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:Precise control of transcriptional programs underlying metazoan development is modulated by enzymatically active co-regulatory complexes, coupled with epigenetic strategies, but how specific members of histone modification enzyme families such as histone methyltransferases and demethylases are utilized in vivo to simultaneously orchestrate distinct developmental gene activation and repression programs remains unclear. Here, we report that the initially-described histone lysine demethylase, LSD1, a component of the CoREST/CtBP corepressor complex, is required for late cell-lineage determination and differentiation during pituitary organogenesis. Surprisingly, LSD1 acts primarily on target gene activation programs, as well as in gene repression programs, based on recruitment of distinct LSD1-containing coactivator or corepressor complexes. Intriguingly, LSD1-dependent gene repression programs can be extended late in development with the induced expression of ZEB1, a Kr.pple-like repressor that can act as a molecular beacon for recruitment of the LSD1-containing CtBP/CoREST corepressor complex, causing repression of an additional cohort of genes, such as GH, that previously required LSD1 for activation.
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:Lysine-specific demethylase 1 (LSD1) is involved in gene regulation and development; however, its precise function, molecular targets and underlying mechanisms during development are poorly understood. Here, we show that LSD1 is required for neuronal progenitor cell (NPC) maintenance during cortical development. A ChIP-seq analysis identified a LSD1 binding site (LBAL) downstream of Atrophin1 (ATN1). Surprisingly, tranylcypromine (LSD1 inhibitor) treatment increased H3K4 methylation at LBAL, leading to ATN1 repression and NPC differentiation. Knockdown of LSD1 and ATN1 phenocopied each other in inducing NPC premature differentiation and depletion which could be rescued by ATN1 overexpression, suggesting that LSD1 controls NPC differentiation via regulation of ATN1 methylation status and expression. The involvement of LSD1 in ATN1 expression and NPC maintenance were confirmed in knockout mice. These findings hint at the potential application for the clinical drug, tranylcypromine, in the prevention and/or treatment of ATN1-associated degenerative disease, dentatorubral-pallidoluysian atrophy. Examination of LSD1 binding sites in neuronal progenitor cells.
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:During brain development, histone-modifying enzymes play an important role by orchestrating transcriptional programs that regulate neuronal maturation. Lysine-Specific Demethylase 1 (LSD1, also named as KDM1A) functions as a transcriptional repressor by removing methyl groups at lysine 4 of histone H3 (H3K4). In neurons, alternative splicing can include an additional exon (exon E8a) within LSD1 transcripts, generating a LSD1+8a neuro-specific isoform. We here report that LSD1+8a isoform does not have the intrinsic ability to demethylate H3K4. LSD1+8a functions as a co-activator on its target genes by removing H3K9 repressive histone marks. We identify the supervillin protein (SVIL) as a LSD1+8a interacting partner and demonstrate that SVIL protein regulates neuronal maturation by controlling LSD1+8a mediated H3K9 demethylation. Thus, our results show that alternative splicing provides a genius mechanism by which LSD1 isoforms can acquire a dual specificity (H3K9 vs H3K4) and therefore differentially control specific gene expression patterns during brain development. In order to find some LSD1+8a regulated genes at differentiated SH-SY5Y cell lines, we infected SH-SY5Y with control or LSD1+8a shRNA, then induced differentiation with RA and BDNF, (Retinoic acid (RA) (Sigma) was added at a final concentration of 10 μM the next day after plating. After 4 days, the cells were washed three times with PBS and incubated with 50 ng/mL of Brain Derived Neural Factor (BDNF) (Millipore) in serum-free medium for 3 days), we extracted RNA from BDNF induced SH-SY5Y cells for expression analysis.Duplicates were included for Affymetrix Human transcriptome version 2 array.