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1.
Cell ; 167(2): 405-418.e13, 2016 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-27693350

RESUMO

The HVEM (TNFRSF14) receptor gene is among the most frequently mutated genes in germinal center lymphomas. We report that loss of HVEM leads to cell-autonomous activation of B cell proliferation and drives the development of GC lymphomas in vivo. HVEM-deficient lymphoma B cells also induce a tumor-supportive microenvironment marked by exacerbated lymphoid stroma activation and increased recruitment of T follicular helper (TFH) cells. These changes result from the disruption of inhibitory cell-cell interactions between the HVEM and BTLA (B and T lymphocyte attenuator) receptors. Accordingly, administration of the HVEM ectodomain protein (solHVEM(P37-V202)) binds BTLA and restores tumor suppression. To deliver solHVEM to lymphomas in vivo, we engineered CD19-targeted chimeric antigen receptor (CAR) T cells that produce solHVEM locally and continuously. These modified CAR-T cells show enhanced therapeutic activity against xenografted lymphomas. Hence, the HVEM-BTLA axis opposes lymphoma development, and our study illustrates the use of CAR-T cells as "micro-pharmacies" able to deliver an anti-cancer protein.


Assuntos
Transferência Adotiva/métodos , Linfoma Folicular/terapia , Receptores Imunológicos/metabolismo , Membro 14 de Receptores do Fator de Necrose Tumoral/genética , Linfócitos T/imunologia , Proteínas Supressoras de Tumor/genética , Animais , Antígenos CD19/imunologia , Linfócitos B/imunologia , Proliferação de Células , Humanos , Ativação Linfocitária , Linfoma Folicular/genética , Camundongos , Neoplasias Experimentais/genética , Neoplasias Experimentais/terapia , Domínios Proteicos , Engenharia de Proteínas , Membro 14 de Receptores do Fator de Necrose Tumoral/química , Membro 14 de Receptores do Fator de Necrose Tumoral/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Microambiente Tumoral , Proteínas Supressoras de Tumor/química , Proteínas Supressoras de Tumor/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Nature ; 623(7988): 772-781, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37968388

RESUMO

Mouse models are a critical tool for studying human diseases, particularly developmental disorders1. However, conventional approaches for phenotyping may fail to detect subtle defects throughout the developing mouse2. Here we set out to establish single-cell RNA sequencing of the whole embryo as a scalable platform for the systematic phenotyping of mouse genetic models. We applied combinatorial indexing-based single-cell RNA sequencing3 to profile 101 embryos of 22 mutant and 4 wild-type genotypes at embryonic day 13.5, altogether profiling more than 1.6 million nuclei. The 22 mutants represent a range of anticipated phenotypic severities, from established multisystem disorders to deletions of individual regulatory regions4,5. We developed and applied several analytical frameworks for detecting differences in composition and/or gene expression across 52 cell types or trajectories. Some mutants exhibit changes in dozens of trajectories whereas others exhibit changes in only a few cell types. We also identify differences between widely used wild-type strains, compare phenotyping of gain- versus loss-of-function mutants and characterize deletions of topological associating domain boundaries. Notably, some changes are shared among mutants, suggesting that developmental pleiotropy might be 'decomposable' through further scaling of this approach. Overall, our findings show how single-cell profiling of whole embryos can enable the systematic molecular and cellular phenotypic characterization of mouse mutants with unprecedented breadth and resolution.


Assuntos
Deficiências do Desenvolvimento , Embrião de Mamíferos , Mutação , Fenótipo , Análise da Expressão Gênica de Célula Única , Animais , Camundongos , Núcleo Celular/genética , Deficiências do Desenvolvimento/genética , Deficiências do Desenvolvimento/patologia , Embrião de Mamíferos/metabolismo , Embrião de Mamíferos/patologia , Mutação com Ganho de Função , Genótipo , Mutação com Perda de Função , Modelos Genéticos , Modelos Animais de Doenças
3.
Mol Cell ; 81(10): 2094-2111.e9, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-33878293

RESUMO

Even though SYK and ZAP70 kinases share high sequence homology and serve analogous functions, their expression in B and T cells is strictly segregated throughout evolution. Here, we identified aberrant ZAP70 expression as a common feature in a broad range of B cell malignancies. We validated SYK as the kinase that sets the thresholds for negative selection of autoreactive and premalignant clones. When aberrantly expressed in B cells, ZAP70 competes with SYK at the BCR signalosome and redirects SYK from negative selection to tonic PI3K signaling, thereby promoting B cell survival. In genetic mouse models for B-ALL and B-CLL, conditional expression of Zap70 accelerated disease onset, while genetic deletion impaired malignant transformation. Inducible activation of Zap70 during B cell development compromised negative selection of autoreactive B cells, resulting in pervasive autoantibody production. Strict segregation of the two kinases is critical for normal B cell selection and represents a central safeguard against the development of autoimmune disease and B cell malignancies.


Assuntos
Autoimunidade , Neoplasias/enzimologia , Neoplasias/prevenção & controle , Quinase Syk/metabolismo , Proteína-Tirosina Quinase ZAP-70/metabolismo , Animais , Antígenos CD19/metabolismo , Linfócitos B , Cálcio/metabolismo , Diferenciação Celular , Transformação Celular Neoplásica , Ativação Enzimática , Humanos , Tolerância Imunológica , Linfoma de Células B/enzimologia , Linfoma de Células B/patologia , Camundongos , Modelos Genéticos , Fatores de Transcrição NFATC/metabolismo , Proteínas de Neoplasias , Fosfatidilinositol 3-Quinases/metabolismo , Ligação Proteica , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais
4.
Genome Res ; 34(4): 556-571, 2024 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-38719473

RESUMO

H3K9me3-dependent heterochromatin is critical for the silencing of repeat-rich pericentromeric regions and also has key roles in repressing lineage-inappropriate protein-coding genes in differentiation and development. Here, we investigate the molecular consequences of heterochromatin loss in cells deficient in both SUV39H1 and SUV39H2 (Suv39DKO), the major mammalian histone methyltransferase enzymes that catalyze heterochromatic H3K9me3 deposition. We reveal a paradoxical repression of protein-coding genes in Suv39DKO cells, with these differentially expressed genes principally in euchromatic (Tn5-accessible, H3K4me3- and H3K27ac-marked) rather than heterochromatic (H3K9me3-marked) or polycomb (H3K27me3-marked) regions. Examination of the three-dimensional (3D) nucleome reveals that transcriptomic dysregulation occurs in euchromatic regions close to the nuclear periphery in 3D space. Moreover, this transcriptomic dysregulation is highly correlated with altered 3D genome organization in Suv39DKO cells. Together, our results suggest that the nuclear lamina-tethering of Suv39-dependent H3K9me3 domains provides an essential scaffold to support euchromatic genome organization and the maintenance of gene transcription for healthy cellular function.


Assuntos
Eucromatina , Heterocromatina , Histona-Lisina N-Metiltransferase , Histonas , Metiltransferases , Transcrição Gênica , Animais , Camundongos , Linhagem Celular , Eucromatina/metabolismo , Eucromatina/genética , Regulação da Expressão Gênica , Heterocromatina/metabolismo , Heterocromatina/genética , Histona-Lisina N-Metiltransferase/metabolismo , Histona-Lisina N-Metiltransferase/genética , Histonas/metabolismo , Histonas/genética , Metiltransferases/metabolismo , Metiltransferases/genética , Proteínas Repressoras/metabolismo , Proteínas Repressoras/genética
5.
Immunity ; 49(3): 464-476.e4, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30193847

RESUMO

According to the established model of murine innate lymphoid cell (ILC) development, helper ILCs develop separately from natural killer (NK) cells. However, it is unclear how helper ILCs and NK cells develop in humans. Here we elucidated key steps of NK cell, ILC2, and ILC3 development within human tonsils using ex vivo molecular and functional profiling and lineage differentiation assays. We demonstrated that while tonsillar NK cells, ILC2s, and ILC3s originated from a common CD34-CD117+ ILC precursor pool, final steps of ILC2 development deviated independently and became mutually exclusive from those of NK cells and ILC3s, whose developmental pathways overlapped. Moreover, we identified a CD34-CD117+ ILC precursor population that expressed CD56 and gave rise to NK cells and ILC3s but not to ILC2s. These data support a model of human ILC development distinct from the mouse, whereby human NK cells and ILC3s share a common developmental pathway separate from ILC2s.


Assuntos
Células Matadoras Naturais/imunologia , Linfócitos/imunologia , Tonsila Palatina/imunologia , Animais , Antígenos CD34/metabolismo , Antígeno CD56/metabolismo , Diferenciação Celular , Linhagem da Célula , Células Cultivadas , Perfilação da Expressão Gênica , Humanos , Imunidade Inata , Ativação Linfocitária , Camundongos , Proteínas Proto-Oncogênicas c-kit/metabolismo
6.
Nature ; 592(7852): 93-98, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33568816

RESUMO

Long non-coding RNAs (lncRNAs) can be important components in gene-regulatory networks1, but the exact nature and extent of their involvement in human Mendelian disease is largely unknown. Here we show that genetic ablation of a lncRNA locus on human chromosome 2 causes a severe congenital limb malformation. We identified homozygous 27-63-kilobase deletions located 300 kilobases upstream of the engrailed-1 gene (EN1) in patients with a complex limb malformation featuring mesomelic shortening, syndactyly and ventral nails (dorsal dimelia). Re-engineering of the human deletions in mice resulted in a complete loss of En1 expression in the limb and a double dorsal-limb phenotype that recapitulates the human disease phenotype. Genome-wide transcriptome analysis in the developing mouse limb revealed a four-exon-long non-coding transcript within the deleted region, which we named Maenli. Functional dissection of the Maenli locus showed that its transcriptional activity is required for limb-specific En1 activation in cis, thereby fine-tuning the gene-regulatory networks controlling dorso-ventral polarity in the developing limb bud. Its loss results in the En1-related dorsal ventral limb phenotype, a subset of the full En1-associated phenotype. Our findings demonstrate that mutations involving lncRNA loci can result in human Mendelian disease.


Assuntos
Extremidades , Proteínas de Homeodomínio/genética , Deformidades Congênitas dos Membros/genética , RNA Longo não Codificante/genética , Deleção de Sequência/genética , Transcrição Gênica , Ativação Transcricional/genética , Animais , Linhagem Celular , Cromatina/genética , Modelos Animais de Doenças , Feminino , Humanos , Camundongos , Camundongos Transgênicos
7.
Blood ; 144(5): 525-540, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38701426

RESUMO

ABSTRACT: Rearrangements that place the oncogenes MYC, BCL2, or BCL6 adjacent to superenhancers are common in mature B-cell lymphomas. Lymphomas with diffuse large B-cell lymphoma (DLBCL) or high-grade morphology with both MYC and BCL2 rearrangements are classified as high-grade B-cell lymphoma with MYC and BCL2 rearrangements ("double hit"; HGBCL-DH-BCL2) and are associated with aggressive disease and poor outcomes. Although it is established that MYC rearrangements involving immunoglobulin (IG) loci are associated with inferior outcomes relative to those involving other non-IG superenhancers, the frequency of and mechanisms driving IG vs non-IG MYC rearrangements have not been elucidated. Here, we used custom targeted capture and/or whole-genome sequencing to characterize oncogene rearrangements across 883 mature B-cell lymphomas including Burkitt lymphoma, follicular lymphoma, DLBCL, and HGBCL-DH-BCL2 tumors. We demonstrate that, although BCL2 rearrangement topology is consistent across entities, HGBCL-DH-BCL2 have distinct MYC rearrangement architecture relative to tumors with single MYC rearrangements or with both MYC and BCL6 rearrangements (HGBCL-DH-BCL6), including both a higher frequency of non-IG rearrangements and different architecture of MYC::IGH rearrangements. The distinct MYC rearrangement patterns in HGBCL-DH-BCL2 occur on the background of high levels of somatic hypermutation across MYC partner loci in HGBCL-DH-BCL2, creating more opportunity to form these rearrangements. Furthermore, because 1 IGH allele is already disrupted by the existing BCL2 rearrangement, the MYC rearrangement architecture in HGBCL-DH-BCL2 likely reflects selective pressure to preserve both BCL2 and B-cell receptor expression. These data provide new mechanistic explanations for the distinct patterns of MYC rearrangements observed across different lymphoma entities.


Assuntos
Rearranjo Gênico , Proteínas Proto-Oncogênicas c-bcl-2 , Proteínas Proto-Oncogênicas c-myc , Humanos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-myc/genética , Linfoma de Células B/genética , Linfoma de Células B/patologia , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia
8.
Proc Natl Acad Sci U S A ; 120(36): e2301954120, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37639595

RESUMO

Accurate understanding of permafrost dynamics is critical for evaluating and mitigating impacts that may arise as permafrost degrades in the future; however, existing projections have large uncertainties. Studies of how permafrost responded historically during Earth's past warm periods are helpful in exploring potential future permafrost behavior and to evaluate the uncertainty of future permafrost change projections. Here, we combine a surface frost index model with outputs from the second phase of the Pliocene Model Intercomparison Project to simulate the near-surface (~3 to 4 m depth) permafrost state in the Northern Hemisphere during the mid-Pliocene warm period (mPWP, ~3.264 to 3.025 Ma). This period shares similarities with the projected future climate. Constrained by proxy-based surface air temperature records, our simulations demonstrate that near-surface permafrost was highly spatially restricted during the mPWP and was 93 ± 3% smaller than the preindustrial extent. Near-surface permafrost was present only in the eastern Siberian uplands, Canadian high Arctic Archipelago, and northernmost Greenland. The simulations are similar to near-surface permafrost changes projected for the end of this century under the SSP5-8.5 scenario and provide a perspective on the potential permafrost behavior that may be expected in a warmer world.

9.
Cancer Metastasis Rev ; 43(1): 379-391, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38319453

RESUMO

Intra-tumoural heterogeneity and cancer cell plasticity in colorectal cancer (CRC) have been key challenges to effective treatment for patients. It has been suggested that a subpopulation of LGR5-expressing cancer stem cells (CSCs) is responsible for driving tumour relapse and therapy resistance in CRC. However, studies have revealed that the LGR5+ve CSC population is highly sensitive to chemotherapy. It has been hypothesised that another subset of tumour cells can phenotypically revert to a stem-like state in response to chemotherapy treatment which replenishes the LGR5+ve CSC population and maintains tumour growth. Recently, a unique stem cell population marked by enriched clusterin (CLU) expression and termed the revival stem cell (RevSC) was identified in the regenerating murine intestine. This CLU-expressing cell population is quiescent during homeostasis but has the ability to survive and regenerate other stem cells upon injury. More recently, the CLU+ve signature has been implicated in several adverse outcomes in CRC, including chemotherapy resistance and poor patient survival; however, the mechanism behind this remains undetermined. In this review, we discuss recent insights on CLU in CRC and its roles in enhancing the plasticity of cells and further consider the implications of CLU as a prospective target for therapeutic intervention.


Assuntos
Neoplasias Colorretais , Resistencia a Medicamentos Antineoplásicos , Animais , Humanos , Clusterina/metabolismo , Neoplasias Colorretais/patologia , Células-Tronco Neoplásicas/patologia
10.
Blood ; 142(10): 887-902, 2023 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-37267517

RESUMO

Mantle cell lymphoma (MCL) is an incurable B-cell malignancy with an overall poor prognosis, particularly for patients that progress on targeted therapies. Novel, more durable treatment options are needed for patients with MCL. Protein arginine methyltransferase 5 (PRMT5) is overexpressed in MCL and plays an important oncogenic role in this disease via epigenetic and posttranslational modification of cell cycle regulators, DNA repair genes, components of prosurvival pathways, and RNA splicing regulators. The mechanism of targeting PRMT5 in MCL remains incompletely characterized. Here, we report on the antitumor activity of PRMT5 inhibition in MCL using integrated transcriptomics of in vitro and in vivo models of MCL. Treatment with a selective small-molecule inhibitor of PRMT5, PRT-382, led to growth arrest and cell death and provided a therapeutic benefit in xenografts derived from patients with MCL. Transcriptional reprograming upon PRMT5 inhibition led to restored regulatory activity of the cell cycle (p-RB/E2F), apoptotic cell death (p53-dependent/p53-independent), and activation of negative regulators of B-cell receptor-PI3K/AKT signaling (PHLDA3, PTPROt, and PIK3IP1). We propose pharmacologic inhibition of PRMT5 for patients with relapsed/refractory MCL and identify MTAP/CDKN2A deletion and wild-type TP53 as biomarkers that predict a favorable response. Selective targeting of PRMT5 has significant activity in preclinical models of MCL and warrants further investigation in clinical trials.


Assuntos
Linfoma de Célula do Manto , Fosfatidilinositol 3-Quinases , Adulto , Humanos , Linhagem Celular Tumoral , Linfoma de Célula do Manto/tratamento farmacológico , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/metabolismo
11.
Clin Immunol ; 265: 110297, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38909971

RESUMO

Activated B-cell-like diffuse large B-cell lymphoma (ABC-DLBCL) is an aggressive lymphoma characterized by constitutive NF-κB activation, but whether miR-17∼92 contributes to this activation remains unclear. Herein, we sought to evaluate the role of miR-17∼92 in the process of NF-κB activation in ABC-DLBCL. We found that the expression of miR-17∼92 primary transcript was positively correlated with NF-κB activity, miR-17∼92 activated the NF-κB signaling in ABC-DLBCL, and its over-expression promoted ABC-DLBCL cell growth, accelerated cell G1 to S phase transition and enhanced cell resistance to NF-κB inhibitor. Importantly, miR-17∼92 promoted NF-κB activation through directly targeting multiple ubiquitin-editing regulators to lead to increase the K63-linked polyubiquitination and decrease the K48-linked polyubiquitination of RIP1 complex in ABC-DLBCL. We further found that miR-17∼92 selectively activated IκB-α and NF-κB p65 but not NF-κB p52/p100, and high miR-17∼92 expression was also associated with poorer outcome in ABC-DLBCL patients. Overall, our results showed that miR-17∼92 selectively activated the canonical NF-κB signaling via targeting ubiquitin-editing regulators to lead to constitutively NF-κB activation and poorer outcome in ABC-DLBCL. These findings uncovered an innovative function of miR-17∼92 and previously unappreciated regulatory mechanism of NF-κB activation in ABC-DLBCL. Targeting miR-17∼92 may thus provide a novel bio-therapeutic strategy for ABC-DLBCL patients.


Assuntos
Linfoma Difuso de Grandes Células B , MicroRNAs , NF-kappa B , Ubiquitinação , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , NF-kappa B/metabolismo , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Linhagem Celular Tumoral , Transdução de Sinais , Masculino , Feminino , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Regulação Neoplásica da Expressão Gênica , Pessoa de Meia-Idade , Proliferação de Células/genética , RNA Longo não Codificante
12.
J Cell Sci ; 135(13)2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35635291

RESUMO

NFAT5 is the only known mammalian tonicity-responsive transcription factor with an essential role in cellular adaptation to hypertonic stress. It is also implicated in diverse physiological and pathological processes. NFAT5 activity is tightly regulated by extracellular tonicity, but the underlying mechanisms remain elusive. Here, we demonstrate that NFAT5 enters the nucleus via the nuclear pore complex. We found that NFAT5 utilizes a unique nuclear localization signal (NFAT5-NLS) for nuclear import. siRNA screening revealed that only karyopherin ß1 (KPNB1), but not karyopherin α, is responsible for the nuclear import of NFAT5 via direct interaction with the NFAT5-NLS. Proteomics analysis and siRNA screening further revealed that nuclear export of NFAT5 under hypotonicity is driven by exportin-T (XPOT), where the process requires RuvB-like AAA-type ATPase 2 (RUVBL2) as an indispensable chaperone. Our findings have identified an unconventional tonicity-dependent nucleocytoplasmic trafficking pathway for NFAT5 that represents a critical step in orchestrating rapid cellular adaptation to change in extracellular tonicity. These findings offer an opportunity for the development of novel NFAT5 targeting strategies that are potentially useful for the treatment of diseases associated with NFAT5 dysregulation.


Assuntos
Núcleo Celular , Carioferinas , ATPases Associadas a Diversas Atividades Celulares/genética , ATPases Associadas a Diversas Atividades Celulares/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Proteínas de Transporte/metabolismo , Núcleo Celular/metabolismo , DNA Helicases , Humanos , Carioferinas/metabolismo , Mamíferos/metabolismo , Sinais de Localização Nuclear/metabolismo , Proteínas de Transporte Nucleocitoplasmático , RNA Interferente Pequeno/metabolismo , Fatores de Transcrição/metabolismo , beta Carioferinas/genética , beta Carioferinas/metabolismo
13.
Oncologist ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38885304

RESUMO

BACKGROUND: Sarcopenia or skeletal muscle depletion is a poor prognostic factor for gastric cancer (GC). However, existing cutoff values of skeletal muscle index (SMI) for defining sarcopenia have been found to have limitations when clinically applied. This study aimed to determine the optimal cutoff for SMI to predict severe toxicities of chemotherapy and overall survival (OS) in patients with advanced GC. METHODS: Patients with metastatic gastric adenocarcinoma who received first-line palliative chemotherapy between January 2014 and December 2021 at Queen Mary Hospital, Hong Kong, were included in this study. The SMI was determined via a pre-chemotherapy computed tomography scan. Optimal cutoff points of SMI were identified by recursive partitioning analysis. Univariate and multivariate analyses evaluating risk factors of severe chemotherapy toxicities and OS were also performed. RESULTS: A total of 158 patients (male: 108 (68.4%), median age: 65.3) were included. The SMI cutoff to define low SMI was ≤33 cm2/m2 for males and ≤28 cm2/m2 for females; 30 patients (19.0%) had low SMI. Patients with low SMI had a higher incidence of hematological toxicities (63.3% vs 32.0%, P = .001) and non-hematological toxicities (66.7% vs 36.7%, P = .003). Multivariable analysis indicated that low SMI and low serum albumin (≤28 g/L) were independent predictive factors of hematological toxicity, while low SMI and neutrophil-lymphocyte ratio ≥5 were predictive factors of non-hematological toxicity. Moreover, patients with low SMI had a significantly shorter OS (P = .011), lower response rate to chemotherapy (P = .045), and lower utilization of subsequent lines of treatment (P < .001). CONCLUSIONS: Using pre-chemotherapy SMI cutoff (≤33 cm2/m2 for males and 28 cm2/m2 for females) one can identify individuals with a higher risk of severe chemotherapy toxicities and worse prognosis.

14.
New Phytol ; 243(6): 2130-2145, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39049585

RESUMO

Coral thermal bleaching resilience can be improved by enhancing photosymbiont thermal tolerance via experimental evolution. While successful for some strains, selection under stable temperatures was ineffective at increasing the thermal threshold of an already thermo-tolerant photosymbiont (Durusdinium trenchii). Corals from environments with fluctuating temperatures tend to have comparatively high heat tolerance. Therefore, we investigated whether exposure to temperature oscillations can raise the upper thermal limit of D. trenchii. We exposed a D. trenchii strain to stable and fluctuating temperature profiles, which varied in oscillation frequency. After 2.1 yr (54-73 generations), we characterised the adaptive responses under the various experimental evolution treatments by constructing thermal performance curves of growth from 21 to 31°C for the heat-evolved and wild-type lineages. Additionally, the accumulation of extracellular reactive oxygen species, photophysiology, photosynthesis and respiration rates were assessed under increasing temperatures. Of the fluctuating temperature profiles investigated, selection under the most frequent oscillations (diurnal) induced the greatest widening of D. trenchii's thermal niche. Continuous selection under elevated temperatures induced the only increase in thermal optimum and a degree of generalism. Our findings demonstrate how differing levels of thermal homogeneity during selection drive unique adaptive responses to heat in a coral photosymbiont.


Assuntos
Antozoários , Fotossíntese , Seleção Genética , Simbiose , Temperatura , Animais , Antozoários/fisiologia , Antozoários/efeitos da radiação , Simbiose/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Termotolerância/fisiologia
15.
Hepatology ; 78(5): 1569-1580, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37055020

RESUMO

BACKGROUND AND AIMS: Type 2 diabetes (T2D) and chronic hepatitis B infection (CHB) are risk factors of HCC. Sodium glucose co-transporter 2 inhibitors (SGLT2i) inhibit HCC oncogenesis in preclinical studies. However, clinical studies are lacking. This study aimed to evaluate the impact of SGLT2i use on incident HCC using a territory-wide cohort of exclusively patients with co-existing T2D and CHB. APPROACH AND RESULTS: Patients with co-existing T2D and CHB between 2015 and 2020 were identified from the representative electronic database of the Hong Kong Hospital Authority. Patients with and without SGLT2i use were 1:1 matched by propensity score for their demographics, biochemistry results, liver-related characteristics, and background medications. Cox proportional hazards regression model was used to assess the association between SGLT2i use and incident HCC. A total of 2,000 patients with co-existing T2D and CHB (1,000 in each SGLT2i and non-SGLT2i group; 79.7% on anti-HBV therapy at baseline) were included after propensity-score matching. Over a follow-up of 3,704 person-years, the incidence rates of HCC were 1.39 and 2.52 cases per 100 person-year in SGLT2i and non-SGLT2i groups, respectively. SGLT2i use was associated with a significantly lower risk of incident HCC (HR 0.54, 95%CI: 0.33-0.88, p =0.013). The association remained similar regardless of sex, age, glycemic control, diabetes duration, presence of cirrhosis and hepatic steatosis, timing of anti-HBV therapy, and background antidiabetic agents including dipeptidyl peptidase-4 inhibitors, insulin, or glitazones (all p interaction>0.05). CONCLUSIONS: Among patients with co-existing T2D and CHB, SGLT2i use was associated with a lower risk of incident HCC.


Assuntos
Carcinoma Hepatocelular , Diabetes Mellitus Tipo 2 , Hepatite B Crônica , Neoplasias Hepáticas , Inibidores do Transportador 2 de Sódio-Glicose , Humanos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/epidemiologia , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/prevenção & controle , Estudos de Coortes , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/prevenção & controle , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Hong Kong/epidemiologia , Hepatite B Crônica/complicações , Hepatite B Crônica/tratamento farmacológico , Estudos Retrospectivos
16.
Hepatology ; 77(1): 213-229, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-35363898

RESUMO

BACKGROUND AND AIMS: Metabolism in the liver is dysregulated in obesity, contributing to various health problems including steatosis and insulin resistance. While the pathogenesis of lipid accumulation has been extensively studied, the protective mechanism against lipid challenge in the liver remains unclear. Here, we report that Src homology 3 domain binding kinase 1 (SBK1) is a regulator of hepatic lipid metabolism and systemic insulin sensitivity in response to obesity. APPROACH AND RESULTS: Enhanced Sbk1 expression was found in the liver of high-fat diet (HFD)-induced obese mice and fatty acid (FA)-challenged hepatocytes. SBK1 knockdown in mouse liver cells augmented FA uptake and lipid accumulation. Similarly, liver-specific SBK1 knockout ( Lsko ) mice displayed more severe hepatosteatosis and higher expression of genes in FA uptake and lipogenesis than the Flox/Flox ( Fl/Fl ) control mice when fed the HFD. The HFD-fed Lsko mice also showed symptoms of hyperglycemia, poor systemic glucose tolerance, and lower insulin sensitivity than the Fl/Fl mice. On the other hand, hepatic Sbk1 overexpression alleviated the high-fructose diet-induced hepatosteatosis, hyperlipidemia, and hyperglycemia in mice. White adipose tissue browning was also observed in hepatic SBK1 -overexpressed mice. Moreover, we found that SBK1 was a positive regulator of FGF21 in the liver during energy surplus conditions. Mechanistically, SBK1 phosphorylates the orphan nuclear receptor 4A1 (Nur77) on serine 344 to promote hepatic FGF21 expression and inhibit the transcription of genes involved in lipid anabolism. CONCLUSIONS: Collectively, our data suggest that SBK1 is a regulator of the metabolic adaption against obesity through the Nur77-FGF21 pathway.


Assuntos
Fígado Gorduroso , Resistência à Insulina , Proteínas Quinases , Animais , Camundongos , Dieta Hiperlipídica/efeitos adversos , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Hiperglicemia/complicações , Hiperglicemia/metabolismo , Hiperglicemia/patologia , Lipídeos , Fígado/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/complicações , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares
17.
Blood ; 140(11): 1278-1290, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35639959

RESUMO

Peripheral T-cell lymphomas (PTCLs) are heterogenous T-cell neoplasms often associated with epigenetic dysregulation. We investigated de novo DNA methyltransferase 3A (DNMT3A) mutations in common PTCL entities, including angioimmunoblastic T-cell lymphoma and novel molecular subtypes identified within PTCL-not otherwise specified (PTCL-NOS) designated as PTCL-GATA3 and PTCL-TBX21. DNMT3A-mutated PTCL-TBX21 cases showed inferior overall survival (OS), with DNMT3A-mutated residues skewed toward the methyltransferase domain and dimerization motif (S881-R887). Transcriptional profiling demonstrated significant enrichment of activated CD8+ T-cell cytotoxic gene signatures in the DNMT3A-mutant PTCL-TBX21 cases, which was further validated using immunohistochemistry. Genomewide methylation analysis of DNMT3A-mutant vs wild-type (WT) PTCL-TBX21 cases demonstrated hypomethylation in target genes regulating interferon-γ (IFN-γ), T-cell receptor signaling, and EOMES (eomesodermin), a master transcriptional regulator of cytotoxic effector cells. Similar findings were observed in a murine model of PTCL with Dnmt3a loss (in vivo) and further validated in vitro by ectopic expression of DNMT3A mutants (DNMT3A-R882, -Q886, and -V716, vs WT) in CD8+ T-cell line, resulting in T-cell activation and EOMES upregulation. Furthermore, stable, ectopic expression of the DNMT3A mutants in primary CD3+ T-cell cultures resulted in the preferential outgrowth of CD8+ T cells with DNMT3AR882H mutation. Single-cell RNA sequencing(RNA-seq) analysis of CD3+ T cells revealed differential CD8+ T-cell subset polarization, mirroring findings in DNMT3A-mutated PTCL-TBX21 and validating the cytotoxic and T-cell memory transcriptional programs associated with the DNMT3AR882H mutation. Our findings indicate that DNMT3A mutations define a cytotoxic subset in PTCL-TBX21 with prognostic significance and thus may further refine pathological heterogeneity in PTCL-NOS and suggest alternative treatment strategies for this subset.


Assuntos
Interferon gama , Linfoma de Células T Periférico , Animais , Interferon gama/genética , Linfoma de Células T Periférico/patologia , Metiltransferases/genética , Camundongos , Mutação , Prognóstico , Receptores de Antígenos de Linfócitos T/genética
18.
Blood ; 140(21): 2193-2227, 2022 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-36001803

RESUMO

With the introduction of large-scale molecular profiling methods and high-throughput sequencing technologies, the genomic features of most lymphoid neoplasms have been characterized at an unprecedented scale. Although the principles for the classification and diagnosis of these disorders, founded on a multidimensional definition of disease entities, have been consolidated over the past 25 years, novel genomic data have markedly enhanced our understanding of lymphomagenesis and enriched the description of disease entities at the molecular level. Yet, the current diagnosis of lymphoid tumors is largely based on morphological assessment and immunophenotyping, with only few entities being defined by genomic criteria. This paper, which accompanies the International Consensus Classification of mature lymphoid neoplasms, will address how established assays and newly developed technologies for molecular testing already complement clinical diagnoses and provide a novel lens on disease classification. More specifically, their contributions to diagnosis refinement, risk stratification, and therapy prediction will be considered for the main categories of lymphoid neoplasms. The potential of whole-genome sequencing, circulating tumor DNA analyses, single-cell analyses, and epigenetic profiling will be discussed because these will likely become important future tools for implementing precision medicine approaches in clinical decision making for patients with lymphoid malignancies.


Assuntos
Linfoma , Neoplasias , Humanos , Linfoma/diagnóstico , Linfoma/genética , Linfoma/terapia , Genômica/métodos , Medicina de Precisão , Sequenciamento de Nucleotídeos em Larga Escala , Tomada de Decisão Clínica
19.
Blood ; 140(11): 1229-1253, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35653592

RESUMO

Since the publication of the Revised European-American Classification of Lymphoid Neoplasms in 1994, subsequent updates of the classification of lymphoid neoplasms have been generated through iterative international efforts to achieve broad consensus among hematopathologists, geneticists, molecular scientists, and clinicians. Significant progress has recently been made in the characterization of malignancies of the immune system, with many new insights provided by genomic studies. They have led to this proposal. We have followed the same process that was successfully used for the third and fourth editions of the World Health Organization Classification of Hematologic Neoplasms. The definition, recommended studies, and criteria for the diagnosis of many entities have been extensively refined. Some categories considered provisional have now been upgraded to definite entities. Terminology for some diseases has been revised to adapt nomenclature to the current knowledge of their biology, but these modifications have been restricted to well-justified situations. Major findings from recent genomic studies have impacted the conceptual framework and diagnostic criteria for many disease entities. These changes will have an impact on optimal clinical management. The conclusions of this work are summarized in this report as the proposed International Consensus Classification of mature lymphoid, histiocytic, and dendritic cell tumors.


Assuntos
Neoplasias Hematológicas , Linfoma , Comitês Consultivos , Consenso , Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/genética , Humanos , Linfoma/patologia , Organização Mundial da Saúde
20.
Br J Surg ; 111(5)2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38747328

RESUMO

BACKGROUND: Team diversity is recognized not only as an equity issue but also a catalyst for improved performance through diversity in knowledge and practices. However, team diversity data in healthcare are limited and it is not known whether it may affect outcomes in surgery. This study examined the association between anaesthesia-surgery team sex diversity and postoperative outcomes. METHODS: This was a population-based retrospective cohort study of adults undergoing major inpatient procedures between 2009 and 2019. The exposure was the hospital percentage of female anaesthetists and surgeons in the year of surgery. The outcome was 90-day major morbidity. Restricted cubic splines were used to identify a clinically meaningful dichotomization of team sex diversity, with over 35% female anaesthetists and surgeons representing higher diversity. The association with outcomes was examined using multivariable logistic regression. RESULTS: Of 709 899 index operations performed at 88 hospitals, 90-day major morbidity occurred in 14.4%. The median proportion of female anaesthetists and surgeons was 28 (interquartile range 25-31)% per hospital per year. Care in hospitals with higher sex diversity (over 35% female) was associated with reduced odds of 90-day major morbidity (OR 0.97, 95% c.i. 0.95 to 0.99; P = 0.02) after adjustment. The magnitude of this association was greater for patients treated by female anaesthetists (OR 0.92, 0.88 to 0.97; P = 0.002) and female surgeons (OR 0.83, 0.76 to 0.90; P < 0.001). CONCLUSION: Care in hospitals with greater anaesthesia-surgery team sex diversity was associated with better postoperative outcomes. Care in a hospital reaching a critical mass with over 35% female anaesthetists and surgeons, representing higher team sex-diversity, was associated with a 3% lower odds of 90-day major morbidity.


Assuntos
Equipe de Assistência ao Paciente , Complicações Pós-Operatórias , Humanos , Feminino , Estudos Retrospectivos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Idoso , Adulto , Cirurgiões/estatística & dados numéricos , Procedimentos Cirúrgicos Operatórios/estatística & dados numéricos , Médicas/estatística & dados numéricos
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