The primary aim of this study was to evaluate the changes in hepatocyte gene expression under short-term hypoxic conditions in wild type and HIF-1a null cultures. To this end, hypoxia treated cultures were subjected to incubation with 1% O2/5% CO2/94% N2 at 37 C for eight hours prior to RNA isolation. Duplicate normoxic controls were established from separate animals wherein cultures were untreated and treated with Adbgal. Biological triplicates of wild type and HIF-1a null cultures were placed under hypoxic conditions and subsequently processed for microarray analysis. A total of 10 microarray hybridizations were performed.
In vitro liver tissue model established from transgenic mice: role of HIF-1alpha on hypoxic gene expression.
No sample metadata fields
View SamplesInduced pluripotent stem cell-derived human hepatocyte-like cells (iHeps) could provide a powerful tool for studying the mechanisms underlying human liver development and disease, testing the efficacy and safety of pharmaceuticals across different patients (i.e. personalized medicine), and enabling cell-based therapies in the clinic. However, current in vitro protocols that rely upon growth factors and extracellular matrices (ECM) alone yield iHeps with low levels of liver functions relative to adult primary human hepatocytes (PHHs). Moreover, these low hepatic functions in iHeps are difficult to maintain for prolonged times (weeks to months) in culture. Here, we engineered a micropatterned co-culture (iMPCC) platform in a multi-well format that, in contrast to conventional confluent cultures, significantly enhanced the functional maturation and longevity of iHeps in culture for 4 weeks in vitro when benchmarked against multiple donors of PHHs. In particular, iHeps were micropatterned onto collagen-coated domains of empirically optimized dimensions, surrounded by 3T3-J2 murine embryonic fibroblasts, and then sandwiched with a thin layer of ECM gel (Matrigel). We assessed iHep maturity via global gene expression profiles, hepatic polarity, secretion of albumin and urea, basal CYP450 activities, phase-II conjugation, drug-mediated CYP450 induction, and drug-induced hepatotoxicity. Conclusion: Controlling both homotypic interactions between iHeps and heterotypic interactions with stromal fibroblasts significantly matures iHep functions and maintains them for several weeks in culture. In the future, iMPCCs could prove useful for drug screening, studying molecular mechanisms underlying iHep differentiation, modeling liver diseases, and integration into human-on-a-chip systems being designed to assess multi-organ responses to compounds.
Enhancing the functional maturity of induced pluripotent stem cell-derived human hepatocytes by controlled presentation of cell-cell interactions in vitro.
Specimen part, Subject
View SamplesWe report the correlation between lung-derived neonatal MSCs and 2 clinical variables among preterm newborns: corrected gestational age (CGA) at collection and the severity of bronchopulmonary dysplasia (BPD) Overall design: To test the correlation between the transcriptional profiles of tracheal aspirate-derived mesenchymal stromal cells with late stage lung development and with bronchopulmonary dysplasia.
Lung-Resident Mesenchymal Stromal Cells Reveal Transcriptional Dynamics of Lung Development in Preterm Infants.
Specimen part, Subject
View SamplesThe fragile X mental retardation protein FMRP is an RNA binding protein that regulates translation of its bound mRNAs through incompletely defined mechanisms. FMRP has been linked to the microRNA pathway and we show here that it is associated with MOV10, a putative helicase that is also associated with the microRNA pathway. We show that FMRP associates with MOV10 in an RNA-dependent manner and facilitates MOV10-association with RNAs in brain. We identified the RNA sequences recognized by MOV10 using iCLIP and found an increased number of G-quadruplexes in the CLIP sites. We provide evidence that MOV10 facilitates microRNA-mediated translation regulation and also has the novel role of increasing the expression of a subset of RNAs by sterically hindering Argonaute2 association. In summary, we have identified a new mechanism for FMRP-mediated translational regulation through its association with MOV10. Overall design: Comparison of MOV10 siRNA knockdown, irrelevant siRNA control and MOV10 overexpression on total RNA levels
MOV10 and FMRP regulate AGO2 association with microRNA recognition elements.
Specimen part, Cell line, Treatment, Subject
View SamplesUsing the iCLIP protocol we have identified the cellular RNA entities that are bound by MOV10. We report the location and sequence of the MOV10 binding region on each RNA entity. Overall design: To identify the RNAs that bound MOV10, we UV-cross-linked HEK293F cells and immunoprecipitated with an irrelevant antibody (ir or "control") followed by a MOV10-specific antibody (MOV10) to isolate associated RNAs after stringent washing.
MOV10 and FMRP regulate AGO2 association with microRNA recognition elements.
No sample metadata fields
View SamplesPrimary human hepatocytes (PHHs) are a liver-specific cell subtype, and we have shown that these cells respond in a unique manner to the introduction of hepatitis C viral RNA (HCV vRNA) derived from different genotypes of the virus.
Transmitted/founder hepatitis C viruses induce cell-type- and genotype-specific differences in innate signaling within the liver.
Specimen part
View SamplesRecent genetic studies in mice have established a key role for the nuclear receptor coregulator Trim24 in liver tumor suppression and provided evidence that Trim24 suppresses hepatocarcinogenesis by inhibiting retinoic acid receptor alpha (Rara)-dependent transcription and cell proliferation. However, it is unknown which downstream targets of Rara regulated by Trim24 are critical for tumorigenesis. We report here that loss of Trim24 results in the overexpression of interferon (IFN)/STAT pathway genes in the liver, a process that occurs early in tumorigenesis and is more pronounced in tumors, despite the enhanced expression, late in the disease, of negative regulators such as Usp18, Socs1 and Socs2.
Tripartite motif 24 (Trim24/Tif1α) tumor suppressor protein is a novel negative regulator of interferon (IFN)/signal transducers and activators of transcription (STAT) signaling pathway acting through retinoic acid receptor α (Rarα) inhibition.
Specimen part
View SamplesDeployment of a cell-specifying enhancer repertoire by the pioneer factor Pax7 The establishment and maintenance of cell identity depends on implementation of stable cell-specific chromatin landscapes. Pioneer transcription factors establish new cell fate competences by triggering chromatin remodeling during development. Here, we used pituitary cell specification to define the salient features of pioneer action. Comparison of purified pituitary cells of different lineages showed that chromatin accessibility differs at enhancers rather than promoters. The pioneer factor Pax7 specifies one pituitary lineage identity by opening a specific repertoire of enhancers that are distinct from the myogenic targets of Pax7. Pax7 binds its pioneer targets rapidly and days before chromatin remodeling and gene activation. Finally, enhancers opened by Pax7-dependent chromatin remodeling exhibit loss of DNA methylation and they acquire long term epigenetic memory. The present work identifies enhancer pioneering as a critical feature for cell fate specification and maintenance. Overall design: RNA extraction followed by high throughput sequencing (RNA-seq)
Pioneer factor Pax7 deploys a stable enhancer repertoire for specification of cell fate.
Specimen part, Cell line, Treatment, Subject
View SamplesThe transcriptional coregulator Trim24 (formerly known as TIF1a) functions in mice as a liver-specific tumor suppressor. Mice carrying a null mutation in the Trim24 gene all develop hepatocellular carcinoma (HCC).
Loss of Trim24 (Tif1alpha) gene function confers oncogenic activity to retinoic acid receptor alpha.
Age
View SamplesAnalysis of lung CD11c+ antigen presenting cells (APCs) isolated from wildtype or Mir22-/- mice exposed to nanoparticulate carbon black (nCB) for one month. MiR-22 plays important roles in nCB induced experimental emphysema through regulating APC activation. Results provide insight into the biological role and target genes of miR-22.
The microRNA miR-22 inhibits the histone deacetylase HDAC4 to promote T(H)17 cell-dependent emphysema.
Age, Specimen part
View Samples