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1.
Cell ; 183(3): 802-817.e24, 2020 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-33053319

RESUMO

Mammalian SWI/SNF complexes are ATP-dependent chromatin remodeling complexes that regulate genomic architecture. Here, we present a structural model of the endogenously purified human canonical BAF complex bound to the nucleosome, generated using cryoelectron microscopy (cryo-EM), cross-linking mass spectrometry, and homology modeling. BAF complexes bilaterally engage the nucleosome H2A/H2B acidic patch regions through the SMARCB1 C-terminal α-helix and the SMARCA4/2 C-terminal SnAc/post-SnAc regions, with disease-associated mutations in either causing attenuated chromatin remodeling activities. Further, we define changes in BAF complex architecture upon nucleosome engagement and compare the structural model of endogenous BAF to those of related SWI/SNF-family complexes. Finally, we assign and experimentally interrogate cancer-associated hot-spot mutations localizing within the endogenous human BAF complex, identifying those that disrupt BAF subunit-subunit and subunit-nucleosome interfaces in the nucleosome-bound conformation. Taken together, this integrative structural approach provides important biophysical foundations for understanding the mechanisms of BAF complex function in normal and disease states.


Assuntos
Doença , Modelos Moleculares , Complexos Multiproteicos/química , Complexos Multiproteicos/metabolismo , Montagem e Desmontagem da Cromatina , Microscopia Crioeletrônica , DNA Helicases/química , DNA Helicases/genética , DNA Helicases/metabolismo , Doença/genética , Humanos , Mutação de Sentido Incorreto/genética , Proteínas Nucleares/química , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Nucleossomos/metabolismo , Ligação Proteica , Domínios Proteicos , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Saccharomyces cerevisiae/metabolismo , Homologia Estrutural de Proteína , Fatores de Transcrição/química , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
2.
Nat Immunol ; 23(9): 1330-1341, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35999392

RESUMO

Fibroblasts, the most abundant structural cells, exert homeostatic functions but also drive disease pathogenesis. Single-cell technologies have illuminated the shared characteristics of pathogenic fibroblasts in multiple diseases including autoimmune arthritis, cancer and inflammatory colitis. However, the molecular mechanisms underlying the disease-associated fibroblast phenotypes remain largely unclear. Here, we identify ETS1 as the key transcription factor governing the pathological tissue-remodeling programs in fibroblasts. In arthritis, ETS1 drives polarization toward tissue-destructive fibroblasts by orchestrating hitherto undescribed regulatory elements of the osteoclast differentiation factor receptor activator of nuclear factor-κB ligand (RANKL) as well as matrix metalloproteinases. Fibroblast-specific ETS1 deletion resulted in ameliorated bone and cartilage damage under arthritic conditions without affecting the inflammation level. Cross-tissue fibroblast single-cell data analyses and genetic loss-of-function experiments lent support to the notion that ETS1 defines the perturbation-specific fibroblasts shared among various disease settings. These findings provide a mechanistic basis for pathogenic fibroblast polarization and have important therapeutic implications.


Assuntos
Artrite Reumatoide , Fibroblastos , Proteína Proto-Oncogênica c-ets-1 , Artrite Reumatoide/metabolismo , Artrite Reumatoide/patologia , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Metaloproteinases da Matriz/metabolismo , Proteína Proto-Oncogênica c-ets-1/genética , Proteína Proto-Oncogênica c-ets-1/metabolismo , Ligante RANK/genética , Fatores de Transcrição/metabolismo
3.
Cell ; 175(3): 822-834.e18, 2018 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-30318141

RESUMO

Mdn1 is an essential AAA (ATPase associated with various activities) protein that removes assembly factors from distinct precursors of the ribosomal 60S subunit. However, Mdn1's large size (∼5,000 amino acid [aa]) and its limited homology to other well-studied proteins have restricted our understanding of its remodeling function. Here, we present structures for S. pombe Mdn1 in the presence of AMPPNP at up to ∼4 Å or ATP plus Rbin-1, a chemical inhibitor, at ∼8 Å resolution. These data reveal that Mdn1's MIDAS domain is tethered to its ring-shaped AAA domain through an ∼20 nm long structured linker and a flexible ∼500 aa Asp/Glu-rich motif. We find that the MIDAS domain, which also binds other ribosome-assembly factors, docks onto the AAA ring in a nucleotide state-specific manner. Together, our findings reveal how conformational changes in the AAA ring can be directly transmitted to the MIDAS domain and thereby drive the targeted release of assembly factors from ribosomal 60S-subunit precursors.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/química , Simulação de Dinâmica Molecular , Proteínas de Schizosaccharomyces pombe/química , Schizosaccharomyces/enzimologia , Motivos de Aminoácidos , Animais , Sítios de Ligação , Microscopia Crioeletrônica , Biogênese de Organelas , Ligação Proteica , Subunidades Ribossômicas Maiores de Eucariotos/metabolismo , Células Sf9 , Spodoptera
4.
Nat Immunol ; 21(8): 892-901, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32601470

RESUMO

Autoreactive T cells are eliminated in the thymus to prevent autoimmunity by promiscuous expression of tissue-restricted self-antigens in medullary thymic epithelial cells. This expression is dependent on the transcription factor Fezf2, as well as the transcriptional regulator Aire, but the entire picture of the transcriptional program has been obscure. Here, we found that the chromatin remodeler Chd4, also called Mi-2ß, plays a key role in the self-antigen expression in medullary thymic epithelial cells. To maximize the diversity of self-antigen expression, Fezf2 and Aire utilized completely distinct transcriptional mechanisms, both of which were under the control of Chd4. Chd4 organized the promoter regions of Fezf2-dependent genes, while contributing to the Aire-mediated induction of self-antigens via super-enhancers. Mice deficient in Chd4 specifically in thymic epithelial cells exhibited autoimmune phenotypes, including T cell infiltration. Thus, Chd4 plays a critical role in integrating Fezf2- and Aire-mediated gene induction to establish central immune tolerance.


Assuntos
Autoantígenos/imunologia , Tolerância Central/fisiologia , Regulação da Expressão Gênica/imunologia , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/imunologia , Animais , Autoantígenos/biossíntese , DNA Helicases/imunologia , DNA Helicases/metabolismo , Células HEK293 , Humanos , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fatores de Transcrição/imunologia , Fatores de Transcrição/metabolismo , Proteína AIRE
5.
Cell ; 168(6): 1000-1014.e15, 2017 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-28283057

RESUMO

Super-enhancers are an emerging subclass of regulatory regions controlling cell identity and disease genes. However, their biological function and impact on miRNA networks are unclear. Here, we report that super-enhancers drive the biogenesis of master miRNAs crucial for cell identity by enhancing both transcription and Drosha/DGCR8-mediated primary miRNA (pri-miRNA) processing. Super-enhancers, together with broad H3K4me3 domains, shape a tissue-specific and evolutionarily conserved atlas of miRNA expression and function. CRISPR/Cas9 genomics revealed that super-enhancer constituents act cooperatively and facilitate Drosha/DGCR8 recruitment and pri-miRNA processing to boost cell-specific miRNA production. The BET-bromodomain inhibitor JQ1 preferentially inhibits super-enhancer-directed cotranscriptional pri-miRNA processing. Furthermore, super-enhancers are characterized by pervasive interaction with DGCR8/Drosha and DGCR8/Drosha-regulated mRNA stability control, suggesting unique RNA regulation at super-enhancers. Finally, super-enhancers mark multiple miRNAs associated with cancer hallmarks. This study presents principles underlying miRNA biology in health and disease and an unrecognized higher-order property of super-enhancers in RNA processing beyond transcription.


Assuntos
Elementos Facilitadores Genéticos , MicroRNAs/metabolismo , Animais , Azepinas/farmacologia , Regulação da Expressão Gênica , Código das Histonas , Humanos , Camundongos , Neoplasias/genética , Especificidade de Órgãos , Processamento Pós-Transcricional do RNA/efeitos dos fármacos , Fatores de Transcrição/metabolismo , Transcrição Gênica , Triazóis/farmacologia
6.
Cell ; 171(5): 1138-1150.e15, 2017 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-29056342

RESUMO

Despite its success in several clinical trials, cancer immunotherapy remains limited by the rarity of targetable tumor-specific antigens, tumor-mediated immune suppression, and toxicity triggered by systemic delivery of potent immunomodulators. Here, we present a proof-of-concept immunomodulatory gene circuit platform that enables tumor-specific expression of immunostimulators, which could potentially overcome these limitations. Our design comprised de novo synthetic cancer-specific promoters and, to enhance specificity, an RNA-based AND gate that generates combinatorial immunomodulatory outputs only when both promoters are mutually active. These outputs included an immunogenic cell-surface protein, a cytokine, a chemokine, and a checkpoint inhibitor antibody. The circuits triggered selective T cell-mediated killing of cancer cells, but not of normal cells, in vitro. In in vivo efficacy assays, lentiviral circuit delivery mediated significant tumor reduction and prolonged mouse survival. Our design could be adapted to drive additional immunomodulators, sense other cancers, and potentially treat other diseases that require precise immunological programming.


Assuntos
Redes Reguladoras de Genes , Imunoterapia/métodos , Neoplasias Ovarianas/terapia , Animais , Feminino , Humanos , Imunomodulação , Camundongos , Neoplasias Ovarianas/imunologia , Regiões Promotoras Genéticas , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T Citotóxicos/imunologia
7.
Mol Cell ; 69(4): 648-663.e7, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29398447

RESUMO

Regulation of RNA polymerase II (Pol II) elongation is a critical step in gene regulation. Here, we report that U1 snRNP recognition and transcription pausing at stable nucleosomes are linked through premature polyadenylation signal (PAS) termination. By generating RNA exosome conditional deletion mouse embryonic stem cells, we identified a large class of polyadenylated short transcripts in the sense direction destabilized by the RNA exosome. These PAS termination events are enriched at the first few stable nucleosomes flanking CpG islands and suppressed by U1 snRNP. Thus, promoter-proximal Pol II pausing consists of two processes: TSS-proximal and +1 stable nucleosome pausing, with PAS termination coinciding with the latter. While pausing factors NELF/DSIF only function in the former step, flavopiridol-sensitive mechanism(s) and Myc modulate both steps. We propose that premature PAS termination near the nucleosome-associated pause site represents a common transcriptional elongation checkpoint regulated by U1 snRNP recognition, nucleosome stability, and Myc activity.


Assuntos
Regulação da Expressão Gênica , Nucleossomos/fisiologia , Poliadenilação , RNA Polimerase II/metabolismo , Ribonucleoproteína Nuclear Pequena U1/metabolismo , Spliceossomos/metabolismo , Elongação da Transcrição Genética , Animais , Células Cultivadas , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Complexo Multienzimático de Ribonucleases do Exossomo/genética , Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo , Células HEK293 , Humanos , Camundongos , Regiões Promotoras Genéticas , RNA Polimerase II/genética , Ribonucleoproteína Nuclear Pequena U1/genética , Spliceossomos/genética , Fatores de Transcrição
8.
Circulation ; 149(8): 585-600, 2024 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-37994553

RESUMO

BACKGROUND: Bleeding rates on dual antiplatelet therapy (DAPT) within 1 month after percutaneous coronary intervention (PCI) remain high in clinical practice, particularly in patients with acute coronary syndrome or high bleeding risk. Aspirin-free strategy might result in lower bleeding early after PCI without increasing cardiovascular events, but its efficacy and safety have not yet been proven in randomized trials. METHODS: We randomly assigned 6002 patients with acute coronary syndrome or high bleeding risk just before PCI either to prasugrel (3.75 mg/day) monotherapy or to DAPT with aspirin (81-100 mg/day) and prasugrel (3.75 mg/day) after loading of 20 mg of prasugrel in both groups. The coprimary end points were major bleeding (Bleeding Academic Research Consortium 3 or 5) for superiority and cardiovascular events (a composite of cardiovascular death, myocardial infarction, definite stent thrombosis, or ischemic stroke) for noninferiority with a relative 50% margin. RESULTS: The full analysis set population consisted of 5966 patients (no-aspirin group, 2984 patients; DAPT group, 2982 patients; age, 71.6±11.7 years; men, 76.6%; acute coronary syndrome, 75.0%). Within 7 days before randomization, aspirin alone, aspirin with P2Y12 inhibitor, oral anticoagulants, and intravenous heparin infusion were given in 21.3%, 6.4%, 8.9%, and 24.5%, respectively. Adherence to the protocol-specified antiplatelet therapy was 88% in both groups at 1 month. At 1 month, the no-aspirin group was not superior to the DAPT group for the coprimary bleeding end point (4.47% and 4.71%; hazard ratio, 0.95 [95% CI, 0.75-1.20]; Psuperiority=0.66). The no-aspirin group was noninferior to the DAPT group for the coprimary cardiovascular end point (4.12% and 3.69%; hazard ratio, 1.12 [95% CI, 0.87-1.45]; Pnoninferiority=0.01). There was no difference in net adverse clinical outcomes and each component of coprimary cardiovascular end point. There was an excess of any unplanned coronary revascularization (1.05% and 0.57%; hazard ratio, 1.83 [95%CI, 1.01-3.30]) and subacute definite or probable stent thrombosis (0.58% and 0.17%; hazard ratio, 3.40 [95% CI, 1.26-9.23]) in the no-aspirin group compared with the DAPT group. CONCLUSIONS: The aspirin-free strategy using low-dose prasugrel compared with the DAPT strategy failed to attest superiority for major bleeding within 1 month after PCI but was noninferior for cardiovascular events within 1 month after PCI. However, the aspirin-free strategy was associated with a signal suggesting an excess of coronary events. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04609111.


Assuntos
Síndrome Coronariana Aguda , Aspirina/análogos & derivados , Nitratos , Intervenção Coronária Percutânea , Trombose , Masculino , Humanos , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Inibidores da Agregação Plaquetária/efeitos adversos , Cloridrato de Prasugrel/efeitos adversos , Síndrome Coronariana Aguda/tratamento farmacológico , Intervenção Coronária Percutânea/efeitos adversos , Quimioterapia Combinada , Aspirina/efeitos adversos , Hemorragia/etiologia , Stents , Trombose/epidemiologia , Trombose/etiologia , Trombose/prevenção & controle , Resultado do Tratamento
9.
J Biol Chem ; 299(8): 104976, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37390985

RESUMO

Urate transporters play a pivotal role in urate handling in the human body, but the urate transporters identified to date do not account for all known molecular processes of urate handling, suggesting the presence of latent machineries. We recently showed that a urate transporter SLC2A12 is also a physiologically important exporter of ascorbate (the main form of vitamin C in the body) that would cooperate with an ascorbate importer, sodium-dependent vitamin C transporter 2 (SVCT2). Based on the dual functions of SLC2A12 and cooperativity between SLC2A12 and SVCT2, we hypothesized that SVCT2 might be able to transport urate. To test this proposal, we conducted cell-based analyses using SVCT2-expressing mammalian cells. The results demonstrated that SVCT2 is a novel urate transporter. Vitamin C inhibited SVCT2-mediated urate transport with a half-maximal inhibitory concentration of 36.59 µM, suggesting that the urate transport activity may be sensitive to physiological ascorbate levels in blood. Similar results were obtained for mouse Svct2. Further, using SVCT2 as a sodium-dependent urate importer, we established a cell-based urate efflux assay that will be useful for identification of other novel urate exporters as well as functional characterization of nonsynonymous variants of already-identified urate exporters including ATP-binding cassette transporter G2. While more studies will be needed to elucidate the physiological impact of SVCT2-mediated urate transport, our findings deepen understanding of urate transport machineries.


Assuntos
Transportadores de Ânions Orgânicos Dependentes de Sódio , Transportadores de Sódio Acoplados à Vitamina C , Ácido Úrico , Animais , Humanos , Camundongos , Ácido Ascórbico/metabolismo , Transportadores de Ânions Orgânicos Dependentes de Sódio/genética , Transportadores de Ânions Orgânicos Dependentes de Sódio/metabolismo , Transportadores de Sódio Acoplados à Vitamina C/genética , Ácido Úrico/metabolismo
10.
Nature ; 556(7700): 214-218, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29618813

RESUMO

The gastric proton pump-the H+, K+-ATPase-is a P-type ATPase responsible for acidifying the gastric juice down to pH 1. This corresponds to a million-fold proton gradient across the membrane of the parietal cell, the steepest known cation gradient of any mammalian tissue. The H+, K+-ATPase is an important target for drugs that treat gastric acid-related diseases. Here we present crystal structures of the H+, K+-ATPase in complex with two blockers, vonoprazan and SCH28080, in the luminal-open state, at 2.8 Å resolution. The drugs have partially overlapping but clearly distinct binding modes in the middle of a conduit running from the gastric lumen to the cation-binding site. The crystal structures suggest that the tight configuration at the cation-binding site lowers the pK a value of Glu820 sufficiently to enable the release of a proton even into the pH 1 environment of the stomach.


Assuntos
ATPase Trocadora de Hidrogênio-Potássio/química , Estômago/enzimologia , Sequência de Aminoácidos , Animais , Sítios de Ligação , Cátions Monovalentes/metabolismo , Cristalografia por Raios X , Células HEK293 , Humanos , Concentração de Íons de Hidrogênio , Imidazóis/química , Imidazóis/farmacologia , Modelos Moleculares , Potássio/metabolismo , Ligação Proteica , Inibidores da Bomba de Prótons/química , Inibidores da Bomba de Prótons/farmacologia , Prótons , Pirróis/química , Pirróis/farmacologia , Coelhos , Sulfonamidas/química , Sulfonamidas/farmacologia , Suínos
11.
Nature ; 561(7722): 195-200, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30185903

RESUMO

Receptor activator of nuclear factor-kappa B (RANK) ligand (RANKL) binds RANK on the surface of osteoclast precursors to trigger osteoclastogenesis. Recent studies have indicated that osteocytic RANKL has an important role in osteoclastogenesis during bone remodelling; however, the role of osteoblastic RANKL remains unclear. Here we show that vesicular RANK, which is secreted from the maturing osteoclasts, binds osteoblastic RANKL and promotes bone formation by triggering RANKL reverse signalling, which activates Runt-related transcription factor 2 (Runx2). The proline-rich motif in the RANKL cytoplasmic tail is required for reverse signalling, and a RANKL(Pro29Ala) point mutation reduces activation of the reverse signalling pathway. The coupling of bone resorption and formation is disrupted in RANKL(Pro29Ala) mutant mice, indicating that osteoblastic RANKL functions as a coupling signal acceptor that recognizes vesicular RANK. RANKL reverse signalling is therefore a potential pharmacological target for avoiding the reduced bone formation associated with inhibition of osteoclastogenesis.


Assuntos
Reabsorção Óssea/metabolismo , Osteogênese , Ligante RANK/metabolismo , Transdução de Sinais , Substituição de Aminoácidos , Animais , Diferenciação Celular , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Reagentes de Ligações Cruzadas/química , Vesículas Citoplasmáticas/metabolismo , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Osteoblastos/citologia , Osteoblastos/metabolismo , Osteoclastos/citologia , Osteoclastos/metabolismo , Ligante RANK/química , Ligante RANK/deficiência , Ligante RANK/genética , Receptor Ativador de Fator Nuclear kappa-B/genética , Receptor Ativador de Fator Nuclear kappa-B/metabolismo
12.
Int J Clin Pharmacol Ther ; 62(7): 307-310, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38726563

RESUMO

OBJECTIVE: Infliximab is indicated for a wide range of diseases, and infusion reactions (IRs) have been reported after infliximab administration in 17.6% of patients in clinical practice. This study aimed to identify the risk factors for IRs before the administration of infliximab based on available patient information. MATERIALS AND METHODS: We retrospectively analyzed patients treated with infliximab. Data were compared between patients with and without IRs immediately before initiation of infliximab. RESULTS: Elevated C-reactive protein (CRP) (odds ratio (OR), 2.150; 95% confidence interval (CI), 1.329 - 3.477; p = 0.002) before infliximab administration was a significant risk factor for developing an IR. CONCLUSION: Patients with elevated CRP levels before therapy initiation may require more careful monitoring after infliximab administration.


Assuntos
Proteína C-Reativa , Infliximab , Humanos , Infliximab/efeitos adversos , Infliximab/administração & dosagem , Estudos Retrospectivos , Fatores de Risco , Feminino , Masculino , Pessoa de Meia-Idade , Infusões Intravenosas , Adulto , Proteína C-Reativa/análise , Idoso , Razão de Chances
13.
J Struct Biol ; 215(3): 107984, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37315821

RESUMO

Water channels, which are small membrane proteins almost entirely buried in lipid membranes, are challenging research targets for single-particle cryo-electron microscopy (cryo-EM), a powerful technique routinely used to determine the structures of membrane proteins. Because the single-particle method enables structural analysis of a whole protein with flexible parts that interfere with crystallization, we have focused our efforts on analyzing water channel structures. Here, utilizing this system, we analyzed the structure of full-length aquaporin-2 (AQP2), a primary regulator of vasopressin-dependent reabsorption of water at the renal collecting ducts. The 2.9 Å resolution map revealed a cytoplasmic extension of the cryo-EM density that was presumed to be the highly flexible C-terminus at which the localization of AQP2 is regulated in the renal collecting duct cells. We also observed a continuous density along the common water pathway inside the channel pore and lipid-like molecules at the membrane interface. Observations of these constructions in the AQP2 structure analyzed without any fiducial markers (e.g., a rigidly bound antibody) indicate that single-particle cryo-EM will be useful for investigating water channels in native states as well as in complexes with chemical compounds.


Assuntos
Aquaporina 2 , Proteínas de Membrana , Aquaporina 2/metabolismo , Microscopia Crioeletrônica/métodos , Proteínas de Membrana/química , Água , Lipídeos
14.
Pflugers Arch ; 475(4): 489-504, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36749388

RESUMO

Uric acid, the end product of purine metabolism in humans, is crucial because of its anti-oxidant activity and a causal relationship with hyperuricemia and gout. Several physiologically important urate transporters regulate this water-soluble metabolite in the human body; however, the existence of latent transporters has been suggested in the literature. We focused on the Escherichia coli urate transporter YgfU, a nucleobase-ascorbate transporter (NAT) family member, to address this issue. Only SLC23A proteins are members of the NAT family in humans. Based on the amino acid sequence similarity to YgfU, we hypothesized that SLC23A1, also known as sodium-dependent vitamin C transporter 1 (SVCT1), might be a urate transporter. First, we identified human SVCT1 and mouse Svct1 as sodium-dependent low-affinity/high-capacity urate transporters using mammalian cell-based transport assays. Next, using the CRISPR-Cas9 system followed by the crossing of mice, we generated Svct1 knockout mice lacking both urate transporter 1 and uricase. In the hyperuricemic mice model, serum urate levels were lower than controls, suggesting that Svct1 disruption could reduce serum urate. Given that Svct1 physiologically functions as a renal vitamin C re-absorber, it could also be involved in urate re-uptake from urine, though additional studies are required to obtain deeper insights into the underlying mechanisms. Our findings regarding the dual-substrate specificity of SVCT1 expand the understanding of urate handling systems and functional evolutionary changes in NAT family proteins.


Assuntos
Transportadores de Ânions Orgânicos , Ácido Úrico , Animais , Humanos , Camundongos , Sequência de Aminoácidos , Ácido Ascórbico/metabolismo , Transporte Biológico , Mamíferos/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Transportadores de Sódio Acoplados à Vitamina C/genética , Transportadores de Sódio Acoplados à Vitamina C/metabolismo , Ácido Úrico/metabolismo
15.
BMC Cancer ; 23(1): 979, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37833660

RESUMO

BACKGROUND: Weekly paclitaxel + ramucirumab (wPTX + RAM) therapy is recommended as the standard second-line chemotherapy regimen for unresectable advanced/recurrent gastric cancer (GC) or esophagogastric junction cancer. Recent subgroup analysis of the RAINBOW trial revealed a higher frequency of severe neutropenia due to wPTX + RAM in Japanese compared to Western patients. However, no risk factors for severe neutropenia have been identified. METHODS: This retrospective observational study included patients with advanced/unresectable gastric or esophagogastric junction cancer who received wPTX + RAM after failure to respond to platinum and fluoropyrimidine doublet chemotherapy between June 2015 and April 2020. We conducted multivariable logistic regression analyses to identify the risk factors associated with grade 4 neutropenia and febrile neutropenia (FN). In addition, we investigated the relationship between the number of risk factors and overall survival (OS) and progression-free survival (PFS). RESULTS: Among 66 patients who met the inclusion criteria, grade 4 neutropenia and FN occurred in 21 (31.8%) and 12 (18.2%) patients, respectively. Prior treatment with oxaliplatin-containing regimens was identified as an independent risk factor for developing grade 4 neutropenia (odds ratio (OR) 20.034, 95% confidence interval (95% CI) 3.216-124.807, P = 0.001). Total bilirubin of > 1.5 mg/dL (OR 31.316, 95% CI 2.052-477.843, P = 0.013) and prior treatment with oxaliplatin-containing regimen (OR 12.502, 95% CI 1.141-137.022, P = 0.039) were identified as independent risk factors for developing FN. Next, we classified patients with 0, 1, 2 risk factor(s) as RF-0, RF-1, and RF-2 subgroups, respectively, and compared the PFS and OS among the three subgroups. PFS was not significantly different among the three subgroups, whereas OS was significantly shorter in the RF-2 subgroup (median 1.4 month, 95% CI 0.0-5.3 month) than in the RF-0 subgroup (median 10.2 month, 95% CI 6.8-13.5 month, P < 0.01 vs RF-2) and RF-1 subgroup (median 13.3 month, 95% CI 10.9-15.7 month, P < 0.01 vs RF-2). CONCLUSIONS: Careful monitoring for grade 4 neutropenia and FN is needed for patients receiving wPTX + RAM therapy who have a history of treatment with oxaliplatin-containing regimens and higher total bilirubin levels.


Assuntos
Neutropenia Febril , Neoplasias Gástricas , Humanos , Paclitaxel , Oxaliplatina/efeitos adversos , Estudos Retrospectivos , Recidiva Local de Neoplasia/tratamento farmacológico , Junção Esofagogástrica , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bilirrubina , Neutropenia Febril/induzido quimicamente , Neutropenia Febril/epidemiologia , Ramucirumab
16.
PLoS Comput Biol ; 18(9): e1010441, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36084151

RESUMO

Simulating complex biological models consisting of multiple ordinary differential equations can aid in the prediction of the pharmacological/biological responses; however, they are often hampered by the availability of reliable kinetic parameters. In the present study, we aimed to discover the properties of behaviors without determining an optimal combination of kinetic parameter values (parameter set). The key idea was to collect as many parameter sets as possible. Given that many systems are biologically stable and resilient (BSR), we focused on the dynamics around the steady state and formulated objective functions for BSR by partial linear approximation of the focused region. Using the objective functions and modified global cluster Newton method, we developed an algorithm for a thorough exploration of the allowable parameter space for biological systems (TEAPS). We first applied TEAPS to the NF-κB signaling model. This system shows a damped oscillation after stimulation and seems to fit the BSR constraint. By applying TEAPS, we found several directions in parameter space which stringently determines the BSR property. In such directions, the experimentally fitted parameter values were included in the range of the obtained parameter sets. The arachidonic acid metabolic pathway model was used as a model related to pharmacological responses. The pharmacological effects of nonsteroidal anti-inflammatory drugs were simulated using the parameter sets obtained by TEAPS. The structural properties of the system were partly extracted by analyzing the distribution of the obtained parameter sets. In addition, the simulations showed inter-drug differences in prostacyclin to thromboxane A2 ratio such that aspirin treatment tends to increase the ratio, while rofecoxib treatment tends to decrease it. These trends are comparable to the clinical observations. These results on real biological models suggest that the parameter sets satisfying the BSR condition can help in finding biologically plausible parameter sets and understanding the properties of biological systems.


Assuntos
NF-kappa B , Tromboxano A2 , Algoritmos , Anti-Inflamatórios , Ácido Araquidônico , Aspirina/farmacologia , Modelos Biológicos , Prostaglandinas I
17.
J Endovasc Ther ; 30(2): 223-231, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35179063

RESUMO

BACKGROUND: Despite the increase in the number of patients with peripheral artery disease (PAD), the pathophysiology is not fully elucidated. Recently, angioscopy with a 0.48-megapixel equivalent resolution camera became available for patients with PAD. We aimed to compare the plaque component between native stenosis and occlusion in the femoropopliteal artery using this modality. MATERIALS AND METHODS: Thirty-two consecutive patients who underwent endovascular treatment for native femoropopliteal artery disease with angioscopy were studied. The major angioscopic classifications of each lesion were defined as follows: atheromatous plaque (AP) was defined as luminal narrowing without any protrusion, calcified nodule (CN) was defined as a protruding bump with surface irregularity, a mainly reddish thrombus was defined as organizing thrombus (OG), and organized thrombus (OD) was defined by more than half of the thrombus showing a whitish intima-like appearance. RESULTS: A total of 34 lesions (stenosis, n=18; occlusion, n=16) from 32 patients were included. All stenotic lesions showed AP or CN (n=8 [44%], n=10 [56%], respectively), whereas all occluded lesions showed OG or OD (n=5 [31%], n=11 [69%], respectively), which amounted to a statistically significant difference (p<0.001). In occluded lesions, stiff wires (>3 g) were required to cross all lesions classified as OD, whereas this was not always necessary for lesions classified as OG (11 [100%] of 11, 1 [25%] of 5, respectively; p=0.04). Yellow color plaques were observed to a similar degree in all angioscopic classifications. Major adverse limb events, defined as amputation and any reintervention at 12 months, were highly variable, depending on the angioscopic findings, and tended to be more frequently observed in CN and OD (13% in AP, 40% in CN, 0% in OT, and 36% in OD, p=0.25). CONCLUSION: Angioscopy revealed varying components in stenosis and occlusion with different degrees of clinical impact. This may provide new information on the pathophysiology of PAD.


Assuntos
Doença Arterial Periférica , Placa Aterosclerótica , Trombose , Humanos , Angioscopia , Constrição Patológica , Resultado do Tratamento , Artéria Femoral/diagnóstico por imagem , Artéria Femoral/patologia , Trombose/patologia , Placa Aterosclerótica/patologia , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/terapia , Doença Arterial Periférica/patologia , Vasos Coronários/patologia
18.
Circ J ; 87(5): 657-668, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-36477579

RESUMO

BACKGROUND: The REAL-CAD trial, reported in 2017, demonstrated a significant reduction in cardiovascular events with high-intensity statins in patients with chronic coronary syndrome. However, data are scarce on the use of high-intensity statins in Japanese patients with acute coronary syndrome (ACS).Methods and Results: In STOPDAPT-2 ACS, which exclusively enrolled ACS patients between March 2018 and June 2020, 1,321 (44.2%) patients received high-intensity statins at discharge, whereas of the remaining 1,667 patients, 96.0% were treated with low-dose statins. High-intensity statins were defined as the maximum approved doses of strong statins in Japan. The incidence of the cardiovascular composite endpoint (cardiovascular death, myocardial infarction, definite stent thrombosis, stroke) was significantly lower in patients with than without high-intensity statins (1.44% vs. 2.69% [log-rank P=0.025]; adjusted hazard ratio [aHR] 0.48, 95% confidence interval [CI] 0.24-0.94, P=0.03) and the effect was evident beyond 60 days after the index percutaneous coronary intervention (log-rank P=0.01; aHR 0.38, 95% CI 0.17-0.86, P=0.02). As for the bleeding endpoint, there was no significant difference between the 2 groups (0.99% vs. 0.73% [log-rank P=0.43]; aHR 0.96, 95% CI 0.35-2.60, P=0.93). CONCLUSIONS: The prevalence of high-intensity statins has increased substantially in Japan. The use of the higher doses of statins in ACS patients recommended in the guidelines was associated with a significantly lower risk of the primary cardiovascular composite endpoint compared with lower-dose statins.


Assuntos
Síndrome Coronariana Aguda , Inibidores de Hidroximetilglutaril-CoA Redutases , Infarto do Miocárdio , Intervenção Coronária Percutânea , Humanos , Síndrome Coronariana Aguda/terapia , População do Leste Asiático , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Infarto do Miocárdio/etiologia , Intervenção Coronária Percutânea/efeitos adversos , Prevalência , Resultado do Tratamento
19.
Support Care Cancer ; 31(2): 150, 2023 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-36737558

RESUMO

PURPOSE: Docetaxel + cisplatin + 5-fluorouracil (DCF) therapy, a frequently prescribed regimen for esophageal cancer, is associated with a high risk of febrile neutropenia (FN). This study investigated whether a low skeletal muscle mass index (SMI) is an independent risk factor for FN. METHODS: This retrospective, observational study investigated the SMI of patients with esophageal cancer who received DCF therapy between March 2018 and July 2020. Based on the Asian sarcopenia criteria, patients were divided into two groups: high and low SMI (SMI of < 7.0 and 5.7 kg/m2 for males and females, respectively). The incidence of FN was then compared between the two groups. RESULTS: Thirty-nine patients (20 and 19 in the high- and low-SMI groups, respectively) were included in this study. The incidence of FN was significantly higher in the low-SMI group (63.2% vs. 20.0%, P = 0.006). Univariable and multivariable logistic regression analyses revealed that a low SMI was an independent risk factor for FN (odds ratio, 7.178; 95% confidence interval, 1.272-40.507; P = 0.026). In addition, the frequency of dose reduction in DCF therapy was significantly higher in the low-SMI group (68.4% vs. 35.0%, P = 0.037). CONCLUSION: Low SMI is an independent risk factor for FN in patients with esophageal cancer receiving DCF therapy.


Assuntos
Neoplasias Esofágicas , Neutropenia Febril , Masculino , Feminino , Humanos , Cisplatino , Docetaxel , Estudos Retrospectivos , Fluoruracila , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Esofágicas/tratamento farmacológico , Neutropenia Febril/tratamento farmacológico
20.
Support Care Cancer ; 31(5): 283, 2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37074471

RESUMO

PURPOSE: Pegylated liposomal doxorubicin (PLD)-induced hand-foot syndrome (HFS) frequently lowers the quality of life of ovarian cancer patients. Wrist and ankle cooling, having a limited preventive effect, has been the commonest supportive HFS care. In this study, we retrospectively assessed the primary preventive effect of a combination of regional cooling and oral dexamethasone therapy (cooling + oral Dex) on HFS. METHODS: This study is a single-arm retrospective, observational study. Recurrent ovarian cancer patients were administered PLD ± bevacizumab. We retrospectively examined the efficacy of hands and feet cooling (from the start of PLD to the end) + oral Dex (day 1-5: 8 mg/day, day 6, 7: 4 mg/day) for primary HFS prevention. RESULTS: This study included 74 patients. The initial dose of PLD was 50 mg/m2 and 40 mg/m2 for 32 (43.2%) and 42 (56.8%) patients, respectively. HFS of Grade ≥ 2 and Grade ≥ 3 developed in five (6.8%) and one (1.4%) patient(s), respectively. The incidence of ≥ Grade 2 and ≥ Grade 3 HFS was much lower than those reported in previous studies. Dose reduction was required in 13 patients (17.6%) mainly because of neutropenia or mucositis; there was no HFS-induced dose reduction. Meanwhile, PLD therapy was discontinued mainly because of interstitial pneumonia (4 patients) and HFS (one patient). CONCLUSIONS: We demonstrated the efficacy of regional cooling and oral Dex for primary prevention of PLD-induced HFS. Although future prospective studies are needed to confirm its efficacy, this combination therapy can be considered for primary prevention of HFS in ovarian cancer patients on PLD.


Assuntos
Síndrome Mão-Pé , Neoplasias Ovarianas , Feminino , Humanos , Síndrome Mão-Pé/etiologia , Síndrome Mão-Pé/prevenção & controle , Síndrome Mão-Pé/tratamento farmacológico , Antibióticos Antineoplásicos/uso terapêutico , Estudos Retrospectivos , Qualidade de Vida , Recidiva Local de Neoplasia/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Doxorrubicina/uso terapêutico , Polietilenoglicóis/uso terapêutico , Dexametasona/uso terapêutico , Prevenção Primária , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos
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