The circadian clock generates daily rhythms in mammalian liver processes, such as glucose and lipid homeostasis, xenobiotic metabolism, and regeneration. The mechanisms governing these rhythms are not well understood, particularly the distinct contributions of the cell-autonomous clock and central pacemaker to rhythmic liver physiology. Through microarray expression profiling in MMH-D3 hepatocytes, we identified over 1,000 transcripts that exhibit circadian oscillations, demonstrating that many rhythms can be driven by the cell-autonomous clock and that MMH-D3 is a valid circadian model system. The genes represented by these circadian transcripts displayed both co-phasic and anti-phasic organization within a protein-protein interaction network, suggesting the existence of competition for binding sites or partners by genes of disparate transcriptional phases. Multiple pathways displayed enrichment in MMH-D3 circadian transcripts, including the polyamine synthesis module of the glutathione metabolic pathway. The polyamine synthesis module, which is highly associated with cell proliferation and whose products are required for initiation of liver regeneration, includes enzymes whose transcripts exhibit circadian oscillations, such as ornithine decarboxylase (Odc1) and spermidine synthase (Srm). Metabolic profiling revealed that the enzymatic product of SRM, spermidine, cycles as well. Thus, the cell-autonomous hepatocyte clock can drive a significant amount of transcriptional rhythms and orchestrate physiologically relevant modules such as polyamine synthesis.
Cell-autonomous circadian clock of hepatocytes drives rhythms in transcription and polyamine synthesis.
Specimen part, Cell line
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Activation of MAPK pathways links LMNA mutations to cardiomyopathy in Emery-Dreifuss muscular dystrophy.
No sample metadata fields
View SamplesThe present research is devoted to the identification of gene(s) severely affected by LMNA mutations, leading to striated muscle laminopathies and more specifically the cardiomyopathy. For this purpose, we developped a large-scale gene expression approach on heart and skeletal tissues from Lmna H222P heterozygous Knock-In mouse model.
Activation of MAPK pathways links LMNA mutations to cardiomyopathy in Emery-Dreifuss muscular dystrophy.
No sample metadata fields
View SamplesThe present research is devoted to the identification of gene(s) severely affected by LMNA mutations, leading to striated muscle laminopathies and more specifically the cardiomyopathy. For this purpose, we developped a large-scale gene expression approach on heart and skeletal tissues from Lmna H222P heterozygous Knock-In mouse model.
Activation of MAPK pathways links LMNA mutations to cardiomyopathy in Emery-Dreifuss muscular dystrophy.
No sample metadata fields
View SamplesOBJECTIVE: To characterize the hormonal milieu and adipose gene expression in response to catch-up growth (CUG), a growth pattern associated with obesity and diabetes risk, in a mouse model of low birth weight (LBW). RESEARCH DESIGN AND METHODS: ICR mice were food restricted by 50% from gestational days 12.5-18.5, reducing offspring birth weight by 25%. During the suckling period, dams were either fed ad libitum, permitting CUG in offspring, or food restricted, preventing CUG. Offspring were killed at age 3 weeks, and gonadal fat was removed for RNA extraction, array analysis, RT-PCR, and evaluation of cell size and number. Serum insulin, thyroxine (T4), corticosterone, and adipokines were measured.
Accelerated postnatal growth increases lipogenic gene expression and adipocyte size in low-birth weight mice.
Sex, Age, Specimen part
View Samplesaffy_pop_2011_08 - poplar bent study - genes regulated by PtaZFP2 in absence of mechanical stress - genes regulated by PtaZFP2 after one bending.Species: Populus tremula x Populus alba-- The laboratory previously established a poplar transgenic line overexpressing PtaZFP2 under the control of an estradiol-inducible promoter. - the experiment, conducted on 3-month-old hydroponically-grown poplars, consists in the comparison of WT poplars treated with estradiol and the PtaZFP2-overexpressing line treated with estradiol. We also compared unbent and bent PtaZFP2-overexpressing poplars. The applied strain is quantitatively controlled (Coutand & Moulia, 2000, JExpBot; coutand et al., 2009, Plant Physiology) -
The zinc finger protein PtaZFP2 negatively controls stem growth and gene expression responsiveness to external mechanical loads in poplar.
Treatment
View Samplesaffy_pop_2011_08 - poplar estradiol study - genes regulated by PtaZFP2 in absence of mechanical stress - genes regulated by PtaZFP2 after one bending.Species: Populus tremula x Populus alba-The laboratory previously established a poplar transgenic line overexpressing PtaZFP2 under the control of an estradiol-inducible promoter. - the experiment, conducted on 3-month-old hydroponically-grown poplars, consists in the comparison of WT poplars treated with estradiol and the PtaZFP2-overexpressing line treated with estradiol. We also compared unbent and bent PtaZFP2-overexpressing poplars. The applied strain is quantitatively controlled (Coutand & Moulia, 2000, JExpBot; coutand et al., 2009, Plant Physiology)
The zinc finger protein PtaZFP2 negatively controls stem growth and gene expression responsiveness to external mechanical loads in poplar.
Treatment
View SamplesThe present research is devoted to the identification of gene(s) severely affected by LMNA mutations, leading to striated muscle laminopathies and more specifically the skeletal phenotype of Emery-Freifuss Muscular Dystrophy.
The non-muscle ADF/cofilin-1 controls sarcomeric actin filament integrity and force production in striated muscle laminopathies.
Age, Specimen part
View SamplesIdentification of druggable targets is a prerequisite for developing targeted therapies against Ewing sarcoma. We report the identification of Protein Kinase C Beta (PRKCB) as a protein specifically and highly expressed in Ewing sarcoma as compared to other pediatric cancers. Its transcriptional activation is directly regulated by the EWSR1-FLI1 oncogene. Getting insights in PRKCB activity we show that, together with PRKCA, it is responsible for the phosphorylation of histone H3T6, allowing global maintenance of H3K4 trimethylation on a variety of gene promoters. In the long term, PRKCB RNA interference induces apoptosis in vitro. More importantly, in xenograft mice models, complete impairment of tumor engraftment and even tumor regression were observed upon PRKCB inhibition, highlighting PRKCB as a most valuable therapeutic target. Deciphering PRKCB roles in Ewing sarcoma using expression profiling, we found a strong overlap with genes modulated by EWSR1-FLI1 and an involvement of RPKCB in regulating crucial signaling pathways. Altogether, we show that PRKCB may have two important independent functions and should be considered as highly valuable for understanding Ewing sarcoma biology and as a promising target for new therapeutic approaches in Ewing sarcoma.
Targeting the EWSR1-FLI1 oncogene-induced protein kinase PKC-β abolishes ewing sarcoma growth.
Cell line
View SamplesEnterocytes assemble dietary lipids into chylomicron particles that are taken up by intestinal lacteal vessels and peripheral tissues. Although chylomicrons are known to assemble in part within membrane secretory pathways, the modifications required for efficient vascular uptake are unknown. We report that the transcription factor Pleomorphic adenoma gene-like 2 (PLAGL2) is essential for this aspect of dietary lipid metabolism. PlagL2-/- mice die from post-natal wasting owing to failure of fat absorption. Lipids modified in the absence of PlagL2 exit from enterocytes but fail to enter interstitial lacteal vessels. Dysregulation of enterocyte genes closely linked to intracellular membrane transport identified candidate regulators of critical steps in chylomicron assembly. PlagL2 thus regulates essential and poorly understood aspects of dietary lipid absorption and its deficiency represents an authentic animal model with implications for amelioration of obesity or the metabolic syndrome.
Loss of the PlagL2 transcription factor affects lacteal uptake of chylomicrons.
No sample metadata fields
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