The 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 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 SamplesAccumulating evidence suggests that mitochondrial dysfunction underlies the pathophysiology of bipolar disorder (BD) and schizophrenia (SZ). We performed large-scale DNA microarray analysis of postmortem brains of patients with BD or SZ, and examined expression patterns of mitochondria-related genes. We found a global down-regulation of mitochondrial genes, such as those encoding respiratory chain components, in BD and SZ samples, even after the effect of sample pH was controlled. However, this was likely due to the effects of medication. Medication-free patients with BD showed tendency of up-regulation of subset of mitochondrial genes. Our findings support the mitochondrial dysfunction hypothesis of BD and SZ pathologies. However, it may be the expression changes of a small fraction of mitochondrial genes rather than the global down-regulation of mitochondrial genes. Our findings warrant further study of the molecular mechanisms underlying mitochondrial dysfunction in BD and SZ.
Altered expression of mitochondria-related genes in postmortem brains of patients with bipolar disorder or schizophrenia, as revealed by large-scale DNA microarray analysis.
No sample metadata fields
View SamplesRecent revelations into microRNA function suggest that microRNAs serve as a key player in a robust adaptive response against stress in animals through their fine-tuning capability in gene expression. However, it remains largely unclear how a microRNA-modulated downstream mechanism contributes to the process of homeostatic adaptation. Here we show that loss of an intestinally expressed microRNA gene mir-60 in the nematode C. elegans promotes adaptive response against oxidative stress; animals lacking mir-60 dramatically extend lifespan under a mild and long-term oxidative stress condition, while they do not increase resistance against a strong and transient oxidative stress exposure. We found that canonical stress responsive factors, such as DAF-16/FOXO, are dispensable for mir-60 loss to enhance oxidative stress resistance. Gene expression profiles revealed that genes encoding lysosomal proteases and those involved in the xenobiotic metabolism and pathogen defense response are up-regulated by the mir-60 loss. Detailed genetic studies and computational microRNA target prediction suggest that endocytosis components and a bZip transcription factor gene zip-10, which functions in innate immune response, are directly modulated by miR-60 in the intestine. Our findings suggest that the mir-60 loss facilitates adaptive response against chronic oxidative stress by ensuring the maintenance of cellular homeostasis. Overall design: To identify genes that respond to the mir-60 loss, RNA expression profiles were examined between the mir-60 loss mutant (mir-60(n4947)) and its control animals using the high-throughput sequencing technology. In this study, we used spe-9(hc88), a temperature-sensitive sterile strain, which has been shown in previous studies to have a lifespan similar to wild-type and widely used in gene expression studies to reduce the effect of RNA contamination from younger progenies. Both spe-9 single and mir-60;spe-9 double mutant animals were cultured at a restrictive temperature 23.5 °C, and treated with paraquat 5 mM during adulthood for chronic oxidative stress. Total RNAs were purified at the following time points: Day 0 young adult for both spe-9 and mir-60;spe-9 (just before paraquat exposure); Day 7 for both spe-9 and mir-60;spe-9 (50% survival time for spe-9); Day 10 for mir-60;spe-9 (50% survival time for mir-60;spe-9). For Day 0 controls, total RNAs were isolated twice independently for biological replicates. cDNA libraries were made for these 7 samples with indexed adapters using TruSeq Stranded mRNA Sample Prep Kit (Illumina), and sequenced on 2 lanes of flow cells on the HiSeq 2000/2500 platform, eventually providing 14 sequencing samples.
An intestinal microRNA modulates the homeostatic adaptation to chronic oxidative stress in <i>C. elegans</i>.
Specimen part, Treatment, Subject, Time
View SamplesOligodendrocytes (OLs) and myelin are critical for normal brain function and they have been implicated in neurodegeneration. Human neuroimaging studies have demonstrated that alterations in axons and myelin occur early in Alzheimer's Disease (AD) course. However, the molecular mechanism underlying the role of OLs in AD remains largely unknown. In this study, we systematically interrogated OL-enriched gene networks constructed from large-scale genomic, transcriptomic, and proteomic data in human AD postmortem brain samples. These robust OL networks were highly enriched for genes associated with AD risk variants, including BIN1. We corroborated the structure of the AD OL coexpression and gene-gene interaction networks through ablation of genes identified as key drivers of the networks, including UGT8, CNP, MYRF, PLP1, NPC1, and NDGR1. Perturbations of these key drivers not only caused dysregulation in their associated network neighborhoods, but also mimicked pathways of gene expression dysregulation seen in human AD postmortem brain samples. In particular, the OL subnetwork controlled by the AD risk gene PSEN1 was strongly dysregulated in AD, suggesting a potential role of PSEN1 in disrupting the myelination pathway towards the onset of AD. In summary, this study built and systematically validated the first comprehensive molecular blueprint of OL dysregulation in AD, and identified key OL- and myelination-related genes and networks as potential candidate targets for the future development of AD therapies. Overall design: The mouse knockout models have been previously described for each of Ugt8 (Coetzee et al., 1996), Cnp (Lappe-Siefke et al., 2003), and Plp1 (Klugmann et al., 1997). For each of the two conditions studied (control and homozygous knockout mice), five mice of either sex were sacrificed at postnatal day 20 and brains were flashed-frozen until analysis. The frontal cortex (FC) and cerebellum (CBM) were dissected out and individually processed. RNA was isolated using Trizol reagent and processed using Ribo-Zero rRNA removal. RNA-sequencing was performed using the Illumina HiSeq2000 with 100 nucleotide paired-end reads. RNA-sequencing reads were mapped to the mouse genome (mm10, UCSC assembly) using Bowtie (version 2.2.3.0), TopHat (version 2.0.11), and SamTools (version 0.1.19.0) using a read length of 100. Reads were converted to counts at the gene level using HTSeq on the BAM files from TopHat2 using the UCSC known genes data set.
Multiscale network modeling of oligodendrocytes reveals molecular components of myelin dysregulation in Alzheimer's disease.
Specimen part, Subject
View SamplesPartial induced pluripotent cells (iPSCs) are cell lines strayed from normal route from somatic cells to iPSCs and are immortalized. Mouse partial iPSCs are able to convert to real iPSCs by the exposure to 2i condition using MAPK and GSK3? inhibitors. However, the molecular mechanisms of this conversion are totally not known. Our piggyback vector mediated genome-wide screen revealed that Cnot2, one of core components of Ccr4-Not complex participates in this conversion. Subsequent analyses revealed other core components, i.e., Cnot1 and Cnot3 and Trim28 which is known to extensively share genomic binding sites with Cnot3 contribute to this conversion as well. Our bioinformatics analyses indicate that the major role of these factors in the conversion is the down-regulation of developmental genes in partial iPSCs.
Identification of Ccr4-not complex components as regulators of transition from partial to genuine induced pluripotent stem cells.
Sex, Specimen part
View SamplesXBP1 is a transcription factor that is induced by unconventional splicing associated with endoplasmic reticulum stress and plays a role in development of liver and plasma cells. We previously reported that brain derived neurotrophic factor (BDNF) leads to splicing of XBP1 mRNA in neurites, and that XBP1 is required for BDNF-induced neurite extension and branching. To search for the molecular mechanisms of how XBP1 plays a role in neural development, comprehensive gene expression analysis was performed in primary telencephalic neurons obtained from Xbp1 knockout mice at embryonic day 12.5. By searching for the genes induced by BDNF in wild type neurons but this induction was reduced in Xbp1 knockout mice, we found that upregulation of three GABAergic markers, somatostatin (Sst), neuropeptide Y (Npy), and calbindin (Calb1), were compromised in Xbp1 knockout neurons. Attenuated induction of Npy and Calb1 was confirmed by quantitative RT-PCR. In neurons lacking in Xbp1, upregulation of GABAergic markers was attenuated. Impaired BDNF-induced neurite extension in Xbp1 knockout neurons might be mediated by disturbed BDNF-induced differentiation of GABAergic interneurons.
Attenuated BDNF-induced upregulation of GABAergic markers in neurons lacking Xbp1.
Specimen part
View SamplesThe present study was conducted to evaluate the effects of the intake of three types of coffee (caffeinated, decaffeinated, and green unroasted coffee) on the livers of C57BL/6J mice fed a high-fat diet, and to extensively elucidate the physiological responses to coffee intake by analysing the findings obtained from a comprehensive transcriptomic analysis using DNA microarrays.
An integrated multi-omics study revealed metabolic alterations underlying the effects of coffee consumption.
Sex, Specimen part, Treatment
View SamplesRearrangements involving the NUP98 gene resulting in fusions to several partner genes occur in acute myeloid leukemia and myelodysplastic syndromes. This study demonstrates that the second FG repeat domain of the NUP98 moiety of the NUP98-HOXA9 fusion protein is important for its cell immortalization and leukemogenesis activities. We demonstrate that NUP98-HOXA9 interacts with MLL via this FG repeat domain and that, in the absence of MLL, NUP98-HOXA9-induced cell immortalization and leukemogenesis are severely inhibited. Molecular analyses indicate that MLL is important for the recruitment of NUP98-HOXA9 to the HOXA locus and for NUP98-HOXA9-induced HOXA gene expression. Our data indicate that MLL is crucial for NUP98-HOXA9 leukemia initiation.
MLL is essential for NUP98-HOXA9-induced leukemia.
No sample metadata fields
View SamplesNPM1 was reported to regulate the SOD2 gene expression through regulation of NF-kB. However, the effect of NPM1 on the NF-kB-dependent transcriptome has not been exmained.
Efficient DNA binding of NF-κB requires the chaperone-like function of NPM1.
Cell line
View Samples