Project description:Here we describe that lysine-specific demethylase 1 (Lsd1/KDM1a), which demethylates histone H3 on LysM-bM-^@M-^I4 or LysM-bM-^@M-^I9 (H3K4/K9), is an indispensible epigenetic governor of hematopoietic differentiation. Integrative genomic analysis in primary hematopoietic cells, combining global occupancy of Lsd1, genome-wide analysis of its histone substrates H3K4 mono- and di-methylation and gene expression profiling, reveals that Lsd1 represses hematopoietic stem and progenitor cell (HSPC) gene expression programs during hematopoietic differentiation. We found that Lsd1 function was not restricted to transcription start sites, but is also critical at enhancers. Loss of Lsd1 at these sites was associated with increased H3K4me1 and H3K4me2 methylation levels on HSPC genes and their derepression. Failure to fully silence HSPC genes compromised differentiation of hematopoietic stem cells and mature blood cell lineages. Our data indicate that Lsd1-mediated concurrent repression of enhancer and promoter activity of stem and progenitor cell genes is a pivotal epigenetic mechanism required for proper hematopoietic maturation. To identify direct target genes of Lsd1 in myeloid cells we mapped global occupancy of Lsd1 in 32D granuolocytic progenitor cells and compared H3K4me1/me2/me3 and H3K27ac histone modifications in Lsd1fl/fl (wild type) vs. Lsd1fl/f Mx1Cre (knockout) Gr1dim Mac1 granuolocytic progenitor cells.
Project description:Here we describe that lysine-specific demethylase 1 (Lsd1/KDM1a), which demethylates histone H3 on Lys 4 or Lys 9 (H3K4/K9), is an indispensible epigenetic governor of hematopoietic differentiation. Integrative genomic analysis in primary hematopoietic cells, combining global occupancy of Lsd1, genome-wide analysis of its histone substrates H3K4 mono- and di-methylation and gene expression profiling, reveals that Lsd1 represses hematopoietic stem and progenitor cell (HSPC) gene expression programs during hematopoietic differentiation. We found that Lsd1 function was not restricted to transcription start sites, but is also critical at enhancers. Loss of Lsd1 at these sites was associated with increased H3K4me1 and H3K4me2 methylation levels on HSPC genes and their derepression. Failure to fully silence HSPC genes compromised differentiation of hematopoietic stem cells and mature blood cell lineages. Our data indicate that Lsd1-mediated concurrent repression of enhancer and promoter activity of stem and progenitor cell genes is a pivotal epigenetic mechanism required for proper hematopoietic maturation.
Project description:Analysis of the transcriptional profiles of developing thymocytes has shown that T lineage commitment is associated with loss of stem cell and early progenitor gene signatures and the acquisition of T cell gene signatures. Less well understood are the epigenetic alterations that accompany or enable these transcriptional changes. Here, we show that the histone demethylase Lsd1 (Kdm1a) performs a key role in extinguishing stem/progenitor transcriptional programs in addition to key repressive gene programs during thymocyte maturation. Deletion of Lsd1 caused a block in late T cell development and resulted in overexpression of interferon response genes as well as genes regulated by the Gfi1, Bcl6, and, most prominently, Bcl11b transcriptional repressors in CD4+CD8+ thymocytes. Transcriptional overexpression in Lsd1-deficient thymocytes was not always associated with increased H3K4 trimethylation at gene promoters, indicating that Lsd1 indirectly affects the expression of many genes. Together, these results identify a critical function for Lsd1 in the epigenetic regulation of multiple repressive gene signatures during T cell development.
Project description:Although there are plenty of researches about nucleic acid in small extracellular vesicles (sEVs), properties of proteins identified as sEVs’ cargos and the mechanism of their action in recipient cell are poorly understood. Here, we show that lysine specific demethylase 1 (LSD1), the first identified histone demethylase in 2004, existed in the cell cultured medium of gastric cancer cells. Further investigation confirmed the presence of LSD1 in sEVs from gastric cancer cells and gastric cancer patient plasma, which is the first identified histone demethylase in sEVs. By shuttling from donor cells to recipient gastric cancer cells, sEVs-delivered LSD1 promoted the cancer cell stemness by positively regulating the expression of Nanog, OCT4, SOX2 and CD44, and suppressed the oxaliplatin response of the recipient cells in vitro and in vivo, while LSD1 depleted sEVs failed to suppress the oxaliplatin response. Collectively, our findings give an evidence for LSD1 as a sEVs protein to promote stemness and suppress oxaliplatin response for the first time and constitute a future avenue to predict oxaliplatin response in gastric cancer clinically.
Project description:Although there are plenty of researches about nucleic acid in small extracellular vesicles (sEVs), properties of proteins identified as sEVs’ cargos and the mechanism of their action in recipient cell are poorly understood. Here, we show that lysine specific demethylase 1 (LSD1), the first identified histone demethylase in 2004, existed in the cell cultured medium of gastric cancer cells. Further investigation confirmed the presence of LSD1 in sEVs from gastric cancer cells and gastric cancer patient plasma, which is the first identified histone demethylase in sEVs. By shuttling from donor cells to recipient gastric cancer cells, sEVs-delivered LSD1 promoted the cancer cell stemness by positively regulating the expression of Nanog, OCT4, SOX2 and CD44, and suppressed the oxaliplatin response of the recipient cells in vitro and in vivo, while LSD1 depleted sEVs failed to suppress the oxaliplatin response. Collectively, our findings give an evidence for LSD1 as a sEVs protein to promote stemness and suppress oxaliplatin response for the first time and constitute a future avenue to predict oxaliplatin response in gastric cancer clinically.
Project description:INCB059872 is a selective irreversible inhibitor of Lysine-Specific Demethylase 1 (LSD1) that is in phase 1 clinical trials in hematopoietic malignancies. Mice treated with INCB059872 had reduced platelet counts within 4 days of treatment. Here, we used single-cell RNA-seq to study the effects of INCB059872 on hematopoietic progenitor populations within wild-type murine bone marrow. Our results showed that INCB059872 triggered accumulation of megakaryocyte early progenitor cells with gene expression hallmarks of stem cells, which may begin to explain the thrombocytopenia observed in patients treated with LSD1 inhibitors.
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.