RESUMO
MLL/KMT2A amplifications and translocations are prevalent in infant, adult, and therapy-induced leukemia. However, the molecular contributor(s) to these alterations are unclear. Here, we demonstrate that histone H3 lysine 9 mono- and di-methylation (H3K9me1/2) balance at the MLL/KMT2A locus regulates these amplifications and rearrangements. This balance is controlled by the crosstalk between lysine demethylase KDM3B and methyltransferase G9a/EHMT2. KDM3B depletion increases H3K9me1/2 levels and reduces CTCF occupancy at the MLL/KMT2A locus, in turn promoting amplification and rearrangements. Depleting CTCF is also sufficient to generate these focal alterations. Furthermore, the chemotherapy doxorubicin (Dox), which associates with therapy-induced leukemia and promotes MLL/KMT2A amplifications and rearrangements, suppresses KDM3B and CTCF protein levels. KDM3B and CTCF overexpression rescues Dox-induced MLL/KMT2A alterations. G9a inhibition in human cells or mice also suppresses MLL/KMT2A events accompanying Dox treatment. Therefore, MLL/KMT2A amplifications and rearrangements are controlled by epigenetic regulators that are tractable drug targets, which has clinical implications.
Assuntos
Epigênese Genética , Proteína de Leucina Linfoide-Mieloide , Adulto , Animais , Humanos , Lactente , Camundongos , Doxorrubicina/farmacologia , Rearranjo Gênico , Antígenos de Histocompatibilidade , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Leucemia/metabolismo , Lisina/metabolismo , Proteína de Leucina Linfoide-Mieloide/genética , Translocação GenéticaRESUMO
Acquired chromosomal DNA amplifications are features of many tumors. Although overexpression and stabilization of the histone H3 lysine 9/36 (H3K9/36) tri-demethylase KDM4A generates transient site-specific copy number gains (TSSGs), additional mechanisms directly controlling site-specific DNA copy gains are not well defined. In this study, we uncover a collection of H3K4-modifying chromatin regulators that function with H3K9 and H3K36 regulators to orchestrate TSSGs. Specifically, the H3K4 tri-demethylase KDM5A and specific COMPASS/KMT2 H3K4 methyltransferases modulate different TSSG loci through H3K4 methylation states and KDM4A recruitment. Furthermore, a distinct chromatin modifier network, MLL1-KDM4B-KDM5B, controls copy number regulation at a specific genomic locus in a KDM4A-independent manner. These pathways comprise an epigenetic addressing system for defining site-specific DNA rereplication and amplifications.
Assuntos
Cromatina/metabolismo , Variações do Número de Cópias de DNA , Metilação de DNA , Histonas/metabolismo , Lisina/metabolismo , Proteína 2 de Ligação ao Retinoblastoma/metabolismo , Ciclo Celular , Células HEK293 , Humanos , Proteína 2 de Ligação ao Retinoblastoma/genéticaRESUMO
Developing strategies to activate tumor-cell-intrinsic immune response is critical for improving tumor immunotherapy by exploiting tumor vulnerability. KDM4A, as a histone H3 lysine 9 trimethylation (H3K9me3) demethylase, has been found to play a critical role in squamous cell carcinoma (SCC) growth and metastasis. Here we report that KDM4A inhibition promoted heterochromatin compaction and induced DNA replication stress, which elicited antitumor immunity in SCC. Mechanistically, KDM4A inhibition promoted the formation of liquid-like HP1γ puncta on heterochromatin and stall DNA replication, which activated tumor-cell-intrinsic cGAS-STING signaling through replication-stress-induced cytosolic DNA accumulation. Moreover, KDM4A inhibition collaborated with PD1 blockade to inhibit SCC growth and metastasis by recruiting and activating CD8+ T cells. In vivo lineage tracing demonstrated that KDM4A inhibition plus PD1 blockade efficiently eliminated cancer stem cells. Altogether, our results demonstrate that targeting KDM4A can activate anti-tumor immunity and enable PD1 blockade immunotherapy by aggravating replication stress in SCC cells.
Assuntos
Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/imunologia , Replicação do DNA/genética , Epigênese Genética , Histona Desmetilases/metabolismo , Imunidade/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Estresse Fisiológico/genética , Animais , Linfócitos T CD8-Positivos/imunologia , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Quimiocinas/metabolismo , Homólogo 5 da Proteína Cromobox , Proteínas Cromossômicas não Histona/metabolismo , Dano ao DNA/genética , Células Epiteliais/metabolismo , Deleção de Genes , Humanos , Metástase Linfática , Camundongos Transgênicos , Invasividade Neoplásica , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Receptor de Morte Celular Programada 1/metabolismo , Receptores CXCR3/metabolismo , Células Th1/imunologiaRESUMO
In mammals, the transition from mitosis to meiosis facilitates the successful production of gametes. However, the regulatory mechanisms that control meiotic initiation remain unclear, particularly in the context of complex histone modifications. Herein, we show that KDM2A, acting as a lysine demethylase targeting H3K36me3 in male germ cells, plays an essential role in modulating meiotic entry and progression. Conditional deletion of Kdm2a in mouse pre-meiotic germ cells results in complete male sterility, with spermatogenesis ultimately arrested at the zygotene stage of meiosis. KDM2A deficiency disrupts H3K36me2/3 deposition in c-KIT+ germ cells, characterized by a reduction in H3K36me2 but a dramatic increase in H3K36me3. Furthermore, KDM2A recruits the transcription factor E2F1 and its co-factor HCFC1 to the promoters of key genes required for meiosis entry and progression, such as Stra8, Meiosin, Spo11, and Sycp1. Collectively, our study unveils an essential role for KDM2A in mediating H3K36me2/3 deposition and controlling the programmed gene expression necessary for the transition from mitosis to meiosis during spermatogenesis.
RESUMO
Dermal Fibroblast Progenitors (DFPs) differentiate into distinct fibroblast lineages during skin development. However, the epigenetic mechanisms that regulate DFP differentiation are not known. Our objective was to use multimodal single-cell approaches, epigenetic assays, and allografting techniques to define a DFP state and the mechanism that governs its differentiation potential. Our initial results indicated that the overall transcription profile of DFPs is repressed by H3K27me3 and has inaccessible chromatin at lineage-specific genes. Surprisingly, the repressive chromatin profile of DFPs renders them unable to reform the skin in allograft assays despite their multipotent potential. We hypothesized that chromatin derepression was modulated by the H3K27me3 demethylase, Kdm6b/Jmjd3. Dermal fibroblast-specific deletion of Kdm6b/Jmjd3 in mice resulted in adipocyte compartment ablation and inhibition of mature dermal papilla functions, confirmed by additional single-cell RNA-seq, ChIP-seq, and allografting assays. We conclude that DFPs are functionally derepressed during murine skin development by Kdm6b/Jmjd3. Our studies therefore reveal a multimodal understanding of how DFPs differentiate into distinct fibroblast lineages and provide a novel publicly available multiomics search tool.
Assuntos
Cromatina , Histonas , Animais , Camundongos , Cromatina/genética , Histonas/genética , Histonas/metabolismo , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Diferenciação Celular/genética , Desmetilação , Fibroblastos/metabolismoRESUMO
Hypoxia, which occurs during tumor growth, triggers complex adaptive responses in which peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) plays a critical role in mitochondrial biogenesis and oxidative metabolism. However, how PGC-1α is regulated in response to oxygen availability remains unclear. We demonstrated that lysine demethylase 3A (KDM3A) binds to PGC-1α and demethylates monomethylated lysine (K) 224 of PGC-1α under normoxic conditions. Hypoxic stimulation inhibits KDM3A, which has a high KM of oxygen for its activity, and enhances PGC-1α K224 monomethylation. This modification decreases PGC-1α's activity required for NRF1- and NRF2-dependent transcriptional regulation of TFAM, TFB1M, and TFB2M, resulting in reduced mitochondrial biogenesis. Expression of PGC-1α K224R mutant significantly increases mitochondrial biogenesis, reactive oxygen species (ROS) production, and tumor cell apoptosis under hypoxia and inhibits brain tumor growth in mice. This study revealed that PGC-1α monomethylation, which is dependent on oxygen availability-regulated KDM3A, plays a critical role in the regulation of mitochondrial biogenesis.
Assuntos
Neoplasias Encefálicas/enzimologia , Histona Desmetilases com o Domínio Jumonji/metabolismo , Mitocôndrias/enzimologia , Biogênese de Organelas , Oxigênio/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Processamento de Proteína Pós-Traducional , Animais , Apoptose , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Células HeLa , Células Hep G2 , Humanos , Histona Desmetilases com o Domínio Jumonji/genética , Metilação , Camundongos Endogâmicos BALB C , Camundongos Nus , Mitocôndrias/patologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Carga Tumoral , Hipóxia Tumoral , Microambiente TumoralRESUMO
Alternative pre-mRNA-splicing-induced post-transcriptional gene expression regulation is one of the pathways for tumors maintaining proliferation rates accompanying the malignant phenotype under stress. Here, we uncover a list of hyperacetylated proteins in the context of acutely reduced Acetyl-CoA levels under nutrient starvation. PHF5A, a component of U2 snRNPs, can be acetylated at lysine 29 in response to multiple cellular stresses, which is dependent on p300. PHF5A acetylation strengthens the interaction among U2 snRNPs and affects global pre-mRNA splicing pattern and extensive gene expression. PHF5A hyperacetylation-induced alternative splicing stabilizes KDM3A mRNA and promotes its protein expression. Pathologically, PHF5A K29 hyperacetylation and KDM3A upregulation axis are correlated with poor prognosis of colon cancer. Our findings uncover a mechanism of an anti-stress pathway through which acetylation on PHF5A promotes the cancer cells' capacity for stress resistance and consequently contributes to colon carcinogenesis.
Assuntos
Processamento Alternativo , Carcinogênese/genética , Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Histona Desmetilases com o Domínio Jumonji/genética , Proteínas de Ligação a RNA/genética , Transativadores/genética , Acetilcoenzima A/deficiência , Acetilação , Animais , Carcinogênese/metabolismo , Carcinogênese/patologia , Movimento Celular , Proliferação de Células , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Células HCT116 , Humanos , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Histona Desmetilases com o Domínio Jumonji/metabolismo , Células MCF-7 , Masculino , Camundongos , Camundongos Nus , Prognóstico , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/antagonistas & inibidores , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteína Nuclear Pequena U2/genética , Ribonucleoproteína Nuclear Pequena U2/metabolismo , Transdução de Sinais , Análise de Sobrevida , Transativadores/antagonistas & inibidores , Transativadores/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Fatores de Transcrição de p300-CBP/genética , Fatores de Transcrição de p300-CBP/metabolismoRESUMO
More than 90% of small cell lung cancers (SCLCs) harbor loss-of-function mutations in the tumor suppressor gene RB1 The canonical function of the RB1 gene product, pRB, is to repress the E2F transcription factor family, but pRB also functions to regulate cellular differentiation in part through its binding to the histone demethylase KDM5A (also known as RBP2 or JARID1A). We show that KDM5A promotes SCLC proliferation and SCLC's neuroendocrine differentiation phenotype in part by sustaining expression of the neuroendocrine transcription factor ASCL1. Mechanistically, we found that KDM5A sustains ASCL1 levels and neuroendocrine differentiation by repressing NOTCH2 and NOTCH target genes. To test the role of KDM5A in SCLC tumorigenesis in vivo, we developed a CRISPR/Cas9-based mouse model of SCLC by delivering an adenovirus (or an adeno-associated virus [AAV]) that expresses Cre recombinase and sgRNAs targeting Rb1, Tp53, and Rbl2 into the lungs of Lox-Stop-Lox Cas9 mice. Coinclusion of a KDM5A sgRNA decreased SCLC tumorigenesis and metastasis, and the SCLCs that formed despite the absence of KDM5A had higher NOTCH activity compared to KDM5A+/+ SCLCs. This work establishes a role for KDM5A in SCLC tumorigenesis and suggests that KDM5 inhibitors should be explored as treatments for SCLC.
Assuntos
Diferenciação Celular/genética , Células Neuroendócrinas/citologia , Receptores Notch/fisiologia , Proteína 2 de Ligação ao Retinoblastoma/metabolismo , Transdução de Sinais/genética , Carcinoma de Pequenas Células do Pulmão/enzimologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Linhagem Celular , Transformação Celular Neoplásica/genética , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/genética , Histona Desmetilases/metabolismo , Humanos , Técnicas In Vitro , Camundongos , Células Neuroendócrinas/patologia , Carcinoma de Pequenas Células do Pulmão/fisiopatologiaRESUMO
De novo variants are a leading cause of neurodevelopmental disorders (NDDs), but because every monogenic NDD is different and usually extremely rare, it remains a major challenge to understand the complete phenotype and genotype spectrum of any morbid gene. According to OMIM, heterozygous variants in KDM6B cause "neurodevelopmental disorder with coarse facies and mild distal skeletal abnormalities." Here, by examining the molecular and clinical spectrum of 85 reported individuals with mostly de novo (likely) pathogenic KDM6B variants, we demonstrate that this description is inaccurate and potentially misleading. Cognitive deficits are seen consistently in all individuals, but the overall phenotype is highly variable. Notably, coarse facies and distal skeletal anomalies, as defined by OMIM, are rare in this expanded cohort while other features are unexpectedly common (e.g., hypotonia, psychosis, etc.). Using 3D protein structure analysis and an innovative dual Drosophila gain-of-function assay, we demonstrated a disruptive effect of 11 missense/in-frame indels located in or near the enzymatic JmJC or Zn-containing domain of KDM6B. Consistent with the role of KDM6B in human cognition, we demonstrated a role for the Drosophila KDM6B ortholog in memory and behavior. Taken together, we accurately define the broad clinical spectrum of the KDM6B-related NDD, introduce an innovative functional testing paradigm for the assessment of KDM6B variants, and demonstrate a conserved role for KDM6B in cognition and behavior. Our study demonstrates the critical importance of international collaboration, sharing of clinical data, and rigorous functional analysis of genetic variants to ensure correct disease diagnosis for rare disorders.
Assuntos
Deficiência Intelectual , Transtornos do Neurodesenvolvimento , Humanos , Animais , Fácies , Transtornos do Neurodesenvolvimento/genética , Transtornos do Neurodesenvolvimento/patologia , Fenótipo , Drosophila , Deficiência Intelectual/patologia , Histona Desmetilases com o Domínio Jumonji/genéticaRESUMO
Histone-modifying proteins play important roles in the precise regulation of the transcriptional programs that coordinate development. KDM5 family proteins interact with chromatin through demethylation of H3K4me3 as well as demethylase-independent mechanisms that remain less understood. To gain fundamental insights into the transcriptional activities of KDM5 proteins, we examined the essential roles of the single Drosophila Kdm5 ortholog during development. KDM5 performs crucial functions in the larval neuroendocrine prothoracic gland, providing a model to study its role in regulating key gene expression programs. Integrating genome binding and transcriptomic data, we identify that KDM5 regulates the expression of genes required for the function and maintenance of mitochondria, and we find that loss of KDM5 causes morphological changes to mitochondria. This is key to the developmental functions of KDM5, as expression of the mitochondrial biogenesis transcription factor Ets97D, homolog of GABPα, is able to suppress the altered mitochondrial morphology as well as the lethality of Kdm5 null animals. Together, these data establish KDM5-mediated cellular functions that are important for normal development and could contribute to KDM5-linked disorders when dysregulated.
Assuntos
Proteínas de Drosophila , Drosophila , Animais , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Histona Desmetilases/metabolismo , Cromatina , BiologiaRESUMO
The histone lysine demethylase KDM5B is frequently up-regulated in various human cancer cells. However, its expression and functional role in human acute myeloid leukemia (AML) cells remain unclear. Here, we found that the expression level of KDM5B is high in primary human AML cells. We have demonstrated that knocking down KDM5B leads to apoptosis and impairs proliferation in primary human AML and some human AML cell lines. We further identified miR-140-3p as a downstream target gene of KDM5B. KDM5B expression was inversely correlated with the miR-140-3p level in primary human AML cells. Molecular studies showed that silencing KDM5B enhanced H3K4 trimethylation (H3K4me3) at the promoter of miR-140-3p, leading to high expression of miR-140-3p, which in turn inhibited B-cell CLL/lymphoma 2 (BCL2) expression. Finally, we demonstrate that the defective proliferation induced by KDM5B knockdown (KD) can be rescued with the miR-140-3p inhibitor or enhanced by combining KDM5B KD with a BCL2 inhibitor. Altogether, our data support the conclusion that KDM5B promotes tumorigenesis in human AML cells through the miR-140-3p/BCL2 axis. Targeting the KDM5B/miR-140-3p/BCL2 pathway may hold therapeutic promise for treating human AML.
Assuntos
Leucemia Mieloide Aguda , MicroRNAs , Humanos , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Leucemia Mieloide Aguda/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Repressoras/genéticaRESUMO
Nuclear receptors induce both transcriptional activation and repression programs responsible for development, homeostasis, and disease. Here, we report a previously overlooked enhancer decommissioning strategy underlying a large estrogen receptor alpha (ERα)-dependent transcriptional repression program. The unexpected signature for this E2-induced program resides in indirect recruitment of ERα to a large cohort of pioneer factor basally active FOXA1-bound enhancers that lack cognate ERα DNA-binding elements. Surprisingly, these basally active estrogen-repressed (BAER) enhancers are decommissioned by ERα-dependent recruitment of the histone demethylase KDM2A, functioning independently of its demethylase activity. Rather, KDM2A tethers the E3 ubiquitin-protein ligase NEDD4 to ubiquitylate/dismiss Pol II to abrogate eRNA transcription, with consequent target gene downregulation. Thus, our data reveal that Pol II ubiquitylation/dismissal may serve as a potentially broad strategy utilized by indirectly bound nuclear receptors to abrogate large programs of pioneer factor-mediated, eRNA-producing enhancers.
Assuntos
Elementos Facilitadores Genéticos , Receptor alfa de Estrogênio/genética , Proteínas F-Box/genética , Fator 3-alfa Nuclear de Hepatócito/genética , Histona Desmetilases com o Domínio Jumonji/genética , Ubiquitina-Proteína Ligases Nedd4/genética , RNA Polimerase II/genética , Sequência de Bases , Sítios de Ligação , Sistemas CRISPR-Cas , Estradiol/farmacologia , Receptor alfa de Estrogênio/metabolismo , Proteínas F-Box/metabolismo , Edição de Genes/métodos , Regulação da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/metabolismo , Células MCF-7 , Ubiquitina-Proteína Ligases Nedd4/metabolismo , Ligação Proteica , RNA/genética , RNA/metabolismo , RNA Polimerase II/metabolismo , Transdução de Sinais , Transcrição Gênica/efeitos dos fármacos , Ubiquitinação/efeitos dos fármacosRESUMO
The histone lysine demethylase KDM5B is implicated in recessive intellectual disability disorders, and heterozygous, protein-truncating variants in KDM5B are associated with reduced cognitive function in the population. The KDM5 family of lysine demethylases has developmental and homeostatic functions in the brain, some of which appear to be independent of lysine demethylase activity. To determine the functions of KDM5B in hippocampus-dependent learning and memory, we first studied male and female mice homozygous for a Kdm5b Δ ARID allele that lacks demethylase activity. Kdm5b Δ ARID/ Δ ARID mice exhibited hyperactivity and long-term memory deficits in hippocampus-dependent learning tasks. The expression of immediate early, activity-dependent genes was downregulated in these mice and hyperactivated upon a learning stimulus compared with wild-type (WT) mice. A number of other learning-associated genes were also significantly dysregulated in the Kdm5b Δ ARID/ Δ ARID hippocampus. Next, we knocked down Kdm5b specifically in the adult, WT mouse hippocampus with shRNA. Kdm5b knockdown resulted in spontaneous seizures, hyperactivity, and hippocampus-dependent long-term memory and long-term potentiation deficits. These findings identify KDM5B as a critical regulator of gene expression and synaptic plasticity in the adult hippocampus and suggest that at least some of the cognitive phenotypes associated with KDM5B gene variants are caused by direct effects on memory consolidation mechanisms.
Assuntos
Hipocampo , Deficiência Intelectual , Histona Desmetilases com o Domínio Jumonji , Consolidação da Memória , Memória de Longo Prazo , Animais , Hipocampo/metabolismo , Camundongos , Masculino , Feminino , Deficiência Intelectual/genética , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Consolidação da Memória/fisiologia , Memória de Longo Prazo/fisiologia , Potenciação de Longa Duração/genética , Potenciação de Longa Duração/fisiologia , Camundongos Endogâmicos C57BL , Proteínas de Ligação a DNARESUMO
Machine learning including modern deep learning models has been extensively used in drug design and screening. However, reliable prediction of molecular properties is still challenging when exploring out-of-domain regimes, even for deep neural networks. Therefore, it is important to understand the uncertainty of model predictions, especially when the predictions are used to guide further experiments. In this study, we explored the utility and effectiveness of evidential uncertainty in compound screening. The evidential Graphormer model was proposed for uncertainty-guided discovery of KDM1A/LSD1 inhibitors. The benchmarking results illustrated that (i) Graphormer exhibited comparative predictive power to state-of-the-art models, and (ii) evidential regression enabled well-ranked uncertainty estimates and calibrated predictions. Subsequently, we leveraged time-splitting on the curated KDM1A/LSD1 dataset to simulate out-of-distribution predictions. The retrospective virtual screening showed that the evidential uncertainties helped reduce false positives among the top-acquired compounds and thus enabled higher experimental validation rates. The trained model was then used to virtually screen an independent in-house compound set. The top 50 compounds ranked by two different ranking strategies were experimentally validated, respectively. In general, our study highlighted the importance to understand the uncertainty in prediction, which can be recognized as an interpretable dimension to model predictions.
Assuntos
Histonas , Lisina , Estudos Retrospectivos , Incerteza , Histona Desmetilases/metabolismoRESUMO
Neurogenesis begins with neural stem cells undergoing symmetric proliferative divisions to expand and then switching to asymmetric differentiative divisions to generate neurons in the developing brain. Chromatin regulation plays a critical role in this switch. Histone lysine-specific demethylase LSD1 demethylates H3K4me1/2 and H3K9me1/2 but the mechanisms of its global regulatory functions in human neuronal development remain unclear. We performed genome-wide ChIP-seq of LSD1 occupancy, RNA-seq, and Histone ChIP-seq upon LSD1 inhibition to identify its repressive role in human neural stem cells. Novel downstream effectors of LSD1 were identified, including the Notch signaling pathway genes and human-neural progenitor-enriched extracellular matrix (ECM) pathway/cell adhesion genes, which were upregulated upon LSD1 inhibition. LSD1 inhibition led to decreased neurogenesis, and overexpression of downstream effectors mimicked this effect. Histone ChIP-seq analysis revealed that active and enhancer markers H3K4me2, H3K4me1, and H3K9me1 were upregulated upon LSD1 inhibition, while the repressive H3K9me2 mark remained mostly unchanged. Our work identifies the human-neural progenitor-enriched ECM pathway/cell adhesion genes and Notch signaling pathway genes as novel downstream effectors of LSD1, regulating neuronal differentiation in human neural stem cells.
Assuntos
Histonas , Células-Tronco Neurais , Humanos , Adesão Celular/genética , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Histonas/metabolismo , Células-Tronco Neurais/metabolismo , Neurogênese/genéticaRESUMO
KDM4C is implicated in the regulation of cell proliferation, differentiation, and maintenance in various stem cell types. However, its function in neural stem cells (NSCs) remains poorly understood. Therefore, this study aims to investigate the role and regulatory mechanism of KDM4C in NSCs. Primary hippocampal NSCs were isolated from neonatal mice, and both in vivo and in vitro lentivirus-mediated overexpression of KDM4C were induced in these hippocampal NSCs. Staining results revealed a significant increase in BrdU- and Ki-67-positive cells, along with an elevated number of cells in S phases due to KDM4C overexpression. Subsequently, RNA-seq was employed to analyze gene expression changes following KDM4C upregulation. GO enrichment analysis, KEGG analysis, and GSEA highlighted KDM4C-regulated genes associated with development, cell cycle, and neurogenesis. Protein-protein interaction analysis uncovered that ApoE protein interacts with several genes (top 10 upregulated and downregulated) regulated by KDM4C. Notably, knocking down ApoE mitigated the proliferative effect induced by KDM4C overexpression in NSCs. Our study demonstrates that KDM4C overexpression significantly upregulates ApoE expression, ultimately promoting proliferation in mouse hippocampal NSCs. These findings provide valuable insights into the molecular mechanisms governing neurodevelopment, with potential implications for therapeutic strategies in neurological disorders.
Assuntos
Apolipoproteínas E , Células-Tronco Neurais , Animais , Camundongos , Ciclo Celular , Proliferação de Células , HipocampoRESUMO
Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease among neonates, with increasing morbidity and mortality. This study aims to investigate the effect and mechanism of lysine demethylase 3A (KDM3A) on hyperoxia-induced BPD. Hyperoxia-induced BPD mouse and alveolar epithelial cell models were constructed. The effects of hyperoxia on lung development were evaluated by histological and morphological analysis. The levels of KDM3A, E26 transformation specific-1 (ETS1), H3 lysine 9 dimethylation (H3K9me2), and endoplasmic reticulum (ER) stress-related indexes were quantified by RT-qPCR, Western blot, and IF staining. Cell apoptosis was assessed by flow cytometry and TUNEL staining. Transfection of oe-ETS1, oe-KDM3A, and sh-ETS1 was applied in hyperoxia-induced alveolar epithelial cells to explore the mechanism of the KDM3A/ETS1 axis in hyperoxia-induced apoptosis. KDM3A inhibitor IOX1 was applied to validate the in vivo effect of KDM3A in hyperoxia-induced BPD mice. The results displayed that hyperoxia-induced BPD mice showed reduced body weight, severe destruction of alveolar structure, decreased radial alveolar count (RAC), and increased mean linear intercept (MLI) and mean alveolar diameter (MAD). Further, hyperoxia induction down-regulated ETS1 expression, raised ER stress levels, and increased apoptosis rate in BPD mice and alveolar epithelial cells. However, transfection of oe-ETS1 improved the above changes in hyperoxia-induced alveolar epithelial cells. Moreover, transfection of oe-KDM3A up-regulated ETS1 expression, down-regulated H3K9me2 expression, inhibited ER stress, and reduced apoptosis rate in hyperoxia-induced alveolar epithelial cells. In addition, transfection of sh-ETS1 reversed the inhibitory effect of KDM3A on hyperoxia-induced apoptosis by regulating ER stress. In vivo experiments, KDM3A inhibitor IOX1 intervention further aggravated BPD in newborn mice. In a word, KDM3A alleviated hyperoxia-induced BPD in mice by promoting ETS1 expression.
Assuntos
Displasia Broncopulmonar , Hiperóxia , Animais , Camundongos , Animais Recém-Nascidos , Displasia Broncopulmonar/genética , Displasia Broncopulmonar/metabolismo , Modelos Animais de Doenças , Hiperóxia/complicações , Hiperóxia/metabolismo , Hiperóxia/patologia , Pulmão/metabolismo , Lisina/metabolismo , Fatores de Transcrição/metabolismoRESUMO
The compound 2-4(4-methylphenyl)-1,2-benzisothiazol-3(2H)-one (PBIT) is an inhibitor of the KDM5 family of lysine-specific histone demethylases that has been suggested as a lead compound for cancer therapy. The goal of this study was to explore the effects of PBIT within human prostate cancers. Micromolar concentrations of PBIT altered proliferation of castration-sensitive LNCaP and castration-resistant C4-2B, LNCaP-MDV3100 and PC-3 human prostate cancer cell lines. We then characterized the mechanism underlying the anti-proliferative effects of PBIT within the C4-2B and PC-3 cell lines. Data from Cell Death ELISAs suggest that PBIT does not induce apoptosis within C4-2B or PC-3 cells. However, PBIT did increase the amount of senescence associated beta-galactosidase. PBIT also altered cell cycle progression and increased protein levels of the cell cycle protein p21. PC-3 and C4-2B cells express varying amounts of KDM5A, KDM5B, and KDM5C, the therapeutic targets of PBIT. siRNA-mediated knockdown studies suggest that inhibition of multiple KDM5 isoforms contribute to the anti-proliferative effect of PBIT. Furthermore, combination treatments involving PBIT and the PPARγ agonist 15-deoxy-Δ-12, 14 -prostaglandin J2 (15d-PGJ2) also reduced PC-3 cell proliferation. Together, these data strongly suggest that PBIT significantly reduces the proliferation of prostate cancers via a mechanism that involves cell cycle arrest and senescence.
Assuntos
Neoplasias de Próstata Resistentes à Castração , Masculino , Humanos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/metabolismo , Proliferação de Células , Linhagem Celular Tumoral , Pontos de Checagem do Ciclo Celular , Apoptose , Ciclo Celular , Proteína 2 de Ligação ao Retinoblastoma/metabolismoRESUMO
To uncover the precise mechanisms coordinating proliferation and fate choice of stem cells, in this issue of Molecular Cell and in an accompanying paper in Cell Reports, Mazo and colleagues (Petruk et al. 2017a, 2017b) reveal that delayed accumulation of H3K27me3 on nascent DNA is essential to recruit pioneer transcription factors in stem cell differentiation.
Assuntos
Diferenciação Celular/genética , Fatores de Transcrição , HumanosRESUMO
Autophagy is a fundamental cellular process of protein degradation and recycling that regulates immune signaling pathways via multiple mechanisms. However, it remains unclear how autophagy epigenetically regulates the immune response. Here, we identified TRIM14 as an epigenetic regulator that reduces histone H3K9 trimethylation by inhibiting the autophagic degradation of the histone demethylase KDM4D. TRIM14 recruited the deubiquitinases USP14 and BRCC3 to cleave the K63-linked ubiquitin chains of KDM4D, which prevented KDM4D from undergoing optineurin (OPTN)-mediated selective autophagy. Tripartite motif-containing 14 (TRIM14) deficiency in dendritic cells significantly impaired the expression of the KDM4D-directed proinflammatory cytokines interleukin 12 (Il12) and Il23 and protected mice from autoimmune inflammation. Taken together, these findings highlight the cross-talk between epigenetic regulation and autophagy and suggest TRIM14 is a potential target of therapeutic intervention for inflammation-related diseases.