Receptor tyrosine kinases MET and EGFR are critically involved in initiation of liver regeneration. Other cytokines and signaling molecules also help in the early part of the process. Regeneration employs effective redundancy schemes to compensate for missing signals. Elimination of any single signaling pathway only delays but does not abolish the process. Our present study, however, shows that combined systemic elimination of MET and EGFR signaling abolishes liver regeneration, prevents restoration of liver mass and leads to liver decompensation. Our results demonstrate that liver function is dependent on synchronous availability of signaling from these two pathways. The study shows that MET and EGFR separately control many non-overlapping signaling endpoints, allowing for compensation when only one of the signals is blocked. The combined elimination of the signals however was not tolerated. The results provide critical new information on interactive MET and EGFR signaling and the contribution of their combined absence to regeneration arrest and liver decompensation.
Combined systemic elimination of MET and epidermal growth factor receptor signaling completely abolishes liver regeneration and leads to liver decompensation.
Specimen part, Time
View SamplesMET and EGFR receptor tyrosine kinases are crucial for liver regeneration and normal hepatocyte function. Recently we demonstrated that in mice, combined inhibition of these two signaling pathways abolished liver regeneration following hepatectomy, with subsequent hepatic failure and death at 15-18 days post-resection. Morbidity was associated with distinct and specific alterations in important downstream signaling pathways that led to a decrease in hepatocyte volume, reduced proliferation, and shutdown of many essential hepatocyte functions such as fatty acid synthesis, urea cycle, and mitochondrial functions. In the present study we explore the role of MET and EGFR signaling in resting mouse livers that are not subjected to hepatectomy. Mice with combined disruption of MET and EGFR signaling (Delta MET + EGFRi) were noticeably sick by 10 day and died at 12-14 days. Delta MET + EGFRi mice showed decreased liver to body weight ratios, increased apoptosis in non-parenchymal cells, impaired liver metabolic functions, and activation of distinct, downstream signaling pathways related to inflammation, cell death, and survival. Conclusion: The present study demonstrates that in addition to controlling the regenerative response, MET and EGFR synergistically control baseline liver homeostasis in normal mice in such a way that their combined disruption leads to liver failure and death.
Combined Systemic Disruption of MET and Epidermal Growth Factor Receptor Signaling Causes Liver Failure in Normal Mice.
Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Atrial identity is determined by a COUP-TFII regulatory network.
Age, Specimen part
View SamplesAtria and ventricles exhibit distinct molecular profiles that produce structural and functional differences between the two cardiac compartments. However, factors that determine these differences remain largely undefined. Cardiomyocyte-specific COUP- TFII ablation produces ventricularized atria that exhibit ventricle-like action potentials, increased cardiomyocyte size, and development of extensive T-tubules.
Atrial identity is determined by a COUP-TFII regulatory network.
Age, Specimen part
View SamplesCOUP-TFII, a member of the nuclear receptor superfamily plays a critical role in angiogenesis and organogenesis during embryonic development. Our results indicate that COUP-TFII expression is profoundly upregulated in prostate cancer patients and might serves as biomarker for recurrence prediction. Thus we conduct transcriptome comparison of control and COUP-TFII depleted PC3 cells to gain genomic insights on the biological processes that COUP-TFII is involved in prostate cancer cells. Ingenuity Pathway Analysis (IPA) shows that the most prominent altered pathways in the COUP-TFII depleted cells are related to cell growth; cell cycle progression and DNA damage response. Indeed many growth related genes including E2F1, p21, CDC25A, Cyclin A and Cyclin B are changed in COUP-TFII knockdown cells, suggesting that COUP-TFII might be an important regulator for prostate cancer cell growth. Further functional assays from cells and mice genetic studies confirm the hypothesis that COUP-TFII serve as the major regulator to control prostrate cancer growth. Together, results provide insight into the role of COUP-TFII in prostate tumorigenesis.
COUP-TFII inhibits TGF-β-induced growth barrier to promote prostate tumorigenesis.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Deficiency of the microRNA-31-microRNA-720 pathway in the plasma and endothelial progenitor cells from patients with coronary artery disease.
Specimen part, Treatment, Time
View SamplesEarly EPCs (eEPCs) appear at less than 1 week in culture dishes, whereas late EPCs (LEPCs) appear late at 2-4 weeks. Distinct angiogenic properties between these two EPC subpopulations have been disclosed by the angiogenesis assay: late EPCs, but not eEPCs, form vascular networks de novo and are able to incorporate into vascular networks. On the contrary, eEPCs, but not late ones, indirectly augment tubulogenesis even when physically separated by a Transwell membrane, implying the involvement of a cytokine-based paracrine mechanism.
Deficiency of the microRNA-31-microRNA-720 pathway in the plasma and endothelial progenitor cells from patients with coronary artery disease.
Specimen part, Time
View SamplesHigh glucose impairs the angiogenic activities of late endothelial precursor cells (EPC). We found that far infrared (FIR) treatment restored partially the activity of late EPC. However, the mechanisms are unclear. We performed gene expression microarray analysis to assess the expression profiles of high glucose-treated late EPC with or without FIR treatment.
Deficiency of the microRNA-31-microRNA-720 pathway in the plasma and endothelial progenitor cells from patients with coronary artery disease.
Specimen part, Treatment
View SamplesTazarotene-induced gene 1 (TIG1), also named as retinoic acid receptor responder 1 (RARRES1), is a retinoid inducible type II tumor suppressor gene; the TIG1B isoform inhibits growth and invasion of cancer cells. Expression of TIG1B is frequently downregulated in various cancer tissues; however, the expression and activities of the TIG1A isoform has yet to be analyzed. This study investigated the effects of TIG1A and TIG1B isoforms on gene expression profiles of colon cancer cells. TIG1A, TIG1B and control stable clones derived from HCT116 colon cells were established using the GeneSwitch system. TIG1 isoform expression was induced upon 5 micro Molar of mifepristone (MFP) treatment for 24 hr. Biological triplicate samples were prepared and gene expression profiles were determined by microarray using human genome HGU133 plus 2 array (Affymatrix). Upon induction of TIG1A and TIG1B expression for 24 hr, a total of 129 and 55 genes were significantly altered, respectively. Of the genes analyzed, 23 and 6 genes were up- and downregulated, respectively in both TIG1A and TIG1B expressing cells.
G protein-coupled receptor kinase 5 mediates Tazarotene-induced gene 1-induced growth suppression of human colon cancer cells.
Cell line, Time
View SamplesCOUP-TFII plays a critical role in angiogenesis during development. It has also been shown to suppress Notch signaling pathway to confer vein identity. However, the downstream targets and the mechanism mediate COUP-TFII function to regulate these processes remain elusive. To identify the downstream targets and the mechanism by which COUP-TFII regulates agiogenesis and vein specification, we knocked down COUP-TFII in HUVEC cells using COUP-TFII specific siRNA and used microarray analysis to identify downstream targets. Interestingly, we found the expression of many genes in the cell cycle pathway and Notch signaling pathway are significantly altered in the COUP-TFII depleted cells.
COUP-TFII is a major regulator of cell cycle and Notch signaling pathways.
Specimen part
View Samples