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PURPOSE: Finasteride and dutasteride are used to treat benign prostatic hyperplasia (BPH) and reduce the risk of developing prostate cancer. Finasteride blocks only the type 2 form of 5-alpha-reductase, whereas dutasteride blocks both type 1 and 2 forms of the enzyme. Previous studies suggest the possibility that dutasteride may be superior to finasteride in preventing prostate cancer. We directly compared the effects of finasteride and dutasteride on the risk of prostate cancer in patients with BPH using a pooled analysis of 15 real-world databases. MATERIALS AND METHODS: We conducted a multicenter, cohort study of new-users of finasteride and dutasteride. We include patients who were prescribed 5 mg finasteride or dutasteride for the first time to treat BPH and had at least 180 days of prescription. We excluded patients with a history of prostate cancer or a prostate-specific antigen level ≥ 4 ng/mL before the study drug prescription. Cox regression analysis was performed to examine the hazard ratio (HR) for prostate cancer after propensity score (PS) matching. RESULTS: A total of 8,284 patients of new-users of finasteride and 8,670 patients of new-users of dutasteride were included across the 15 databases. In the overall population, compared to dutasteride, finasteride was associated with a lower risk of prostate cancer in both on-treatment and intent-to-treat time-at-risk periods. After 1:1 PS matching, 4,897 patients using finasteride and 4,897 patients using dutasteride were enrolled in the present study. No significant differences were observed for risk of prostate cancer between finasteride and dutasteride both on-treatment (HR=0.66, 95% confidence interval [CI]: 0.44-1.00; p=0.051) and intent-to-treat time-at-risk periods (HR=0.87, 95% CI: 0.67-1.14; p=0.310). CONCLUSIONS: Using real-world databases, the present study demonstrated that dutasteride was not associated with a lower risk of prostate cancer than finasteride in patients with BPH.
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OBJECTIVE: Predicting which young people are likely to use tobacco in the future is critical for prevention and intervention. Although measures for assessing susceptibility to using tobacco have fulfilled this goal for decades, there is almost no standard for the number of items that should be administered, or which items should be administered for which products. This study explored whether brief but psychometrically sound versions of commonly used susceptibility measures can adequately capture the construct relative to longer measures. METHOD: A sample of young people (N = 451; Mage = 16.5 years; 64% females; 65% White) completed 33 susceptibility items, which are designed to assess susceptibility to use different types of tobacco products (cigarette, smokeless tobacco, vaping products, and little cigars/cigarillos) of various flavors (tobacco, menthol, and sweet). RESULTS: Analysis of these 33 items indicated that asking about the likelihood of using each tobacco product class when a best friend offers it (four items in all) captures 98.5% of information that is captured using the longer set of items; asking the best friend question for each product by each flavor category (11 items in all) captures 99.7% of the information. CONCLUSIONS: Depending on research needs, tobacco use susceptibility can be measured with little loss of information by administering a limited set of items assessing the likelihood that a young person will use a tobacco product if a friend offers it for any product-flavor combination. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
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S-Adenosylmethionine (SAM) acts as a methyl donor in living organisms, and S-adenosylmethionine synthetase (MetK) is an essential enzyme for cells, as it synthesizes SAM from methionine and adenosine triphosphate (ATP). This study determined the crystal structures of the apo form and adenosine/triphosphate complex form of MetK from Corynebacterium glutamicum (CgMetK). Results showed that CgMetK has an allosteric inhibitor binding site for the SAM product in the vicinity of the active site and is inhibited by SAM both competitively and noncompetitively. Through structure-guided protein engineering, the CgMetKE68A variant was developed that exhibited an almost complete release of inhibition by SAM with rather enhanced enzyme activity. The crystal structure of the CgMetKE68A variant revealed that the formation of a new hydrogen bond between Tyr66 and Glu102 by the E68A mutation disrupted the allosteric SAM binding site and also improved the protein thermal stability by strengthening the tetramerization of the enzyme.
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Corynebacterium glutamicum , Metionina Adenosiltransferase , Metionina Adenosiltransferase/genética , Metionina Adenosiltransferase/química , Metionina Adenosiltransferase/metabolismo , Corynebacterium glutamicum/genética , Corynebacterium glutamicum/metabolismo , Metionina/metabolismo , S-Adenosilmetionina/metabolismo , Trifosfato de Adenosina/metabolismoRESUMO
It is well-known that some species of lizard have an exceptional ability known as caudal autotomy (voluntary self-amputation of the tail) as an anti-predation mechanism. After amputation occurs, they can regenerate their new tails in a few days. The new tail section is generally shorter than the original one and is composed of cartilage rather than vertebrae bone. In addition, the skin of the regenerated tail distinctly differs from its original appearance. We performed a proteomics analysis for extracts derived from regenerating lizard tail tissues after amputation and found that endoplasmin (ENPL) was the main factor among proteins up-regulated in expression during regeneration. Thus, we performed further experiments to determine whether ENPL could induce chondrogenesis of tonsil-derived mesenchymal stem cells (T-MSCs). In this study, we found that chondrogenic differentiation was associated with an increase of ENPL expression by ER stress. We also found that ENPL was involved in chondrogenic differentiation of T-MSCs by suppressing extracellular signal-regulated kinase (ERK) phosphorylation. [BMB Reports 2022; 55(5): 226-231].
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Lagartos , Células-Tronco Mesenquimais , Animais , Diferenciação Celular , Células Cultivadas , Condrócitos/metabolismo , Condrogênese , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Lagartos/fisiologia , Glicoproteínas de Membrana , Tonsila Palatina/metabolismoRESUMO
With the recent rapid increase in obesity worldwide, metabolic syndrome (MetS) has gained significant importance. MetS is a cluster of obesity-related cardiovascular risk factors including abdominal obesity, atherogenic dyslipidemia, high blood pressure and impaired glucose tolerance. MetS is highly prevalent and strongly associated with an increased risk of developing diabetes and cardiovascular disease, putting a great burden on human society. Therefore, it is very important to reduce MetS risk, which can improve patients' cardiovascular prognosis. The primary and most effective strategy to control each component of MetS is lifestyle change such as losing body weight, keeping regular exercise, adopting a healthy diet, quitting smoking and alcohol drinking in moderation. Many studies have shown that lifestyle modification has improved all components of MetS, and reduces the incidence of diabetes and cardiovascular disease. Here, the Korean Society of CardioMetabolic Syndrome has summarized specific and practical methods of lifestyle modification in the management of MetS in the healthcare field.
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The coding gene for peptidoglycan editing factor (pdeF) is located in the division and cell wall (dcw) cluster, and encodes a protein that has an editing function for misplaced amino acids in peptidoglycan in E. coli. In this study, we determined the crystal structure of PdeF from Bacillus cereus (BcPdeF) at a 1.60 Å resolution. BcPdeF exists as a monomer in solution and consists of two domains: a core domain containing a Pfam motif DUF152 and a smaller subdomain. The X-ray fluorescence spectrum of BcPdeF crystal elucidated that the protein has a Zn2+ ion in its active site and the metal ion was coordinated by two histidine and one cysteine residue. We also performed docking calculations of the N-acetylmuramate (MurNAc)-L-Ser-D-iGlu ligand in the BcPdeF structure and revealed the substrate binding mode of the enzyme. Furthermore, structural comparisons between BcPdeF and human fatty acid metabolism-immunity nexus (FAMIN), which also contains the DUF152 motif in its core domain, provided a structural basis how the two structurally similar proteins have completely different physiological functions.
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Catechol O-methyltransferase (COMT) is an enzyme that transfers a methyl group to the catechol-derivative substrates using S-adenosyl-l-methionine (SAM) and Mg2+. We report the biochemical and structural analysis of COMT from Niastella koreensis (NkCOMT). NkCOMT showed the highest activity with Mg2+, although the enzyme also showed a significant level of activity with Cu2+ and Zn2+. NkCOMT structures complexed with SAH and Mg2+ elucidated how the enzyme stabilized the cosubstrate and the metal ion and revealed that the region near the SAM binding site undergoes conformational changes upon the binding of the cosubstrate and the metal ion. We also identified the catechol binding pocket of the enzyme and explained a broad substrate specificity of the bacterial enzyme and its ability to accommodate the catechol derivatives. In addition, we developed the NkCOMTE211R and NkCOMTE211K variants that showed both enhanced activities and regiospecificity for the production of the para-forms. Our study provides a structural basis for regiospecificity of NkCOMT, which is related with the conformational change upon binding of SAM and Mg2+.
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Catecol O-Metiltransferase , S-Adenosilmetionina , Bacteroidetes , Catecol O-Metiltransferase/genética , Catecol O-Metiltransferase/metabolismo , Especificidade por SubstratoRESUMO
Cysteine is a semiessential amino acid and plays an important role in metabolism and protein structure and has also been applied in various industrial fields, such as pharmaceutical, food, cosmetic, and animal feed industries. Metabolic engineering studies have been conducted for the cysteine production through bacterial fermentation, but studies on the cysteine biosynthetic pathway in microorganisms are limited. We report the biochemical characteristics of cystathionine γ-lyase from Bacillus cereus ATCC 14579 (BcCGL). We also determined the crystal structure of BcCGL in complex with the PLP cofactor and identified the substrate binding mode. We observed that the replacement of the conserved Glu321 residue to alanine showed increased activity by providing wider active site entrance and hydrophobic interaction for the substrate. We suggest that the structural differences of the α13-α14 region in CGL enzymes might determine the active site conformation.
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Bacillus cereus/enzimologia , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Cistationina gama-Liase/química , Cistationina gama-Liase/metabolismo , Bacillus cereus/química , Bacillus cereus/genética , Proteínas de Bactérias/genética , Sítios de Ligação , Domínio Catalítico , Cistationina gama-Liase/genética , Cisteína/metabolismo , Cinética , Especificidade por SubstratoRESUMO
Increased expression levels of constitutively active androgen receptor splice variants (AR-Vs) cause alterations in AR signaling, resulting in drug resistance and failed hormone therapy among patients with advanced prostate cancers. Several available compounds targeting the androgen axis and AR signaling have not demonstrated efficacy in preventing prostate cancer recurrence. Here, we investigated whether a new agent, 6-[6-ethoxy-5-ispropoxy-3,4-dihydroisoquinolin-2[1H)-yl]-N-[6-methylpyridin-2-yl]nicotinamide (EIQPN), has the potential for treating advanced prostate cancer. EIQPN interacted with the AR-activation fragment-1 (AF-1) domain and blocked its androgen-independent activity, robustly decreased the protein levels of AR and variants in prostate cancer cells by inducing AR protein degradation, and inhibited the androgen-independent proliferation of various AR-positive prostate cancer cells. In xenograft mouse models, EIQPN blocked the tumor growth of androgen-independent prostate cancer cells. Overall, these findings indicate that EIQPN could serve as a novel therapeutic agent for advanced recurrent prostate cancers.
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INTRODUCTION: The purpose of this study was to pursue, and to report the results of, mandibular reconstruction and rehabilitation of medication-related osteonecrosis of the jaw (MRONJ) patients having large critical-sized defects of the mandible using a combination of recombinant human bone morphogenetic protein-2 (rhBMP-2) and absorbable collagen sponge (ACS) with surgical miniplate without any grafting materials. CASE PRESENTATION: Three (3) patients aged 67 and 86 (2 patients) presented due to discomfort on the mandible. They all had a medical history of bisphosphonate and steroids treatment orally or intravenously, and all had been diagnosed as MRONJ stage 3. Sequestrectomy and saucerization were performed, and then a surgical miniplate (Hansolmedical, Korea) was adapted and fixed on the sound portion of the mandible. rhBMP-2 was loaded onto an ACS at a dose of 1.5â¯mg/cc. Several rhBMP-2 (Cowellmedi, Korea)/ACS (Ateloplug, TRMkorea, Korea) were placed into the bony defect with a surgical miniplate. All 3 patients recovered without complications. They all exhibited radiographic evidence of bone formation by 3 months postoperatively in every case. CONCLUSIONS: All 3 patients were treated successfully with rhBMP-2/ACS and miniplate without any complications. This protocol reported herein represents a new approach to the surgical treatment of maxillofacial bone defects and deficiencies, especially in MRONJ patients.
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To determine the mechanism of action of the effects of phytoalexins in soybeans, we analyzed α-glucosidase inhibition kinetics using Michaelis-Menten plots and Lineweaver-Burk plots. The results showed that the type of inhibition with glyceollin was competitive, that of genistein was noncompetitive, that of daidzein was uncompetitive, and luteolin showed a mixed mode of action. The Ki values were determined using a Dixon plot as glyceollin, 18.99 µM; genistein, 15.42 µM; luteolin, 16.81 µM; and daidzein, 9.99 µM. Furthermore, potential synergistic effects between glyceollin and the three polyphenols were investigated. A combination of glyceollin and luteolin at a ratio of 3:7 exhibited synergistic effects on α-glucosidase inhibition, having a combination index (CI) of 0.64244, according to the CI-isobologram equation. Collectively, these results showed that a combination of glyceollin and luteolin has the potential to inhibit α-glucosidase activity via a synergistic mode of inhibition.
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Glycine max/enzimologia , Inibidores de Glicosídeo Hidrolases/farmacologia , Sesquiterpenos/farmacologia , Sinergismo Farmacológico , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genisteína/farmacologia , Isoflavonas/farmacologia , Luteolina/farmacologia , Proteínas de Plantas/farmacologia , Pterocarpanos/farmacologia , alfa-Glucosidases/metabolismo , FitoalexinasRESUMO
In Ebstein's anomaly, maximal expansion in the atrialized right ventricle (RV) occurs during early diastole, whereas that of the functional RV occurs in late diastole, resulting in diastolic dyssynchronous expansion (DSE). We quantitatively assessed DSE and identified preoperative factors correlated with persistent DSE after surgery. Seventeen patients diagnosed with Ebstein's anomaly in whom transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) images available were retrospectively analyzed for quantitative DSE assessment and 10 patients who underwent surgery and postoperative TTE available were additionally analyzed for postoperative DSE. Severity of DSE was assessed by the time difference of maximal expansion between the atrialized and functional RV divided by the cardiac cycle length × 100 ("DSE index"). Relations between DSE and, clinical, electrophysiologic parameters and the severity of tricuspid valve (TV) tethering (the RV length / tethering height during diastole: "Tethering index") were assessed. In total patients, median DSE index and tethering index were 30.3 and 2.1 respectively, and the DSE index was correlated with tethering index (rs = 0.664, P = 0.004). In 10 patients who underwent surgery, this association remained after surgery and at 2-year follow up. Tethering index ≥2.5 separated patients with and without persistent DSE. In conclusion, DSE exists in Ebstein's anomaly. DSE index is related to the tethering index and DSE persists postoperatively if tethering index ≥ 2.5. As the persistent DSE might possibly impede the optimal recovery of RV function after surgery, severity of TV tethering should take into account in considering surgery.
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Anomalia de Ebstein/fisiopatologia , Ventrículos do Coração/fisiopatologia , Período Pós-Operatório , Adolescente , Adulto , Diástole , Ecocardiografia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Estudos Retrospectivos , Valva Tricúspide/fisiopatologia , Função Ventricular Direita , Adulto JovemRESUMO
Pseudomonas aeruginosa PAO1 can utilize various aromatic hydrocarbons as a carbon source. Among the three genes involved in the gentisate pathway of P. aeruginosa, the gene product of PA2473 belongs to the ζ-class glutathione S-transferase and is predicted to be a maleylpyruvate isomerase. In this study, we determined the crystal structure of maleylpyruvate isomerase from Pseudomonas aeruginosa PAO1 (PaMPI) at a resolution of 1.8â¯Å. PaMPI functions as a dimer and shows the glutathione S-transferase fold. The structure comparison with other glutathione S-transferase structures enabled us to predict the glutathione cofactor binding site and suggests that PaMPI has differences in residues that make up the putative substrate binding site. Biochemical study of PaMPI showed that the protein has an MPI activity. Interestingly, unlike the reported glutathione S-transferases so far, the purified PaMPI showed isomerase activity without the addition of the reduced glutathione, although the protein showed much higher activity when the glutathione cofactor was added to the reaction mixture. Taken together, our studies reveal that the gene product of PA2473 functions as a maleylpyruvate isomerase and might be involved in the gentisate pathway.
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Pseudomonas aeruginosa/enzimologia , cis-trans-Isomerases/química , Sítios de Ligação , Cristalografia por Raios X , Gentisatos/metabolismo , Glutationa/metabolismo , Humanos , Modelos Moleculares , Conformação Proteica , Multimerização Proteica , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/química , Pseudomonas aeruginosa/metabolismo , Especificidade por Substrato , cis-trans-Isomerases/metabolismoRESUMO
Angiogenesis must be precisely controlled because uncontrolled angiogenesis is involved in aggravation of disease symptoms. Vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR-2) signaling is a key pathway leading to angiogenic responses in vascular endothelial cells (ECs). Therefore, targeting VEGF/VEGFR-2 signaling may be effective at modulating angiogenesis to alleviate various disease symptoms. Oleanolic acid was verified as a VEGFR-2 binding chemical from anticancer herbs with similar binding affinity as a reference drug in the Protein Data Bank (PDB) entry 3CJG of model A coordination. Oleanolic acid effectively inhibited VEGF-induced VEGFR-2 activation and angiogenesis in HU-VECs without cytotoxicity. We also verified that oleanolic acid inhibits in vivo angiogenesis during the development and the course of the retinopathy of prematurity (ROP) model in the mouse retina. Taken together, our results suggest a potential therapeutic benefit of oleanolic acid for inhibiting angiogenesis in proangiogenic diseases, including retinopathy.
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Inibidores da Angiogênese/farmacologia , Ácido Oleanólico/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Fisiológica/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Neovascularização Retiniana/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
Streptomyces coelicolor A3 contains Sc5140, a gene coding for poorly understood bacterial LOG-like protein. In this study, we determined the crystal structure of Sc5140 and found it resembles the overall structure of other type-II LOGs. In addition, Sc5140 exhibited phosphoribohydrolase activity against adenosine monophosphate (AMP), indicating that it had the same function as known type-II LOGs. Based on these results, we designated Sc5140 as ScLOGII. We performed docking calculations of AMP into the ScLOGII structure, which suggested the mode of binding for type-II LOG with their AMP substrate. The ScLOGII structure uniquely exhibited a long tail-like structure at the N-terminus that was involved in hexamerization of the protein; the disordered N-terminal region (DNR). Truncation of DNR in ScLOGII negatively affected both the phosphoribohydrolase activity and the oligomerization of the protein, suggesting that this region functioned in enzyme stabilization. However, results from truncation experiments using ScLOGII and CgLOGII, a type-II LOG homologue from Corynebacterium glutamicum, were quite different, leaving uncertainty regarding the general functions of DNR in type-II LOGs. Overall, the current structural work may help in understand the significance of type-II LOG protein at the molecular level.
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Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Streptomyces coelicolor/metabolismo , Sequência de Aminoácidos , Domínio Catalítico , Cristalografia por Raios X , Modelos Moleculares , Homologia Estrutural de ProteínaRESUMO
Plastics, including poly(ethylene terephthalate) (PET), possess many desirable characteristics and thus are widely used in daily life. However, non-biodegradability, once thought to be an advantage offered by plastics, is causing major environmental problem. Recently, a PET-degrading bacterium, Ideonella sakaiensis, was identified and suggested for possible use in degradation and/or recycling of PET. However, the molecular mechanism of PET degradation is not known. Here we report the crystal structure of I. sakaiensis PETase (IsPETase) at 1.5 Å resolution. IsPETase has a Ser-His-Asp catalytic triad at its active site and contains an optimal substrate binding site to accommodate four monohydroxyethyl terephthalate (MHET) moieties of PET. Based on structural and site-directed mutagenesis experiments, the detailed process of PET degradation into MHET, terephthalic acid, and ethylene glycol is suggested. Moreover, other PETase candidates potentially having high PET-degrading activities are suggested based on phylogenetic tree analysis of 69 PETase-like proteins.
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Proteínas de Bactérias/química , Burkholderiales/enzimologia , Poluentes Ambientais/química , Hidrolases/química , Polietilenotereftalatos/química , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Burkholderiales/química , Domínio Catalítico , Clonagem Molecular , Cristalografia por Raios X , Poluentes Ambientais/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Etilenoglicol/química , Etilenoglicol/metabolismo , Expressão Gênica , Hidrolases/genética , Hidrolases/metabolismo , Cinética , Simulação de Acoplamento Molecular , Ácidos Ftálicos/química , Ácidos Ftálicos/metabolismo , Polietilenotereftalatos/metabolismo , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , TermodinâmicaRESUMO
OBJECTIVES: The aim of this study was to investigate the prognostic implication of functional incomplete revascularization (IR) and residual functional SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score (rFSS) in comparison with 3-vessel fractional flow reserve (FFR) and residual SYNTAX score. BACKGROUND: IR is associated with poor clinical outcomes in patients who underwent percutaneous coronary intervention. METHODS: A total of 385 patients who underwent 3-vessel FFR measurement after stent implantation were included in this study. The rFSS was defined as residual SYNTAX score measured only in vessels with FFR ≤0.8. The study population was divided into the functional IR group (rFSS ≥1) and the functional complete revascularization (CR) group (rFSS = 0). The primary outcome was major adverse cardiac events (MACEs; a composite of cardiac death, myocardial infarction, and ischemia-driven revascularization) at 2 years. RESULTS: Functional CR was achieved in 283 patients (73.5%). At 2-year follow-up, the functional IR group showed a significantly higher risk for MACEs (functional IR vs. CR, 14.6% vs. 4.2%; hazard ratio: 4.09; 95% confidence interval: 1.82 to 9.21; p < 0.001) than the functional CR group. In a multivariate-adjusted model, functional IR was an independent predictor of MACEs (adjusted hazard ratio: 4.17; 95% confidence interval: 1.85 to 9.44; p < 0.001). The rFSS showed a significant association with estimated 2-year MACE rate (hazard ratio: 1.09 per 1-U increase; 95% confidence interval: 1.02 to 1.17; p = 0.018). When added to clinical risk factors, rFSS showed the highest integrated discrimination improvement value for MACEs (3.5%; p = 0.002) among 3-vessel FFR, residual SYNTAX score, and rFSS. CONCLUSIONS: Patients with functional IR showed significantly higher rate of 2-year MACEs than those with functional CR. A combined anatomic and physiological scoring system (rFSS) after stent implantation better discriminated the risk for adverse events than anatomic or physiological assessment alone. (Clinical Implication of 3-Vessel Fractional Flow Reserve [FFR]; NCT01621438).
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Angiografia Coronária , Doença da Artéria Coronariana/cirurgia , Estenose Coronária/cirurgia , Intervenção Coronária Percutânea/efeitos adversos , Complicações Pós-Operatórias/diagnóstico por imagem , Idoso , Cateterismo Cardíaco , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/mortalidade , Doença da Artéria Coronariana/fisiopatologia , Estenose Coronária/diagnóstico por imagem , Estenose Coronária/mortalidade , Estenose Coronária/fisiopatologia , Feminino , Reserva Fracionada de Fluxo Miocárdico , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/instrumentação , Intervenção Coronária Percutânea/mortalidade , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/fisiopatologia , Valor Preditivo dos Testes , Estudos Prospectivos , Recuperação de Função Fisiológica , República da Coreia , Medição de Risco , Fatores de Risco , Stents , Fatores de Tempo , Resultado do TratamentoRESUMO
Pericytes (PCs) are crucial in maintaining the quiescence of endothelial cells (ECs) and the integrity of EC tight junctions. Especially in diabetic retinopathy (DR), PC loss is one of the early pathologic changes in capillaries of diabetic retinas. Thus, preventing PC loss is beneficial for attenuating vision impairment in patients with DR. Although many studies have revealed the mechanism of PC loss in retinas, little is known about the mechanisms that increase PC survival. We focused on the effect of ß-adrenergic receptor agonists (ß-agonists) on PC loss in diabetic retinas. In this study, ß-agonists increased the cell viability of PCs by increasing PC survival and proliferation. Mechanistically, ß-agonist-induced protein kinase B activation in PCs reduced PC apoptosis in response to various stimuli. ß2-agonists more potently increased PC survival than ß1-agonists. ß2-Agonist reduced vascular leakage and PC loss in retinas of mice with streptozotocin-induced diabetes. In cocultures of PCs and ECs, ß2-agonists restored the altered permeability and ZO-1 expression in ECs induced by PC loss. We concluded that ß-agonists, especially ß2-agonists, increase PC survival, thereby preventing diabetes-induced PC loss in retinas. These results provide a potential therapeutic benefit of ß-agonists for preventing PC loss in DR.-Yun, J.-H., Jeong, H.-S., Kim, K.-J., Han, M. H., Lee, E. H., Lee, K., Cho, C.-H. ß-Adrenergic receptor agonists attenuate pericyte loss in diabetic retinas through Akt activation.
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Agonistas de Receptores Adrenérgicos beta 2/farmacologia , Proliferação de Células/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Retinopatia Diabética/tratamento farmacológico , Pericitos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Retina/metabolismo , Animais , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Retinopatia Diabética/metabolismo , Retinopatia Diabética/patologia , Ativação Enzimática/efeitos dos fármacos , Humanos , Masculino , Camundongos , Pericitos/patologia , Retina/patologia , Proteína da Zônula de Oclusão-1/biossínteseRESUMO
Cystathionine γ-synthase (MetB) condenses O-acetyl-l-homoserine (OAHS) or O-succinyl-l-homoserine (OSHS) with cysteine to produce cystathionine. To investigate the molecular mechanisms and substrate specificity of MetB from Corynebacterium glutamicum (CgMetB), we determined its crystal structure at 1.5 Å resolution. The pyridoxal phosphate cofactor is covalently bound to Lys204 via a Schiff base linkage in the deep cavity. Superposition with the structure of MetB from Nicotiana tabacum in complex with its inhibitor dl-(E)-2-amino-5-phosphono-3-pentenoic acid revealed that Thr347 from the ß10-ß11 connecting loop, located at the entrance of the active site, is speculated to be a main contributor for stabilization of the acetyl group of OAHS. Moreover, on the basis of structural comparison of CgMetB with EcMetB utilizing OSHS as a main substrate, we propose that the conformation of the ß10-ß11 connecting loops determines the size and shape of the acetyl- or succinyl-group binding site and ultimately determines the substrate specificity of MetBs toward OAHS or OSHS.