Project description:Pharmaceutical chemicals used in human medicine are released into surface waters via municipal effluents and pose a risk for aquatic organisms. Among these substances are selective serotonin reuptake inhibitors (SSRIs) which can affect aquatic organisms at sub ppb concentrations. To better understand biochemical pathways influenced by SSRIs, evaluate changes in the transcriptome, and identify gene transcripts with potential for biomarkers of exposure to SSRIs; larval zebrafish Danio rerio were exposed (96 h) to two concentrations (25 and 250 µg/L) of the SSRIs, fluoxetine and sertraline, and changes in global gene expression were evaluated (Affymetrix GeneChip® Zebrafish Array). Significant changes in gene expression (>=1.7 fold change, p<0.05) were determined with Partek® Genomics Suite Gene Expression Data Analysis System and ontology analysis was conducted using Molecular Annotation System 3. The number of genes differentially expressed after fluoxetine exposure was 288 at 25 µg/L and 131 at 250 µg/L; and after sertraline exposure was 33 at 25 µg/L and 52 at 250 µg/L. Five genes were differentially regulated in all treatments relative to control, suggesting that both SSRIs share some similar molecular pathways. Among them, expression of the gene coding for FK506 binding protein 5 (FKBP5), which is annotated to stress response regulation, was highly down-regulated in all treatments (results confirmed by qRT-PCR). Gene ontology analysis indicated that regulation of stress response and cholinesterase activity were critical functions influenced by these SSRIs, and suggested that changes in the transcription of FKBP5 or acetylcholinesterase could be useful biomarkers of SSRIs exposure in wild fish. Zebrafish (Danio rerio) were obtained from the Zebrafish Research Facility maintained at the Center for Environmental Biotechnology at the University of Tennessee. Fish husbandry, spawning, and experimental procedures were conducted with approval from the UT Insititutional Animal Care and Use Committee (Protocol #1690-1007). Water for holding fish and conducting experiments (hereafter referred to as fish water) consisted of MilliQ water (Millipore, Bedford, MA) with ions added: 19 mg/L NaHCO3, 1 mg/L sea salt (Instant Ocean Synthetic Sea Salt, Mentor, OH), 10 mg/L CaSO4, 10 mg/L MgSO4, 2 mg/L KCl. Embroyos were obtained by spawning adult fish with no history of contaminant exposure. Fertilization of embryos took place at the same time (<15 minutes), such that larvae used in experiments were of similar age at the time of exposure. All activities (maintenance of adult fish, spawning, and experiments) were conducted in an environmental chamber with a temperature of 27 +/- 1 C and 14:10h light:dark photoperiod. Larval zebrafish (72 hpf) were exposed for 96 h in 200ml fish water containing appropirate amount of SSRI stock (i.e. fluoxetine or sertraline). There were four SSRIs treatments (25 and 250 ug/L fluoxetine and 25 and 250 ug/L sertraline) and one control (no SSRIs) with triplicate beakers and each beaker contained about 100 larval fish. During exposure for 96 hours, beakers were kept covered to prevent water evaporation and fish were not fed (i.e., fish consumed their yolk sac).
Project description:To identify molecular effects of the antineoplastic agent PKC412 (Midostaurin), we applied gene expression profiling in zebrafish using whole genome microarrays. Zebrafish eleuthero-embryos were exposed for 6 dpf to nominal levels of 2 μg/L and 40 μg/L PKC412. Among the 259 and 511 altered transcripts at both concentrations, respectively, the expressions of genes involved in the circadian rhythm were of interest. Alteration of swimming behaviour was not noted. Pathways of interest affected by PKC412 were angiogenesis, apoptosis, DNA damage response and response to oxidative stress. Angiogenesis was not altered by PKC412 treatment at both concentrations. Apoptosis occurred in olfactory placodes of embryos exposed to 40 μg/L, and DNA damage was induced at both PKC412 concentrations. However, there were no significant effects on reactive oxygen species formation. This study leads to the conclusion that PKC412-induced alterations of gene transcripts are partly paralleled by physiological effects at high, but not at low PKC412 concentrations expected to be of environmental relevance. Gene expression in zebrafish eleuthero-embryos was measured after exposure for 6dpf to 2 ug/L and 40 ug/L PKC412 or to the respective controls. A total of 12 arrays (Agilent 4 × 44 K Zebrafish microarray) were used, including four for the water control group, four for the solvent control group, four for the 2 μg/L and four for the 40 μg/L PKC412 dose group.
Project description:To identify molecular effects of the antineoplastic agent PKC412 (Midostaurin), we applied gene expression profiling in zebrafish using whole genome microarrays. Zebrafish eleuthero-embryos were exposed for 6 dpf to nominal levels of 2 μg/L and 40 μg/L PKC412. Among the 259 and 511 altered transcripts at both concentrations, respectively, the expressions of genes involved in the circadian rhythm were of interest. Alteration of swimming behaviour was not noted. Pathways of interest affected by PKC412 were angiogenesis, apoptosis, DNA damage response and response to oxidative stress. Angiogenesis was not altered by PKC412 treatment at both concentrations. Apoptosis occurred in olfactory placodes of embryos exposed to 40 μg/L, and DNA damage was induced at both PKC412 concentrations. However, there were no significant effects on reactive oxygen species formation. This study leads to the conclusion that PKC412-induced alterations of gene transcripts are partly paralleled by physiological effects at high, but not at low PKC412 concentrations expected to be of environmental relevance.