Project description:The purpose of this study is to generate mRNA effect profle of KH-3, an inhibitor of RNA-binding protein HuR, in human breast cancer cell line MDA-MB-231 cells by RNA sequencing. Total RNA from cells treated with DMSO or KH-3 was collected for library prepareation and deep sequencing, in duplicate, using Illumina Hiseq 2500 system. About 30 million sequence reads per sample were mapped against the transcript databases annotated in GENCODE v24 using STAR default parameters. The read counts for each transcript were calculated using eXpress. The differentially expressed transcripts were detected using DESeq2 with a q-value cutoff of 0.05.
Project description:The purpose of this study is to generate RNA binding profile of RNA-binding protein HuR in human breast cancer cell line MDA-MB-231 cells by ribonucleoprotein immunoprecipitation sequencing (RIP-deq). RNA immunoprecipitated by mouse anti-HuR antibody or mouse IgG was collected for library prepareation and deep sequencing, in duplicate, using Illumina Hiseq 2500 system. About 30 million sequence reads per sample were mapped to the human genome (build hg38), the corresponding peaks were then detected and annotated. Finally, the RIP peaks that correspond to significant transcript abundance change were identified and compiled.
Project description:Comprehensive meta-analysis and target screening confirmed that the mRNA-binding protein of ELAV-family HuR is oncogenic and universally upregulated in brain tumors, which highlight HuR as an universal chemotherapeutic target. HuR functionality in cancer cells is strictly dependent on HuR nuclear/cytoplasmic shuttling and dimerization; therefore, we developed a new class of inhibitors of HuR protein dimerization by utilizing medicinal chemistry techniques and reporter cell-based assay of HuR dimerization. The therapeutic potentials of lead compound (SRI-42127) were evaluated in five primary patient-derived glioma xenolines of classic, proneural, and mesenchymal subtypes, in vitro, and in mouse glioma model, in vivo. The Illumina global RNA-Sequencing was performed on PDGx-derived glioma neurospheres of different subtypes after treatment with DMSO (control) or SRI-42127 (3 uM) for 12 h to analysis transcripts and cell-signaling pathways affected by new inhibitor of HuR dimerization.
Project description:The 3’ UTR of messenger RNAs serves as the regulatory region that mediates post-transcriptional control by microRNAs and RNA-binding proteins (RBPs). Aside from individual sequence-specific binding and regulation, examples of interaction between these factors at particular 3’ UTR sites have emerged in recent studies. However, the whole picture of such higher-order regulatory modules across the transcriptome is lacking. Here, we investigate the interactions between HuR, a ubiquitous RBP, and Ago2, a core effector of the miRNA pathway, at the transcriptome-wide level. Using HITS-CLIP, we map HuR and miRNA binding sites on human 3’UTRs and assess their co-occurrence. Additionally, we demonstrate global effects of HuR knockdown on Ago2 occupancy, suggesting a co-regulatory relationship. Focusing on sites of Ago2-HuR overlap, 13 candidates were screened in luciferase reporter assays, compared to miRNA site mutant controls. Eleven of the sites showed a repressive activity, which displayed significant de-repression upon subsequent testing of the reporters in Dicer-null cells, substantiating miRNA dependence. To experimentally test for HuR’s role in co-regulation, we tested the reporters in CRISPR-generated HuR KO cells. Three of the miRNA sites demonstrated altered activities, indicating that HuR has an effect on miRNA repression at those sites. Our study presents an efficient search and validation system for studying miRNA-HuR interactions, which expands our understanding of the combinatorial post-transcriptional control of gene expression at the 3’ UTR.
Project description:HuR is a regulator of mRNA turnover or translation of inflammatory genes through binding to adenylate-uridylate-rich elements (ARE) and related motifs present in the 3’untranslated region (UTR) of mRNAs. We aimed to identify HuR targets in the human airway epithelial cell line BEAS-2B challenged with TNFa plus IFNg, a strong stimulus for inflammatory epithelial responses. Ribonucleoprotein (RNP) complexes from resting and cytokine-treated cells were immunoprecipitated (IP) using anti-HuR and isotype-control antibody, and eluted mRNAs were reverse-transcribed and hybridized to an inflammatory-focused gene array. The chemokines CCL2, CCL8, CXCL1 and CXCL2 ranked highest among 27 signaling and inflammatory genes significantly enriched in the HuR RNP-IP from stimulated cells over the control IP. Among these, 20 displayed published HuR binding motifs. Association of HuR with the four endogenous chemokine mRNAs was validated by single-gene RNP-IP, and shown to be 3’UTR-dependent by biotin pull-down assay. Cytokine treatment increased mRNA stability only for CCL2 and CCL8, and transient silencing and overexpression of HuR affected only CCL2 and CCL8 expression in primary and transformed epithelial cells. Cytokine-induced CCL2 mRNA was predominantly cytoplasmic; conversely, CXCL1 mRNA remained mostly nuclear and unaffected, as CXCL2, by changes in HuR levels. Increase in cytoplasmic HuR and HuR target expression partially relied on the inhibition of AMP-dependent kinase, a negative regulator of HuR nucleocytoplasmic shuttling. We postulate that HuR critically regulates the epithelial response, by associating with multiple adenylate-uridylate-rich elements (ARE)-bearing, functionally related inflammatory transcripts. On the basis of genome-wide studies probing the relationship between RNA-binding proteins and the functional profile of their associated transcripts, we combined the specific HuR immunoprecipitation of RNPs and the genome-scale microarray to profile the target mRNAs of HuR in the human airway epithelial cell line BEAS-2B challenged with very strong inflammatory stimulation, TNFa plus IFNG. The array platform we used is the Human Autoimmune and Inflammatory Response Gene Array (SuperArray Bioscience, Frederick, MD). To validate the association of HuR and its target mRNAs, we planned to apply biotin pull-down assay. HuR overexpression and knockdown assays were also planned to further verify the association of HuR and its target mRNAs. Overall, we did three biological replicates for the IP array experiments, which include both IgG1 control IP and HuR IP arrays.
Project description:Integrative regulatory mapping indicates that the RNA-binding protein HuR (ELAVL1) couples pre-mRNA processing and mRNA stability In this dataset, we employed two distinct experiments. 1) HuR RIP-chip to identify mRNA targets of HuR. 2) HuR knockdown to identify mRNAs whose expression are dependent on HuR. All 12 samples were normalized with PLIER using Affymetrix power tools. To identify RNA targets of HuR, HuR RIP samples were compared to Mock RIP samples. To identify RNA regulated by HuR, HuR knockdown samples were compared to mock knockdown samples.
Project description:In this study, we applied a novel small molecule inhibitor of HuR to define the functional role of HuR in the acute response to I/R injury and gain a better understanding of the HuR-dependent mechanisms during post-ischemic myocardial remodeling. Our results show an early post-ischemic increase in HuR activity that is necessary for inflammatory gene expression in cardiomyocytes. Despite the early reductions inflammatory gene expression, HuR inhibition has no effect on initial infarct size at 24-hours post-I/R. However, in agreement with previously published work by our group using a pressure overload model, we do see a protection with regard to pathological remodeling and cardiac function at two weeks post-I/R upon HuR inhibition. RNA-sequencing analysis of neonatal rat ventricular myocytes (NRVMs) post-LPS treatment to model damage associated molecular pattern (DAMP)-mediated activation of toll like receptors (TLRs) demonstrates a broad HuR-dependent regulation of pro-inflammatory chemokine and cytokine gene expression in cardiomyocytes. Importantly, we show that conditioned media from NRVMs pre-treated with HuR inhibitor loses the ability to induce inflammatory gene expression in bone marrow derived macrophages (BMDMs) compared to NRVMs treated with LPS alone. Functionally, HuR inhibition in NRVMs also reduces their ability to induce endocrine migration of peripheral blood monocytes in vitro and reduces post-ischemic macrophage infiltration to the heart in vivo. In summary, these results suggest a HuR-dependent expression of pro-inflammatory gene expression by cardiomyocytes that leads to subsequent monocyte recruitment and macrophage activation in the post-ischemic myocardium.
Project description:Cell death is an important host defense in response to viral infections. In this study,we performed an unbiased whole-genome CRISPR/Cas9 screen in A549 lung adenocarcinoma cells to identify potential regulators involved in cell death triggered dsRNA, a common byproduct of viral replication. Of several top candidate genes, we identified the RNA binding protein ELAV like protein 1 (ELAVL1) (ELAVL1, also called HuR) that encodes Hu antigen R (HuR). Depletion of HuR by gene editing led to less cell death induced by dsRNA. We further demonstrated that HuR regulated apoptosis, and the RNA recognition motif (RRM) 3 of HuR was essential for its proapoptotic function. HuR bound mRNA of anti-apoptotic gene BCL2. HuR depletion had no influence on BCL2 mRNA levels, but instead downregulated the BCL2 translation. Polysome fractionation studies showed that HuR retarded the BCL2 mRNA in the non-translating pool of polysomes. Moreover, protection from dsRNA-induced apoptosis by HuR depletion required the presence of BCL2, indicating that the proapoptotic function of HuR is executed by suppressing BCL2. Consistently, HuR regulated apoptosis induced by infection of encephalomyocarditis or Semliki Forest virus, two unrelated positive strand RNA viruses. Collectively, our work identified a suite of proteins that regulate dsRNA-induced cell death, and elucidated the mechanism by which HuR acts as a pro-apoptotic factor.