Project description:Background: Previously, we reported that perfluorooctanoic acid (PFOA) promotes liver cancer in manner similar to that of 17β-estradiol (E2) in rainbow trout. Also, other perfluoroalkyl acids (PFAAs) are weakly estrogenic in trout and bind the trout liver estrogen receptor (ER). Objectives: The primary objective of this study was to determine whether multiple PFAAs enhance hepatic tumorigenesis in trout, an animal model that represents human insensitivity to peroxisome proliferators. Methods: A two-stage chemical carcinogenesis model was employed in trout to evaluate PFOA, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorooctane sulfonate (PFOS) and 8:2 fluorotelomer alcohol (8:2FtOH) as complete carcinogens or promoters of aflatoxin B1 (AFB1)- and/or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced liver cancer. A custom trout DNA microarray was used to assess hepatic transcriptional response to these dietary treatments in comparison to E2 and the classic peroxisome proliferator clofibrate (CLOF). Results: Incidence, multiplicity and size of liver tumors in trout fed diets containing E2, PFOA, PFNA and PFDA were significantly higher compared to AFB1-initiated animals fed control diet, whereas PFOS caused a minor increase in liver tumor incidence. E2 and PFOA also enhanced MNNG-initiated hepatocarcinogenesis. Pearson correlation analyses, unsupervised hierarchical clustering and principal components analyses showed that the hepatic gene expression profiles for E2 and PFOA, PFNA, PFDA and PFOS were overall highly similar, though distinct patterns of gene expression were evident for each treatment, particularly for PFNA. Conclusions: Overall, these data suggest that multiple PFAAs can promote liver cancer and that the mechanism of promotion may be similar to that for E2.
Project description:Background: Previously, we reported that perfluorooctanoic acid (PFOA) promotes liver cancer in manner similar to that of 17β-estradiol (E2) in rainbow trout. Also, other perfluoroalkyl acids (PFAAs) are weakly estrogenic in trout and bind the trout liver estrogen receptor (ER). Objectives: The primary objective of this study was to determine whether multiple PFAAs enhance hepatic tumorigenesis in trout, an animal model that represents human insensitivity to peroxisome proliferators. Methods: A two-stage chemical carcinogenesis model was employed in trout to evaluate PFOA, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorooctane sulfonate (PFOS) and 8:2 fluorotelomer alcohol (8:2FtOH) as complete carcinogens or promoters of aflatoxin B1 (AFB1)- and/or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced liver cancer. A custom trout DNA microarray was used to assess hepatic transcriptional response to these dietary treatments in comparison to E2 and the classic peroxisome proliferator clofibrate (CLOF). Results: Incidence, multiplicity and size of liver tumors in trout fed diets containing E2, PFOA, PFNA and PFDA were significantly higher compared to AFB1-initiated animals fed control diet, whereas PFOS caused a minor increase in liver tumor incidence. E2 and PFOA also enhanced MNNG-initiated hepatocarcinogenesis. Pearson correlation analyses, unsupervised hierarchical clustering and principal components analyses showed that the hepatic gene expression profiles for E2 and PFOA, PFNA, PFDA and PFOS were overall highly similar, though distinct patterns of gene expression were evident for each treatment, particularly for PFNA. Conclusions: Overall, these data suggest that multiple PFAAs can promote liver cancer and that the mechanism of promotion may be similar to that for E2. A total of 40 samples were analyzed using a a dye-swap, reference sample hybridization protocol. Rainbow trout were exposed to the following experimental treatments via the diet for two weeks (number in parenthesis is assigned group #): (1) Control; (2) 5 mg/kg diet estradiol (E2); (3) 2000 mg/kg diet perfluorooctanoic acid (PFOA); (4) 2000 mg/kg diet perfluorononanoic acid (PFNA); (5) 2000 mg/kg diet perfluorodecanoic acid (PFDA); (6) 200 mg/kg diet perfluorooctane sulfonate; (7) 2000 mg/kg 8:2 fluorotelomer alcohol (FTOH); and (8) 2000 mg/kg diet clofibrate. A total of 40 total hepatic mRNA samples were analyzed using a dye-swap, reference sample hybridization protocol. A reference RNA pool was made by combining equal amounts of RNA from all control RNA samples, with one exception. A separate time-matched reference pool was utilized for group 6 samples (PFOS treatment). Five hybridizations were performed for each treatment group in the following pattern: Replicate A Cy5/Reference Cy3; Replicate A Cy3/Reference Cy 5; Replicate B Cy5/Reference Cy3; Replicate B Cy3/Reference Cy5; Replicate C Cy5/Reference Cy3. Thus, the experiment consisted of three biological replicates, for two of which were replicated technically.
Project description:Transcriptional profiling of rainbow trout liver cells comparing liver cells from small fish with liver cells from large fish at two time periods.
Project description:Transcriptional profiling of rainbow trout muscle cells comparing muscle cells from small fish with muscle cells from large fish at two time periods.
Project description:Stocking density is considered as a key factor determining the productivity of fish aquaculture systems. The transcriptomic response to crowding stress is, however, still poorly investigated. We aimed at the identification of potential biomarker genes via microarray analyses to get insight into molecular pathways modulated through density-induced stress in farmed rainbow trout Oncorhynchus mykiss. Transcriptome profiling in liver, kidney, and gills was complemented with behaviarol observation and analysis of classical plasma parameters. Individuals of two trout strains were exposed for eight days to definite stocking densities, 1 kg/m³ (low density); 10 kg/m³ (moderate); 18 kg/m³ (elevated); and 35 kg/m³ (high). Whereas stocking density had no significant effect on cortisol levels, plasma glucose levels were elevated in trout kept at high density. Pathway enrichment analyses confirmed the upregulation of HIF1a signaling in liver contributing to glucose homeostasis during stress conditions, while mTOR and PI3K/AKT signaling pathways were downregulated. Further perturbed hepatic pathways were involved in protein ubiquitination and the biosynthesis of cholesterol, retinol and glutathione. Three stocking density conditions were investigated: an uncrowded âmoderateâ density (MD: 10 kg trout/m³) , an elevated density (ED: 18 kg/m³ ), and high density (HD: 35 kg/m³). The experiment was performed twice with two strains of Steelhead rainbow trout (Troutlodge and Born trout), randomly assigned to identical glass tanks with MD (30 and 34 individuals), ED (60 and 64 individuals), and HD (120 and 140 individuals). Trout were sampled 8 d after experimental onset.
Project description:Purpose:Our data significantly advance understanding of heat stress regulatory mechanism of miRNA in the head kidney of rainbow trout Methods:miRNAs of rainbow trout were involved in heat stress were identified by high-throughput sequencing of six small RNA libraries of the kidney tissues under control (18℃) and heat-treated (24℃) conditions Results:high-throughput sequencing was performed to identify miRNAs responsive to heat stress. We obtained 41,991,119 and 43,882,123 raw reads and 39,756,736 and 42,538,331 clean reads from under control (18℃) and heat-treated (24℃) .A total of 392 conserved miRNAs and 989 novel miRNAs were identified, of which 78 miRNAs were expressed in different response to heat stress. In addition to, including 393 negative correlation miRNA-target gene pairs Conclusions:through high-throughput sequencing of the six libraries from head kidney tissue of rainbow trout, the expression level of miRNA has significant changes after heat stress.
Project description:Transcriptional profiling of rainbow trout liver and muscle cells comparing small fish with large fish within a population of neomale offspring.