Project description:We used microarrays to study the global gene expression and identified differentially expressed genes in CLOCK inducibel shRNA knockdown GSC272 cells, aiming to identify genes and pathways that are regulated by CLOCK.
Project description:The circadian clock is intricately connected with metabolism, however the precise details of these connections are incomplete. Here we used high temporal resolution metabolite profiling to determine circadian regulation of mouse liver and cell autonomous metabolism. In mouse liver, we found ~50% of metabolites were circadian, with strong enrichment of the nucleotide, amino acid, and methylation pathways. In U2OS cells, 27% of metabolites were circadian, including amino acids and NAD biosynthesis, also clock controlled in liver. To assess whether cell autonomous metabolite rhythms were clock-dependent, we used RNAi to perturb Bmal1, Cry1, and Cry2. Bmal1 knockdown eliminated most metabolite rhythms, while Cry1 generally shortened and Cry2 lengthened rhythms. Surprisingly, we found Cry1 knockdown induced 8 hr rhythms in amino acid, methylation, and vitamin metabolites, decoupling metabolite and transcriptional rhythms. These results provide the first comprehensive views of circadian liver and cell autonomous metabolism.
Project description:Here, we report that the disruption of circadian clock obtained through shRNA-mediated knockdown of Clock and Bmal1 genes negatively impacted the in vitro growth of a T-cell acute lymphoblastic leukemia (T-ALL) cell line. We performed gene expression profiling analysis of RPMI-8402 cell line upon knock-down of the circadian genes Clock and Bmal1. We found that circadian clock directly infuences the expression of genes, such as IL20RB, involved in JAK/STAT signaling, making the T-ALL cells more responsive to Interleukin 20 (IL20).
Project description:We investigated the functions/pathways affected by SPEN knockdown in breast cancer by global expression profiling in a cell model, where the human breast cancer cell line, MCF-7, were transfected with an shRNA targeting SPEN mRNA.
Project description:The circadian clock is comprised of proteins that form negative feedback loops, which regulate the timing of global gene expression in a coordinated 24 hour cycle. As a result, the plant circadian clock is responsible for regulating numerous physiological processes central to growth and survival. To date, most plant circadian clock studies have relied on diurnal transcriptome changes to elucidate molecular connections between the circadian clock and observable phenotypes in wild-type plants. Here, we have combined high-throughput RNA-sequencing and mass spectrometry to comparatively characterize the lhycca1, prr7prr9, gi and toc1 circadian clock mutant rosette transcriptome and proteome at the end-of-day and end-of-night.
Project description:SETD1A is a histone H3K4 methyltransferase and function as a coactivator for nuclear receptors (NRs) and other transcription factors. We performed genome-wide gene expression analysis in non-specific siRNA transfected or SETD1A knockdown MCF-7 cells to investigate global gene expression changes induced by SETD1A knockdown.
Project description:The molecular mechanisms underlying human brain evolution are not fully understood; however, previous work suggested that expression of the transcription factor CLOCK in the human cortex might be relevant to human cognition and disease. In this study, we investigated this novel transcriptional role for CLOCK in human neurons by performing chromatin-immunoprecipitation sequencing for endogenous CLOCK in adult neocortex and RNA-sequencing following CLOCK knockdown in differentiated human neurons in vitro. These data suggested that CLOCK regulates expression of genes involved in neuronal migration, and a functional assay showed that CLOCK knockdown increased neuronal migratory distance. Furthermore, dysregulation of CLOCK disrupts co-expressed networks of genes implicated in neuropsychiatric disorders, and the expression of these networks are driven by hub genes with human-specific patterns of expression. Thus, these data support a role for CLOCK-regulated transcriptional cascades involved in human brain evolution and function.
Project description:CtBP is a global co-repressor by serving as transcriptional factor in multiple pathways. CtBP functioned as transcriptional factor by recruiting other cofactors such as G9a, HDAC1 and PcG proteins. CtBP is found to be over enriched in several type of tumor samples. To dipict the role of CtBP in globally regulating gene expression, we applied gene microarray technology to find out what subgroups of genes are mainly affected. 6 MCF-7 cell samples, 3 with CtBP knockdown and 3 with control knock down.
Project description:Determining the mechanisms of action of drug molecules that modulate circadian rhythms is critical to develop novel compounds to treat clock disorders. Here we employed Phenotypic Proteomic Profiling (PPP) integrating multipronged proteomics approaches including global proteome, phosphoproteome, kinome mapping, and proteome-wide profiling of thermal stability (TPP) to systematically determine convergent molecular targets of four circadian period lengthening compounds (Longdaysin, Roscovitine, Purvalanol A, and SP600125) in human cells. We demonstrate convergent changes in phosphorylation level and activity of several proteins and kinases involved in vital signaling pathways including MAPK, NGF, BCR, AMPK, and mTOR signaling by the compounds. Kinome profiling using desthiobiotin-ATP enrichment quantitative proteomics and radiometric assays further indicated inhibition of CKId, ERK1/2, CDK2/7, TNIK and STK26 activity as a common mechanism of action for the compounds. Pharmacological or genetic inhibition of several convergent kinases resulted in circadian period lengthening, establishing them as novel bone fide circadian targets. TPP analysis using live cells revealed binding of these drugs to clock regulatory kinases, signaling molecules, and ubiquitination mediator (F-box) proteins. Phenotypic proteomic profiling thus establishes a set of novel circadian clock effectors.