RESUMEN
Remyelination failure in diseases like multiple sclerosis (MS) was thought to involve suppressed maturation of oligodendrocyte precursors; however, oligodendrocytes are present in MS lesions yet lack myelin production. We found that oligodendrocytes in the lesions are epigenetically silenced. Developing a transgenic reporter labeling differentiated oligodendrocytes for phenotypic screening, we identified a small-molecule epigenetic-silencing-inhibitor (ESI1) that enhances myelin production and ensheathment. ESI1 promotes remyelination in animal models of demyelination and enables de novo myelinogenesis on regenerated CNS axons. ESI1 treatment lengthened myelin sheaths in human iPSC-derived organoids and augmented (re)myelination in aged mice while reversing age-related cognitive decline. Multi-omics revealed that ESI1 induces an active chromatin landscape that activates myelinogenic pathways and reprograms metabolism. Notably, ESI1 triggered nuclear condensate formation of master lipid-metabolic regulators SREBP1/2, concentrating transcriptional co-activators to drive lipid/cholesterol biosynthesis. Our study highlights the potential of targeting epigenetic silencing to enable CNS myelin regeneration in demyelinating diseases and aging.
Asunto(s)
Epigénesis Genética , Vaina de Mielina , Oligodendroglía , Remielinización , Animales , Vaina de Mielina/metabolismo , Humanos , Ratones , Remielinización/efectos de los fármacos , Oligodendroglía/metabolismo , Sistema Nervioso Central/metabolismo , Ratones Endogámicos C57BL , Rejuvenecimiento , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/efectos de los fármacos , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Organoides/metabolismo , Organoides/efectos de los fármacos , Enfermedades Desmielinizantes/metabolismo , Enfermedades Desmielinizantes/genética , Diferenciación Celular/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/farmacología , Masculino , Regeneración/efectos de los fármacos , Esclerosis Múltiple/metabolismo , Esclerosis Múltiple/genética , Esclerosis Múltiple/tratamiento farmacológico , Esclerosis Múltiple/patologíaRESUMEN
Understanding transcription factor navigation through the nucleus remains critical for developing targeted therapeutics. The GLI1 transcription factor must maintain maximal Hedgehog pathway output in basal cell carcinomas (BCCs), and we have previously shown that resistant BCCs increase GLI1 deacetylation through atypical protein kinase Cι/λ (aPKC) and HDAC1. Here we identify a lamina-associated polypeptide 2 (LAP2) isoform-dependent nuclear chaperoning system that regulates GLI1 movement between the nuclear lamina and nucleoplasm to achieve maximal activation. LAP2ß forms a two-site interaction with the GLI1 zinc-finger domain and acetylation site, stabilizing an acetylation-dependent reserve on the inner nuclear membrane (INM). By contrast, the nucleoplasmic LAP2α competes with LAP2ß for GLI1 while scaffolding HDAC1 to deacetylate the secondary binding site. aPKC functions to promote GLI1 association with LAP2α, promoting egress off the INM. GLI1 intranuclear trafficking by LAP2 isoforms represents a powerful signal amplifier in BCCs with implications for zinc finger-based signal transduction and therapeutics.
Asunto(s)
Proteínas de Unión al ADN/metabolismo , Proteínas de la Membrana/metabolismo , Proteína con Dedos de Zinc GLI1/metabolismo , Células 3T3 , Animales , Carcinoma Basocelular/metabolismo , Línea Celular , Cromatina , Proteínas de Unión al ADN/fisiología , Células HEK293 , Proteínas Hedgehog/metabolismo , Proteínas Hedgehog/fisiología , Histona Desacetilasa 1/metabolismo , Humanos , Proteínas de la Membrana/fisiología , Ratones , Chaperonas Moleculares/metabolismo , Lámina Nuclear/metabolismo , Proteínas Nucleares/metabolismo , Isoformas de Proteínas/metabolismo , Transducción de Señal , Transactivadores/metabolismo , Factores de Transcripción/metabolismo , Proteína con Dedos de Zinc GLI1/fisiología , Dedos de ZincRESUMEN
Little is known about how metabolites couple tissue-specific stem cell function with physiology. Here we show that, in the mammalian small intestine, the expression of Hmgcs2 (3-hydroxy-3-methylglutaryl-CoA synthetase 2), the gene encoding the rate-limiting enzyme in the production of ketone bodies, including beta-hydroxybutyrate (ßOHB), distinguishes self-renewing Lgr5+ stem cells (ISCs) from differentiated cell types. Hmgcs2 loss depletes ßOHB levels in Lgr5+ ISCs and skews their differentiation toward secretory cell fates, which can be rescued by exogenous ßOHB and class I histone deacetylase (HDAC) inhibitor treatment. Mechanistically, ßOHB acts by inhibiting HDACs to reinforce Notch signaling, instructing ISC self-renewal and lineage decisions. Notably, although a high-fat ketogenic diet elevates ISC function and post-injury regeneration through ßOHB-mediated Notch signaling, a glucose-supplemented diet has the opposite effects. These findings reveal how control of ßOHB-activated signaling in ISCs by diet helps to fine-tune stem cell adaptation in homeostasis and injury.
Asunto(s)
Dieta Alta en Grasa , Cuerpos Cetónicos/metabolismo , Células Madre/metabolismo , Ácido 3-Hidroxibutírico/sangre , Ácido 3-Hidroxibutírico/farmacología , Anciano de 80 o más Años , Animales , Diferenciación Celular/efectos de los fármacos , Autorrenovación de las Células , Femenino , Inhibidores de Histona Desacetilasas/farmacología , Humanos , Hidroximetilglutaril-CoA Sintasa/deficiencia , Hidroximetilglutaril-CoA Sintasa/genética , Hidroximetilglutaril-CoA Sintasa/metabolismo , Intestinos/citología , Intestinos/patología , Masculino , Ratones , Ratones Noqueados , Receptores Acoplados a Proteínas G/metabolismo , Receptores Notch/metabolismo , Transducción de Señal/efectos de los fármacos , Células Madre/citología , Adulto JovenRESUMEN
Tuft cells in mucosal tissues are key regulators of type 2 immunity. Here, we examined the impact of the microbiota on tuft cell biology in the intestine. Succinate induction of tuft cells and type 2 innate lymphoid cells was elevated with loss of gut microbiota. Colonization with butyrate-producing bacteria or treatment with butyrate suppressed this effect and reduced intestinal histone deacetylase activity. Epithelial-intrinsic deletion of the epigenetic-modifying enzyme histone deacetylase 3 (HDAC3) inhibited tuft cell expansion in vivo and impaired type 2 immune responses during helminth infection. Butyrate restricted stem cell differentiation into tuft cells, and inhibition of HDAC3 in adult mice and human intestinal organoids blocked tuft cell expansion. Collectively, these data define a HDAC3 mechanism in stem cells for tuft cell differentiation that is dampened by a commensal metabolite, revealing a pathway whereby the microbiota calibrate intestinal type 2 immunity.
Asunto(s)
Mucosa Intestinal , Microbiota , Adulto , Ratones , Humanos , Animales , Células en Penacho , Butiratos/farmacología , Butiratos/metabolismo , Inmunidad Innata , Linfocitos/metabolismo , Intestinos , Histona Desacetilasas/metabolismo , Diferenciación CelularRESUMEN
BRAF(V600E) mutant melanomas treated with inhibitors of the BRAF and MEK kinases almost invariably develop resistance that is frequently caused by reactivation of the mitogen activated protein kinase (MAPK) pathway. To identify novel treatment options for such patients, we searched for acquired vulnerabilities of MAPK inhibitor-resistant melanomas. We find that resistance to BRAF+MEK inhibitors is associated with increased levels of reactive oxygen species (ROS). Subsequent treatment with the histone deacetylase inhibitor vorinostat suppresses SLC7A11, leading to a lethal increase in the already-elevated levels of ROS in drug-resistant cells. This causes selective apoptotic death of only the drug-resistant tumor cells. Consistently, treatment of BRAF inhibitor-resistant melanoma with vorinostat in mice results in dramatic tumor regression. In a study in patients with advanced BRAF+MEK inhibitor-resistant melanoma, we find that vorinostat can selectively ablate drug-resistant tumor cells, providing clinical proof of concept for the novel therapy identified here.
Asunto(s)
Resistencia a Antineoplásicos , Melanoma/tratamiento farmacológico , Neoplasias Cutáneas/tratamiento farmacológico , Sistema de Transporte de Aminoácidos y+/metabolismo , Animales , Apoptosis , Línea Celular Tumoral , Proliferación Celular , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Inhibidores de Histona Desacetilasas/farmacología , Humanos , MAP Quinasa Quinasa 1/metabolismo , Sistema de Señalización de MAP Quinasas , Melanoma/genética , Ratones , Mutación , Trasplante de Neoplasias , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas B-raf/genética , Especies Reactivas de Oxígeno/metabolismo , Neoplasias Cutáneas/genética , Resultado del Tratamiento , Vorinostat/farmacologíaRESUMEN
Combining DNA-demethylating agents (DNA methyltransferase inhibitors [DNMTis]) with histone deacetylase inhibitors (HDACis) holds promise for enhancing cancer immune therapy. Herein, pharmacologic and isoform specificity of HDACis are investigated to guide their addition to a DNMTi, thus devising a new, low-dose, sequential regimen that imparts a robust anti-tumor effect for non-small-cell lung cancer (NSCLC). Using in-vitro-treated NSCLC cell lines, we elucidate an interferon α/ß-based transcriptional program with accompanying upregulation of antigen presentation machinery, mediated in part through double-stranded RNA (dsRNA) induction. This is accompanied by suppression of MYC signaling and an increase in the T cell chemoattractant CCL5. Use of this combination treatment schema in mouse models of NSCLC reverses tumor immune evasion and modulates T cell exhaustion state towards memory and effector T cell phenotypes. Key correlative science metrics emerge for an upcoming clinical trial, testing enhancement of immune checkpoint therapy for NSCLC.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/terapia , Quimioterapia Combinada , Neoplasias Pulmonares/terapia , Escape del Tumor/efectos de los fármacos , Animales , Presentación de Antígeno/efectos de los fármacos , Antineoplásicos/uso terapéutico , Azacitidina/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Línea Celular Tumoral , Inhibidores de Histona Desacetilasas/uso terapéutico , Ácidos Hidroxámicos/uso terapéutico , Inmunoterapia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/inmunología , Ratones , Linfocitos T/inmunología , Transcriptoma , Microambiente TumoralRESUMEN
The anti-cancer target hRpn13 is a proteasome substrate receptor. However, hRpn13-targeting molecules do not impair its interaction with proteasomes or ubiquitin, suggesting other critical cellular activities. We find that hRpn13 depletion causes correlated proteomic and transcriptomic changes, with pronounced effects in myeloma cells for cytoskeletal and immune response proteins and bone-marrow-specific arginine deiminase PADI4. Moreover, a PROTAC against hRpn13 co-depletes PADI4, histone deacetylase HDAC8, and DNA methyltransferase MGMT. PADI4 binds and citrullinates hRpn13 and proteasomes, and proteasomes from PADI4-inhibited myeloma cells exhibit reduced peptidase activity. When off proteasomes, hRpn13 can bind HDAC8, and this interaction inhibits HDAC8 activity. Further linking hRpn13 to transcription, its loss reduces nuclear factor κB (NF-κB) transcription factor p50, which proteasomes generate by cleaving its precursor protein. NF-κB inhibition depletes hRpn13 interactors PADI4 and HDAC8. Altogether, we find that hRpn13 acts dually in protein degradation and expression and that proteasome constituency and, in turn, regulation varies by cell type.
Asunto(s)
Histona Desacetilasas , Péptidos y Proteínas de Señalización Intracelular , FN-kappa B , Arginina Deiminasa Proteína-Tipo 4 , Factores de Transcripción , Humanos , Epigénesis Genética , Histona Desacetilasas/genética , Histona Desacetilasas/metabolismo , FN-kappa B/genética , FN-kappa B/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteoma/metabolismo , Proteómica , Proteínas Represoras/metabolismo , Factores de Transcripción/metabolismo , Transcriptoma , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Arginina Deiminasa Proteína-Tipo 4/metabolismo , Línea Celular TumoralRESUMEN
Transcription and splicing of pre-messenger RNA are closely coordinated, but how this functional coupling is disrupted in human diseases remains unexplored. Using isogenic cell lines, patient samples, and a mutant mouse model, we investigated how cancer-associated mutations in SF3B1 alter transcription. We found that these mutations reduce the elongation rate of RNA polymerase II (RNAPII) along gene bodies and its density at promoters. The elongation defect results from disrupted pre-spliceosome assembly due to impaired protein-protein interactions of mutant SF3B1. The decreased promoter-proximal RNAPII density reduces both chromatin accessibility and H3K4me3 marks at promoters. Through an unbiased screen, we identified epigenetic factors in the Sin3/HDAC/H3K4me pathway, which, when modulated, reverse both transcription and chromatin changes. Our findings reveal how splicing factor mutant states behave functionally as epigenetic disorders through impaired transcription-related changes to the chromatin landscape. We also present a rationale for targeting the Sin3/HDAC complex as a therapeutic strategy.
Asunto(s)
Cromatina , Neoplasias , Animales , Humanos , Ratones , Cromatina/genética , Mutación , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , ARN Polimerasa II/genética , ARN Polimerasa II/metabolismo , Empalme del ARN/genética , Factores de Empalme de ARN/genética , Factores de Empalme de ARN/metabolismoRESUMEN
The nuclear receptor co-repressor (NCoR) complex mediates transcriptional repression dependent on histone deacetylation by histone deacetylase 3 (HDAC3) as a component of the complex. Unexpectedly, we found that signaling by the receptor activator of nuclear factor κB (RANK) converts the NCoR/HDAC3 co-repressor complex to a co-activator of AP-1 and NF-κB target genes that are required for mouse osteoclast differentiation. Accordingly, the dominant function of NCoR/HDAC3 complexes in response to RANK signaling is to activate, rather than repress, gene expression. Mechanistically, RANK signaling promotes RNA-dependent interaction of the transcriptional co-activator PGC1ß with the NCoR/HDAC3 complex, resulting in the activation of PGC1ß and inhibition of HDAC3 activity for acetylated histone H3. Non-coding RNAs Dancr and Rnu12, which are associated with altered human bone homeostasis, promote NCoR/HDAC3 complex assembly and are necessary for RANKL-induced osteoclast differentiation in vitro. These findings may be prototypic for signal-dependent functions of NCoR in other biological contexts.
Asunto(s)
Osteoclastos , ARN , Humanos , Ratones , Animales , Proteínas Co-Represoras/genética , Osteoclastos/metabolismo , Ligando RANK/genética , Co-Represor 1 de Receptor Nuclear/genética , Co-Represor 1 de Receptor Nuclear/metabolismo , Expresión GénicaRESUMEN
Promoting axon regeneration in the central and peripheral nervous system is of clinical importance in neural injury and neurodegenerative diseases. Both pro- and antiregeneration factors are being identified. We previously reported that the Rtca mediated RNA repair/splicing pathway restricts axon regeneration by inhibiting the nonconventional splicing of Xbp1 mRNA under cellular stress. However, the downstream effectors remain unknown. Here, through transcriptome profiling, we show that the tubulin polymerization-promoting protein (TPPP) ringmaker/ringer is dramatically increased in Rtca-deficient Drosophila sensory neurons, which is dependent on Xbp1. Ringer is expressed in sensory neurons before and after injury, and is cell-autonomously required for axon regeneration. While loss of ringer abolishes the regeneration enhancement in Rtca mutants, its overexpression is sufficient to promote regeneration both in the peripheral and central nervous system. Ringer maintains microtubule stability/dynamics with the microtubule-associated protein futsch/MAP1B, which is also required for axon regeneration. Furthermore, ringer lies downstream from and is negatively regulated by the microtubule-associated deacetylase HDAC6, which functions as a regeneration inhibitor. Taken together, our findings suggest that ringer acts as a hub for microtubule regulators that relays cellular status information, such as cellular stress, to the integrity of microtubules in order to instruct neuroregeneration.
Asunto(s)
Anilidas/metabolismo , Axones/fisiología , Proteínas de Drosophila/metabolismo , Drosophila/fisiología , Ácidos Hidroxámicos/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Regeneración/genética , Animales , Proteínas de Drosophila/genética , Regulación del Desarrollo de la Expresión Génica/genética , Proteínas Asociadas a Microtúbulos/metabolismo , Microtúbulos/genética , Unión Proteica , Empalme del ARN/genética , Células Receptoras Sensoriales/fisiologíaRESUMEN
Chromatin modifiers play critical roles in epidermal development, but the functions of histone deacetylases in this context are poorly understood. The class I HDAC, HDAC3, is of particular interest because it plays divergent roles in different tissues by partnering with tissue-specific transcription factors. We found that HDAC3 is expressed broadly in embryonic epidermis and is required for its orderly stepwise stratification. HDAC3 protein stability in vivo relies on NCoR and SMRT, which function redundantly in epidermal development. However, point mutations in the NCoR and SMRT deacetylase-activating domains, which are required for HDAC3's enzymatic function, permit normal stratification, indicating that HDAC3's roles in this context are largely independent of its histone deacetylase activity. HDAC3-bound sites are significantly enriched for predicted binding motifs for critical epidermal transcription factors including AP1, GRHL, and KLF family members. Our results suggest that among these, HDAC3 operates in conjunction with KLF4 to repress inappropriate expression of Tgm1, Krt16, and Aqp3 In parallel, HDAC3 suppresses expression of inflammatory cytokines through a Rela-dependent mechanism. These data identify HDAC3 as a hub coordinating multiple aspects of epidermal barrier acquisition.
Asunto(s)
Diferenciación Celular/genética , Células Epidérmicas/citología , Epidermis/embriología , Histona Desacetilasas/genética , Histona Desacetilasas/metabolismo , Animales , Embrión de Mamíferos , Eliminación de Gen , Regulación del Desarrollo de la Expresión Génica , Genes Letales/genética , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel/genética , Ratones , Ratones Endogámicos C57BL , Mutación , Co-Represor 1 de Receptor Nuclear/genética , Co-Represor 1 de Receptor Nuclear/metabolismo , Co-Represor 2 de Receptor Nuclear/genética , Co-Represor 2 de Receptor Nuclear/metabolismo , Dominios y Motivos de Interacción de Proteínas/genética , Factor de Transcripción ReIA/genética , Factor de Transcripción ReIA/metabolismoRESUMEN
The X inactive-specific transcript (Xist) gene is the master regulator of X chromosome inactivation in mammals. Xist produces a long noncoding (lnc)RNA that accumulates over the entire length of the chromosome from which it is transcribed, recruiting factors to modify underlying chromatin and silence X-linked genes in cis Recent years have seen significant progress in identifying important functional elements in Xist RNA, their associated RNA-binding proteins (RBPs), and the downstream pathways for chromatin modification and gene silencing. In this review, we summarize progress in understanding both how these pathways function in Xist-mediated silencing and the complex interplay between them.
Asunto(s)
Proteínas/metabolismo , ARN Largo no Codificante/metabolismo , Inactivación del Cromosoma X/genética , Proteínas de Unión al ADN/metabolismo , Silenciador del Gen/fisiología , Metiltransferasas/metabolismo , ARN Largo no Codificante/genética , Proteínas de Unión al ARN/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Receptor de Lamina BRESUMEN
The cellular activation of the NLRP3 inflammasome is spatiotemporally orchestrated by various organelles, but whether lysosomes contribute to this process remains unclear. Here, we show the vital role of the lysosomal membrane-tethered Ragulator complex in NLRP3 inflammasome activation. Deficiency of Lamtor1, an essential component of the Ragulator complex, abrogated NLRP3 inflammasome activation in murine macrophages and human monocytic cells. Myeloid-specific Lamtor1-deficient mice showed marked attenuation of NLRP3-associated inflammatory disease severity, including LPS-induced sepsis, alum-induced peritonitis, and monosodium urate (MSU)-induced arthritis. Mechanistically, Lamtor1 interacted with both NLRP3 and histone deacetylase 6 (HDAC6). HDAC6 enhances the interaction between Lamtor1 and NLRP3, resulting in NLRP3 inflammasome activation. DL-all-rac-α-tocopherol, a synthetic form of vitamin E, inhibited the Lamtor1-HDAC6 interaction, resulting in diminished NLRP3 inflammasome activation. Further, DL-all-rac-α-tocopherol alleviated acute gouty arthritis and MSU-induced peritonitis. These results provide novel insights into the role of lysosomes in the activation of NLRP3 inflammasomes by the Ragulator complex.
Asunto(s)
Inflamasomas , Peritonitis , Ratones , Humanos , Animales , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Inflamación , Histona Desacetilasa 6/genética , alfa-Tocoferol , Ácido Úrico , Peritonitis/inducido químicamente , Lisosomas , Ratones Endogámicos C57BLRESUMEN
Histone deacetylase 3 (HDAC3) is a crucial epigenetic modulator essential for various developmental and physiological functions. Although its dysfunction is increasingly recognized in abnormal phenotypes, to our knowledge, there have been no established reports of human diseases directly linked to HDAC3 dysfunction. Using trio exome sequencing and extensive phenotypic analysis, we correlated heterozygous de novo variants in HDAC3 with a neurodevelopmental disorder having variable clinical presentations, frequently associated with intellectual disability, developmental delay, epilepsy, and musculoskeletal abnormalities. In a cohort of six individuals, we identified missense variants in HDAC3 (c.277G>A [p.Asp93Asn], c.328G>A [p.Ala110Thr], c.601C>T [p.Pro201Ser], c. 797T>C [p.Leu266Ser], c.799G>A [p.Gly267Ser], and c.1075C>T [p.Arg359Cys]), all located in evolutionarily conserved sites and confirmed as de novo. Experimental studies identified defective deacetylation activity in the p.Asp93Asn, p.Pro201Ser, p.Leu266Ser, and p.Gly267Ser variants, positioned near the enzymatic pocket. In addition, proteomic analysis employing co-immunoprecipitation revealed that the disrupted interactions with molecules involved in the CoREST and NCoR complexes, particularly in the p.Ala110Thr variant, consist of a central pathogenic mechanism. Moreover, immunofluorescence analysis showed diminished nuclear to cytoplasmic fluorescence ratio in the p.Ala110Thr, p.Gly267Ser, and p.Arg359Cys variants, indicating impaired nuclear localization. Taken together, our study highlights that de novo missense variants in HDAC3 are associated with a broad spectrum of neurodevelopmental disorders, which emphasizes the complex role of HDAC3 in histone deacetylase activity, multi-protein complex interactions, and nuclear localization for proper physiological functions. These insights open new avenues for understanding the molecular mechanisms of HDAC3-related disorders and may inform future therapeutic strategies.
Asunto(s)
Epigénesis Genética , Histona Desacetilasas , Mutación Missense , Trastornos del Neurodesarrollo , Humanos , Histona Desacetilasas/genética , Histona Desacetilasas/metabolismo , Mutación Missense/genética , Trastornos del Neurodesarrollo/genética , Masculino , Femenino , Preescolar , Niño , Discapacidad Intelectual/genética , Secuenciación del Exoma , Adolescente , Discapacidades del Desarrollo/genética , Fenotipo , Lactante , Co-Represor 1 de Receptor Nuclear/genética , Co-Represor 1 de Receptor Nuclear/metabolismoRESUMEN
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.
Asunto(s)
Empalme Alternativo , Carcinogénesis/genética , Neoplasias Colorrectales/genética , Regulación Neoplásica de la Expresión Génica , Histona Demetilasas con Dominio de Jumonji/genética , Proteínas de Unión al ARN/genética , Transactivadores/genética , Acetilcoenzima A/deficiencia , Acetilación , Animales , Carcinogénesis/metabolismo , Carcinogénesis/patología , Movimiento Celular , Proliferación Celular , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Células HCT116 , Humanos , Histona Demetilasas con Dominio de Jumonji/antagonistas & inhibidores , Histona Demetilasas con Dominio de Jumonji/metabolismo , Células MCF-7 , Masculino , Ratones , Ratones Desnudos , Pronóstico , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Proteínas de Unión al ARN/antagonistas & inhibidores , Proteínas de Unión al ARN/metabolismo , Ribonucleoproteína Nuclear Pequeña U2/genética , Ribonucleoproteína Nuclear Pequeña U2/metabolismo , Transducción de Señal , Análisis de Supervivencia , Transactivadores/antagonistas & inhibidores , Transactivadores/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto , Factores de Transcripción p300-CBP/genética , Factores de Transcripción p300-CBP/metabolismoRESUMEN
Class II histone deacetylases (HDACs) are important in regulation of gene transcription during T cell development. However, our understanding of their cell-specific functions is limited. In this study, we reveal that class IIa Hdac4 and Hdac7 (Hdac4/7) are selectively induced in transcription, guiding the lineage-specific differentiation of mouse T-helper 17 (Th17) cells from naive CD4+ T cells. Importantly, Hdac4/7 are functionally dispensable in other Th subtypes. Mechanistically, Hdac4 interacts with the transcription factor (TF) JunB, facilitating the transcriptional activation of Th17 signature genes such as Il17a/f. Conversely, Hdac7 collaborates with the TF Aiolos and Smrt/Ncor1-Hdac3 corepressors to repress transcription of Th17 negative regulators, including Il2, in Th17 cell differentiation. Inhibiting Hdac4/7 through pharmacological or genetic methods effectively mitigates Th17 cell-mediated intestinal inflammation in a colitis mouse model. Our study uncovers molecular mechanisms where HDAC4 and HDAC7 function distinctively yet cooperatively in regulating ordered gene transcription during Th17 cell differentiation. These findings suggest a potential therapeutic strategy of targeting HDAC4/7 for treating Th17-related inflammatory diseases, such as ulcerative colitis.
Asunto(s)
Diferenciación Celular , Colitis , Histona Desacetilasas , Co-Represor 1 de Receptor Nuclear , Células Th17 , Animales , Células Th17/citología , Células Th17/metabolismo , Células Th17/inmunología , Histona Desacetilasas/metabolismo , Histona Desacetilasas/genética , Ratones , Colitis/genética , Colitis/metabolismo , Colitis/inmunología , Transcripción Genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Co-Represor 2 de Receptor Nuclear/metabolismo , Co-Represor 2 de Receptor Nuclear/genética , Interleucina-17/metabolismo , Regulación de la Expresión Génica , Ratones Endogámicos C57BL , Humanos , Proteínas Represoras/metabolismo , Proteínas Represoras/genética , Interleucina-2/metabolismoRESUMEN
Proteostasis and genomic integrity are respectively regulated by the endoplasmic reticulum-associated protein degradation (ERAD) and DNA damage repair signaling pathways, with both pathways essential for carcinogenesis and drug resistance. How these signaling pathways coordinate with each other remains unexplored. We found that ER stress specifically induces the DNA-PKcs-regulated nonhomologous end joining (NHEJ) pathway to amend DNA damage and impede cell death. Intriguingly, sustained ER stress rapidly decreased the activity of DNA-PKcs and DNA damage accumulated, facilitating a switch from adaptation to cell death. This DNA-PKcs inactivation was caused by increased KU70/KU80 protein degradation. Unexpectedly, the ERAD ligase HRD1 was found to efficiently destabilize the classic nuclear protein HDAC1 in the cytoplasm, by catalyzing HDAC1's polyubiquitination at lysine 74, at a late stage of ER stress. By abolishing HDAC1-mediated KU70/KU80 deacetylation, HRD1 transmits ER signals to the nucleus. The resulting enhanced KU70/KU80 acetylation provides binding sites for the nuclear E3 ligase TRIM25, resulting in the promotion of polyubiquitination and the degradation of KU70/KU80 proteins. Both in vitro and in vivo cancer models showed that genetic or pharmacological inhibition of HADC1 or DNA-PKcs sensitizes colon cancer cells to ER stress inducers, including the Food and Drug Administration-approved drug celecoxib. The antitumor effects of the combined approach were also observed in patient-derived xenograft models. These findings identify a mechanistic link between ER stress (ERAD) in the cytoplasm and DNA damage (NHEJ) pathways in the nucleus, indicating that combined anticancer strategies may be developed that induce severe ER stress while simultaneously inhibiting KU70/KU80/DNA-PKcs-mediated NHEJ signaling.
Asunto(s)
Daño del ADN , Estrés del Retículo Endoplásmico , Autoantígeno Ku , Ubiquitina-Proteína Ligasas , Humanos , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Autoantígeno Ku/metabolismo , Autoantígeno Ku/genética , Animales , Proteína Quinasa Activada por ADN/metabolismo , Proteína Quinasa Activada por ADN/genética , Ratones , Reparación del ADN por Unión de Extremidades , Histona Desacetilasa 1/metabolismo , Histona Desacetilasa 1/genética , Ubiquitinación , Reparación del ADN , Transducción de Señal , Línea Celular Tumoral , Retículo Endoplásmico/metabolismo , ProteolisisRESUMEN
The transcriptional co-regulator SIN3 influences gene expression through multiple interactions that include histone deacetylases. Haploinsufficiency and mutations in SIN3 are the underlying cause of Witteveen-Kolk syndrome and related intellectual disability and autism syndromes, emphasizing its key role in development. However, little is known about the diversity of its interactions and functions in developmental processes. Here, we show that loss of SIN-3, the single SIN3 homolog in Caenorhabditis elegans, results in maternal-effect sterility associated with de-regulation of the germline transcriptome, including de-silencing of X-linked genes. We identify at least two distinct SIN3 complexes containing specific histone deacetylases and show that they differentially contribute to fertility. Single-cell, single-molecule fluorescence in situ hybridization reveals that in sin-3 mutants the X chromosome becomes re-expressed prematurely and in a stochastic manner in individual germ cells, suggesting a role for SIN-3 in its silencing. Furthermore, we identify histone residues whose acetylation increases in the absence of SIN-3. Together, this work provides a powerful framework for the in vivo study of SIN3 and associated proteins.
Asunto(s)
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Histona Desacetilasas , Complejo Correpresor Histona Desacetilasa y Sin3 , Animales , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Células Germinativas/metabolismo , Histona Desacetilasas/genética , Histona Desacetilasas/metabolismo , Histonas/metabolismo , Hibridación Fluorescente in Situ , Cromosoma X/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Complejo Correpresor Histona Desacetilasa y Sin3/genética , Complejo Correpresor Histona Desacetilasa y Sin3/metabolismoRESUMEN
The histone deacetylase HDAC3 is associated with the NCoR/SMRT co-repressor complex, and its canonical function is in transcriptional repression, but it can also activate transcription. Here, we show that the repressor and activator functions of HDAC3 can be genetically separated in Drosophila. A lysine substitution in the N terminus (K26A) disrupts its catalytic activity and activator function, whereas a combination of substitutions (HEBI) abrogating the interaction with SMRTER enhances repressor activity beyond wild type in the early embryo. We conclude that the crucial functions of HDAC3 in embryo development involve catalytic-dependent gene activation and non-enzymatic repression by several mechanisms, including tethering of loci to the nuclear periphery.
Asunto(s)
Proteínas de Drosophila , Drosophila , Histona Desacetilasas , Proteínas Represoras , Animales , Drosophila/metabolismo , Regulación de la Expresión Génica , Proteínas Represoras/metabolismo , Proteínas de Drosophila/metabolismo , Histona Desacetilasas/metabolismoRESUMEN
HDAC8, a member of class I HDACs, plays a pivotal role in cell cycle regulation by deacetylating the cohesin subunit SMC3. While cyclins and CDKs are well-established cell cycle regulators, our knowledge of other regulators remains limited. Here we reveal the acetylation of K202 in HDAC8 as a key cell cycle regulator responsive to stress. K202 acetylation in HDAC8, primarily catalyzed by Tip60, restricts HDAC8 activity, leading to increased SMC3 acetylation and cell cycle arrest. Furthermore, cells expressing the mutant form of HDAC8 mimicking K202 acetylation display significant alterations in gene expression, potentially linked to changes in 3D genome structure, including enhanced chromatid loop interactions. K202 acetylation impairs cell cycle progression by disrupting the expression of cell cycle-related genes and sister chromatid cohesion, resulting in G2/M phase arrest. These findings indicate the reversible acetylation of HDAC8 as a cell cycle regulator, expanding our understanding of stress-responsive cell cycle dynamics.