The effects of Hmgb1 depletion on gene expression in murine cells
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ABSTRACT: 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
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.
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:HMGB1 and HMGB2 are members of the High Mobility Group (HMG) protein superfamily that contain a DNA binding domain (HMG-Box), and their overexpression has been related to main cancer hallmarks, tumor progression, metastasis formation and bad prognosis. We have used yeast two hybrid and affinity purification-mass spectrometry to explore HMGB1 and HMGB2 protein interactions in prostate and ovarian epithelial cells.
Project description:Macrophages are key inflammatory immune cells that display dynamic phenotypes and functions in response to their local microenvironment. In different conditions, macrophage polarization can be induced by high-mobility group box 1 (HMGB1), a nuclear DNA-binding protein that activates innate immunity. This study investigated the phenotypes of murine bone-marrow-derived macrophages (BMDMs) induced by different HMGB1 redox isoforms via bulk RNA sequencing (RNAseq).
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: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: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.