Congenital heart defects (CHDs) occur in 0.51% of live births, yet the underlying genetic etiology remains mostly unknown. Recently, a new source of myocardial cells, namely the second heart field (SHF), was discovered in the splanchnic mesoderm. Abnormal development of the SHF leads to a spectrum of outflow tract defects, such as persistent truncus arteriosus and tetralogy of Fallot. Intracellular Ca2+ signaling is known to be essential formany aspects of heart biology including heart development, but its role in the SHF is uncertain. Here, we analyzed mice deficient for genes encoding inositol 1,4,5-trisphosphate receptors (IP3Rs), which are intracellular Ca2+ release channels on the endo/sarcoplasmic reticulum that mediate Ca2+ mobilization. Mouse embryos that are double mutant for IP3R type 1 and type 3 (IP3R1/IP3R3/) show hypoplasia of the outflow tract and the right ventricle, reduced expression of specific molecular markers and enhanced apoptosis ofmesodermal cells in the SHF. Gene expression analyses suggest that IP3R-mediated Ca2+ signalingmay involve, at least in part, theMef2CSmyd1 pathway, a transcriptional cascade essential for the SHF. These data reveal that IP3R type 1 and type 3 may play a redundant role in the development of the SHF.
Inositol 1,4,5-trisphosphate receptors are essential for the development of the second heart field.
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View SamplesT cells contribute to host-tumor interactions in patients with monoclonal gammopathies. Expansions of CD8+CD57+TCRV+ restricted cytotoxic T cell (CTL) clones are found in 48% of patients with multiple myeloma and confer a favorable prognosis. We now report the presence of CTL clones with varying TCRV repertoire in 70% of patients with Waldenstroms Macroglobulinaemia (WM) (n=20). Previous nucleoside analogue (NA) therapy, associated with an increased incidence of transformation to aggressive lymphoma, significantly influenced the presence of TCRV expansions (X2=11.6; P<0.001) as 83% of patients without (n=6) and only 7% with TCRV expansions (n=14) had received NA. Clonality of CD3+CD8+CD57+TCRV+ restricted CTLs were confirmed by TCRV CDR3 size analysis and direct sequencing. To characterize CTL clones, samples of CD3+CD8+CD57+TCRV+ cells were profiled using DNA microarrays and the results were validated on both gene and protein level. By gene set enrichment analysis, CTL clones not only expressed genes (GZMB, PRF1, FGFBP2) from cytotoxic pathways but also genes which suppress apoptosis, inhibit proliferation, arrest cell cycle G1/S transition and activate T cells (RAS, CSK and TOB pathways). Proliferation tracking confirmed their anergic state. Our studies demonstrate the incidence, NA sensitivity and anergic nature of clonal T cells in a B cell tumor.
Clonal expansions of cytotoxic T cells exist in the blood of patients with Waldenstrom macroglobulinemia but exhibit anergic properties and are eliminated by nucleoside analogue therapy.
Specimen part
View SamplesFK1706 potentiated nerve growth factor-induced neurite outgrowth, putatively mediated via FKBP-52 and the Ras/Raf/MAPK signaling pathway. It also improved mechanical allodynia accompanied by the recovery of intraepidermal nerve fiber density in a painful diabetic neuropathy in rats.
FK1706, a novel non-immunosuppressive immunophilin ligand, modifies gene expression in the dorsal root ganglia during painful diabetic neuropathy.
Specimen part, Treatment
View SamplesOct3/4, Sox2, Klf4, and c-Myc re-wire somatic cells to achieve induced pluripotency (iPS cells). However, subtle differences in reprogramming methodology may confound comparative studies of reprogramming-induced gene expression changes. We specifically focused on the design of polycistronic reprogramming constructs, which encode all four factors linked with 2A peptides. Notably, publically available cassettes were found to employ one of two Klf4 variants (Klf4S and Klf4L; GenBank Accession Nos: AAC52939.1 and AAC04892.1), differing only by nine N-terminal amino acids. In a polycistronic context, these two variants generated dissimilar protein stoichiometry, where Klf4L vectors produced more Klf4 protein than those encoding Klf4S.
KLF4 N-terminal variance modulates induced reprogramming to pluripotency.
Sex, Specimen part
View SamplesThere is a gradient of -catenin expression along the colonic crypt axis with the highest levels at the crypt bottom. However, it remains unclear whether different levels of canonical Wnt signaling exert distinct roles in the colonic epithelium. In the present study, we first showed that the canonical Wnt signaling is active in the proliferative compartment of normal colonic crypts by separating actively proliferating progenitor cells from non-proliferating cells in the colon using transgenic mice expressing a histone H2B-green fluorescent protein (GFP) fusion protein under the control of a tetracycline responsive regulatory element. Subsequently, we investigated the dose-dependent effect of canonical Wnt activation on colonic epithelial differentiation by controlling the expression levels of stabilized -catenin using a doxycycline-inducible transgenic system in mice. We show that elevated levels of Wnt signaling induce the amplification of Lgr5+ cells, which is accompanied by crypt fission and a reduction in cell proliferation among progenitor cells. In contrast, lower levels of -catenin induction enhanced cell proliferation rates of epithelial progenitors without affecting crypt fission rates. Notably, slow-cycling cells produced by -catenin activation exhibit activation of Notch signaling and the treatment of -catenin expressing mice with a Notch inhibitor turned such slow-cycling cells into actively proliferating cells. Our results indicate that the activation of the canonical Wnt signaling pathway is sufficient for de novo crypt formation, and suggest that different levels of canonical Wnt activations, in cooperation with Notch signaling, establish a hierarchy of slower-cycling stem cells and faster-cycling progenitor cells characteristic for the colonic epithelium.
Dose-dependent roles for canonical Wnt signalling in de novo crypt formation and cell cycle properties of the colonic epithelium.
Sex, Specimen part
View SamplesPatients who cleared HCV viremia early during therapy tended to show favorable outcomes, whereas patients who needed a longer period to clear HCV had poorer outcomes. We explored the mechanisms of treatment resistance by comparing hepatic gene expression before and during treatment
Differential interferon signaling in liver lobule and portal area cells under treatment for chronic hepatitis C.
Specimen part, Time
View SamplesWe report that Zic family (Zic1/2/3) and orphan nuclear receptors family (Esrrb and Nr5a2) transcription factors (TFs) synergistically enhance the reprogramming efficiency when transduced with Oct4, Sox2 and Klf4 (OSK) into murine fibroblasts. To identify the molecular mechanisms underlying this synergy, we analyzed global gene expression at 6 days after introduction of reprogramming factors. As a result, we found that primary targets of these TFs are different when either of TFs was introduced with OSK, but a significant portion of genes including pluripotency makers such as Dppa2 was synergistically upregulated. Further analysis revealed that metabolic pathways are the important targets of these TFs for efficient reprogramming.
Hybrid Cellular Metabolism Coordinated by Zic3 and Esrrb Synergistically Enhances Induction of Naive Pluripotency.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
LEAFY target genes reveal floral regulatory logic, cis motifs, and a link to biotic stimulus response.
Specimen part
View SamplesThe transition from vegetative growth to flower formation is critical for the survival of flowering plants. The plant-specific transcription factor LEAFY (LFY) has central, evolutionarily conserved roles in this process, both in the formation of the first flower and later in floral patterning. We performed genome-wide binding and expression studies to elucidate the molecular mechanisms by which LFY executes these roles. Our study reveals that LFY directs an intricate regulatory network in control of floral homeotic gene expression and, unexpectedly, controls the expression of genes regulating the response to external stimuli in Arabidopsis. We further show that LFY dampens responses to a bacterial MAMP (microbe-associated molecular pattern) and to pathogen challenge. Our findings suggest a molecular mechanism for the coordination of reproductive stage development and disease response programs in plants. Regulation of these distinct survival programs by a single transcription factor may ensure optimal allocation of plant resources for reproductive fitness.
LEAFY target genes reveal floral regulatory logic, cis motifs, and a link to biotic stimulus response.
Specimen part
View SamplesDuring embryogenesis, many key transcription factors are used repeatedly, achieving different outcomes depending on cell type and developmental stage. The epigenetic modification of the genome functions as a memory of a cells developmental history, and it has been proposed that such modification shapes the cellular response to transcription factors. To investigate the role of DNA methylation in the response to transcription factor Gata4, we examined expression profiles of Dnmt3a-/-Dnmt3b-/- ES cell-derived mesoderm cells cultured for 4 days with or without Gata4 activation, as well as the wild-type counterparts, using Affymetrix microarrays.
DNA methylation restricts lineage-specific functions of transcription factor Gata4 during embryonic stem cell differentiation.
Specimen part
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