HMGB1 prefers to interact with structural RNAs and regulates rRNA methylation modification and translation in HeLa cells
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ABSTRACT: High-mobility group B1 (HMGB1) is both a DNA binding nuclear factor modulating transcription and a crucial cytokine that mediates the response to both infectious and noninfectious inflammation.Recently data show that HMGB1is a RNA-binding protein also affecting splicing.Howerer we still lack understanding of the functional roles of HMGB1 in protein translation.To address theses we applied Improved RNA immunoprecipitation by UV cross-linking and deep sequencing (iRIP-seq) experiment revealed that HMGB1 selectively bound to mRNAs and structured RNAs. We also integrated RNA-seq data from knockdown and overexpress HMGB1 to show that HMGB1 affected some genes expression. Taken these data together, our findings highlight that HMGB1 binds to multiple RNA species including mRNA and snoRNA
Project description:Testing the consequences of the absence of the chromatin-associated HMGB1 protein on the transcriptome in Arabidopsis. Keywords: Comparison of mutant and wildtype samples. Four replicate RNA extractions were performed of each genotype using independent pools of plants. hmgb1#1 (Cy5) vs. Col-0#1 (Cy3) Col-0#2 (Cy5) vs. hmgb1#2 (Cy3) dye-swap hmgb1#3 (Cy5) vs. Col-0#3 (Cy3) Col-0#5 (Cy5) vs. hmgb1#4 (Cy3) dye-swap Samples were hybridized in two dye-swaps. The data were normalized over all 4 hybridizations to obtain one, single log-ratio(Sample/Reference). The raw data files of all four of the hybridizations are attached to the Sample.
Project description:Purpose: Determine the mechanism of high mobility group box 1 (HMGB1)-induced signaling in melanocytes. Method: Primary human epidermal melanocytes were treated with HMGB1 (1 μg/ml) and incubated for 24 h. Total RNA (500 ng) from melanocytes were extracted and subjected to library synthesis. Results: HMGB1-treated melanocytes exhibited upregulation of cell death and type 1 interferon-related genes. Conclusion: HMGB1-induced melanocyte signaling was well evaluated using RNA sequencing.
Project description:High Mobility Group Box 1 (HMGB1) is a highly abundant and evolutionarily conserved non-histone chromatin component with the ability to bind and bend DNA. The protein is involved in fundamental nuclear processes including nucleosome sliding, transcription, replication, V(D)J recombination and DNA transposition. To assess the functional impact of HMGB1 on transcription we performed gene expression profile analyses of mouse embryonic fibroblasts, wild-type or knockout for the Hmgb1 gene 2 genetic backgrounds: wild-type (Wt), Hmgb1-/- (KO), 3 biological replicates (rep1, rep2, rep3; S phase synchronized cells in duplicate only), no technical replicates. Each pair of wt and Hmgb1-/- MEFs was isolated from embryos born from a single Hmgb1+/- mother crossed with a Hmgb1 +/- male. Total RNAs from three pairs of MEFs, derived from three different mothers and cultured up to passage 3, were extracted using mirVana miRNA Isolation Kit (Ambion) and analyzed on the Illumina BeadsArray platform.
Project description:High Mobility Group Box 1 (HMGB1) is a highly abundant and evolutionarily conserved non-histone chromatin component with the ability to bind and bend DNA. The protein is involved in fundamental nuclear processes including nucleosome sliding, transcription, replication, V(D)J recombination and DNA transposition. To assess the functional impact of HMGB1 on transcription we performed gene expression profile analyses of HeLa cells stably transfected with an anti-HMGB1 shRNA expressing plasmid or a control plasmid. 2 stable clones: control HeLa, Hmgb1-knocked down HeLa, 3 technical replicates. Hmgb1 knockdown HeLa cells were prepared by stable transfection with the plasmid Hmgb1shRNA-pSuperior.puro or, as a mock control, with the empty vector pSuperior.puro (Invitrogen). Transfection was made starting from 500 thousands (500K) or 5 milions (5mil) cells. Transfected cells were selected with puromycin and single resistant clones were picked, amplified and analyzed for HMGB1 expression by western blot. A clone containing less then 10% of the wt amount of HMGB1 was selected for further experiments. Total RNAs were extracted using Quiagen RNeasy kit and analyzed on the Illumina BeadsArray platform in 2 technical replica (2 arrays).
Project description:Upon muscle injury the high mobility group box 1 (HMGB1) protein is up-regulated and secreted to initiate reparative responses. Here we show that HMGB1 controls myogenesis both in vitro and in vivo, during development and after adult muscle injury. HMGB1 expression in muscle cells is regulated at the translational level: the miRNA miR-1192 inhibits HMGB1 translation and the RNA-binding protein HuR promotes it. HuR binds to a cis-element, HuRBS, located in the 3'UTR of the HMGB1 transcript, and at the same time miR-1192 is recruited to an adjacent seed element. The binding of HuR to the HuRBS prevents the recruitment of Argonaute 2 (Ago2), overriding miR-1192-mediated translation inhibition. Depleting HuR reduces myoblast fusion and silencing miR-1192 re-establishes the fusion potential of HuR-depleted cells. We propose that HuR promotes the commitment of myoblasts to myogenesis by enhancing the translation of HMGB1 and suppressing the translation inhibition mediated by miR-1192. RNA content was extracted following immunoprecipitation of HuR using a monoclonal antibody (3A2) and the levels of mRNA were compared to an IgG control in order to determine which transcripts were enriched in the HuR ribonucleoprotein complex.
Project description:Upon muscle injury the high mobility group box 1 (HMGB1) protein is up-regulated and secreted to initiate reparative responses. Here we show that HMGB1 controls myogenesis both in vitro and in vivo, during development and after adult muscle injury. HMGB1 expression in muscle cells is regulated at the translational level: the miRNA miR-1192 inhibits HMGB1 translation and the RNA-binding protein HuR promotes it. HuR binds to a cis-element, HuRBS, located in the 3'UTR of the HMGB1 transcript, and at the same time miR-1192 is recruited to an adjacent seed element. The binding of HuR to the HuRBS prevents the recruitment of Argonaute 2 (Ago2), overriding miR-1192-mediated translation inhibition. Depleting HuR reduces myoblast fusion and silencing miR-1192 re-establishes the fusion potential of HuR-depleted cells. We propose that HuR promotes the commitment of myoblasts to myogenesis by enhancing the translation of HMGB1 and suppressing the translation inhibition mediated by miR-1192. RNA content was extracted following immunoprecipitation of HuR using a monoclonal antibody (3A2) and the levels of mRNA were compared to an IgG control in order to determine which transcripts were enriched in the HuR ribonucleoprotein complex.
Project description:Mutant ataxin-1 (Atxn1), which causes spinocerebellar ataxia type 1 (SCA1), binds to and impairs the function of high mobility group box 1 (HMGB1), a critical nuclear protein that regulates DNA architectural changes essential for DNA damage repair and transcription. In this study, we established that transgenic or virus vector-mediated supplementation of HMGB1 ameliorates motor dysfunction and elongates lifespan in mutant Atxn1 knock-in (Atxn1-KI) mice. We identified mitochondrial DNA damage repair by HMGB1 as a novel molecular basis for this effect, in addition to the mechanisms already associated with HMGB1 function, such as nuclear DNA damage repair and nuclear transcription. The dysfunction and the improvement of mitochondrial DNA damage repair functions are tightly associated with the exacerbation and rescue, respectively, of symptoms, supporting the involvement of mitochondrial DNA quality control by HMGB1 in SCA1 pathology. Moreover, we show that the rescue of Purkinje cell dendrites and dendritic spines by HMGB1 could be downstream effects. Although extracellular HMGB1 triggers inflammation mediated by toll-like receptor and receptor for advanced glycation end products, upregulation of intracellular HMGB1 does not induce such side effects. Thus, viral delivery of HMGB1 is a candidate approach by which to modify the disease progression of SCA1 even after its onset.
Project description:HMGB1 is important for tumor development of autophagy-deficient liver. However, detailed molecular signals impacted by HMGB1 is unclear. RNA seq data will provide a comprehensive gene expression profile data that will help to dissect the signaling pathways affected by HMGB1 during tumorigenesis in autophagy deficient liver.
Project description:Neuroinflammation is a crucial process for the loss of retinal ganglion cells (RGC), a major characteristic of glaucoma. High expression of high mobility group box protein 1 (HMGB1) plays a detrimental role in inflammatory processes and is elevated in the retinas of glaucoma patients. Therefore, this study aimed to investigate the effects of intravitreal injection of an anti-HMGB1 monoclonal antibody (anti-HMGB1 Ab) in an experimental animal model of glaucoma. Two groups of Spraque Dawley rats received episcleral vein occlusion to chronically elevate intraocular pressure (IOP): (1) IgG group, intravitreal injection of an unspecific IgG as a control, n=5, (2) HMGB1 group, intravitreal injection of an anti-HMGB1 Ab, n=6. IOP, retinal nerve fiber layer thickness (RNFLT), and the retinal flash response was monitored longitudinally. Post-mortem examinations included immunohistochemistry, microarray, and mass spectrometric analysis. RNFLT was significantly increased in the HMGB1 group compared to the IgG group (p<0.001). RGC density showed improved neuronal cell survival in the retina in HMGB1 compared to the IgG group (p<0.01). Mass spectrometric proteomic analysis of retinal tissue showed increased abundance of RNA metabolism-associated heterogeneous nuclear ribonucleoproteins (hnRNPs), such as hnRNP U, D, and H2, in animals injected with the anti-HMGB1 Ab, indicating that application of the antibody may cause increased gene expression. Microarray analysis showed significantly decreased expression of C-X-C motif chemokine ligand 8 (CXCL8, p<0.05) and connective tissue growth factor (CTGF, p<0.01) in the HMGB1 group. Thus, these data suggest that intravitreal injection of anti-HMGB1 Ab reduced HMGB1-dependent inflammatory signaling and mediated RGC neuroprotection.
Project description:To analyze cell profiles in pancreatic tissue, single-cell RNA-seq of CD45-negative cells was performed using pancreatic tissue obtained in the eighth week after HMGB1 fragment injection was begun. After conventional quality check and filtering, we recovered pancreas cells from normal pancreas, control group pancreas, and HMGB1 group pancreas. The UMAP plots depicted 11 distinct cell clusters from the three groups, PDGFRα+ cells had the most significant number of clusters, which exhibited a high level of Col1α1 gene expression in the bubble plot.Compared with the control and HMGB1 groups, the distribution of the PDGFRα+ cell cluster was skewed in the normal group. We focused on PDGFRα+ cell clusters that secrete large amounts of collagen and extracellular matrix components, which are central to the pathogenesis of CP. Many genes were significantly expressed in contrasting ways, gene clusters that were upregulated in the control compared with the normal group were downregulated in the HMGB1 compared with the control group. In contrast, gene groups that were downregulated in the control compared with the normal group were upregulated in the HMGB1 compared with the control group. HMGB1 fragment exposure was associated with a shift in the gene expression pattern of CP toward that of the normal pancreas. Expression of Ccn2 and Ccn1 was upregulated in the control group compared with the normal group but downregulated in the HMGB1 group compared with the control group. Pten expression was downregulated in the control versus normal group but upregulated in the HMGB1 group compared with the controls. Extracellular matrix–related genes in the pancreas were altered with HMGB1 fragment administration.