Previous studies have demonstrated that E-proteins induce AID expression in activated B cells. Here we have examined the role of Id3 in germinal center (GC) cells. We found that Id3 expression is high in follicular B-lineage cells but declines in GC cells. Immunized mice depleted for Id3 expression displayed a block in germinal center B cell maturation, showed reduced numbers of marginal zone B cells and class switched cells, were associated with decreased antibody titers and lower numbers of plasma cells. In vitro Id3-depleted B cells displayed a defect in class switch recombination. Whereas AID levels were not altered in Id3-depleted activated B cells, the expression of a subset of genes encoding for signaling components of antigen receptor, cytokine receptor and chemokine receptor mediated signaling was significantly impaired. We propose that during the GC reaction Id3 levels decline to activate the expression of genes encoding for signaling components that mediate B cell receptor and or cytokine-mediated signaling to promote the differentiation of GC B cells. Overall design: B cells derived from control and CD19-Cre;Id3loxP/loxP mice were activated in vitro in the presence of LPS and IL-4 for 24 or 48 hours. RNA was isolated from naïve as well as activated control and CD19-Cre;Id3loxP/loxP mice and analyzed by RNA-seq, in duiplicate.
Id3 Orchestrates Germinal Center B Cell Development.
Specimen part, Cell line, Subject
View SamplesScreening small molecules and drugs for activity to modulate alternative splicing, we found that amiloride, distinct from four other intracellular pH-affecting analogues, could normalize the splicing of BCL-X, HIPK3 and RON/MISTR1 transcripts in human hepatocellular carcinoma Huh-7 cells. To elucidate the underlying mechanisms, our proteomic analyses of amiloride-treated cells detected hypo-phosphorylation of splicing factor SF2/ASF and also decreased levels of SRp20 and two un-identified SR proteins. We further observed decreased phosphorylation of AKT, ERK1/2 and PP1, while increased phosphorylation of p38 and JNK, suggesting that amiloride treatment down-regulated kinases and up-regulated phosphatases in the signal pathways known to affect the splicing factor protein phosphorylation. The amiloride effects of splicing factor protein hypo-phosphorylation andnormalizedoncogenic RNA splicing were both abrogated by pre-treatment with a PP1 inhibitor. We then performed global exon array analysis of Huh-7 cells treated with amiloride for 24 hours. Using gene array chips (Affymetrix GeneChip Human Exon 1.0 ST Array of >518000 exons of 42974 genes) for exon array analysis (set parameters of correlation coefficient 0.7, splicing index -1.585 , and log2 ratio -1.585), we found that amiloride influenced the splicing patterns of 551 genes involving at least 584 exons, which included 495 known protein-coding genes involving 526 exons, many of which play key roles in functional networks of ion transport, extracellular matrix, cytoskeletons and genome maintenance. Cellular functional analyses revealed subsequent invasion and migration defects, cell cycle disruption, cytokinesis impairment, and lethal DNA degradation in amiloride-treated Huh-7 cells. This study thus provides mechanistic underpinnings for exploiting small molecule modulation of abnormal RNA splicing for cancer therapeutics.
Small molecule amiloride modulates oncogenic RNA alternative splicing to devitalize human cancer cells.
Cell line
View SamplesTo elucidate host processes and components required for the sustained growth and reproduction of the obligate biotrophic fungus Golovinomyces orontii on Arabidopsis thaliana, laser microdissection was used to isolate cells at the site of infection at 5 days postinfection for downstream global Arabidopsis expression profiling. Site-specific profiling increased sensitivity dramatically, allowing us to identify specific host processes, process components, and their putative regulators hidden in previous whole-leaf global expression analyses. For example, 67 transcription factors exhibited altered expression at the powdery mildew (PM) infection site, with subsets of these playing known or inferred roles in photosynthesis, cold/dehydration responses, defense, auxin signaling, and the cell cycle. Using integrated informatics analyses, we constructed putative regulatory networks for a subset of these processes and provided strong support for host cell cycle modulation at the PM infection site. Further experimentation revealed induced host endoreduplication occurred exclusively at the infection site and led us to identify MYB3R4 as a transcriptional regulator of this process. Induced endoreduplication was abrogated in myb3r4 mutants, and G. orontii growth and reproduction were reduced. This suggests that, by increasing gene copy number, localized endoreduplication serves as a mechanism to meet the enhanced metabolic demands imposed by the fungus, which acquires all its nutrients from the plant host.
Laser microdissection of Arabidopsis cells at the powdery mildew infection site reveals site-specific processes and regulators.
Age, Specimen part
View SamplesThe tumor suppressor genes EAF2 and p53 are frequently dysregulated in prostate cancers. Recently, we reported that concurrent p53 nuclear staining and EAF2 downregulation were associated with high Gleason score. Combined loss of EAF2 and p53 in a murine model induced prostate tumors, and concurrent knockdown of EAF2 and p53 in prostate cancer cells enhanced proliferation and migration, further suggesting that EAF2 and p53 could functionally interact in the suppression of prostate tumorigenesis. Here, RNA-seq analyses identified differentially regulated genes in response to concurrent knockdown of p53 and EAF2. Several of these genes were associated with the STAT3 signaling pathway, and this was verified by significantly increased p-STAT3 immunostaining in the Eaf2-/-p53-/- mouse prostate. STAT3 knockdown abrogated the stimulation of C4-2 cell proliferation by concurrent knockdown of EAF2 and p53. Furthermore, immunostaining of p-STAT3 was increased in human prostate cancer specimens with EAF2 downregulation and/or p53 nuclear staining. Our findings suggest that simultaneous inactivation of EAF2 and p53 can act to activate STAT3 and drive prostate tumorigenesis. Overall design: C4-2 prostate cancer cells treated with siEAF2 and/or sip53 mRNA profiles were generated by deep sequencing, using Illumina HiSeq 2000.
EAF2 and p53 Co-Regulate STAT3 Activation in Prostate Cancer.
Specimen part, Cell line, Subject
View SamplesWe used RNA-Seq to detail the global program of sexually dimorphic dexamethasone regulated gene expression in embryonic hypothalamic neural progenitor/stem cells. Overall design: RNAseq on Primary E14.5 mouse hyothalamic neurosphere cultures. 4 conditions - Male Dex, Male EtOH, Female Dex and Female EtOH. There are 3 biological replicates for each condition and all the 12 samples are run on two lanes (techinical duplicates).
Research Resource: The Dexamethasone Transcriptome in Hypothalamic Embryonic Neural Stem Cells.
Sex, Cell line, Treatment, Subject
View SamplesThe optimal T cell attributes for the adoptive immunotherapy of cancer and viral diseases are currently unclear. Recent adoptive transfer clinical trials using ex vivo expanded tumor infiltrating lymphocytes has provided evidence that differentiated effector T cells can mediate durable responses in selected cancer patients. The capacity of these transferred cells to persist in the host was found to strongly correlate with their clinical activity. Thus, there is significant interest in identifying intrinsic markers that define antigen specific effector T cells that can develop into long-lived memory cells rather than undergoing apoptosis after infusion in humans. We recently reported the long term persistence of ex vivo expanded tumor specific CD8+ T effector clones in refractory metastatic melanoma patients after adoptive T cell transfer. By utilizing these highly homogeneous clone populations, we sought to define the pre-infusion cellular and molecular attributes associated with their effector to memory transition. Comparative transcriptional profiling found the pre-infusion clone mRNA expression levels of the IL-7 receptor (IL-7Ra) and the proto-oncogene, c-myc, directly correlated with the level of clonal persistence after adoptive transfer in humans. The predictive value of these markers was further established by utilizing IL-7R protein, induced pSTAT5, and c-myc mRNA expression to prospectively identify human tumor specific effector clones that could engraft after controlled adoptive transfer into highly immunodeficient mice. These findings support that IL-7R and c-myc expression are valuable cell intrinsic markers that can predict the fate of effector CD8+ T cells after adoptive transfer.
Tumor-Specific Effector CD8+ T Cells That Can Establish Immunological Memory in Humans after Adoptive Transfer Are Marked by Expression of IL7 Receptor and c-myc.
Specimen part
View SamplesPKA activation by FSH is essential to transduce FSH-mediated effects on granulosa cell proliferation, differentiation and steroidogenesis. However, It is unknown whether activation of PKA is sufficient to account for the entire program of granulosa cell responses to FSH. We addressed this question by conducting a comprehensive comparative analysis of signaling pathways and gene expression profiles of granulosa cells stimulated with FSH or expressing a constitutively active PKA mutant, PKA-CQR.
Protein Kinase A: A Master Kinase of Granulosa Cell Differentiation.
Age, Specimen part, Treatment
View SamplesIn plants, the activation of immunity is often inversely correlated with growth. Mechanisms that plant growth in the context of pathogen challenge and immunity are unclear. Investigating Arabidopsis infection with the powdery mildew fungus, we find that the Arabidopsis atypical E2F DEL1, a transcriptional repressor known to promote cell proliferation, represses accumulation of the hormone salicylic acid (SA), an established regulator of plant immunity. DEL1 deficient plants are more resistant to pathogens and slightly smaller than wild type. The resistance and size phenotypes of DEL1 deficient plants are due to the induction of SA and activation of immunity in the absence of pathogen challenge. Moreover, Enhanced Disease Susceptibility 5 (EDS5), a SA transporter required for elevated SA and immunity, is a direct repressed target of DEL1. Together, these findings indicate that DEL1 control of SA levels contributes to regulating the balance between growth and immunity in developing leaves.
Atypical E2F transcriptional repressor DEL1 acts at the intersection of plant growth and immunity by controlling the hormone salicylic acid.
Age, Specimen part
View SamplesAlternative splicing is a mechanism for increasing the protein variety of a limited number of genes. Studies have shown that aberrant regulations of the alternative splicing of apoptotic gene transcripts may contribute to the development of cancer. In this study, we isolated 4ß-Hydroxywithanolide E (4bHWE) from the traditional herb Physalis peruviana, and analyzed its biological effects in cancer cells. The results demonstrated that 4bHWE modulates the alternative splicing of apoptotic genes (e.g., HIPK3, SMAC/DIABLO, and SURVIVIN), changes the expression level of splicing factors (e.g., hnRNP C1/C2, ASF/SF2, SRp20, and SRp55), and induces histone tail posttranslational modifications (e.g., H3K27me1, H3K27me2, H3K36me3, and H3K79me1). Pretreatment with okadaic acid to inhibit protein phosphatase-1 could partly relieve the effects of 4bHWE on the alternative splicing of HIPK3 and SMAC/DIABLO transcripts, as well as on the dephosphorylation of ASF/SF2. Genome-wide detection of alternative splicing further indicated that several other apoptosis-related genes are also regulated by 4bHWE, including APAF1, CARP-1, and RIPK1. Moreover, we extended our study to apoptosis-associated molecules, detecting an increasing level of CASPASE-3 activity and cleavage of poly ADP-ribose polymerase in 4bHWE-induced apoptosis. Furthermore, in vivo experiments showed that the treatment of tumor-bearing mice with 4bHWE resulted in a marked decrease of tumor size and weight. Taken together, this study is the first to show that 4bHWE affects alternative splicing through the modulations of splicing factors, providing a novel view of the antitumor mechanism of 4bHWE. Overall design: Examination of the global genes with altered alternative splicing in 4bHWE-treated Huh-7 cells.
4β-Hydroxywithanolide E Modulates Alternative Splicing of Apoptotic Genes in Human Hepatocellular Carcinoma Huh-7 Cells.
Specimen part, Treatment, Subject
View SamplesA deletion in the CMAH gene in humans occurred approximately 3.5 million years ago. This resulted in the inactivation of the CMP-Neu5Ac hydroxylase enzyme, and hence, in the specific deficiency in N-glycolylneuraminic acid (Neu5Gc), a form of sialic acid, in all modern humans. Although there is evidence that this molecular milestone in the origin of humans may have led to the evolution of human-specific pathogens, how deficiency in Neu5Gc might alter progression of non-infectious human diseases remains unanswered. Here, we have investigated cardiac and skeletal muscle gene expression changes in mdx mice, a model of Duchenne muscular dystrophy (DMD), that do or do not carry the human-like inactivating mutation in the mouse Cmah gene. We have evidence that Neu5Gc-deficiency in humans might explain some of the discrepancies in the disease phenotype between mdx mice and DMD patients.
A human-specific deletion in mouse Cmah increases disease severity in the mdx model of Duchenne muscular dystrophy.
Sex, Age, Specimen part
View Samples