DLK1/FA-1 (delta-like 1/fetal antigen-1) is a transmembrane protein belonging to Notch/Delta family that acts as a membrane-associated or a soluble protein to regulate regeneration of a number of adult tissues. Here, we examined the role of DLK1/FA-1 in bone biology using osteoblast-specific-Dlk1 over-expressing mice (Col1-Dlk1). Col1-Dlk1 mice displayed growth retardation and significantly reduced total body weight and bone mineral density (BMD). CT-scanning revealed a reduced trabecular and cortical bone volume fraction. Tissue-level histomorphometric analysis demonstrated decreased bone formation rate and enhanced bone resorption in Col1-Dlk1 as compared to WT. At a cellular level, DLK1 markedly reduced the total number of bone marrow (BM)-derived CFU-F, as well as their osteogenic capacity. In a number of in vitro culture systems, DLK1 stimulated osteoclastogenesis indirectly through osteoblast-dependent increased production of pro-inflammatory bone resorbing cytokines (e.g, Il7, Tnfa and Ccl3). We found that ovariectomy (ovx)-induced bone loss was associated with increased production of DLK1 in bone marrow by activated T-cells. However, Dlk1-/- mice were protected from ovx-induced bone loss. Thus, we identified DLK1 as a novel regulator of bone mass that function to inhibit bone formation and to stimulate bone resorption. Increasing DLK1 production by T-cells under estrogen deficiency suggests its possible use as a therapeutic target for preventing postmenopausal bone loss.
DLK1 is a novel regulator of bone mass that mediates estrogen deficiency-induced bone loss in mice.
Specimen part
View SamplesHematopoietic Stem Cells (HSC) are originated during embryonic development from endothelial-like cells located in the ventral side of the dorsal aorta around day E10-12 of murine development. This region is called AGM for Aorta/Gonad/Mesonephros and refers to the tissues around the hemogenic aorta. Cells that emerge from the endothelium and show hematopoietic traits can be distinguished by the expression of the c-kit receptor and finally acquire the CD45 marker.
Hematopoietic stem cell development requires transient Wnt/β-catenin activity.
Specimen part
View SamplesThe molecular chaperons FK506-binding proteins (Fkbps) comprise one of three families of peptidyl prolyl isomerases, which promote the transition between cis- and trans-conformations of peptidyl prolyl bonds. Mouse Fkbp family is composed of at least 15 members, but the functions of the large family in cell proliferation and differentiation remain elusive. During myoblast differentiation, the cells need to exit the cell cycle before fusion and terminal differentiation to form myotubes. The clear distinction between proliferation and differentiation provides an ideal model with which to investigate the roles of Fkbps in these two cell biological events. We found that depletion of FkbpC in mouse myoblasts delayed the exit from the cell cycle and expression of myotube-specific genes, whereas its overexpression caused opposite effects. At a mechanistic level, our study revealed a crucial function of FkbpC in Cdk4 activation during myoblast proliferation. Cdk4 undergoes conformational changes in the HSP90/Cdc37/Cdk4 complex as a prerequisite for activation through binding to CyclinD1 accompanied by phosphorylation. Our results showed that FkbpC depletion released Cdk4 from the HSP90 complex, which increased the Cdk4/CyclinD1 complex in myoblasts and sustained high levels of phosphorylated Cdk4 and Rb during differentiation. These results explain the delayed cell cycle exit and differentiation in the depleted cells. In addition, after synchronizing the cell cycle of myoblasts we found dynamic changes of the amounts of FkbpC and Cdk4 in the HSP90 complex during the G1/S transition. Knockout mice of FkbpC demonstrated delayed muscle regeneration after chemical damage, providing an in vivo evidence for the essential role of FkbpC in muscle differentiation. Collectively, our study uncovered FkbpC's critical function as a novel switch regulating the transition from proliferation to differentiation through controlling one of the central regulators of proliferation, Cdk4. Overall design: mRNA profiles of Fkbp4 knockdown, Fkbp5 knockdown and control C2C12 cells at d0, d3 and d5 were generated by using Illumina HiSeq2500.
Promotion of Myoblast Differentiation by Fkbp5 via Cdk4 Isomerization.
Specimen part, Cell line, Subject, Time
View SamplesGene expression profile between Parp-2-/- and wild-type hematopoietic stem/progenitor cells at basal and to the early response (2.5 hours) to 5 Gy total body irradiation
Parp-2 is required to maintain hematopoiesis following sublethal γ-irradiation in mice.
Specimen part
View SamplesGene expression from MCF7 breast cancer cells at different times of TNFa incubation:pcs2 and 14-3-3 transduced cells
Inhibition of specific NF-κB activity contributes to the tumor suppressor function of 14-3-3σ in breast cancer.
Time
View SamplesCircadian rhythms regulate cell proliferation and differentiation; however, little is known about their roles in myogenic differentiation. Our synchronized differentiation studies demonstrate that myoblast proliferation and subsequent myotube formation by cell fusion occur in circadian manners. We found that one of the core regulators of circadian rhythms Cry2, but not Cry1, is critical for the circadian patterns of these two critical steps in myogenic differentiation. This is achieved through the specific interaction between Cry2 and Bclaf1, which stabilizes mRNAs encoding cyclin D1, a G1/S phase transition regulator, and Tmem176b, a transmembrane regulator for myogenic cell fusion. Myoblasts lacking Cry2 display premature cell cycle exit and form short myotubes due to inefficient cell fusion. Consistently, muscle regeneration is impaired in Cry2-/- mice. Bclaf1 knockdown recapitulated the phenotypes of Cry2 knockdown: early cell cycle exit and inefficient cell fusion. This study uncovers a post-transcriptional regulation of myogenic differentiation by circadian rhythms. Overall design: mRNA profiles of Cry1 knockdown, Cry2 knockdown and control C2C12 cells at d0, d3 and d5 were generated by using Illumina HiSeq2500.
Cry2 Is Critical for Circadian Regulation of Myogenic Differentiation by Bclaf1-Mediated mRNA Stabilization of Cyclin D1 and Tmem176b.
Specimen part, Cell line, Subject
View SamplesChanges in gene expression caused by CREBBP/EP300 bromodomain inhibitors in a CML cell line Overall design: K562 cells were treated with CBP30 and I-CBP112 and changes in gene expression were evaluated by RNA-seq
CREBBP/EP300 bromodomains are critical to sustain the GATA1/MYC regulatory axis in proliferation.
Cell line, Treatment, Subject
View SamplesAntiprolifereative effects of CREBBP/EP300 inhibitors were tested in human leukemia and lymphoma cell lines and the molecular mechanisms responsible for such effects were explored. Overall design: K562 cells were treated with CBP-30 (CREBBP/EP300 bromodomain inhibitor), C646 (CREBBP/EP300 HAT activity inhibitor) and JQ1 (BRD4 inhibitor) and changes in gene expression were evaluated by RNA-seq.
CREBBP/EP300 bromodomains are critical to sustain the GATA1/MYC regulatory axis in proliferation.
No sample metadata fields
View SamplesIntroduction: HGFL-Ron signaling is augmented in human breast cancer and is associated with poor overall prognosis. Here, we investigate the role of HGFL-Ron signaling in murine breast cancer stem cells (BCSC) through characterization of BCSC transcriptomes through RNA-sequencing, focusing on the impact of Ron knockdown through a short hairpin construct. Methods:R7 breas cancer cell lines were drived from mammary tumors in transgenic MMTV_Ron mice. They were sorted based on expression of cell surface markers indicative of lineage negative, CD29hi and CD24+ cells. Bulk R7, sorted cells, and sorted cells treated with shRon were submitted for transcriptomic characterization on the Illumina HiSeq 2500. High quality reads were aligned to the mm9 genome and quantified to generate RPKM. Results: Approximately 30 million reads were aligned to the mouse genome in each sample which corresponded to over 36000 transcripts. Of these, ~16000 were included in analysis. Conclusions: Differential expression analysis indicated that depletion of Ron markely reduces mammosphere formation and self-renewal, and highlighted by the decrease in B-catenin and NFKB pathways. Overall design: Transcriptome profiles of bulk and sorted R7 BCSCs with Ron knockdown through RNA-sequencing.
HGFL-mediated RON signaling supports breast cancer stem cell phenotypes via activation of non-canonical β-catenin signaling.
Specimen part, Cell line, Treatment, Subject
View SamplesPurpose: The goal of this study is to compare the transcriptome profilling (RNA-seq) of inflorescences infected with tobacco ratle virus (TRV) to mock inoculated inflorescences (negative controls), in Arabidopsis plants Methods: Inflorescences of systemically TRV infected or mock-inoculated plants were collected from more than 40 independent Arabidopsis plants, at 14 days post-inoculation (dpi). TRV and mock mRNA profiles were generated by deep sequencing by Illumina HiSeq 2000. The sequence reads that passed quality filters (SOAPnuke) were analysed by Burrows-Wheeler (BWA) followed by ANOVA (ANOVA) and TopHat followed by Cufflinks. Genes and isoforms were quantified by RSEM sofware package. qRT-PCR validation was performed using TaqMan and SYBR Green assays. Results: Here we report a significant repression of DNA methylation genes in inflorescences of Arabidopsis plants infected with Tobacco rattle virus (TRV) that coincides with dynamic changes in methylation at the whole genome level. Arabidopsis mutants deficient in DNA methylation were more resistant to this virus in early colonized tissues but more susceptible at later time points of infection, indicating that DNA methylation was critical to control both proliferation and antiviral defense. We found that TRV interference with DNA methylation leads to changes in the methylation and trancriptional status of transposable elements (TEs), including TEs located in the promoter of disease resistance genes that were significantly repressed in plants exposed to TRV. Activation of both TEs and their nearby disease resistance genes was altered in a range of hypo- and hyper-methylated Arabidopsis mutants, indicating that perturbations in DNA methylation contributes to modulate their expression in infected plants. Conclussion: Our study showed that TRV interferes with DNA methylation to alter the transcriptional silencing of TEs, which in turn compromises the expression of neighboring disease resistance genes. Overall design: TRV and mock mRNA profiles were generated from Arabidopsis inflorescences by deep sequencing with Illumina HiSeq 2000.
Crosstalk between epigenetic silencing and infection by tobacco rattle virus in Arabidopsis.
Specimen part, Subject
View Samples