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1.
Nat Struct Mol Biol ; 30(11): 1695-1706, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37770719

RESUMO

Defects in plasma membrane repair can lead to muscle and heart diseases in humans. Tripartite motif-containing protein (TRIM)72 (mitsugumin 53; MG53) has been determined to rapidly nucleate vesicles at the site of membrane damage, but the underlying molecular mechanisms remain poorly understood. Here we present the structure of Mus musculus TRIM72, a complete model of a TRIM E3 ubiquitin ligase. We demonstrated that the interaction between TRIM72 and phosphatidylserine-enriched membranes is necessary for its oligomeric assembly and ubiquitination activity. Using cryogenic electron tomography and subtomogram averaging, we elucidated a higher-order model of TRIM72 assembly on the phospholipid bilayer. Combining structural and biochemical techniques, we developed a working molecular model of TRIM72, providing insights into the regulation of RING-type E3 ligases through the cooperation of multiple domains in higher-order assemblies. Our findings establish a fundamental basis for the study of TRIM E3 ligases and have therapeutic implications for diseases associated with membrane repair.


Assuntos
Cardiopatias , Ubiquitina-Proteína Ligases , Camundongos , Humanos , Animais , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Proteínas com Motivo Tripartido/química , Proteínas com Motivo Tripartido/genética , Proteínas com Motivo Tripartido/metabolismo , Modelos Moleculares , Proteínas de Membrana/metabolismo
2.
Biochem Biophys Res Commun ; 582: 86-92, 2021 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-34695755

RESUMO

The cellular glucose level has to be tightly regulated by a variety of cellular processes. One of them is the degradation of gluconeogenic enzymes such as Fbp1, Icl1, Mdh2, and Pck1 by GID (glucose-induced degradation deficient) E3 ubiquitin ligase. The Gid4 component of the GID ligase complex is responsible for recognizing the N-terminal proline residue of the target substrates under normal conditions. However, an alternative N-recognin Gid10 controls the degradation process under stressed conditions. Although Gid10 shares a high sequence similarity with Gid4, their substrate specificities are quite different. Here, we report the structure of Gid10 from Saccharomyces cerevisiae in complex with Pro/N-degron, Pro-Tyr-Ile-Thr, which is almost identical to the sequence of the natural substrate Art2. Although Gid10 shares many structural features with the Gid4 protein from yeast and humans, the current structure explains the unique structural difference for the preference of bulky hydrophobic residue at the second position of Pro/N-degron. Therefore, this study provides a fundamental basis for understanding of the structural diversity and substrate specificity of recognition components in the GID E3 ligase complex involved in the Pro/N-degron pathway.


Assuntos
Oligopeptídeos/química , Proteínas de Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/química , Ubiquitina-Proteína Ligases/química , Proteínas de Transporte Vesicular/química , Sequência de Aminoácidos , Sítios de Ligação , Clonagem Molecular , Cristalografia por Raios X , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Modelos Moleculares , Oligopeptídeos/metabolismo , Prolina/química , Prolina/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Proteólise , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/enzimologia , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo
3.
EMBO Rep ; 22(6): e51323, 2021 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-33938112

RESUMO

In eukaryotic cells, mitochondria are closely tethered to the endoplasmic reticulum (ER) at sites called mitochondria-associated ER membranes (MAMs). Ca2+ ion and phospholipid transfer occurs at MAMs to support diverse cellular functions. Unlike those in yeast, the protein complexes involved in phospholipid transfer at MAMs in humans have not been identified. Here, we determine the crystal structure of the tetratricopeptide repeat domain of PTPIP51 (PTPIP51_TPR), a mitochondrial protein that interacts with the ER-anchored VAPB protein at MAMs. The structure of PTPIP51_TPR shows an archetypal TPR fold, and an electron density map corresponding to an unidentified lipid-like molecule probably derived from the protein expression host is found in the structure. We reveal functions of PTPIP51 in phospholipid binding/transfer, particularly of phosphatidic acid, in vitro. Depletion of PTPIP51 in cells reduces the mitochondrial cardiolipin level. Additionally, we confirm that the PTPIP51-VAPB interaction is mediated by the FFAT-like motif of PTPIP51 and the MSP domain of VAPB. Our findings suggest that PTPIP51 is a phospholipid transfer protein with a MAM-tethering function.


Assuntos
Cálcio , Fosfolipídeos , Cálcio/metabolismo , Retículo Endoplasmático/metabolismo , Humanos , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Fosfolipídeos/metabolismo , Proteínas Tirosina Fosfatases
4.
Sci Rep ; 9(1): 16316, 2019 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-31705139

RESUMO

The hydroxymethylation of cytosine bases plays a vital role in the phage DNA protection system inside the host Escherichia coli. This modification is known to be catalyzed by the dCMP hydroxymethylase from bacteriophage T4 (T4dCH); structural information on the complexes with the substrate, dCMP and the co-factor, tetrahydrofolate is currently available. However, the detailed mechanism has not been understood clearly owing to a lack of structure in the complex with a reaction intermediate. We have applied the X-ray free electron laser (XFEL) technique to determine a high-resolution structure of a T4dCH D179N active site mutant. The XFEL structure was determined at room temperature and exhibited several unique features in comparison with previously determined structures. Unexpectedly, we observed a bulky electron density at the active site of the mutant that originated from the physiological host (i.e., E. coli). Mass-spectrometric analysis and a cautious interpretation of an electron density map indicated that it was a dTMP molecule. The bound dTMP mimicked the methylene intermediate from dCMP to 5'-hydroxymethy-dCMP, and a critical water molecule for the final hydroxylation was convincingly identified. Therefore, this study provides information that contributes to the understanding of hydroxymethylation.


Assuntos
Bacteriófago T4/enzimologia , Elétrons , Hidroximetil e Formil Transferases/química , Hidroximetil e Formil Transferases/genética , Lasers , Mutação , Timidina Monofosfato/metabolismo , Cristalografia por Raios X , Hidroximetil e Formil Transferases/metabolismo , Modelos Moleculares , Conformação Proteica , Água/química
5.
IUCrJ ; 6(Pt 2): 206-217, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30867918

RESUMO

To protect viral DNA against the host bacterial restriction system, bacterio-phages utilize a special modification system - hydroxymethylation - in which dCMP hydroxymethylase (dCH) converts dCMP to 5-hydroxymethyl-dCMP (5hm-dCMP) using N5,N10-methylenetetrahydrofolate as a cofactor. Despite shared similarity with thymidylate synthase (TS), dCH catalyzes hydroxylation through an exocyclic methylene intermediate during the last step, which is different from the hydride transfer that occurs with TS. In contrast to the extensively studied TS, the hydroxymethylation mechanism of a cytosine base is not well understood due to the lack of a ternary complex structure of dCH in the presence of both its substrate and cofactor. This paper reports the crystal structure of the ternary complex of dCH from bacteriophage T4 (T4dCH) with dCMP and tetrahydrofolate at 1.9 Šresolution. The authors found key residues of T4dCH for accommodating the cofactor without a C-terminal tail, an optimized network of ordered water molecules and a hydrophobic gating mechanism for cofactor regulation. In combination with biochemical data on structure-based mutants, key residues within T4dCH and a substrate water molecule for hydroxymethylation were identified. Based on these results, a complete enzyme mechanism of dCH and signature residues that can identify dCH enzymes within the TS family have been proposed. These findings provide a fundamental basis for understanding the pyrimidine modification system.

6.
J Immunol ; 201(9): 2832-2841, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30275047

RESUMO

In addition to essential roles in protein synthesis, lysyl-tRNA synthetase (KRS) is secreted to trigger a proinflammatory function that induces macrophage activation and TNF-α secretion. KRS has been associated with autoimmune diseases such as polymyositis and dermatomyositis. In this study, we investigated the immunomodulatory effects of KRS on bone marrow-derived dendritic cells (DCs) of C57BL/6 mice and subsequent polarization of Th cells and analyzed the underlying mechanisms. KRS-treated DCs increased the expression of cell surface molecules and proinflammatory cytokines associated with DC maturation and activation. Especially, KRS treatment significantly increased production of IL-12, a Th1-polarizing cytokine, in DCs. KRS triggered the nuclear translocation of the NF-κB p65 subunit along with the degradation of IκB proteins and the phosphorylation of MAPKs in DCs. Additionally, JNK, p38, and ERK inhibitors markedly recovered the degradation of IκB proteins, suggesting the involvement of MAPKs as the upstream regulators of NF-κB in the KRS-induced DC maturation and activation. Importantly, KRS-treated DCs strongly increased the differentiation of Th1 cells when cocultured with CD4+ T cells. The addition of anti-IL-12-neutralizing Ab abolished the secretion of IFN-γ in the coculture, indicating that KRS induces Th1 cell response via DC-derived IL-12. Moreover, KRS enhanced the OVA-specific Th1 cell polarization in vivo following the adoptive transfer of OVA-pulsed DCs. Taken together, these results indicated that KRS effectively induced the maturation and activation of DCs through MAPKs/NF-κB-signaling pathways and favored DC-mediated Th1 cell response.


Assuntos
Diferenciação Celular/imunologia , Células Dendríticas/imunologia , Ativação Linfocitária/imunologia , Lisina-tRNA Ligase/imunologia , Células Th1/imunologia , Animais , Células Dendríticas/citologia , Células Dendríticas/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/imunologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Lisina-tRNA Ligase/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/imunologia , NF-kappa B/metabolismo , Transdução de Sinais/imunologia
7.
Circ Cardiovasc Interv ; 10(11)2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29146671

RESUMO

BACKGROUND: There are limited data on the frequency of and factors associated with quantitative coronary angiography (QCA)-defined longitudinal stent deformation (LSD) in various contemporary drug-eluting stents platforms. This study sought to evaluate the predictors of LSD and its long-term clinical implication. METHODS AND RESULTS: A patient-level pooled analysis was performed with 7350 lesions in 5871 patients treated with platinum-chromium-based everolimus-eluting stent (Promus Element), cobalt-chromium-based everolimus-eluting stent (Promus/Xience V), or cobalt-chromium-based zotarolimus-eluting stent (Endeavor Resolute). QCA was performed to analyze differences of stent length between immediate post-deployment and final post-procedure. Independent factors associated with LSD were identified. Clinical outcomes at 3 years were compared between those with and without QCA-based LSD. The frequency of QCA-based LSD was 1.12% (82 cases). Nine of these cases were angiographically overt. Left main or ostial lesion, bifurcation treatment with provisional side branch stenting or ballooning, additional downstream intervention of a distal lesion, intravascular ultrasound use, and adjunctive post-dilatation were independently associated with QCA-based LSD. The type of stent was not associated with QCA-based LSD. Rates of target lesion failure were nominally higher in lesions with QCA-based LSD than in those without (8.97% versus 5.88%; hazard ratio, 1.415; 95% confidence interval, 0.631-3.175; P=0.399). CONCLUSIONS: LSD is uncommon with contemporary drug-eluting stents, regardless of the type of stent platform. LSD is mainly associated with procedural factors, especially with additional downstream procedures which require the passage of devices through the stent. Careful manipulation of poststent imaging or procedural devices is required to prevent LSD. More data are needed to clarify the impact of LSD on clinical events.


Assuntos
Doença da Artéria Coronariana/terapia , Stents Farmacológicos , Intervenção Coronária Percutânea/instrumentação , Adulto , Idoso , Idoso de 80 Anos ou mais , Fármacos Cardiovasculares/administração & dosagem , Ligas de Cromo , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Bases de Dados Factuais , Everolimo/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/efeitos adversos , Platina , Desenho de Prótese , Falha de Prótese , República da Coreia , Fatores de Risco , Sirolimo/administração & dosagem , Sirolimo/análogos & derivados , Fatores de Tempo , Resultado do Tratamento , Ultrassonografia de Intervenção
8.
Sci Rep ; 7: 43318, 2017 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-28266564

RESUMO

The coiled-coil (CC) domain is a very important structural unit of proteins that plays critical roles in various biological functions. The major oligomeric state of CCs is a dimer, which can be either parallel or antiparallel. The orientation of each α-helix in a CC domain is critical for the molecular function of CC-containing proteins, but cannot be determined easily by sequence-based prediction. We developed a biochemical method for assessing differences between parallel and antiparallel CC homodimers and named it ACCORD (Assessment tool for homodimeric Coiled-Coil ORientation Decision). To validate this technique, we applied it to 15 different CC proteins with known structures, and the ACCORD results identified these proteins well, especially with long CCs. Furthermore, ACCORD was able to accurately determine the orientation of a CC domain of unknown directionality that was subsequently confirmed by X-ray crystallography and small angle X-ray scattering. Thus, ACCORD can be used as a tool to determine CC directionality to supplement the results of in silico prediction.

9.
Biochim Biophys Acta ; 1854(5): 356-64, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25641559

RESUMO

Spinocerebellar ataxia type 1 (SCA1), an autosomal-dominant neurodegenerative disorder, is caused by expansion of the polyglutamine tract within ataxin-1 (ATXN1). The AXH domain of ATXN1 can mediate neurodegeneration through its interaction with other proteins. We have previously showed that the ubiquitin-conjugating enzyme UbcH6 modulates the transcriptional repression activity of ATXN1 through ubiquitylation. In the present study, we sought to identify sites in the AXH domain that are ubiquitylated by UbcH6. Systematic replacement of each lysine residue in the AXH domain revealed that the lysine at 589 (K589) of ATXN1 is essential for its ubiquitylation by UbcH6. Mass spectrometry studies further confirmed the ubiquitylation site. Interestingly, protein aggregation was significantly enhanced in mutant AXH K589R, implying that the aggregation is strongly associated with the level of ATXN1 expression. Our study may suggest a therapeutic potential of UbcH6 in the treatment of SCA1.


Assuntos
Lisina , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/química , Proteínas Nucleares/metabolismo , Ubiquitinação , Sequência de Aminoácidos , Ataxina-1 , Ataxinas , Sítios de Ligação/genética , Células HEK293 , Humanos , Lisina/química , Lisina/genética , Modelos Moleculares , Mutagênese Sítio-Dirigida , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Agregados Proteicos , Ligação Proteica , Estrutura Terciária de Proteína/genética , Enzimas de Conjugação de Ubiquitina/metabolismo , Ubiquitinação/genética
10.
Acta Crystallogr F Struct Biol Commun ; 70(Pt 9): 1252-5, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25195903

RESUMO

Ski7 (superkiller protein 7) plays a critical role in the mRNA surveillance pathway. The C-terminal fragment of Ski7 (residues 520-747) from Saccharomyces cerevisiae was heterologously expressed in Escherichia coli and purified to homogeneity. It was successfully crystallized and preliminary X-ray data were collected to 2.0 Šresolution using synchrotron radiation. The crystal belonged to a trigonal space group, either P3121 or P3221, with unit-cell parameters a = b = 73.5, c = 83.6 Å. The asymmetric unit contains one molecule of the C-terminal fragment of Ski7 with a corresponding crystal volume per protein mass (VM) of 2.61 Å(3) Da(-1) and a solvent content of 52.8% by volume. The merging R factor is 6.6%. Structure determination by MAD phasing is under way.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/química , Cristalografia por Raios X/métodos , Fragmentos de Peptídeos/química , Proteínas de Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/química , Sequência de Bases , Cristalização , Primers do DNA , Eletroforese em Gel de Poliacrilamida , Reação em Cadeia da Polimerase , Conformação Proteica
11.
J Struct Biol ; 183(1): 40-6, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23664870

RESUMO

Cystathionine ß-synthase (CBS) domains are small intracellular modules that can act as binding domains for adenosine derivatives, and they may regulate the activity of associated enzymes or other functional domains. Among these, the single CBS domain-containing proteins, CBSXs, from Arabidopsis thaliana, have recently been identified as redox regulators of the thioredoxin system. Here, the crystal structure of CBSX2 in complex with adenosine monophosphate (AMP) is reported at 2.2Å resolution. The structure of dimeric CBSX2 with bound-AMP is shown to be approximately flat, which is in stark contrast to the bent form of apo-CBSXs. This conformational change in quaternary structure is triggered by a local structural change of the unique α5 helix, and by moving each loop P into an open conformation to accommodate incoming ligands. Furthermore, subtle rearrangement of the dimer interface triggers movement of all subunits, and consequently, the bent structure of the CBSX2 dimer becomes a flat structure. This reshaping of the structure upon complex formation with adenosine-containing ligand provides evidence that ligand-induced conformational reorganization of antiparallel CBS domains is an important regulatory mechanism.


Assuntos
Monofosfato de Adenosina/química , Proteínas de Arabidopsis/química , Cistationina beta-Sintase/química , Sítios de Ligação , Cristalografia por Raios X , Dimerização , Modelos Moleculares , Estrutura Terciária de Proteína
12.
Biochem Biophys Res Commun ; 430(1): 265-71, 2013 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-23159611

RESUMO

The single cystathionine ß-synthase (CBS) pair proteins from Arabidopsis thaliana have been identified as being a redox regulator of the thioredoxin (Trx) system. CBSX1 and CBSX2, which are two of the six Arabidopsis cystathione ß-synthase domain-containing proteins that contain only a single CBS pair, have close sequence similarity. Recently, the crystal structure of CBSX2 was determined and a significant portion of the internal region was disordered. In this study, crystal structures of full-length CBSX1 and the internal loop deleted (Δloop) form are reported at resolutions of 2.4 and 2.2Å, respectively. The structures of CBSX1 show that they form anti-parallel dimers along their central twofold axis and have a unique ∼155° bend along the side. This is different from the angle of CBSX2, which is suggestive of the flexible nature of the relative angle between the monomers. The biochemical data that were obtained using the deletion as well as point mutants of CBSX1 confirmed the importance of AMP-ligand binding in terms of enhancing Trx activity.


Assuntos
Monofosfato de Adenosina/química , Proteínas de Arabidopsis/química , Arabidopsis/enzimologia , Cistationina beta-Sintase/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Proteínas de Arabidopsis/genética , Sítios de Ligação , Cristalografia por Raios X , Cistationina beta-Sintase/genética , Dados de Sequência Molecular , Mutação Puntual , Conformação Proteica , Multimerização Proteica , Deleção de Sequência
13.
Korean Circ J ; 42(9): 595-9, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23091503

RESUMO

BACKGROUND AND OBJECTIVES: Statin prevents atherosclerotic progression and helps to stabilize the plaque. According to a recent study, statin reduces inflammation in blood vessels. However, it has not been demonstrated to have any anti-inflammation reaction in patients who have been diagnosed as having a triple-vessel coronary artery disease (CAD). SUBJECTS AND METHODS: This study included a total of thirty (30) patients who had been diagnosed by coronary angiogram as having a triple-vessel CAD. Patients who already had been taking statin were given doubled dosage. An interview, physical examination and blood test were performed at the beginning of this study and three months later. RESULTS: After doubling the dose of statin, there was no statistically significant decrease in total cholesterol, low density lipoprotein-cholesterol, (increase in) high density lipoprotein-cholesterol and triglyceride in the blood test. C-reactive protein (CRP), an acute phase reactant, significantly decreased from 0.34 mg/dL at the beginning of the study to 0.12 mg/dL at the end of study (p<0.01). The interleukin-6 concentration also significantly decreased from 8.55 pg/dL to 4.81 pg/dL (p<0.001). No major cardiovascular events occurred and the dosage regimen was not modified during the close observation period. There was no difference in the symptoms of angina pectoris, established by World Health Organization Angina Questionnaires, before and after the dose increase. Liver enzymes remained within normal range with no significant increase before and after conducting this study. CONCLUSION: Doubling the dose of statin alone significantly lowers pro-inflammatory cytokine concentration, which is closely related to the potential acute coronary syndrome, and CRP, a marker of vascular inflammation.

14.
Am J Cardiovasc Drugs ; 12(1): 35-47, 2012 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-22217192

RESUMO

BACKGROUND: Despite recommendations for more intensive treatment and the availability of several effective treatments, hypertension remains uncontrolled in many patients. OBJECTIVE: The aim of this study was to determine the dose-response relationship and assess the efficacy and safety of amlodipine or losartan monotherapy and amlodipine camsylate/losartan combination therapy in patients with essential hypertension. METHODS: This was an 8-week, randomized, double-blind, factorial design, phase II, multicenter study conducted in outpatient hospital clinics among adult patients aged 18-75 years with essential hypertension. At screening, patients received placebo for 2-4 weeks. Eligible patients (n=320) were randomized to one of eight treatment groups: amlodipine 5 mg or 10 mg, losartan 50 mg or 100 mg, amlodipine camsylate/losartan 5 mg/50 mg, 5 mg/100 mg, 10 mg/50 mg, or 10 mg/100 mg. MAIN OUTCOME MEASURES: The assumption of strict superiority was estimated using the mean change in sitting diastolic blood pressure (DBP) at 8 weeks. Safety was monitored through physical examinations, vital signs, laboratory test results, ECG, and adverse events. RESULTS: The reduction in DBP at 8 weeks was significantly greater in patients treated with the combination therapies compared with the respective monotherapies for all specified comparisons except amlodipine camsylate/losartan 10 mg/100 mg versus amlodipine 10 mg. The incidence of adverse events in the group of patients treated with the amlodipine camsylate/losartan 10 mg/50 mg combination tended to be higher than for any other group (27.9%, 12/43); however, the effect was not statistically significant. CONCLUSION: Combination amlodipine camsylate/losartan (5 mg/50 mg, 5 mg/100 mg and 10 mg/50 mg) resulted in significantly greater BP lowering compared with amlodipine or losartan monotherapy, and was determined to be generally safe and tolerable in patients with essential hypertension. CLINICAL TRIAL REGISTRATION: Registered at clinicaltrials.gov: NCT00942344.


Assuntos
Anlodipino/administração & dosagem , Anti-Hipertensivos/administração & dosagem , Hipertensão/tratamento farmacológico , Losartan/administração & dosagem , Adulto , Idoso , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Método Duplo-Cego , Combinação de Medicamentos , Quimioterapia Combinada , Feminino , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade
15.
Circulation ; 125(3): 505-13, 2012 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-22179532

RESUMO

BACKGROUND: The optimal duration of dual antiplatelet therapy (DAPT) after implantation of drug-eluting coronary stents remains undetermined. We aimed to test whether 6-month DAPT would be noninferior to 12-month DAPT after implantation of drug-eluting stents. METHODS AND RESULTS: We randomly assigned 1443 patients undergoing implantation of drug-eluting stents to receive 6- or 12-month DAPT (in a 1:1 ratio). The primary end point was a target vessel failure, defined as the composite of cardiac death, myocardial infarction, or ischemia-driven target vessel revascularization at 12 months. Rates of target vessel failure at 12 months were 4.8% in the 6-month DAPT group and 4.3% in the 12-month DAPT group (the upper limit of 1-sided 95% confidence interval, 2.4%; P=0.001 for noninferiority with a predefined noninferiority margin of 4.0%). Although stent thrombosis tended to occur more frequently in the 6-month DAPT group than in the 12-month group (0.9% versus 0.1%; hazard ratio, 6.02; 95% confidence interval, 0.72-49.96; P=0.10), the risk of death or myocardial infarction did not differ in the 2 groups (2.4% versus 1.9%; hazard ratio, 1.21; 95% confidence interval, 0.60-2.47; P=0.58). In the prespecified subgroup analysis, target vessel failure occurred more frequently in the 6-month DAPT group than in the 12-month group (hazard ratio, 3.16; 95% confidence interval, 1.42-7.03; P=0.005) among diabetic patients. CONCLUSIONS: Six-month DAPT did not increase the risk of target vessel failure at 12 months after implantation of drug-eluting stents compared with 12-month DAPT. However, the noninferiority margin was wide, and the study was underpowered for death or myocardial infarction. Our results need to be confirmed in larger trials. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00698607.


Assuntos
Aspirina/administração & dosagem , Doença das Coronárias/tratamento farmacológico , Reestenose Coronária/prevenção & controle , Stents Farmacológicos , Inibidores da Agregação Plaquetária/administração & dosagem , Ticlopidina/análogos & derivados , Idoso , Clopidogrel , Terapia Combinada , Doença das Coronárias/epidemiologia , Reestenose Coronária/epidemiologia , Quimioterapia Combinada , Feminino , Seguimentos , Hemorragia/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/prevenção & controle , Estudos Prospectivos , Fatores de Risco , Ticlopidina/administração & dosagem , Resultado do Tratamento
16.
Clin Ther ; 33(12): 1953-63, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22136978

RESUMO

BACKGROUND: The number of hypertensive patients achieving treatment targets is not ideal with therapies that engage a single mechanism of action, and combination therapies using different mechanisms of action can increase drug efficacy in a synergistic way. OBJECTIVE: This noninferiority study compared the clinical efficacy and safety profile of fixed-dose combination of amlodipine/losartan 5/50 mg and amlodipine 10 mg monotherapy in essential hypertensive patients who respond poorly to amlodipine 5 mg monotherapy. METHODS: This was a double-blind, multicenter, randomized trial of hypertensive patients (N = 185) aged ≥18 years taking amlodipine 5 mg during the run-in treatment period but failed to achieve sitting diastolic blood pressure (DBP) <90 mm Hg. After randomization into the amlodipine/losartan 5/50 mg fixed-dose combination group (n = 92) and the amlodipine 10 mg monotherapy group (n = 93), treatment was maintained without dose escalation for 8 weeks. The noninferiority margin was prespecified as 4 mm Hg after 8 weeks of treatment for the difference of the average change in DBP between treatments. The primary efficacy evaluation of noninferiority was tested using a confidence interval approach with a 97.5% 1-sided lower confidence limit using the average difference in DBP measured at baseline and 8 weeks. RESULTS: After 8 weeks, the DBP of both groups decreased from baseline by 8.9 (6.1) and 9.4 (7.5) mm Hg, respectively (difference = -0.5 [6.9] mm Hg, 95% CI: -2.5 to 1.5). Secondary end points of reductions in DBP after 4 weeks (-8.1 [6.7] vs -9.9 [7.3] mm Hg, difference = -1.8 mm Hg, 95% CI: -3.9 to 0.2) and sitting systolic blood pressure after 4 (-10.2 [11.8] vs -12.8 [10.2] mm Hg, difference = -2.6 mm Hg, 95% CI: -5.9 to 0.6) and 8 weeks (-12.2 [11.0] vs -13.4 [11.3] mm Hg, difference = -1.2 mmHg, 95% CI: -4.4 to 2.1) were comparable between the 2 treatment groups. There were 38 adverse events in 20 patients (21.7%) in the amlodipine/losartan 5/50 mg fixed-dose combination group and 31 in 24 patients (26.1%) in the amlodipine 10 mg monotherapy group; most were mild. There were 7 adverse events in 6 patients (6.5%) related to treatment in the fixed-dose combination group and 13 in 10 patients (10.9%) in the monotherapy group (P = 0.30). CONCLUSIONS: Fixed-dose combination amlodipine/losartan 5/50 mg was not inferior in terms of reductions in DBP after 8 weeks of treatment and had comparable safety profile to amlodipine 10 mg in patients who did not respond to amlodipine 5 mg monotherapy. ClinicalTrials.gov identifier: NCT00940667.


Assuntos
Anlodipino/administração & dosagem , Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Anti-Hipertensivos/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Bloqueadores dos Canais de Cálcio/administração & dosagem , Hipertensão/tratamento farmacológico , Losartan/administração & dosagem , Adulto , Anlodipino/efeitos adversos , Análise de Variância , Bloqueadores do Receptor Tipo 1 de Angiotensina II/efeitos adversos , Anti-Hipertensivos/efeitos adversos , Bloqueadores dos Canais de Cálcio/efeitos adversos , Distribuição de Qui-Quadrado , Relação Dose-Resposta a Droga , Método Duplo-Cego , Combinação de Medicamentos , Feminino , Humanos , Hipertensão/diagnóstico , Hipertensão/fisiopatologia , Losartan/efeitos adversos , Masculino , Pessoa de Meia-Idade , República da Coreia , Fatores de Tempo , Resultado do Tratamento
17.
J Am Coll Cardiol ; 58(18): 1844-54, 2011 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-22018294

RESUMO

OBJECTIVES: The goal of this study was to compare the angiographic outcomes of everolimus-eluting stents (EES) and sirolimus-eluting stents (SES) in a head-to-head manner. BACKGROUND: EES have been shown to be superior to paclitaxel-eluting stents in inhibiting late loss (LL) and clinical outcome. Whether EES may provide similar angiographic and clinical outcomes compared with SES is undetermined. METHODS: This was a prospective, randomized, open-label, multicenter trial to demonstrate the noninferiority of EES compared with SES in preventing LL at 9 months. A total of 1,443 patients undergoing percutaneous coronary intervention were randomized 3:1 to receive EES or SES. Routine follow-up angiography was recommended at 9 months. The primary endpoint was in-segment LL at 9 months, and major secondary endpoints included in-stent LL at 9 months, target lesion failure, cardiac death, nonfatal myocardial infarction, target lesion revascularization, and stent thrombosis at 12 months. Data were managed by an independent management center, and clinical events were adjudicated by an independent adjudication committee. RESULTS: Clinical follow-up was available in 1,428 patients and angiographic follow-up in 924 patients (1,215 lesions). The primary endpoint of the study (in-segment LL at 9 months) was 0.11 ± 0.38 mm and 0.06 ± 0.36 mm for EES and SES, respectively (p for noninferiority = 0.0382). The in-stent LL was also noninferior (EES 0.19 ± 0.35 mm; SES 0.15 ± 0.34 mm; p for noninferiority = 0.0121). The incidence of clinical endpoints was not statistically different between the 2 groups, including target lesion failure (3.75% vs. 3.05%; p = 0.53) and stent thrombosis (0.37% vs. 0.83%; p = 0.38). CONCLUSIONS: EES were noninferior to SES in inhibition of LL after stenting, which was corroborated by similar rates of clinical outcomes. (Efficacy of Xience/Promus Versus Cypher in Reducing Late Loss After Stenting [EXCELLENT]; NCT00698607).


Assuntos
Angioplastia Coronária com Balão , Stents Farmacológicos , Imunossupressores/administração & dosagem , Sirolimo/análogos & derivados , Sirolimo/administração & dosagem , Idoso , Angiografia Coronária , Doença das Coronárias/terapia , Reestenose Coronária/epidemiologia , Everolimo , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Falha de Prótese
18.
Korean Circ J ; 40(12): 632-8, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21267385

RESUMO

BACKGROUND AND OBJECTIVES: The aim of this study was to evaluate the efficacy of lacidipine in reducing blood pressure (BP) and to determine its effect on endothelial function in mild-to-moderate hypertensive patients with type 2 diabetes mellitus (DM). SUBJECTS AND METHODS: This was a prospective, multicenter, open-label, single-arm study, enrolling 290 patients with mild-to-moderate hypertension and type 2 DM. Patients were initially treated with 2 mg lacidipine orally once daily for 4 weeks, which was then increased as necessary every 4 weeks to a maximal dose of 6 mg daily. The primary endpoint was the mean change in systolic blood pressure (SBP) from baseline after 12 weeks of treatment. Secondary endpoints included mean changes in diastolic blood pressure (DBP), flow-mediated vasodilatation (FMD), and serum concentrations of biochemical markers such as high-sensitivity C-reactive protein (hs-CRP), monocyte chemo-attractant protein-1 (MCP-1), matrix metalloproteinase-9 (MMP-9), and plasminogen activator inhibitor-1 (PAI-1). RESULTS: Lacidipine treatment significantly reduced SBP by -13.4±13.0 mmHg (p<0.001) and DBP by -6.2±9.3 mmHg (p<0.001). Lacidipine treatment did not improve endothelial-dependent vasodilatation, despite significantly improved nitroglycerin-induced, endothelial-independent vasodilatation. MCP-1 levels significantly decreased from 283.66±110.08 pg/mL to 257.83±100.23 pg/mL (p<0.001); whereas there were no significant changes in the levels of hs-CRP, MMP-9, or PAI-1. CONCLUSION: Twelve weeks of treatment with lacidipine was effective and well tolerated in mild-to-moderate hypertensive patients with type 2 DM. In spite of inducing a significant reduction in MCP-1 levels, lacidipine did not improve endothelial function.

19.
Clin Ther ; 29(11): 2365-73, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18158077

RESUMO

BACKGROUND: Although previous studies have examined the efficacy of pitavastatin, its tolerability and effects on lipid concentrations have not been compared with those of atorvastatin in a multicenter, randomized study. OBJECTIVE: This trial compared the efficacy and tolerability of pitavastatin and atorvastatin in hypercholesterolemic Korean adults. METHODS: This 8-week, multicenter, randomized, open-label, dose-titration study was conducted at 18 clinical centers in Korea between May 2005 and February 2006. After a 4-week dietary lead-in period, patients with hypercholesterolemia were randomized to receive either pitavastatin 2 mg/d or atorvastatin 10 mg/d. Patients who had not reached the low-density lipoprotein cholesterol (LDL-C) goal by week 4 received a double dose of the assigned medication for an additional 4 weeks. Efficacy was evaluated in terms of achievement of the National Cholesterol Education Program Adult Treatment Panel III LDL-C goals and changes from baseline in other lipids and high-sensitivity C-reactive protein (hs-CRP). The tolerability profile was assessed by physical and electro-cardiographic examinations, laboratory tests, and recording adverse reactions at all visits. RESULTS: A total of 268 patients were randomized to treatment, and 222 (82.8%) completed the study (149 women, 73 men; mean age, 59 years; mean weight, 63.5 kg). At the end of the study, there was no significant difference between the pitavastatin and atorvastatin groups in the proportion of patients achieving the LDL-C goal (92.7% [102/110] vs 92.0% [103/112], respectively). In addition, there were no significant differences between groups in terms of the percent changes from baseline in LDL-C, total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), or hs-CRP. Twenty-six of 136 patients (19.1%) taking pitavastatin reported 35 treatment-emergent adverse reactions; 33 of 132 patients (25.0%) taking atorvastatin reported 39 treatment-emergent adverse reactions. Elevations in creatine kinase were observed in 6 patients (4.4%) in the pitavastatin group and 7 patients (5.3%) in the atorvastatin group. There were no serious adverse drug reactions in either group. CONCLUSIONS: In these adult Korean patients with hypercholesterolemia, pitavastatin and atorvastatin did not differ significantly in terms of the proportions of patients achieving the LDL-C goal; reductions in LDL-C, total cholesterol, and triglycerides; or increases in HDL-C. Both drugs were well tolerated.


Assuntos
Ácidos Heptanoicos/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipercolesterolemia/tratamento farmacológico , Pirróis/uso terapêutico , Quinolinas/uso terapêutico , Atorvastatina , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Feminino , Ácidos Heptanoicos/administração & dosagem , Ácidos Heptanoicos/efeitos adversos , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Hipercolesterolemia/sangue , Coreia (Geográfico) , Masculino , Pessoa de Meia-Idade , Pirróis/administração & dosagem , Pirróis/efeitos adversos , Quinolinas/administração & dosagem , Quinolinas/efeitos adversos , Triglicerídeos/sangue
20.
Korean J Intern Med ; 20(3): 243-6, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16295784

RESUMO

In the era before reperfusion therapy, ventricular septal rupture complicated 1approximate3% of acute myocardial infarctions (AMI) usually 3-5 days after onset. Studies have reported a positive correlation between the incidence of septal perforation and total occlusion of the coronary arteries. A 70-year old female patient was referred to the emergency room with the diagnosis of acute anterior myocardial infarction (MI) and recent cerebral infarction. The coronary angiogram showed a 90% stenosis at the mid-portion of the left anterior descending artery (LAD), and the lesion was successfully treated by percutaneous coronary intervention (PCI) with stent implantation. After PCI, the anterior wall motion improved on the follow-up echocardiogram. However, on the 20th hospital day, the patient condition deteriorated suddenly with pulmonary congestion. The echocardiography revealed a 1.3 cm ventricular septal defect at the apical septum with a left-to-right shunt. We report this rare case of delayed septal rupture in a patient with patent LAD after PCI and recovery of wall motion.


Assuntos
Septos Cardíacos/fisiopatologia , Ventrículos do Coração/fisiopatologia , Infarto do Miocárdio/complicações , Ruptura do Septo Ventricular/etiologia , Doença Aguda , Idoso , Angioplastia Coronária com Balão , Feminino , Humanos , Infarto do Miocárdio/cirurgia , Stents , Fatores de Tempo
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