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1.
Proc Natl Acad Sci U S A ; 121(3): e2314797121, 2024 Jan 16.
Article in English | MEDLINE | ID: mdl-38194452

ABSTRACT

Assessing the ergodicity of graphene liquid cell electron microscope measurements, we report that loop states of circular DNA interconvert reversibly and that loop numbers follow the Boltzmann distribution expected for this molecule in bulk solution, provided that the electron dose is low (80-keV electron energy and electron dose rate 1-20 e- Å-2 s-1). This imaging technique appears to act as a "slow motion" camera that reveals equilibrated distributions by imaging the time average of a few molecules without the need to image a spatial ensemble.


Subject(s)
Electrons , Graphite , Microscopy, Electron , Motion , Nucleic Acid Conformation
2.
Small ; 20(31): e2400518, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38747079

ABSTRACT

Motivated by the increasing cost, environmental concerns, and limited availability of Co, researchers are actively seeking alternative cathode materials for lithium-ion batteries. A promising strategy involves structure-modified materials, such as a NiMn core/shell system. This design leverages the high energy density of a Ni-rich core while employing an Mn-rich shell to enhance interfacial stability by suppressing unwanted reactions with the electrolyte. This approach offers improved cycling stability and reduced reliance on Co. However, the interdiffusion of Mn ions between the core and shell remains a significant challenge during synthesis. This work presents a facile approach to address the issue of Mn interdiffusion in core/shell cathode materials. The study demonstrates that partial oxidation of the precursor during the drying stage effectively enhances the Mn oxidation state. This strategy successfully suppresses Mn interdiffusion during subsequent calcination, leading to the preservation of the core/shell architecture in the final cathode material. This optimized structure mitigates interfacial reactions, enhances chemomechanical properties, and reduces crosstalk, a major contributor to rollover failure. This work presents a novel approach for synthesizing high-performance core/shell cathode materials for next-generation lithium-ion batteries.

3.
Biomacromolecules ; 25(3): 2024-2032, 2024 Mar 11.
Article in English | MEDLINE | ID: mdl-38393758

ABSTRACT

α-Glucan microparticles (GMPs) have significant potential as high-value biomaterials in various industries. This study proposes a bottom-up approach for producing GMPs using four amylosucrases from Bifidobacterium sp. (BASs). The physicochemical characteristics of these GMPs were analyzed, and the results showed that the properties of the GMPs varied depending on the type of enzymes used in their synthesis. As common properties, all GMPs exhibited typical B-type crystal patterns and poor colloidal dispersion stability. Interestingly, differences in the physicochemical properties of GMPs were generated depending on the synthesis rate of linear α-glucan by the enzymes and the degree of polymerization (DP) distribution. Consequently, we found differences in the properties of GMPs depending on the DP distribution of linear glucans prepared with four BASs. Furthermore, we suggest that precise control of the type and characteristics of the enzymes provides the possibility of producing GMPs with tailored physicochemical properties for various industrial applications.


Subject(s)
Bifidobacterium , Glucans , Guanosine Monophosphate , Thionucleotides , Glucans/chemistry , Glucosyltransferases
4.
Eur Radiol ; 34(4): 2233-2243, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37731096

ABSTRACT

OBJECTIVE: We aimed to compare the image quality and focal lesion detection ability of hepatobiliary phase (HBP) images obtained using compressed sensing (CS) and controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) in patients with liver cirrhosis. MATERIALS AND METHODS: We retrospectively included 244 gadoxetic acid-enhanced liver MRI from 244 patients with cirrhosis obtained by two HBP images using CS and CAIPIRINHA from July 2020 to December 2020. The optimized resolution and scan time for CS-HBP and CAIPIRINHA-HBP were 0.9 × 0.9 × 1.5 mm3 and 15 s and 1.3 × 1.3 × 3 mm3 and 16 s, respectively. We compared the image quality between the two sets of images in 244 patients and focal lesion (n = 294) analyses for 112 patients. RESULTS: CS-HBP showed comparable overall image quality (3.7 ± 0.9 vs. 3.6 ± 0.8, p = 0.680), superior liver edge sharpness (3.9 ± 0.6 vs. 3.6 ± 0.5, p < 0.001), and fewer respiratory motion artifacts (4.0 ± 0.7 vs. 3.8 ± 0.5, p < 0.001), but higher non-respiratory artifacts (3.4 ± 0.7 vs. 3.6 ± 0.6, p < 0.001) and subjective image noise (3.5 ± 0.8 vs. 3.6 ± 0.7, p = 0.014) than CAIPIRINHA-HBP. CS-HBP showed a higher signal-to-noise ratio in the liver than CAIPIRINHA-HBP (20.9 ± 9.0 vs. 18.9 ± 7.1, p = 0.008). The pooled sensitivity, specificity, and AUC were 90.0%, 77.5%, and 0.84 for CS-HBP and 73.5%, 82.4%, and 0.78 for CAIPIRINHA-HBP, respectively. CONCLUSIONS: CS-HBP showed better focal lesion detection ability, comparable overall image quality, and fewer respiratory motion artifacts, but higher non-respiratory artifacts and noise compared to CAIPIRINHA-HBP. Thus, CS-HBP could be recommended for liver MRI in patients with cirrhosis to improve diagnostic performance. CLINICAL RELEVANCE STATEMENT: Thin-slice CS-HBP may be useful for detecting sub-centimeter hepatocellular carcinoma in cirrhotic patients with Child-Pugh classification A while maintaining comparable subjective image quality. KEY POINTS: • Compared with controlled aliasing in parallel imaging results in higher acceleration, compressed sensing hepatobiliary phase yielded thinner slices and shorter scan time at a higher accelerating factor. • Compressed sensing hepatobiliary phase showed comparable overall image quality, superior liver edge sharpness, and fewer respiratory motion artifacts, but higher non-respiratory artifacts and subjective image noise than controlled aliasing in parallel imaging results in higher acceleration-hepatobiliary phase. • Compressed sensing hepatobiliary phase can detect sub-centimeter hepatocellular carcinoma in cirrhotic patients with Child-Pugh classification A.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Contrast Media , Retrospective Studies , Imaging, Three-Dimensional/methods , Gadolinium DTPA , Magnetic Resonance Imaging/methods , Acceleration , Liver Cirrhosis/complications , Liver Cirrhosis/diagnostic imaging , Liver Neoplasms/complications , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/pathology , Artifacts , Image Enhancement/methods
5.
Somatosens Mot Res ; 41(1): 48-55, 2024 Mar.
Article in English | MEDLINE | ID: mdl-36721377

ABSTRACT

PURPOSE AND METHOD: The purpose of this study was to determine the changes in the Blood Oxygen Level Dependent signal of Primary somatosensory area (S1) and Brodmann area 3 (BA3) per finger and phalanx in comparison to the activation voxel when 250 Hz vibratory stimulation with high sensitivity for the Pacinian corpuscle was given to the four fingers and three phalanges. RESULTS: The result of analyzing the activation voxel showed a significant difference for S1 per finger and phalanx, but for BA3, no significant difference was observed despite a similar trend to S1. In contrast, the activation intensity (BOLD) displayed a significant difference for S1 per finger and phalanx and for BA3, where the activation voxel had no significant variation. In addition, while the result of S1 did not indicate whether the index or the little fingers had the highest sensitivity based on the BOLD signal per finger, the result of BA3 marked the strongest BOLD signal for the little finger as a response to 250 Hz vibratory stimulation. The activation intensity per phalanx was the highest for the intermediate phalanx for S1 and BA3, which was in line with a previous study comparing the activation voxel. CONCLUSIONS: The method based on the intensity of the nerve activation is presumed to have high sensitivity as the signal intensity is monitored within a specific, defined area. Thus, for the extraction of brain activation patterns of micro-domains, such as BA3, monitoring the BOLD signal that reflects the nerve activation intensity more sensitively is likely to be advantageous.


Subject(s)
Magnetic Resonance Imaging , Somatosensory Cortex , Somatosensory Cortex/physiology , Magnetic Resonance Imaging/methods , Fingers/innervation , Brain Mapping/methods
6.
Nano Lett ; 23(8): 3645-3652, 2023 Apr 26.
Article in English | MEDLINE | ID: mdl-36876977

ABSTRACT

The shaping of matter into desired nanometric structures with on-demand functionalities can enhance the miniaturization of devices in nanotechnology. Herein, strong light-matter interaction was used as an optical lithographic tool to tailor two-dimensional (2D) matter into nanoscale architectures. We transformed 2D black phosphorus (BP) into ultrafine, well-defined, beyond-diffraction-limit nanostructures of ten times smaller size and a hundred times smaller spacing than the incident, femtosecond-pulsed light wavelength. Consequently, nanoribbons and nanocubes/cuboids scaling tens of nanometers were formed by the structured ablation along the extremely confined periodic light fields originating from modulation instability, the tailoring process of which was visualized in real time via light-coupled in situ transmission electron microscopy. The current findings on the controllable nanoscale shaping of BP will enable exotic physical phenomena and further advance the optical lithographic techniques for 2D materials.

7.
World J Microbiol Biotechnol ; 40(9): 261, 2024 Jul 08.
Article in English | MEDLINE | ID: mdl-38972914

ABSTRACT

The fecal microbiota of two healthy adults was cultivated in a medium containing commercial fructooligosaccharides [FOS; 1-kestose (GF2), nystose (GF3), and 1F-fructofuranosylnystose (GF4)]. Initially, the proportions of lactobacilli in the two feces samples were only 0.42% and 0.17%; however, they significantly increased to 7.2% and 4.8%, respectively, after cultivation on FOS. Most FOS-utilizing isolates could utilize only GF2; however, Lacticaseibacillus paracasei strain Lp02 could fully consume GF3 and GF4 too. The FOS operon (fosRABCDXE) was present in Lc. paracasei Lp02 and another Lc. paracasei strain, KCTC 3510T, but fosE was only partially present in the non-FOS-degrading strain KCTC 3510T. In addition, the top six upregulated genes in the presence of FOS were fosABCDXE, particularly fosE. FosE is a ß-fructosidase that hydrolyzes both sucrose and all three FOS. Finally, a genome-based analysis suggested that fosE is mainly observed in Lc. paracasei, and only 13.5% (61/452) of their reported genomes were confirmed to include it. In conclusion, FosE allows the utilization of FOS, including GF3 and GF4 as well as GF2, by some Lc. paracasei strains, suggesting that this species plays a pivotal role in FOS utilization in the human gut.


Subject(s)
Feces , Gastrointestinal Microbiome , Lacticaseibacillus paracasei , Oligosaccharides , beta-Fructofuranosidase , Humans , Oligosaccharides/metabolism , Feces/microbiology , Lacticaseibacillus paracasei/metabolism , Lacticaseibacillus paracasei/genetics , beta-Fructofuranosidase/metabolism , beta-Fructofuranosidase/genetics , Adult , Operon , Trisaccharides/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism
8.
Omega (Westport) ; : 302228241279881, 2024 Sep 02.
Article in English | MEDLINE | ID: mdl-39222379

ABSTRACT

This study aims to validate the Korean version of the Revised Prolonged Grief Disorder scale (PG-13-R-K) by exploring the psychometric properties of the revised Prolonged Grief Disorder scale in bereaved South Korean adults. A total of 694 bereaved individuals who had experienced the loss of a close person for a duration ranging from 12 to 24 months were included in this study and randomly divided into two separate datasets to conduct factor analyses. The results of both EFA and CFA revealed a single-factor structure for the PG-13-R-K. Moreover, the results of reliability and validity tests showed adequate internal consistency and concurrent validity. These findings suggest that the PG-13-R-K is a reliable and valid tool for assessing PGD symptoms among bereaved Korean adults. The limitations and implications of this study are thoroughly examined and discussed.

9.
Inflamm Res ; 72(10-11): 1981-1997, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37770568

ABSTRACT

BACKGROUND: Classically activated M1 macrophages, characterized by aberrant glycolysis and secretion of inflammatory cytokines, play pivotal roles in inflammatory diseases, including inflammatory bowel disease (IBD). Recently, sodium-glucose co-transporter 2 (SGLT2) inhibitors were shown to suppress Na+/H+ exchanger 1 (NHE1) and Na+/Ca2+ exchanger 1 (NCX1) activity, regulating downstream intracellular Ca2+ concentrations in cardiomyocytes. However, whether SGLT2 inhibitors regulate M1 macrophage polarization by downregulating NHE1 and NCX1 remains unknown. METHODS: We analyzed cellular responses to SGLT2 inhibitors using mouse bone marrow-derived macrophages and peritoneal macrophages treated with lipopolysaccharide (LPS). To induce IBD, we used a dextran sulfate sodium salt-induced colitis mouse model. RESULTS: We observed that NHE1 and NCX1 were overexpressed in LPS-treated macrophages, leading to M1 macrophage polarization. Mechanistically, NHE1 and NCX1-mediated Ca2+ accumulation in the macrophage resulted in enhanced glycolysis by promoting PI3K/AKT/mTORC1 signaling. SGLT2 inhibitors suppressed both the expression levels and activities of NHE1 and NCX1, and consequently downregulated PI3K/AKT/mTORC1 signaling and glycolysis in LPS-treated macrophages. We observed inhibition of LPS-stimulated M1 polarization and cytokine production by SGLT2 inhibitors in vitro, ex vivo, and in an IBD mouse model. CONCLUSIONS: NHE1 promotes M1 macrophage polarization and SGLT2 inhibitors are a novel strategy to treat M1 macrophage-mediated inflammatory diseases, including IBD.


Subject(s)
Inflammatory Bowel Diseases , Sodium-Glucose Transporter 2 Inhibitors , Animals , Mice , Lipopolysaccharides/pharmacology , Lipopolysaccharides/metabolism , Sodium-Glucose Transporter 2 Inhibitors/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Inflammatory Bowel Diseases/drug therapy , Inflammatory Bowel Diseases/metabolism , Macrophages/metabolism , Disease Models, Animal , Mechanistic Target of Rapamycin Complex 1/metabolism
10.
J Chem Phys ; 159(5)2023 Aug 07.
Article in English | MEDLINE | ID: mdl-37526153

ABSTRACT

Electron energy-loss spectroscopy (EELS) can measure similar information to x-ray, UV-Vis, and IR spectroscopies but with atomic resolution and increased scattering cross-sections. Recent advances in electron monochromators have expanded EELS capabilities from chemical identification to the realms of synchrotron-level core-loss measurements and to low-loss, 10-100 meV excitations, such as phonons, excitons, and valence structures. EELS measurements are easily correlated with electron diffraction and atomic-scale real-space imaging in a transmission electron microscope (TEM) to provide detailed local pictures of quasiparticle and bonding states. This perspective provides an overview of existing high-resolution EELS (HR-EELS) capabilities while also motivating the powerful next step in the field-ultrafast EELS in a TEM. Ultrafast EELS aims to combine atomic-level, element-specific, and correlated temporal measurements to better understand spatially specific excited-state phenomena. Ultrafast EELS measurements also add to the abilities of steady-state HR-EELS by being able to image the electromagnetic field and use electrons to excite photon-forbidden and momentum-specific transitions. We discuss the technical challenges ultrafast HR-EELS currently faces, as well as how integration with in situ and cryo measurements could expand the technique to new systems of interest, especially molecular and biological samples.

11.
Mar Drugs ; 21(9)2023 Aug 26.
Article in English | MEDLINE | ID: mdl-37755082

ABSTRACT

The protein extract of Ulva australis hydrolyzed with Alcalase and Flavourzyme was found to have multi-functional properties, including total antioxidant capacity (TAC), collagenase inhibitory, and antibacterial activities. The #5 fraction (SP5) and #7 fraction (SP7) of U. australis hydrolysate from cation-exchange chromatography displayed significantly high TAC, collagenase inhibitory, and antibacterial effects against Propionibacterium acnes, and only the Q3 fraction from anion-exchange chromatography displayed high multi-functional activities. Eight of 42 peptides identified by MALDI-TOF/MS and Q-TOF/MS/MS were selected from the results for screening with molecular docking on target proteins and were then synthesized. Thr-Gly-Thr-Trp (TGTW) displayed ABTS [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)] radical scavenging activity. The effect of TAC as Trolox equivalence was dependent on the concentration of TGTW. Asn-Arg-Asp-Tyr (NRDY) and Arg-Asp-Arg-Phe (RDRF) exhibited collagenase inhibitory activity, which increased according to the increase in concentration, and their IC50 values were 0.95 mM and 0.84 mM, respectively. Peptides RDRF and His-Ala-Val-Tyr (HAVY) displayed anti-P. Acnes effects, with IC50 values of 8.57 mM and 13.23 mM, respectively. These results suggest that the U. australis hydrolysate could be a resource for the application of effective nutraceuticals and cosmetics.

12.
Proc Natl Acad Sci U S A ; 117(3): 1283-1292, 2020 01 21.
Article in English | MEDLINE | ID: mdl-31911471

ABSTRACT

Traditional single-molecule methods do not report whole-molecule kinetic conformations, and their adaptive shape changes during the process of self-assembly. Here, using graphene liquid-cell electron microscopy with electrons of low energy at low dose, we show that this approach resolves the time dependence of conformational adaptations of macromolecules for times up to minutes, the resolution determined by motion blurring, with DNA as the test case. Single-stranded DNA molecules are observed in real time as they hybridize near the solid surface to form double-stranded helices; we contrast molecules the same length but differing in base-pair microstructure (random, blocky, and palindromic hairpin) whose key difference is that random sequences possess only one stable final state, but the others offer metastable intermediate structures. Hybridization is observed to couple with enhanced translational mobility and torsion-induced rotation of the molecule. Prevalent transient loops are observed in error-correction processes. Transient melting and other failed encounters are observed in the competitive binding of multiple single-stranded molecules. Among the intermediate states reported here, some were predicted but not observed previously, and the high incidence of looping and enhanced mobility come as surprises. The error-producing mechanisms, failed encounters, and transient intermediate states would not be easily resolved by traditional single-molecule methods. The methods generalize to visualize motions and interactions of other organic macromolecules.

13.
Proc Natl Acad Sci U S A ; 117(47): 29832-29838, 2020 11 24.
Article in English | MEDLINE | ID: mdl-33139569

ABSTRACT

Effective therapies are urgently needed for the SARS-CoV-2/COVID-19 pandemic. We identified panels of fully human monoclonal antibodies (mAbs) from large phage-displayed Fab, scFv, and VH libraries by panning against the receptor binding domain (RBD) of the SARS-CoV-2 spike (S) glycoprotein. A high-affinity Fab was selected from one of the libraries and converted to a full-size antibody, IgG1 ab1, which competed with human ACE2 for binding to RBD. It potently neutralized replication-competent SARS-CoV-2 but not SARS-CoV, as measured by two different tissue culture assays, as well as a replication-competent mouse ACE2-adapted SARS-CoV-2 in BALB/c mice and native virus in hACE2-expressing transgenic mice showing activity at the lowest tested dose of 2 mg/kg. IgG1 ab1 also exhibited high prophylactic and therapeutic efficacy in a hamster model of SARS-CoV-2 infection. The mechanism of neutralization is by competition with ACE2 but could involve antibody-dependent cellular cytotoxicity (ADCC) as IgG1 ab1 had ADCC activity in vitro. The ab1 sequence has a relatively low number of somatic mutations, indicating that ab1-like antibodies could be quickly elicited during natural SARS-CoV-2 infection or by RBD-based vaccines. IgG1 ab1 did not aggregate, did not exhibit other developability liabilities, and did not bind to any of the 5,300 human membrane-associated proteins tested. These results suggest that IgG1 ab1 has potential for therapy and prophylaxis of SARS-CoV-2 infections. The rapid identification (within 6 d of availability of antigen for panning) of potent mAbs shows the value of large antibody libraries for response to public health threats from emerging microbes.


Subject(s)
COVID-19 Serological Testing/methods , COVID-19 Vaccines/immunology , COVID-19/therapy , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibodies, Viral/blood , Antibodies, Viral/immunology , Antibody-Dependent Cell Cytotoxicity , COVID-19 Serological Testing/standards , COVID-19 Vaccines/standards , Chlorocebus aethiops , Cricetinae , Female , Humans , Immunization, Passive/methods , Immunization, Passive/standards , Immunogenicity, Vaccine , Immunoglobulin G/blood , Immunoglobulin G/immunology , Mice , Mice, Inbred BALB C , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Vero Cells , COVID-19 Serotherapy
14.
J Korean Med Sci ; 38(33): e268, 2023 Aug 21.
Article in English | MEDLINE | ID: mdl-37605501

ABSTRACT

BACKGROUND: Unlike gestational diabetic mellitus (GDM), which is strictly managed by most patients and physicians, obesity does not have proper management guidelines, and the importance of its management during pregnancy is often ignored. The aim of this study was to compare maternal and neonatal outcomes according to obesity and GDM, alone or in combination. METHODS: This was a retrospective cohort study of 3,078 consecutive pregnant women who experienced prenatal care and delivery of a live singleton neonate between January 2016 and December 2020 at our institution. Study participants were categorized into 4 mutually exclusive groups, as follows: group 1, no GDM without obesity; group 2, GDM without obesity; group 3, no GDM with obesity; and group 4, GDM with obesity. RESULTS: Compared to group 2, group 3 had higher rates of pre-eclampsia, cesarean section including emergent cesarean section rate. Also, neonates in group 3 were heavier and had lower glucose levels compared to those in group 2. Of note, there was no significant difference in maternal or neonatal outcomes except the rate of large-for-gestational-age (LGA) between group 1 and group 2. Among the GDM groups, group 4 had higher risks for pre-eclampsia, cesarean section, and LGA infant status than group 2. CONCLUSION: Our data showed that obese women without GDM face higher risk of adverse pregnancy outcomes than women with supervised GDM and non-obese women. We also confirmed that adverse pregnancy outcomes associated with GDM were mainly attributable to obesity among women receiving GDM education.


Subject(s)
Diabetes, Gestational , Pre-Eclampsia , Pregnancy , Infant , Infant, Newborn , Female , Humans , Diabetes, Gestational/epidemiology , Cesarean Section , Pre-Eclampsia/epidemiology , Pre-Eclampsia/etiology , Retrospective Studies , Obesity/complications
15.
Sensors (Basel) ; 23(8)2023 Apr 14.
Article in English | MEDLINE | ID: mdl-37112323

ABSTRACT

With the most recent developments in wearable technology, the possibility of continually monitoring stress using various physiological factors has attracted much attention. By reducing the detrimental effects of chronic stress, early diagnosis of stress can enhance healthcare. Machine Learning (ML) models are trained for healthcare systems to track health status using adequate user data. Insufficient data is accessible, however, due to privacy concerns, making it challenging to use Artificial Intelligence (AI) models in the medical industry. This research aims to preserve the privacy of patient data while classifying wearable-based electrodermal activities. We propose a Federated Learning (FL) based approach using a Deep Neural Network (DNN) model. For experimentation, we use the Wearable Stress and Affect Detection (WESAD) dataset, which includes five data states: transient, baseline, stress, amusement, and meditation. We transform this raw dataset into a suitable form for the proposed methodology using the Synthetic Minority Oversampling Technique (SMOTE) and min-max normalization pre-processing methods. In the FL-based technique, the DNN algorithm is trained on the dataset individually after receiving model updates from two clients. To decrease the over-fitting effect, every client analyses the results three times. Accuracies, Precision, Recall, F1-scores, and Area Under the Receiver Operating Curve (AUROC) values are evaluated for each client. The experimental result shows the effectiveness of the federated learning-based technique on a DNN, reaching 86.82% accuracy while also providing privacy to the patient's data. Using the FL-based DNN model over a WESAD dataset improves the detection accuracy compared to the previous studies while also providing the privacy of patient data.


Subject(s)
Artificial Intelligence , Wrist , Humans , Galvanic Skin Response , Wrist Joint , Fitness Trackers
16.
J Biol Chem ; 297(6): 101314, 2021 12.
Article in English | MEDLINE | ID: mdl-34715128

ABSTRACT

Normal physiology relies on the precise coordination of intracellular signaling pathways that respond to nutrient availability to balance cell growth and cell death. The canonical mitogen-activated protein kinase pathway consists of the RAF-MEK-ERK signaling cascade and represents one of the most well-defined axes within eukaryotic cells to promote cell proliferation, which underscores its frequent mutational activation in human cancers. Our recent studies illuminated a function for the redox-active micronutrient copper (Cu) as an intracellular mediator of signaling by connecting Cu to the amplitude of mitogen-activated protein kinase signaling via a direct interaction between Cu and the kinases MEK1 and MEK2. Given the large quantities of molecules such as glutathione and metallothionein that limit cellular toxicity from free Cu ions, evolutionarily conserved Cu chaperones facilitate efficient delivery of Cu to cuproenzymes. Thus, a dedicated cellular delivery mechanism of Cu to MEK1/2 likely exists. Using surface plasmon resonance and proximity-dependent biotin ligase studies, we report here that the Cu chaperone for superoxide dismutase (CCS) selectively bound to and facilitated Cu transfer to MEK1. Mutants of CCS that disrupt Cu(I) acquisition and exchange or a CCS small-molecule inhibitor were used and resulted in reduced Cu-stimulated MEK1 kinase activity. Our findings indicate that the Cu chaperone CCS provides fidelity within a complex biological system to achieve appropriate installation of Cu within the MEK1 kinase active site that in turn modulates kinase activity and supports the development of novel MEK1/2 inhibitors that target the Cu structural interface or blunt dedicated Cu delivery mechanisms via CCS.


Subject(s)
Copper/metabolism , MAP Kinase Kinase 1/metabolism , MAP Kinase Kinase 2/metabolism , Molecular Chaperones/metabolism , Cell Line , Enzyme Activation , Humans , Protein Binding
17.
Biochem Biophys Res Commun ; 599: 134-141, 2022 04 09.
Article in English | MEDLINE | ID: mdl-35182939

ABSTRACT

Metabolic abnormalities are tightly connected to the perturbation of normal brain functions, thereby causing multiple neurodegenerative diseases. The hypothalamus is the master unit that controls the whole-body energy homeostasis. Thus, altered metabolic activity in the hypothalamus could be a crucial clue to better understand the development of metabolic disorders during aging. The current study aimed to investigate the changes in hypothalamic metabolites according to the aging process using gas chromatography-mass spectrometry. We identified that multiple metabolites and neurotransmitters were effectively reduced in the hypothalamus of aged mice. In addition, we observed increased levels of genes linked to the production and utilization of monocarboxylates in the aged hypothalamus, indicating the initiation of metabolic activity to produce alternative nutrient sources. Lastly, we found a reduced number of astrocytes in the hypothalamus of aged mice, suggesting that reduced nutrient availability in the hypothalamus might be associated with the decreased activity of astrocytes during aging. Collectively, the present study suggests that the deterioration of metabolic activities in the hypothalamus might be a primary cause and/or outcome of metabolic diseases associated with the aging process.


Subject(s)
Aging/metabolism , Hypothalamus/metabolism , Metabolome/physiology , Animals , Astrocytes/metabolism , Blood/metabolism , Gene Expression Regulation , Glial Fibrillary Acidic Protein/immunology , Hypothalamus/cytology , Hypothalamus/physiology , Immunohistochemistry/methods , Male , Mice, Inbred C57BL
18.
Int J Mol Sci ; 23(3)2022 Feb 01.
Article in English | MEDLINE | ID: mdl-35163619

ABSTRACT

Classically activated M1 macrophages reprogram their metabolism towards enhanced glycolysis to obtain energy and produce pro-inflammatory cytokines after activation by mammalian target of rapamycin complex 1 (mTORC1) and hypoxia-inducible factor (HIF)-1α. Thus, a strategy that constrains M1 polarization of macrophages via downregulation of glycolysis is essential for treating chronic inflammatory diseases. Cassiae semen has pharmacological activity against various inflammatory diseases. However, it is unclear whether specific compounds within Cassia seeds affect M1 polarization of macrophages. Here, we investigated whether Cassiaside C napthopyrone from Cassiae semen inhibits M1 polarization by downregulating glycolysis. We found that Cassiaside C reduced expression of inducible nitric oxide synthase and cyclooxygenase-2 and the phosphorylation of nuclear factor kappa B, all of which are upregulated in lipopolysaccharide (LPS)/interferon (IFN)-γ-treated Raw264.7 cells and peritoneal macrophages. Moreover, Cassiaside C-treated macrophages showed marked suppression of LPS/IFN-γ-induced HIF-1α, pyruvate dehydrogenase kinase 1, and lactate dehydrogenase A expression, along with downregulation of the phosphoinositide 3-kinases (PI3K)/AKT/mTORC1 signaling pathway. Consequently, Cassiaside C attenuated enhanced glycolysis and lactate production, but rescued diminished oxidative phosphorylation, in M1 polarized macrophages. Thus, Cassiaside C dampens M1 polarization of macrophages by downregulating glycolysis, which could be exploited as a therapeutic strategy for chronic inflammatory conditions.


Subject(s)
Cell Polarity , Glycolysis , Glycosides , Macrophage Activation , Macrophages , Animals , Mice , Gene Expression Regulation , Macrophages/drug effects , Macrophages/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism , Mice, Inbred C57BL , Nitric Oxide Synthase Type II/genetics , Proto-Oncogene Proteins c-akt/metabolism , RAW 264.7 Cells , Signal Transduction , Cell Polarity/drug effects , Glycosides/pharmacology
19.
J Prosthet Dent ; 128(6): 1319.e1-1319.e10, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36334990

ABSTRACT

STATEMENT OF PROBLEM: Studies that compared the fracture strength of monolithic lithium disilicate and 5-mol% yttria partially stabilized zirconia multiunit fixed dental prostheses are sparse. PURPOSE: As the connector is the weakest part of a fixed dental prosthesis, the purpose of this in vitro study was to investigate the effect of connector designs and material on the fracture strength of 3-unit monolithic fixed dental prostheses. MATERIAL AND METHODS: Resin-ceramic canine and premolar teeth (N=144) were prepared for fixed dental prosthesis abutments. Prostheses with 3 connector designs (width=height, widthheight) were made from 2 types of lithium disilicate (IPS e.max CAD and Amber Mill) and 5-mol% yttria partially stabilized zirconia (3M Lava Esthetic and Katana Zirconia UTML). Fracture strengths were measured after 200 000 cycles of dynamic loading of 50 N and thermocycling at 5 °C and 55 °C, and the fracture patterns were analyzed. Two-way analysis of variance and the Fisher exact test were used for statistical analysis (α=.05). RESULTS: The material and connector design affected the fracture strength of fixed dental prostheses (P<.05), and a significant interaction was found between the material and connector design (P<.05). The IPS e.max CAD material had significantly lower fracture strength than Amber Mill, 3M Lava Esthetic, or Katana Zirconia UTML (P<.05). Connector designs with a greater width versus height showed significantly lower fracture strengths than other designs (P<.05). CONCLUSIONS: The connector design of 3-unit fixed dental prostheses, particularly the connector height, may affect fracture strength depending on the prosthesis material.


Subject(s)
Dental Implants , Dental Restoration Failure , Dental Stress Analysis , Amber , Materials Testing , Esthetics, Dental , Dental Porcelain , Zirconium , Computer-Aided Design , Ceramics , Dental Materials
20.
Biochem Biophys Res Commun ; 560: 45-51, 2021 06 30.
Article in English | MEDLINE | ID: mdl-33965788

ABSTRACT

Rapidly proliferating cells such as vascular smooth muscle cells (VSMCs) require metabolic programs to support increased energy and biomass production. Thus, targeting glutamine metabolism by inhibiting glutamine transport could be a promising strategy for vascular disorders such as atherosclerosis, stenosis, and restenosis. V-9302, a competitive antagonist targeting the glutamine transporter, has been investigated in the context of cancer; however, its role in VSMCs is unclear. Here, we examined the effects of blocking glutamine transport in fetal bovine serum (FBS)- or platelet-derived growth factor (PDGF)-stimulated VSMCs using V-9302. We found that V-9302 inhibited mTORC1 activity and mitochondrial respiration, thereby suppressing FBS- or PDGF-stimulated proliferation and migration of VSMCs. Moreover, V-9302 attenuated carotid artery ligation-induced neointima in mice. Collectively, the data suggest that targeting glutamine transport using V-9302 is a promising therapeutic strategy to ameliorate occlusive vascular disease.


Subject(s)
Cell Movement/drug effects , Muscle, Smooth, Vascular/drug effects , Neointima/drug therapy , Amino Acid Transport System A/antagonists & inhibitors , Amino Acid Transport System A/metabolism , Animals , Carotid Arteries/surgery , Cell Cycle/drug effects , Cell Proliferation/drug effects , Cell Respiration/drug effects , Cells, Cultured , Ligation , Male , Mechanistic Target of Rapamycin Complex 1/metabolism , Mice, Inbred C57BL , Mitochondria/drug effects , Mitochondria/metabolism , Muscle, Smooth, Vascular/metabolism , Neointima/etiology , Neointima/pathology , Platelet-Derived Growth Factor/pharmacology , Rats, Sprague-Dawley , Serum Albumin, Bovine/pharmacology
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