoV-2 compared to lungs of mice infected solely with SARS-CoV-2 or mice exposed to low-dose ricin (96 hr post exposure) or mice exposed to lethal dose of ricin (48 hr post exposure). Differentially Expressed Genes (DEGs) were defined as such when having false discovery rate (FDR) value (p-adjusted) of ≤ 0.01 and a fold change (FC) of ≥ 1.5 or ≤ 0.66. Analysis of Low-dose-ricin-treated mice transcripts resulted in the detection of 6684 DEGs, 55% upregulated and 45% downregulated. Similarly, in Low-dose-ricin-treated mice infected with SARS-CoV-2, we found a total of 6044 differentially expressed genes, 52% induced and 48% repressed. Considerably fewer (797, 67% upregulated and 33% downregulated) differentially expressed genes were identified in lungs of mice infected only with SARS-CoV-2.
Project description:Ricin is a potential bioweapon because of its toxicity, availability, and ease of production. When delivered to the lungs, ricin causes severe pulmonary damage with symptoms that are similar to those observed in acute lung injury and adult respiratory distress syndrome. The airway epithelium plays an important role in the pathogenesis of many lung diseases, but its role in ricin intoxication has not been elucidated. Exposure of cultured primary human airway epithelial cells to ricin resulted in the activation of stress-activated protein kinases (SAPKs) and NF-κB and in the increased expression of multiple proinflammatory molecules. Among the genes upregulated by ricin and identified by microarray analysis were those associated with transcription, nucleosome assembly, inflammation, and response to stress. Sequence analysis of the promoters of these genes identified NF-κB as one of the transcription factors whose binding sites were over-represented. Although airway cells secrete TNF-α in response to ricin, blocking TNF-α did not prevent ricin-induced activation of NF-κB. Inhibition of p38 MAPK by a chemical inhibitor and NF-κB by short interfering RNA resulted in a marked reduction in the expression of proinflammatory genes, demonstrating the importance of these two pathways in ricin intoxication. Therefore, the p38 MAPK and NF-κB pathways are potential therapeutic targets for reducing the inflammatory consequences of ricin poisoning. Experiment Overall Design: Control RNA from untreated primary human airway cells was compared to RNA from ricin-treated airway cells
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility.
Project description:Ricin is a potential bioweapon because of its toxicity, availability, and ease of production. When delivered to the lungs, ricin causes severe pulmonary damage with symptoms that are similar to those observed in acute lung injury and adult respiratory distress syndrome. The airway epithelium plays an important role in the pathogenesis of many lung diseases, but its role in ricin intoxication has not been elucidated. Exposure of cultured primary human airway epithelial cells to ricin resulted in the activation of stress-activated protein kinases (SAPKs) and NF-κB and in the increased expression of multiple proinflammatory molecules. Among the genes upregulated by ricin and identified by microarray analysis were those associated with transcription, nucleosome assembly, inflammation, and response to stress. Sequence analysis of the promoters of these genes identified NF-κB as one of the transcription factors whose binding sites were over-represented. Although airway cells secrete TNF-α in response to ricin, blocking TNF-α did not prevent ricin-induced activation of NF-κB. Inhibition of p38 MAPK by a chemical inhibitor and NF-κB by short interfering RNA resulted in a marked reduction in the expression of proinflammatory genes, demonstrating the importance of these two pathways in ricin intoxication. Therefore, the p38 MAPK and NF-κB pathways are potential therapeutic targets for reducing the inflammatory consequences of ricin poisoning. Keywords: Comparative genomic hybridization