43 research outputs found

    ANKRD1, the gene encoding cardiac ankyrin repeat protein, is a novel dilated cardiomyopathy gene.

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    OBJECTIVES: We evaluated ankyrin repeat domain 1 (ANKRD1), the gene encoding cardiac ankyrin repeat protein (CARP), as a novel candidate gene for dilated cardiomyopathy (DCM) through mutation analysis of a cohort of familial or idiopathic DCM patients, based on the hypothesis that inherited dysfunction of mechanical stretch-based signaling is present in a subset of DCM patients. BACKGROUND: CARP, a transcription coinhibitor, is a member of the titin-N2A mechanosensory complex and translocates to the nucleus in response to stretch. It is up-regulated in cardiac failure and hypertrophy and represses expression of sarcomeric proteins. Its overexpression results in contractile dysfunction. METHODS: In all, 208 DCM patients were screened for mutations/variants in the coding region of ANKRD1 using polymerase chain reaction, denaturing high-performance liquid chromatography, and direct deoxyribonucleic acid sequencing. In vitro functional analyses of the mutation were performed using yeast 2-hybrid assays and investigating the effect on stretch-mediated gene expression in myoblastoid cell lines using quantitative real-time reverse transcription-polymerase chain reaction. RESULTS: Three missense heterozygous ANKRD1 mutations (P105S, V107L, and M184I) were identified in 4 DCM patients. The M184I mutation results in loss of CARP binding with Talin 1 and FHL2, and the P105S mutation in loss of Talin 1 binding. Intracellular localization of mutant CARP proteins is not altered. The mutations result in differential stretch-induced gene expression compared with wild-type CARP. CONCLUSIONS: ANKRD1 is a novel DCM gene, with mutations present in 1.9% of DCM patients. The ANKRD1 mutations may cause DCM as a result of disruption of the normal cardiac stretch-based signaling

    Tcap gene mutations in hypertrophic cardiomyopathy and dilated cardiomyopathy

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    ObjectivesWe sought to explore the relationship between a Tcap gene (TCAP)abnormality and cardiomyopathy.BackgroundHypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) cause severe heart failure and sudden death. Recent genetic investigations have revealed that mutations of genes encoding Z-disc components, including titin and muscle LIM protein (MLP), are the primary cause of both HCM and DCM. The Z-disc plays a role in establishing the mechanical coupling of sarcomeric contraction and stretching, with the titin/Tcap/MLP complex serving as a mechanical stretch sensor. Tcap interacts with the calsarcin, which tethers the calcineurin to the Z-disc.MethodsThe TCAPwas analyzed in 346 patients with HCM (236 familial and 110 sporadic cases) and 136 patients with DCM (34 familial and 102 sporadic cases). Two different in vitro qualitative assays—yeast two-hybrid and glutathion S-transferase pull-down competition—were performed in order to investigate functional changes in Tcap's interaction with MLP, titin, and calsarcin-1 caused by the identified mutations and a reported DCM-associated mutation, R87Q.ResultsTwo TCAPmutations, T137I and R153H, were found in patients with HCM, and another TCAPmutation, E132Q, was identified in a patient with DCM. It was demonstrated by the qualitative assays that the HCM-associated mutations augment the ability of Tcap to interact with titin and calsarcin-1, whereas the DCM-associated mutations impair the interaction of Tcap with MLP, titin, and calsarcin-1.ConclusionsThese observations suggest that the difference in clinical phenotype (HCM or DCM) may be correlated with the property of altered binding among the Z-disc components

    Peptide Substrates for Rho-Associated Kinase 2 (Rho-Kinase 2/ROCK2)

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    Peptide substrates sensitive for a certain protein kinase could be important for new-drug development and to understand the mechanism of diseases. Rho-associated kinase (Rho-kinase/ROCK) is a serine/threonine kinase, and plays an important part in cardiovascular disease, migration and invasion of tumor cells, and in neurological disorders. The purpose of this study was to find substrates with high affinity and sensitivity for ROCK2. We synthesized 136 peptide substrates from protein substrates for ROCK2 with different lengths and charged peptides. Incorporation of 32P [counts per minute (CPM)] for each peptide substrate was determined by the radiolabel assay using [γ-32P]ATP. When the top five peptide substrates showing high CPMs (R4, R22, R133, R134, and R135) were phosphorylated by other enzymes (PKA, PKCα, and ERK1), R22, R133, and R135 displayed the highest CPM level for ROCK2 compared with other enzymes, whereas R4 and R134 showed similar CPM levels for ROCK2 and PKCα. We hypothesize that R22, R133, and R135 can be useful peptide substrates for ROCK2

    DOCK2 is involved in the host genetics and biology of severe COVID-19

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    「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

    Molecular Etiology and Pathogenesis of Hereditary Cardiomyopathy

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    Contribution of Genetic Factors to the Pathogenesis of Dilated Cardiomyopathy

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    Green Policymaking in Japanese Municipalities: An Empirical Study on External and Internal Contextual Factors

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    This article examines the establishment and publication of green plans and green public procurement (GPP) policies in Japanese municipalities. The purpose of the study was to investigate these green policymaking initiatives from a contingency theory perspective. The first research question examined contextual factors for green policymaking. The second research question focused on barriers and enablers. For RQ1, through hypothesis testing and a regression analysis (n = 1663), we found that green policymaking differs by organization location, organization size, and organizational green capabilities. More specifically, we identified prefectures where municipalities score relatively higher as well as lower. Second, we found that larger (vs. smaller) municipalities undertake more (vs. less) green policymaking initiatives. Third, we observed that organizations with more (vs. less) green capabilities develop more (vs. less) green initiatives. For RQ2, through a descriptive and cluster analysis, we identified dominant barriers and enablers to establishing a GPP policy. The dominant barriers include a lack of information, lack of staff, and cost concerns, whereas manuals and example forms are important enablers. These findings are highly relevant to understanding and supporting green policymaking in Japanese municipalities

    Advancement of Green Public Purchasing by Category: Do Municipality Green Purchasing Policies Have Any Role in Japan?

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    The aim of this paper is to identify (1) the categories in which it is easier or more difficult for local municipalities to implement green purchasing and (2) the role and extent of green purchasing policy (GPP) in promoting green purchasing. To characterize the green purchasing potential of different categories, we examine the green purchasing rate, or the ratio of green products/services to total products/services purchased, of 21 categories of items. We employ data from a unique survey conducted by the Japanese Ministry of the Environment, which provides data on green procurement in municipalities. We observe that air conditioners suffer from low green purchasing rates, whereas most municipalities purchase green products in the paper products and stationery categories. We also examine the relationship between green purchasing rates and GPPs to identify the role and extent of GPPs. Our regression analyses reveal that the presence of a GPP is associated with higher implementation and measurement rates of green purchasing. This pattern is particularly evident for the categories in which many municipalities without GPPs purchase green products but, in most cases, do not measure their green purchasing rate
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