Toxicogenomic Study of Pentamethylchromanol (PMCol)
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ABSTRACT: The objective of this study is to determine the molecular mechanisms of PMCol-induced hapatotoxicity using microarray The study demonstrated that chronic exposure to high doses of PMCol induces liver damage and dysfunction, probably due to both inhibition of synthesis and depletion of liver glutathione as well as modification of other drug metabolism pathways. PMCol was administered to male Sprague-Dawley rats at at doses of 200 and 2000 mg/kg daily for 7 or 28 days
Project description:OBJECTIVE: To study the genetic regulatory mechanisms in the remote zone of left ventricular (LV) free wall in order to partly explain the more frequent progression to heart failure after acute myocardial infarction (AMI) in diabetic rats. METHODS: 10 weeks after diabetes mellitus (DM) induction with Streptozotocin (STZ), the left anterior descending coronary arteries of uncontrolled diabetic Sprague-Dawley (SD) rats and non-diabetic ones were ligated without reperfusion. Then, the remote zone tissues of LV free wall were taken as samples at day 1, 7, 14, 28, and 56 post AMI. Significant different expression genes were filterd from Affymetrix Genechip U230 2.0 array by GCOS software. Genetic changes post myocardial infarction were classified by hierarchical clustering of 10 gene chips. And then, the differential expressions of 10 selected transcripts identified by the microarray were examined in greater detail by Real Time-PCR. RESULTS: According to hierarchical clustering, we find that the molecular regulatory expression related to cardiac remodeling in the remote zone to myocardial infarction is quite different as time elapses in both diabetic and non-diabetic rats. The gene expression at day 1 and 7 post AMI in both groups is similar, while the genetic changes at day 14 post AMI in diabetic rats and the ones at day 14 and 28 in non-diabetic rats are classified into the same cluster. And then the genetic changes at day 28 and 56 post AMI in diabetic rats and the ones at day 56 in non-diabetic rats are classified into the same cluster. (Figure.1) The patterns of numerous products of genes expression were used in the cluster, including 118 genes, such as leucine-rich PPR-motif containing (IL-6 signaling pathway), procollagen type I, VI, VIII, and XV, fibronectin1, RT1, and TIMP-1, etc. CONCLUSION: The genetic findings in this study might be the possible mechanism that diabetes mellitus can accerate the progression of post-infarction genetic regulatory expression. Experiment Overall Design: All studies were performed with male SD rats (200-220g), aged 8 weeks, which were obtained from laboratorial animal center of Chinese University of Agriculture. DM was induced with a singleintraperitoneal injection of STZ (65 mg/kg in 0.1mmol/L, pH 4.5 sodium citrate buffer) . Age and body weight matched rats that used as non-diabetic controls were injected with the same dose of sodium citrate buffer (0.1mmol/L, pH 4.5). Ultrastructure changes of myocardium were observed 10 weeks after DM induction by TEM. 10 weeks after DM induction,both diabetic and non-diabetic rats were subjected to left anterior descending coronary artery (LADCA) ischemia for 1-56 days without reperfusion. Two-dimensional echocardiography was utilized to obtain LV dimensions and LV percent fractional shortening at baseline, DM 10weeks, and at 1d, 7d, 14d, 28d, 56d after AMI; the remote zone tissues of LV free wall were taken as samples at day 1, 7, 14, 28, and 56 post AMI for gene chip microarray analysis (10 samples from 30 rats); in addition, heart-to-body weight and heart to tibial length ratios and masson's trichrome staining was measured as an index of cardiac hypertrophy and fibrosis at baseline, DM 10weeks, and at 1d, 7d, 14d, 28d, 56d after AMI.
Project description:Identification of genes associated with exposure to the carcinogen Nitrosamine (NNK) in mouse lungs of susceptible and resistant strains. Microarrays were used to capture all of the up and down regulated genes in two strains of mice. Lungs were excised and analyzed between 3-12 weeks after exposure to NNK before mature tumors had formed
Project description:Seven novel and potent Raf small molecule kinase inhibitors were evaluated in 7-day oral repeat-dose rat toxicity studies. All compounds tested induced hyperplasia in multiple tissues. Microarrays were used to investigate transciptional changes associated by treatment with a single compound to gain insight into the cellular changes that may contribute to the tissue hyperplasia. Two groups (25 females/group) received oral daily dosing for 7 days of either Vehicle or compound C1 dosed at 100 mg/kg. Five animals from each group were euthanized on Days 1 (4-5 hrs post first dose; received 1 dose), 2 (received 1 dose), 3 (received 2 doses), 5 (received 4 doses) and 8 (received 7 doses). Bladder tissues were collected and profiled at all five time points. Stomach tissues were collected and profiled at the earliest two time points. A single day 3 animal was not available for genomic profiling; therefore, expression data was collected for a total of 49 bladder and 20 stomach samples.
Project description:Inflammation and oxidative stress have been implicated in the pathogenesis of metabolic disturbances. Esters of fumaric acid, mainly dimethyl fumarate (DMF), exhibit immunomodulatory, anti-inflammatory, and anti-oxidative effects. In the current study, we tested the hypothesis that fumaric acid ester treatment of an animal model of inflammation and metabolic syndrome, the spontaneously hypertensive rat transgenically expressing human C-reactive protein (SHR-CRP), will ameliorate inflammation, oxidative stress, and metabolic disturbances.
Project description:Spermatogonial stem cells (SSCs) provide foundation for spermatogenesis by undergoing continuous self-renewal division. Previous studies have reported conflicting results on the role of the pituitary gland activity in SSC self-renewal. In this study, we analyzed the role of hormonal regulation of SSCs using Lhcgr (luteinizing hormone/choriogonadotropin receptor) knockout mice. Analysis of gene expression profiles showed that testes of Lhcgr-deficient mice exhibit significantly enhanced Wnt5a expression in Sertoli cells. Lhcgr KO and control WT mice were treated with busulfan in order to eliminate germ cells. The total RNA samples from their testes were subjected to microarray analysis to compare their gene expression profiles.
Project description:Furan is a widely used industrial chemical and a common contaminant in heated foods. Chronic furan exposure has been shown to cause cholangiocarcinoma and hepatocellular tumors at doses of 2 mg/kg bw/day with gender differences in frequency and severity. The hepatic transcriptional alterations induced by low doses of furan (doses below those inducing liver tumors) and the potential mechanisms underlying gender differences are largely unexplored. We used DNA microarrays to examine the global hepatic mRNA and microRNA transcriptional profiles of male and female rats exposed to 0, 0.03, 0.12, 0.5 or 2 mg/kg bw/day furan over 90 days. Marked gender differences in gene expression responses to furan were observed, with many more altered genes in exposed males than females, confirming the increased sensitivity of males even at the low doses. Pathway analysis supported that key events in furan-induced hepatotoxicity in males included gene expression changes related to oxidative stress, apoptosis and inflammatory response, while pathway changes in females were consistent with primarily adaptive responses (regeneration). Pathway benchmark doses (BMDs) were estimated and compared to relevant apical endpoints. Transcriptional BMDs could be examined in males, they ranged from 0.08 M-bM-^@M-^S 1.43 mg/kg bw/day and approximated those derived from traditional histopathology. MiR-34a (a target of P53 signalling) was the only microRNA significantly increased at the 2 mg/kg bw/day, providing evidence in support of the importance of apoptosis and cell proliferation in furan hepatotoxicity. Overall, this study demonstrates the use of transcriptional profiling to discern mode of action and mechanisms involved in gender differences. A total of 50 RNA samples (5 female and 5 male rats per dose group, 5 dose groups total) were labelled with Cyanine 5-CTP using Low Input Quick Amp Labelling kits (Agilent Technologies Inc.) following the manufacturerM-bM-^@M-^Ys instruction. Universal rat reference total RNA (Agilent Technologies Inc.) was labelled with Cyanine 3-CTP. Cy5-sample cRNA and Cy3-reference cRNA were hybridized to Agilent G4853A SurePrint G3 Rat GE 8 X 60K microarrays (Agilent Technologies Inc.). One microarray from the male group did not pass the quality control and was eliminated from further analyses
Project description:Wistar Kyoto Rats were administered glucocorticoid pellets and placebo pellets for 6 months. After 6 months rats were sacrificed and their femoral heads were histologically examined for the detection of avascular necrosis of the femoral head. Total RNA was extracted from femoral heads and submitted to gene chip microarray for differential gene expression analysis..
Project description:Lead exposure causes a variety of health effects, especially in children, that may include cognitive and behavioural problems. This study explores the mechanisms associated with this relationship by assessing alterations in gene expression of C57BL/6J pups treated with 50mg/kg lead compared to controls. In addition this study also analyzed brain gene expression differences in Metallothionein I and II (Mt-I and Mt-II) knockout mice treated with lead. Pups of three genotypes (C57BL/6J, Mt-KO with a C57BL/6J background and Heterozygote Mt-KO) were injected with lead acetate during synaptogenesis and weight-matched controls were injected with saline at the same time points. Whole brains were harvested and RNA extracted and pooled from 5 pups and hybridized to Mouse Genome 430 2.0 Arrays. In total 6 arrays were used, one for each genotype and treatment.
Project description:Male F344 rats were expsoed to sub-toxic (50 or 150 mg/kg) or toxic (1500 or 2000 mg/kg) doses of acetaminophen. RNa was extracted from livers and gene expression analysis was performed on Agilent rat oligonucleotide chips. Experiment Overall Design: Individual treated animal RNA was compared to control animal pooled RNA.
Project description:C-peptide exerts beneficial effects on glomerular hyperfiltration in type I diabetic patients. As C-peptide localizes to the nucleus, we investigated the transcriptional activities of C-peptide in proximal tubular cells isolated from diabetic rats. Two groups of proximal tubular cells isolated from type I diabetic rats: 1 treated with C-peptide, and 1 untreated. 2-3 replicates per group.