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1.
Cell ; 185(9): 1539-1548.e5, 2022 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-35429436

RESUMO

Virus-like particle (VLP) and live virus assays were used to investigate neutralizing immunity against Delta and Omicron SARS-CoV-2 variants in 259 samples from 128 vaccinated individuals. Following Delta breakthrough infection, titers against WT rose 57-fold and 3.1-fold compared with uninfected boosted and unboosted individuals, respectively, versus only a 5.8-fold increase and 3.1-fold decrease for Omicron breakthrough infection. Among immunocompetent, unboosted patients, Delta breakthrough infections induced 10.8-fold higher titers against WT compared with Omicron (p = 0.037). Decreased antibody responses in Omicron breakthrough infections relative to Delta were potentially related to a higher proportion of asymptomatic or mild breakthrough infections (55.0% versus 28.6%, respectively), which exhibited 12.3-fold lower titers against WT compared with moderate to severe infections (p = 0.020). Following either Delta or Omicron breakthrough infection, limited variant-specific cross-neutralizing immunity was observed. These results suggest that Omicron breakthrough infections are less immunogenic than Delta, thus providing reduced protection against reinfection or infection from future variants.


Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Neutralizantes , Anticorpos Antivirais , Vacina BNT162 , COVID-19/imunologia , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos
2.
Cell ; 184(25): 6022-6036.e18, 2021 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-34838159

RESUMO

Viral-deletion mutants that conditionally replicate and inhibit the wild-type virus (i.e., defective interfering particles, DIPs) have long been proposed as single-administration interventions with high genetic barriers to resistance. However, theories predict that robust, therapeutic DIPs (i.e., therapeutic interfering particles, TIPs) must conditionally spread between cells with R0 >1. Here, we report engineering of TIPs that conditionally replicate with SARS-CoV-2, exhibit R0 >1, and inhibit viral replication 10- to 100-fold. Inhibition occurs via competition for viral replication machinery, and a single administration of TIP RNA inhibits SARS-CoV-2 sustainably in continuous cultures. Strikingly, TIPs maintain efficacy against neutralization-resistant variants (e.g., B.1.351). In hamsters, both prophylactic and therapeutic intranasal administration of lipid-nanoparticle TIPs durably suppressed SARS-CoV-2 by 100-fold in the lungs, reduced pro-inflammatory cytokine expression, and prevented severe pulmonary edema. These data provide proof of concept for a class of single-administration antivirals that may circumvent current requirements to continually update medical countermeasures against new variants.


Assuntos
Tratamento Farmacológico da COVID-19 , Vírus Defeituosos Interferentes/metabolismo , Replicação Viral/efeitos dos fármacos , Animais , Antivirais/farmacologia , COVID-19/metabolismo , Linhagem Celular , Chlorocebus aethiops , Meios de Cultivo Condicionados/farmacologia , Vírus Defeituosos Interferentes/patogenicidade , Sistemas de Liberação de Medicamentos/métodos , Células Epiteliais , Humanos , Masculino , Mesocricetus , Nanopartículas/uso terapêutico , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/metabolismo , SARS-CoV-2/patogenicidade , Células Vero
3.
Cell ; 184(2): 323-333.e9, 2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33306959

RESUMO

The December 2019 outbreak of a novel respiratory virus, SARS-CoV-2, has become an ongoing global pandemic due in part to the challenge of identifying symptomatic, asymptomatic, and pre-symptomatic carriers of the virus. CRISPR diagnostics can augment gold-standard PCR-based testing if they can be made rapid, portable, and accurate. Here, we report the development of an amplification-free CRISPR-Cas13a assay for direct detection of SARS-CoV-2 from nasal swab RNA that can be read with a mobile phone microscope. The assay achieved ∼100 copies/µL sensitivity in under 30 min of measurement time and accurately detected pre-extracted RNA from a set of positive clinical samples in under 5 min. We combined crRNAs targeting SARS-CoV-2 RNA to improve sensitivity and specificity and directly quantified viral load using enzyme kinetics. Integrated with a reader device based on a mobile phone, this assay has the potential to enable rapid, low-cost, point-of-care screening for SARS-CoV-2.


Assuntos
Teste de Ácido Nucleico para COVID-19/métodos , Telefone Celular/instrumentação , Imagem Óptica/métodos , RNA Viral/análise , Carga Viral/métodos , Animais , Teste de Ácido Nucleico para COVID-19/economia , Teste de Ácido Nucleico para COVID-19/instrumentação , Sistemas CRISPR-Cas , Linhagem Celular , Proteínas do Nucleocapsídeo de Coronavírus/genética , Humanos , Nasofaringe/virologia , Imagem Óptica/instrumentação , Fosfoproteínas/genética , Testes Imediatos , Interferência de RNA , RNA Viral/genética , Sensibilidade e Especificidade , Carga Viral/economia , Carga Viral/instrumentação
4.
Cell ; 184(13): 3426-3437.e8, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-33991487

RESUMO

We identified an emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant by viral whole-genome sequencing of 2,172 nasal/nasopharyngeal swab samples from 44 counties in California, a state in the western United States. Named B.1.427/B.1.429 to denote its two lineages, the variant emerged in May 2020 and increased from 0% to >50% of sequenced cases from September 2020 to January 2021, showing 18.6%-24% increased transmissibility relative to wild-type circulating strains. The variant carries three mutations in the spike protein, including an L452R substitution. We found 2-fold increased B.1.427/B.1.429 viral shedding in vivo and increased L452R pseudovirus infection of cell cultures and lung organoids, albeit decreased relative to pseudoviruses carrying the N501Y mutation common to variants B.1.1.7, B.1.351, and P.1. Antibody neutralization assays revealed 4.0- to 6.7-fold and 2.0-fold decreases in neutralizing titers from convalescent patients and vaccine recipients, respectively. The increased prevalence of a more transmissible variant in California exhibiting decreased antibody neutralization warrants further investigation.


Assuntos
Anticorpos Neutralizantes/imunologia , COVID-19/imunologia , COVID-19/transmissão , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Humanos , Mutação/genética , Sequenciamento Completo do Genoma/métodos
5.
Nature ; 607(7918): 351-355, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35584773

RESUMO

SARS-CoV-2 Delta and Omicron are globally relevant variants of concern. Although individuals infected with Delta are at risk of developing severe lung disease, infection with Omicron often causes milder symptoms, especially in vaccinated individuals1,2. The question arises of whether widespread Omicron infections could lead to future cross-variant protection, accelerating the end of the pandemic. Here we show that without vaccination, infection with Omicron induces a limited humoral immune response in mice and humans. Sera from mice overexpressing the human ACE2 receptor and infected with Omicron neutralize only Omicron, but not other variants of concern, whereas broader cross-variant neutralization was observed after WA1 and Delta infections. Unlike WA1 and Delta, Omicron replicates to low levels in the lungs and brains of infected animals, leading to mild disease with reduced expression of pro-inflammatory cytokines and diminished activation of lung-resident T cells. Sera from individuals who were unvaccinated and infected with Omicron show the same limited neutralization of only Omicron itself. By contrast, Omicron breakthrough infections induce overall higher neutralization titres against all variants of concern. Our results demonstrate that Omicron infection enhances pre-existing immunity elicited by vaccines but, on its own, may not confer broad protection against non-Omicron variants in unvaccinated individuals.


Assuntos
COVID-19 , Proteção Cruzada , SARS-CoV-2 , Vacinação , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , Vacinas contra COVID-19/administração & dosagem , Proteção Cruzada/imunologia , Citocinas , Humanos , Camundongos , SARS-CoV-2/classificação , SARS-CoV-2/imunologia , Vacinação/estatística & dados numéricos
6.
Proc Natl Acad Sci U S A ; 119(31): e2200592119, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35858386

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant contains extensive sequence changes relative to the earlier-arising B.1, B.1.1, and Delta SARS-CoV-2 variants that have unknown effects on viral infectivity and response to existing vaccines. Using SARS-CoV-2 virus-like particles (VLPs), we examined mutations in all four structural proteins and found that Omicron and Delta showed 4.6-fold higher luciferase delivery overall relative to the ancestral B.1 lineage, a property conferred mostly by enhancements in the S and N proteins, while mutations in M and E were mostly detrimental to assembly. Thirty-eight antisera samples from individuals vaccinated with Pfizer/BioNTech, Moderna, or Johnson & Johnson vaccines and convalescent sera from unvaccinated COVID-19 survivors had 15-fold lower efficacy to prevent cell transduction by VLPs containing the Omicron mutations relative to the ancestral B.1 spike protein. A third dose of Pfizer vaccine elicited substantially higher neutralization titers against Omicron, resulting in detectable neutralizing antibodies in eight out of eight subjects compared to one out of eight preboosting. Furthermore, the monoclonal antibody therapeutics casirivimab and imdevimab had robust neutralization activity against B.1 and Delta VLPs but no detectable neutralization of Omicron VLPs, while newly authorized bebtelovimab maintained robust neutralization across variants. Our results suggest that Omicron has similar assembly efficiency and cell entry compared to Delta and that its rapid spread is due mostly to reduced neutralization in sera from previously vaccinated subjects. In addition, most currently available monoclonal antibodies will not be useful in treating Omicron-infected patients with the exception of bebtelovimab.


Assuntos
Anticorpos Monoclonais Humanizados , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19 , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêutico , COVID-19/terapia , COVID-19/virologia , Humanos , Mutação , SARS-CoV-2/genética , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus/genética
7.
PLoS Genet ; 15(8): e1007980, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31381576

RESUMO

Synaptic structure and activity are sensitive to environmental alterations. Modulation of synaptic morphology and function is often induced by signals from glia. However, the process by which glia mediate synaptic responses to environmental perturbations such as hypoxia remains unknown. Here, we report that, in the mutant for Trachealess (Trh), the Drosophila homolog for NPAS1 and NPAS3, smaller synaptic boutons form clusters named satellite boutons appear at larval neuromuscular junctions (NMJs), which is induced by the reduction of internal oxygen levels due to defective tracheal branches. Thus, the satellite bouton phenotype in the trh mutant is suppressed by hyperoxia, and recapitulated in wild-type larvae raised under hypoxia. We further show that hypoxia-inducible factor (HIF)-1α/Similar (Sima) is critical in mediating hypoxia-induced satellite bouton formation. Sima upregulates the level of the Wnt/Wingless (Wg) signal in glia, leading to reorganized microtubule structures within presynaptic sites. Finally, hypoxia-induced satellite boutons maintain normal synaptic transmission at the NMJs, which is crucial for coordinated larval locomotion.


Assuntos
Hipóxia Celular/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Junção Neuromuscular/crescimento & desenvolvimento , Transmissão Sináptica/fisiologia , Fatores de Transcrição/metabolismo , Animais , Animais Geneticamente Modificados , Proteínas de Drosophila/genética , Drosophila melanogaster/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Microscopia Intravital , Larva/fisiologia , Locomoção/genética , Microscopia Confocal , Microtúbulos/metabolismo , Modelos Animais , Neuroglia/citologia , Neuroglia/metabolismo , Junção Neuromuscular/metabolismo , Terminações Pré-Sinápticas/metabolismo , Transdução de Sinais/genética , Fatores de Transcrição/genética , Regulação para Cima , Proteína Wnt1/metabolismo
8.
Proc Natl Acad Sci U S A ; 116(49): 24651-24661, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31666321

RESUMO

Secreted exosomal microRNAs (miRNAs) mediate interorgan/tissue communications by modulating target gene expression, thereby regulating developmental and physiological functions. However, the source, route, and function in target cells have not been formally established for specific miRNAs. Here, we show that glial miR-274 non-cell-autonomously modulates the growth of synaptic boutons and tracheal branches. Whereas the precursor form of miR-274 is expressed in glia, the mature form of miR-274 distributes broadly, including in synaptic boutons, muscle cells, and tracheal cells. Mature miR-274 is secreted from glia to the circulating hemolymph as an exosomal cargo, a process requiring ESCRT components in exosome biogenesis and Rab11 and Syx1A in exosome release. We further show that miR-274 can function in the neurons or tracheal cells to modulate the growth of synaptic boutons and tracheal branches, respectively. Also, miR-274 uptake into the target cells by AP-2-dependent mechanisms modulates target cell growth. In the target cells, miR-274 down-regulates Sprouty (Sty) through a targeting sequence at the sty 3' untranslated region, thereby enhancing MAPK signaling and promoting cell growth. miR-274 expressed in glia of an mir-274 null mutant is released as an exosomal cargo in the circulating hemolymph, and such glial-specific expression resets normal levels of Sty and MAPK signaling and modulates target cell growth. mir-274 mutant larvae are hypersensitive to hypoxia, which is suppressed by miR-274 expression in glia or by increasing tracheal branches. Thus, glia-derived miR-274 coordinates growth of synaptic boutons and tracheal branches to modulate larval hypoxia responses.


Assuntos
Proteínas de Drosophila/genética , Drosophila melanogaster/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteínas de Membrana/genética , MicroRNAs/metabolismo , Neuroglia/metabolismo , Regiões 3' não Traduzidas/genética , Animais , Animais Geneticamente Modificados , Hipóxia Celular/genética , Regulação para Baixo , Exossomos/metabolismo , Feminino , Hemolinfa/metabolismo , Larva/crescimento & desenvolvimento , Larva/metabolismo , Sistema de Sinalização das MAP Quinases/genética , MicroRNAs/genética , Mutação , Terminações Pré-Sinápticas/metabolismo , Precursores de RNA/genética , Precursores de RNA/metabolismo , Traqueia/crescimento & desenvolvimento , Traqueia/metabolismo , Regulação para Cima
9.
Int J Mol Sci ; 23(20)2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36293338

RESUMO

Nobiletin, a dietary citrus flavonoid, exerts biological activities against hyperlipidemia, obesity, and atherosclerotic cardiovascular diseases (ASCVDs). The aim of this study was to explore the lipid-lowering effects of nobiletin and the underlying molecular mechanisms in vitro in hepatic cells and in vivo in zebrafish models. Transcriptome and gene ontology (GO) analyses of differentially expressed genes (DEGs) by gene set enrichment analysis (GSEA) showed that a set of twenty-eight core enrichment DEGs associated with "GO BP regulation of lipid metabolic process" (GO: 0019216) were significantly downregulated in nobiletin-treated cells. Among these genes, angiopoietin-like 3 (ANGPTL3), an inhibitor of lipoprotein lipase (LPL) activity that regulates TG-rich lipoprotein (TGRL) metabolism in circulation, was the protein most markedly downregulated by nobiletin. Nobiletin (20 and 40 µM) significantly reduced the levels of ANGPTL3 mRNA and intracellular and secreted ANGPTL3 proteins in hepatic cell lines. Furthermore, alleviation of secreted ANGPTL3 production by nobiletin was found to reinstate LPL catalytic activity. Nobiletin significantly inhibited ANGPTL3 promoter activity and attenuated the transcription factor liver X receptor-α (LXRα)-mediated ANGPTL3 transcription. Molecular docking analysis predicted that nobiletin could bind to the ligand-binding domain of LXRα, thereby counteracting LXRα activation. In animal studies, orally administered nobiletin significantly alleviated the levels of plasma triglycerides (TGs) and cholesterol in zebrafish fed a high-fat diet. Moreover, nobiletin significantly reduced the amounts of hepatic ANGPTL3 protein in zebrafish. Our findings suggest that nobiletin may regulate the LXRα-ANGPTL3-LPL axis and exhibit lipid-modulating effects in vitro and in vivo. Thus, nobiletin is a potential ANGPTL3 inhibitor for the regulation of lipid metabolism to ameliorate dyslipidemia and ASCVDs.


Assuntos
Proteína 3 Semelhante a Angiopoietina , Citrus , Animais , Proteínas Semelhantes a Angiopoietina/genética , Proteínas Semelhantes a Angiopoietina/metabolismo , Lipase Lipoproteica/metabolismo , Peixe-Zebra/genética , Receptores X do Fígado/genética , Flavonoides/farmacologia , Citrus/metabolismo , Simulação de Acoplamento Molecular , Ligantes , Triglicerídeos/metabolismo , Hepatócitos/metabolismo , Angiopoietinas/metabolismo , Lipoproteínas , RNA Mensageiro , Fatores de Transcrição
10.
Int J Mol Sci ; 23(13)2022 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-35806401

RESUMO

Acute myeloid leukemia (AML) is characterized by the dysregulation of hematopoietic cell proliferation, resulting in the accumulation of immature myeloid cells in bone marrow. 5-Demethylnobiletin (5-demethyl NOB), a citrus 5-hydroxylated polymethoxyflavone, has been reported to exhibit various bioactivities, such as antioxidant, anti-inflammatory and anticancer properties. In this study, we investigated the antileukemic effects of 5-demethyl NOB and its underlying molecular mechanisms in human AML cells. We found that 5-demethyl NOB (20−80 µM) significantly reduced human leukemia cell viability, and the following trend of effectiveness was observed: THP-1 ≈ U-937 > HEL > HL-60 > K562 cells. 5-Demethyl NOB (20 and 40 µM) modulated the cell cycle through the regulation of p21, cyclin E1 and cyclin A1 expression and induced S phase arrest. 5-Demethyl NOB also promoted leukemia cell apoptosis and differentiation. Microarray-based transcriptome, Gene Ontology (GO) and Gene Set Enrichment Analysis (GSEA) of differentially expressed genes (DEGs) analysis showed that the expression of inhibitor of differentiation/DNA binding 1 (ID1), a gene associated with the GO biological process (BP) cell population proliferation (GO: 0008283), was most strongly suppressed by 5-demethyl NOB (40 µM) in THP-1 cells. We further demonstrated that 5-demethyl NOB-induced ID1 reduction was associated with the inhibition of leukemia cell growth. Moreover, DEGs involved in the hallmark gene set NF-κB/TNF-α signaling pathway were markedly enriched and downregulated by 5-demethyl NOB. Finally, we demonstrated that 5-demethyl NOB (20 and 40 µM), combined with cytarabine, synergistically reduced THP-1 and U-937 cell viability. Our current findings support that 5-demethyl NOB dramatically suppresses leukemia cell proliferation and may serve as a potential phytochemical for human AML chemotherapy.


Assuntos
Flavonas , Proteína 1 Inibidora de Diferenciação , Leucemia Mieloide Aguda , NF-kappa B , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Flavonas/farmacologia , Humanos , Proteína 1 Inibidora de Diferenciação/biossíntese , Proteína 1 Inibidora de Diferenciação/genética , Proteína 1 Inibidora de Diferenciação/metabolismo , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia
11.
Int J Mol Sci ; 22(14)2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34298929

RESUMO

Dyslipidemia is characterized by increasing plasma levels of low-density lipoprotein-cholesterol (LDL-C), triglycerides (TGs) and TG-rich lipoproteins (TGRLs) and is a major risk factor for the development of atherosclerotic cardiovascular disorders (ASCVDs). It is important to understand the metabolic mechanisms underlying dyslipidemia to develop effective strategies against ASCVDs. Angiopoietin-like 3 (ANGPTL3), a member of the angiopoietin-like protein family exclusively synthesized in the liver, has been demonstrated to be a critical regulator of lipoprotein metabolism to inhibit lipoprotein lipase (LPL) activity. Genetic, biochemical, and clinical studies in animals and humans have shown that loss of function, inactivation, or downregulated expression of ANGPTL3 is associated with an obvious reduction in plasma levels of TGs, LDL-C, and high-density lipoprotein-cholesterol (HDL-C), atherosclerotic lesions, and the risk of cardiovascular events. Therefore, ANGPTL3 is considered an alternative target for lipid-lowering therapy. Emerging studies have focused on ANGPTL3 inhibition via antisense oligonucleotides (ASOs) and monoclonal antibody-based therapies, which have been carried out in mouse or monkey models and in human clinical studies for the management of dyslipidemia and ASCVDs. This review will summarize the current literature on the important role of ANGPTL3 in controlling lipoprotein metabolism and dyslipidemia, with an emphasis on anti-ANGPTL3 therapies as a potential strategy for the treatment of dyslipidemia and ASCVDs.


Assuntos
Proteínas Semelhantes a Angiopoietina/metabolismo , Dislipidemias/metabolismo , Lipoproteínas/metabolismo , Animais , Aterosclerose/metabolismo , HDL-Colesterol/metabolismo , LDL-Colesterol , Humanos , Triglicerídeos/metabolismo
12.
Int J Mol Sci ; 22(18)2021 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-34576019

RESUMO

The excessive accumulation of TG-rich lipoproteins (TGRLs) in plasma is associated with dyslipidemia and atherosclerotic cardiovascular diseases (ASCVDs). Tangeretin is a bioactive pentamethoxyflavone mainly found in citrus peels, and it has been reported to protect against hyperlipidemia, diabetes, and obesity. The aim of this study was to investigate the lipid-modulating effects and the underlying mechanisms of tangeretin action in hepatic cells. Transcriptome and bioinformatics analyses with the Gene Ontology (GO) database showed that tangeretin significantly regulated a set of 13 differentially expressed genes (DEGs) associated with the regulation of lipoprotein lipase (LPL) activity. Among these DEGs, angiopoietin-like 3 (ANGPTL3), an essential inhibitor of LPL catalytic activity that regulates TGRL metabolism in plasma, was markedly downregulated by tangeretin. We demonstrated that tangeretin significantly inhibited the mRNA expression of ANGPTL3 in HepG2 and Huh-7 cells. Tangeretin treatment of hepatic cells also reduced the levels of both intracellular and secreted ANGPTL3 proteins. Moreover, we found that inhibition of ANGPTL3 production by tangeretin augmented LPL activity. We further demonstrated that the transcriptional activity of the ANGPTL3 promoter was significantly attenuated by tangeretin, and we identified a DNA element located between the -250 and -121 positions that responded to tangeretin. Furthermore, we found that tangeretin did not alter the levels of the nuclear liver X receptor α (LXRα) protein, an essential transcription factor that binds to the tangeretin-responsive element, but it can counteract LXRα-mediated ANGPTL3 transcription. On the basis of molecular docking analysis, tangeretin was predicted to bind to the ligand-binding domain of LXRα, which would result in suppression of LXRα activation. Our findings support the hypothesis that tangeretin exerts a lipid-lowering effect by modulating the LXRα-ANGPTL3-LPL pathway, and thus, it can be used as a potential phytochemical for the prevention or treatment of dyslipidemia.


Assuntos
Proteínas Semelhantes a Angiopoietina/antagonistas & inibidores , Flavonas/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Receptores X do Fígado/metabolismo , Proteína 3 Semelhante a Angiopoietina , Proteínas Semelhantes a Angiopoietina/metabolismo , Avaliação Pré-Clínica de Medicamentos , Dislipidemias/tratamento farmacológico , Flavonas/uso terapêutico , Células Hep G2 , Humanos , Lipase/metabolismo
13.
Bioorg Chem ; 98: 103689, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32171993

RESUMO

In an effort to develop new cancer therapeutics, we have reported clinical candidate BPR1K871 (1) as a potentanticancercompound in MOLM-13 and MV4-11 leukemia models, as well as in colorectal and pancreatic animal models. As BPR1K871 lacks oral bioavailability, we continued searching for orally bioavailable analogs through drug-like property optimization. We optimized both the physicochemical properties (PCP) as well as in vitro rat liver microsomal stability of 1, with concomitant monitoring of aurora kinase enzyme inhibition as well as cellular anti-proliferative activity in HCT-116 cell line. Structural modification at the 6- and 7-position of quinazoline core of 1 led to the identification of 34 as an orally bioavailable (F% = 54) multi-kinase inhibitor, which exhibits potent anti-proliferative activity against various cancer cell lines. Quinazoline 34 is selected as a promising oral lead candidate for further preclinical evaluation.


Assuntos
Antineoplásicos/farmacologia , Aurora Quinases/antagonistas & inibidores , Descoberta de Drogas , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacologia , Administração Oral , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Aurora Quinases/metabolismo , Disponibilidade Biológica , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HCT116 , Humanos , Masculino , Estrutura Molecular , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/química , Quinazolinas/administração & dosagem , Quinazolinas/química , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade
14.
PLoS Genet ; 12(10): e1006362, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27736876

RESUMO

In response to environmental and physiological changes, the synapse manifests plasticity while simultaneously maintains homeostasis. Here, we analyzed mutant synapses of henji, also known as dbo, at the Drosophila neuromuscular junction (NMJ). In henji mutants, NMJ growth is defective with appearance of satellite boutons. Transmission electron microscopy analysis indicates that the synaptic membrane region is expanded. The postsynaptic density (PSD) houses glutamate receptors GluRIIA and GluRIIB, which have distinct transmission properties. In henji mutants, GluRIIA abundance is upregulated but that of GluRIIB is not. Electrophysiological results also support a GluR compositional shift towards a higher IIA/IIB ratio at henji NMJs. Strikingly, dPAK, a positive regulator for GluRIIA synaptic localization, accumulates at the henji PSD. Reducing the dpak gene dosage suppresses satellite boutons and GluRIIA accumulation at henji NMJs. In addition, dPAK associated with Henji through the Kelch repeats which is the domain essential for Henji localization and function at postsynapses. We propose that Henji acts at postsynapses to restrict both presynaptic bouton growth and postsynaptic GluRIIA abundance by modulating dPAK.


Assuntos
Proteínas de Drosophila/genética , Junção Neuromuscular/genética , Receptores de Glutamato/genética , Receptores Ionotrópicos de Glutamato/genética , Sinapses/genética , Quinases Ativadas por p21/genética , Animais , Moléculas de Adesão Celular Neuronais/genética , Drosophila melanogaster/genética , Drosophila melanogaster/ultraestrutura , Repetição Kelch/genética , Microscopia Eletrônica de Transmissão , Junção Neuromuscular/ultraestrutura , Terminações Pré-Sinápticas/metabolismo , Sinapses/ultraestrutura , Transmissão Sináptica/genética
15.
Molecules ; 24(3)2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30704067

RESUMO

Pigeon pea (Cajanus cajan (L.) Millsp.) is a legume crop consumed as an indigenous vegetable in the human diet and a traditional medicinal plant with therapeutic properties. The current study highlights the cholesterol-modulating effect and underlying mechanisms of the methanol extract of Cajanus cajan L. leaves (MECC) in HepG2 cells. We found that MECC increased the LDLR expression, the cell-surface LDLR levels and the LDL uptake activity in HepG2 cells. We further demonstrated that MECC suppressed the proprotein convertase subtilisin/kexin type 9 (PCSK9) mRNA and protein expression, but not affected the expression of other cholesterol or lipid metabolism-related genes including inducible degrader of LDLR (IDOL), HMG-CoA reductase (HMGCR), fatty acid synthase (FASN), acetyl-CoA carboxylase (ACC1), and liver X receptor-α (LXR-α) in HepG2 cells. Furthermore, we demonstrated that MECC down-regulated the PCSK9 gene expression through reducing the amount of nuclear hepatocyte nuclear factor-1α (HNF-1α), a major transcriptional regulator for activation of PCSK9 promoter, but not that of nuclear sterol-responsive element binding protein-2 (SREBP-2) in HepG2 cells. Finally, we identified the cajaninstilbene acid, a main bioactive stilbene component in MECC, which significantly modulated the LDLR and PCSK9 expression in HepG2 cells. Our current data suggest that the cajaninstilbene acid may contribute to the hypocholesterolemic activity of Cajanus cajan L. leaves. Our findings support that the extract of Cajanus cajan L. leaves may serve as a cholesterol-lowering agent.


Assuntos
Cajanus/química , Colesterol/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Extratos Vegetais/farmacologia , Pró-Proteína Convertase 9/genética , Receptores de LDL/genética , Biomarcadores , Genes Reporter , Células Hep G2 , Humanos , Lipogênese/efeitos dos fármacos , Folhas de Planta/química , Regiões Promotoras Genéticas , Pró-Proteína Convertase 9/metabolismo , RNA Mensageiro/genética , Receptores de LDL/metabolismo , Ativação Transcricional
16.
Int J Mol Sci ; 19(4)2018 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-29649138

RESUMO

Luteolin, a flavonoid nutraceutical abundant in vegetables and fruits, exhibits a wide range of bioactive properties, including antioxidant, anti-inflammatory and anti-cancer activities. Pituitary tumor-transforming gene 1 (PTTG1), an oncoprotein that regulates cell proliferation, is highly expressed in several types of cancer cells including leukemia. In this study, we aim to investigate the anti-cancer effects of luteolin on cells with differential PTTG1 expression and their underlying mechanisms in human myeloid leukemia cells. Methyl thiazolyl tetrazolium (MTT) assay data showed that luteolin (25-100 µM) significantly reduced cell viability in THP-1, HL-60 and K562 cells but did not affect normal peripheral blood mononuclear cells (PBMCs). Flow cytometric analysis and Western blot data demonstrated that luteolin induced a stronger apoptosis on undifferentiated myeloid leukemia cells with higher PTTG1 protein levels than on 12-myristate 13-acetate (PMA)- or all-trans-retinoic acid (ATRA)-differentiated cells with lower PTTG1 expression. Furthermore, PTTG1 knockdown by shRNA in leukemia cells suppressed cell proliferation, arrested cell-cycle progression and impaired the effectiveness of luteolin on cell-cycle regulation. Moreover, PTTG1-knockdown cells with luteolin exposure presented a reduction of the apoptotic proteins and maintained higher levels of the anti-apoptotic proteins such as Mcl-1, Bcl-2 and p21, which exhibited greater resistance to apoptosis. Finally, microarray analysis showed that 20 genes associated with cell proliferation, such as CXCL10, VEGFA, TNF, TP63 and FGFR1, were dramatically down-regulated in PTTG1-knockdown cells. Our current findings clearly demonstrate that luteolin-triggered leukemic cell apoptosis is modulated by the differential expression of the PTTG1. PTTG1 oncoprotein overexpression may modulate cell proliferation-related regulators and enhance the response of myeloid leukemia cells to luteolin. Luteolin is beneficial for the treatment of cancer cells with highly expressed PTTG1 oncoprotein.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Leucemia Mieloide/genética , Luteolina/farmacologia , Securina/genética , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Redes Reguladoras de Genes , Células HL-60 , Humanos , Células K562 , Leucemia Mieloide/tratamento farmacológico , Leucemia Mieloide/metabolismo , Securina/metabolismo , Células THP-1
17.
Biomed Chromatogr ; 30(9): 1449-57, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26873449

RESUMO

Cinnamon bark (Rou Gui in Chinese), cinnamon twig (Gui Zhi) and shaved cinnamon bark (Gui Sin) have been widely used as spices and in traditional Chinese medicine since ancient times. On-going issues related to quality and authenticity necessitate the development of analytical methods capable of providing an objective evaluation of samples. In this study, chemical fingerprints of cinnamon bark, cinnamon twigs and shaved cinnamon bark were established using liquid chromatography quadruple time-of-flight mass spectrometry in conjunction with principal component analysis (PCA). From 125 samples of cinnamon, we identified the following eight compounds and their the detection ratios: coumarin, cinnamaldehyde, cinnamyl alcohol, cinnamic acid, 2-hydroxycinnamaldehyde, 2-hydroxycinnamic acid, 2-methoxycinnamaldehyde and 4-methoxycinnamaldehyde. Of these, 4-methoxycinnamaldehyde presented the largest variations in detection ratio, making up 64.0, 97.4 and 50.0% in cinnamon bark, cinnamon twig, and shaved cinnamon bark, respectively. The quantities of cinnamyl alcohol, coumarin and cinnamaldehyde also varied between the three parts of the plant. Chemical fingerprints of the three cinnamon samples were established using principal component analysis, the results of which indicate that cinnamon bark and shaved cinnamon bark could be easily differentiated, despite a marked similarity in outward appearance. Cinnamon twig was also shown to depart from the other clusters. The proposed method provides a fast and efficient means of identifying cinnamon herbs for quality control purposes. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Cromatografia Líquida/métodos , Cinnamomum aromaticum , Espectrometria de Massas/métodos , Estruturas Vegetais , Padrões de Referência
18.
Tzu Chi Med J ; 36(4): 360-369, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39421488

RESUMO

A decrease in the levels of low-density lipoprotein receptors (LDLRs) leads to the accumulation of LDL cholesterol (LDL-C) in the bloodstream, resulting in hypercholesterolemia and atherosclerotic cardiovascular diseases. Increasing the expression level or inducing the activity of LDLR in hepatocytes can effectively control hypercholesterolemia. Proprotein convertase subtilisin/kexin type 9 (PCSK9) protein, primarily produced in the liver, promotes the degradation of LDLR. Inhibiting the expression and/or function of PCSK9 can increase the levels of LDLR on the surface of hepatocytes and promote LDL-C clearance from the plasma. Thus, targeting PCSK9 represents a new strategy for developing preventive and therapeutic interventions for hypercholesterolemia. Currently, monoclonal antibodies are used as PCSK9 inhibitors in clinical practice. However, the need for oral and affordable anti-PCSK9 medications limits the perspective of choosing PCSK9 inhibitors for clinical usage. Emerging research reports have demonstrated that natural phytochemicals have efficacy in maintaining cholesterol stability and regulating lipid metabolism. Developing novel natural phytochemical PCSK9 inhibitors can serve as a starting point for developing small-molecule drugs to reduce plasma LDL-C levels in patients. In this review, we summarize the current literature on the critical role of PCSK9 in controlling LDLR degradation and hypercholesterolemia, and we discuss the results of studies attempting to develop PCSK9 inhibitors, with an emphasis on the inhibitory effects of natural phytochemicals on PCSK9. Furthermore, we provide insight into the mechanisms of action by which the reported phytochemicals exert their potential PCSK9 inhibitory effects against hypercholesterolemia.

19.
J Health Psychol ; 29(9): 921-934, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38196159

RESUMO

This study aims to examine changes in body image (BI) over time and factors related to BI among patients with prostate cancer who receive hormone therapy (HT). A cross-sectional design and longitudinal design were utilized. Patients with prostate cancer who received HT were recruited from the urology outpatient departments in two hospitals in Taiwan between August 2017 and December 2020. Cross-sectional data were collected from 177 patients who had started HT for prostate cancer. Longitudinal data were collected from 34 newly diagnosed patients before receiving HT and at 1, 3, 6, and 12 months after HT. The variables measured included hormonal symptoms and distress, self-efficacy, and BI. The results showed that BI dissatisfaction ranged from 6.1% to 17.2%. Hormonal symptoms and distress (e.g. lack of vitality) were correlated with BI dissatisfaction. Education on the side effects of HT and coping strategies can be provided to patients to prevent BI dissatisfaction.


Assuntos
Imagem Corporal , Neoplasias da Próstata , Humanos , Masculino , Neoplasias da Próstata/psicologia , Neoplasias da Próstata/tratamento farmacológico , Estudos Transversais , Estudos Longitudinais , Idoso , Imagem Corporal/psicologia , Pessoa de Meia-Idade , Taiwan , Antineoplásicos Hormonais/uso terapêutico
20.
Biomed Pharmacother ; 174: 116598, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38615609

RESUMO

Angiopoietin-like 3 (ANGPTL3) acts as an inhibitor of lipoprotein lipase (LPL), impeding the breakdown of triglyceride-rich lipoproteins (TGRLs) in circulation. Targeting ANGPTL3 is considered a novel strategy for improving dyslipidemia and atherosclerotic cardiovascular diseases (ASCVD). Hops (Humulus lupulus L.) contain several bioactive prenylflavonoids, including xanthohumol (Xan), isoxanthohumol (Isoxan), 6-prenylnaringenin (6-PN), and 8-prenylnaringenin (8-PN), with the potential to manage lipid metabolism. The aim of this study was to investigate the lipid-lowering effects of Xan, the effective prenylated chalcone in attenuating ANGPTL3 transcriptional activity, both in vitro using hepatic cells and in vivo using zebrafish models, along with exploring the underlying mechanisms. Xan (10 and 20 µM) significantly reduced ANGPTL3 mRNA and protein expression in HepG2 and Huh7 cells, leading to a marked decrease in secreted ANGPTL3 proteins via hepatic cells. In animal studies, orally administered Xan significantly alleviated plasma triglyceride (TG) and cholesterol levels in zebrafish fed a high-fat diet. Furthermore, it reduced hepatic ANGPTL3 protein levels and increased LPL activity in zebrafish models, indicating its potential to modulate lipid profiles in circulation. Furthermore, molecular docking results predicted that Xan exhibits a higher binding affinity to interact with liver X receptor α (LXRα) and retinoic acid X receptor (RXR) than their respective agonists, T0901317 and 9-Cis-retinoic acid (9-Cis-RA). We observed that Xan suppressed hepatic ANGPTL3 expression by antagonizing the LXRα/RXR-mediated transcription. These findings suggest that Xan ameliorates dyslipidemia by modulating the LXRα/RXR-ANGPTL3-LPL axis. Xan represents a novel potential inhibitor of ANGPTL3 for the prevention or treatment of ASCVD.


Assuntos
Proteína 3 Semelhante a Angiopoietina , Dieta Hiperlipídica , Flavonoides , Metabolismo dos Lipídeos , Lipase Lipoproteica , Receptores X do Fígado , Propiofenonas , Peixe-Zebra , Animais , Receptores X do Fígado/metabolismo , Propiofenonas/farmacologia , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Flavonoides/farmacologia , Lipase Lipoproteica/metabolismo , Receptores X de Retinoides/metabolismo , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Chalconas/farmacologia , Fígado/efeitos dos fármacos , Fígado/metabolismo
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