Project description:NGS technology was used for high-throughput profiling of DNA loci bound by HDAC4 in muscle cells in growth condition. Chromatin was immunoprecipitated from C2C12 cells and IP with anti-HDAC4 antibody. Libraries were then generated, processed with Illumina cBot for cluster generation on the flowcell, and sequenced on single-end 50 bp mode at the multiplexing level requested on HiSeq2500. ChIP-Seq standard bioinformatics analysis and functional annotation revealed that HDAC4 predominantly binds to the gene body (UTR5, introns and exons) of coding genes, rather than to upstream regulatory regions or non-coding RNAs in proliferating muscle cells.
Project description:BACKGROUND: Histone deacetylase 4 (HDAC4) has been proposed as a target for the treatment of Amyotrophic Lateral Sclerosis (ALS) because it mediates nerve-skeletal muscle interaction and since its expression in skeletal muscle correlates with the severity of the disease. However, our recent studies on the skeletal muscle response upon long-term denervation highlighted the importance of HDAC4 in maintaining muscle integrity. METHODS: To fully identify the yet uncharacterized HDAC4 functions in ALS, we genetically deleted HDAC4 in skeletal muscles of a mouse model of ALS. Body weight, skeletal muscle, innervation and spinal cord were analyzed over time by morphological and molecular analyses. A transcriptome analysis was also performed to delineate the signaling modulated by HDAC4 in skeletal muscle of a mouse model of ALS. FINDINGS: HDAC4 deletion in skeletal muscle caused earlier ALS onset, characterized by body weight loss, muscle denervation and atrophy, and compromised muscle performance in ALS mice, although the main catabolic pathways were not activated. A transcriptome analysis identified the gene networks modulated by HDAC4 in ALS, revealing UCP1 as a top regulator that may be implicated in worsening ALS features. INTERPRETATION: HDAC4 plays an important role in preserving innervations and skeletal muscle in ALS, likely by modulating the UCP1 gene network. Our study highlights a possible risk in considering HDAC inhibitors for the treatment of ALS.
Project description:Muscle formation is a coordinated process driven by extensive gene expression changes where single cells fuse together to form multinucleated muscle fibers. Newly synthesized mRNAs are then regulated by RNA binding proteins(RBPs)affecting post-transcriptional transcripts metabolism. We determined how large gene expression changes affect the catalog of RBPs by studying proliferating and differentiated muscle cells in healthy and dystrophic conditions. Transcriptomic analysis showed that the expression of more than 7000 genes was affected during myogenesis. We identified 769 RBPs, of which 294 were muscle specific and 49 were uniquely shared with cardiomyocytes. A subset of 32 RBPs (half of which was muscle specific) showed preferential loading on target mRNAs in either myoblasts or myotubes. A large proportion of catalytic proteins was bound to mRNAs even though they lack classical RNA binding domains. Finally we show how the identification of cell specific RBPs enabled the identification biomarkers that can separate healthy individuals from dystrophic patients. Our data show how interactome data can shed light on new basic RNA biology as well as provide cell specific data that can be used for diagnostic purposes.
Project description:HDACs play crucial role in epigenetic modulation through deacetylation of histone and non-histone substrates in critical process of normal development and cancer. Moreover, HDAC inhibitors have been considered as new agent by effects such as cell cycle arrest, apoptosis, anti-angiogenic effects and autophagy and utilized in clinical applications for chemotherapy. we previously reported that HDAC 1, 4, 6 and 8 were higly expressed in MDA-MB-231 than MCF-7 cells and HDAC1, 6 and 8 excepting HDAC4 were associated with invasion that is very important factor in cancer progression. However, HDAC4 did not affect in invasion. To investigate interaction between chemoresistance and HDAC4 expression, we establish stable cells overexpressing HDAC4 in MCF-7 cells. Cells overexpressed HDAC4 were increased cytotoxicity about 5-FU and identified 356 differentially expressed genes using Ilumina array. Based on array result, we selected SMAD4 as a candidate gene related with chemoresistance because SMAD4 was previously reported evaluation of chemoresistance to 5-FU. We purpose that HDAC4 regulated with SMAD4 expression through acetylation in SMAD4 promoter region. HDAC4 directly bound a part of SMAD4 promoter. Total RNA obtained from cells overexpressed HDAC4 cDNA in MCF-7 compared to control cells.
Project description:We analyzed the genome wide distributions of HDAC1, HDAC4, HDAC7 in Th17 cells. We find that majority of HDAC4 and HDAC7 binding sites are HDAC1 bound. TMP269 inhibits HDAC4 and HDAC7 at promoter sites of Th17 negative regulator genes, leading to their upregulation through increased H3, H4 acetylation.
Project description:Access to DNA is the first level of control in regulating gene transcription, a control that is also critical for maintaining DNA integrity. Cellular senescence is characterized by profound transcriptional rearrangements and accumulation of DNA lesions. Here, we discovered an epigenetic complex between HDAC4 and HDAC1/HDAC2 that is involved in the erase of H2BK120 acetylation. The HDAC4/HDAC1/HDAC2 complex modulates the efficiency of DNA repair by homologous recombination, through dynamic deacetylation of H2BK120. Deficiency of HDAC4 leads to accumulation of H2BK120ac, impaired recruitment of BRCA1 and CtIP to the site of lesions, accumulation of damaged DNA and senescence. In senescent cells this complex is disassembled because of increased proteasomal degradation of HDAC4. Forced expression of HDAC4 during RAS-induced senescence reduces the genomic spread of γH2AX and affects H2BK120ac levels, which are increased in DNA-damaged regions accumulated during RAS-induced senescence. In summary, degradation of HDAC4 during senescence causes the accumulation of damaged DNA and contributes to the activation of the transcriptional program controlled by super-enhancers that maintains senescence.
Project description:Hdac4 has been found to modulate symptoms in Huntington's Disease (HD) mouse models through an uknown mechanism unrelated to any enzymatic activity. We investigated the protein-protein interactions to gain insight into the role of Hdac4 in HD.
Project description:HDACs play crucial role in epigenetic modulation through deacetylation of histone and non-histone substrates in critical process of normal development and cancer. Moreover, HDAC inhibitors have been considered as new agent by effects such as cell cycle arrest, apoptosis, anti-angiogenic effects and autophagy and utilized in clinical applications for chemotherapy. we previously reported that HDAC 1, 4, 6 and 8 were higly expressed in MDA-MB-231 than MCF-7 cells and HDAC1, 6 and 8 excepting HDAC4 were associated with invasion that is very important factor in cancer progression. However, HDAC4 did not affect in invasion. To investigate interaction between chemoresistance and HDAC4 expression, we establish stable cells overexpressing HDAC4 in MCF-7 cells. Cells overexpressed HDAC4 were increased cytotoxicity about 5-FU and identified 356 differentially expressed genes using Ilumina array. Based on array result, we selected SMAD4 as a candidate gene related with chemoresistance because SMAD4 was previously reported evaluation of chemoresistance to 5-FU. We purpose that HDAC4 regulated with SMAD4 expression through acetylation in SMAD4 promoter region. HDAC4 directly bound a part of SMAD4 promoter.