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1.
Nat Commun ; 15(1): 2485, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38509117

RESUMO

Proteasome subunit hRpn13 is partially proteolyzed in certain cancer cell types to generate hRpn13Pru by degradation of its UCHL5/Uch37-binding DEUBAD domain and retention of an intact proteasome- and ubiquitin-binding Pru domain. By using structure-guided virtual screening, we identify an hRpn13 binder (XL44) and solve its structure ligated to hRpn13 Pru by integrated X-ray crystallography and NMR to reveal its targeting mechanism. Surprisingly, hRpn13Pru is depleted in myeloma cells following treatment with XL44. TMT-MS experiments reveal a select group of off-targets, including PCNA clamp-associated factor PCLAF and ribonucleoside-diphosphate reductase subunit M2 (RRM2), that are similarly depleted by XL44 treatment. XL44 induces hRpn13-dependent apoptosis and also restricts cell viability by a PCLAF-dependent mechanism. A KEN box, but not ubiquitination, is required for XL44-induced depletion of PCLAF. Here, we show that XL44 induces ubiquitin-dependent loss of hRpn13Pru and ubiquitin-independent loss of select KEN box containing proteins.


Assuntos
Glicoproteínas de Membrana , Complexo de Endopeptidases do Proteassoma , Complexo de Endopeptidases do Proteassoma/metabolismo , Glicoproteínas de Membrana/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Ubiquitina/metabolismo , Citoplasma/metabolismo , Fatores de Transcrição
2.
PLoS One ; 18(4): e0284147, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37053183

RESUMO

OBJECTIVES: One primary concern about receiving care at home is that survival might be shortened because the quality and quantity of treatment provided at home will be inferior to that given in the hospital. Although our previous study demonstrated a longer survival of those with home-based palliative care (PC), it lacked adjustment for some potential confounders including symptoms and treatments during the stay. We aimed to compare the survival times among advanced cancer patients receiving home-based and hospital-based PC with adjusting for symptoms and treatments. METHOD: We compared survival time of participants who enrolled two multicenter, prospective cohort studies of advanced cancer patients at 45-home-based PC services between July 2017 and December 2017, and at 23-hospital-based PC services between January 2017 and December 2017. We analyzed with stratification by the estimated survival of Days, Weeks, and Months, which were defined by modified Prognosis in Palliative care Study predictor models-A. We conducted a Cox regression analysis with adjusting for potential confounders including symptoms and treatments during the stay. RESULTS: A total of 2,998 patients were enrolled in both studies and 2,878 patients were analyzed; 988 patients receiving home-based PC and 1,890 receiving hospital-based PC. The survival time of patients receiving home-based PC was significantly longer than that of patients receiving hospital-based PC for the Days Prognosis (estimated median survival time: 10 days [95% CI 8.1-11.8] vs. 9 days [95% CI 8.3-10.4], p = 0.157), the Weeks prognosis (32 days [95% CI 28.9-35.4] vs. 22 days [95% CI 20.3-22.9], p < 0.001), and the Months Prognosis, (65 days [95% CI 58.2-73.2] vs. 32 days [95% CI 28.9-35.4], p < 0.001). CONCLUSION: In this cohort of advanced cancer patients with a Weeks or Months prognosis, those receiving home-based PC survived longer than those receiving hospital-based PC after adjusting for symptoms and treatments.


Assuntos
Neoplasias , Cuidados Paliativos , Humanos , Estudos Prospectivos , Neoplasias/terapia , Hospitais , Prognóstico , Estudos Retrospectivos
3.
Nat Commun ; 13(1): 7117, 2022 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-36402773

RESUMO

APOBEC3 proteins (A3s) are enzymes that catalyze the deamination of cytidine to uridine in single-stranded DNA (ssDNA) substrates, thus playing a key role in innate antiviral immunity. However, the APOBEC3 family has also been linked to many mutational signatures in cancer cells, which has led to an intense interest to develop inhibitors of A3's catalytic activity as therapeutics as well as tools to study A3's biochemistry, structure, and cellular function. Recent studies have shown that ssDNA containing 2'-deoxy-zebularine (dZ-ssDNA) is an inhibitor of A3s such as A3A, A3B, and A3G, although the atomic determinants of this activity have remained unknown. To fill this knowledge gap, we determined a 1.5 Å resolution structure of a dZ-ssDNA inhibitor bound to active A3G. The crystal structure revealed that the activated dZ-H2O mimics the transition state by coordinating the active site Zn2+ and engaging in additional stabilizing interactions, such as the one with the catalytic residue E259. Therefore, this structure allowed us to capture a snapshot of the A3's transition state and suggests that developing transition-state mimicking inhibitors may provide a new opportunity to design more targeted molecules for A3s in the future.


Assuntos
Citidina Desaminase , Oligonucleotídeos , Desaminase APOBEC-3G/química , Citidina Desaminase/genética , DNA de Cadeia Simples , Domínio Catalítico
4.
Genes (Basel) ; 13(10)2022 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-36292665

RESUMO

Thin basement membrane nephropathy (TBMN) is characterized by the observation of microhematuria and a thin glomerular basement membrane on kidney biopsy specimens. Its main cause is heterozygous mutations of COL4A3 or COL4A4, which also cause late-onset focal segmental glomerulosclerosis (FSGS) or autosomal dominant Alport syndrome (ADAS). Thirteen TBMN cases were analyzed using Sanger sequencing, multiplex ligation-dependent probe amplification (MLPA), and exome sequencing. Ten heterozygous variants were detected in COL4A3 or COL4A4 in nine patients via Sanger sequencing, three of which were novel variants. The diagnostic rate of "likely pathogenic" or "pathogenic" under the American College of Medical Genetics and Genomics guidelines was 53.8% (7 out of 13 patients). There were eight single nucleotide variants, seven of which were glycine substitutions in the collagenous domain, one of which was a splice-site single nucleotide variant, and two of which were deletion variants. One patient had digenic variants in COL4A3 and COL4A4. While MLPA analyses showed negative results, exome sequencing identified three heterozygous variants in causative genes of FSGS in four patients with no apparent variants on Sanger sequencing. Since patients with heterozygous mutations of COL4A3 or COL4A4 showed a wide spectrum of disease from TBMN to ADAS, careful follow-up will be necessary for these patients.


Assuntos
Glomerulosclerose Segmentar e Focal , Nefrite Hereditária , Humanos , Colágeno Tipo IV/genética , Glomerulosclerose Segmentar e Focal/genética , Glomerulosclerose Segmentar e Focal/patologia , Nefrite Hereditária/genética , Mutação , Membrana Basal/patologia , Glicina/genética , Nucleotídeos
5.
J Magn Reson ; 340: 107234, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35617919

RESUMO

T cells engineered to express artificial chimeric antigen receptors (CARs) that selectively target tumor-specific antigens or deleterious cell types offer transformative therapeutic possibilities. CARs contain an N-terminal extracellular antigen recognition domain, C-terminal intracellular signal transduction domains, and connecting hinge and transmembrane regions, each of which have been varied to optimize targeting and minimize toxicity. We find that a CD22-targeting CAR harboring a CD8α hinge (H) exhibits greater cytotoxicity against a low antigen density CD22+ leukemia as compared to an equivalent CAR with a CD28 H. We therefore studied the biophysical and dynamic properties of the CD8α H by nuclear magnetic resonance (NMR) spectroscopy. We find that a large region of the CD8α H undergoes dynamic chemical exchange between distinct and observable states. This exchanging region contains proline residues dispersed throughout the sequence that undergo cis-trans isomerization. Up to four signals of differing intensity are observed, with the most abundantly populated being intrinsically disordered and with all prolines in the trans isomerization state. The lesser populated states all contain cis prolines and evidence of local structural motifs. Altogether, our data suggest that the CD8α H lacks long-range structural order but has local structural motifs that transiently exchange with a dominant disordered state. We propose that structural plasticity and local structural motifs promoted by cis proline states within the CD8α H are important for relaying and amplifying antigen-binding effects to the transmembrane and signal transduction domains.


Assuntos
Prolina , Sequência de Aminoácidos , Isomerismo , Espectroscopia de Ressonância Magnética , Prolina/química
6.
Nat Commun ; 12(1): 7318, 2021 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-34916494

RESUMO

Proteasome substrate receptor hRpn13 is a promising anti-cancer target. By integrated in silico and biophysical screening, we identified a chemical scaffold that binds hRpn13 with non-covalent interactions that mimic the proteasome and a weak electrophile for Michael addition. hRpn13 Pru domain binds proteasomes and ubiquitin whereas its DEUBAD domain binds deubiquitinating enzyme UCHL5. NMR revealed lead compound XL5 to interdigitate into a hydrophobic pocket created by lateral movement of a Pru ß-hairpin with an exposed end for Proteolysis Targeting Chimeras (PROTACs). Implementing XL5-PROTACs as chemical probes identified a DEUBAD-lacking hRpn13 species (hRpn13Pru) present naturally with cell type-dependent abundance. XL5-PROTACs preferentially target hRpn13Pru, causing its ubiquitination. Gene-editing and rescue experiments established hRpn13 requirement for XL5-PROTAC-triggered apoptosis. These data establish hRpn13 as an anti-cancer target for multiple myeloma and introduce an hRpn13-targeting scaffold that can be optimized for preclinical trials against hRpn13Pru-producing cancer types.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Mieloma Múltiplo/metabolismo , Ubiquitinação , Apoptose , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Mieloma Múltiplo/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Fatores de Transcrição/metabolismo , Ativação Transcricional , Ubiquitina/metabolismo
7.
J Biol Chem ; 297(2): 100909, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34171358

RESUMO

The human cytidine deaminase family of APOBEC3s (A3s) plays critical roles in both innate immunity and the development of cancers. A3s comprise seven functionally overlapping but distinct members that can be exploited as nucleotide base editors for treating genetic diseases. Although overall structurally similar, A3s have vastly varying deamination activity and substrate preferences. Recent crystal structures of ssDNA-bound A3s together with experimental studies have provided some insights into distinct substrate specificities among the family members. However, the molecular interactions responsible for their distinct biological functions and how structure regulates substrate specificity are not clear. In this study, we identified the structural basis of substrate specificities in three catalytically active A3 domains whose crystal structures have been previously characterized: A3A, A3B- CTD, and A3G-CTD. Through molecular modeling and dynamic simulations, we found an interdependency between ssDNA substrate binding conformation and nucleotide sequence specificity. In addition to the U-shaped conformation seen in the crystal structure with the CTC0 motif, A3A can accommodate the CCC0 motif when ssDNA is in a more linear (L) conformation. A3B can also bind both U- and L-shaped ssDNA, unlike A3G, which can stably recognize only linear ssDNA. These varied conformations are stabilized by sequence-specific interactions with active site loops 1 and 7, which are highly variable among A3s. Our results explain the molecular basis of previously observed substrate specificities in A3s and have implications for designing A3-specific inhibitors for cancer therapy as well as engineering base-editing systems for gene therapy.


Assuntos
Desaminases APOBEC/química , Desaminases APOBEC/metabolismo , DNA de Cadeia Simples/química , Mutação , Neoplasias/patologia , Desaminases APOBEC/genética , Desaminases APOBEC/imunologia , Sequência de Aminoácidos , Domínio Catalítico , Cristalografia por Raios X , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/metabolismo , Humanos , Modelos Moleculares , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/metabolismo , Ligação Proteica , Especificidade por Substrato
8.
BMC Gastroenterol ; 21(1): 267, 2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34167461

RESUMO

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most frequent genetic kidney disease and polycystic liver disease is its major extrarenal manifestation, however biliary peritonitis due to a liver cyst rupture is extremely rare. CASE PRESENTATION: The patient was a 71-year-old Japanese woman who was diagnosed with ADPKD 3 years previously and developed right abdominal pain suddenly 1 month previously. As abdominal computed tomography (CT) showed a ruptured liver cyst in the right lobe, she was admitted to our hospital. Her symptoms improved with conservative management and she was discharged from the hospital after 1 week. Although she was asymptomatic for a while, she noticed abdominal distension and general malaise at 1 month after hospital discharge. Since abdominal CT showed massive ascites, she was admitted to our hospital again. A physical examination revealed abdominal distention without tenderness. Her serum creatinine, alkaline phosphatase, γ-glutamyl transpeptidase, total bilirubin, and CA19-9 were elevated. Abdominal paracentesis revealed amber transparent ascites and the bilirubin and CA19-9 concentrations were high. She was diagnosed with biliary peritonitis due to a ruptured liver cyst. Hemodialysis treatment was initiated with drainage of the ascites. The outflow of the ascites was no tendency to decrease and drip infusion cholangiography (DIC)-CT revealed a communication between the ruptured cyst and an intrahepatic bile duct. On day 31, she was transferred to a university hospital and abdominal surgery was performed. After removing the necrotic roof of the ruptured cyst on the right liver lobe, the orifice of the bile leakage was sutured. Cholecystectomy was performed and cholangiography showed no stones in the common bile duct. Abdominal CT one month after the operation showed no recurrence of ascites and she was discharged on day 49. Hemodialysis treatment was discontinued immediately after discharge because urine volume increased and her creatinine level decreased. There has been no recurrence of ascites since then. CONCLUSIONS: While rare, biliary peritonitis can occur in association with the rupture of a liver cyst in ADPKD patients due to communication between the cyst and the intrahepatic bile duct, and DIC-CT should be recommended when biliary cyst rupture is suspected.


Assuntos
Cistos , Peritonite , Rim Policístico Autossômico Dominante , Idoso , Ductos Biliares Intra-Hepáticos , Cistos/complicações , Cistos/diagnóstico por imagem , Cistos/cirurgia , Feminino , Humanos , Hepatopatias , Peritonite/etiologia , Rim Policístico Autossômico Dominante/complicações
9.
Curr Opin Struct Biol ; 67: 195-204, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33486429

RESUMO

APOBEC3 enzymes are key enzymes in our innate immune system regulating antiviral response in HIV and unfortunately adding diversity in cancer as they deaminate cytosine. Seven unique single and double domain APOBEC3s provide them with unique activity and specificity profiles for this deamination. Recent crystal and NMR structures of APOBEC3 complexes are unraveling the variety of epitopes involved in binding nucleic acids, including at the catalytic site, elsewhere on the catalytic domain and in the inactive N-terminal domain. The interplay between these diverse interactions is critical to uncovering the mechanisms by which APOBEC3s recognize and process their substrates.


Assuntos
Desaminases APOBEC , DNA , RNA , Desaminases APOBEC/metabolismo
10.
Circ J ; 84(11): 1912-1921, 2020 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-32981924

RESUMO

BACKGROUND: There is insufficient real-world data on the current status of Japanese patients with venous thromboembolism (VTE) or its treatment and prevention with rivaroxaban.Methods and Results:In this multicenter, prospective, observational study conducted in Japan, 1,039 patients with acute symptomatic/asymptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) with or without DVT prescribed rivaroxaban were enrolled at 152 institutions and observed for a median of 21.3 months. Mean age was 68.0±14.7 years, mean body weight was 60.3±14.1 kg, 59.0% were females, and 19.0% had active cancer. Incidences of recurrence or aggravation of symptomatic VTE (primary effectiveness outcome) and major bleeding (principal safety outcome) were 2.6% and 2.9% per patient-year, respectively. These outcomes did not differ between patients with DVT and those with PE (primary effectiveness outcome: 2.6% vs. 2.5% per patient-year, P=0.810; principal safety outcome: 3.5% vs. 2.4% per patient-year, P=0.394). The incidence of composite clinically relevant events, including recurrence or aggravation of symptomatic VTE, acute coronary syndrome, ischemic stroke, all-cause death, or major bleeding events, was 9.2% per patient-year. Multivariate analysis revealed that male sex, being underweight, having active cancer, chronic heart and lung disease, and previous stroke were independent determinants for composite clinically relevant events. CONCLUSIONS: In Japanese clinical practice, a single-drug approach with rivaroxaban was demonstrated to be a valuable treatment for a broad range of VTE patients.


Assuntos
Embolia Pulmonar , Rivaroxabana/uso terapêutico , Tromboembolia Venosa , Trombose Venosa , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes , Feminino , Hemorragia/induzido quimicamente , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Neoplasias/complicações , Neoplasias/tratamento farmacológico , Estudos Prospectivos , Tromboembolia Venosa/tratamento farmacológico , Trombose Venosa/tratamento farmacológico
11.
Heliyon ; 6(1): e03094, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31909264

RESUMO

A photovoltaic power generation system suitable for mobile applications was developed. A SiC integrated converter with the maximum power point tracking circuit provided the smallest photovoltaic inverter in ~200 W level. The SiC-based inverter exhibited a peak direct current (DC)-alternating current (AC) conversion efficiency higher than that of conventional Si inverters. A Li-ion laminated battery was mounted in the same housing as the inverter. The weight of entire system containing spherical Si solar cell panels was well below 6 kg. Continuous operation measurements of this system were carried out using four solar cell modules connected in parallel under irradiation by natural sunlight. The total inverter efficiencies under realistic operation conditions were slightly decreased compared with the DC-AC converter values because of loss by the maximum power point tracking device. Even under unstable weather conditions, the system provided power stability without ripples. The behaviors of the output powers of the solar cell, storage battery, and inverter modules were analyzed as a function of the solar radiation power density. The substantial efficiencies of the solar cell modules were dependent on the weather conditions and were approximately 10% on cloudy days. The present compact photovoltaic power generation system with SiC device and spherical Si solar cells is viable for sub kW-class inverter.

12.
Clin Exp Nephrol ; 24(4): 307-313, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31845065

RESUMO

BACKGROUND: Hyperuricemia is a known risk factor for end-stage renal disease. Although xanthine oxidase (XO) inhibitors are expected to protect the kidney function, evidence to this end is insufficient at present. METHODS: This study was a multi-center, open-labeled, randomized study conducted in Mie Prefecture in Japan. Patients were included if they were between 20 and 80 years old and had a serum uric acid (sUA) level ≥ 7.0 mg/dl with or without gout, estimated glomerular filtration rate (eGFR) of 15-60 ml/min/1.73 m2, and urinary protein creatinine ratio (uPCR) of 0.15-3.5 g/gCr. Patients were randomly assigned to a Topiroxostat or Febuxostat group, and the treatment target for the sUA level was < 6.0 mg/dl. The primary outcome was the change in the uPCR after 24 weeks. RESULTS: The change in the median uPCR after 24 weeks was not statistically significant after treatment in the Topiroxostat or Febuxostat group (0.05 g/gCr and - 0.04 g/gCr, respectively). However, the sUA levels decreased significantly in both groups (Topiroxostat group: 8.6 ± 1.1 at baseline to 6.0 ± 1.1 mg/dl at 24 weeks, Febuxostat group: 8.4 ± 1.1 mg/dl at baseline to 5.9 ± 1.3 mg/dl at 24 weeks). No significant change in the eGFR after 24 weeks was noted in either the Topiroxostat or Febuxostat group (- 0.04 ± 4.59 ml/min/1.73 m2 and 0.31 ± 4.70 ml/min/1.73 m2, respectively). CONCLUSIONS: In this study, XO inhibitors did not significantly reduce the uPCR in chronic kidney disease stage 3 and 4 patients with hyperuricemia.


Assuntos
Febuxostat/uso terapêutico , Hiperuricemia/tratamento farmacológico , Nitrilas/uso terapêutico , Piridinas/uso terapêutico , Insuficiência Renal Crônica/complicações , Xantina Oxidase/antagonistas & inibidores , Idoso , Creatinina/urina , Febuxostat/farmacologia , Feminino , Humanos , Hiperuricemia/complicações , Masculino , Pessoa de Meia-Idade , Nitrilas/farmacologia , Piridinas/farmacologia , Insuficiência Renal Crônica/urina
13.
J Chem Theory Comput ; 15(1): 637-647, 2019 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-30457868

RESUMO

APOBEC3 (A3) proteins, a family of human cytidine deaminases, protect the host from endogenous retro-elements and exogenous viral infections by introducing hypermutations. However, overexpressed A3s can modify genomic DNA to promote tumorigenesis, especially A3B. Despite their overall similarity, A3 proteins have distinct deamination activity. Recently determined A3 structures have revealed the molecular determinants of nucleotide specificity and DNA binding. However, for A3B, the structural basis for regulation of deamination activity and the role of active site loops in coordinating DNA had remained unknown. Using advanced molecular modeling followed by experimental mutational analysis and dynamics simulations, we investigated the molecular mechanism of DNA binding by A3B-CTD. We modeled fully native A3B-DNA structure, and we identified Arg211 in loop 1 as the gatekeeper coordinating DNA and critical residue for nucleotide specificity. We also identified a unique autoinhibited conformation in A3B-CTD that restricts access and binding of DNA to the active site. Our results reveal the structural basis for DNA binding and relatively lower catalytic activity of A3B and provide opportunities for rational design of specific inhibitors to benefit cancer therapeutics.


Assuntos
Citidina Desaminase/metabolismo , DNA de Cadeia Simples/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , Domínio Catalítico , Citidina Desaminase/química , Citidina Desaminase/genética , Humanos , Antígenos de Histocompatibilidade Menor/química , Antígenos de Histocompatibilidade Menor/genética , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica , Especificidade por Substrato
14.
Sci Rep ; 8(1): 7511, 2018 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-29760455

RESUMO

The APOBEC3 (A3) family of human cytidine deaminases is renowned for providing a first line of defense against many exogenous and endogenous retroviruses. However, the ability of these proteins to deaminate deoxycytidines in ssDNA makes A3s a double-edged sword. When overexpressed, A3s can mutate endogenous genomic DNA resulting in a variety of cancers. Although the sequence context for mutating DNA varies among A3s, the mechanism for substrate sequence specificity is not well understood. To characterize substrate specificity of A3A, a systematic approach was used to quantify the affinity for substrate as a function of sequence context, length, secondary structure, and solution pH. We identified the A3A ssDNA binding motif as (T/C)TC(A/G), which correlated with enzymatic activity. We also validated that A3A binds RNA in a sequence specific manner. A3A bound tighter to substrate binding motif within a hairpin loop compared to linear oligonucleotide, suggesting A3A affinity is modulated by substrate structure. Based on these findings and previously published A3A-ssDNA co-crystal structures, we propose a new model with intra-DNA interactions for the molecular mechanism underlying A3A sequence preference. Overall, the sequence and structural preferences identified for A3A leads to a new paradigm for identifying A3A's involvement in mutation of endogenous or exogenous DNA.


Assuntos
Citidina Desaminase/química , Citidina Desaminase/metabolismo , DNA de Cadeia Simples/química , DNA de Cadeia Simples/metabolismo , Proteínas/química , Proteínas/metabolismo , RNA/metabolismo , Motivos de Aminoácidos , Sítios de Ligação , DNA de Cadeia Simples/genética , Humanos , Concentração de Íons de Hidrogênio , Modelos Moleculares , Mutação , Conformação de Ácido Nucleico , Ligação Proteica , Conformação Proteica , RNA/química , Especificidade por Substrato
15.
Circ J ; 82(2): 586-595, 2018 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-29093429

RESUMO

BACKGROUND: The aim of this study was to assess the echocardiographic characteristics of chronic hemodialysis (HD) patients with end-stage renal disease (ESRD) in a multicenter prospective cohort study.Methods and Results:Three hundred and fifteen patients with ESRD (67.9±10.6 years, 47.6% male) on chronic HD for ≥1 year were examined on transthoracic echocardiography, including Doppler-derived aortic valve area (AVA) measurement. Only 11.5% and 3.4% of all patients had normal left ventricular (LV) geometry and normal LV filling pattern, respectively. The majority of patients had aortic and mitral valvular calcification, and approximately 50% of all 315 patients had aortic valve narrowing with AVA <2.0 cm2. Patients were divided into 3 groups according to AVA index tertile: group 1, highest tertile; group 2, middle tertile; and group 3, lowest tertile. Group 3 was older, had a greater cardiothoracic ratio on chest X-ray, higher plasma brain natriuretic peptide and total LV afterload, and lower stroke volume index than the other 2 groups. Age and intact parathyroid hormone (PTH) level were independently associated with low AVA index. CONCLUSIONS: Patients with ESRD on chronic HD have a high prevalence of cardiac structural and functional abnormalities including calcified aortic sclerosis. High age and PTH were associated with aortic valve narrowing in these patients.


Assuntos
Ecocardiografia/métodos , Cardiopatias Congênitas/diagnóstico por imagem , Falência Renal Crônica/complicações , Diálise Renal , Idoso , Estenose da Valva Aórtica , Calcinose , Humanos , Pessoa de Meia-Idade , Valva Mitral/patologia , Hormônio Paratireóideo/sangue , Estudos Prospectivos , Fatores de Risco , Função Ventricular Esquerda
16.
Nat Commun ; 8: 15024, 2017 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-28452355

RESUMO

Nucleic acid editing enzymes are essential components of the immune system that lethally mutate viral pathogens and somatically mutate immunoglobulins, and contribute to the diversification and lethality of cancers. Among these enzymes are the seven human APOBEC3 deoxycytidine deaminases, each with unique target sequence specificity and subcellular localization. While the enzymology and biological consequences have been extensively studied, the mechanism by which APOBEC3s recognize and edit DNA remains elusive. Here we present the crystal structure of a complex of a cytidine deaminase with ssDNA bound in the active site at 2.2 Å. This structure not only visualizes the active site poised for catalysis of APOBEC3A, but pinpoints the residues that confer specificity towards CC/TC motifs. The APOBEC3A-ssDNA complex defines the 5'-3' directionality and subtle conformational changes that clench the ssDNA within the binding groove, revealing the architecture and mechanism of ssDNA recognition that is likely conserved among all polynucleotide deaminases, thereby opening the door for the design of mechanistic-based therapeutics.


Assuntos
Domínio Catalítico , Citidina Desaminase/química , Citidina/química , DNA de Cadeia Simples/química , Proteínas/química , Sequência de Aminoácidos , Cristalografia por Raios X , Citidina/metabolismo , Citidina Desaminase/genética , Citidina Desaminase/metabolismo , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/metabolismo , Desaminação , Humanos , Modelos Moleculares , Ligação Proteica , Domínios Proteicos , Estrutura Secundária de Proteína , Proteínas/genética , Proteínas/metabolismo , Homologia de Sequência de Aminoácidos , Especificidade por Substrato
17.
Retrovirology ; 14(1): 19, 2017 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-28302150

RESUMO

BACKGROUND: HIV-1 Vif interacts with the cellular core-binding factor ß (CBFß) and counteracts the protective roles of certain human APOBEC3 (A3) proteins by targeting them for proteasomal degradation. Previous studies have identified some amino acids important for Vif-CBFß interactions, and recently a co-crystal structure of a pentameric complex of HIV-1 Vif, CBFß, Cul5, EloB, and EloC was resolved. However, a comprehensive analysis of Vif-CBFß interactions that are important for Vif function has not been performed. RESULTS: Here, we carried out double-alanine scanning mutagenesis of the first 60 amino acids of Vif and determined their effects on interaction with CBFß and their ability to induce A3G degradation as well as rescue HIV-1 replication in the presence of A3G. We found that multiple Vif residues are involved in the extensive N-terminal Vif-CBFß interaction and that the 5WQVMIVW11 region of Vif is the major determinant. A minimum of three alanine substitutions are required to completely abrogate the Vif-CBFß interaction and Vif's ability to rescue HIV-1 infectivity in the presence of A3G. Mutational analysis of CBFß revealed that F68 and I55 residues are important and participate in a tripartite hydrophobic interaction with W5 of Vif to maintain a stable and functional Vif-CBFß complex. We also determined that CBFß amino acids 73WQGEQR78, which are not resolved in the structure of the pentameric complex, are not involved in interaction with HIV-1 Vif. CONCLUSIONS: Our results provide detailed insight into the Vif-CBFß interactions that are critical for Vif function and may contribute to the rational design of HIV-1 inhibitors that block Vif-mediated degradation of A3 proteins.


Assuntos
Subunidade beta de Fator de Ligação ao Core/metabolismo , HIV-1/fisiologia , Interações Hospedeiro-Patógeno , Mapeamento de Interação de Proteínas , Produtos do Gene vif do Vírus da Imunodeficiência Humana/metabolismo , Substituição de Aminoácidos , Subunidade beta de Fator de Ligação ao Core/genética , Análise Mutacional de DNA , Humanos , Mutagênese Sítio-Dirigida , Ligação Proteica , Produtos do Gene vif do Vírus da Imunodeficiência Humana/genética
18.
Case Rep Nephrol Dial ; 6(2): 96-100, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27722157

RESUMO

Renal failure and infectious disease are strongly associated with morbidity and mortality in patients with severe generalized recessive dystrophic epidermolysis bullosa (RDEB-sev gen). However, it is reportedly difficult to introduce hemodialysis with an arteriovenous fistula (AVF). We encountered a 32-year-old man with RDEB-sev gen in whom hemodialysis with a native AVF was introduced that favorably affected his long-term survival. This patient eventually died because of cachexia related to the recurrence of cutaneous squamous cell carcinoma 51 months after hemodialysis introduction. We believe that in this patient, the frequency of vascular access troubles related to infection or reduction of blood flow was probably low as a result of hemodialysis with his native AVF. Thus, it seems likely that patients with RDEB-sev gen with end stage kidney disease who are on hemodialysis can be successfully managed with a native AVF.

19.
Circ J ; 80(3): 712-21, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26841805

RESUMO

BACKGROUND: Despite mounting evidence of increased cardiovascular events in patients with peripheral arterial disease (PAD), the overall incidence of cardiovascular events in PAD patients has not been fully clarified in Japan. The prospective Surveillance of cardiovascular Events in Antiplatelet-treated arterioSclerosis Obliterans patients in JapaN (SEASON) is a prospective observational multicenter study and here we report the baseline clinical characteristics, including atherosclerosis risk factor prevalence, in PAD patients treated with antiplatelet agents. METHODS AND RESULTS: The SEASON registry enrolled 11,375 patients in 1,745 institutions and the data for 10,322 patients were analyzed. At baseline, the average age was 73.8±9.9 years, 60.0% were male and 83.9% were in Fontaine stage I or II. They had arteriosclerosis risk factors, such as current smoking (16.2%), hypertension (61.5%), diabetes mellitus (38.3%) and dyslipidemia (38.8%). There were complications including heart disease (29.7%), cerebrovascular disease (17.1%) and chronic kidney disease (14.3%). A subpopulation analysis revealed that the proportions of patients with risk factors were high in patients with lower ankle-brachial pressure index value. CONCLUSIONS: The baseline characteristics of the SEASON population demonstrate that real-world PAD patients have cardiovascular risk factors and comorbidities next to definite PAD patients. Further analysis of this database will contribute to understanding the real-world situation of PAD patients receiving antiplatelet therapy in Japan. (Circ J 2016; 80: 712-721).


Assuntos
Arteriosclerose Obliterante , Doença Arterial Periférica , Inibidores da Agregação Plaquetária/administração & dosagem , Sistema de Registros , Adulto , Idoso , Idoso de 80 Anos ou mais , Arteriosclerose Obliterante/sangue , Arteriosclerose Obliterante/tratamento farmacológico , Arteriosclerose Obliterante/epidemiologia , Feminino , Humanos , Incidência , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Doença Arterial Periférica/sangue , Doença Arterial Periférica/tratamento farmacológico , Doença Arterial Periférica/epidemiologia , Fatores de Risco
20.
Int Heart J ; 56(6): 632-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26549399

RESUMO

Buerger disease is a rare disease of unknown etiology and cannot be treated by bypass surgery or percutaneous re-endovascularization. Although the need for effective limb ischemia prevention strategies is increasingly being recognized, effective preventative strategies are insufficient. The aim of this study using a new pulsed ultrasound device, SX-1001, is to determine whether treatment using SX-1001 can mitigate rest pain and improve blood supply to ischemic legs in patients with Buerger disease. This study is a multicenter, double-blinded, parallel randomized clinical trial testing the efficacy and safety of SX-1001. Treatment using SX-1001 is expected to result in reduction of the visual analog scale score for pain in Buerger disease patients who have Fontaine stage III. A total of 44 patients from 20 hospitals in Japan will be enrolled. The primary endpoint of the trial is a change in rest pain intensity on the visual analog scale score from baseline to 24 weeks. This trial will be the first to show the safety and efficacy of low-intensity pulsed ultrasound using SX-1001 for clinical symptoms in patients with Buerger disease. Low-intensity pulsed ultrasound may be a new therapy for limb ischemia. Ethical approval has been obtained from each of the participating institutes. Study findings will be disseminated through peer-reviewed journals and at scientific conferences.This study is registered at UMIN Clinical Trial Registry (UMIN000014757).


Assuntos
Extremidades/irrigação sanguínea , Isquemia , Tromboangiite Obliterante , Terapia por Ultrassom , Ondas Ultrassônicas , Caminhada , Adulto , Método Duplo-Cego , Feminino , Humanos , Isquemia/etiologia , Isquemia/terapia , Masculino , Pessoa de Meia-Idade , Manejo da Dor/métodos , Medição da Dor , Tromboangiite Obliterante/complicações , Tromboangiite Obliterante/diagnóstico , Tromboangiite Obliterante/fisiopatologia , Tromboangiite Obliterante/terapia , Resultado do Tratamento , Terapia por Ultrassom/efeitos adversos , Terapia por Ultrassom/métodos
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