RESUMO
MLL/SET methyltransferases catalyze methylation of histone 3 lysine 4 and play critical roles in development and cancer. We assessed MLL/SET proteins and found that SETD1A is required for survival of acute myeloid leukemia (AML) cells. Mutagenesis studies and CRISPR-Cas9 domain screening show the enzymatic SET domain is not necessary for AML cell survival but that a newly identified region termed the "FLOS" (functional location on SETD1A) domain is indispensable. FLOS disruption suppresses DNA damage response genes and induces p53-dependent apoptosis. The FLOS domain acts as a cyclin-K-binding site that is required for chromosomal recruitment of cyclin K and for DNA-repair-associated gene expression in S phase. These data identify a connection between the chromatin regulator SETD1A and the DNA damage response that is independent of histone methylation and suggests that targeting SETD1A and cyclin K complexes may represent a therapeutic opportunity for AML and, potentially, for other cancers.
Assuntos
Ciclinas/metabolismo , Dano ao DNA , Histona-Lisina N-Metiltransferase/metabolismo , Animais , Biocatálise , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Ciclinas/genética , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/genética , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/metabolismo , Regulação Leucêmica da Expressão Gênica , Técnicas de Silenciamento de Genes , Histona-Lisina N-Metiltransferase/química , Histona-Lisina N-Metiltransferase/genética , Histonas , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Camundongos , Ligação Proteica , Domínios Proteicos , Estabilidade Proteica , Transcrição GênicaRESUMO
R-2-hydroxyglutarate (R-2HG), a metabolite produced by mutant isocitrate dehydrogenases (IDHs), was recently reported to exhibit anti-tumor activity. However, its effect on cancer metabolism remains largely elusive. Here we show that R-2HG effectively attenuates aerobic glycolysis, a hallmark of cancer metabolism, in (R-2HG-sensitive) leukemia cells. Mechanistically, R-2HG abrogates fat-mass- and obesity-associated protein (FTO)/N6-methyladenosine (m6A)/YTH N6-methyladenosine RNA binding protein 2 (YTHDF2)-mediated post-transcriptional upregulation of phosphofructokinase platelet (PFKP) and lactate dehydrogenase B (LDHB) (two critical glycolytic genes) expression and thereby suppresses aerobic glycolysis. Knockdown of FTO, PFKP, or LDHB recapitulates R-2HG-induced glycolytic inhibition in (R-2HG-sensitive) leukemia cells, but not in normal CD34+ hematopoietic stem/progenitor cells, and inhibits leukemogenesis in vivo; conversely, their overexpression reverses R-2HG-induced effects. R-2HG also suppresses glycolysis and downregulates FTO/PFKP/LDHB expression in human primary IDH-wild-type acute myeloid leukemia (AML) cells, demonstrating the clinical relevance. Collectively, our study reveals previously unrecognized effects of R-2HG and RNA modification on aerobic glycolysis in leukemia, highlighting the therapeutic potential of targeting cancer epitranscriptomics and metabolism.
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Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Antineoplásicos/farmacologia , Glutaratos/farmacologia , Glicólise/genética , Lactato Desidrogenases/genética , Leucemia Mieloide Aguda/tratamento farmacológico , Fosfofrutoquinase-1 Tipo C/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/antagonistas & inibidores , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica , Glicólise/efeitos dos fármacos , Células HEK293 , Humanos , Células K562 , Lactato Desidrogenases/antagonistas & inibidores , Lactato Desidrogenases/metabolismo , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosforilação Oxidativa/efeitos dos fármacos , Fosfofrutoquinase-1 Tipo C/antagonistas & inibidores , Fosfofrutoquinase-1 Tipo C/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Análise de Sobrevida , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Chromosomal rearrangements of the mixed lineage leukemia (MLL) gene occur in â¼10% of B-cell acute lymphoblastic leukemia (B-ALL) and define a group of patients with dismal outcomes. Immunohistochemical staining of bone marrow biopsies from most of these patients revealed aberrant expression of BCL6, a transcription factor that promotes oncogenic B-cell transformation and drug resistance in B-ALL. Our genetic and ChIP-seq (chromatin immunoprecipitation [ChIP] combined with high-throughput sequencing) analyses showed that MLL-AF4 and MLL-ENL fusions directly bound to the BCL6 promoter and up-regulated BCL6 expression. While oncogenic MLL fusions strongly induced aberrant BCL6 expression in B-ALL cells, germline MLL was required to up-regulate Bcl6 in response to physiological stimuli during normal B-cell development. Inducible expression of Bcl6 increased MLL mRNA levels, which was reversed by genetic deletion and pharmacological inhibition of Bcl6, suggesting a positive feedback loop between MLL and BCL6. Highlighting the central role of BCL6 in MLL-rearranged B-ALL, conditional deletion and pharmacological inhibition of BCL6 compromised leukemogenesis in transplant recipient mice and restored sensitivity to vincristine chemotherapy in MLL-rearranged B-ALL patient samples. Oncogenic MLL fusions strongly induced transcriptional activation of the proapoptotic BH3-only molecule BIM, while BCL6 was required to curb MLL-induced expression of BIM. Notably, peptide (RI-BPI) and small molecule (FX1) BCL6 inhibitors derepressed BIM and synergized with the BH3-mimetic ABT-199 in eradicating MLL-rearranged B-ALL cells. These findings uncover MLL-dependent transcriptional activation of BCL6 as a previously unrecognized requirement of malignant transformation by oncogenic MLL fusions and identified BCL6 as a novel target for the treatment of MLL-rearranged B-ALL.
Assuntos
Regulação Leucêmica da Expressão Gênica , Proteína de Leucina Linfoide-Mieloide/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/fisiopatologia , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Animais , Biomarcadores Tumorais/genética , Sobrevivência Celular/genética , Células Cultivadas , Deleção de Genes , Marcação de Genes , Humanos , Camundongos , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Prognóstico , Regiões Promotoras Genéticas/genéticaRESUMO
Interferon-induced transmembrane protein 3 (IFITM3) has previously been identified as an endosomal protein that blocks viral infection1-3. Here we studied clinical cohorts of patients with B cell leukaemia and lymphoma, and identified IFITM3 as a strong predictor of poor outcome. In normal resting B cells, IFITM3 was minimally expressed and mainly localized in endosomes. However, engagement of the B cell receptor (BCR) induced both expression of IFITM3 and phosphorylation of this protein at Tyr20, which resulted in the accumulation of IFITM3 at the cell surface. In B cell leukaemia, oncogenic kinases phosphorylate IFITM3 at Tyr20, which causes constitutive localization of this protein at the plasma membrane. In a mouse model, Ifitm3-/- naive B cells developed in normal numbers; however, the formation of germinal centres and the production of antigen-specific antibodies were compromised. Oncogenes that induce the development of leukaemia and lymphoma did not transform Ifitm3-/- B cells. Conversely, the phosphomimetic IFITM3(Y20E) mutant induced oncogenic PI3K signalling and initiated the transformation of premalignant B cells. Mechanistic experiments revealed that IFITM3 functions as a PIP3 scaffold and central amplifier of PI3K signalling. The amplification of PI3K signals depends on IFITM3 using two lysine residues (Lys83 and Lys104) in its conserved intracellular loop as a scaffold for the accumulation of PIP3. In Ifitm3-/- B cells, lipid rafts were depleted of PIP3, which resulted in the defective expression of over 60 lipid-raft-associated surface receptors, and impaired BCR signalling and cellular adhesion. We conclude that the phosphorylation of IFITM3 that occurs after B cells encounter antigen induces a dynamic switch from antiviral effector functions in endosomes to a PI3K amplification loop at the cell surface. IFITM3-dependent amplification of PI3K signalling, which in part acts downstream of the BCR, is critical for the rapid expansion of B cells with high affinity to antigen. In addition, multiple oncogenes depend on IFITM3 to assemble PIP3-dependent signalling complexes and amplify PI3K signalling for malignant transformation.
Assuntos
Linfócitos B/metabolismo , Proteínas de Membrana/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Animais , Antígenos CD19/metabolismo , Linfócitos B/enzimologia , Linfócitos B/imunologia , Linfócitos B/patologia , Transformação Celular Neoplásica , Feminino , Centro Germinativo/citologia , Centro Germinativo/imunologia , Centro Germinativo/patologia , Humanos , Integrinas/metabolismo , Microdomínios da Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Modelos Moleculares , Fosforilação , Receptores de Antígenos de Linfócitos B/metabolismoRESUMO
Malignant transformation of cells typically involves several genetic lesions, whose combined activity gives rise to cancer1. Here we analyse 1,148 patient-derived B-cell leukaemia (B-ALL) samples, and find that individual mutations do not promote leukaemogenesis unless they converge on one single oncogenic pathway that is characteristic of the differentiation stage of transformed B cells. Mutations that are not aligned with this central oncogenic driver activate divergent pathways and subvert transformation. Oncogenic lesions in B-ALL frequently mimic signalling through cytokine receptors at the pro-B-cell stage (via activation of the signal-transduction protein STAT5)2-4 or pre-B-cell receptors in more mature cells (via activation of the protein kinase ERK)5-8. STAT5- and ERK-activating lesions are found frequently, but occur together in only around 3% of cases (P = 2.2 × 10-16). Single-cell mutation and phospho-protein analyses reveal the segregation of oncogenic STAT5 and ERK activation to competing clones. STAT5 and ERK engage opposing biochemical and transcriptional programs that are orchestrated by the transcription factors MYC and BCL6, respectively. Genetic reactivation of the divergent (suppressed) pathway comes at the expense of the principal oncogenic driver and reverses transformation. Conversely, deletion of divergent pathway components accelerates leukaemogenesis. Thus, persistence of divergent signalling pathways represents a powerful barrier to transformation, while convergence on one principal driver defines a central event in leukaemia initiation. Pharmacological reactivation of suppressed divergent circuits synergizes strongly with inhibition of the principal oncogenic driver. Hence, reactivation of divergent pathways can be leveraged as a previously unrecognized strategy to enhance treatment responses.
Assuntos
Linfócitos B/citologia , Linfócitos B/metabolismo , Transformação Celular Neoplásica , Leucemia de Células B/metabolismo , Leucemia de Células B/patologia , Transdução de Sinais , Animais , Linfócitos B/patologia , Linhagem Celular Tumoral , Ativação Enzimática , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Humanos , Camundongos , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Fator de Transcrição STAT5/metabolismoRESUMO
High-power fiber laser amplifiers have enabled an increasing range of applications in industry, science, and defense. The power scaling for fiber amplifiers is currently limited by transverse mode instability. Most techniques for suppressing the instability are based on single- or few-mode fibers in order to output a clean collimated beam. Here, we study theoretically using a highly multimode fiber amplifier with many-mode excitation for efficient suppression of thermo-optical nonlinearity and instability. We find that the mismatch of characteristic length scales between temperature and optical intensity variations across the fiber generically leads to weaker thermo-optical coupling between fiber modes. Consequently, the transverse mode instability (TMI) threshold power increases linearly with the number of equally excited modes. When the frequency bandwidth of a coherent seed laser is narrower than the spectral correlation width of the multimode fiber, the amplified light maintains high spatial coherence and can be transformed to any target pattern or focused to a diffraction-limited spot by a spatial mask at either the input or output end of the amplifier. Our method simultaneously achieves high average power, narrow spectral width, and good beam quality, which are required for fiber amplifiers in various applications.
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Gene editing in the brain has been challenging because of the restricted transport imposed by the blood-brain barrier (BBB). Current approaches mainly rely on local injection to bypass the BBB. However, such administration is highly invasive and not amenable to treating certain delicate regions of the brain. We demonstrate a safe and effective gene editing technique by using focused ultrasound (FUS) to transiently open the BBB for the transport of intravenously delivered CRISPR/Cas9 machinery to the brain.
Assuntos
Encéfalo , Edição de Genes , Encéfalo/diagnóstico por imagem , Barreira Hematoencefálica , Transporte Biológico , MicrobolhasRESUMO
Recently, extracting inherent biological system information (e.g. cellular networks) from genome-wide expression profiles for developing personalized diagnostic and therapeutic strategies has become increasingly important. However, accurately constructing single-sample networks (SINs) to capture individual characteristics and heterogeneity in disease remains challenging. Here, we propose a sample-specific-weighted correlation network (SWEET) method to model SINs by integrating the genome-wide sample-to-sample correlation (i.e. sample weights) with the differential network between perturbed and aggregate networks. For a group of samples, the genome-wide sample weights can be assessed without prior knowledge of intrinsic subpopulations to address the network edge number bias caused by sample size differences. Compared with the state-of-the-art SIN inference methods, the SWEET SINs in 16 cancers more likely fit the scale-free property, display higher overlap with the human interactomes and perform better in identifying three types of cancer-related genes. Moreover, integrating SWEET SINs with a network proximity measure facilitates characterizing individual features and therapy in diseases, such as somatic mutation, mut-driver and essential genes. Biological experiments further validated two candidate repurposable drugs, albendazole for head and neck squamous cell carcinoma (HNSCC) and lung adenocarcinoma (LUAD) and encorafenib for HNSCC. By applying SWEET, we also identified two possible LUAD subtypes that exhibit distinct clinical features and molecular mechanisms. Overall, the SWEET method complements current SIN inference and analysis methods and presents a view of biological systems at the network level to offer numerous clues for further investigation and clinical translation in network medicine and precision medicine.
Assuntos
Redes Reguladoras de Genes , Neoplasias de Cabeça e Pescoço , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Oncogenes , Neoplasias de Cabeça e Pescoço/genéticaRESUMO
Abrupt changes in system states and dynamical behaviors are often observed in natural systems; such phenomena, named regime shifts, are explained as transitions between alternative steady states (more generally, attractors). Various methods have been proposed to detect regime shifts from time series data, but a generic detection method with theoretical linkage to underlying dynamics is lacking. Here, we provide a novel method named Nested-Library Analysis (NLA) to retrospectively detect regime shifts using empirical dynamic modeling (EDM) rooted in theory of attractor reconstruction. Specifically, NLA determines the time of regime shift as the cutting point at which sequential reduction of the library set (i.e., the time series data used to reconstruct the attractor for forecasting) optimizes the forecast skill of EDM. We illustrate this method on a chaotic model of which changing parameters present a critical transition. Our analysis shows that NLA detects the change point in the model system and outperforms existing approaches based on statistical characteristics. In addition, NLA empirically detected a real-world regime shift event revealing an abrupt change of Pacific Decadal Oscillation index around the mid-1970s. Importantly, our method can be easily generalized to various systems because NLA is equation-free and requires only a single time series.
Assuntos
Dinâmica não Linear , Estudos RetrospectivosRESUMO
SF3B1 is the most commonly mutated RNA splicing factor in cancer1-4, but the mechanisms by which SF3B1 mutations promote malignancy are poorly understood. Here we integrated pan-cancer splicing analyses with a positive-enrichment CRISPR screen to prioritize splicing alterations that promote tumorigenesis. We report that diverse SF3B1 mutations converge on repression of BRD9, which is a core component of the recently described non-canonical BAF chromatin-remodelling complex that also contains GLTSCR1 and GLTSCR1L5-7. Mutant SF3B1 recognizes an aberrant, deep intronic branchpoint within BRD9 and thereby induces the inclusion of a poison exon that is derived from an endogenous retroviral element and subsequent degradation of BRD9 mRNA. Depletion of BRD9 causes the loss of non-canonical BAF at CTCF-associated loci and promotes melanomagenesis. BRD9 is a potent tumour suppressor in uveal melanoma, such that correcting mis-splicing of BRD9 in SF3B1-mutant cells using antisense oligonucleotides or CRISPR-directed mutagenesis suppresses tumour growth. Our results implicate the disruption of non-canonical BAF in the diverse cancer types that carry SF3B1 mutations and suggest a mechanism-based therapeutic approach for treating these malignancies.
Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Neoplasias/genética , Splicing de RNA , Spliceossomos/metabolismo , Animais , Linhagem Celular Tumoral , Montagem e Desmontagem da Cromatina/genética , Proteínas Cromossômicas não Histona/genética , Humanos , Camundongos , Transplante de Neoplasias , Neoplasias/patologia , Fosfoproteínas/metabolismo , Fatores de Processamento de RNA/metabolismo , Spliceossomos/genética , Fatores de Transcrição/metabolismoRESUMO
Transcription and pre-mRNA splicing are key steps in the control of gene expression and mutations in genes regulating each of these processes are common in leukaemia1,2. Despite the frequent overlap of mutations affecting epigenetic regulation and splicing in leukaemia, how these processes influence one another to promote leukaemogenesis is not understood and, to our knowledge, there is no functional evidence that mutations in RNA splicing factors initiate leukaemia. Here, through analyses of transcriptomes from 982 patients with acute myeloid leukaemia, we identified frequent overlap of mutations in IDH2 and SRSF2 that together promote leukaemogenesis through coordinated effects on the epigenome and RNA splicing. Whereas mutations in either IDH2 or SRSF2 imparted distinct splicing changes, co-expression of mutant IDH2 altered the splicing effects of mutant SRSF2 and resulted in more profound splicing changes than either mutation alone. Consistent with this, co-expression of mutant IDH2 and SRSF2 resulted in lethal myelodysplasia with proliferative features in vivo and enhanced self-renewal in a manner not observed with either mutation alone. IDH2 and SRSF2 double-mutant cells exhibited aberrant splicing and reduced expression of INTS3, a member of the integrator complex3, concordant with increased stalling of RNA polymerase II (RNAPII). Aberrant INTS3 splicing contributed to leukaemogenesis in concert with mutant IDH2 and was dependent on mutant SRSF2 binding to cis elements in INTS3 mRNA and increased DNA methylation of INTS3. These data identify a pathogenic crosstalk between altered epigenetic state and splicing in a subset of leukaemias, provide functional evidence that mutations in splicing factors drive myeloid malignancy development, and identify spliceosomal changes as a mediator of IDH2-mutant leukaemogenesis.
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Processamento Alternativo/genética , Carcinogênese/genética , Epigênese Genética , Leucemia Mieloide Aguda/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células , Metilação de DNA , Proteínas de Ligação a DNA/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Isocitrato Desidrogenase/genética , Masculino , Mutação/genética , RNA Polimerase II/metabolismo , Fatores de Processamento de Serina-Arginina/genética , TranscriptomaRESUMO
Enhancer activation is a critical step for gene activation. Here we report an epigenetic crosstalk at enhancers between the UTX (H3K27 demethylase)-MLL4 (H3K4 methyltransferase) complex and the histone acetyltransferase p300. We demonstrate that UTX, in a demethylase activity-independent manner, facilitates conversion of inactive enhancers in embryonic stem cells to an active (H3K4me1+/H3K27ac+) state by recruiting and coupling the enzymatic functions of MLL4 and p300. Loss of UTX leads to attenuated enhancer activity, characterized by reduced levels of H3K4me1 and H3K27ac as well as impaired transcription. The UTX-MLL4 complex enhances p300-dependent H3K27 acetylation through UTX-dependent stimulation of p300 recruitment, while MLL4-mediated H3K4 monomethylation, reciprocally, requires p300 function. Importantly, MLL4-generated H3K4me1 further enhances p300-dependent transcription. This work reveals a previously unrecognized cooperativity among enhancer-associated chromatin modulators, including a unique function for UTX, in establishing an "active enhancer landscape" and defines a detailed mechanism for the joint deposition of H3K4me1 and H3K27ac.
Assuntos
Cromatina/metabolismo , Proteína p300 Associada a E1A/metabolismo , Células-Tronco Embrionárias/enzimologia , Elementos Facilitadores Genéticos , Histona Desmetilases/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Transcrição Gênica , Ativação Transcricional , Animais , Cromatina/genética , Montagem e Desmontagem da Cromatina , Proteína p300 Associada a E1A/genética , Retroalimentação Fisiológica , Redes Reguladoras de Genes , Células HEK293 , Histona Desmetilases/genética , Histona-Lisina N-Metiltransferase/genética , Histonas/metabolismo , Humanos , Masculino , Metilação , Camundongos , Interferência de RNA , TransfecçãoRESUMO
We reconstitute a phosphotyrosine-mediated protein condensation phase transition of the â¼200 residue cytoplasmic tail of the epidermal growth factor receptor (EGFR) and the adaptor protein, Grb2, on a membrane surface. The phase transition depends on phosphorylation of the EGFR tail, which recruits Grb2, and crosslinking through a Grb2-Grb2 binding interface. The Grb2 Y160 residue plays a structurally critical role in the Grb2-Grb2 interaction, and phosphorylation or mutation of Y160 prevents EGFR:Grb2 condensation. By extending the reconstitution experiment to include the guanine nucleotide exchange factor, SOS, and its substrate Ras, we further find that the condensation state of the EGFR tail controls the ability of SOS, recruited via Grb2, to activate Ras. These results identify an EGFR:Grb2 protein condensation phase transition as a regulator of signal propagation from EGFR to the MAPK pathway.
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Receptores ErbB , Transdução de Sinais , Receptores ErbB/metabolismo , Proteína Adaptadora GRB2/metabolismo , Fosforilação , Fosfotirosina/metabolismoRESUMO
Ferroelectric catalysts are known for altering surface catalytic activities by changing the direction of their electric polarizations. This study demonstrates polarization-switchable electrochemistry using layered bismuth oxyselenide (L-Bi2O2Se) bifunctional microreactors through ferroelectric modulation. A selective-area ionic liquid gating is developed with precise control over the spatial distribution of the dipole orientation of L-Bi2O2Se. On-chip microreactors with upward polarization favor the oxygen evolution reaction, whereas those with downward polarization prefer the hydrogen evolution reaction. The microscopic origin behind polarization-switchable electrochemistry primarily stems from enhanced surface adsorption and reduced energy barriers for reactions, as examined by nanoscale scanning electrochemical cell microscopy. Integrating a pair of L-Bi2O2Se microreactors consisting of upward or downward polarizations demonstrates overall water splitting in a full-cell configuration based on a bifunctional catalyst. The ability to modulate surface polarizations on a single catalyst via ferroelectric polarization switching offers a pathway for designing catalysts for water splitting.
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This research explores the role of microRNA in senescence of human endothelial progenitor cells (EPCs) induced by replication. Hsa-miR-134-5p was found up-regulated in senescent EPCs where overexpression improved angiogenic activity. Hsa-miR-134-5p, which targeted transforming growth factor ß-activated kinase 1-binding protein 1 (TAB1) gene, down-regulated TAB1 protein, and inhibited phosphorylation of p38 mitogen-activated protein kinase (p38) in hsa-miR-134-5p-overexpressed senescent EPCs. Treatment with siRNA specific to TAB1 (TAB1si) down-regulated TAB1 protein and subsequently inhibited p38 activation in senescent EPCs. Treatment with TAB1si and p38 inhibitor, respectively, showed angiogenic improvement. In parallel, transforming growth factor Beta 1 (TGF-ß1) was down-regulated in hsa-miR-134-5p-overexpressed senescent EPCs and addition of TGF-ß1 suppressed the angiogenic improvement. Analysis of peripheral blood mononuclear cells (PBMCs) disclosed expression levels of hsa-miR-134-5p altered in adult life, reaching a peak before 65 years, and then falling in advanced age. Calculation of the Framingham risk score showed the score inversely correlates with the hsa-miR-134-5p expression level. In summary, hsa-miR-134-5p is involved in the regulation of senescence-related change of angiogenic activity via TAB1-p38 signalling and via TGF-ß1 reduction. Hsa-miR-134-5p has a potential cellular rejuvenation effect in human senescent EPCs. Detection of human PBMC-derived hsa-miR-134-5p predicts cardiovascular risk.
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Proteínas Adaptadoras de Transdução de Sinal , Doenças Cardiovasculares , Senescência Celular , Células Progenitoras Endoteliais , Leucócitos Mononucleares , MicroRNAs , Proteínas Quinases p38 Ativadas por Mitógeno , MicroRNAs/genética , MicroRNAs/metabolismo , Humanos , Células Progenitoras Endoteliais/metabolismo , Senescência Celular/genética , Leucócitos Mononucleares/metabolismo , Pessoa de Meia-Idade , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Masculino , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/patologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Feminino , Idoso , Neovascularização Fisiológica/genética , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta1/genética , Adulto , Fatores de RiscoRESUMO
Manipulating electronic polarizations such as ferroelectric or spin polarizations has recently emerged as an effective strategy for enhancing the efficiency of photocatalytic reactions. This study demonstrates the control of electronic polarizations modulated by ferroelectric and magnetic approaches within a two-dimensional (2D) layered crystal of copper indium thiophosphate (CuInP2S6) to boost the photocatalytic reduction of CO2. We investigate the substantial influence of ferroelectric polarization on the photocatalytic CO2 reduction efficiency, utilizing the ferroelectric-paraelectric phase transition and polarization alignment through electrical poling. Additionally, we explore enhancing the CO2 reduction efficiency by harnessing spin electrons through the synergistic introduction of sulfur vacancies and applying a magnetic field. Several advanced characterization techniques, including piezoresponse force microscopy, ultrafast pump-probe spectroscopy, in situ X-ray absorption spectroscopy, and in situ diffuse reflectance infrared Fourier transformed spectroscopy, are performed to unveil the underlying mechanism of the enhanced photocatalytic CO2 reduction. These findings pave the way for manipulating electronic polarizations regulated through ferroelectric or magnetic modulations in 2D layered materials to advance the efficiency of photocatalytic CO2 reduction.
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Retinitis pigmentosa (RP) is caused by one of many possible gene mutations. The National Institutes of Health recommends high daily doses of vitamin A palmitate for RP patients. There is a critical knowledge gap surrounding the therapeutic applicability of vitamin A to patients with the different subtypes of the disease. Here, we present a case report of a patient with RP caused by a p.D190N mutation in Rhodopsin (RHO) associated with abnormally high quantitative autofluorescence values after long-term vitamin A supplementation. We investigated the effects of vitamin A treatment strategy on RP caused by the p.D190N mutation in RHO by exposing Rhodopsin p.D190N (RhoD190N/+) and wild-type (WT) mice to experimental vitamin A-supplemented and standard control diets. The patient's case suggests that the vitamin A treatment strategy should be further studied to determine its effect on RP caused by p.D190N mutation in RHO and other mutations. Our mouse experiments revealed that RhoD190N/+ mice on the vitamin A diet exhibited higher levels of autofluorescence and lipofuscin metabolites compared to WT mice on the same diet and isogenic controls on the standard control diet. Vitamin A supplementation diminished photoreceptor function in RhoD190N/+ mice while preserving cone response in WT mice. Our findings highlight the importance of more investigations into the efficacy of clinical treatments like vitamin A for patients with certain genetic subtypes of disease and of genotyping in the precision care of inherited retinal degenerations.
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Degeneração Retiniana , Retinose Pigmentar , Animais , Suplementos Nutricionais , Camundongos , Mutação , Degeneração Retiniana/genética , Retinose Pigmentar/tratamento farmacológico , Retinose Pigmentar/genética , Retinose Pigmentar/metabolismo , Rodopsina/genética , Rodopsina/metabolismo , Vitamina ARESUMO
BACKGROUND & AIMS: Ultra-processed foods (UPFs) may have a negative impact on bowel habits. We aimed to assess the association between UPF and unprocessed or minimally processed food (MPF) intake and bowel habits among adults in the United States (U.S.). METHODS: We performed a cross-sectional study using data from the National Health and Nutrition Examination Survey (2005-2010). We used two 24-hour dietary recalls and, based on the Nova classification, calculated intakes of UPFs and MPFs. Constipation and diarrhea were defined using the Bristol Stool Form Scale and stool frequency. We performed survey-weighted logistic regression and substitution analysis to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Among 12,716 U.S. adults, there were 1290 cases of constipation and 1067 cases of diarrhea. Median UPF and MPF intakes were 26.5% and 66.2% of total grams per day, respectively. Greater UPF consumption (in % gram/d) was associated with higher odds of constipation (adjusted OR [aORQ4 vs Q1], 2.20; 95% CI, 1.76-2.74) (Ptrend < .001) but not diarrhea (aORQ4 vs Q1, 0.82; 95% CI, 0.62-1.09) (Ptrend = .12). Increased MPF consumption was associated with lower odds of constipation (aORQ4 vs Q1, 0.46; 95% CI, 0.370-0.57) (Ptrend < .001). Associations with constipation were attenuated after adjusting for diet quality (aORQ4 vs Q1, UPF, 1.53; MPF, 0.69). Substituting 10% of UPF intake with an equivalent proportion of MPFs was associated with lower odds of constipation (aOR, 0.90; 95% CI, 0.87-0.93). CONCLUSIONS: UPF intake was associated with higher odds of constipation, whereas the odds were lower with greater MPF consumption. The effect of food processing on bowel habits was independent of diet quality.
RESUMO
In mice, the entry of germ cells into meiosis crucially depends on the expression of stimulated by retinoic acid gene 8 (Stra8). Stra8 is expressed specifically in pre-meiotic germ cells of females and males, at fetal and postnatal stages, respectively, but the mechanistic details of its spatiotemporal regulation are yet to be defined. In particular, there has been considerable debate regarding whether retinoic acid is required, in vivo, to initiate Stra8 expression in the mouse fetal ovary. We show that the distinctive anterior-to-posterior pattern of Stra8 initiation, characteristic of germ cells in the fetal ovary, is faithfully recapitulated when 2.9â kb of the Stra8 promoter is used to drive eGFP expression. Using in vitro transfection assays of cutdown and mutant constructs, we identified two functional retinoic acid responsive elements (RAREs) within this 2.9â kb regulatory element. We also show that the transcription factor DMRT1 enhances Stra8 expression, but only in the presence of RA and the most proximal RARE. Finally, we used CRISPR/Cas9-mediated targeted mutation studies to demonstrate that both RAREs are required for optimal Stra8 expression levels in vivo.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Células Germinativas/metabolismo , Sequências Reguladoras de Ácido Nucleico/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Sítios de Ligação , Sistemas CRISPR-Cas/genética , Feminino , Desenvolvimento Fetal/genética , Feto/citologia , Feto/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Células Germinativas/citologia , Meiose , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutagênese , Ovário/citologia , Ovário/metabolismo , Regiões Promotoras Genéticas , Receptores X de Retinoides/genética , Receptores X de Retinoides/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/farmacologia , Tretinoína/farmacologiaRESUMO
High-entropy oxides (HEOs) are promising anode materials for lithium-ion batteries (LIBs), owing to their stable crystal structure, superionic conductivity, and high capacity. In this study, the (Cr, Mn, Fe, Co, and Ni)3O4 HEO via solid-state reaction is prepared. To improve the synthetic efficiency, it is necessary to understand the formation mechanism. Therefore, a high-resolution transmission electron microscopy (HRTEM) is used to record information during calcination at increasing temperature. The overall formation process included MnO2 and NiO aggregation at 500 °C, followed by (Mn, and Ni)3O4 combined with Co3O4 at 600 °C to form (Mn, Co, and Ni)3O4. At higher temperatures, Fe2O3 and Cr2O3 sequentially combined with (Mn, Co, and Ni)3O4 and formed the (Cr, Mn, Fe, Co, Ni)3O4 at 900 °C. In addition, the valence-state-changing mechanisms and ion arrangements of (Cr, Mn, Fe, Co, and Ni)3O4 are determined using electron energy loss spectroscopy (EELS) and extended X-ray absorption fine structure (EXAFS). This study successfully revealed the formation of HEO at atomic scale. The results provide valuable insights for improving the manufacturing process of (Cr, Mn, Fe, Co, and Ni)3O4 HEOs, which is expected to play a vital role in the development of anode materials for next-generation LIBs.