Project description:The rat has been used extensively as a model for evaluating chemical toxicities and for understanding drug mechanisms. However, its transcriptome across multiple organs, or developmental stages, has not yet been reported. Here we show, as part of the SEQC consortium efforts, a comprehensive rat transcriptomic BodyMap created by performing RNASeq on 320 samples from 11 organs of both sexes of juvenile, adolescent, adult and aged Fischer 344 rats. We catalogue the expression profiles of 40,064 genes, 65,167 transcripts, 31,909 alternatively spliced transcript variants and 2,367 non-coding genes/non-coding RNAs (ncRNAs) annotated in AceView. We find that organ-enriched, differentially expressed genes reflect the known organ-specific biological activities. A large number of transcripts show organ-specific, age-dependent or sex-specific differential expression patterns. We create a web-based, open-access rat BodyMap database of expression profiles with crosslinks to other widely used databases, anticipating that it will serve as a primary resource for biomedical research using the rat model. We constructed a comprehensive RNA-Seq data set for studying the dynamics of the rat transcriptome using 320 RNA samples isolated from 11 organs (adrenal gland, brain, heart, kidney, liver, lung, muscle, spleen, thymus, and testes or uterus) from both sexes of Fischer 344 rats across four developmental stages (2-, 6-, 21-, and 104-weeks-old). Four biological replicates were used for each of the 80 sample groups.
Project description:Kidney miRNA expression was examined in F344 rats at 2, 5, 6, 8, 15, 21, 78, and 104 weeks of age in both sexes using Agilent miRNA microarrays. 311 miRNAs were found to be expressed in at least one age and sex. Filtering criteria of ?1.5 fold change and ANOVA (FDR <5%) revealed 174 differentially expressed miRNAs in the kidney; 173 and 34 miRNAs exhibiting age and sex effects, respectively. Principal component analysis revealed age effects predominated over sex effects, with 2 week miRNA expression being much different from other ages. No significant sexually dimorphic miRNA expression was observed from 5 to 8 weeks, while the most differential expression (13 miRNAs) was observed at 21 weeks. Potential target genes of these differentially expressed miRNAs were identified. Pathway analysis was used to investigate the possible roles of these target genes in age- and sex-specific differences. Untreated male and female F344 rats from 2, 5, 6, 8, 15, 21, 78, and 104 weeks of age (n=5) were sacrificed by CO2 asphyxiation, whole kidneys collected and homogenized, total RNA, including small RNA fraction, was used for miRNA expression arrays (Agilent).
Project description:The kidney is important for a number of physiological processes including blood filtering, blood pressure regulation and proper excretion of many drugs and xenobiotics. Age is a predisposing condition for susceptibility to chronic kidney disease and progression as well as acute kidney injury that may arise due to the adverse effects of some drugs. Age-related differences in kidney biology, therefore, are a key concern in understanding drug safety and disease progression. We hypothesize that the underlying suite of genes expressed in the kidney at various life cycle stages will impact susceptibility to adverse drug reactions. Therefore, establishing changes in baseline expression data between these life stages is the first and necessary step in evaluating this hypothesis. Untreated male F344 rats from 2, 5, 6, 8, 15, 21, 78, and 104 weeks of age (n=5) were sacrificed by CO2 asphyxiation, whole kidneys collected and homogenized, total RNA used for whole genome expression arrays (Agilent).
Project description:The kidney functions in key physiological processes to filter blood and regulate blood pressure via key molecular transporters and ion channels. Sex-specific differences have been observed in renal disease incidence and progression as well as acute kidney injury in response to certain drugs. Although advances have been made in characterizing the molecular components involved in various kidney functions, the molecular mechanisms responsible for sex differences are not well understood. We hypothesized that the basal expression levels of genes involved in various kidney functions throughout the life cycle will influence sex-specific susceptibilities to adverse renal events. Untreated female F344 rats from 2, 5, 6, 8, 15, 21, 78, and 104 weeks of age (n=5) were sacrificed by CO2 asphyxiation, whole kidneys collected and homogenized, total RNA used for whole genome expression arrays (Agilent).
Project description:Preclinical biomarkers useful for identification of idiosyncratic drugs have not been identified. It is hypothesized that patterns of transcript expression for the hepatotoxicants, including classical and idiosyncratic hepatotoxicants, are similar and the patterns differ from those of non-hepatotoxicants. This experiment is part of the biomarkers study, and focus on two clasical hepatotoxicants: Acetaminophen and Carbon tetrachloride. We have employed whole genome microarray expression profiling to identify liver gene expression changes induced by hepatotoxicants. For the same animal, urinary microRNA profiling were analyzed. APAP and CCl4 both significantly increased the urinary levels of 44 and 28 miRNAs, respectively. In addition, 10 of the increased miRNAs were in common between APAP and CCl4. Computational analysis was used to predict target genes of the 10 shared hepatotoxicant-induced miRNAs. From the same animals, liver gene expression profiling was performed using whole genome microarrays. Eight putative target genes were found to be significantly altered in the liver of APAP and CCl4 treated animals. Acetaminophen induced liver gene expression changes in rats (Six to seven week-old male Sprague-Dawley rats, provided by the US Food and Drug Administration National Center for Toxicological Research (NCTR) breeding colonies, were used for the study.) were measured at 6 hours, 24 hours, 3 days and 7 days after exposure to doses of 0, 100 and 1250 mg/kg. Carbon tetrachloride induced liver gene expression changes in rats were measured at 6 hours, 24 hours and 3 days after exposure to doses of 0, 50 and 2000 mg/kg. Each group has at least 4 animals, total of 96 samples.
Project description:The widely used rat uterotrophic assay to assess known and potential estrogenic compounds only considers uterine weight gain as endpoint measurement. To complement this method with an advanced technology that reveals molecular targets, we analyzed changes in protein expression using label-free quantitative proteomics by liquid chromatography–mass spectrometry on a high resolution (Orbitrap) instrument. Our samples were uterine protein extracts of ovariectomized rats after daily 17β-estradiol exposure for five days in comparison with those of vehicle-treated control animals. The study revealed that __ uterine proteins significantly regulated by estrogen treatment, and crucial findings were verified using multiple reaction monitoring-based targeted proteomics. When mapped by pathway analyses, estrogen-regulated proteins represented cell death and survival, cellular movement and protein synthesis as top molecular and cellular functions, and networks were found with the presence of nuclear estrogen receptor(s) as a prominent molecular node confirmed the relevance of our findings to hormone-associated events.
Project description:The 6-hydroxydopamine (6OHDA) rat model of parkinsonism is among the first, and most commonly used, animal models of Parkinson’s disease. It provides insight into the compensatory changes that occur in the brain after dopamine (DA) neuron degeneration. In order to better define the consequences of substantia nigra DA neuron loss on the neural and glial populations during and following nigrostriatal degeneration, tissue was collected and evaluated from the substantia nigra of 6OHDA or vehicle treated, or naïve rats at 1, 2, 4, 6 & 16 weeks. Comprehensive gene expression analysis was conducted to detect significant differences in gene expression. Comparisons were conducted within the same treatment groups over time as well as across treatments within the same post-treatment interval. Longitudinal expression patterns were parsed using a k-means clustering algorithm as a method for finding patterns indicative of neuronal loss, upregulation in response to lesion or surgical damage exclusive of lesion. Tissue was collected from the substantia nigra of 6OHDA treated, sham and naïve rats at 1, 2, 4, 6 & 16 weeks post-treatment. A unilateral striatal lesion was employed that results in a 99% striatal DA reduction and an 80% loss of DA neurons in the substantia nigra. 6OHDA lesions were confirmed via catecholamine quantitation by HPLC. RNA integrity was assessed with an Agilent 2100 Bioanalyzer with minimum RIN acceptance criteria of 8.0. Multidimensional plots and Pearson Correlations were used to establish group/treatment homogeneity. Tissue was subjected to comprehensive gene expression analysis using the Affymetrix Rat Gene 1.0ST array.
Project description:MYC is a pleiotropic transcription factor that regulates numerous pathways and whose deregulation promotes cancer. Myc+/- mice have extended lifespan relative to their wild type littermates. To better understand the effects of the Myc+/- genotype on cellular processes, microarrays were performed on young (5 month) and old (24 month) Myc+/- and WT males in liver, skeletal muscle, and adipose tissues. Microarray data were used to compare the effects of aging with the effects of the Myc+/- genotype at each age, to identify pathways enriched for differentially expressed genes, and to compare the Myc+/- gene expression signature with that from other long-lived mice. Male mice of each genotype (Myc+/- and wild type) were sacrificed at 5 months and 24 months of age, and tissues were harvested and snap frozen in liquid nitrogen. RNA was extracted, and pooled between 5-8 mice within each cohort, creating one pooled sample for each combination of age, genotype, and tissue. Three technical replicates were run for each sample.
Project description:Cardiovascular disease (CVD) is the leading cause of mortality, with sex and age being strong risk factors. Mitochondria are vital for normal cardiac function, and regulation of mitochondrial structure and function may impact susceptibility to CVD. We analyzed the basal expression levels of mitochondria-related genes in the hearts of male and female untreated control rats at different ages to identify potential role of mitochondria in differential susceptibility to CVD between the sexes. Hearts from 5 male and 5 female rats at three different ages (young (8-week), adult (21-week), and old (78-week)) were used for investigation of sex-related differences in expression levels of genes. At each age, rats were humanely euthanized by CO2 asphyxiation and whole hearts were removed quickly, flash frozen in liquid nitrogen, and stored at -80ËC until further investigation. The frozen hearts were individually ground into powder in liquid nitrogen using a mortar and pestle chilled on dry ice. Total RNAs were extracted from heart tissue powder and gene expression was measured using Agilent Rat Whole Genome Microarrays (4 x 44k format; Agilent Technologies, Inc.).