Project description:The study was performed using primary rat hepatocyte in culture from 4 adult male Sprague-Dawley rats to investigate the changes in gene expression under low dose (4μM) and short exposure (3hrs) of cadmium chloride. By comparing the gene expression profiles of control and cadmium-treated cells, the most dramatic and significant changes were for those genes associated with transcriptional regulation, antioxidant response and control of protein integrity. Changes in other genes involved in cellular physiological responses such as inflammation, growth and apoptosis were also observed. Results were further confirmed by quantitative real time polymerase chain reaction (qRT-PCR). Keywords: early protective responses
Project description:The study was performed using primary rat hepatocyte in culture from 4 adult male Sprague-Dawley rats to investigate the changes in gene expression under low dose (4μM) and short exposure (3hrs) of cadmium chloride. By comparing the gene expression profiles of control and cadmium-treated cells, the most dramatic and significant changes were for those genes associated with transcriptional regulation, antioxidant response and control of protein integrity. Changes in other genes involved in cellular physiological responses such as inflammation, growth and apoptosis were also observed. Results were further confirmed by quantitative real time polymerase chain reaction (qRT-PCR). Experiment Overall Design: Primary hepatocytes from four rats were isolated using the collagenase-hyaluronidase perfusion and digestion method. The cells of greater than 85% viability were used in this study. The cells were plated at 90% confluency on culture dishes coated with collagen and maintained in Waymouth's medium containing BSA for 4hrs prior to an overnight incubation with BSA free Waymouth's medium. Control samples and cadmium-treated samples from individual rats were hybridized to RAE 230A arrays (n=4 and 8 microarrays); data were generated and analyzed.
Project description:The molecular basis of TNF tolerance is poorly understood. In this experiment, primary human monocytes were used to examine TNF refractoriness. We detect absolute tolerance as selective, dose-dependently affecting a small group of powerful effector molecules; induction tolerance represented a more general phenomenon. Primary human monocytes were incubated for 48 h with Medium or different TNF-doses and subsequently short-term stimulated for two hours with TNF. Total RNA was prepared and analysed by use of Agilent microarrays. 6 different conditions were analyzed in total, corresponding to cells that were: 1) medium incubated (M+M), 2) medium incubated and short time TNF (400 U/ml) incubated (M+T), 3) low dose TNF (40 U/ml) preincubated (40+M), 4) low dose TNF preincubated and short time TNF incubated (40+T), 5) high dose TNF (400 U/ml) preincubated (400+M), 6) high dose TNF preincubated and short time TNF incubated (400+T). 3 biological replicates (corresponding to three different healthy donors) were analyzed regarding high-dose tolerance conditions (preincubation with 400 U TNF/ml), one of which was analyzed in duplicates (including cell culture, RNA preparation and a dye-swap microarray approach). 2 biological replicates (corresponding to two different healthy donors) were analyzed under low-dose tolerance conditions (preincubation with 40 U/ml). The different human donors were numbered and indicated in brackets (d1-d5).
Project description:Gene expression profiling was performed in each of hepatocyte fraction and non-parenchymal cell fraction enriched with activated hepatic stellate cells/myofibroblasts from cirrhotic rat livers induced by repeated, low-dose diethylnitrosamine (DEN) treatment.
Project description:Environmental cadmium, with a high average dietary intake, is a severe public health risk. However, the long-term health implications of environmental exposure to cadmium in different life stages remain unclear. We used microarrays to explore the effects of early exposure to low-dose cadmium on hepatic gene expression.
Project description:This is a study to explore the transcriptional changes after cadmium treatment in adult rat testes at three time points (control--0 hour, 8 hour and 4 day). Cadmium is an environmental toxicant that is known to affect the male reproductive system. It disrupts the blood-testis barrier irreversibly, and affects the Sertoli-germ cells adhesion, causing germ cell depletion from the seminiferous epithelium. Keywords: Cadmium effect in rat testes
Project description:The biological effects of the pesticide and complex I inhibitor tebufenpyrad (TEBU) on liver cells were investigated by proteomic approaches. Cellular contents and culture media were analyzed in dose-response experiments on primary rat hepatocytes (PRHs).
Project description:In both the regulatory and commercial arenas, the goal is to move away from time consuming, costly in-life rodent studies and towards safety assessment strategies that rely on testing species-relevant cells in vitro. The liver has been a major focus of these efforts, yet there are currently no in vitro alternatives for hepatotoxicity testing accepted by regulators, and the assays that do exist typically utilize hepatocyte monolayer culture. While hepatocytes have been the primary component of in vitro hepatotoxicity assay development, the non-parenchymal cells (NPCs) (i.e., hepatic stellate cells, Kupffer cells, and liver sinusoidal endothelial cells) also play a critical role in the progression of liver pathologies. The goal of this study was to develop an organotypic co-culture system that could read out the various mechanisms of action observed in vivo, as well as maintain metabolic capability and extended viability to allow for repeat dosing. We developed a two-dimensional 96-well plate-based co-culture system that includes primary rat hepatocytes, stellate, Kupffer, and endothelial cells that supports hepatocyte viability and phenotype stability for up to eight days. Importantly, markers of hepatocyte differentiation and polarity are maintained in co-culture, but hepatocyte monocultures with no other cell types lose phenotypic markers after prolonged culture. This co-culture model was leveraged to assess the effects of known hepatotoxic stimuli, and the co-culture model resulted in responses that were more representative of the in vivo phenotypes.
Project description:This is a study to explore the transcriptional changes after cadmium treatment in adult rat testes at three time points (control--0 hour, 8 hour and 4 day). Cadmium is an environmental toxicant that is known to affect the male reproductive system. It disrupts the blood-testis barrier irreversibly, and affects the Sertoli-germ cells adhesion, causing germ cell depletion from the seminiferous epithelium. Experiment Overall Design: Adult Sprague-Dawley rats treated with a single dose of cadmium chloride at 3 mg/kg b.w. by i.p. and terminated after 8 hours (n=2) and 20 hours (n=2). Testes from cadmium-treated rats and untreated (control, 0 hour, n=3) rats were harvested and total RNA were prepared. Standard Affymetrix genechip procedures were followed for the subsequent experiments. Data were analysed in MAS 5.0 and GeneSpring 7.2.
Project description:Time and dose related expression profiles of rat right heart tissue in microsphere bead model for Pulmonary embolism Experiment Overall Design: Rat right tissues of the Vehicle(no beads- control), low dose and high dose from rat bead model for Pulmonary Embolism were collected after 2, 6 and 18 hour time points. The extracted RNA was hybridized to Affymetrix Rat 230-2.0 microarrays to look for the dose and/or time related transcriptional changes associated with experimental Pulmonary Embolism.