Metal ions are used in various situations in living organisms and as a part of functional materials. Since the excessive intake of metal ions can cause health hazards and environmental pollution, the ...development of new molecules that can monitor metal ion concentrations with high sensitivity and selectivity is strongly desired. DNA can form various structures, and these structures and their properties have been used in a wide range of fields, including materials, sensors, and drugs. Guanine-rich sequences respond to metal ions and form G-quadruplex structures and G-wires, which are the self-assembling macromolecules of G-quadruplex structures. Therefore, guanine-rich DNA can be applied to a metal ion-detection sensor and functional materials. In this study, the IRDAptamer library originally designed based on G-quadruplex structures was used to screen for Mn2+, which is known to induce neurodegenerative diseases. Circular dichroism and fluorescence analysis using Thioflavin T showed that the identified IRDAptamer sequence designated MnG4C1 forms a non-canonical G-quadruplex structure in response to low concentrations of Mn2+. A serum resistance and thermostability analysis revealed that MnG4C1 acquired stability in a Mn2+-dependent manner. A Förster resonance energy transfer (FRET) system using fluorescent molecules attached to the termini of MnG4C1 showed that FRET was effectively induced based on Mn2+-dependent conformational changes, and the limit of detection (LOD) was 0.76 µM for Mn2+. These results suggested that MnG4C1 can be used as a novel DNA-based Mn2+-detecting molecule.
Metal ions are used in various situations in living organisms and as a part of functional materials. Since the excessive intake of metal ions can cause health hazards and environmental pollution, the ...development of new molecules that can monitor metal ion concentrations with high sensitivity and selectivity is strongly desired. DNA can form various structures, and these structures and their properties have been used in a wide range of fields, including materials, sensors, and drugs. Guanine-rich sequences respond to metal ions and form G-quadruplex structures and G-wires, which are the self-assembling macromolecules of G-quadruplex structures. Therefore, guanine-rich DNA can be applied to a metal ion-detection sensor and functional materials. In this study, the IRDAptamer library originally designed based on G-quadruplex structures was used to screen for Mnsup.2+, which is known to induce neurodegenerative diseases. Circular dichroism and fluorescence analysis using Thioflavin T showed that the identified IRDAptamer sequence designated MnG4C1 forms a non-canonical G-quadruplex structure in response to low concentrations of Mnsup.2+. A serum resistance and thermostability analysis revealed that MnG4C1 acquired stability in a Mnsup.2+-dependent manner. A Förster resonance energy transfer (FRET) system using fluorescent molecules attached to the termini of MnG4C1 showed that FRET was effectively induced based on Mnsup.2+-dependent conformational changes, and the limit of detection (LOD) was 0.76 µM for Mnsup.2+. These results suggested that MnG4C1 can be used as a novel DNA-based Mnsup.2+-detecting molecule.
Metal ions are used in various situations in living organisms and as a part of functional materials. Since the excessive intake of metal ions can cause health hazards and environmental pollution, the ...development of new molecules that can monitor metal ion concentrations with high sensitivity and selectivity is strongly desired. DNA can form various structures, and these structures and their properties have been used in a wide range of fields, including materials, sensors, and drugs. Guanine-rich sequences respond to metal ions and form G-quadruplex structures and G-wires, which are the self-assembling macromolecules of G-quadruplex structures. Therefore, guanine-rich DNA can be applied to a metal ion-detection sensor and functional materials. In this study, the IRDAptamer library originally designed based on G-quadruplex structures was used to screen for Mn
, which is known to induce neurodegenerative diseases. Circular dichroism and fluorescence analysis using Thioflavin T showed that the identified IRDAptamer sequence designated MnG4C1 forms a non-canonical G-quadruplex structure in response to low concentrations of Mn
. A serum resistance and thermostability analysis revealed that MnG4C1 acquired stability in a Mn
-dependent manner. A Förster resonance energy transfer (FRET) system using fluorescent molecules attached to the termini of MnG4C1 showed that FRET was effectively induced based on Mn
-dependent conformational changes, and the limit of detection (LOD) was 0.76 µM for Mn
. These results suggested that MnG4C1 can be used as a novel DNA-based Mn
-detecting molecule.
Neutral transport related to recycling phenomena on two limiters installed in the central-cell was studied in the GAMMA 10 tandem mirror plasmas. Dependence of iris limiter is investigated in terms ...of plasma diamagnetism and Hα-line intensity. It was found that a plasma diamagnetic signal was improved and Hα-line intensity near the iris limiter increased if the diameter of the iris limiter shrank to 340 mm. Fully 3-dimensional Monte-Carlo simulation (DEGAS) was executed with the recycling source on the limiters. The neutral sources on the limiters were consistently given so as to satisfy 2-dimensional (2-d) image obtained by a high-speed camera. The determined Hα-line intensity from DEGAS well explained the experimental result. The simulation result, in the 340 mm case, predicted the reduction in the peak value of Hα-line intensity on the central limiter and the enhancement on the iris limiter. It suggests that the reduction of the recycling on the central limiter makes it possible to lead the better plasma performance.
In the central-cell of the GAMMA 10 tandem mirror, a medium-speed camera (CCD camera, 400 frames per second, 216× 640 pixel) has been installed for the observation of plasma behavior. This camera ...system is designed for monitoring the plasma position and movement in the whole discharge duration. The captured two-dimensional (2-D) images are automatically displayed just after the plasma shot and stored sequentially shot by shot. This system has been established as a helpful tool for optimizing the plasma production and heating systems by measuring the plasma behavior in several experimental conditions. The camera system shows that the intensity of the visible light emission on the central-cell limiter accompanied by central electron cyclotron heating (C-ECH) correlate with the wall conditioning and immersion length of a movable limiter (iris limiter) in the central cell.
Isotopic analysis, together with size distribution analyses of platinum nanoparticles (Pt NPs) have been made by a multiple collector-ICP-mass spectrometer equipped with a high-time resolution data ...acquisition system (HTR-MC-ICP-MS). With the present system, time-integration efficiency of nearly 100% was achieved from up to four isotopic signals, enabling us to measure both the size and isotopic ratios from a single NP. Based on the 195Pt/194Pt ratios obtained from more than 1000 particles, the precisions of the 195Pt/194Pt ratio measurements on 30 nm, 50 nm, and 70 nm were approximately 40% (2SD), 20% (2SD), and 10% (2SD). These results were comparable to possible variations in the 195Pt/194Pt ratios estimated by counting statistics of the isotopic signals, suggesting that the isotopic ratio measurements could be achieved from transient signal events originating from NPs. The data obtained here demonstrated that the HTR-MC-ICP-MS technique can become a powerful tool to monitor the elemental/isotopic ratios from single NPs.
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•Development of multiple collector inductively coupled plasma mass spectrometer equipped with a high-time resolution data acquisition system•Simultaneous detection of isotopic signals even from transient signal induced by the nanoparticles•Repeatability of isotopic ratio of nanoparticles is controlled by the counting statistics of the signal intensity•Size distribution of samples agreed well with the data shown in product information measured by transmission electron microscope
MicroRNAs (miRNAs) play crucial roles in the development of various diseases, including chronic kidney disease (CKD). Although previous studies in clinically severe patients have investigated ...associations between CKD and miRNAs, with particular attention on renal fibrosis, relationships in a general population have yet to be established. The aim of this study was to examine the relationship between expression level of circulating miRNAs and CKD in a middle-aged Japanese population.
A final total of 513 individuals (216 men and 297 women) who participated in the health check-up program in 2012 were included in our analysis. Quantitative real-time polymerase chain reaction was used to determine expression levels of 22 miRNAs. Estimated glomerular filtration rate (eGFR) was calculated based on serum creatinine level, sex, and age. Participants with eGFR <60 mL/min/1.73 m
were defined as having CKD.
Three different miRNAs (miR-17, miR-21, and miR-150) showed significant correlations with eGFR after Bonferroni correction and were selected for further analyses. Expression levels of miR-17, miR-21, and miR-150 miRNAs were positively associated with eGFR after adjusting for potential confounders (P = 0.004, 0.002, and 0.004, respectively). Logistic regression analyses showed significantly lower odds ratios for CKD (eGFR <60 mL/min/1.73 m
) in the highest tertile of all three miRNAs (miR-17, miR-21, and miR-150) compared with the lowest tertile (P = 0.003, 0.01, and 0.02, respectively).
We found that three circulating miRNAs were significantly associated with CKD in a general Japanese population, which suggested that these miRNAs may be biomarkers for CKD among general adults.
Aim: Aberrant global DNA methylation is involved in the development of several diseases, including cardiovascular disease (CVD). We investigated whether the methylation of long interspersed nuclear ...element-1 (LINE-1) in leukocytes is associated with dyslipidemia, a major risk factor for CVD, in the Japanese general population.Methods: We conducted a cross-sectional study consisting of 420 Japanese subjects (187 men and 233 women) without a clinical history of cancer, stroke, or ischemic heart disease. LINE-1 DNA methylation levels in leukocytes were measured using a pyrosequencing method.Results: Significantly higher odds ratios (ORs) for hypermethylation were observed in the high LDL cholesterol and high LDL/HDL ratio groups than the corresponding normal group (high LDLC group: OR, 1.88; 95% confidence interval CI, 1.20–2.96, high LDL/HDL ratio group: OR, 1.90; 95% CI, 1.20–3.01). Subjects with 2 or more lipid abnormalities had significantly higher ORs for hypermethylation than those with no lipid abnormality (OR, 2.31; 95% CI, 1.11–4.82).Conclusion: LINE-1 DNA hypermethylation in leukocytes was associated with CVD risk profiles: high LDLC, high LDL/HDL ratio, and the degree of abnormal lipid metabolism.
Metabolic syndrome (MetS) is cluster of metabolic diseases, including abdominal obesity, hyperglycemia, high blood pressure, and dyslipidemia, that directly escalate the risk of type 2 diabetes, ...heart disease, and stroke. Thioredoxin-interacting protein (TXNIP) is a binding protein for thioredoxin, a molecule that is a key inhibitor of cellular oxidation, and thus regulates the cellular redox state. Epigenetic alteration of the TXNIP-encoding locus has been associated with components of MetS. In the present study, we sought to determine whether the level of TXNIP methylation in blood is associated with MetS in the general Japanese population. DNA was extracted from the peripheral blood cells of 37 subjects with and 392 subjects without MetS. The level of TXNIP methylation at cg19693031 was assessed by the bisulfite-pyrosequencing method. We observed that TXNIP methylation levels were lower in MetS subjects (median 74.9%, range 71.7–78.4%) than in non-MetS subjects (median 77.7%, range 74.4–80.5%; p = 0.0024). Calculation of the confounding factor-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for hypomethylation revealed that subjects with MetS exhibited significantly higher ORs for hypomethylation than did those without MetS (OR, 2.92; 95% CI, 1.33–6.62; p = 0.009). Our findings indicated that lower levels of TXNIP methylation are associated with MetS in the general Japanese population. Altered levels of DNA methylation in TXNIP at cg19693031 might play an important role in the pathogenesis of MetS.
Thioredoxin-interacting protein (TXNIP) plays an important role in glucose metabolism, and its expression is regulated by DNA methylation (DNAm). Although the association between TXNIP DNAm and type ...2 diabetes mellitus has been demonstrated in studies with a cross-sectional design, prospective studies are needed. We therefore examined the association between TXNIP DNAm levels and longitudinal changes in glycemic traits by conducting a longitudinal study involving 169 subjects who underwent two health checkups in 2015 and 2019. We used a pyrosequencing assay to determine TXNIP DNAm levels in leukocytes (cg19693031). Logistic regression analyses were performed to assess the associations between dichotomized TXNIP DNAm levels and marked increases in glycemic traits. At four years, the TXNIP DNA hypomethylation group had a higher percentage of changes in fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) compared to those in the hypermethylation group. The adjusted odds ratios for FPG and HbA1c levels were significantly higher in the TXNIP DNA hypomethylation group than in the hypermethylation group. We found that TXNIP DNA hypomethylation at baseline was associated with a marked increase in glycemic traits. Leukocyte TXNIP DNAm status could potentially be used as an early biomarker for impaired glucose homeostasis.
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