Project description:The excessive perchlorate utilization as an oxidizer in rocket propellants and blasting agents had led to the contamination of surface and ground waters. This chemical is known to compete with iodine for binding to the thyroid membrane receptors potentially causing hypothyroidism and fetal retardation in pregnant women. Nevertheless, to date, its biological effects are not completely understood. We have investigated the molecular mechanisms responsive to perchlorate in the nematode C. elegans to nominate a candidate gene for further peruse in the development of a C.elegans perchlorate biosensor. Perchlorate (1 mg/mL) affected the transcriptional response of Regulation of developmental process, growth, defense mechanisms and stress response, among other biological processes.
Project description:Arsenic and mercury are known chemical hazards. The differences in effects from organic and inorganic forms of these toxic elements is less well understood, however. The nematode Caenorhabditis elegans (C. elegans) is a suitable model to investigate the toxicity of environmental hazards. In this study, the transcriptomic profiles of C. elegans exposed to inorganic mercury chloride (HgCl2) and sodium (meta)arsenite (NaAsO2) were assessed alongside organic methylmercury chloride (meHgCl) and dimethylarsinic acid (DMA). For this purpose, adult C. elegans were exposed for 24 h to NaAsO2 (10 µg/ml), DMA (200 µg/ml), HgCl2 (2 µg/ml), and meHgCl (0.5 µg/ml), concentrations that were equitoxic in juveniles for developmental delay. Whole genome gene expression profiles were determined by using Cellegans_UnrestrictedGE_G2519F_020186 Microarray (Agilent Technologies, Santa Clara, CA). The results showed significant changes in the transcriptome of adult C. elegans exposed to NaAsO2, DMA, HgCl2, or meHgCl relative to the control group (C. elegans treated with water). A total of 927 and 1221 differentially expressed genes (DEGs) were found in C. elegans treated with 10 µg/ml NaAsO2 or 200 µg/ml DMA, respectively. Interestingly, only 161 DEGs were in common for these two chemicals. Exposure to 2 µg/ml HgCl2 or 0.5 µg/ml meHgCl altered the expression of 670 and 485 genes, respectively, and out of these genes, 154 were commonly altered by the two treatments. Analysis of DEGs revealed that organic and inorganic forms of arsenic and mercury have different effects on the transcriptome of adult C. elegans.
Project description:Polycyclic aromatic hydrocarbons (PAHs) are abundant organic compounds and are anthropogenically produced by the incomplete combustion of organic matter (e.g. fossil fuels and tobacco smoke). One notable model PAH is benzo[a]pyrene (BaP), which is listed as a Group 1 human carcinogen by the International Agency of Research on Cancer (IARC). Although the mode of action for BaP is well known in higher organisms, limited knowledge is available regarding the consequence of BaP exposure in the model organism Caenorhabditis elegans. The objective of this study was to define the the global transcriptome of wild-type C. elegans exposed to BaP (0, 5 and 20 μM). The most responsive transcripts were linked to redox processes and xenobiotic responses, including P450 enzymes (CYPs) (mainly members of the CYP35 family), epoxide hydrolases (EHs), glutathione S-transferases (GSTs), and UDP-glucuronosyltransferases (UGTs), all of which are linked to the metabolism (phase I & II) of xenobiotic substances. In summary, although the dominant CYP1A1/2 & CYP1B1 metabolic pathway is absent in C. elegans, BaP still induced a strong transcriptomic response. This provides strong evidence that parallel pathway(s) are implicated in BaP metabolism, and possibly, in its detoxification.
Project description:Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are currently being investigated for a range of biomedical applications. Their use have been related with different cytotoxic mechanisms including the generation of oxidative stress and the induction of metal detoxification pathways, among others. We have investigated the molecular mechanisms responsive to in-house fabricated citrate coated SPIONs (C-SPIONs) in the nematode C. elegans to compare in vivo findings with previous in vitro studies. C-SPIONs (500 µg/ml) affected the transcriptional response of signal transduction cascades (i.e. TFG-beta), protein processing in the endoplasmic reticulum, and RNA transport, among other biological processes. They also triggered a lysosomal response, indicating a relevant biological role of this cellular compartment in the response to this nanoparticle treatment in C. elegans. Interestingly, other pathways frequently linked to nanotoxicity like oxidative stress or apoptosis were not identified as significantly affected in this genome-wide in vivo study despite the high dose of exposure.
Project description:Sodium benzoate is a widely used food antimicrobial in drinks and fruit juices. A microarray study was conducted to determine the transcriptional response of Escherichia coli O157:H7 to 0.5% (w/v) sodium benzoate. Stationary phase E. coli O157:H7 grown in 150 ml Luria-Bertani broth (LB) was exposed to 0 (control) and 0.5% sodium benzoate. Each treatment was duplicated and sampled at 0 (immediately after exposure), 5, 15, 30, and 60 min. Total RNA was extracted and analyzed with E. coli 2.0 Gene Chips.
Project description:This SuperSeries is composed of the following subset Series: GSE36413 : C. elegans young adults : Exposed to Bacillus thuringiensis DB27 vs. E. coli OP50 exposure; 4hours GSE36493: C. elegans young adults: Exposed to Staphylococcus aureus versus exposed to E. coli OP50 : 4 hours GSE36499: C. elegans young adults: Exposed to Serratia marcescens versus exposed to E. coli OP50 : 4 hours GSE36501: C. elegans young adults: Exposed to Xenorhabdus nematophila versus exposed to E. coli OP50 : 4 hours GSE36517: P. pacificus young adults: Exposed to Bacillus thuringiensis DB27 versus exposed to E. coli OP50 : 4 hours GSE36519: P. pacificus young adults: Exposed to Staphylococcus aureus versus exposed to E. coli OP50 : 4 hours GSE36521: P. pacificus young adults: Exposed to Serratia marcescens versus exposed to E. coli OP50 : 4 hours GSE36523: P. pacificus young adults: Exposed to Xenorhabdus nematophila versus exposed to E. coli OP50 : 4 hours Refer to individual Series
Project description:Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are currently being investigated for a range of biomedical applications. Their use have been related with different cytotoxic mechanisms including the generation of oxidative stress and the induction of metal detoxification pathways, among others. Different NP coatings are being explored, among them albumin which has been applied in some drugs delivery systems. We have investigated the molecular mechanisms responsive to in-house fabricated SPIONs coated with bovine serum albumin (BSA-SPIONs) in the nematode C. elegans to compare in vivo findings with previous in vitro studies. BSA-SPIONs (500 µg/ml) affected the transcriptional response of glycan metabolic pathways related to innate immune response, xenobiotics degradation, and triggered a lysosomal response, indicating a relevant biological role of this cellular compartment in the response to this nanoparticle treatment in C. elegans. Remarkably, key biological functions such as apoptosis or protein processing were not affected with significance despite the high dose of exposure.