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1.
Bioorg Med Chem Lett ; 80: 129117, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36584791

RESUMO

The conserved N-linked glycan at the Fc domain of recombinant monoclonal antibodies is an attractive target for site-specific payload conjugation for preparation of homogenous antibody-drug conjugates (ADCs). Here, we report a novel ADC constructing strategy, named "ez-ADiCon", that is achieved by one-step enzymatic transglycosylation of a payload-preloaded bi-antennary glycan oxazoline onto a deglycosylated antibody. In this method, a mixture of different glycoforms of the Fc-glycan is replaced with a pre-defined payload-linked glycan. Since two payloads are linked on each donor glycan substrate, efficient conjugation results in a highly homogenous ADC with mostly-four drug molecules per antibody, facilitating hydrophobic interaction chromatography analysis and purification. We validated this conjugation strategy using Monomethyl auristatin E (MMAE) and an anti-Human epidermal growth factor receptor 2 (anti-Her2) antibody as the model ADC components and demonstrated its target-specific in vitro cytotoxicity. Our novel conjugation strategy, ez-ADiCon, provides a new approach for the preparation of next generation ADCs.


Assuntos
Antineoplásicos , Imunoconjugados , Imunoconjugados/química , Antineoplásicos/química , Anticorpos Monoclonais/química , Interações Hidrofóbicas e Hidrofílicas , Polissacarídeos/química
2.
Esophagus ; 20(2): 325-332, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36253658

RESUMO

BACKGROUND AND AIMS: Multiple biopsies are recommended for the diagnosis of eosinophilic esophagitis (EoE) because inflammatory changes are frequently patchy. Reports on EoE using endocytoscopy (ECS) are limited. This present study aimed to assess if diagnostic yield improves by adding ECS on conventional white light imaging (WLI) in patients with esophageal eosinophilia (EE). METHODS: A total of 284 biopsy specimens from 71 patients with a known diagnosis of EE were enrolled and divided into the WLI group (156 specimens) or the ECS group (128 specimens). Four biopsies from 5 and 10 cm proximal to the esophagogastric junction were taken from each patient. In the ECS group, the biopsy was performed where bilobed nuclei were observed. The biopsy sensitivity for EE, eosinophil count of a single specimen and the biopsy sensitivity of each endoscopic finding were evaluated between both groups. RESULTS: The sensitivity of a single biopsy specimen was higher in the ECS group than that of the WLI group (62.5 vs. 41.7%, P < 0.001). In addition, the median eosinophil count in the ECS group was significantly higher [19 vs. 6.5/high-power field (HPF), P < 0.001]. For each endoscopic finding, ECS-based biopsy had higher sensitivity than that of WLI in the diagnosis of edema (33.1 vs. 11.3%, P = 0.007) and linear furrows (75.8 vs. 52%, P = 0.005). CONCLUSION: This study showed that adding ECS to WLI improved the biopsy sensitivity and eosinophil detection in patients with EE.


Assuntos
Esofagite Eosinofílica , Esofagoscopia , Humanos , Esofagoscopia/métodos , Biópsia/métodos , Esofagite Eosinofílica/diagnóstico
3.
Sex Transm Dis ; 49(1): e29-e33, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34074999

RESUMO

ABSTRACT: We report on hepatitis C virus genotype 2c infection in 12 human immunodeficiency virus-infected men who have sex with men in Tokyo, Japan. The uncommon strains from the 12 patients were genetically clustered; they suggested an emerging outbreak in this population at high risk of sexually transmitted infections.


Assuntos
Infecções por HIV , Hepatite C , Minorias Sexuais e de Gênero , Genótipo , HIV , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Hepacivirus/genética , Hepatite C/epidemiologia , Homossexualidade Masculina , Humanos , Japão/epidemiologia , Masculino , Tóquio/epidemiologia
4.
BMC Neurol ; 21(1): 242, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34172002

RESUMO

BACKGROUND: Levodopa-carbidopa intestinal gel (LCIG) treatment, a unique drug delivery system for patients with advanced Parkinson's disease (PD), is covered by health insurance in Japan since September 2016. Various LCIG procedure/device-associated adverse events (AEs) have been reported; however, reports on their treatment have been limited. This is the first multicenter study to clarify the frequency and timing of device-related AEs. METHODS: Between September 2016 and December 2018, 104 patients introduced to the LCIG treatment for advanced PD in 11 hospitals were included. The patients' characteristics, AEs incidence, AEs time, and tube exchange time were investigated. RESULTS: The median follow-up period was 21.5 months. Minor AE cases were 29.4%, whereas major AE cases were 43.1%. Majority of major AEs (n = 55, 94.8%) were managed with endoscopic treatment, such as tube exchange. Few severe AEs required surgical treatment (n =3, 5.2%). The mean (range) exposure to percutaneous endoscopic gastrojejunostomy (PEG-J) was 14.7 (0-33) months. One year after the LCIG treatment introduction, 55 patients (54.0%) retained the original PEG-J tube. The mean PEG-J tube exchange time was 10.8 ± 7.0 months in all patients, 11.6 ± 4.7 and 10.5 ± 7.7 months in patients with scheduled exchange and who underwent exchange due to AEs, respectively. CONCLUSIONS: Some device-related AEs occurred during the LCIG treatment; however, only few were serious, most of which could be treated with simple procedures or tube replacement with endoscopy. Therefore, the LCIG treatment is feasible and safe and is a unique treatment option for PD, requiring endoscopists' understanding and cooperation.


Assuntos
Antiparkinsonianos , Carbidopa , Derivação Gástrica , Géis , Levodopa , Doença de Parkinson/tratamento farmacológico , Antiparkinsonianos/administração & dosagem , Antiparkinsonianos/efeitos adversos , Antiparkinsonianos/uso terapêutico , Carbidopa/administração & dosagem , Carbidopa/efeitos adversos , Carbidopa/uso terapêutico , Combinação de Medicamentos , Derivação Gástrica/efeitos adversos , Derivação Gástrica/métodos , Géis/administração & dosagem , Géis/efeitos adversos , Géis/uso terapêutico , Humanos , Levodopa/administração & dosagem , Levodopa/efeitos adversos , Levodopa/uso terapêutico , Estudos Retrospectivos
5.
Digestion ; 102(4): 563-571, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32894837

RESUMO

INTRODUCTION: Patients with esophageal squamous cell carcinoma (ESCC) have various comorbidities. Thus, it is necessary to determine the appropriateness of performing treatment based on the patient's general condition. AIM: This study aimed to clarify the prognostic predictors of ESCC indicated for endoscopic submucosal dissection (ESD). METHODS: This retrospective study enrolled 241 patients with superficial ESCC endoscopically diagnosed as ESD-indicated lesions at the Nagoya University Hospital between January 2007 and December 2017. We evaluated the 3- and 5-year overall survival (OS) rates and prognostic predictors, such as the Prognostic Nutritional Index (PNI), Charlson Comorbidity Index (CCI), Psoas Muscle Index, and Controlling Nutritional Status score. Furthermore, we created a score-based classification using the prognostic predictors identified by multivariate analysis, and the 3- and 5-year OS rates were compared among the calculated scores. RESULTS: In the multivariate analysis, PNI < 45 (hazard ratio [HR]: 2.39; 95% confidence interval [CI]: 1.28-4.46; p = 0.006) and CCI ≥ 3 (HR: 4.42; 95% CI: 2.40-8.12; p < 0.001) were significantly associated with the OS. Based on the HR, 0 and 1 were assigned to PNI and 0, 2, and 4 were assigned to CCI, and the score classification of 0-5 points was created. The 3- and 5-year OS rates in patients with a score 3 were significantly higher than in those with scores 4 and 5. As a result of scoring, the prognosis was stratified; the 3- and 5-year OS rates in patients with scores 4 and 5, that is, CCI ≥ 6, were clearly low, at approximately 10%. CONCLUSIONS: CCI and PNI can be prognostic predictors of patients with superficial ESCC indicated for ESD. Observation without ESD might be an acceptable strategy among patients with CCI ≥ 6.


Assuntos
Ressecção Endoscópica de Mucosa , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Neoplasias Esofágicas/cirurgia , Carcinoma de Células Escamosas do Esôfago/cirurgia , Humanos , Prognóstico , Estudos Retrospectivos , Resultado do Tratamento
6.
Gut ; 67(2): 372-379, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-27797937

RESUMO

OBJECTIVE: Although HCV is a major cause of chronic liver disease worldwide, there is currently no prophylactic vaccine for this virus. Thus, the development of an HCV vaccine that can induce both humoural and cellular immunity is urgently needed. To create an effective HCV vaccine, we evaluated neutralising antibody induction and cellular immune responses following the immunisation of a non-human primate model with cell culture-generated HCV (HCVcc). DESIGN: To accomplish this, 10 common marmosets were immunised with purified, inactivated HCVcc in combination with two different adjuvants: the classically used aluminum hydroxide (Alum) and the recently established adjuvant: CpG oligodeoxynucleotide (ODN) wrapped by schizophyllan (K3-SPG). RESULTS: The coadministration of HCVcc with K3-SPG efficiently induced immune responses against HCV, as demonstrated by the production of antibodies with specific neutralising activity against chimaeric HCVcc with structural proteins from multiple HCV genotypes (1a, 1b, 2a and 3a). The induction of cellular immunity was also demonstrated by the production of interferon-γ mRNA in spleen cells following stimulation with the HCV core protein. These changes were not observed following immunisation with HCVcc/Alum preparation. No vaccination-related abnormalities were detected in any of the immunised animals. CONCLUSIONS: The current preclinical study demonstrated that a vaccine included both HCVcc and K3-SPG induced humoural and cellular immunity in marmosets. Vaccination with this combination resulted in the production of antibodies exhibiting cross-neutralising activity against multiple HCV genotypes. Based on these findings, the vaccine created in this study represents a promising, potent and safe prophylactic option against HCV.


Assuntos
Anticorpos Neutralizantes/sangue , Hepacivirus/imunologia , Anticorpos Anti-Hepatite C/sangue , Vacinação , Vacinas contra Hepatite Viral/imunologia , Adjuvantes Imunológicos/administração & dosagem , Hidróxido de Alumínio/administração & dosagem , Hidróxido de Alumínio/imunologia , Animais , Callithrix , Células HEK293 , Antígenos da Hepatite C/imunologia , Humanos , Imunidade Celular , Interferon gama/genética , Camundongos , RNA Mensageiro/metabolismo , Baço/citologia , Proteínas do Core Viral/imunologia
7.
Cancer Sci ; 108(4): 581-589, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28129467

RESUMO

Malignant ascites manifests as an end-stage event during the progression of a number of cancers and lacks a generally accepted standard therapy. Interferon-ß (IFN-ß) has been used to treat several cancer indications; however, little is known about the efficacy of IFN-ß on malignant ascites. In the present study, we report on the development of a novel, engineered form of human and murine IFN-ß, each conjugated with a polyethylene glycol molecule (PEG-hIFN-ß and PEG-mIFN-ß, respectively). We provide evidence that these IFN-ß molecules retain anti-viral potency comparable to unmodified IFN-ß in vitro and manifested improved pharmacokinetics in vivo. Interestingly, PEG-mIFN-ß significantly inhibited the accumulation of ascites fluid and vascular permeability of the peritoneal membrane in models of ovarian cancer and gastric cancer cell xenograft mice. We further show that PEG-hIFN-ß directly suppresses VEGF165 -induced hyperpermeability in a monolayer of human vascular endothelial cells and that PEG-mIFN-ß enhanced gene expression for a number of cell adhesion related molecules in mouse vascular endothelial cells. Taken together, these findings unveil a hitherto unrecognized potential of IFN-ß in maintaining vascular integrity, and provide proof-of-mechanism for a novel and long-acting pegylated hIFN-ß for the therapeutic treatment of malignant ascites.


Assuntos
Ascite/tratamento farmacológico , Interferon beta/farmacologia , Neoplasias Peritoneais/tratamento farmacológico , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , 5'-Nucleotidase/metabolismo , Animais , Antivirais/química , Antivirais/farmacocinética , Antivirais/farmacologia , Área Sob a Curva , Ascite/patologia , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular/efeitos dos fármacos , Células Cultivadas , Expressão Gênica/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Interferon beta/química , Interferon beta/farmacocinética , Taxa de Depuração Metabólica , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Nus , Camundongos SCID , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Neoplasias Peritoneais/secundário , Polietilenoglicóis/química , Fator A de Crescimento do Endotélio Vascular/farmacologia
8.
Artigo em Inglês | MEDLINE | ID: mdl-28373196

RESUMO

Although nucleot(s)ide analogues and pegylated interferon alpha 2a (PEG-IFN-α2a) can suppress hepatitis B virus (HBV) replication, it is difficult to achieve complete HBV elimination from hepatocytes. A novel site-specific pegylated recombinant human IFN-ß (TRK-560) was recently developed. In the present study, we evaluated the antiviral effects of TRK-560 on HBV replication in vitro and in vivo. In vitro and in vivo HBV replication models were treated with antivirals including TRK-560, and changes in HBV markers were evaluated. To analyze antiviral mechanisms, cDNA microarray analysis and an enzyme-linked immunoassay (ELISA) were performed. TRK-560 significantly suppressed the production of intracellular HBV replication intermediates and extracellular HBV surface antigen (HBsAg) (P < 0.001 and P < 0.001, respectively), and the antiviral effects of TRK-560 were enhanced in combination with nucleot(s)ide analogues, such as entecavir and tenofovir disoproxil fumarate. The reduction in HBV DNA levels by TRK-560 treatment was significantly higher than that by PEG-IFN-α2a treatment both in vitro and in vivo (P = 0.004 and P = 0.046, respectively), and intracellular HBV covalently closed circular DNA (cccDNA) reduction by TRK-560 treatment was also significantly higher than that by PEG-IFN-α2a treatment in vivo (P = 0.0495). cDNA microarrays and ELISA for CXCL10 production revealed significant differences between TRK-560 and PEG-IFN-α2a in the induction potency of interferon-stimulated genes. TRK-560 shows a stronger antiviral potency via higher induction of interferon-stimulated genes and stronger stimulation of immune cell chemotaxis than PEG-IFN-α2a. As HBsAg loss and HBV cccDNA eradication are important clinical goals, these results suggest a potential role for TRK-560 in the development of more effective treatment for chronic hepatitis B infection.


Assuntos
Antivirais/farmacologia , Antígenos de Superfície da Hepatite B/metabolismo , Vírus da Hepatite B/efeitos dos fármacos , Hepatite B Crônica/tratamento farmacológico , Interferon-alfa/farmacologia , Polietilenoglicóis/farmacologia , Animais , Linhagem Celular Tumoral , Quimiocina CXCL10/biossíntese , DNA Circular/metabolismo , DNA Viral/metabolismo , Células Hep G2 , Humanos , Camundongos , Camundongos SCID , Camundongos Transgênicos , Proteínas Recombinantes/farmacologia , Resultado do Tratamento , Carga Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
9.
J Pharmacol Sci ; 127(3): 377-81, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25837937

RESUMO

This study was conducted to identify the characteristic pharmacological features of GT-0198 that is phenoxymethylbenzamide derivatives. GT-0198 inhibited the function of glycine transporter 2 (GlyT2) in human GlyT2-expressing HEK293 cells and did not bind various major transporters or receptors of neurotransmitters in a competitive manner. Thus, GT-0198 is considered to be a comparatively selective GlyT2 inhibitor. Intravenous, oral, and intrathecal injections of GT-0198 decreased the pain-related response in a model of neuropathic pain with partial sciatic nerve ligation. This result suggests that GT-0198 has an analgesic effect. The analgesic effect of GT-0198 was abolished by the intrathecal injection of strychnine, a glycine receptor antagonist. Therefore, GT-0198 is considered to exhibit its analgesic effect via the activation of a glycine receptor by glycine following presynaptic GlyT2 inhibition in the spinal cord. In summary, GT-0198 is a structurally novel GlyT2 inhibitor bearing a phenoxymethylbenzamide moiety with in vivo efficacy in behavioral models of neuropathic pain.


Assuntos
Analgésicos , Benzamidas/administração & dosagem , Benzamidas/farmacologia , Proteínas da Membrana Plasmática de Transporte de Glicina/antagonistas & inibidores , Neuralgia/tratamento farmacológico , Piperidinas/administração & dosagem , Piperidinas/farmacologia , Animais , Benzamidas/antagonistas & inibidores , Benzamidas/química , Modelos Animais de Doenças , Células HEK293 , Humanos , Ligadura , Masculino , Camundongos Endogâmicos ICR , Fenoxibenzamina , Piperidinas/antagonistas & inibidores , Piperidinas/química , Nervo Isquiático , Medula Espinal , Estricnina/farmacologia
10.
Bioorg Med Chem Lett ; 24(18): 4603-4606, 2014 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-25176190

RESUMO

We describe the discovery of phenoxymethylbenzamide derivatives as a novel class of glycine transporter type-2 (GlyT-2) inhibitors. We found hit compound 1 (human GlyT-2, IC50=4040 nM) in our library and converted its 1-(1-(naphthalen-2-ylmethyl)piperidin-4-yl)pyrrolidin-3-yl group to an 1-(N,N-dimethylaminopropyl)piperidyl group and its tert-butyl group to a trifluoromethyl group to obtain N-(1-(3-(dimethylamino)propyl)piperidin-4-yl)-4-((4-(trifluoromethyl)phenoxy)methyl)benzamide (20). Compound 20 showed good inhibitory activity against human GlyT-2 (IC50=15.3 nM) and exhibited anti-allodynia effects in a mouse neuropathic pain model.


Assuntos
Benzamidas/farmacologia , Descoberta de Drogas , Proteínas da Membrana Plasmática de Transporte de Glicina/antagonistas & inibidores , Benzamidas/síntese química , Benzamidas/química , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Relação Estrutura-Atividade
11.
Exp Parasitol ; 135(4): 695-700, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24184078

RESUMO

The two-domain taurocyamine kinase (TK) from Paragonimus westermani was suggested to have a unique substrate binding mechanism. We performed site-directed mutagenesis on each domain of this TK and compared the kinetic parameters Km(Tc) and Vmax with that of the wild-type to determine putative amino acids involved in substrate recognition and binding. Replacement of Y84 on domain 1 and Y87 on domain 2 with R resulted in the loss of activity for the substrate taurocyamine. Y84E mutant has a dramatic decrease in affinity and activity for taurocyamine while Y87E has completely lost catalytic activity. Substituting H and I on the said positions also resulted in significant changes in activity. Mutation of the residues A59 on the GS region of domain 1 also caused significant decrease in affinity and activity while mutation on the equivalent position on domain 2 resulted in complete loss of activity.


Assuntos
Paragonimus westermani/enzimologia , Fosfotransferases (Aceptor do Grupo Nitrogenado)/metabolismo , Estrutura Terciária de Proteína , Taurina/análogos & derivados , Tirosina , Sequência de Aminoácidos , Animais , Sequência de Bases , Sequência Conservada , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Fosfotransferases (Aceptor do Grupo Nitrogenado)/química , Fosfotransferases (Aceptor do Grupo Nitrogenado)/genética , Estrutura Terciária de Proteína/genética , Alinhamento de Sequência , Especificidade por Substrato , Taurina/metabolismo , Tirosina/química , Tirosina/genética
12.
Adv Exp Med Biol ; 765: 251-256, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22879041

RESUMO

Several distinctive activity patterns have been observed in the brain at rest. The aim of this study was to determine whether the STAI index can be predicted from changes in the oxy- and deoxy-hemoglobin (Hb) concentrations by using two-channel prefrontal cortex (PFC) NIRS data for the resting state. The study population comprised 19 subjects. Each subject performed four trials, each of which consisted of resting with no task for 3 min. Data were acquired using a portable NIRS device equipped with two channels. The prediction algorithm was derived within a Bayesian machine learning framework. The prediction errors for seven subjects were not greater than 5.0. Because the STAI index varied between 20 and 80, these predictions appeared reasonable. The present method allowed prediction of mental status based on the NIRS data at resting condition obtained in the PFC.


Assuntos
Ansiedade/fisiopatologia , Teorema de Bayes , Circulação Cerebrovascular/fisiologia , Córtex Pré-Frontal/fisiopatologia , Descanso/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho , Adulto , Feminino , Hemoglobinas/metabolismo , Humanos , Masculino , Oxiemoglobinas/metabolismo , Inquéritos e Questionários , Adulto Jovem
13.
Nagoya J Med Sci ; 85(1): 134-140, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36923622

RESUMO

Circumferential resection of a >5-cm longitudinal mucosal defect following esophageal endoscopic submucosal dissection (ESD) is a risk factor for refractory stenosis. Circumferential ESD was performed in 3 patients with 64, 69, and 70 mm longitudinal mucosal defects. A local steroid injection was used to treat the postoperative ulcer, followed by an oral steroid. In all three cases, the ulcer healed without the need for endoscopic dilation. A combination of local injection and oral steroids effectively prevented esophageal stenosis in patients with high-risk stenosis after ESD.


Assuntos
Neoplasias Esofágicas , Estenose Esofágica , Humanos , Constrição Patológica , Úlcera/complicações , Neoplasias Esofágicas/cirurgia , Estenose Esofágica/etiologia , Estenose Esofágica/prevenção & controle
14.
Biochim Biophys Acta ; 1814(10): 1219-25, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21684357

RESUMO

In order to investigate the residues associated with binding of the substrate taurocyamine in Arenicola mitochondrial taurocyamine kinase (TK), we performed Ala-scanning of the amino acid sequence HTKTV at positions 67-71 on the GS loop, and determined apparent K(m) and V(max) (appK(m) and appV(max), respectively) of the mutant forms for the substrates taurocyamine and glycocyamine. The appK(m) values for taurocyamine of the K69A, T70A and V71A mutants were significantly increased as compared with wild-type, suggesting that these residues are associated with taurocyamine binding. Of special interest is a property of V71A mutant: its catalytic efficiency for glycocyamine was twice that for taurocyamine, indicating that the V71A mutant acts like a glycocyamine kinase, rather than a TK. The role of the amino acid residue K95 of Arenicola MiTK was also examined. K95 was replaced with R, H, Y, I, A and E. K95R, K95H and K95I have a 3-fold higher affinity for taurocyamine, and activity was largely lost in K95E. On the other hand, the K95Y mutant showed a rather unique feature; namely, an increase in substrate concentration caused a decrease in initial velocity of the reaction (substrate inhibition). This is the first report on the key amino acid residues responsible for taurocyamine binding in mitochondrial TK.


Assuntos
Sequência de Aminoácidos/fisiologia , Fosfotransferases (Aceptor do Grupo Nitrogenado)/química , Fosfotransferases (Aceptor do Grupo Nitrogenado)/metabolismo , Poliquetos/enzimologia , Taurina/análogos & derivados , Substituição de Aminoácidos/fisiologia , Animais , Sítios de Ligação/genética , Proteínas Mitocondriais/química , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Modelos Biológicos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Fosfotransferases (Aceptor do Grupo Nitrogenado)/genética , Poliquetos/genética , Poliquetos/metabolismo , Ligação Proteica/genética , Ligação Proteica/fisiologia , Estrutura Terciária de Proteína/genética , Análise de Sequência de Proteína , Homologia de Sequência de Aminoácidos , Taurina/metabolismo
15.
BMC Cell Biol ; 13: 3, 2012 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-22296827

RESUMO

BACKGROUND: As many invertebrate species have multipotent cells that undergo cell growth and differentiation during regeneration and budding, many unique and interesting homeostatic factors are expected to exist in those animals. However, our understanding of such factors and global mechanisms remains very poor. Single zooids of the tunicate, Polyandrocarpa misakiensis, can give off as many as 40 buds during the life span. Bud development proceeds by means of transdifferentiation of very limited number of cells and tissues. TC14-3 is one of several different but closely related polypeptides isolated from P. misakiensis. It acts as a cytostatic factor that regulates proliferation, adhesion, and differentiation of multipotent cells, although the molecular mechanism remains uncertain. The Polycomb group (PcG) genes are involved in epigenetic control of genomic activity in mammals. In invertebrates except Drosophila, PcG and histone methylation have not been studied so extensively, and genome-wide gene regulation is poorly understood. RESULTS: When Phe(65) of TC14-3 was mutated to an acidic amino acid, the resultant mutant protein failed to dimerize. The replacement of Thr(69) with Arg(69) made dimers unstable. When Glu(106) was changed to Gly(106), the resultant mutant protein completely lost Ca(2+) binding. All these mutant proteins lacked cytostatic activity, indicating the requirement of protein dimerization and calcium for the activity. Polyandrocarpa Eed, a component of PcG, is highly expressed during budding, like TC14-3. When wild-type and mutant TC14-3s were applied in vivo and in vitro to Polyandrocarpa cells, only wild-type TC14-3 could induce Eed without affecting histone methyltransferase gene expression. Eed-expressing cells underwent trimethylation of histone H3 lysine27. PmEed knockdown by RNA interference rescued cultured cells from the growth-inhibitory effects of TC14-3. CONCLUSION: These results show that in P. misakiensis, the cytostatic activity of TC14-3 is mediated by PmEed and resultant histone modification, and that the gene expression requires both the protein dimerization and Ca(2+)-binding of TC14-3. This system consisting of a humoral factor, PcG, and histone methylation would contribute to the homeostatic regulation of cell growth and terminal differentiation of invertebrate multipotent cells.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Histonas/metabolismo , Proteínas Repressoras/biossíntese , Urocordados/genética , Animais , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/genética , Diferenciação Celular , Expressão Gênica , Metilação , Mutação/genética , Proteínas do Grupo Polycomb , Multimerização Proteica/fisiologia , Proteínas Repressoras/genética , Urocordados/metabolismo , Urocordados/fisiologia
16.
Artigo em Inglês | MEDLINE | ID: mdl-34364990

RESUMO

Among 28 groups of eukaryotes, apart from Metazoa, phosphagen kinase (PKs) is distributed in only a few protist groups, including the Choanomonada with the closest affinity to metazoans. To clarify the origin of metazoan PKs, we performed a database search and focused on 11 sequences of PK homologs from five groups of protists: the Choanomonada, Alveolata, Haptophyta, Stramenopiles, and Cryptophyta. The recombinant enzymes were prepared to determine their substrate specificity. Emiliania (Haptophyta), Anophryoides, Pseudocohnilembus, Vitrella and Chromera (Alveolata), and Monosiga (Choanomonada) all contained a gene for arginine kinase (AK). In contrast, Aphanomyces, Albugo and Ectocarpus (Stramenopiles), and Guillardia (Cryptophyta) possessed a gene for taurocyamine kinase (TK). The Guillardia TK enzyme exhibited rather strong substrate inhibition toward taurocyamine, which was analyzed using the most likely kinetic model. This was the first report of substrate inhibition in a TK. Together with the research results from other groups, the AK, TK, or creatine kinase (CK) activities have been observed sporadically in at least six groups of protists. However, it is not clear the three enzyme activities were emerged early in the evolution and divergence of protist groups, or some of enzyme activities were introduced to the protists by horizontal gene transfer. In addition, we found that seven protist enzymes examined in this study possess a myristoylation signaling sequence at the N-terminus. The amino-acid sequence around the guanidine-specificity region and the key residue at 89th position of the protist AK and CK were homologous to those of the metazoan enzymes, but those for protist TKs were different indicating that the latter evolved independently.


Assuntos
Haptófitas , Estramenópilas , Animais , Criptófitas , Evolução Molecular , Filogenia , Estramenópilas/genética
17.
Artigo em Inglês | MEDLINE | ID: mdl-35598705

RESUMO

The genome of the unicellular molluscan parasite Perkinsus marinus contains at least five genes coding for putative creatine kinases (CK), a phosphoryl transfer enzyme which plays a key role in cellular energy transactions. Expression and kinetic analyses of three of the P. marinus CKs revealed them to be true CKs with catalytic properties in the range of typical metazoan CKs. A sequence comparison of the P. marinus CKs with a range of CK dimers and other dimeric phosphoryl transfer enzymes in this family (phosphagen kinases) showed that the P. marinus CKs lacked some of the critical residues involved in dimer stabilization, a trait all previously characterized CKs share. Size exclusion chromatography of all three expressed P. marinus CK constructs indicated they are monomeric, consistent with the observed lack of some critical dimer stabilizing residues. Phylogenetic analyses of the P. marinus CKs and putative dinoflagellate CKs with a broad range of monomeric and dimeric phosphagen kinases revealed that the Perkinsus CKs form a distinct, well-supported clade with dinoflagellate CKs which also lack the dimer stabilizing residues. Analysis of the genomic data for P. marinus showed the presence of putative genes for the two enzymes associated with creatine biosynthesis. CK in higher organisms plays a critical role in energy buffering in cell types displaying high and variable rates of ATP turnover. The presence of multiple CKs and the creatine biosynthetic pathway in P. marinus indicates that this unicellular parasite has the full complement of molecular machinery for CK-mediated energy buffering.


Assuntos
Alveolados , Alveolados/metabolismo , Sequência de Aminoácidos , Animais , Creatina , Creatina Quinase/genética , Filogenia
18.
Artigo em Inglês | MEDLINE | ID: mdl-34371154

RESUMO

Opheline kinase (OK) is one of the phosphagen kinases (PKs) restricted to annelids, but the amino acid sequence has not been determined yet. The OK enzyme was isolated in 1966 from the polychaete Ophelia neglecta (Opheliidae) and shown to have somewhat broader activities for the various substrates opheline, lombricine and taurocyamine. To determine the OK sequence, we analyzed the RNA sequencing data for Ophelina sp. and Thoracophelia sp., belonging to Opheliidae. Four PK sequences, namely, taurocyamine kinase (TK), creatine kinase (CK), mitochondrial CK (MiCK) and putative OK, were identified in both species, and the recombinant Ophelina enzymes were expressed in E. coli and purified. Since the substrate opheline was not commercially available, we used the partial activity toward taurocyamine to infer the enzyme specificity. The putative Ophelina OK showed lower activity to taurocyamine with a Vmax/Km nearly identical to a previously published value for an OK from a related species Ophelia neglecta. Under the same conditions, the true Ophelina TK showed much higher activity. Thus, the putative Ophelina enzyme was determined to be OK. The amino acid sequence alignment indicated that Ophelina and Thoracophelia OKs have five amino acid deletions in the GS region, like those of LKs and AKs, and the guanidino substrate specific residue was Lys, the same as LKs. In the phylogenetic tree constructed from annelid PK amino acid sequences, the OK sequences formed a distinct cluster, and it was placed near the TK and lombricine kinase (LK) clusters. This is the first report of the amino acid sequence for the OK enzyme.


Assuntos
Anelídeos , Arginina Quinase , Sequência de Aminoácidos , Animais , Anelídeos/genética , Arginina Quinase/metabolismo , Creatina Quinase/genética , Escherichia coli/metabolismo , Filogenia
19.
Pharmacol Res Perspect ; 10(6): e01038, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36507603

RESUMO

The innate immune system has an emerging role as a mediator of neuro-immune communication and a therapeutic target for itch. Toll-like receptor 3 (TLR3) plays an important role in itch, as shown in TLR3 knock-out mice. In this study, to evaluate effects of TLR3 inhibitors on histamine-independent itch, we used two kinds of isothiocyanate (ITC). Both phenethyl isothiocyanate (PEITC) and sulforaphane (SFN) inhibited Poly I:C (PIC)-induced signaling in the RAW264.7 cell line. We then investigated the anti-pruritic effect of these compounds on PIC- and chloroquine (CQ)-induced scratching behavior. PEITC and SFN both suppressed PIC-evoked scratching behavior in mice, and PEITC also inhibited CQ-induced acute itch. Finally, we examined the oxazolone-induced chronic itch model in mice. Surprisingly, oral dosing of both compounds suppressed scratching behaviors that were observed in mice. Our findings demonstrate that TLR3 is a critical mediator in acute and chronic itch transduction in mice and may be a promising therapeutic target for pruritus in human skin disorders. It is noteworthy that SFN has potential for use as an antipruritic as it is a phytochemical that is used as a supplement.


Assuntos
Antipruriginosos , Receptor 3 Toll-Like , Animais , Humanos , Camundongos , Antipruriginosos/farmacologia , Antipruriginosos/uso terapêutico , Cloroquina , Camundongos Knockout , Prurido/induzido quimicamente , Prurido/tratamento farmacológico , Prurido/metabolismo , Pele/metabolismo , Receptor 3 Toll-Like/uso terapêutico
20.
Intern Emerg Med ; 17(2): 423-430, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34363550

RESUMO

Various scoring systems have been developed to predict the need for endoscopic treatment in patients with non-variceal upper gastrointestinal bleeding (NVUGIB). However, they have rarely been applied in clinical practice because the processes are complicated. The aim of this study was to establish a simple scoring system that predicts the need for endoscopic intervention in patients with NVUGIB. We retrospectively enrolled 509 consecutive patients with suspected NVUGIB who underwent emergency endoscopy. In the development cohort (from January 2016 to December 2018), risk factors that predict the need for endoscopic intervention were determined from 349 patients' data by multivariate logistic regression analysis. This led to the development of a novel scoring system named the Nagoya University score (N score). In the validation cohort (from January 2019 to September 2020), we evaluated the diagnostic value of the N score, the Hirosaki score, and the Glasgow-Blatchford scores (GBS) by receiver operating characteristic (ROC) curves using another 160 patients' data. Multivariate logistic regression analysis revealed syncope, hematemesis, blood urea nitrogen (BUN), and BUN/Cr as significant predictive factors for endoscopic intervention. In the validation study, the N score was superior to the GBS and equal to the Hirosaki score in predicting the endoscopic intervention (AUC, N score 0.776 [95% CI 0.702-0.851] vs. GBS 0.615 [0.523-0.708], Hirosaki 0.719 [0.636-0.803]). The N score revealed a sensitivity of 84.5% and a specificity of 61.8%. Our N score, which is consisted of only four factors, would select patients who require endoscopic intervention with high probability.


Assuntos
Endoscopia Gastrointestinal , Hemorragia Gastrointestinal , Hemorragia Gastrointestinal/diagnóstico , Hemorragia Gastrointestinal/terapia , Humanos , Prognóstico , Curva ROC , Estudos Retrospectivos , Medição de Risco , Índice de Gravidade de Doença
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