Project description:Loss or reduced expression of lysine demethylases (KDMs) is linked to neurodevelopmental disorders and intellectual disability. Given the phenotypic similarities between KDM1A and KDM5C deficient mice, and the convergence of both enzymes in maintaining a repressive state via H3K4 demethylation, we examined their functional interaction using double-inducible, forebrain-specific knockouts (dKDM-ifKOs). These mice showed transcriptional and epigenetic dysregulation beyond the additive effects of individual knockouts, including stronger ectopic expression of non-neuronal genes in hippocampal neurons. Thousands of de novo H3K4me3-enriched regions emerged, indicating synergistic disruption of chromatin regulation. In line with these molecular changes, dKDM-ifKOs displayed more severe behavioral impairments than the single ifKOs, along with altered hippocampal expression of ion channels and increased excitability of CA1 pyramidal neurons. These findings underscore the joint role of ID-linked KDMs in regulating cell-type-specific gene silencing and H3K4 methylation levels to safeguard neuronal identity and responsiveness, as well as cognitive function
Project description:Loss or reduced expression of lysine demethylases (KDMs) is linked to neurodevelopmental disorders and intellectual disability. Given the phenotypic similarities between KDM1A and KDM5C deficient mice, and the convergence of both enzymes in maintaining a repressive state via H3K4 demethylation, we examined their functional interaction using double-inducible, forebrain-specific knockouts (dKDM-ifKOs). These mice showed transcriptional and epigenetic dysregulation beyond the additive effects of individual knockouts, including stronger ectopic expression of non-neuronal genes in hippocampal neurons. Thousands of de novo H3K4me3-enriched regions emerged, indicating synergistic disruption of chromatin regulation. In line with these molecular changes, dKDM-ifKOs displayed more severe behavioral impairments than the single ifKOs, along with altered hippocampal expression of ion channels and increased excitability of CA1 pyramidal neurons. These findings underscore the joint role of ID-linked KDMs in regulating cell-type-specific gene silencing and H3K4 methylation levels to safeguard neuronal identity and responsiveness, as well as cognitive function
Project description:Loss or reduced expression of lysine demethylases (KDMs) is linked to neurodevelopmental disorders and intellectual disability. Given the phenotypic similarities between KDM1A and KDM5C deficient mice, and the convergence of both enzymes in maintaining a repressive state via H3K4 demethylation, we examined their functional interaction using double-inducible, forebrain-specific knockouts (dKDM-ifKOs). These mice showed transcriptional and epigenetic dysregulation beyond the additive effects of individual knockouts, including stronger ectopic expression of non-neuronal genes in hippocampal neurons. Thousands of de novo H3K4me3-enriched regions emerged, indicating synergistic disruption of chromatin regulation. In line with these molecular changes, dKDM-ifKOs displayed more severe behavioral impairments than the single ifKOs, along with altered hippocampal expression of ion channels and increased excitability of CA1 pyramidal neurons. These findings underscore the joint role of ID-linked KDMs in regulating cell-type-specific gene silencing and H3K4 methylation levels to safeguard neuronal identity and responsiveness, as well as cognitive function
Project description:Here, we show that the Kdm5c/Smcx member of the Jarid1 family of H3K4 demethylases is recruited to both enhancer and core promoter elements in ES and neuronal progenitor cells (NPC). Knockdown of Kdm5c deregulates transcription via a local increase in H3K4me3. While at core promoters the function of Kdm5c is to restrict transcription, loss of Kdm5c impairs enhancer function. Remarkably, an impaired enhancer function activates promoter activity from Kdm5c-bound intergenic regions. Our results demonstrate that the Kdm5c demethylase plays a crucial role in the functional identity and discrimination of enhancers and core promoters. We speculate that this is related to recruitment of H3K4me3 binders like the TFIID and NURF complexes6-8. Providing functional identity to genomic regions through balancing enzymes that deposit and remove histone modifications may prove to be a general epigenetic mechanism for the functional indexing of eukaryotic genomes. Examination of the KDM5C binding sites in mouse embryonic stem cells and in neuronal progenitor cells. Effect of KDM5C knock down on H3K4me3 and H3K4me1 levels and gene expression.
Project description:The functional organization of eukaryotic genomes correlates with specific patterns of histone methylations. Regulatory regions in genomes like enhancers and promoters differ in their extent of methylation of histone H3 at lysine-4 (H3K4), but it is largely unknown how the different methylation states are specified and controlled. Here, we show that the Kdm5c/Jarid1c/SMCX member of the Kdm5 family of H3K4 demethylases can be recruited to both enhancer and promoter elements in embryonic stem cells and neuronal progenitor cells via gene-specific transcription factors. Knockdown of Kdm5c deregulates transcription via local increases in H3K4me3. Our data show that restricting H3K4me3 modification at core promoters dampens transcription, but Kdm5c is required at enhancers for their full activity. Remarkably, an impaired enhancer function activates the intrinsic promoter activity of Kdm5c-bound distal elements. Our results demonstrate that the Kdm5c demethylase plays a crucial and dynamic role in the functional discrimination between enhancers and core promoters. RNA from four independent cultures from each sh Kdm5c #1, sh Kdm5c #2 and non-targeting shRNA polyclonal cell lines were hybridized in dye-swap against a common reference of RNA from IB10 ES cells.
Project description:Histone-modifying enzymes (HMEs) are critical regulators of tumorigenesis through epigenetic reprogramming. While mutations in HMEs are recognized drivers of cancer epigenome dysregulation, systematic comparative analyses of their mutational impacts and functional divergence across malignancies remain underexplored. This study addresses this gap by investigating three HMEs—KDM5C (H3K4me3 demethylase), KMT2B (H3K4me3 methyltransferase), and KDM6A (H3K27me3 demethylase)—frequently mutated in diverse cancers. Using CRISPR/Cas9 knockout cell lines, we performed integrated multi-omics profiling encompassing genome-wide chromatin accessibility, transcriptomics, and chromatin-bound proteomics. Contrary to expectations that KMT2B loss (H3K4me3 depletion) and KDM5C loss (H3K4me3 accumulation) would induce opposing transcriptional programs, or that KDM6A deficiency (H3K27me3 accumulation) would exhibit distinct regulatory effects, our analyses revealed striking discrepancies between transcriptional outputs and chromatin-associated proteomic states across all three knockouts. Notably, each HME knockout elicited distinct transcriptional regulatory patterns, challenging conventional assumptions about their antagonistic or synergistic functions. These findings highlight context-dependent functional hierarchies among HMEs and underscore the necessity of multi-dimensional profiling to resolve epigenetic regulatory complexity. Our work advances the mechanistic understanding of cancer epigenetics and provides a framework for elucidating tumorigenic vulnerabilities linked to HME dysregulation.
Project description:To uncover novel epigenetic regulators in AML, we performed an in vivo short hairpin RNA (shRNA) screen in the context of Cebpa mutant AML. This led to the identification of the Histone 3 Lysine 4 (H3K4) demethylase, KDM5C, as a novel tumor suppressor in AML. KDM5C potentially functions as a transcriptional repressor via its demethylase activity at promoters, and dysregulation could therefore have widespread consequences. Here, we found that reduced Kdm5c/KDM5C expression is associated with accelerated growth in both human and murine AML cell lines. In vivo, Kdm5c knockdown in a Cebpa mutant AML mouse model resulted in a more aggressive, immature and short-latency phenotype. Mechanistically, we show that knockdown of Kdm5c increased H3K4me3 globally. This translated into the up-regulation of a group of bivalently marked immature genes, resulting in a de-differentiation phenotype which could be reversed by modulating levels of pro-differentiation factors. Finally, we demonstrated that low levels of KDM5C were associated with a decrease in long-term disease-free survival, specifically in female patients. This emphasizes the clinical relevance of our findings and identifies KDM5C as a novel female-biased tumor suppressor in AML.
Project description:Chromatin immunoprecipitation (ChIP) experiments were conducted as previously described (Ito et al, 2013) using anti-H3K4me3 (Millipore, #07-473), anti-H3K4me1 (Abcam, #ab8895), or anti-Kdm5C (Iwase et al., 2016). Hippocampi derived from two different animals were pooled together for each sample and two independent biological replicates per condition were sequenced according to manufacturer instructions in a HiSeq2500 apparatus (Illumina, Inc). Information on library preparation method, size of the libraries, and mapping to reference genome can be found in Supplementary Material accompanying the manuscript. ChIP-seq reads were aligned to the mouse genome (Mus_musculus.GRCm.38.83) using bowtie2 (v2.2.9) (Langmead and Salzberg, 2012) and further processed using samtools (v1.3.1) (Li et al., 2009). Peak calling was performed using MACS2 (v2.1.0) (Zhang et al., 2008) with default parameters except for Kdm5c that were as follows: -q 0.01 --nomodel --extsize 131 --broad --broad-cutoff 0.1. Read counts on aligned bam files were performed using Rsubread (v1.22.3) (Liao et al., 2014). Differential peak methylation analysis for H3K4me3 chromatin mark was performed using DESeq2 (v1.10.0) (Love et al., 2014) of the bioconductor suite (Huber et al., 2015) in the R (v3.3) statistical computing platform. For consideration of differentially methylated regions between conditions, we used adjusted p-value < 0.05 as indicated in the manuscript.
Project description:Here, we show that the Kdm5c/Smcx member of the Jarid1 family of H3K4 demethylases is recruited to both enhancer and core promoter elements in ES and neuronal progenitor cells (NPC). Knockdown of Kdm5c deregulates transcription via a local increase in H3K4me3. While at core promoters the function of Kdm5c is to restrict transcription, loss of Kdm5c impairs enhancer function. Remarkably, an impaired enhancer function activates promoter activity from Kdm5c-bound intergenic regions. Our results demonstrate that the Kdm5c demethylase plays a crucial role in the functional identity and discrimination of enhancers and core promoters. We speculate that this is related to recruitment of H3K4me3 binders like the TFIID and NURF complexes6-8. Providing functional identity to genomic regions through balancing enzymes that deposit and remove histone modifications may prove to be a general epigenetic mechanism for the functional indexing of eukaryotic genomes.