Project description:Biochemical crosstalk between two or more histone modifications is often observed in epigenetic enzyme regulation but its functional significance in cells has been difficult to discern. Prior enzymatic studies have revealed that Lys14 acetylation of histone H3 can inhibit Lys4 demethylation by lysine specific demethylase 1 (LSD1). Here we have engineered a mutant form of LSD1, Y391K, which renders the nucleosome demethylase activity of LSD1 insensitive to Lys14 acetylation. Y391K LSD1 knockin cells show increased repression of a set of genes associated with cellular adhesion. Chromatin profiling revealed that the cis-regulatory regions of these silenced genes display a higher level of H3 Lys14 acetylation than the baseline in unedited, parental cells. Y391K LSD1 knockin cells show diminished H3 mono-methyl Lys4 in the vicinity of these silenced genes, consistent with a role for enhanced LSD1 demethylase activity in these regions. These findings illuminate the functional consequences of disconnecting histone modification crosstalk for a key epigenetic enzyme in gene and chromatin regulation.
Project description:Biochemical crosstalk between two or more histone modifications is often observed in epigenetic enzyme regulation but its functional significance in cells has been difficult to discern. Prior enzymatic studies have revealed that Lys14 acetylation of histone H3 can inhibit Lys4 demethylation by lysine specific demethylase 1 (LSD1). Here we have engineered a mutant form of LSD1, Y391K, which renders the nucleosome demethylase activity of LSD1 insensitive to Lys14 acetylation. Y391K LSD1 knockin cells show increased repression of a set of genes associated with cellular adhesion. Chromatin profiling revealed that the cis-regulatory regions of these silenced genes display a higher level of H3 Lys14 acetylation than the baseline in unedited, parental cells. Y391K LSD1 knockin cells show diminished H3 mono-methyl Lys4 in the vicinity of these silenced genes, consistent with a role for enhanced LSD1 demethylase activity in these regions. These findings illuminate the functional consequences of disconnecting histone modification crosstalk for a key epigenetic enzyme in gene and chromatin regulation.
Project description:Innate responses to coronavirus are highly cell-specific and remain to date incompletely understood. Tissue-resident macrophages, which are infected by SARS-CoV2 in patients but inconsistently in vitro, exert critical but conflicting effects by secreting both anti-viral type I Interferons and tissue-damaging inflammatory cytokines. Steroids, the only class of host-targeting drugs approved for Covid19, indiscriminately suppress both responses, possibly impairing viral clearance. Here we set up in vitro culture systems with the prototypical murine coronavirus MHV that allow to separately investigate cell-intrinsic and -extrinsic proinflammatory and antiviral activities. We then studied the role of the lysine-demethylase LSD1, previously implicated in innate responses in cancer. We show that the NF-κB-dependent inflammatory response is selectively inhibited by ablating LSD1 with negligible impact on antiviral interferon response. LSD1 ablation additionally unleashed an interferon-independent antiviral response and blocked viral egress through the lysosomal pathway. A cell-intrinsic antiviral and anti-inflammatory activity of LSD1 inhibition was confirmed on in vitro and a recently developed aerosolized in vivo model of human SARS-COV2 infection. These results show that LSD1 controls innate responses against coronaviruses at multiple levels and provide a mechanistic rationale for repurposing LSD1 inhibitors, a class of drugs extensively studied in oncology, for Covid-19 treatment.
Project description:This SuperSeries is composed of the following subset Series: GSE34672: Inhibition of the LSD1 (KDM1A) demethylase reactivates the all-trans-retinoic acid differentiation pathway in acute myeloid leukemia [Illumina HumanHT-12 gene expression array] GSE34725: Inhibition of the LSD1 (KDM1A) demethylase reactivates the all-trans-retinoic acid differentiation pathway in acute myeloid leukemia [ChIP-Seq] Refer to individual Series
Project description:We report the identification of LSD1 binding genomic regions in mouse embryonic stem cells (ESC) by high throughput sequencing. By obtaining over 10 million 36 bp reads of sequence from each chromatin immunoprecipitated DNA, we generated genome-wide maps for LSD1 and histone H3 dimethylated on lysine 4 (H3K4me2), the substrate for LSD1 in mouse ESCs. Our results showed an extensive overlap between the LSD1 and H3K4me2 genomic regions and a correlation between the genomic levels of LSD1/H3K4me2 and gene expression, including many highly expressed ESC genes. LSD1 is recruited to the chromatin of cells in the G1/S/G2 phases and is displaced from the chromatin of M phase cells, suggesting that LSD1 or H3K4me2 alternatively occupies LSD1 genomic regions during cell cycle progression. LSD1 knockdown by RNA interference or its displacement from the chromatin by anti-neoplastic agents caused an increase in the levels of a subset of LSD1 target genes. Taken together, these results suggest that cell-cycle dependent association and dissociation of LSD1 with chromatin mediates short-time scale gene expression changes during ES cell cycle progression. Examination of LSD1 and lysine 4 dimethylated histone H3 (H3K4me2) binding genomic regions in embryonic stem cells. Input genomic DNA and DNA immunoprecipitaed with control IgG was included as controls.
Project description:Metazoan enhancers are decorated by mono-methylation (me1) of the lysine 4 residue on histone H3 (H3K4), a mark deposited by methyltransferases MLL3/MLL4 and removed by the lysine-specific histone demethylase 1A (LSD1 or KDM1A) via its flavin adenine dinucleotide (FAD)-dependent amine oxidase activity. As a component of histone deacetylases HDAC1/2-containing complex CoREST, LSD1 is required for animal development, and is implicated in Kabuki Syndrome-like congenital diseases and multiple types of cancer. Although prior research has investigated the demethylase function of LSD1 extensively, the mechanisms underlying LSD1’s role in development and diseases remain enigmatic. Here, we have utilized genetic, epigenetic, genomic, and cell biology approaches to dissect the role of LSD1 and its demethylase activity in gene regulation and cell fate transition. Surprisingly, the catalytic inactivation of LSD1 only has a mild impact on gene expression whereas the loss of LSD1 protein de-represses enhancers globally. Moreover, LSD1 deletion, rather than its catalytic inactivation, causes defects in spontaneous differentiation, the transition from naive to primed pluripotency, embryoid body formation, and cardiomyocyte differentiation. Interestingly, deletion of LSD1 increases H3K27ac levels and binding of P300 to LSD1-targeted enhancers. We further show that the gain in the level of H3K27ac catalyzed by P300/CBP, not the loss of CoREST complex components from chromatin, contributes to the transcription de-repression of LSD1 targets and differentiation defects caused by LSD1 loss. Taken together, our study demonstrates a demethylase-independent role of LSD1 in regulating enhancers and cell fate transition, providing insight into the treatment of diseases driven by LSD1 mutations and misregulation.
Project description:Metazoan enhancers are decorated by mono-methylation (me1) of the lysine 4 residue on histone H3 (H3K4), a mark deposited by methyltransferases MLL3/MLL4 and removed by the lysine-specific histone demethylase 1A (LSD1 or KDM1A) via its flavin adenine dinucleotide (FAD)-dependent amine oxidase activity. As a component of histone deacetylases HDAC1/2-containing complex CoREST, LSD1 is required for animal development, and is implicated in Kabuki Syndrome-like congenital diseases and multiple types of cancer. Although prior research has investigated the demethylase function of LSD1 extensively, the mechanisms underlying LSD1’s role in development and diseases remain enigmatic. Here, we have utilized genetic, epigenetic, genomic, and cell biology approaches to dissect the role of LSD1 and its demethylase activity in gene regulation and cell fate transition. Surprisingly, the catalytic inactivation of LSD1 only has a mild impact on gene expression whereas the loss of LSD1 protein de-represses enhancers globally. Moreover, LSD1 deletion, rather than its catalytic inactivation, causes defects in spontaneous differentiation, the transition from naive to primed pluripotency, embryoid body formation, and cardiomyocyte differentiation. Interestingly, deletion of LSD1 increases H3K27ac levels and binding of P300 to LSD1-targeted enhancers. We further show that the gain in the level of H3K27ac catalyzed by P300/CBP, not the loss of CoREST complex components from chromatin, contributes to the transcription de-repression of LSD1 targets and differentiation defects caused by LSD1 loss. Taken together, our study demonstrates a demethylase-independent role of LSD1 in regulating enhancers and cell fate transition, providing insight into the treatment of diseases driven by LSD1 mutations and misregulation.
Project description:Metazoan enhancers are decorated by mono-methylation (me1) of the lysine 4 residue on histone H3 (H3K4), a mark deposited by methyltransferases MLL3/MLL4 and removed by the lysine-specific histone demethylase 1A (LSD1 or KDM1A) via its flavin adenine dinucleotide (FAD)-dependent amine oxidase activity. As a component of histone deacetylases HDAC1/2-containing complex CoREST, LSD1 is required for animal development, and is implicated in Kabuki Syndrome-like congenital diseases and multiple types of cancer. Although prior research has investigated the demethylase function of LSD1 extensively, the mechanisms underlying LSD1’s role in development and diseases remain enigmatic. Here, we have utilized genetic, epigenetic, genomic, and cell biology approaches to dissect the role of LSD1 and its demethylase activity in gene regulation and cell fate transition. Surprisingly, the catalytic inactivation of LSD1 only has a mild impact on gene expression whereas the loss of LSD1 protein de-represses enhancers globally. Moreover, LSD1 deletion, rather than its catalytic inactivation, causes defects in spontaneous differentiation, the transition from naive to primed pluripotency, embryoid body formation, and cardiomyocyte differentiation. Interestingly, deletion of LSD1 increases H3K27ac levels and binding of P300 to LSD1-targeted enhancers. We further show that the gain in the level of H3K27ac catalyzed by P300/CBP, not the loss of CoREST complex components from chromatin, contributes to the transcription de-repression of LSD1 targets and differentiation defects caused by LSD1 loss. Taken together, our study demonstrates a demethylase-independent role of LSD1 in regulating enhancers and cell fate transition, providing insight into the treatment of diseases driven by LSD1 mutations and misregulation.