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1.
BMC Biol ; 21(1): 293, 2023 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-38110916

RESUMO

BACKGROUND: Alzheimer's disease (AD) is the most common neurodegenerative disorder with clinical presentations of progressive cognitive and memory deterioration. The pathologic hallmarks of AD include tau neurofibrillary tangles and amyloid plaque depositions in the hippocampus and associated neocortex. The neuronal aggregated tau observed in AD cells suggests that the protein folding problem is a major cause of AD. J-domain-containing proteins (JDPs) are the largest family of cochaperones, which play a vital role in specifying and directing HSP70 chaperone functions. JDPs bind substrates and deliver them to HSP70. The association of JDP and HSP70 opens the substrate-binding domain of HSP70 to help the loading of the clients. However, in the initial HSP70 cycle, which JDP delivers tau to the HSP70 system in neuronal cells remains unclear. RESULTS: We screened the requirement of a diverse panel of JDPs for preventing tau aggregation in the human neuroblastoma cell line SH-SY5Y by a filter retardation method. Interestingly, knockdown of DNAJB6, one of the JDPs, displayed tau aggregation and overexpression of DNAJB6b, one of the isoforms generated from the DNAJB6 gene by alternative splicing, reduced tau aggregation. Further, the tau bimolecular fluorescence complementation assay confirmed the DNAJB6b-dependent tau clearance. The co-immunoprecipitation and the proximity ligation assay demonstrated the protein-protein interaction between tau and the chaperone-cochaperone complex. The J-domain of DNAJB6b was critical for preventing tau aggregation. Moreover, reduced DNAJB6 expression and increased tau aggregation were detected in an age-dependent manner in immunohistochemical analysis of the hippocampus tissues of a mouse model of tau pathology. CONCLUSIONS: In summary, downregulation of DNAJB6b increases the insoluble form of tau, while overexpression of DNAJB6b reduces tau aggregation. Moreover, DNAJB6b associates with tau. Therefore, this study reveals that DNAJB6b is a direct sensor for its client tau in the HSP70 folding system in neuronal cells, thus helping to prevent AD.


Assuntos
Doença de Alzheimer , Proteínas de Choque Térmico HSP40 , Chaperonas Moleculares , Proteínas do Tecido Nervoso , Neuroblastoma , Animais , Humanos , Camundongos , Processamento Alternativo , Doença de Alzheimer/genética , Proteínas de Choque Térmico HSP40/genética , Proteínas de Choque Térmico HSP40/química , Proteínas de Choque Térmico HSP40/metabolismo , Proteínas de Choque Térmico HSP70/genética , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Proteínas do Tecido Nervoso/genética , Dobramento de Proteína , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo
2.
Environ Res ; 224: 115426, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36781010

RESUMO

One of the major health issues facing people worldwide is liver fibrosis. Liver fibrosis may be brought on by long-term exposure to harmful substances, medicines, and microorganisms. The development of liver fibrosis in children was particularly worrying due to their longer life-span, which was possibly related to a great risk of developing long-term complications. Marine algae species have provided a biological variety in the research phase of novel approaches to the treatment of numerous ailments. Marine macroalgae have recently been the subject of research due to their rich bioactive chemical composition and potential for the production of various nutraceuticals. Macroalgae are potentially excellent sources of bioactive substances with particular and distinct biological activity when compared to their terrestrial equivalents. Macroalgae in diverse marine cases offer a few biologically active metabolites, comprising sterols, polyunsaturated fatty acids, carotenoids, oligosaccharides, polysaccharides, proteins, polyphenols, vitamins, and minerals. Accordingly, there is great interest in their high potential for supporting immunomodulatory, antimicrobial, antidiabetic, antitumoral, anti-inflammatory, antiangiogenic, and neuroprotective properties. Using an experimental model, the current research intends to collect data on the therapeutic value of macroalgae nanoparticles for fatty liver disease. The researchers' goal of predicting illnesses from the extensive medical datasets is quite difficult. The purpose of this research is to assess the protective effects of a seaweed, Padina pavonia (PP), on liver fibrosis caused by carbon tetrachloride (CCl4). This research presents two models of logistic regression (LR) and support vector machines (SVM) for predicting the likelihood of liver disease incidence. The performance of the model was evaluated using a dataset. PP macro-algae considerably reduce the high blood concentrations of aminotransferases, alkaline phosphatases, and lactate dehydrogenases, as well as causing a considerable (p < 0.05) decrease in serum bilirubin levels. In addition to improving kidney function (urea and creatinine), algal extracts enhance fat metabolism (triglycerides and cholesterol). With an accuracy rate of 70.2%, a sensitivity of 92.3%, a specificity of 74.7%, a type I error of 9.1%, and a type II error of 21.0%, the predictive model has demonstrated excellent performance. The model validated laboratory tests' ability to predict illness (age; direct bilirubin (DB), total proteins (TP), and albumin (ALB). These classifier methods are compared on the basis of their execution time and classification accuracy.


Assuntos
Alga Marinha , Criança , Humanos , Alga Marinha/química , Alga Marinha/metabolismo , Máquina de Vetores de Suporte , Modelos Logísticos , Cirrose Hepática , Bilirrubina/metabolismo
3.
Small ; 18(2): e2105076, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34799991

RESUMO

Effects of electronic and atomic structures of V-doped 2D layered SnS2 are studied using X-ray spectroscopy for the development of photocatalytic/photovoltaic applications. Extended X-ray absorption fine structure measurements at V K-edge reveal the presence of VO and VS bonds which form the intercalation of tetrahedral OVS sites in the van der Waals (vdW) gap of SnS2 layers. X-ray absorption near-edge structure (XANES) reveals not only valence state of V dopant in SnS2 is ≈4+ but also the charge transfer (CT) from V to ligands, supported by V Lα,ß resonant inelastic X-ray scattering. These results suggest V doping produces extra interlayer covalent interactions and additional conducting channels, which increase the electronic conductivity and CT. This gives rapid transport of photo-excited electrons and effective carrier separation in layered SnS2 . Additionally, valence-band photoemission spectra and S K-edge XANES indicate that the density of states near/at valence-band maximum is shifted to lower binding energy in V-doped SnS2 compare to pristine SnS2 and exhibits band gap shrinkage. These findings support first-principles density functional theory calculations of the interstitially tetrahedral OVS site intercalated in the vdW gap, highlighting the CT from V to ligands in V-doped SnS2 .

4.
BMC Biol ; 19(1): 242, 2021 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-34763695

RESUMO

BACKGROUND: Proteostasis unbalance and mitochondrial dysfunction are two hallmarks of aging. While the chaperone folds and activates its clients, it is the cochaperone that determines the specificity of the clients. Ids2 is an HSP90's cochaperone controlling mitochondrial functions, but no in vivo clients of Ids2 have been reported yet. RESULTS: We performed a screen of the databases of HSP90 physical interactors, mitochondrial components, and mutants with respiratory defect, and identified Atp3, a subunit of the complex V ATP synthase, as a client of Ids2. Deletion of IDS2 destabilizes Atp3, and an α-helix at the middle region of Ids2 recruits Atp3 to the folding system. Shortage of Ids2 or Atp3 leads to the loss of mitochondrial DNA. The intermembrane space protease Yme1 is critical to maintaining the Atp3 protein level. Moreover, Ids2 is highly induced when cells carry out oxidative respiration. CONCLUSIONS: These findings discover a cochaperone essentially for maintaining the stability of mitochondrial DNA and the proteostasis of the electron transport chain-crosstalk between two hallmarks of aging.


Assuntos
DNA Mitocondrial , Proteínas de Choque Térmico HSP90 , Trifosfato de Adenosina , DNA Mitocondrial/genética , Proteínas de Choque Térmico HSP90/genética , Humanos , Mitocôndrias , Chaperonas Moleculares/genética
5.
Zhongguo Dang Dai Er Ke Za Zhi ; 24(10): 1092-1097, 2022 Oct 15.
Artigo em Zh | MEDLINE | ID: mdl-36305108

RESUMO

OBJECTIVES: To study the clinical features of children infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: The medical data of 19 children who were diagnosed with SARS-CoV-2 Omicron variant infection from January 28 to March 3, 2022 in Hangzhou were retrospectively reviewed. RESULTS: Among the 19 children, there were 7 boys (37%) and 12 girls (63%), and their age ranged from 6 months to 16 years, with a median age of 2 years and 1 month. Most of these children were infants and young children (aged ≤3 years, accounting for 53%). Among these children, 11 (58%) were unvaccinated with SARS-CoV-2 vaccine and 8 (42%) were vaccinated with SARS-CoV-2 vaccine, and 3 children (16%) had a history of underlying diseases. All 19 children had a clear history of close contact with persons infected with SARS-CoV-2, and 10 children (53%) were involved in the cluster outbreak in a maternal and infant care center. In terms of clinical classification, 13 children (68%) had mild coronavirus disease 2019 (COVID-19) and 6 (32%) had common COVID-19, with no severe cases of COVID-19. The most common clinical symptoms were cough (100%) and fever (63%). The children with a normal peripheral white blood cell count accounted for 84%, and those with a normal lymphocyte count accounted for 68%. There were no significant abnormalities in platelet count, procalcitonin, liver function parameters (alanine aminotransferase and aspartate aminotransferase), and renal function parameters (creatinine and urea). Six children (32%) had obvious signs of pneumonia on chest CT. All 19 children were given symptomatic treatment, and 12 children (63%) were given aerosol inhalation of interferon α. All children were cured and discharged. CONCLUSIONS: Children infected with Omicron variant strains are more common in infants and young children, with mild symptoms and good prognosis. Most of the children have a history of close contact with persons infected with SARS-CoV-2, and epidemic prevention and control should be strengthened in places with many infants and children, such as maternal and infant care centers.


Assuntos
COVID-19 , SARS-CoV-2 , Criança , Lactente , Masculino , Feminino , Humanos , Pré-Escolar , Estudos Retrospectivos , Vacinas contra COVID-19 , China/epidemiologia
6.
J Biomed Sci ; 28(1): 65, 2021 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-34565360

RESUMO

BACKGROUND: Heterozygous pathogenic variants in STUB1 are implicated in autosomal dominant spinocerebellar ataxia type 48 (SCA48), which is a rare familial ataxia disorder. We investigated the clinical, genetic and functional characteristics of STUB1 mutations identified from a Taiwanese ataxia cohort. METHODS: We performed whole genome sequencing in a genetically undiagnosed family with an autosomal dominant ataxia syndrome. Further Sanger sequencing of all exons and intron-exon boundary junctions of STUB1 in 249 unrelated patients with cerebellar ataxia was performed. The pathogenicity of the identified novel STUB1 variant was investigated. RESULTS: We identified a novel heterozygous frameshift variant, c.832del (p.Glu278fs), in STUB1 in two patients from the same family. This rare mutation is located in the U-box of the carboxyl terminus of the Hsc70-interacting protein (CHIP) protein, which is encoded by STUB1. Further in vitro experiments demonstrated that this novel heterozygous STUB1 frameshift variant impairs the CHIP protein's activity and its interaction with the E2 ubiquitin ligase, UbE2D1, leading to neuronal accumulation of tau and α-synuclein, caspase-3 activation, and promoting cellular apoptosis through a dominant-negative pathogenic effect. The in vivo study revealed the influence of the CHIP expression level on the differentiation and migration of cerebellar granule neuron progenitors during cerebellar development. CONCLUSIONS: Our findings provide clinical, genetic, and a mechanistic insight linking the novel heterozygous STUB1 frameshift mutation at the highly conserved U-box domain of CHIP as the cause of autosomal dominant SCA48. Our results further stress the importance of CHIP activity in neuronal protein homeostasis and cerebellar functions.


Assuntos
Mutação da Fase de Leitura , Ataxias Espinocerebelares/genética , Ubiquitina-Proteína Ligases/genética , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Taiwan , Ubiquitina-Proteína Ligases/metabolismo
7.
Nanotechnology ; 31(40): 405605, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-32554895

RESUMO

A fast cyclohexanol solvothermal pathway was developed to prepare highly dispersed anatase titania (TiO2) nanosheets with an edge length of ∼800 nm and a thickness of ∼6 nm. Under the synergistic control of hexafluorotitanic acid and cyclohexanol, the exposed 001 facets reached ∼98.5% on the TiO2 nanosheets obtained by the treatment at 180 °C for 150 min. Moreover, it was found that the phase transformation and structural development drastically occurred during the solvothermal treatment. When used as a catalyst for photodegradation of rhodamine B, the TiO2 nanosheets exhibited a good recycling stability and a much higher photocatalytic degradation rate (nearly 99% degradation within 2.5 h) than the commercial P25 (93.6%). After being uniformly loaded with 4 wt.% of the Pt nanoparticles, the TiO2 nanosheets displayed a photocatalytic hydrogen production rate of 2.239 mmol g-1 h-1 under simulated solar light, which was much higher than the pristine TiO2 nanosheets (0.045 mmol g-1 h-1) as well as most of the reported TiO2-based photocatalysts. The remarkable photocatalytic activity and good stability of the TiO2 nanosheets with highly exposed 001 facets would make them find potential applications in both water treatment and hydrogen generation from water splitting under solar light.

8.
Mol Cell ; 43(5): 811-22, 2011 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-21884981

RESUMO

Epithelial-mesenchymal transition (EMT) is important for organ development, metastasis, cancer stemness, and organ fibrosis. Molecular mechanisms to coordinately regulate hypoxia-induced EMT remain elusive. Here, we show that HIF-1α-induced histone deacetylase 3 (hdac3) is essential for hypoxia-induced EMT and metastatic phenotypes. Change of specific chromatin states is associated with hypoxia-induced EMT. Under hypoxia, HDAC3 interacts with hypoxia-induced WDR5, recruits the histone methyltransferase (HMT) complex to increase histone H3 lysine 4 (H3K4)-specific HMT activity, and activates mesenchymal gene expression. HDAC3 also serves as an essential corepressor to repress epithelial gene expression. Knockdown of WDR5 abolishes mesenchymal gene activation but not epithelial gene repression during hypoxia. These results indicate that hypoxia induces different chromatin modifiers to coordinately regulate EMT through distinct mechanisms.


Assuntos
Transição Epitelial-Mesenquimal/fisiologia , Histona Desacetilases/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Animais , Hipóxia Celular , Células Cultivadas , Transição Epitelial-Mesenquimal/genética , Expressão Gênica , Histona Desacetilases/genética , Histona-Lisina N-Metiltransferase/genética , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Transfecção
9.
Nucleic Acids Res ; 45(14): 8314-8328, 2017 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-28575419

RESUMO

Telomere homeostasis is controlled by both telomerase machinery and end protection. Telomere shortening induces DNA damage sensing kinases ATM/ATR for telomerase recruitment. Yet, whether telomere shortening also governs end protection is poorly understood. Here we discover that yeast ATM/ATR controls end protection. Rap1 is phosphorylated by Tel1 and Mec1 kinases at serine 731, and this regulation is stimulated by DNA damage and telomere shortening. Compromised Rap1 phosphorylation hampers the interaction between Rap1 and its interacting partner Rif1, which thereby disturbs the end protection. As expected, reduction of Rap1-Rif1 association impairs telomere length regulation and increases telomere-telomere recombination. These results indicate that ATM/ATR DNA damage checkpoint signal contributes to telomere protection by strengthening the Rap1-Rif1 interaction at short telomeres, and the checkpoint signal oversees both telomerase recruitment and end capping pathways to maintain telomere homeostasis.


Assuntos
Retroalimentação Fisiológica , Homeostase do Telômero/genética , Encurtamento do Telômero/genética , Telômero/genética , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Western Blotting , Dano ao DNA , Modelos Genéticos , Mutação , Fosforilação , Ligação Proteica , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Serina/genética , Serina/metabolismo , Complexo Shelterina , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/genética , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/metabolismo , Telômero/metabolismo , Proteínas de Ligação a Telômeros/genética , Proteínas de Ligação a Telômeros/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Técnicas do Sistema de Duplo-Híbrido
10.
Nucleic Acids Res ; 45(18): 10492-10503, 2017 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-28985359

RESUMO

Telomerase is highly expressed in cancer and embryonic stem cells (ESCs) and implicated in controlling genome integrity, cancer formation and stemness. Previous studies identified that Krüppel-like transcription factor 4 (KLF4) activates telomerase reverse transcriptase (TERT) expression and contributes to the maintenance of self-renewal in ESCs. However, little is known about how KLF4 regulates TERT expression. Here, we discover poly(ADP-ribose) polymerase 1 (PARP1) as a novel KLF4-interacting partner. Knockdown of PARP1 reduces TERT expression and telomerase activity not only in cancer cells, but also in human and mouse ESCs. Recruitment of KLF4 to TERT promoter is reduced in PARP1-suppressed cells. The poly(ADP-ribose) polymerase activity is dispensable, while the oligo(ADP-ribose) polymerase activity is required for the PARP1- and KLF4-mediated TERT activation. Repression of Parp1 in mouse ESCs decreases expression of pluripotent markers and induces differentiation. These results suggest that PARP1 recruits KLF4 to activate telomerase expression and stem cell pluripotency, indicating a positive regulatory role of the PARP1-KLF4 complex in telomerase expression in cancer and stem cells.


Assuntos
Células-Tronco Embrionárias/metabolismo , Fatores de Transcrição Kruppel-Like/fisiologia , Neoplasias/genética , Poli(ADP-Ribose) Polimerase-1/fisiologia , Telomerase/genética , Animais , Diferenciação Celular/genética , Células Cultivadas , Embrião de Mamíferos , Células-Tronco Embrionárias/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/metabolismo , Camundongos , Neoplasias/patologia , Poli(ADP-Ribose) Polimerase-1/metabolismo , Telomerase/metabolismo
11.
Cell Mol Life Sci ; 72(9): 1825-37, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25430478

RESUMO

Telomere maintenance is required for chromosome stability, and telomeres are typically elongated by telomerase following DNA replication. In both tumor and yeast cells that lack telomerase, telomeres are maintained via an alternative recombination mechanism. Previous studies have indicated that yeast Sgs1 and Top3 may work together to remove highly negative supercoils that are generated from recombination. However, the mechanism by which cells eradicate highly positive supercoils during recombination remains unclear. In the present study, we demonstrate that TOP2 is involved in telomere-telomere recombination. Disturbance of telomeric structure by RIF1 or RIF2 deletion alleviates the requirement for TOP2 in telomere-telomere recombination. In human telomerase-negative alternative lengthening of telomere (ALT) cells, TOP2α or TOP2ß knockdown decreases ALT-associated PML bodies, increases telomere dysfunction-induced foci and triggers telomere shortening. Similar results were observed when ALT cells were treated with ICRF-193, a TOP2 inhibitor. Importantly, ICRF-193 treatment blocks ALT-associated phenotypes in vitro, causes telomere shortening, and inhibits ALT cell proliferation in mice. Taken together, these findings imply that TOP2 is involved in the ALT pathway, perhaps by resolving the highly positive supercoil structure at the front of the helicase. Inhibition of topoisomerase II may be a promising therapeutic approach that can be used to prevent cell proliferation in ALT-type cancer cells.


Assuntos
DNA Topoisomerases Tipo II/metabolismo , Neoplasias/tratamento farmacológico , Piperazinas/uso terapêutico , Telomerase/genética , Inibidores da Topoisomerase II/uso terapêutico , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , DNA Topoisomerases Tipo II/genética , Dicetopiperazinas , Deleção de Genes , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Piperazinas/farmacologia , Homeostase do Telômero/efeitos dos fármacos , Proteínas de Ligação a Telômeros/genética , Proteínas de Ligação a Telômeros/metabolismo , Inibidores da Topoisomerase II/farmacologia
12.
Mol Cell Proteomics ; 13(2): 594-605, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24319056

RESUMO

Degradation of the M phase cyclins triggers the exit from M phase. Cdc14 is the major phosphatase required for the exit from the M phase. One of the functions of Cdc14 is to dephosphorylate and activate the Cdh1/APC/C complex, resulting in the degradation of the M phase cyclins. However, other crucial targets of Cdc14 for mitosis and cytokinesis remain to be elucidated. Here we systematically analyzed the positions of dephosphorylation sites for Cdc14 in the budding yeast Saccharomyces cerevisiae. Quantitative mass spectrometry identified a total of 835 dephosphorylation sites on 455 potential Cdc14 substrates in vivo. We validated two events, and through functional studies we discovered that Cdc14-mediated dephosphorylation of Smc4 and Bud3 is essential for proper mitosis and cytokinesis, respectively. These results provide insight into the Cdc14-mediated pathways for exiting the M phase.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Citocinese , Mitose , Fosfoproteínas/metabolismo , Proteínas Tirosina Fosfatases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Sítios de Ligação , Proteínas Cromossômicas não Histona/metabolismo , Segregação de Cromossomos , Citocinese/genética , Empacotamento do DNA , Mitose/genética , Fosfoproteínas/química , Fosforilação , Processamento de Proteína Pós-Traducional , Proteoma/análise , Proteoma/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Espectrometria de Massas em Tandem
13.
Trends Genet ; 28(9): 454-63, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22717049

RESUMO

The epithelial-mesenchymal transition (EMT) is a developmental process that is important for organ development, metastasis, cancer stemness, and organ fibrosis. The EMT process is regulated by different signaling pathways as well as by various epigenetic and post-transcriptional mechanisms. Here, we review recent progress describing the role of different chromatin modifiers in various signaling events leading to EMT, including hypoxia, transforming growth factor (TGF)-ß, Notch, and Wnt. We also discuss post-transcriptional mechanisms, such as RNA alternative splicing and the effects of miRNAs in EMT regulation. Furthermore, we highlight on-going and future work aimed at a detailed understanding of the epigenetic and post-transcriptional mechanisms that regulate EMT. This work will shed new light on the cellular and tumorigenic processes affected by EMT misregulation.


Assuntos
Reprogramação Celular , Epigênese Genética , Transição Epitelial-Mesenquimal , Processamento Pós-Transcricional do RNA , Animais , Hipóxia Celular , Cromatina/genética , Cromatina/metabolismo , Humanos
14.
J Virol ; 87(1): 110-23, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23055567

RESUMO

Transcription and replication of the influenza A virus RNA genome occur in the nucleus through the viral RNA-dependent RNA polymerase consisting of PB1, PB2, and PA. Cellular factors that associate with the viral polymerase complex play important roles in these processes. To look for cellular factors that could associate with influenza A virus PA protein, we have carried out a yeast two-hybrid screen using a HeLa cell cDNA library. We identified six cellular proteins that may interact with PA. We focused our study on one of the new PA-interacting proteins, HAX1, a protein with antiapoptotic function. By using glutathione S-transferase pulldown and coimmunoprecipitation assays, we demonstrate that HAX1 specifically interacts with PA in vitro and in vivo and that HAX1 interacts with the nuclear localization signal domain of PA. Nuclear accumulation of PA was increased in HAX1-knockdown cells, and this phenotype could be reversed by reexpression of HAX1, indicating that HAX1 can impede nuclear transport of PA. As a consequence, knockdown of HAX1 resulted in a significant increase in virus yield and polymerase activity in a minigenome assay, and this phenotype could be reversed by reexpression of HAX1, indicating that HAX1 can inhibit influenza A virus propagation. Together, these results not only provide insight into the mechanism underlying nuclear transport of PA but also identify an intrinsic host factor that restricts influenza A virus infection.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Interações Hospedeiro-Patógeno , Vírus da Influenza A/enzimologia , Mapeamento de Interação de Proteínas , RNA Polimerase Dependente de RNA/metabolismo , Proteínas Virais/metabolismo , Transporte Ativo do Núcleo Celular , Linhagem Celular , Centrifugação , Humanos , Imunoprecipitação , Ligação Proteica , Técnicas do Sistema de Duplo-Híbrido
15.
CPT Pharmacometrics Syst Pharmacol ; 13(3): 437-448, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38111189

RESUMO

Overall survival is vital for approving new anticancer drugs but is often impractical for early-phase studies. The tumor growth inhibition-overall survival (TGI-OS) model could bridge the gap between early- and late-stage development. This study aimed to identify an appropriate TGI-OS model for patients with non-small cell lung cancer from the GEMSTONE-302 study of sugemalimab. We used three TGI models to delineate tumor trajectories and investigated three OS model for linking TGI metric to OS. All three TGI models accurately captured tumor profiles at the individual level. The published atezolizumab-based TGI-OS model predicted survival time satisfactorily through simulation-based evaluation, whereas the other published model built from multi-treatment underestimated OS. Our study-specific TGI-OS model identified time-to-growth as the most significant metric with the number of metastatic sites and neutrophil-to-lymphocyte ratio at baseline as covariates and exhibited robust OS predictability. Our findings demonstrated the effectiveness of the TGI-OS models in predicting phase III outcomes, which underpins their value as a powerful tool for antitumor drug development.


Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Modelos Teóricos , Simulação por Computador
16.
Parkinsonism Relat Disord ; 109: 105353, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36863113

RESUMO

BACKGROUND: Mitochondrial membrane protein‒associated neurodegeneration (MPAN) is a rare genetic disease characterized by progressive neurodegeneration with brain iron accumulations combined with neuronal α-synuclein and tau aggregations. Mutations in C19orf12 have been associated with both autosomal recessive and autosomal dominant inheritance patterns of MPAN. METHODS: We present clinical features and functional evidence from a Taiwanese family with autosomal dominant MPAN caused by a novel heterozygous frameshift and nonsense mutation in C19orf12, c273_274 insA (p.P92Tfs*9). To verify the pathogenicity of the identified variant, we examined the mitochondrial function, morphology, protein aggregation, neuronal apoptosis, and RNA interactome in p.P92Tfs*9 mutant knock-in SH-SY5Y cells created with CRISPR-Cas9 technology. RESULTS: Clinically, the patients with the C19orf12 p.P92Tfs*9 mutation presented with generalized dystonia, retrocollis, cerebellar ataxia, and cognitive decline, starting in their mid-20s. The identified novel frameshift mutation is located in the evolutionarily conserved region of the last exon of C19orf12. In vitro studies revealed that the p.P92Tfs*9 variant is associated with impaired mitochondrial function, reduced ATP production, aberrant mitochondria interconnectivity and ultrastructure. Increased neuronal α-synuclein and tau aggregations, and apoptosis were observed under conditions of mitochondrial stress. Transcriptomic analysis revealed that the expression of genes in clusters related to mitochondrial fission, lipid metabolism, and iron homeostasis pathways was altered in the C19orf12 p.P92Tfs*9 mutant cells compared to control cells. CONCLUSION: Our findings provide clinical, genetic, and mechanistic insight revealing a novel heterozygous C19orf12 frameshift mutation to be a cause of autosomal dominant MPAN, further strengthening the importance of mitochondrial dysfunction in the pathogenesis of MPAN.


Assuntos
Mutação da Fase de Leitura , Neuroblastoma , Humanos , Mutação da Fase de Leitura/genética , alfa-Sinucleína/genética , Linhagem , Proteínas Mitocondriais/genética , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mutação , Proteínas de Membrana/genética , Ferro/metabolismo
17.
CPT Pharmacometrics Syst Pharmacol ; 12(9): 1347-1357, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37528543

RESUMO

As a result of the escalating number of new cancer treatments being developed and competition among pharmaceutical companies, decisions regarding how to proceed with phase III trials are frequently based on findings from either single-arm phase I expansion cohorts or phase II studies that compare the efficacy of the study drug to a standard-of-care benchmark derived from historical data. However, even when eligibility criteria are matched, differences in the distribution of baseline patient features may influence the outcome of single-arm trials in real-world scenarios. Therefore, novel methods are needed to enhance the accuracy of efficacy prediction from current cohorts relative to historical data. In this study, we demonstrated the feasibility of using the propensity score matching (PSM) method to improve decision making by matching relevant baseline features between current and historical cohorts. According to our findings, utilizing the PSM method may provide a less biased means of comparing outcomes between current and historical cohorts relative to a naïve approach, which relies solely on differences in average outcomes between the cohorts.


Assuntos
Oncologia , Pontuação de Propensão , Humanos , Ensaios Clínicos Fase III como Assunto
18.
Arch Pathol Lab Med ; 147(3): 348-358, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35738007

RESUMO

CONTEXT.­: Bone marrow (BM) samples are obtained through aspiration and trephine biopsy. Hemophagocytic lymphohistiocytosis (HLH) has been largely studied in BM aspirate smears. OBJECTIVE.­: To investigate the histologic features of HLH in trephine biopsy. DESIGN.­: Patients with hemophagocytosis in BM aspirate smears were assigned to HLH (n = 127) and non-HLH (n = 203) groups. We quantified hematoxylin-eosin and CD68 immunohistochemical staining of their trephine biopsies. RESULTS.­: No significant correlation was noted in the hemophagocytosis count between aspirate smears and trephine biopsies. Compared with the non-HLH group, the HLH group had a higher hemophagocytosis count (13 versus 9 per tissue section, P = .046), lower percentage of the adipocytic area (36.7% versus 50.3%, P < .001), and higher percentage of the foamy area (19.1% versus 14.5%, P < .001). The HLH group had more histiocyte infiltrates (total histiocyte density, 9.2% versus 7.3%; P < .001) and more fat-infiltrating histiocytes (histiocyte density of the fat-associated part [HD-FA], 7.6% versus 6.2%; P < .001). We identified the following poor prognostic factors in the HLH group: age 50 years or older (median overall survival [mOS], 95 versus 499 days; P = .04), Epstein-Barr virus-positive T-cell lymphoproliferative diseases (EBV+TLPDs) (mOS, 51 versus 425 days; P < .001), hemophagocytosis count of 6 or higher per tissue section (mOS, 66 versus 435 days; P = .02), and HD-FA of 9% or greater (mOS, 61 versus 359 days; P = .02). Multivariate analysis revealed that age 50 years or older (hazard ratio [HR], 2.38; P < .001), EBV+TLPDs (HR, 2.07; P < .001), and hemophagocytosis count of 6 or higher per tissue section (HR, 2.07; P = .002) were independent prognostic factors for HLH. CONCLUSIONS.­: The HLH group had higher hemophagocytic activity, higher cellularity, a more foamy appearance, more histiocyte infiltrates, and more fat-infiltrating histiocytes. High hemophagocytic activity and marked histiocyte infiltrates in the BM fat were associated with poorer prognosis.


Assuntos
Infecções por Vírus Epstein-Barr , Linfo-Histiocitose Hemofagocítica , Humanos , Pessoa de Meia-Idade , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/patologia , Infecções por Vírus Epstein-Barr/patologia , Medula Óssea/patologia , Herpesvirus Humano 4 , Biópsia
19.
J Neurosci ; 31(41): 14600-10, 2011 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-21994376

RESUMO

Orexin A and B are hypothalamic peptides known to modulate arousal, feeding, and reward via OX1 and OX2 receptors. Orexins are also antinociceptive in the brain, but their mechanism(s) of action remain unclear. Here, we investigated the antinociceptive mechanism of orexin A in the rat ventrolateral periaqueductal gray (vlPAG), a midbrain region crucial for initiating descending pain inhibition. In vlPAG slices, orexin A (30-300 nm) depressed GABAergic evoked IPSCs. This effect was blocked by an OX1 [1-(2-methylbenzoxazol-6-yl)-3-[1,5]naphthyridin-4-yl urea (SB 334867)], but not OX2 [N-acyl 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline hydrochloride (compound 29)], antagonist. Orexin A increased the paired-pulse ratio of paired IPSCs and decreased the frequency, but not amplitude, of miniature IPSCs. Orexin A-induced IPSC depression was mimicked by (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-napthalenylmethanone (WIN 55,212-2), a cannabinoid 1 (CB1) receptor agonist. 1-(2,4-Dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-(1-piperidyl)pyrazole-3-carboxamide (AM 251), a CB1 antagonist, reversed depressant effects by both agonists. Orexin A-induced IPSC depression was prevented by 1-[6-[[(17ß)-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U73122) and tetrahydrolipstatin, inhibitors of phospholipase C (PLC) and diacylglycerol lipase (DAGL), respectively, and enhanced by cyclohexyl[1,1'-biphenyl]-3-ylcarbamate (URB602), which inhibits enzymatic degradation of 2-arachidonoylglycerol (2-AG). Moderate DAGLα, but not DAGLß, immunoreactivity was observed in the vlPAG. Orexin A produced an overall excitatory effect on evoked postsynaptic potentials and hence increased vlPAG neuronal activity. Intra-vlPAG microinjection of orexin A reduced hot-plate nociceptive responses in rats in a manner blocked by SB 334867 and AM 251. Therefore, orexin A may produce antinociception by activating postsynaptic OX1 receptors, stimulating synthesis of 2-AG, an endocannabinoid, through a Gq-protein-mediated PLC-DAGLα enzymatic cascade culminating in retrograde inhibition of GABA release (disinhibition) in the vlPAG.


Assuntos
Ácidos Araquidônicos/farmacologia , Moduladores de Receptores de Canabinoides/farmacologia , Endocanabinoides , Glicerídeos/farmacologia , Inibição Neural/fisiologia , Dor/tratamento farmacológico , Substância Cinzenta Periaquedutal/fisiologia , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Neuropeptídeos/metabolismo , Análise de Variância , Animais , Animais Recém-Nascidos , Benzoxazinas/farmacologia , Benzoxazóis/farmacologia , Compostos de Bifenilo/farmacologia , Bloqueadores dos Canais de Cálcio , Modelos Animais de Doenças , Estimulação Elétrica , Inibidores Enzimáticos/farmacologia , Estrenos/farmacologia , Técnicas In Vitro , Potenciais Pós-Sinápticos Inibidores/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lactonas/farmacologia , Masculino , Morfolinas/farmacologia , Naftalenos/farmacologia , Naftiridinas , Inibição Neural/efeitos dos fármacos , Vias Neurais/efeitos dos fármacos , Vias Neurais/fisiologia , Neuropeptídeos/metabolismo , Receptores de Orexina , Orexinas , Orlistate , Dor/metabolismo , Dor/patologia , Medição da Dor/efeitos dos fármacos , Técnicas de Patch-Clamp , Substância Cinzenta Periaquedutal/efeitos dos fármacos , Piperidinas/farmacologia , Pirazóis/farmacologia , Pirrolidinonas/farmacologia , Ratos , Ratos Wistar , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores de Neuropeptídeos/antagonistas & inibidores , Ureia/análogos & derivados , Ureia/farmacologia , Ácido gama-Aminobutírico/metabolismo
20.
RNA ; 16(11): 2085-93, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20817754

RESUMO

Inter- and intragenic noncoding transcription is widespread in eukaryotic genomes; however, the purpose of these types of transcription is still poorly understood. Here, we show that intragenic sense-oriented transcription within the budding yeast ASP3 coding region regulates a constitutively and immediately accessible promoter for the transcription of full-length ASP3. Expression of this short intragenic transcript is independent of GATA transcription factors, which are essential for the activation of full-length ASP3, and independent of RNA polymerase II (RNAPII). Furthermore, we found that an intragenic control element is required for the expression of this noncoding RNA (ncRNA). Continuous expression of the short ncRNA maintains a high level of trimethylation of histone H3 at lysine 4 (H3K4me3) at the ASP3 promoter and makes this region more accessible for RNAPII to transcribe the full-length ASP3. Our results show for the first time that intragenic noncoding transcription promotes gene expression.


Assuntos
Regulação Fúngica da Expressão Gênica , RNA não Traduzido/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Transcrição Gênica , Montagem e Desmontagem da Cromatina , Fatores de Transcrição GATA/genética , Fatores de Transcrição GATA/metabolismo , Fases de Leitura Aberta , Regiões Promotoras Genéticas , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
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