Project description:Approaches for discovering mechanisms of action and for identifying molecular biomarkers in biomedical research are evolving today, as the growing symbiosis with computational sciences becomes more widely appreciated than ever. In fact, the combination of various new technologies has been pushing forward both frontiers. Here, we present an example of the combined use of in vivo siRNA knock-down technology, genome-wide gene expression profiling, and computational reasoning to unveil regulatory causal relationships and the sufficiency network of identified genes for compound-induced toxicity. Unlike previously reported approaches, our method requires only one targeted perturbation for genome-wide de novo pathway discovery. Hence, our method can be directly applied to animal models in which it is still technically challenging to perform genome-wide genetic perturbation or RNAi screening. The independent application of our derived model to compounds with unrelated mechanisms of action suggests the existence of a universal molecular module that mediates liver hypertrophy. The resulting sufficiency network for induction of liver hypertrophy will have an immediate impact on the progress of toxicogenomics. When combined with phenotypic evaluation, our approach should help to unleash the full potential of siRNAs in systematically unveiling the molecular mechanisms of biological events. Keywords: Regulatory pathway discovery by In vivo transcription modification
Project description:Fenofibrate is a synthetic ligand for the nuclear receptor peroxisome proliferator-activated receptor (PPAR) alpha, but there are reports that fenofibrate affects endothelial cells in PPARa-independent manner. In order to identify PPARa-dependently and PPARa-independently regulated transcripts we generated microarray data from human endothelial cells treated with fenofibrate with and without siRNA-mediated knock-down of PPARa. In this study, we generated microarray data from human umbilical vein endothelial cells (HUVECs) treated with fenofibrate with pretreatment PPARa or control siRNA. There are four time points (4, 8, 12 and 18hours) (n=1 at each time point).
Project description:Fenofibrate is a synthetic ligand for the nuclear receptor peroxisome proliferator-activated receptor (PPAR) alpha, but there are reports that fenofibrate affects endothelial cells in PPARa-independent manner. In order to identify PPARa-dependently and PPARa-independently regulated transcripts we generated microarray data from human endothelial cells treated with fenofibrate with and without siRNA-mediated knock-down of PPARa.
Project description:Fenofibrate is a synthetic ligand for the nuclear receptor peroxisome proliferator-activated receptor (PPAR) alpha, but there are reports that fenofibrate affects endothelial cells in PPARa-independent manner. In order to identify PPARa-dependently and PPARa-independently regulated transcripts we generated microarray data from human endothelial cells treated with fenofibrate with and without siRNA-mediated knock-down of PPARa.
Project description:Fenofibrate is a specific agonist of the nuclear receptor PPARa. To identify the gene expression under the strict dependence of hepatic PPARa activity, we generated a new mouse strain of PPARa-specific deletion in hepatocyte (albumin-Cre+/- Pparaflox/flox or LKO) and we compared them to total Ppara KO (KO), wild-type (WT) and liver WT (albumin-Cre-/- Pparaflox/flox or LWT) mice. We used microarrays to detail the global programme of gene expression in liver of Ppara LKO, LWT, Ppara KO and WT male mice. There are 36 liver samples, each from an individual mouse. The samples are from Ppara liver KO (LKO), Ppara KO (KO), wild-type (WT) and liver WT (LWT) male mice of 14 week-old from the same genetic background (C57Bl/6J) treated with Fenofibrate (100 mg/kg/day) or vehicle (aqueous solution of gum Arabic 3%) by daily gavage for 10 days. n= 4 mice for LKO, LWT and WT genotypes treated with vehicle; n=3 for KO mice treated with vehicle; n=5 mice for LWT, LKO and KO genotypes treated with fenofibrate; n=4 WT mice treated with fenofibrate. All mice were sacrified at ZT14.
Project description:Fenofibrate is a specific agonist of the nuclear receptor PPARa. To identify the gene expression under the strict dependence of hepatic PPARa activity, we generated a new mouse strain of PPARa-specific deletion in hepatocyte (albumin-Cre+/- Pparaflox/flox or LKO) and we compared them to total Ppara KO (KO), wild-type (WT) and liver WT (albumin-Cre-/- Pparaflox/flox or LWT) mice. We used microarrays to detail the global programme of gene expression in liver of Ppara LKO, LWT, Ppara KO and WT male mice.
Project description:Expression data from Ppara (peroxisome proliferator activated receptor alpha) KO mice injected with TFEB specifically in liver. In order to identify the effects of TFEB overexpression together with Ppara absence on the liver transcriptome, we performed Affymetrix Gene-Chip hybridization experiments for the injected mice For the analysis on the injected Ppara-KO mice overexpressing TFEB, total RNA was extracted from the liver of three mice; RNA extracted from the liver of not-injected mice was used as control.
Project description:To clarify mouse PPARA autoinduction and hepatocyte proliferation signaling pathways, genome-wide distribution of PPARA in the liver of PPARA agonist-treated mice compared to Vehicle was analyzed.
Project description:If the function of the nuclear receptor PPARa is well-known during a prolongated fasting, its hepatic biological function during feeding and refeeding conditions still needs to be investigated. Moreover, in vivo data collected so far on PPARa function during fasting were obtained using the total Ppara KO transgenic mouse model. To identify genes whose expression is under the strict dependence of hepatic PPARa activity, we generated a new mouse strain of PPARa-specific deletion in hepatocyte (albumin-Cre+/- Pparaflox/flox or LKO) and we compared them to total Ppara KO (KO), wild-type (WT) and liver WT (albumin-Cre-/- Pparaflox/flox or LWT) mice under three nutritional challenges. We used microarrays to detail the global programme of gene expression in liver of Ppara LKO, LWT, Ppara KO and WT male mice fed ad libitum, fasted for 24 hours and refed. There are 52 liver samples, each from an individual mouse. The samples are from Ppara liver KO (LKO), Ppara KO (KO), wild-type (WT) and liver WT (LWT) male mice of 8 week-old from the same genetic background (C57Bl/6J) fed ad libitum, fasted for 24 hours, fasted for 24 hours and then refed 24 hours more with glucose added in water (200g/l). In fed condition (Fed), n= 3 mice for LKO, LWT genotypes, n= 5 for KO and n= 4 fot WT; in fasting condition (Fas), n=5 for LKO, LWT and WT genotypes and n= 3 for KO; in refeeding condition (Ref), n= 5 for LKO, KO and WT genotypes and n= 4 for LWT. All mice were sacrified at ZT14.
Project description:To clarify the mechanism underlying the proliferation of hepatocytes induced by PPARA agonists, expression profiling in liver of wild type and Ppara-null mice treated with PPARA agonist was investigated.