366 research outputs found

    Advanced glycation end products modulate transcriptional regulation in mesangial cells

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    Advanced glycation end products modulate transcriptional regulation in mesangial cells. Advanced glycation end products (AGEs) stimulate synthesis of extracellular matrix (ECM) in a receptor-mediated manner on mesangial cells. In the present study, we examined the transcriptional regulation of the gene for type IV collagen [(IV)collagen], which is one of the major components of mesangial sclerosis, after stimulation of AGEs on mesangial cells. The methylation pattern of the promoter/enhancer region of (IV)collagen gene was similar in AGE-treated and control cells. AGEs significantly increased the transcriptional activity of the (IV)collagen gene, as measured by transient transaction assays using the reporter gene construct containing (IV)collagen promoter/enhancer and the chloramphenicol acetyltransferase gene. AGEs also increased smooth muscle α-actin mRNA levels as well as its transcriptional activity. Nuclear factor binding of the promoter of (IV)collagen gene was stimulated by AGEs. Furthermore, AGEs dramatically decreased the mRNA levels of (IV)collagen promoter binding protein (MSW), a larger subunit of DNA replication complex, AP1. These results suggest that AGEs increase expression of (IV)collagen gene by modulating the levels of promoter binding proteins. These transcriptional events may play a critical role in ECM accumulation in response to AGEs

    Soluble lectin-like oxidized LDL receptor-1 (sLOX-1) as a sensitive and specific biomarker for acute coronary syndrome—Comparison with other biomarkers

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    SummaryBackgroundLectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) appears to be involved in atherosclerotic plaque vulnerability and rupture. Circulating soluble LOX-1 (sLOX-1) levels are dramatically elevated in patients with acute coronary syndrome (ACS), and its diagnostic sensitivity and specificity is superior to high-sensitivity C-reactive protein (hs-CRP). In this study, we have compared the diagnostic value of sLOX-1 for ACS with those of troponin T (TnT) and heart-type fatty acid binding protein (H-FABP).MethodsOne hundred and seven patients who underwent coronary angiography (CAG), including 18 ACS and 89 non-ACS patients were enrolled. Peripheral blood samples were obtained during the emergent or elective CAG. The non-ACS group consisted of 30 patients with normal CAG, 30 stable angina pectoris patients controlled by medical treatment, and 29 patients with stable angina who required elective coronary revascularization (percutaneous coronary intervention or coronary artery bypass graft).ResultsAge, gender, lipid profiles, or prevalence of diabetes, smoking, or hypertension were not significantly different between ACS and non-ACS. These factors did not significantly affect blood sLOX-1 levels. Circulating sLOX-1, TnT, and H-FABP levels were significantly higher in ACS than non-ACS. Area under the curve (AUC) values of the receiver-operating characteristic curves were 0.948, 0.704, and 0.691 for sLOX-1, TnT, and H-FABP, respectively. In a TnT-negative (<0.03ng/mL) subgroup, the AUC values for sLOX-1 and H-FABP were 0.848 and 0.476, respectively.ConclusionCirculating sLOX-1 is a more sensitive and specific biomarker for ACS than TnT and H-FABP, and provides additional diagnostic values when measured in combination with TnT

    Junctional adhesion molecule (JAM) binds to PAR-3: a possible mechanism for the recruitment of PAR-3 to tight junctions

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    At tight junctions (TJs), claudins with four transmembrane domains are incorporated into TJ strands. Junctional adhesion molecule (JAM), which belongs to the immunoglobulin superfamily, is also localized at TJs, but it remains unclear how JAM is integrated into TJs. Immunoreplica electron microscopy revealed that JAM showed an intimate spatial relationship with TJ strands in epithelial cells. In L fibroblasts expressing exogenous JAM, JAM was concentrated at cell–cell adhesion sites, where there were no strand-like structures, but rather characteristic membrane domains free of intramembranous particles were detected. These domains were specifically labeled with anti-JAM polyclonal antibody, suggesting that JAM forms planar aggregates through their lateral self-association. Immunofluorescence microscopy and in vitro binding assays revealed that ZO-1 directly binds to the COOH termini of claudins and JAM at its PDZ1 and PDZ3 domains, respectively. Furthermore, another PDZ-containing polarity-related protein, PAR-3, was directly bound to the COOH terminus of JAM, but not to that of claudins. These findings led to a molecular architectural model for TJs: small aggregates of JAM are tethered to claudin-based strands through ZO-1, and these JAM aggregates recruit PAR-3 to TJs. We also discuss the importance of this model from the perspective of the general molecular mechanisms behind the recruitment of PAR proteins to plasma membranes

    Fibulin-5/DANCE has an elastogenic organizer activity that is abrogated by proteolytic cleavage in vivo

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    Elastic fibers are required for the elasticity and integrity of various organs. We and others previously showed that fibulin-5 (also called developing arteries and neural crest EGF-like [DANCE] or embryonic vascular EGF-like repeat–containing protein [EVEC]) is indispensable for elastogenesis by studying fibulin-5–deficient mice, which recapitulate human aging phenotypes caused by disorganized elastic fibers (Nakamura, T., P.R. Lozano, Y. Ikeda, Y. Iwanaga, A. Hinek, S. Minamisawa, C.F. Cheng, K. Kobuke, N. Dalton, Y. Takada, et al. 2002. Nature. 415:171–175; Yanagisawa, H., E.C. Davis, B.C. Starcher, T. Ouchi, M. Yanagisawa, J.A. Richardson, and E.N. Olson. 2002. Nature. 415:168–171). However, the molecular mechanism by which fiblin-5 contributes to elastogenesis remains unknown. We report that fibulin-5 protein potently induces elastic fiber assembly and maturation by organizing tropoelastin and cross-linking enzymes onto microfibrils. Deposition of fibulin-5 on microfibrils promotes coacervation and alignment of tropoelastins on microfibrils, and also facilitates cross-linking of tropoelastin by tethering lysyl oxidase-like 1, 2, and 4 enzymes. Notably, recombinant fibulin-5 protein induced elastogenesis even in serum-free conditions, although elastogenesis in cell culture has been believed to be serum-dependent. Moreover, the amount of full-length fibulin-5 diminishes with age, while truncated fibulin-5, which cannot promote elastogenesis, increases. These data suggest that fibulin-5 could be a novel therapeutic target for elastic fiber regeneration

    MicroRNA-133 regulates the expression of GLUT4 by targeting KLF15 and is involved in metabolic control in cardiac myocytes

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    GLUT4 shows decreased levels in failing human adult hearts. We speculated that GLUT4 expression in cardiac muscle may be fine-tuned by microRNAs. Forced expression of miR-133 decreased GLUT4 expression and reduced insulin-mediated glucose uptake in cardiomyocytes. A computational miRNA target prediction algorithm showed that KLF15 is one of the targets of miR-133. It was confirmed that over-expression of miR-133 reduced the protein level of KLF15, which reduced the level of the downstream target GLUT4. Cardiac myocytes infected with lenti-decoy, in which the 3′UTR with tandem sequences complementary to miR-133 was linked to the luciferase reporter gene, had decreased miR-133 levels and increased levels of GLUT4. The expression levels of KLF15 and GLUT4 were decreased at the left ventricular hypertrophy and congestive heart failure stage in a rat model. The present results indicated that miR-133 regulates the expression of GLUT4 by targeting KLF15 and is involved in metabolic control in cardiomyocytes

    A Case of Advanced Hepatocellular Carcinoma with Portal Vein Tumor Thrombus Refractory to Epirubicin That Showed Marked Decrease in Tumor Markers after Transcatheter Arterial Infusion with Miriplatin

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    Miriplatin, a cisplatin derivative with a high affinity for iodized ethyl esters of fatty acids from poppy seed oil, is a novel chemotherapeutic agent designed for use in the transarterial treatment of hepatocellular carcinoma (HCC). Here, we describe transcatheter arterial infusion (TAI) using miriplatin to treat a case of advanced HCC with portal vein tumor thrombus (PVTT) refractory to TAI with epirubicin. A 66-year-old man with advanced hepatitis C virus-related HCC with PVTT in the right lobe of the liver was treated with TAI with epirubicin suspended in iodized oil; however, tumor marker levels (alpha-fetoprotein and des-gamma-carboxy protein) did not decrease. Next, he was treated twice with TAI with miriplatin suspended in iodized oil. The tumor marker levels markedly decreased to a nearly normal range and the size of the main tumor was markedly reduced according to dynamic computed tomography. No serious adverse events occurred during the course of treatment with TAI and miriplatin. Therefore, we suggest that TAI with miriplatin is a safe and effective treatment option for advanced HCCs refractory to TAI with epirubicin

    Antitumor effect of WEE1 blockade as monotherapy or in combination with cisplatin in urothelial cancer

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    Overcoming cisplatin (CDDP) resistance is a major issue in urothelial cancer (UC), in which CDDP-based chemotherapy is the first-line treatment. WEE1, a G2/M checkpoint kinase, confers chemoresistance in response to genotoxic agents. However, the efficacy of WEE1 blockade in UC has not been reported. MK-1775, a WEE1 inhibitor also known as AZD-1775, blocked proliferation of UC cell lines in a dose-dependent manner irrespective of TP53 status. MK-1775 synergized with CDDP to block proliferation, inducing apoptosis and mitotic catastrophe in TP53-mutant UC cells but not in TP53-WT cells. Knocking down TP53 in TP53-WT cells induced synergism of MK-1775 and CDDP. In UMUC3 cell xenografts and two patient-derived xenograft lines with MDM2 overexpression, in which the p53/cell cycle pathway was inactivated, AZD-1775 combined with CDDP suppressed tumor growth inducing both M-phase entry and apoptosis, whereas AZD-1775 alone was as effective as the combination in RT4 cell xenografts. Drug susceptibility assay using an ex vivo cancer tissue-originated spheroid system showed correlations with the in vivo efficacy of AZD-1775 alone or combined with CDDP. We determined the feasibility of the drug susceptibility assay using spheroids established from UC surgical specimens obtained by transurethral resection. In conclusion, WEE1 is a promising therapeutic target in the treatment of UC, and a highly specific small molecule inhibitor is currently in early phase clinical trials for cancer. Differential antitumor efficacy of WEE1 blockade alone or combined with CDDP could exist according to p53/cell cycle pathway activity, which might be predictable using an ex vivo 3D primary culture system

    Prevalence of the metabolic syndrome in elderly and middle-aged Japanese

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    AbstractBackground/PurposeDiagnosis and management of the metabolic syndrome (MetS) are beneficial for successful aging. In spite of several criteria for MetS, there is little information on cardiometabolic risk clustering in elderly Japanese. The purpose of this study was, therefore, to determine the relationship between age-associated changes in obesity and metabolic components in the Japanese.MethodsWe analyzed data from the nationwide survey conducted in 2000. Using Adult Treatment Panel III (ATP III) and Japanese diagnostic criteria for MetS, we analyzed 2366 people aged from 40 to 79 years (men, 1425 and women, 941) from the total participants.ResultsThe prevalence of MetS was almost three fold higher by modified ATP III, International Diabetes Federation, and Japanese criteria, in elderly women than in middle-aged women, whereas no difference was found between middle-aged and elderly men by the three criteria. A marked increase in the prevalence of MetS was found by modified ATP III and International Diabetes Federation criteria compared with that by the Japanese criteria in women. Among the risk factors, the prevalence of central obesity and dyslipidemia increased only in women and that of high fasting glucose and high blood pressure increased in both genders with aging. Among the MetS subjects who fulfilled the modified ATP III criteria, more clustering of risk was observed in elderly than in middle-aged subjects, especially in women. Blood pressure increased and triglyceride decreased in both genders, and non-high-density-lipoprotein cholesterol decreased in elderly men. The prevalence of dyslipidemia decreased in elderly men.ConclusionAging is an important factor that affects the metabolic abnormality, and aging of the population would lead to increase in the prevalence of MetS. Therefore, the development of better approaches to the prevention and management of MetS is necessary for successful aging in our society

    The effect of pegylated interferon-alpha2b and ribavirin combination therapy for chronic hepatitis C infection in elderly patients

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    <p>Abstract</p> <p>Background</p> <p>The clearance of hepatitis C virus infection by interferon therapy significantly reduces the incidence of hepatocellular carcinoma and death in elderly chronic hepatitis patients. However, there are few reports concerning the efficacy and safety of pegylated interferon-alpha2b plus ribavirin combination therapy in elderly patients. The aims of the present study were to examine the effect and safety of pegylated interferon-alpha2b plus ribavirin combination therapy in 427 patients with chronic hepatitis C infection. We compared the rates of sustained virological response--defined as the absence of detectable hepatitis C virus in serum 24 weeks after the treatment ended--and the treatment discontinuation rate between 319 younger patients aged < 65 years and 108 elderly patients aged ≥ 65 years. We also examined the factors contributing to a sustained virological response.</p> <p>Results</p> <p>There was no significant difference in the sustained virological response rate between younger patients and elderly patients according to their hepatitis C virus genotype (41.5% (100/241) and 40.7% (35/86) for genotype 1; <it>P </it>= 0.899, 89.7% (70/78) and 86.4% (19/22) for genotype 2; <it>P </it>= 0.703, respectively). There was also no significant difference in the treatment discontinuation rate between the two age groups (10.3% (33/319) and 13.9% (15/108), respectively; <it>P </it>= 0.378). There were no serious adverse events requiring hospitalization. The factors contributing significantly to a sustained virological response in elderly patients were gender, hepatitis C virus genotype, platelet count, and the presence of a rapid or early virological response (undetectable hepatitis C virus in serum at weeks 4 or 12 of treatment, respectively). However, upon multivariate analysis, the presence of an early virological response was the only significant factor (odds ratio: 0.115, 95% confidence interval: 0.040- 0.330, <it>P </it>< 0.001).</p> <p>Conclusions</p> <p>The efficacy and safety of pegylated interferon-alpha2b plus ribavirin combination therapy in elderly patients are not always inferior to those in younger patients. Obtaining an early virological response may be essential to achieve a sustained virological response in elderly patients with chronic hepatitis C infection.</p
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