Neurons deficient in both GSK-3 alpha and beta isoforms fail to migrate properly and develop abnormal morphology. In exploring mechanisms, we found no change in Wnt transcriptional target genes.
GSK-3 signaling in developing cortical neurons is essential for radial migration and dendritic orientation.
Specimen partView Samples
Radial progenitors deficient in both Mek1 and Mek2 fail to transition to the gliogenic mode in late embryogenesis, and astrocyte and oligodendroglial precursors fail to appear. In exploring mechanisms, we found the Ets transcription family member Etv5/Erm is strongly regulated by MEK. Our microarray assay showed that Erm is specifically downregulated in Mek mutant brain.
MEK Is a Key Regulator of Gliogenesis in the Developing Brain.
Specimen partView Samples
Inactivation of ERK/MAPK signaling in developing postmitotic cortical excitatory neurons results in a significent loss of Ctip2 positive layer 5 neurons and axon projections. Microarray dada revealed the reduced levels of a vast majority of layer V specific transcripts.
Layer specific and general requirements for ERK/MAPK signaling in the developing neocortex.
Specimen partView Samples
Xenoestrogens are part of a group of agents termed endocrine disruptors because of their capacity to perturb normal hormonal actions. It has been suggested that xenoestrogens may contribute to the development of hormone-dependent cancers, such as breast and endometrial cancers. Bisphenol A (BPA) is polymerized to manufacture polycarbonate plastic and epoxy resins. Human exposure occurs when BPA leaches from plastic-lined food and beverage cans. In the present work we are aiming to determine if BPA has carcinogenic properties by using an in vitro system. For this purpose, the human breast epithelial cells MCF-10F were treated with 10-3M to 10-9M BPA continuously for two weeks. The MCF-10F cells treated with 10-3M and 10-4M BPA died, indicating that these concentrations were toxic for the human breast epithelial cells. The cells treated with 10-5M to 10-9M BPA were evaluated for formation of solid masses in collagen and invasion capacity, both phenotypes that are indicators of cell transformation. MCF-10F treated with 10-5M, 10-6M, 10-7M, 10-8M and 10-9M BPA formed a high percentage of solid masses (34.6%, 20%, 42.4%, 31.8% and 32.2%, respectively). Ten passages after BPA treatments, the invasive capacities of the cells were evaluated using Boyden chambers. The invasion capacity was lower in the cells treated at high concentrations of BPA (10-5M and 10-6M), and there was an increased invasion for the cells treated at low BPA concentration (10-9M), although in all the cases the differences were not significant to the controls. Expression and DNA methylation analysis were performed with the cells treated with 10-5M and 10-6M BPA. We found that these cells showed an increased expression of BRCA1, BARD1, CtIP, RAD51 and BRCC3, all genes involved in DNA repair, and downregulation of PDCD5 and BCL2L11 (also known as BIM), both involved in apoptosis. The upregulation of CtIP was related to hypomethylation of the promoter/exon1 of this gene. Furthermore, BPA induced silencing of BCL2L11 by hypermethylation. This is the first demonstration that BPA induces neoplastic transformation of breast epithelial cells and that aberrant DNA methylation of genes involved in DNA repair and apoptosis could be involved in the initiation of the neoplastic process.
Expression and DNA methylation changes in human breast epithelial cells after bisphenol A exposure.
Cell line, TreatmentView Samples
miR-132 and miR-212 are structurally-related microRNAs that have been found to exert powerful modulatory effects within the central nervous system (CNS). Notably, these microRNAs are tandomly processed from the same non-coding transcript, and share a common seed sequence: thus it has been difficult to assess the distinct contribution of each microRNA to gene expression within the CNS. Here, we employed a combination of conditional knockout and transgenic mouse models to examine the contribution of the miR-132/212 gene locus to learning and memory, and then to assess the distinct effects that each microRNA has on hippocampal gene expression. Using a conditional deletion approach, we show that miR-132/212 double knockout mice exhibit significant cognitive deficits in spatial memory, recognition memory, and in tests of novel object recognition. Next, we utilized transgenic miR-132 and miR-212 overexpression mouse lines and the miR-132/212 double knockout line explore the distinct effects of these two miRNAs on the transcriptional profile of the hippocampus. Illumina sequencing revealed that miR-132/212 deletion increased the expression of 1,138 genes; Venn analysis showed that 96 of these genes were also downregulated in mice overexpressing miR-132. Of the 58 genes that were decreased in animals overexpressing miR-212, only four of them were also increased in the knockout line. Functional gene ontology analysis of downregulated genes revealed significant enrichment of genes related to synaptic transmission, neuronal proliferation, and morphogenesis, processes known for their roles in learning, and memory formation. These data, coupled with previous studies, firmly establish a role for the miR-132/212 gene locus as a key regulator of cognitive capacity. Further, although miR-132 and miR-212 share a seed sequence, these data indicate that these miRNAs do not exhibit strongly overlapping mRNA targeting profiles, thus indicating that, these two genes may function in a complex, non-redundant manner to shape the transcriptional profile of the CNS. The dysregulation of miR-132/212 expression could contribute to signaling mechanisms that are involved in an array of cognitive disorders Overall design: Hippocampal mRNA was isolated from CaMKII-Cre::miR-132/212f/f, tTA::miR132, and tTA::miR212 animals, as well as their respective nontransgenic controls. cDNA from six animals was pooled into three independent biological replicates for each. Libraries were prepared according to the Illumina TruSeqTM Sample Preparation Guide and sequenced using an Illumina Genome Analyzer II. Sequences were aligned to the UCSC mm9 reference genome using Bowtie v0.12.7 and custom R scripts. The sequence data have been submitted to the NCBI Short Read Archive with accession number in progress. Relative abundance was measured in Fragments Per Kilobase of exon per Million fragments mapped using Cufflinks v1.2.
Targeted deletion of miR-132/-212 impairs memory and alters the hippocampal transcriptome.
Cell line, SubjectView Samples
Facioscapulohumeral dystrophy (FSHD) is one of the most common inherited muscular dystrophies. The causative gene remains controversial and the mechanism of pathophysiology unknown. Here we identify genes associated with germline and early stem cell development as targets of the DUX4 transcription factor, a leading candidate gene for FSHD. The genes regulated by DUX4 are reliably detected in FSHD muscle but not in controls, providing direct support for the model that misexpression of DUX4 is a causal factor for FSHD. Additionally, we show that DUX4 binds and activates LTR elements from a class of MaLR endogenous primate retrotransposons and suppresses the innate immune response to viral infection, at least in part through the activation of DEFB103, a human defensin that can inhibit muscle differentiation. These findings suggest specific mechanisms of FSHD pathology and identify candidate biomarkers for disease diagnosis and progression.
DUX4 activates germline genes, retroelements, and immune mediators: implications for facioscapulohumeral dystrophy.
Specimen partView Samples
Background: Strategies to improve long term renal allograft survival have been directed to recipient dependent mechanisms of renal allograft injury. In contrast, no such efforts have been made to optimize organ quality in the donor. In order to get insight into the deleterious gene pathways expressed at different time points during deceased kidney transplantation, transcriptomics was performed on kidney biopsies from a large cohort of deceased kidney transplants.
Hypoxia and Complement-and-Coagulation Pathways in the Deceased Organ Donor as the Major Target for Intervention to Improve Renal Allograft Outcome.
Specimen partView Samples
The role of estrogen and testosterone in the regulation of gene expression in the proximal reproductive tract is not completely understood. To address this question, mice were treated with testosterone or estradiol and RNA from the efferent ducts and caput epididymis was processed and hybridized to Affymetrix MOE 430 2.0 microarrays. Analysis of array output identified probe sets in each tissue with altered levels in hormone treated versus control animals. Hormone treatment efficacy was confirmed by determination of serum hormone levels pre- and post-treatment and observed changes in transcript levels of previously reported hormone-responsive genes. Tissue-specific hormone sensitivity was observed with 2867 and 3197 probe sets changing significantly in the efferent ducts after estrogen and testosterone treatment, respectively. In the caput epididymis, 117 and 268 probe sets changed after estrogen and testosterone treatment, respectively, demonstrating a greater response to hormone in the efferent ducts than the caput epididymis. Transcripts sharing similar profiles in the intact and hormone-treated animals compared with castrated controls were also identified. Ontological analysis of probe sets revealed a significant number of hormone-regulated transcripts encode proteins associated with lipid metabolism, transcription and steroid metabolism in both tissues. Real-time RT-PCR was employed to confirm array data and investigate other potential hormone-responsive regulators of proximal reproductive tract function. The results of this work reveal previously unknown responses to estrogen in the caput epididymis and to testosterone in the efferent ducts as well as tissue specific hormone sensitivity in the proximal reproductive tract.
Regulation of gene expression by estrogen and testosterone in the proximal mouse reproductive tract.
Sex, Specimen part, TreatmentView Samples
Analysis of ALR-deficient cells indicates that ALRs are not required for the IFN response to intracellular DNA. To explore whether AIM2-like receptors activated another innate signaling pathway upon
The AIM2-like Receptors Are Dispensable for the Interferon Response to Intracellular DNA.
Treatment, TimeView Samples