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1.
Cell ; 173(2): 430-442.e17, 2018 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-29606353

RESUMO

Fetal hemoglobin (HbF, α2γ2) level is genetically controlled and modifies severity of adult hemoglobin (HbA, α2ß2) disorders, sickle cell disease, and ß-thalassemia. Common genetic variation affects expression of BCL11A, a regulator of HbF silencing. To uncover how BCL11A supports the developmental switch from γ- to ß- globin, we use a functional assay and protein binding microarray to establish a requirement for a zinc-finger cluster in BCL11A in repression and identify a preferred DNA recognition sequence. This motif appears in embryonic and fetal-expressed globin promoters and is duplicated in γ-globin promoters. The more distal of the duplicated motifs is mutated in individuals with hereditary persistence of HbF. Using the CUT&RUN approach to map protein binding sites in erythroid cells, we demonstrate BCL11A occupancy preferentially at the distal motif, which can be disrupted by editing the promoter. Our findings reveal that direct γ-globin gene promoter repression by BCL11A underlies hemoglobin switching.


Assuntos
Proteínas de Transporte/metabolismo , Hemoglobina Fetal/genética , Proteínas Nucleares/metabolismo , Sequência de Bases , Sítios de Ligação , Proteínas de Transporte/genética , Linhagem Celular , Cromatina/metabolismo , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Células Eritroides/citologia , Células Eritroides/metabolismo , Edição de Genes , Humanos , Proteínas Nucleares/genética , Regiões Promotoras Genéticas , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Repressoras , Dedos de Zinco/genética , Globinas beta/genética , Talassemia beta/genética , Talassemia beta/patologia , gama-Globinas/genética
2.
Nano Lett ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38874568

RESUMO

Blood-contacting medical devices (BCDs) require antithrombotic, antibacterial, and low-friction surfaces. Incorporating a nanostructured surface with the functional hydrogel onto BCD surfaces can enhance the performances; however, their fabrication remains challenging. Here, we introduce a straightforward method to fabricate a multifunctional hydrogel-based nanostructure on BCD surfaces using O-carboxymethyl chitosan-based short nanofibers (CMC-SNFs). CMC-SNFs, fabricated via electrospinning and cutting processes, are easily sprayed and entangled onto the BCD surface. The deposited CMC-SNFs form a robust nanoweb layer via fusion at the contact area of the nanofiber interfaces. The superhydrophilic CMS-SNF nanoweb surface creates a water-bound layer that effectively prevents the nonspecific adhesion of bacteria and blood cells, thereby enhancing both antimicrobial and antithrombotic performances. Furthermore, the CMC-SNF nanoweb exhibits excellent lubricity and durability on the bovine aorta. The demonstration results of the CMC-SNF coating on catheters and sheaths provide evidence of its capability to apply multifunctional surfaces simply for diverse BCDs.

3.
J Biol Chem ; 299(7): 104901, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37302550

RESUMO

Collagen superfamily of proteins is a major component of the extracellular matrix. Defects in collagens underlie the cause of nearly 40 human genetic diseases in millions of people worldwide. Pathogenesis typically involves genetic alterations of the triple helix, a hallmark structural feature that bestows exceptional mechanical resistance to tensile forces and a capacity to bind a plethora of macromolecules. Yet, there is a paramount knowledge gap in understanding the functionality of distinct sites along the triple helix. Here, we present a recombinant technique to produce triple helical fragments for functional studies. The experimental strategy utilizes the unique capacity of the NC2 heterotrimerization domain of collagen IX to drive three α-chain selection and registering the triple helix stagger. For proof of principle, we produced and characterized long triple helical fragments of collagen IV that were expressed in a mammalian system. The heterotrimeric fragments encompassed the CB3 trimeric peptide of collagen IV, which harbors the binding motifs for α1ß1 and α2ß1 integrins. Fragments were characterized and shown to have a stable triple helix, post-translational modifications, and high affinity and specific binding of integrins. The NC2 technique is a universal tool for the high-yield production of heterotrimeric fragments of collagens. Fragments are suitable for mapping functional sites, determining coding sequences of binding sites, elucidating pathogenicity and pathogenic mechanisms of genetic mutations, and production of fragments for protein replacement therapy.


Assuntos
Colágeno Tipo IV , Integrinas , Multimerização Proteica , Animais , Humanos , Sítios de Ligação , Colágeno Tipo IV/química , Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Integrinas/química , Integrinas/metabolismo , Ligação Proteica , Estrutura Secundária de Proteína , Mutação , Domínios Proteicos
4.
Neurobiol Dis ; 190: 106369, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38049012

RESUMO

Sleep-wake disturbances are common in neurodegenerative diseases and may occur years before the clinical diagnosis, potentially either representing an early stage of the disease itself or acting as a pathophysiological driver. Therefore, discovering biomarkers that identify individuals with sleep-wake disturbances who are at risk of developing neurodegenerative diseases will allow early diagnosis and intervention. Given the association between sleep and neurodegeneration, the most frequently analyzed fluid biomarkers in people with sleep-wake disturbances to date include those directly associated with neurodegeneration itself, such as neurofilament light chain, phosphorylated tau, amyloid-beta and alpha-synuclein. Abnormalities in these biomarkers in patients with sleep-wake disturbances are considered as evidence of an underlying neurodegenerative process. Levels of hormonal sleep-related biomarkers such as melatonin, cortisol and orexin are often abnormal in patients with clinical neurodegenerative diseases, but their relationships with the more standard neurodegenerative biomarkers remain unclear. Similarly, it is unclear whether other chronobiological/circadian biomarkers, such as disrupted clock gene expression, are causal factors or a consequence of neurodegeneration. Current data would suggest that a combination of fluid biomarkers may identify sleep-wake disturbances that are most predictive for the risk of developing neurodegenerative disease with more optimal sensitivity and specificity.


Assuntos
Doenças Neurodegenerativas , Transtornos do Sono-Vigília , Humanos , Sono/fisiologia , Peptídeos beta-Amiloides/metabolismo , Transtornos do Sono-Vigília/diagnóstico , Transtornos do Sono-Vigília/etiologia , Transtornos do Sono-Vigília/metabolismo , Biomarcadores
5.
Expert Rev Proteomics ; : 1-10, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38697802

RESUMO

INTRODUCTION: The proactive identification of diseases through screening tests has long been endorsed as a means to preempt symptomatic onset. However, such screening endeavors are fraught with complications, such as diagnostic inaccuracies, procedural risks, and patient unease during examinations. These challenges are amplified when screenings for multiple diseases are administered concurrently. Selected Reaction Monitoring (SRM) offers a unique advantage, allowing for the high-throughput quantification of hundreds of analytes with minimal interferences. AREAS COVERED: Our research posits that SRM-based assays, traditionally tailored for single-disease biomarker profiling, can be repurposed for multi-disease screening. This innovative approach has the potential to substantially alleviate time, labor, and cost demands on healthcare systems and patients alike. Nonetheless, there are formidable methodological hurdles to overcome. These include difficulties in detecting low-abundance proteins and the risk of model overfitting due to the multiple functionalities of single proteins across different disease spectrums - issues especially pertinent in blood-based assays where detection sensitivity is constrained. As we move forward, technological strides in sample preparation, online extraction, throughput, and automation are expected to ameliorate these limitations. EXPERT OPINION: The maturation of mass spectrometry's integration into clinical laboratories appears imminent, positioning it as an invaluable asset for delivering highly sensitive, reproducible, and precise diagnostic results.

6.
AJR Am J Roentgenol ; 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38598354

RESUMO

Large language models (LLMs) hold immense potential to revolutionize radiology. However, their integration into practice requires careful consideration. Artificial intelligence (AI) chatbots and general-purpose LLMs have potential pitfalls related to privacy, transparency, and accuracy, limiting their current clinical readiness. Thus, LLM-based tools must be optimized for radiology practice to overcome these limitations. While research and validation for radiology applications remain in their infancy, commercial products incorporating LLMs are becoming available alongside promises of transforming practice. To help radiologists navigate this landscape, this AJR Expert Panel Narrative Review provides a multidimensional perspective on LLMs, encompassing considerations from bench (development and optimization) to bedside (use in practice). At present, LLMs are not autonomous entities that can replace expert decision-making, and radiologists remain responsible for the content of their reports. Patient-facing tools, particularly medical AI chatbots, require additional guardrails to ensure safety and prevent misuse. Still, if responsibly implemented, LLMs are well-positioned to transform efficiency and quality in radiology. Radiologists must be well-informed and proactively involved in guiding the implementation of LLMs in practice to mitigate risks and maximize benefits to patient care.

7.
Fish Shellfish Immunol ; 151: 109681, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38871142

RESUMO

The EGF-containing fibulin-like extracellular matrix protein 2 (EFEMP2) is involved in connective tissue development, elastic fiber formation, and tumor growth. In this study, we characterized the cDNA of EFEMP2 (PoEFEMP2), a member of the fibulin family of ECM proteins, in the olive flounder Paralichthys olivaceus. The coding region of PoEFEMP2 encodes a protein that contains six calcium-binding EGF-like (EGF-CA) domains and four complement Clr-like EGF-like (cEGF) domains. PoEFEMP2 shows 67.51-96.77 % similarities to orthologs in a variety of fish species. PoEFEMP2 mRNA was detected in all tissues examined; the highest levels of PoEFEMP2 mRNA expression were observed in the heart, testis, ovary and muscle. The PoEFEMP2 mRNA level increases during early development. In addition, the PoEFEMP2 mRNA level increased at 3 h post-infection (hpi) and decreased from 6 to 48 hpi in flounder Hirame natural embryo (HINAE) cells infected with viral hemorrhagic septicemia virus (VHSV). Disruption of PoEFEMP2 using the clustered regularly interspaced short palindromic repeats/CRISPR-associated-9 (CRISPR/Cas9) system resulted in a significant upregulation of VHSV G mRNA levels and immune-related genes expression in knockout cells. These findings implicate PoEFEMP2 in antiviral responses in P. olivaceus.

8.
Cell ; 139(7): 1303-14, 2009 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-20064376

RESUMO

Trimethylation on histone H3 lysine 27 (H3K27me3) by Polycomb repressive complex 2 (PRC2) regulates the balance between self-renewal and differentiation of embryonic stem cells (ESCs). The mechanisms controlling the activity and recruitment of PRC2 are largely unknown. Here we demonstrate that the founding member of the Jumonji family, JMJ (JUMONJI or JARID2), is associated with PRC2, colocalizes with PRC2 and H3K27me3 on chromatin, and modulates PRC2 function. In vitro JMJ inhibits PRC2 methyltransferase activity, consistent with increased H3K27me3 marks at PRC2 targets in Jmj(-/-) ESCs. Paradoxically, JMJ is required for efficient binding of PRC2, indicating that the interplay of PRC2 and JMJ fine-tunes deposition of the H3K27me3 mark. During differentiation, activation of genes marked by H3K27me3 and lineage commitments are delayed in Jmj(-/-) ESCs. Our results demonstrate that dynamic regulation of Polycomb complex activity orchestrated by JMJ balances self-renewal and differentiation, highlighting the involvement of chromatin dynamics in cell-fate transitions.


Assuntos
Células-Tronco Embrionárias/citologia , Proteínas do Tecido Nervoso/metabolismo , Proteínas Repressoras/metabolismo , Animais , Diferenciação Celular , Montagem e Desmontagem da Cromatina , Células HeLa , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Humanos , Camundongos , Complexo Repressor Polycomb 2 , Proteínas do Grupo Polycomb
9.
Proc Natl Acad Sci U S A ; 118(10)2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33649207

RESUMO

Tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase 1 (IDO1) also has an immunological function to suppress T cell activation in inflammatory circumstances, including graft-versus-host disease (GVHD), a fatal complication after allogeneic bone marrow transplantation (allo-BMT). Although the mononuclear cell expression of IDO1 has been associated with improved outcomes in GVHD, the underlying mechanisms remain unclear. Herein, we used IDO-deficient (Ido1-/-) BMT to understand why myeloid IDO limits the severity of GVHD. Hosts with Ido1-/- BM exhibited increased lethality, with enhanced proinflammatory and reduced regulatory T cell responses compared with wild type (WT) allo-BMT controls. Despite the comparable expression of the myeloid-derived suppressor cell (MDSC) mediators, arginase-1, inducible nitric oxide synthase, and interleukin 10, Ido1-/- Gr-1+CD11b+ cells from allo-BMT or in vitro BM culture showed compromised immune-suppressive functions and were skewed toward the Ly6ClowLy6Ghi subset, compared with the WT counterparts. Importantly, Ido1-/-Gr-1+CD11b+ cells exhibited elevated levels of reactive oxygen species (ROS) and neutrophil numbers. These characteristics were rescued by human IDO1 with intact heme-binding and catalytic activities and were recapitulated by the treatment of WT cells with the IDO1 inhibitor L1-methyl tryptophan. ROS scavenging by N-acetylcysteine reverted the Ido1-/-Gr-1+CD11b+ composition and function to an MDSC state, as well as improved the survival of GVHD hosts with Ido1-/- BM. In summary, myeloid-derived IDO1 enhances GVHD survival by regulating ROS levels and limiting the ability of Gr-1+CD11b+ MDSCs to differentiate into proinflammatory neutrophils. Our findings provide a mechanistic insight into the immune-regulatory roles of the metabolic enzyme IDO1.


Assuntos
Transplante de Medula Óssea , Doença Enxerto-Hospedeiro/imunologia , Indolamina-Pirrol 2,3,-Dioxigenase/imunologia , Células Supressoras Mieloides/imunologia , Espécies Reativas de Oxigênio/imunologia , Aloenxertos , Animais , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Camundongos , Camundongos Knockout
10.
J Biol Chem ; 298(8): 102260, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35841928

RESUMO

The propagation and accumulation of pathological α-synuclein protein is thought to underlie the clinical symptoms of the neurodegenerative movement disorder Parkinson's disease (PD). Consequently, there is significant interest in identifying the mechanisms that contribute to α-synuclein pathology, as these may inform therapeutic targets for the treatment of PD. One protein that appears to contribute to α-synuclein pathology is the innate immune pathogen recognition receptor, toll-like receptor 2 (TLR2). TLR2 is expressed on neurons, and its activation results in the accumulation of α-synuclein protein; however, the precise mechanism by which TLR2 contributes to α-synuclein pathology is unclear. Herein we demonstrate using human cell models that neuronal TLR2 activation acutely impairs the autophagy lysosomal pathway and markedly potentiates α-synuclein pathology seeded with α-synuclein preformed fibrils. Moreover, α-synuclein pathology could be ameliorated with a novel small molecule TLR2 inhibitor, including in induced pluripotent stem cell-derived neurons from a patient with PD. These results provide further insight into how TLR2 activation may promote α-synuclein pathology in PD and support that TLR2 may be a potential therapeutic target for the treatment of PD.


Assuntos
Doenças Neurodegenerativas , Doença de Parkinson , Humanos , Doenças Neurodegenerativas/metabolismo , Neurônios/metabolismo , Doença de Parkinson/metabolismo , Receptor 2 Toll-Like/metabolismo , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo
11.
Mol Cancer ; 22(1): 164, 2023 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-37803338

RESUMO

To address the shortcomings of current hepatocellular carcinoma (HCC) surveillance tests, we set out to find HCC-specific methylation markers and develop a highly sensitive polymerase chain reaction (PCR)-based method to detect them in circulating cell-free DNA (cfDNA). The analysis of large methylome data revealed that Ring Finger Protein 135 (RNF135) and Lactate Dehydrogenase B (LDHB) are universally applicable HCC methylation markers with no discernible methylation level detected in any other tissue types. These markers were used to develop Methylation Sensitive High-Resolution Analysis (MS-HRM), and their diagnostic accuracy was tested using cfDNA from healthy, at-risk, and HCC patients. The combined MS-HRM RNF135 and LDHB analysis detected 57% of HCC, outperforming the alpha-fetoprotein (AFP) test's sensitivity of 45% at comparable specificity. Furthermore, when used with the AFP test, the methylation assay can detect 70% of HCC. Our findings suggest that the cfDNA methylation assay could be used for HCC liquid biopsy.


Assuntos
Carcinoma Hepatocelular , Ácidos Nucleicos Livres , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , alfa-Fetoproteínas/genética , alfa-Fetoproteínas/análise , alfa-Fetoproteínas/metabolismo , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Metilação de DNA , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Ácidos Nucleicos Livres/genética , Ubiquitina-Proteína Ligases/metabolismo
12.
Fish Shellfish Immunol ; 142: 109077, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37726081

RESUMO

We explored the biotechnological applicability of a previously established olive flounder (Paralichthys olivaceus) embryonic cell line (FGBC8). FGBC8 was transfected with pEGFP-c1 and pluripotency-related genes, then infected with viral hemorrhagic septicemia virus (VHSV), and the expression of immune-related genes was observed through quantitative real-time polymerase chain reaction. Transfected cells showed strong green fluorescence 48 h after transfection, and pluripotency-related genes were successfully transfected. In addition, FGBC8 cells were highly susceptible to VHSV and the expression of immune-related genes was induced during infection. Our results demonstrate that FGBC8 cells are valuable research tools for assessing host-pathogen interactions and biotechnological applications.


Assuntos
Doenças dos Peixes , Linguado , Septicemia Hemorrágica Viral , Novirhabdovirus , Animais , Linguado/genética , Análise Citogenética , Linhagem Celular , Novirhabdovirus/genética
13.
Org Biomol Chem ; 21(18): 3881-3895, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37097478

RESUMO

Herein we describe the divergent synthesis of two types of indolizines via construction of the pyrrole moiety from pyridine-2-acetonitriles, arylglyoxals, and TMSCN. While one-pot three-component coupling provided 2-aryl-3-aminoindolizines via an unusual fragmentation process, a sequential two-step assembly protocol with these starting materials allowed efficient access to a wide range of new 2-acyl-3-aminoindolizines through an aldol condensation-Michael addition-cycloisomerization process. The subsequent manipulation of 2-acyl-3-aminoindolizines enabled direct access to novel polycyclic N-fused heteroaromatic skeletons.

14.
Brain ; 145(10): 3472-3487, 2022 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-35551349

RESUMO

Many genetic risk factors for Parkinson's disease have lipid-related functions and lipid-modulating drugs such as statins may be protective against Parkinson's disease. Moreover, the hallmark Parkinson's disease pathological protein, α-synuclein, has lipid membrane function and pathways dysregulated in Parkinson's disease such as the endosome-lysosome system and synaptic signalling rely heavily on lipid dynamics. Despite the potential role for lipids in Parkinson's disease, most research to date has been protein-centric, with large-scale, untargeted serum and CSF lipidomic comparisons between genetic and idiopathic Parkinson's disease and neurotypical controls limited. In particular, the extent to which lipid dysregulation occurs in mutation carriers of one of the most common Parkinson's disease risk genes, LRRK2, is unclear. Further, the functional lipid pathways potentially dysregulated in idiopathic and LRRK2 mutation Parkinson's disease are underexplored. To better determine the extent of lipid dysregulation in Parkinson's disease, untargeted high-performance liquid chromatography-tandem mass spectrometry was performed on serum (n = 221) and CSF (n = 88) obtained from a multi-ethnic population from the Michael J. Fox Foundation LRRK2 Clinical Cohort Consortium. The cohort consisted of controls, asymptomatic LRRK2 G2019S carriers, LRRK2 G2019S carriers with Parkinson's disease and Parkinson's disease patients without a LRRK2 mutation. Age and sex were adjusted for in analyses where appropriate. Approximately 1000 serum lipid species per participant were analysed. The main serum lipids that distinguished both Parkinson's disease patients and LRRK2 mutation carriers from controls included species of ceramide, triacylglycerol, sphingomyelin, acylcarnitine, phosphatidylcholine and lysophosphatidylethanolamine. Significant alterations in sphingolipids and glycerolipids were also reflected in Parkinson's disease and LRRK2 mutation carrier CSF, although no correlations were observed between lipids identified in both serum and CSF. Pathway analysis of altered lipid species indicated that sphingolipid metabolism, insulin signalling and mitochondrial function were the major metabolic pathways dysregulated in Parkinson's disease. Importantly, these pathways were also found to be dysregulated in serum samples from a second Parkinson's disease cohort (n = 315). Results from this study demonstrate that dysregulated lipids in Parkinson's disease generally, and in LRRK2 mutation carriers, are from functionally and metabolically related pathways. These findings provide new insight into the extent of lipid dysfunction in Parkinson's disease and therapeutics manipulating these pathways may be beneficial for Parkinson's disease patients. Moreover, serum lipid profiles may be novel biomarkers for both genetic and idiopathic Parkinson's disease.


Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases , Insulinas , Doença de Parkinson , Humanos , Doença de Parkinson/metabolismo , alfa-Sinucleína , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Esfingomielinas , Biomarcadores , Ceramidas , Fosfatidilcolinas , Triglicerídeos
15.
Brain ; 145(5): 1598-1609, 2022 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-35202463

RESUMO

Frontotemporal dementia refers to a group of neurodegenerative disorders characterized by behaviour and language alterations and focal brain atrophy. Amyotrophic lateral sclerosis is a rapidly progressing neurodegenerative disease characterized by loss of motor neurons resulting in muscle wasting and paralysis. Frontotemporal dementia and amyotrophic lateral sclerosis are considered to exist on a disease spectrum given substantial overlap of genetic and molecular signatures. The predominant genetic abnormality in both frontotemporal dementia and amyotrophic lateral sclerosis is an expanded hexanucleotide repeat sequence in the C9orf72 gene. In terms of brain pathology, abnormal aggregates of TAR-DNA-binding protein-43 are predominantly present in frontotemporal dementia and amyotrophic lateral sclerosis patients. Currently, sensitive and specific diagnostic and disease surveillance biomarkers are lacking for both diseases. This has impeded the capacity to monitor disease progression during life and the development of targeted drug therapies for the two diseases. The purpose of this review is to examine the status of current biofluid biomarker discovery and development in frontotemporal dementia and amyotrophic lateral sclerosis. The major pathogenic proteins implicated in different frontotemporal dementia and amyotrophic lateral sclerosis molecular subtypes and proteins associated with neurodegeneration and the immune system will be discussed. Furthermore, the use of mass spectrometry-based proteomics as an emerging tool to identify new biomarkers in frontotemporal dementia and amyotrophic lateral sclerosis will be summarized.


Assuntos
Esclerose Lateral Amiotrófica , Demência Frontotemporal , Doenças Neurodegenerativas , Doença de Pick , Esclerose Lateral Amiotrófica/diagnóstico , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Proteína C9orf72/genética , Expansão das Repetições de DNA , Demência Frontotemporal/genética , Demência Frontotemporal/patologia , Humanos , Doenças Neurodegenerativas/patologia
16.
Mol Cell ; 57(2): 304-316, 2015 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-25578878

RESUMO

Polycomb repressive complex 2 (PRC2) plays crucial roles in transcriptional regulation and stem cell development. However, the context-specific functions associated with alternative subunits remain largely unexplored. Here we show that the related enzymatic subunits EZH1 and EZH2 undergo an expression switch during blood cell development. An erythroid-specific enhancer mediates transcriptional activation of EZH1, and a switch from GATA2 to GATA1 controls the developmental EZH1/2 switch by differential association with EZH1 enhancers. We further examine the in vivo stoichiometry of the PRC2 complexes by quantitative proteomics and reveal the existence of an EZH1-SUZ12 subcomplex lacking EED. EZH1 together with SUZ12 form a non-canonical PRC2 complex, occupy active chromatin, and positively regulate gene expression. Loss of EZH2 expression leads to repositioning of EZH1 to EZH2 targets. Thus, the lineage- and developmental stage-specific regulation of PRC2 subunit composition leads to a switch from canonical silencing to non-canonical functions during blood stem cell specification.


Assuntos
Fatores de Transcrição GATA/fisiologia , Complexo Repressor Polycomb 2/metabolismo , Sequência de Bases , Carcinogênese , Proteína Potenciadora do Homólogo 2 de Zeste , Epigênese Genética , Células Eritroides/metabolismo , Hematopoese , Células-Tronco Hematopoéticas , Histonas/metabolismo , Humanos , Células K562 , Metilação , Regiões Promotoras Genéticas , Processamento de Proteína Pós-Traducional , Subunidades Proteicas
17.
Cell Mol Life Sci ; 79(3): 155, 2022 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-35218410

RESUMO

Cellular senescence is closely related to tissue aging including bone. Bone homeostasis is maintained by the tight balance between bone-forming osteoblasts and bone-resorbing osteoclasts, but it undergoes deregulation with age, causing age-associated osteoporosis, a main cause of which is osteoblast dysfunction. Oxidative stress caused by the accumulation of reactive oxygen species (ROS) in bone tissues with aging can accelerate osteoblast senescence and dysfunction. However, the regulatory mechanism that controls the ROS-induced senescence of osteoblasts is poorly understood. Here, we identified Peptidyl arginine deiminase 2 (PADI2), a post-translational modifying enzyme, as a regulator of ROS-accelerated senescence of osteoblasts via RNA-sequencing and further functional validations. PADI2 downregulation by treatment with H2O2 or its siRNA promoted cellular senescence and suppressed osteoblast differentiation. CCL2, 5, and 7 known as the elements of the senescence-associated secretory phenotype (SASP) which is a secretome including proinflammatory cytokines and chemokines emitted by senescent cells and a representative feature of senescence, were upregulated by H2O2 treatment or Padi2 knockdown. Furthermore, blocking these SASP factors with neutralizing antibodies or siRNAs alleviated the senescence and dysfunction of osteoblasts induced by H2O2 treatment or Padi2 knockdown. The elevated production of these SASP factors was mediated by the activation of NFκB signaling pathway. The inhibition of NFκB using the pharmacological inhibitor or siRNA effectively relieved H2O2 treatment- or Padi2 knockdown-induced senescence and osteoblast dysfunction. Together, our study for the first time uncover the role of PADI2 in ROS-accelerated cellular senescence of osteoblasts and provide new mechanistic and therapeutic insights into excessive ROS-promoted cellular senescence and aging-related bone diseases.


Assuntos
Senescência Celular/efeitos dos fármacos , Quimiocinas CC/metabolismo , Peróxido de Hidrogênio/farmacologia , NF-kappa B/metabolismo , Proteína-Arginina Desiminase do Tipo 2/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Quimiocina CCL2/antagonistas & inibidores , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Quimiocina CCL5/antagonistas & inibidores , Quimiocina CCL5/genética , Quimiocina CCL5/metabolismo , Quimiocina CCL7/antagonistas & inibidores , Quimiocina CCL7/genética , Quimiocina CCL7/metabolismo , Quimiocinas CC/antagonistas & inibidores , Quimiocinas CC/genética , Dano ao DNA/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Camundongos , Osteoblastos/citologia , Osteoblastos/metabolismo , Proteína-Arginina Desiminase do Tipo 2/antagonistas & inibidores , Proteína-Arginina Desiminase do Tipo 2/genética , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
18.
J Invertebr Pathol ; 198: 107926, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37087092

RESUMO

Ticks are carriers of viruses that can cause disease in humans and animals. The longhorned ticks (Haemaphysalis longicornis; LHT), for example, mediates the severe fever with thrombocytopenia syndrome virus (SFTSV) in humans, and the population of ticks is growing due to increases in temperature caused by climate change. As ticks carry primarily RNA viruses, there is a need to study the possibility of detecting new viruses through tick virome analysis. In this study, viruses in LHTs collected in Korea were investigated and virus titers in ticks exposed to the entomopathogenic fungus Metarhizium anisopliae JEF-290 were analyzed. Total RNA was extracted from the collected ticks, and short reads were obtained from Illumina sequencing. A total of 50,024 contigs with coding capacity were obtained after de novo assembly of the reads in the metaSPAdes genome assembler. A series of BLAST-based analyses using the GenBank database was performed to screen viral contigs, and three putative virus species were identified from the tick meta-transcriptome, such as Alongshan virus (ALSV), Denso virus and Taggert virus. Measurements of virus-expression levels of infected and non-infected LHTs failed to detect substantial differences in expression levels. However, we suggest that LHT can spread not only SFTSV, but also various other disease-causing viruses over large areas of the world. From the phylogenetic analysis of ALSV glycoproteins, genetic differences in the ALSV could be due to host differences as well as regional differences. Viral metagenome analysis can be used as a tool to manage future outbreaks of disease caused by ticks by detecting unknown viruses.


Assuntos
Ixodidae , Metarhizium , Carrapatos , Humanos , Animais , Metarhizium/genética , Filogenia , Ixodidae/genética , Ixodidae/microbiologia , Genes Virais , Perfilação da Expressão Gênica
19.
Health Commun ; 38(4): 732-741, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-34474607

RESUMO

In the context of the COVID-19 pandemic, the authors conduct three online studies to examine effects of health messages that use descriptive norms to bring attention to pervasive social distancing violations and vaccine resistance. The studies provide empirical evidence that when social messages show examples of widespread noncompliant behaviors, they may unintentionally increase resistance to social distancing guidelines and vaccinations. Backfire effects are more pronounced when audiences highly identify with noncompliant actors or pay more attention to others' behaviors. We also show that injunctive norms should be included to alleviate backfire effects. The studies suggest that governments and authorities can more effectively encourage compliance with health guidelines by focusing on the majority of compliant individuals rather than broadcasting images of noncompliant individuals.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Distanciamento Físico , Pandemias/prevenção & controle , Vacinação
20.
Ecotoxicol Environ Saf ; 264: 115479, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37716066

RESUMO

Bisphenol A (BPA) is widely used in the production of plastics, food containers, and receipt ink globally. However, research has identified it as an endocrine disruptor, affecting the hormonal balance in living organisms. Bisphenol S (BPS), one of the alternative substances, was developed, but its effects on human health and the underlying mechanisms remain unclarified. Specifically, research on the effects of oral exposure to bisphenol on the lungs is lacking. We examined the potential differences in toxicity between these compounds in lung cells in vitro and in vivo. Our toxicity mechanism studies on MRC5 and A549 cells exposed to BPA or BPS revealed that BPA induced actin filament abnormalities and activated epithelial-mesenchymal transition (EMT). This finding suggests an increased potential for lung fibrosis and metastasis in lung cancer. However, given that BPS was not detected at the administered dose and under the specific experimental conditions, the probability of these occurrences is considered minimal. Additionally, animal experiments confirmed that oral exposure to BPA activates EMT in the lungs. Our study provides evidence that prolonged oral exposure to BPA can lead to EMT activation in lung tissue, similar to that observed in cell experiments, suggesting the potential to induce lung fibrosis. This research emphasizes the importance of regulating the use of BPA to mitigate its associated pulmonary toxicity. Furthermore, it is significant that within the parameters of our experimental conditions, BPS did not exhibit the toxicological pathways clearly evident in BPA.


Assuntos
Fibrose Pulmonar , Animais , Humanos , Fibrose Pulmonar/induzido quimicamente , Fenóis/toxicidade , Pulmão
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