Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.656
Filtrar
1.
Gut ; 69(2): 365-379, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31076403

RESUMO

OBJECTIVE: Hepatocellular carcinoma (HCC), mostly developed in fibrotic/cirrhotic liver, exhibits relatively low responsiveness to immune checkpoint blockade (ICB) therapy. As myeloid-derived suppressor cell (MDSC) is pivotal for immunosuppression, we investigated its role and regulation in the fibrotic microenvironment with an aim of developing mechanism-based combination immunotherapy. DESIGN: Functional significance of MDSCs was evaluated by flow cytometry using two orthotopic HCC models in fibrotic liver setting via carbon tetrachloride or high-fat high-carbohydrate diet and verified by clinical specimens. Mechanistic studies were conducted in human hepatic stellate cell (HSC)-peripheral blood mononuclear cell culture systems and fibrotic-HCC patient-derived MDSCs. The efficacy of single or combined therapy with anti-programmed death-1-ligand-1 (anti-PD-L1) and a clinically trialled BET bromodomain inhibitor i-BET762 was determined. RESULTS: Accumulation of monocytic MDSCs (M-MDSCs), but not polymorphonuclear MDSCs, in fibrotic livers significantly correlated with reduced tumour-infiltrating lymphocytes (TILs) and increased tumorigenicity in both mouse models. In human HCCs, the tumour-surrounding fibrotic livers were markedly enriched with M-MDSC, with its surrogate marker CD33 significantly associated with aggressive tumour phenotypes and poor survival rates. Mechanistically, activated HSCs induced monocyte-intrinsic p38 MAPK signalling to trigger enhancer reprogramming for M-MDSC development and immunosuppression. Treatment with p38 MAPK inhibitor abrogated HSC-M-MDSC crosstalk to prevent HCC growth. Concomitant with patient-derived M-MDSC suppression by i-BET762, combined treatment with anti-PD-L1 synergistically enhanced TILs, resulting in tumour eradication and prolonged survival in the fibrotic-HCC mouse model. CONCLUSION: Our results signify how non-tumour-intrinsic properties in the desmoplastic microenvironment can be exploited to reinstate immunosurveillance, providing readily translatable combination strategies to empower HCC immunotherapy.


Assuntos
Carcinoma Hepatocelular/terapia , Imunoterapia/métodos , Neoplasias Hepáticas/terapia , Animais , Antígeno B7-H1/antagonistas & inibidores , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/imunologia , Reprogramação Celular/imunologia , Ciclopropanos/farmacologia , Ciclopropanos/uso terapêutico , Células Estreladas do Fígado/imunologia , Humanos , Tolerância Imunológica , Cirrose Hepática/complicações , Cirrose Hepática/patologia , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas Experimentais/etiologia , Neoplasias Hepáticas Experimentais/imunologia , Neoplasias Hepáticas Experimentais/patologia , Neoplasias Hepáticas Experimentais/terapia , Masculino , Camundongos Endogâmicos C57BL , Monócitos/imunologia , Células Supressoras Mieloides/imunologia , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Piridinas/farmacologia , Piridinas/uso terapêutico , Transdução de Sinais/fisiologia , Células Tumorais Cultivadas , Microambiente Tumoral , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologia
2.
Yi Chuan ; 41(12): 1099-1109, 2019 Dec 20.
Artigo em Chinês | MEDLINE | ID: mdl-31857281

RESUMO

Somatic cell nuclear transfer (SCNT) is the only reproductive engineering technique that can confer genomic totipotency on somatic cell. SCNT is of great significance for animal germplasm conservation, animal husbandry development, and biomedical research. Although many research advances have been made in this technology, the developmental rate of SCNT mammalian embryos is very low, which seriously limits the application of SCNT in animal husbandry and biomedicine. The primary reason for the low efficiency of cloned embryos is somatic cell reprogramming errors or incomplete reprogramming. These errors or incompleteness present as the abnormal expression of imprinted gene Xist, abnormal DNA methylation, and abnormal histone modification. In this review, we summarize the main factors that influence the low development efficiency of mammalian cloned embryos to provide theoretical reference for the research and practice of improving somatic cell cloning efficiency.


Assuntos
Reprogramação Celular , Epigênese Genética , Técnicas de Transferência Nuclear , Animais , Clonagem de Organismos , Metilação de DNA , Embrião de Mamíferos , Desenvolvimento Embrionário , Mamíferos
3.
Adv Exp Med Biol ; 1190: 281-297, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31760651

RESUMO

Gliomas are a heterogeneous group of tumors with evolving classification based on genotype. Isocitrate dehydrogenase (IDH) mutation is an early event in the formation of some diffuse gliomas, and is the best understood mechanism of their epigenetic dysregulation. Glioblastoma may evolve from lower-grade lesions with IDH mutations, or arise independently from copy number changes in platelet-derived growth factor receptor alpha (PDGFRA) and phosphatase and tensin homolog (PTEN). Several molecular subtypes of glioblastoma arise from a common proneural precursor with a tendency toward transition to a mesenchymal subtype. Following oncogenic transformation, gliomas escape growth arrest through a distinct step of aberrant telomere reverse transcriptase (TERT) expression, or mutations in either alpha thalassemia/mental retardation syndrome (ATRX) or death-domain associated protein (DAXX) genes. Metabolic reprogramming allows gliomas to thrive in harsh microenvironments such as hypoxia, acidity, and nutrient depletion, which contribute to tumor initiation, maintenance, and treatment resistance.


Assuntos
Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Glioma/patologia , Reprogramação Celular , Humanos , Isocitrato Desidrogenase/genética , Mutação , PTEN Fosfo-Hidrolase/genética , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Telomerase/genética , Microambiente Tumoral , Proteína Nuclear Ligada ao X/genética
4.
DNA Cell Biol ; 38(12): 1470-1479, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31633376

RESUMO

Vascular smooth muscle cells (VSMCs) of ascending aorta and TBX18+ sinus node both originated from the second heart field. The study explored whether ascending aortic smooth muscle cells in vitro could be reprogrammed into pacemaker-like cells with human TBX18. In the study, VSMCs were infected with TBX18, and then cocultured with neonatal rat ventricular cardiomyocytes (NRVMs) in vitro. By overexpressing TBX18, the transfected VSMCs expressed high levels of hyperpolarization-activated cyclic nucleotide-gated channel 4 (HCN4), insulin gene enhancer binding protein 1, and human dwarf homeobox gene SHOX2, cardiac troponin I, and low level of connexin 43. In addition, funny current (If) was recorded by patch clamp appeared the time and voltage dependence in TBX18 group, which the amplitude of If density was from -5.164 ± 0.662 pA/pF to -0.765 ± 0.358 pA/pF (n = 14). Furthermore, TBX18-transfected VSMCs coupled with NRVMs showed typical action potential of pacemaker-like cells and the beating rate was faster (178.00 ± 7.55 bpm, p < 0.05) compared with other groups. In conclusion, our study indicated that transcription factor TBX18 could reprogram VSMCs into pacemaker-like cells in vitro.


Assuntos
Aorta/citologia , Reprogramação Celular , Músculo Liso Vascular/citologia , Miócitos Cardíacos/citologia , Marca-Passo Artificial , Proteínas com Domínio T/metabolismo , Animais , Animais Recém-Nascidos , Aorta/metabolismo , Diferenciação Celular , Células Cultivadas , Masculino , Músculo Liso Vascular/metabolismo , Miócitos Cardíacos/metabolismo , Ratos , Ratos Sprague-Dawley
5.
Nature ; 574(7779): 553-558, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31645721

RESUMO

Age-associated chronic inflammation (inflammageing) is a central hallmark of ageing1, but its influence on specific cells remains largely unknown. Fibroblasts are present in most tissues and contribute to wound healing2,3. They are also the most widely used cell type for reprogramming to induced pluripotent stem (iPS) cells, a process that has implications for regenerative medicine and rejuvenation strategies4. Here we show that fibroblast cultures from old mice secrete inflammatory cytokines and exhibit increased variability in the efficiency of iPS cell reprogramming between mice. Variability between individuals is emerging as a feature of old age5-8, but the underlying mechanisms remain unknown. To identify drivers of this variability, we performed multi-omics profiling of fibroblast cultures from young and old mice that have different reprogramming efficiencies. This approach revealed that fibroblast cultures from old mice contain 'activated fibroblasts' that secrete inflammatory cytokines, and that the proportion of activated fibroblasts in a culture correlates with the reprogramming efficiency of that culture. Experiments in which conditioned medium was swapped between cultures showed that extrinsic factors secreted by activated fibroblasts underlie part of the variability between mice in reprogramming efficiency, and we have identified inflammatory cytokines, including TNF, as key contributors. Notably, old mice also exhibited variability in wound healing rate in vivo. Single-cell RNA-sequencing analysis identified distinct subpopulations of fibroblasts with different cytokine expression and signalling in the wounds of old mice with slow versus fast healing rates. Hence, a shift in fibroblast composition, and the ratio of inflammatory cytokines that they secrete, may drive the variability between mice in reprogramming in vitro and influence wound healing rate in vivo. This variability may reflect distinct stochastic ageing trajectories between individuals, and could help in developing personalized strategies to improve iPS cell generation and wound healing in elderly individuals.


Assuntos
Envelhecimento/metabolismo , Reprogramação Celular , Senescência Celular/fisiologia , Fibroblastos/metabolismo , Cicatrização , Animais , Linhagem Celular , Reprogramação Celular/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Citocinas/metabolismo , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/metabolismo , Mediadores da Inflamação/metabolismo , Judeus/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Análise de Sequência de RNA , Transdução de Sinais/efeitos dos fármacos , Análise de Célula Única , Processos Estocásticos , Fatores de Tempo , Cicatrização/efeitos dos fármacos
6.
EMBO J ; 38(22): e101681, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31583744

RESUMO

Epigenetic modifications operate in concert to maintain cell identity, yet how these interconnected networks suppress alternative cell fates remains unknown. Here, we uncover a link between the removal of repressive histone H3K9 methylation and DNA methylation during the reprogramming of somatic cells to pluripotency. The H3K9me2 demethylase, Kdm3b, transcriptionally controls DNA hydroxymethylase Tet1 expression. Unexpectedly, in the absence of Kdm3b, loci that must be DNA demethylated are trapped in an intermediate hydroxymethylated (5hmC) state and do not resolve to unmethylated cytosine. Ectopic 5hmC trapping precludes the chromatin association of master pluripotency factor, POU5F1, and pluripotent gene activation. Increased Tet1 expression is important for the later intermediates of the reprogramming process. Taken together, coordinated removal of distinct chromatin modifications appears to be an important mechanism for altering cell identity.


Assuntos
Linhagem da Célula/genética , Reprogramação Celular , Cromatina/genética , Metilação de DNA , Epigênese Genética , Histonas/genética , Células-Tronco Pluripotentes Induzidas/citologia , Animais , Células Cultivadas , Proteínas de Ligação a DNA/fisiologia , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Pluripotentes Induzidas/metabolismo , Histona Desmetilases com o Domínio Jumonji/fisiologia , Camundongos , Camundongos Knockout , Fator 3 de Transcrição de Octâmero/metabolismo , Proteínas Proto-Oncogênicas/fisiologia
7.
PLoS Genet ; 15(10): e1008410, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31584940

RESUMO

Mitochondria have been increasingly recognized as a central regulatory nexus for multiple metabolic pathways, in addition to ATP production via oxidative phosphorylation (OXPHOS). Here we show that inducing mitochondrial DNA (mtDNA) stress in Drosophila using a mitochondrially-targeted Type I restriction endonuclease (mtEcoBI) results in unexpected metabolic reprogramming in adult flies, distinct from effects on OXPHOS. Carbohydrate utilization was repressed, with catabolism shifted towards lipid oxidation, accompanied by elevated serine synthesis. Cleavage and translocation, the two modes of mtEcoBI action, repressed carbohydrate rmetabolism via two different mechanisms. DNA cleavage activity induced a type II diabetes-like phenotype involving deactivation of Akt kinase and inhibition of pyruvate dehydrogenase, whilst translocation decreased post-translational protein acetylation by cytonuclear depletion of acetyl-CoA (AcCoA). The associated decrease in the concentrations of ketogenic amino acids also produced downstream effects on physiology and behavior, attributable to decreased neurotransmitter levels. We thus provide evidence for novel signaling pathways connecting mtDNA to metabolism, distinct from its role in supporting OXPHOS.


Assuntos
Reprogramação Celular/genética , DNA Mitocondrial/genética , Diabetes Mellitus Tipo 2/genética , Mitocôndrias/genética , Trifosfato de Adenosina/genética , Animais , Metabolismo dos Carboidratos/genética , Carboidratos/genética , Enzimas de Restrição do DNA/genética , Diabetes Mellitus Tipo 2/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Humanos , Redes e Vias Metabólicas/genética , Mitocôndrias/metabolismo , Fosforilação Oxidativa , Estresse Oxidativo/genética
8.
Nat Commun ; 10(1): 4444, 2019 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-31570708

RESUMO

Ectopic transcription factor expression enables reprogramming of somatic cells to pluripotency, albeit with generally low efficiency. Despite steady progress in the field, the exact molecular mechanisms that coordinate this remarkable transition still remain largely elusive. To better characterize the final steps of pluripotency induction, we optimized an experimental system where pluripotent stem cells are differentiated for set intervals before being reintroduced to pluripotency-supporting conditions. Using this approach, we identify a transient period of high-efficiency reprogramming where ectopic transcription factors, but not serum/LIF alone, rapidly revert cells to pluripotency with near 100% efficiency. After this period, cells reprogram with somatic-like kinetics and efficiencies. We identify a set of OCT4 bound cis-regulatory elements that are dynamically regulated during this transient phase and appear central to facilitating reprogramming. Interestingly, these regions remain hypomethylated during in vitro and in vivo differentiation, which may allow them to act as primary targets of ectopically induced factors during somatic cell reprogramming.


Assuntos
Diferenciação Celular/fisiologia , Reprogramação Celular/fisiologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Fator 3 de Transcrição de Octâmero/metabolismo , Fatores de Transcrição/metabolismo , Animais , Linhagem Celular , Fibroblastos , Regulação da Expressão Gênica , Genômica , Cinética , Camundongos , Proteína Homeobox Nanog , Fator 3 de Transcrição de Octâmero/genética , Células-Tronco
9.
Nucleic Acids Res ; 47(19): 10115-10133, 2019 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-31555818

RESUMO

Pluripotency and cell fates can be modulated through the regulation of super-enhancers; however, the underlying mechanisms are unclear. Here, we showed a novel mechanism in which Ash2l directly binds to super-enhancers of several stemness genes to regulate pluripotency and self-renewal in pluripotent stem cells. Ash2l recruits Oct4/Sox2/Nanog (OSN) to form Ash2l/OSN complex at the super-enhancers of Jarid2, Nanog, Sox2 and Oct4, and further drives enhancer activation, upregulation of stemness genes, and maintains the pluripotent circuitry. Ash2l knockdown abrogates the OSN recruitment to all super-enhancers and further hinders the enhancer activation. In addition, CRISPRi/dCas9-mediated blocking of Ash2l-binding motifs at these super-enhancers also prevents OSN recruitment and enhancer activation, validating that Ash2l directly binds to super-enhancers and initiates the pluripotency network. Transfection of Ash2l with W118A mutation to disrupt Ash2l-Oct4 interaction fails to rescue Ash2l-driven enhancer activation and pluripotent gene upregulation in Ash2l-depleted pluripotent stem cells. Together, our data demonstrated Ash2l formed an enhancer-bound Ash2l/OSN complex that can drive enhancer activation, govern pluripotency network and stemness circuitry.


Assuntos
Proteínas de Ligação a DNA/genética , Elementos Facilitadores Genéticos , Células-Tronco Embrionárias Murinas/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Fatores de Transcrição/genética , Animais , Sistemas CRISPR-Cas/genética , Diferenciação Celular/genética , Linhagem da Célula/genética , Autorrenovação Celular/genética , Reprogramação Celular/genética , Elementos Facilitadores Genéticos/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Humanos , Camundongos , Mutação/genética , Proteína Homeobox Nanog/genética , Células-Tronco Pluripotentes/metabolismo , Fatores de Transcrição SOXB1/genética , Transfecção
10.
Nat Cell Biol ; 21(10): 1179-1190, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31548608

RESUMO

Cell fate transitions are accompanied by global transcriptional, epigenetic and topological changes driven by transcription factors, as is exemplified by reprogramming somatic cells to pluripotent stem cells through the expression of OCT4, KLF4, SOX2 and cMYC. How transcription factors orchestrate the complex molecular changes around their target gene loci remains incompletely understood. Here, using KLF4 as a paradigm, we provide a transcription-factor-centric view of chromatin reorganization and its association with three-dimensional enhancer rewiring and transcriptional changes during the reprogramming of mouse embryonic fibroblasts to pluripotent stem cells. Inducible depletion of KLF factors in PSCs caused a genome-wide decrease in enhancer connectivity, whereas disruption of individual KLF4 binding sites within pluripotent-stem-cell-specific enhancers was sufficient to impair enhancer-promoter contacts and reduce the expression of associated genes. Our study provides an integrative view of the complex activities of a lineage-specifying transcription factor and offers novel insights into the nature of the molecular events that follow transcription factor binding.


Assuntos
Reprogramação Celular/genética , Montagem e Desmontagem da Cromatina/genética , Elementos Facilitadores Genéticos , Fatores de Transcrição Kruppel-Like/metabolismo , Células-Tronco Embrionárias Murinas/metabolismo , Animais , Células Cultivadas , Feminino , Células HEK293 , Humanos , Masculino , Camundongos , Células-Tronco Pluripotentes/metabolismo
11.
F1000Res ; 82019.
Artigo em Inglês | MEDLINE | ID: mdl-31559012

RESUMO

Scientific and technological advances of the past decade have shed light on the mechanisms underlying cell fate acquisition, including its transcriptional and epigenetic regulation during embryonic development. This knowledge has enabled us to purposefully engineer cell fates in vitro by manipulating expression levels of lineage-instructing transcription factors. Here, we review the state of the art in the cell programming field with a focus on the derivation of neural cells. We reflect on what we know about the mechanisms underlying fate changes in general and on the degree of epigenetic remodeling conveyed by the distinct reprogramming and direct conversion strategies available. Moreover, we discuss the implications of residual epigenetic memory for biomedical applications such as disease modeling and neuroregeneration. Finally, we cover recent developments approaching cell fate conversion in the living brain and define questions which need to be addressed before cell programming can become an integral part of translational medicine.


Assuntos
Reprogramação Celular , Epigênese Genética , Diferenciação Celular , Desenvolvimento Embrionário , Fatores de Transcrição
12.
J Biosci ; 44(4)2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31502583

RESUMO

It has been proposed that age reprogramming enables old cells to be rejuvenated without passage through an embryonic stage (Singh and Zacouto in J. Biosci. 35 315-319, 2010). As such, age reprogramming stands apart from the induced pluripotent stem (iPS) and nuclear transfer-embryonic stem (NT-ES) cell therapies where histo-compatible cells are produced only after passage through an embryonic stage. It avoids many of the disadvantages associated with iPS and NT-ES cell therapies. Experimental evidence in support of age reprogramming is burgeoning. Here, we discuss possible new approaches to enhance age reprogramming, which will have considerable benefits for regenerative therapies.


Assuntos
Envelhecimento/genética , Reprogramação Celular/genética , Epigênese Genética/genética , Células-Tronco Embrionárias/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Medicina Regenerativa
13.
Nat Commun ; 10(1): 3974, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31481662

RESUMO

Tumor-associated macrophages (TAMs) usually express an M2 phenotype, which enables them to perform immunosuppressive and tumor-promoting functions. Reprogramming these TAMs toward an M1 phenotype could thwart their pro-cancer activities and unleash anti-tumor immunity, but efforts to accomplish this are nonspecific and elicit systemic inflammation. Here we describe a targeted nanocarrier that can deliver in vitro-transcribed mRNA encoding M1-polarizing transcription factors to reprogram TAMs without causing systemic toxicity. We demonstrate in models of ovarian cancer, melanoma, and glioblastoma that infusions of nanoparticles formulated with mRNAs encoding interferon regulatory factor 5 in combination with its activating kinase IKKß reverse the immunosuppressive, tumor-supporting state of TAMs and reprogram them to a phenotype that induces anti-tumor immunity and promotes tumor regression. We further establish that these nanoreagents are safe for repeated dosing. Implemented in the clinic, this immunotherapy could enable physicians to obviate suppressive tumors while avoiding systemic treatments that disrupt immune homeostasis.


Assuntos
Macrófagos/imunologia , Nanopartículas , Neoplasias/imunologia , RNA Mensageiro/administração & dosagem , Animais , Linhagem Celular Tumoral , Reprogramação Celular , Feminino , Glioblastoma/imunologia , Glioblastoma/patologia , Glioblastoma/terapia , Humanos , Quinase I-kappa B/genética , Quinase I-kappa B/metabolismo , Imunossupressão , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/metabolismo , Ativação de Macrófagos , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Melanoma Experimental/terapia , Camundongos , Metástase Neoplásica , Neoplasias/genética , Neoplasias/patologia , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/terapia , RNA Mensageiro/genética , Linfócitos T/imunologia , Fatores de Transcrição/genética , Transfecção
14.
Mol Carcinog ; 58(11): 2161-2174, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31486135

RESUMO

Metabolic reprogramming (including the Warburg effect) is a hallmark of cancer, yet the association between the altered metabolism and chemoresistance remains elusive. Hexokinase II (HKII) is a key metabolic enzyme and is upregulated in multiple cancers. In this study, we examined the impact of targeting metabolism via silencing of HKII on chemoresistance in ovarian cancer (OVCA). In addition, the regulatory molecular mechanism of tumor metabolism was examined using gain- and loss-of-function approaches in epithelial OVCA cell lines of various histological subtypes. We demonstrated that cisplatin (CDDP)-induced p53-mediated HKII downregulation is a determinant of chemosensitivity in OVCA. Silencing of HKII sensitized chemoresistant OVCA cells to apoptosis in a p53-dependent manner. As a negative regulator, p53 suppressed HKII transcription by promoter binding and decreased glycolysis. Pyruvate dehydrogenase kinase-1 (PDK1) is a key regulator of cell proliferation involved in Akt signaling axis. Our Gene Expression Profiling Interactive Analysis (GEPIA) and molecular studies also revealed that PDK1, an upstream activator strongly correlates with HKII expression and regulates its metabolic activity. Finally, we demonstrated that the clinically approved drug metformin sensitizes chemoresistant OVCA cells to CDDP via PDK1-HKII pathway. Collectively, our data implicate that p53--PDK1-HKII axis is a central regulatory component of metabolism conferring chemoresistance in OVCA.


Assuntos
Carcinoma Epitelial do Ovário/tratamento farmacológico , Hexoquinase/genética , Proteína Supressora de Tumor p53/genética , Apoptose/efeitos dos fármacos , Carcinoma Epitelial do Ovário/genética , Carcinoma Epitelial do Ovário/patologia , Proliferação de Células/efeitos dos fármacos , Reprogramação Celular/efeitos dos fármacos , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Hexoquinase/antagonistas & inibidores , Humanos , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais/efeitos dos fármacos
15.
Mol Cell ; 75(6): 1203-1217.e5, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31494035

RESUMO

In response to foreign and endogenous double-stranded RNA (dsRNA), protein kinase R (PKR) and ribonuclease L (RNase L) reprogram translation in mammalian cells. PKR inhibits translation initiation through eIF2α phosphorylation, which triggers stress granule (SG) formation and promotes translation of stress responsive mRNAs. The mechanisms of RNase L-driven translation repression, its contribution to SG assembly, and its regulation of dsRNA stress-induced mRNAs are unknown. We demonstrate that RNase L drives translational shut-off in response to dsRNA by promoting widespread turnover of mRNAs. This alters stress granule assembly and reprograms translation by allowing translation of mRNAs resistant to RNase L degradation, including numerous antiviral mRNAs such as interferon (IFN)-ß. Individual cells differentially activate dsRNA responses revealing variation that can affect cellular outcomes. This identifies bulk mRNA degradation and the resistance of antiviral mRNAs as the mechanism by which RNase L reprograms translation in response to dsRNA.


Assuntos
Reprogramação Celular , Endorribonucleases/metabolismo , Interferon beta/biossíntese , Biossíntese de Proteínas , RNA Mensageiro/metabolismo , eIF-2 Quinase/metabolismo , Células A549 , Endorribonucleases/genética , Células HEK293 , Humanos , Interferon beta/genética , Estabilidade de RNA , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , RNA Mensageiro/genética , eIF-2 Quinase/genética
16.
Nat Immunol ; 20(9): 1208-1219, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31384057

RESUMO

Regulatory T cells (Treg cells) deficient in the transcription factor Foxp3 lack suppressor function and manifest an effector T (Teff) cell-like phenotype. We demonstrate that Foxp3 deficiency dysregulates metabolic checkpoint kinase mammalian target of rapamycin (mTOR) complex 2 (mTORC2) signaling and gives rise to augmented aerobic glycolysis and oxidative phosphorylation. Specific deletion of the mTORC2 adaptor gene Rictor in Foxp3-deficient Treg cells ameliorated disease in a Foxo1 transcription factor-dependent manner. Rictor deficiency re-established a subset of Treg cell genetic circuits and suppressed the Teff cell-like glycolytic and respiratory programs, which contributed to immune dysregulation. Treatment of Treg cells from patients with FOXP3 deficiency with mTOR inhibitors similarly antagonized their Teff cell-like program and restored suppressive function. Thus, regulatory function can be re-established in Foxp3-deficient Treg cells by targeting their metabolic pathways, providing opportunities to restore tolerance in Treg cell disorders.


Assuntos
Reprogramação Celular/imunologia , Fatores de Transcrição Forkhead/genética , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Proteína Companheira de mTOR Insensível à Rapamicina/genética , Linfócitos T Reguladores/imunologia , Animais , Células Cultivadas , Feminino , Regulação da Expressão Gênica , Glicólise/fisiologia , Humanos , Masculino , Alvo Mecanístico do Complexo 2 de Rapamicina/antagonistas & inibidores , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação Oxidativa , Transdução de Sinais , Linfócitos T Reguladores/citologia
17.
Genes Cells ; 24(10): 667-673, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31386786

RESUMO

Analysis of gene expression in single cells is required to understand somatic cell reprogramming into human induced pluripotent stem cells (iPSCs). To facilitate this, we established intermediately reprogrammed stem cells (iRSCs), pre-iPSC lines. The iRSC-iPSC conversion system enables the reproducible monitoring of reprogramming events and the analysis of progressive gene expression profiles using single-cell microarray analysis and genome editing. Here, single-cell microarray analysis showed the stage-specific sequential gene activation during the conversion of iRSCs into iPSCs, using OCT4, TDGF1 and E-CADHERIN as marker genes. Out of 75 OCT4-related genes, which were significantly up-regulated after the activation of OCT4, and entry into the mesenchymal-to-epithelial transition (MET), LIN28 (LIN28A) and FOXO1 were selected for applying to gene expression visualization. Multicolored visualization was achieved by the genome editing of LIN28 or FOXO1 with mCherry into OCT4-GFP iRSCs. Fluorescent analysis of gene activity in individual cells showed that OCT4 was dispensable for maintenance, but required for activation, of the LIN28 and FOXO1 expression in reprogramming.


Assuntos
Técnicas de Reprogramação Celular/métodos , Reprogramação Celular/genética , Células-Tronco Pluripotentes Induzidas/citologia , Animais , Caderinas/metabolismo , Diferenciação Celular/genética , Células Cultivadas , Transição Epitelial-Mesenquimal , Proteínas Ligadas por GPI/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Camundongos , Proteínas de Neoplasias/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Fatores de Transcrição SOXB1/genética , Análise de Célula Única/métodos , Ativação Transcricional
18.
Mol Cell ; 75(3): 644-660.e5, 2019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-31398325

RESUMO

Cell-cell communication via ligand-receptor signaling is a fundamental feature of complex organs. Despite this, the global landscape of intercellular signaling in mammalian liver has not been elucidated. Here we perform single-cell RNA sequencing on non-parenchymal cells isolated from healthy and NASH mouse livers. Secretome gene analysis revealed a highly connected network of intrahepatic signaling and disruption of vascular signaling in NASH. We uncovered the emergence of NASH-associated macrophages (NAMs), which are marked by high expression of triggering receptors expressed on myeloid cells 2 (Trem2), as a feature of mouse and human NASH that is linked to disease severity and highly responsive to pharmacological and dietary interventions. Finally, hepatic stellate cells (HSCs) serve as a hub of intrahepatic signaling via HSC-derived stellakines and their responsiveness to vasoactive hormones. These results provide unprecedented insights into the landscape of intercellular crosstalk and reprogramming of liver cells in health and disease.


Assuntos
Comunicação Celular/genética , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/genética , Análise de Sequência de RNA , Animais , Reprogramação Celular/genética , Modelos Animais de Doenças , Células Estreladas do Fígado/metabolismo , Células Estreladas do Fígado/patologia , Humanos , Ligantes , Fígado/patologia , Macrófagos/metabolismo , Macrófagos/patologia , Camundongos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Transdução de Sinais/genética , Análise de Célula Única
19.
Immunity ; 51(2): 272-284.e7, 2019 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-31399282

RESUMO

Macrophage polarization is accompanied by drastic changes in L-arginine metabolism. Two L-arginine catalytic enzymes, iNOS and arginase 1, are well-characterized hallmark molecules of classically and alternatively activated macrophages, respectively. The third metabolic fate of L-arginine is the generation of creatine that acts as a key source of cellular energy reserve, yet little is known about the role of creatine in the immune system. Here, genetic, genomic, metabolic, and immunological analyses revealed that creatine reprogrammed macrophage polarization by suppressing M(interferon-γ [IFN-γ]) yet promoting M(interleukin-4 [IL-4]) effector functions. Mechanistically, creatine inhibited the induction of immune effector molecules, including iNOS, by suppressing IFN-γ-JAK-STAT1 transcription-factor signaling while supporting IL-4-STAT6-activated arginase 1 expression by promoting chromatin remodeling. Depletion of intracellular creatine by ablation of the creatine transporter Slc6a8 altered macrophage-mediated immune responses in vivo. These results uncover a previously uncharacterized role for creatine in macrophage polarization by modulating cellular responses to cytokines such as IFN-γ and IL-4.


Assuntos
Arginina/metabolismo , Creatina/metabolismo , Cirrose Hepática/metabolismo , Macrófagos/fisiologia , Proteínas de Membrana Transportadoras/metabolismo , Animais , Diferenciação Celular , Células Cultivadas , Reprogramação Celular , Humanos , Imunidade Celular , Interferon gama/metabolismo , Cirrose Hepática/induzido quimicamente , Proteínas de Membrana Transportadoras/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Transdução de Sinais , Tetracloroetileno
20.
Nat Genet ; 51(9): 1356-1368, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31406346

RESUMO

In mammalian cells, chromosomes are partitioned into megabase-sized topologically associating domains (TADs). TADs can be in either A (active) or B (inactive) subnuclear compartments, which exhibit early and late replication timing (RT), respectively. Here, we show that A/B compartments change coordinately with RT changes genome wide during mouse embryonic stem cell (mESC) differentiation. While A to B compartment changes and early to late RT changes were temporally inseparable, B to A changes clearly preceded late to early RT changes and transcriptional activation. Compartments changed primarily by boundary shifting, altering the compartmentalization of TADs facing the A/B compartment interface, which was conserved during reprogramming and confirmed in individual cells by single-cell Repli-seq. Differentiating mESCs altered single-cell Repli-seq profiles gradually but uniformly, transiently resembling RT profiles of epiblast-derived stem cells (EpiSCs), suggesting that A/B compartments might also change gradually but uniformly toward a primed pluripotent state. These results provide insights into how megabase-scale chromosome organization changes in individual cells during differentiation.


Assuntos
Núcleo Celular/metabolismo , Montagem e Desmontagem da Cromatina , Cromossomos/genética , Replicação do DNA , Células-Tronco Embrionárias Murinas/metabolismo , Análise de Célula Única/métodos , Análise Espaço-Temporal , Animais , Diferenciação Celular , Núcleo Celular/genética , Células Cultivadas , Reprogramação Celular , Feminino , Genoma , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células-Tronco Embrionárias Murinas/citologia , Neurônios/citologia , Neurônios/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA