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Purpose: Neuropilin-2 (NRP2) is a multifunctional single-pass transmembrane receptor that binds to two disparate ligands, namely, vascular endothelial growth factors (VEGFs) and semaphorins (SEMAs). It is reportedly involved in neuronal and vascular development. In this study, we uncovered the exact functional role of NRP2 and its molecular mechanism during aggressive behaviors and lymph node (LN) metastasis in human head and neck cancer (HNC) and identified algal methanol extract as a potential novel NRP2 inhibitor. Methods: In silico analyses and immunohistochemistry were used to investigate the relationship between NRP2 expression and the prognosis of HNC patients. The functional role of NRP2 on the proliferation, migration, invasion, and cancer stem cell (CSC) properties of HNC cells was examined by MTS, soft agar, clonogenic, transwell migration and invasion assays, and sphere formation assays. Signaling explorer antibody array, western blot, and qPCR were performed toward the investigation of a molecular mechanism that is related to NRP2. Results: NRP2 was highly expressed in HNC and positively correlated with LN metastasis and advanced tumor stage and size in patients. Using loss- or gain-of-function approaches, we found that NRP2 promoted the proliferative, migratory, and invasive capacities of human HNC cells. Furthermore, NRP2 regulated Sox2 expression to exhibit aggressiveness and CSC properties of human HNC cells. We demonstrated that p90 ribosomal S6 kinase 1 (RSK1) elevates the aggressiveness and CSC properties of human HNC cells, possibly by mediating NRP2 and Sox2. Zeb1 was necessary for executing the NRP2/RSK1/Sox2 signaling pathway during the induction of epithelial-to-mesenchymal transition (EMT) and aggressive behaviors of human HNC cells. Moreover, the methanol extract of Codium fragile (MECF) repressed NRP2 expression, inhibiting the RSK1/Sox2/Zeb1 axis, which contributed to the reduction of aggressive behaviors of human HNC cells. Conclusions: These findings suggest that NRP2 is a critical determinant in provoking EMT and aggressive behaviors in human HNC through the RSK1/Sox2/Zeb1 axis, and MECF may have the potential to be a novel NRP2 inhibitor for treating metastasis in HNC patients. [ABSTRACT FROM AUTHOR]

Extracellular vesicles (EVs) have been shown as key mediators of extracellular small RNA transport. However, carriers of cell-free messenger RNA (cf-mRNA) in human biofluids and their association with cancer remain poorly understood. Here, we performed a transcriptomic analysis of size-fractionated plasma from lung cancer, liver cancer, multiple myeloma, and healthy donors. Morphology and size distribution analysis showed the successful separation of large and medium particles from other soluble plasma protein fractions. We developed a strategy to purify and sequence ultra-low amounts of cf-mRNA from particle and protein enriched subpopulations with the implementation of RNA spike-ins to control for technical variability and to normalize for intrinsic drastic differences in cf-mRNA amount carried in each plasma fraction. We found that the majority of cf-mRNA was enriched and protected in EVs with remarkable stability in RNase-rich environments. We observed specific enrichment patterns of cancer-associated cf-mRNA in each particle and protein enriched subpopulation. The EV-enriched differentiating genes were associated with specific biological pathways, such as immune systems, liver function, and toxic substance regulation in lung cancer, liver cancer, and multiple myeloma, respectively. Our results suggest that dissecting the complexity of EV subpopulations illuminates their biological significance and offers a promising liquid biopsy approach. Fractionation and characterization of cell-free mRNA carriers - mostly EVs - from various human plasma samples leads to identification of cancer-specific EV enrichment patterns [ABSTRACT FROM AUTHOR]

Sleep stage classification is crucial in diagnosing sleep disorders and monitoring treatment effectiveness, yet it is inconvenient, requiring many electrodes and labor-intensive assessments. Single electroencephalogram (EEG)-based deep learning approaches were proposed to address this issue; however, existing studies have employed deep learning models that are devised for imaging and natural language processing for automated sleep stage classification, which limits their use for capturing sleep patterns or changes over time in EEG signals. This study proposes SleepExpertNet, which is inspired by actual clinical guidelines for scoring sleep stages. The model consists of a representation learning part, which learns the physiological characteristics of EEG sleep signals, and a temporal context modeling part, which learns long- and short-term temporal context information similar to a sleep expert. SleepExpertNet guarantees the highest level of accuracy (accuracy: 90.8%, macro-f1: 86.7) on the expanded Sleep-EDF dataset, surpassing the existing state-of-the-art methods, despite utilizing only single-channel EEG signals. Furthermore, the class imbalance problem, which has been a major obstacle in sleep stage classification research, was also addressed. The proposed model is expected to reduce the workload on clinicians and support diagnostic decision-making, enabling more accurate sleep stage classification. [ABSTRACT FROM AUTHOR]

Purpose: PD-L1 is an immune checkpoint protein that allows cells to evade T-cell-mediated immune responses. Herein, we uncover a tumor-intrinsic mechanism of PD-L1 that is responsible for the progression and aggressiveness of HNC and reveal that the extracts of a brown alga can target the tumor-intrinsic signaling pathway of PD-L1. Methods: The biological functions of PD-L1 in the proliferation and aggressiveness of HNC cells in vitro were examined by metabolic activity, clonogenic, tumorigenicity, wound healing, migration, and invasion assays. The clinical importance of PD-L1 in the prognosis of patients with HNC was analyzed by immunohistochemistry. The relationship between PD-L1 and EMT was confirmed via western blotting, qPCR, and immunocytochemistry. Results: Through our in silico approach, we found that PD-L1 was upregulated in HNC and was correlated with an unfavorable clinical outcome in patients with HNC. PD-L1 was crucial for promoting tumor growth, both in vitro and in vivo. High expression of PD-L1 was closely correlated with LN metastasis in OSCC. PD-L1 facilitated the cytoskeletal reorganization and aggressiveness of HNC cells. Moreover, PD-L1 enhanced the EMT of HNC cells by regulating the Snail/vimentin axis. Consistently, MEIO suppressed the PD-L1/Snail/vimentin axis, thereby inhibiting the aggressiveness of HNC cells. Inhibition of PD-L1 induced by PD-L1 silencing or MEIO treatment caused Snail degradation through a GSK3β-dependent mechanism. The tumor-intrinsic function of PD-L1 could be attributed to the regulation of the GSK3β/Snail/vimentin axis. Conclusion: The discovery of MEIO targeting the tumor-intrinsic function of PD-L1 may prove particularly valuable for the development of novel and effective anticancer drug candidates for HNCs overexpressing PD-L1. [ABSTRACT FROM AUTHOR]

In this study, an Mg–9Al–0.8Zn–0.2Mn–0.3Ca–0.2Y (AZXW9100) alloy having high corrosion and ignition resistance characteristics is recently developed. This study investigates the aging hardening and Mg17Al12 precipitation characteristics of the extruded AZXW9100 alloy by comparing those of a commercial AZ91 counterpart. Both alloys' microstructures consist of equiaxed recrystallized grains and they have an intense basal texture. Unlike the AZ91 alloy with a few Al–Mn particles, the AZXW9100 alloy contains numerous Al2Y, Al8Mn4Y, and Al2Ca particles. As the aging time increases from 0 to 8 h at 200 °C, the hardness increases from 63.6 to 95.4 Hv and 68.8 to 98.3 Hv for the AZ91 and AZXW9100 alloys, respectively. Although the hardness increments during aging and the peak aging times are almost the same for both alloys, their Mg17Al12 precipitation behavior considerably differs. During aging, the number of Mg17Al12 continuous precipitates formed in the AZXW9100 alloy is less than that in the AZ91 alloy because of the lower amount of Al solute atoms in the former. The nucleation and growth of Mg17Al12 discontinuous precipitates (DPs) are also suppressed in the AZXW9100 alloy because of the combined effect by the reduced Al solutes, finer grains, Ca and Y solutes, and second-phase particles. Consequently, the area fraction of DPs of the peak-aged AZXW9100 alloy is nearly half that of the peak-aged AZ91 alloy. This study demonstrates that adding small amounts of Ca and Y to AZ91 alloy causes drastic variations in the Mg17Al12 precipitation behavior during aging. [ABSTRACT FROM AUTHOR]

Cell-free RNA (cfRNA) in plasma reflects phenotypic alterations of both localized sites of cancer and the systemic host response. Here we report that cfRNA sequencing enables the discovery of messenger RNA (mRNA) biomarkers in plasma with the tissue of origin-specific to cancer types and precancerous conditions in both solid and hematologic malignancies. To explore the diagnostic potential of total cfRNA from blood, we sequenced plasma samples of eight hepatocellular carcinoma (HCC) and ten multiple myeloma (MM) patients, 12 patients of their respective precancerous conditions, and 20 non-cancer (NC) donors. We identified distinct gene sets and built classification models using Random Forest and linear discriminant analysis algorithms that could distinguish cancer patients from premalignant conditions and NC individuals with high accuracy. Plasma cfRNA biomarkers of HCC are liver-specific genes and biomarkers of MM are highly expressed in the bone marrow compared to other tissues and are related to cell cycle processes. The cfRNA level of these biomarkers displayed a gradual transition from noncancerous states through precancerous conditions and cancer. Sequencing data were cross-validated by quantitative reverse transcription PCR and cfRNA biomarkers were validated in an independent sample set (20 HCC, 9 MM, and 10 NC) with AUC greater than 0.86. cfRNA results observed in precancerous conditions require further validation. This work demonstrates a proof of principle for using mRNA transcripts in plasma with a small panel of genes to distinguish between cancers, noncancerous states, and precancerous conditions. [ABSTRACT FROM AUTHOR]

The discovery and utility of clinically relevant circulating biomarkers depend on standardized methods that minimize preanalytical errors. Despite growing interest in studying extracellular vesicles (EVs) and cell-free messenger RNA (cf-mRNA) as potential biomarkers, how blood processing and freeze/thaw impacts the profiles of these analytes in plasma was not thoroughly understood. We utilized flow cytometric analysis to examine the effect of differential centrifugation and a freeze/thaw cycle on EV profiles. Utilizing flow cytometry postacquisition analysis software (FCMpass) to calibrate light scattering and fluorescence, we revealed how differential centrifugation and post-freeze/thaw processing removes and retains EV subpopulations. Additionally, cf-mRNA levels measured by RT-qPCR profiles from a panel of housekeeping, platelet, and tissue-specific genes were preferentially affected by differential centrifugation and post-freeze/thaw processing. Critically, freezing plasma containing residual platelets yielded irreversible ex vivo generation of EV subpopulations and cf-mRNA transcripts, which were not removable by additional processing after freeze/thaw. Our findings suggest the importance of minimizing confounding variation attributed to plasma processing and platelet contamination. [ABSTRACT FROM AUTHOR]

Angiotensin II (AngII) has potent cardiac hypertrophic effects mediated through activation of hypertrophic signaling like Wnt/β-Catenin signaling. In the current study, we examined the role of protein arginine methyltransferase 7 (PRMT7) in cardiac function. PRMT7 was greatly decreased in hypertrophic hearts chronically infused with AngII and cardiomyocytes treated with AngII. PRMT7 depletion in rat cardiomyocytes resulted in hypertrophic responses. Consistently, mice lacking PRMT7 exhibited the cardiac hypertrophy and fibrosis. PRMT7 overexpression abrogated the cellular hypertrophy elicited by AngII, while PRMT7 depletion exacerbated the hypertrophic response caused by AngII. Similar with AngII treatment, the cardiac transcriptome analysis of PRMT7-deficient hearts revealed the alteration in gene expression profile related to Wnt signaling pathway. Inhibition of PRMT7 by gene deletion or an inhibitor treatment enhanced the activity of β-catenin. PRMT7 deficiency decreases symmetric dimethylation of β-catenin. Mechanistic studies reveal that methylation of arginine residue 93 in β-catenin decreases the activity of β-catenin. Taken together, our data suggest that PRMT7 is important for normal cardiac function through suppression of β-catenin activity. [ABSTRACT FROM AUTHOR]

Although cardiac tissue is considered a target of gravitational force (g-force), the mechanism of hypergravity on the ion modulation or identification of ion transporters is still unknown. Thus, we determine the effect of hypergravity on a physical force-sensitive cytokine, IL-6 and its related channel activity to investigate rat cardiac function changes in response to accelerated g-force. Serum IL-6 levels and intracellular calcium levels of the right atrium were moderately increased under hypergravity stimulation (4g). IL-6 was involved in the modulation of sodium-potassium-chloride cotransporter (Nkcc) activity. Surprisingly, the right atrium under 4g revealed significantly enhanced Nkcc1 activity. The use of IL-6 on the NKCC1-overexpressed or native NKCC-expressing cells also showed enhanced NKCC1 activity. Hypergravity conditions were also involved in the oxidative stress activated Trpm2 channel and revealed an enhanced expression of the Trpm2 channel under 4g in the rat right atrium. In conclusion, hypergravity revealed that moderate increases in serum IL-6 and enhanced Nkcc1 activity was modulated by IL-6. In addition, enhanced Trpm2 channel expression could be involved in the increased intracellular calcium levels of the right atrium under hypergravitational force. We therefore address that enhanced physical force-sensitive cytokine and oxidative stress by the gravitational force mediate activation of the cotransporter involved in possibilities of edema and calcium loading in cardiac tissue. [ABSTRACT FROM AUTHOR]

The effects of extrusion speed on the microstructure and tensile properties of a recently developed Mg–9Al–0.8Zn–0.9Ca–0.6Y–0.5MM (AZXWMM91100) alloy are investigated by extruding at various ram speeds of 1, 4, 7, 10, and 13 mm/s. Direct extrusion results reveal that numerous small edge cracks form in the sheets extruded at ram speeds between 4 and 10 mm/s, whereas severe hot cracking occurs during extrusion at 13 mm/s. All extruded sheets show a fully recrystallized grain structure containing second-phase particles aligned along the extrusion direction. The average size of the recrystallized grains gradually increases with the increasing ram speed, because a higher extrusion speed generates more deformation heat. However, the size, morphology, amount, and distribution of the second-phase particles are nearly identical in all the extruded sheets. As the ram speed increases from 1 to 10 mm/s, the tensile yield strength of the extruded material decreases from 205 to 125 MPa, which is attributed to the decrease in the grain-boundary hardening effect caused by the grain coarsening. The tensile elongation increases from 13.0% at 1 mm/s to 15.1% at 4 mm/s, and then greatly decreases to 2.9% at 10 mm/s. The drastic ductility degradation of the sheets extruded at the ram speeds larger than 7 mm/s is due to the formation of relatively coarse internal cracks in the material during extrusion. [ABSTRACT FROM AUTHOR]

The combined addition of small amounts of Ca and Y to Mg–Al–Zn alloys has recently been found to greatly improve the ignition resistance, corrosion resistance, and mechanical properties of these alloys. However, Mg–Al–Zn–Ca–Y alloys with high Al content show poor extrudability, which is an obstacle to their use as extruded components in industrial applications. This study aims to improve the extrudability of a Mg–Al–Zn–Ca–Y alloy through the addition of a small amount of mischmetal (MM). To this end, a trace amount (0.5 wt%) of Ce-rich MM is added to a Mg–9Al–0.8Zn–0.9Ca–0.6Y (AZXW9110) alloy. MM addition leads to significant grain refinement of the homogenized billet, from 326 to 180 μm. When the MM-added alloy is extruded into a sheet at 350 °C with an extrusion ratio of 22.9, the maximum ram speed at which it is extrudable without the occurrence of hot cracking is 12 mm/s, substantially higher than the 2 mm/s possible without MM addition. The Ce and La atoms decomposed from the MM are dissolved in the Mg17Al12, Al8Mn4Y, Al2Ca, and Al2Y phases, apparently leading to an increase in the thermal stability of the phases and, consequently, to an improvement in the AZXW9110 alloy's extrudability. At ram speeds above 2 mm/s, many small-sized cracks form at the edges of the extruded AZXW9110–0.5MM sheets. As the ram speed increases up to 6 mm/s, the number density of edge cracks gradually increases while their average spacing decreases, but beyond 6 mm/s both remain almost unchanged. [ABSTRACT FROM AUTHOR]

Until now, SnO2 nanowires have been directly grown on alumina substrates with Au or Au-coated Pt electrodes by a thermal evaporation method using Sn or SnO2 powders under vacuum. However, in this study, SnO2 nanowires were successfully synthesized on the Pt phase of an alumina substrate by a thermal evaporation method using dibutyltin oxide [DBTO, (C4H9)2SnO] even at atmospheric pressure, resulting in nanowire networks between the Pt phases. Ar with 1% O2 was used as carrier gas with a flow rate of 100 mL/min at 900 °C (heating rate of 25 °C/min). The SnO2 nanowires consisted of straight and branched nanowires, and exhibited a SnO2 phase with a tetragonal structure. Both the DBTO and evaporation temperature play an important role on the synthesis of SnO2 nanowires at atmospheric pressure. The SnO2 nanowire sensor fabricated by an evaporation method showed a sensor response of ~ 500 for 0.05 ppm of NO2, being ~ 10 times greater than that of a SnO2 nanoparticle sensor. Furthermore, the SnO2 nanowire sensor showed excellent repeatability and selectivity for NO2 in the presence of SO2, Cl2, and H2S. [ABSTRACT FROM AUTHOR]

Purpose: Under physiologic conditions, the binding of erythropoietin-producing hepatocellular (Eph) A2 receptor and its ligand ephrinA1 results in decreased EphA2 level and tumor suppression. However, EphA2 and ephrinA1 are highly expressed in human cancers including gastric adenocarcinoma. In this study, we tested our hypothesis that cancer-associated fibroblasts (CAFs) promote gastric tumorigenesis through EphA2 signaling in a ligand-independent manner.Methods: Expression of EphA2 protein in primary tumor tissues of 91 patients who underwent curative surgery for gastric adenocarcinoma was evaluated by immunohistochemistry and western blotting. Conditioned medium of cancer-associated fibroblasts (CAF-CM) was used to evaluate the tumorigenic effect of CAFs on gastric cancer cell lines. Epithelial-mesenchymal transition (EMT), cell proliferation, migration, and invasion were assessed. EphrinA1-Fc ligand was used to determine the suppressor role of EphA2 receptor-ligand binding.Results: CAF-CM-induced EMT and promoted cancer cell motility even without cell-cell interaction. Treatment with a selective EphA2 inhibitor (ALW-II-41-27) or EphA2-targeted siRNA markedly reduced CAF-CM-induced gastric tumorigenesis. EphrinA1-Fc ligand treatment showing ligand-dependent tumor suppression diminished the EphA2 expression and EMT progression. In contrast, ephrinA1-targeted siRNA did not significantly affect CAF-CM-mediated increases in EphA2 expression and EMT progression. Treatment with VEGF showed effects like CAF-CM in terms of EphA2 activation and EMT progression.Conclusion: CAFs may contribute to gastric tumorigenesis by activating EphA2 signaling pathway in a ligand-independent manner. Our results suggest that ligand-independent activation of EphA2 was triggered by VEGF released from CAF-CM. Our result may partially explain why ligand-dependent tumor suppressor roles of EphA2 are not evident in gastric cancer despite the prominent level of ephrinA1. [ABSTRACT FROM AUTHOR]

Two series of water-soluble metalloporphyrin-cored amphiphilic star block copolymers were synthesized by controlled radical polymerizations such as atom transfer radical polymerization (ATRP) and reversible addition fragmentation chain transfer (RAFT), which gave eight amphiphilic block copolymer arm chains consisting of poly(n-butyl acrylate-b-poly(ethylene glycol) methyl ether methacylate) (PnBA-b-PEGMEMA, Mn,GPC = 78,000, Mw/Mn = 1.2, 70 wt% of PPEGMEMA) and poly(styrene-b-2-dimethylamino ethyl acrylate) (PS-b-PDMAEA, Mn,GPC = 83,000, Mw/Mn = 1.2, 67 wt% of PDMAEA), yielding porphyrin(Pd)-(PnBA-b-PPEGMEMA)8 and porphyrin(Pd)-(PS-b-PDMAEA)8, respectively. Obtained metalloporphyrin polymer photocatalysts were homogeneously solubilized in water to apply to the removal of chlorophenols in water, and was distinguished from conventional water-insoluble small molecular metalloporphyrin photocatalysts. Notably, we found that the water-soluble star block copolymers with hydrophobic-hydrophilic core-shell structures more effectively decomposed the chlorophenol, 2,4,6-trichlorophenol (2,4,6-TCP), in water under visible light irradiation (k = 1.39 h−1, t1/2 = 0.5 h) in comparison to the corresponding water-soluble star homopolymer, because the hydrophobic core near the metalloporphyrin effectively captured and decomposed the hydrophobic chlorophenols in water. [ABSTRACT FROM AUTHOR]

Objective: To investigate the quality of images reconstructed with adaptive statistical iterative reconstruction V (ASIR-V), using pediatric head CT protocols.Methods: A phantom was scanned at decreasing 20% mA intervals using our standard pediatric head CT protocols. Each study was then reconstructed at 10% ASIR-V intervals. After the phantom study, we reduced mA by 10% in the protocol for <3-year-old patients and applied 30% ASIR-V and by 30% in the protocol for 3- to 15-year-old patients and applied 40% ASIR-V.Results: Increasing the percentage of ASIR-V resulted in lower noise and higher contrast-to-noise ratio (CNR) and preserved spatial resolution in the phantom study. Compared to a conventional-protocol, reduced-dose protocol with ASIR-V achieved 12.8% to 34.0% of dose reduction and showed images of lower noise (9.22 vs. 10.73, P = 0.043) and higher CNR in different levels (centrum semiovale, 2.14 vs. 1.52, P = 0.003; basal ganglia, 1.46 vs. 1.07, P = 0.001; and cerebellum, 2.18 vs. 1.33, P < 0.001). Qualitative analysis showed higher gray-white matter differentiation and sharpness and preserved overall diagnostic quality in the images with ASIR-V.Conclusions: Use of ASIR-V allowed a 12.8% to 34.0% dose reduction in each age group with potential to improve image quality.Key Points: • It is possible to reduce radiation dose and improve image quality with ASIR-V. • We improved noise and CNR and decreased radiation dose. • Sharpness improved with ASIR-V. • Total radiation dose was decreased by 12.8% to 34.0%. [ABSTRACT FROM AUTHOR]

Heteroleptic ruthenium-complexed ladder-like structured polysilsesquioxane (LPSQ-Ru) was synthesized by post coordination reaction of bidentate ligand side chains in LPSQ with reactive Ru(II) complexes, which was well characterized by H and Si NMR, FT-IR, and spectroscopic techniques. The photophysical properties of LPSQ-Ru were examined by UV and PL analyses in both solution and solid states, comparing to analogous polymers of ruthenium-complexed polystyrene (PS-Ru). Obtained absorptions of LPSQ-Ru and PS-Ru were broadened ranging from 390-490 nm regardless of the states. However, LPSQ-Ru exhibited higher and shaper PL emission spectrum in comparison to that of PS-Ru, particularly in the solid state, because Ru-complexes in LPSQ were much effectively isolated, preventing their aggregations due to the rigid double strained siloxane backbone. This extinguished photophysical property in LPSQ-Ru kept after intensive thermal treatment at 250 °C for 90 min, which was not achieved in PS-Ru (~5-fold decrease). These differences originated from the backbone structures were also appeared in electrochemical properties in the solid states. [ABSTRACT FROM AUTHOR]

A reliable analytical method based on high-performance liquid chromatography-ultraviolet detection was established for the determination of oleanonic acid (OA) content in Chios gum mastic (CGM). A simple method involving methanol extraction of CGM powder followed by basification and ether extraction was developed to isolate the triterpenic fraction including OA. The triterpenic fraction was chromatographed on a Phenomenex Gemini C column (150 × 4.6 mm, 5 µm) under a simple gradient elution of a mobile phase containing acetonitrile and water at a flow rate of 1.0 mL min. The detection wavelength was set at 210 nm. Good linearity was achieved in the range of 100.0-1000.0 μg mL with r > 0.9993, and the limit of quantification was 32.22 μg mL. Accuracy measured at three concentration levels was in the range of 93.72-99.56%, while intra-day and inter-day precisions estimated using both OA standard and CGM samples were no more than 2.83 and 4.57% RSD, respectively. Finally, this method was applied to real CGM samples from various batches, revealing that the OA contents were between 88.13 and 100.83 μg mg. These results suggest that the current method can be applied as an efficient analytical method for quality control of CGM. [ABSTRACT FROM AUTHOR]

Phosphatidylinositol 3-kinase (PI3K) plays an important role in the metabolic actions of insulin and is required for adipogenesis. Regulatory subunit 1 of PI3K (PIK3R1) is a critical component of the PI3K signaling pathway. Peroxisome proliferator-activated receptor gamma (PPARγ) is a key regulator of adipogenesis. Although the PPARγ agonist rosiglitazone induces the expression of PIK3R1, the transcriptional regulation of PIK3R1 in adipocytes remains unknown. In this study, we investigated whether PIK3R1 is a direct target of PPARγ. The level of PIK3R1 expression in 3T3-L1 cells was increased after the induction of adipocyte differentiation and was also induced by overexpression of PPARγ. Furthermore, the upregulation of PPARγ-mediated PIK3R1 expression enhanced the insulin-stimulated AKT activation in 3T3-L1 cells. Two putative peroxisome proliferator response elements (PPREs) in the PIK3R1 promoter were identified as PPARγ binding sites. By chromatin immunoprecipitation, we observed that PPARγ interacts with the two PPRE regions of the PIK3R1 promoter in mature adipocytes. In addition, luciferase reporter assays showed that the −1183/−1161 and −573/−551 regions of the PIK3R1 promoter contain essential elements for PPARγ binding. Taken together, these results suggest that PPARγ is essential for the transcriptional activity of PIK3R1 during adipogenesis. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is the most common arrhythmia. Gain-of-function mutations in KCNQ1, the pore-forming α-subunit of the slow delayed rectifier K current ( I) channel, have been associated with AF. The purpose of this study was functional assessment of a mutation in KCNQ1 identified in a family with persistent AF and sinus bradycardia. We investigated whether this KCNQ1 missense mutation could form the genetic basis for AF and bradycardia simultaneously in this family. Sanger sequencing in a family with hereditary persistent AF identified a novel KCNQ1 variant (V241F) in a highly conserved region of S4 domain. The proband and her son developed bradycardia and persistent AF in an age-dependent fashion. The other son was a mutation carrier but he showed sinus bradycardia and not AF. Whole-cell patch clamp electrophysiology showed that V241F mutation in KCNQ1 shifted the activation curve to the left and dramatically slowed deactivation, leading to a constitutively open-like phenotype. Computer modeling showed that V241F would slow pacemaker activity. Also, simulations of atrial excitation predicted that V241F results in extreme shortening of action potential duration, possibly resulting in AF. Our study indicates that V241F might cause sinus bradycardia by increasing I. Additionally, V241F likely shortens atrial refractoriness to promote a substrate for reentry. KCNQ1 mutations have previously been described in AF, yet this is the first time a mutation in KCNQ1 is associated with age-dependent bradycardia and persistent AF. This finding further supports the hypothesis that sinus node dysfunction contributes to the development of AF. [ABSTRACT FROM AUTHOR]

Plasma profile of niflumic acid following oral administration of talniflumate tablets (Somalgen) was compared to that of niflumic acid tablets in man. Plasma niflumic acid was assayed by HPLC method. Plasma niflumic acid profile from the talniflumate tablets was similar to that from the niflumic acid tablets resulting in no differences in AUC, C , t and MRT. It demonstrates that talniflumate is a prodrug of niflumic acid, and undergoes extensive first-pass biotransformation to niflumic acid. However, plasma niflumic acid concentration at 30 min after talniflumate dosing was significantly (p<0.05) higher than that of niflumic acid dosing. The more potent analgesic activity of talniflumate than niflumic acid might be related to this higher plasma drug concentration at the earlier phase. Considering that talniflumate is less irritant to gastrointestinal mucosa than niflumic acid, talniflumate seems to be advantageous over niflumic acid in therms of activity and side effects. [ABSTRACT FROM AUTHOR]

Many emerging technologies are reliant on circulating cell-free DNA (cfDNA) and cell-free RNA (cfRNA) applications in the clinic. However, the impact of diurnal cycles or daily meals on circulating analytes are poorly understood and may be confounding factors when developing diagnostic platforms. To begin addressing this knowledge gap, we obtained plasma from four healthy donors serially sampled five times during 12 h in a single day. For all samples, we measured concentrations of cfDNA and cfRNA using both bulk measurements and gene-specific digital droplet PCR. We found no significant variation attributed to blood draw number for the cfDNA or cfRNA. This indicated that natural diurnal cycles and meal consumption do not appear to significantly affect abundance of total cfDNA, total cfRNA, or our two selected cfRNA transcripts. Conversely, we observed significant variation between individual donors for cfDNA and one of the cfRNA transcripts. The results of this work suggest that it will be important to consider patient-specific baselines when designing reliable circulating cfDNA or cfRNA clinical assays. [ABSTRACT FROM AUTHOR]

[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Pathogenic variants in the human SCN5A gene encoding the a-subunit of the principle Na+ channel (Nav1.5) are associated with long QT syndrome (LQTS) 3. LQT3 patients display variable responses to Na+ channel blockers demanding for the development of variant-specific therapeutic strategies. Here we performed a combined electrophysiological analysis with in silico simulation of variant channel to elucidate mechanisms of therapeutic responsiveness. We identified a novel SCN5A variant (A1656D) in a LQTS patient with a distinct response to mexiletine resulting in suppression of non-sustained ventricular tachycardia and manifestation of premature atrial contraction. Patch clamp analysis revealed that A1656D variant exerted gain-of-function effects including hyperpolarizing shift of the voltage-dependence of activation, depolarizing shift in the voltage-dependence of inactivation, and slowing of fast inactivation. Among ranolazine, flecainide, and mexiletine, only mexiletine restored inactivation kinetics of A1656D currents. In silico simulation to assess the effect of A1656D variant on ventricular cardiac cell excitation predicted a prolonged action potential which is consistent with the prolonged QT and non-sustained ventricular tachycardia of the patient. It also predicted that only mexiletine suppressed the prolonged action potential of human ventricular myocytes expressing A1656D. These data elucidate the underlying mechanism of the distinct response to mexiletine in this patient. [ABSTRACT FROM AUTHOR]

Genetically deregulated tumor cells generate vascular channels by vasculogenic mimicry (VM) that is independent of endothelial blood vessels. The morphological characteristics of VM and the role of EphA2 in the formation of VM were evaluated in 144 clinical samples of gastric adenocarcinoma and AGS gastric cancer cell line. It has long been believed that VM consists of PAS-positive basement membrane and CD31/CD34-negative cells. Interestingly, we found that the luminal surface of gastric tumor cells that form VM channels showed PAS-positive reaction, and that the involvement of CD31/CD34-positive tumor cells in the formation of VM channels. Highly aggressive tumor cells that formed VM were found to express CD31 or CD34, implicating the angiogenic and vasculogenic potential of the genetically deregulated tumor cells. VM occurrence was positively correlated with high expression of EphA2 in our patient cohort, and the indispensable role of EphA2 in VM formation was identified by gene silencing in AGS cells. We also report that Epstein-Barr virus (EBV)-positive tumor cells were involved in the formation of VM channels in EBV-associated gastric cancer samples. Overall, our results suggest that EphA2 signaling promotes tumor metastasis by inducing VM formation during gastric tumorigenesis. [ABSTRACT FROM AUTHOR]

Dysregulation of Ca2+/calmodulin-dependent protein kinase (CaMK)II is closely linked with myocardial hypertrophy and heart failure. However, the mechanisms that regulate CaMKII activity are incompletely understood. Here we show that protein arginine methyltransferase 1 (PRMT1) is essential for preventing cardiac CaMKII hyperactivation. Mice null for cardiac PRMT1 exhibit a rapid progression to dilated cardiomyopathy and heart failure within 2 months, accompanied by cardiomyocyte hypertrophy and fibrosis. Consistently, PRMT1 is downregulated in heart failure patients. PRMT1 depletion in isolated cardiomyocytes evokes hypertrophic responses with elevated remodeling gene expression, while PRMT1 overexpression protects against pathological responses to neurohormones. The level of active CaMKII is significantly elevated in PRMT1-deficient hearts or cardiomyocytes. PRMT1 interacts with and methylates CaMKII at arginine residues 9 and 275, leading to its inhibition. Accordingly, pharmacological inhibition of CaMKII restores contractile function in PRMT1-deficient mice. Thus, our data suggest that PRMT1 is a critical regulator of CaMKII to maintain cardiac function. The mechanisms that regulate the activity of Ca2 +/calmodulin-dependent protein kinase II (CaMKII) in the context of heart failure are incompletely understood. Here the authors show that protein arginine methyltransferase 1 (PRMT1) prevents cardiac hyperactivation of CaMKII and heart failure development by methylating CaMKII at arginine residues 9 and 275. [ABSTRACT FROM AUTHOR]

Following uncontrolled proliferation, a subset of primary tumour cells acquires additional traits/mutations to trigger phenotypic changes that enhance migration and are hypothesized to be the initiators of metastasis. This study reveals an adaptive mechanism that harnesses synergistic paracrine signalling via IL-6/8, which is amplified by cell proliferation and cell density, to directly promote cell migration. This effect occurs in metastatic human sarcoma and carcinoma cells- but not in normal or non-metastatic cancer cells-, and likely involves the downstream signalling of WASF3 and Arp2/3. The transcriptional phenotype of high-density cells that emerges due to proliferation resembles that of low-density cells treated with a combination of IL-6/8. Simultaneous inhibition of IL-6/8 receptors decreases the expression of WASF3 and Arp2/3 in a mouse xenograft model and reduces metastasis. This study reveals a potential mechanism that promotes tumour cell migration and infers a strategy to decrease metastatic capacity of tumour cells. [ABSTRACT FROM AUTHOR]

The inward rectifier Kir2.1 current (IKir2.1) was reported to be facilitated by fluid flow. However, the mechanism underlying this facilitation remains uncertain. We hypothesized that during K+ influx or efflux, [K+] adjacent to the outer mouth of the Kir2.1 channel might decrease or increase, respectively, compared with the average [K+] of the bulk extracellular solution, and that fluid flow could restore the original [K+] and result in the apparent facilitation of IKir2.1. We recorded the IKir2.1 in RBL-2H3 cells and HEK293T cells that were ectopically over-expressed with Kir2.1 channels by using the whole-cell patch-clamp technique. Fluid-flow application immediately increased the IKir2.1, which was not prevented by either the pretreatment with inhibitors of various protein kinases or the modulation of the cytoskeleton and caveolae. The magnitudes of the increases of IKir2.1 by fluid flow were driving force-dependent. Simulations performed using the Nernst-Planck mass equation indicated that [K+] near the membrane surface fell markedly below the average [K+] of the bulk extracellular solution during K+ influx, and, notably, that fluid flow restored the decreased [K+] at the cell surface in a flow rate-dependent manner. These results support the 'convection-regulation hypothesis' and define a novel interpretation of fluid flow-induced modulation of ion channels. [ABSTRACT FROM AUTHOR]