116 results on '"Na DH"'
Search Results
2. Turbulent equipartition pinch of toroidal momentum in spherical torus
- Author
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Hahm, TS, Lee, J, Wang, WX, Diamond, PH, Choi, GJ, Na, DH, Na, YS, Chung, KJ, and Hwang, YS
- Subjects
momentum transport ,pinch ,spherical torus ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics ,Fluids & Plasmas - Abstract
We present a new analytic expression for turbulent equipartition (TEP) pinch of toroidal angular momentum originating from magnetic field inhomogeneity of spherical torus (ST) plasmas. Starting from a conservative modern nonlinear gyrokinetic equation (Hahm et al 1988 Phys. Fluids 31 2670), we derive an expression for pinch to momentum diffusivity ratio without using a usual tokamak approximation of B∝1/R which has been previously employed for TEP momentum pinch derivation in tokamaks (Hahm et al 2007 Phys. Plasmas 14 072302). Our new formula is evaluated for model equilibria of National Spherical Torus eXperiment (NSTX) (Ono et al 2001 Nucl. Fusion 41 1435) and Versatile Experiment Spherical Torus (VEST) (Chung et al 2013 Plasma Sci. Technol. 15 244) plasmas. Our result predicts stronger inward pinch for both cases, as compared to the prediction based on the tokamak formula.
- Published
- 2014
3. E × B shear suppression of turbulence in diverted H-mode plasmas: role of edge magnetic shear
- Author
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Hahm, TS, Na, DH, Lee, JW, Park, JW, Na, YS, Kim, SS, Ko, WH, Diamond, PH, Jhang, Hogun, and Jeon, YM
- Subjects
Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics ,Fluids & Plasmas - Abstract
We show that strong edge magnetic shear, which is generic to divertor plasmas, makes the E × B shearing of turbulence eddys in toroidal geometry more effective. From calculations of the E × B shearing rates for KSTAR edge parameters, we conclude that the enhanced magnetic shear at the diverted KSTAR plasma edge facilitates E × B shear suppression of turbulence and ensuing H-mode transition. © 2013 IAEA, Vienna.
- Published
- 2013
4. Application of neural networks to minimize front end bending of material in plate rolling process
- Author
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Park, JS, primary, Na, DH, additional, Yang, Z, additional, Hur, SM, additional, Chung, SH, additional, and Lee, Y, additional
- Published
- 2015
- Full Text
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5. Application of neural networks to minimize front end bending of material in plate rolling process
- Author
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Park, JS, Na, DH, Yang, Z, Hur, SM, Chung, SH, and Lee, Y
- Abstract
This study proposes an approach that combines a trained neural network with a bisection algorithm to minimize the front end bending of material that occurs during plate rolling. With finite element analysis of plate rolling, front end bending data set was generated under conditions where the three rolling parameters (percentage reduction, entry material thicknesses, and percentage difference in peripheral speed between the top and bottom work rolls) varied at regular intervals. The finite element model was validated by comparing the computed roll forces, with the ones measured from a pilot plate rolling test. The pilot hot plate rolling test, wherein the rotational speeds/rates of two work rolls were independently controlled, was also performed, to validate the proposed approach. The proposed approach predicted the percentage difference in peripheral speed that minimized front end bending of the rolled material within 1 s. When the percentage difference in peripheral speed determined for the selected reduction and entry material thicknesses were input, the measured front end bending was only up to about 5 mm, which is negligible value because the ratio of the front end bending to roll diameter in the pilot plate rolling mill is only 0.0071 (5/700 mm), which is much lower than the ratio (0.02) in an actual plate rolling mill.
- Published
- 2016
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6. Advancements in Research on Genetic Kidney Diseases Using Human-Induced Pluripotent Stem Cell-Derived Kidney Organoids.
- Author
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Na DH, Cui S, Fang X, Lee H, Eum SH, Shin YJ, Lim SW, Yang CW, and Chung BH
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- Humans, Animals, CRISPR-Cas Systems genetics, Organoids pathology, Organoids metabolism, Induced Pluripotent Stem Cells metabolism, Kidney Diseases genetics, Kidney Diseases pathology, Kidney pathology
- Abstract
Genetic or hereditary kidney disease stands as a pivotal cause of chronic kidney disease (CKD). The proliferation and widespread utilization of DNA testing in clinical settings have notably eased the diagnosis of genetic kidney diseases, which were once elusive but are now increasingly identified in cases previously deemed CKD of unknown etiology. However, despite these diagnostic strides, research into disease pathogenesis and novel drug development faces significant hurdles, chiefly due to the dearth of appropriate animal models and the challenges posed by limited patient cohorts in clinical studies. Conversely, the advent and utilization of human-induced pluripotent stem cells (hiPSCs) offer a promising avenue for genetic kidney disease research. Particularly, the development of hiPSC-derived kidney organoid systems presents a novel platform for investigating various forms of genetic kidney diseases. Moreover, the integration of the CRISPR/Cas9 technique into this system holds immense potential for efficient research on genetic kidney diseases. This review aims to explore the applications of in vitro kidney organoids generated from hiPSCs in the study of diverse genetic kidney diseases. Additionally, it will delve into the limitations of this research platform and outline future perspectives for advancing research in this crucial area.
- Published
- 2024
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7. Development and Validation of a Multiplex TaqMan Probe qPCR Assay Specific for Three Rust Fungi Infecting Meliosma myriantha .
- Author
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Na DH, Lee DJ, and Choi YJ
- Subjects
- DNA, Ribosomal Spacer genetics, Real-Time Polymerase Chain Reaction methods, Reproducibility of Results, Vitis microbiology, Basidiomycota genetics, Basidiomycota isolation & purification, Basidiomycota classification, Plant Diseases microbiology, DNA, Fungal genetics, Multiplex Polymerase Chain Reaction methods
- Abstract
Rust fungi are the largest group of obligate plant pathogens and cause severe damage to global forests and agricultural security. Meliosma myriantha , a tree species native to East Asia (China, Japan, and Korea), is vulnerable to three rust species: Neophysopella meliosmae , N. meliosmae-myrianthae , and N. vitis . The early symptoms of infection are indistinguishable between these species, making an accurate and rapid diagnosis challenging. The urediniospores of N. meliosmae-myrianthae and N. vitis are also known to infect economically relevant grapevines ( Vitis spp.) and ivies ( Parthenocissus spp.), respectively, rendering early detection and identification even more important. To address this issue, we developed a multiplex quantitative polymerase chain reaction assay equipped with TaqMan probes targeting the internal transcribed spacer rDNA sequences specific to the three rust pathogens. This assay successfully detected minute quantities (5 fg for N. meliosmae-myrianthae and 50 fg for N. meliosmae and N. vitis ) of DNA from the three Neophysopella species and demonstrated consistent reliability when applied to fresh and herbarium samples collected from M. myriantha , grapevines, and ivies. In conclusion, this novel assay is a rapid and robust diagnostic tool for the three rust pathogens, N. meliosmae , N. meliosmae-myrianthae , and N. vitis , and offers the potential to identify and detect their global movement and spread to grapevines, ivies, and trees., Competing Interests: The author(s) declare no conflict of interest.
- Published
- 2024
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8. Neuroprotective effects of cerebroprotein hydrolysate and its combination with antioxidants against oxidative stress-induced HT22 cell death.
- Author
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Yang EJ, Kim JC, and Na DH
- Abstract
This study aimed to investigate the neuroprotective effects of cerebroprotein hydrolysate (CPH) against oxidative stress-induced HT22 cell death. Additionally, the effect of antioxidants such as quercetin (QC) and N -acetyl-L-cysteine (NAC) on the neuroprotective activity of CPH was evaluated. The mouse-derived hippocampal neuronal cell line HT22 was pretreated with CPH or a mixture of CPH and QC or NAC. HT22 cell death was induced by either 10 mM glutamate, 2.5 μM amyloid-β (Aβ)
25-35 , and 300 μM cobalt chloride (CoCl2 ). As results, CPH effectively alleviated HT22 cell death induced by glutamate, Aβ25-35 , and CoCl2 . In addition, CPH combination with QC augmented cell viability in both glutamate- and Aβ25-35 -stressed conditions but had no synergic effect on the CoCl2 -stressed condition. The synergic effect of CPH and NAC combination was observed under all cell death conditions. The neuroprotective actions of CPH and its combinations with QC or NAC against various oxidative stress-induced HT22 cell deaths were demonstrated, providing a promising strategy for developing CPH preparations for the prevention and/or treatment of neurodegenerative diseases such as Alzheimer's disease., Competing Interests: Conflict of interestThe authors have no competing interests to declare., (© The Author(s) under exclusive licence to Korean Society of Toxicology 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)- Published
- 2024
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9. Laparoscopic Salvage Surgery for Infrarenal Para-aortic Lymph Node Recurrence of Rectal Cancer.
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Na DH, Seo AN, and Park SY
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- Humans, Female, Lymph Nodes surgery, Lymph Nodes pathology, Lymph Node Excision, Abdomen, Neoplasm Staging, Retrospective Studies, Laparoscopy, Rectal Neoplasms surgery, Rectal Neoplasms pathology, Uterine Cervical Neoplasms pathology, Uterine Cervical Neoplasms surgery
- Published
- 2024
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10. Single-port versus multiport robotic total mesorectal excision for rectal cancer: initial experiences by case-matched analysis of short-term outcomes.
- Author
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Jeong MH, Kim HJ, Choi GS, Song SH, Park JS, Park SY, Lee SM, and Na DH
- Abstract
Purpose: The da Vinci single-port (SP) system has been used in various surgical fields, including colorectal surgery. However, limited experience has been reported on its safety and feasibility. This study aims to evaluate the short-term outcomes of SP robotic surgery for the treatment of rectal cancer compared with multiport (MP) robotic surgery., Methods: Rectal cancer patients who underwent curative resection in 2020 were reviewed. A total of 43 patients underwent robotic total mesorectal excision (TME), of which 26 (13 in each group, SP
TME vs. MPTME ) were included in the case-matched cohort for analysis. Intraoperative and postoperative outcomes and pathological results were compared between the 2 groups., Results: Median tumor height was similar between the 2 groups (SPTME vs. MPTME : 5.9 cm [range, 2.2-9.6 cm] vs. 6.7 cm [range, 3.4-10.0 cm], P = 0.578). Preoperative chemoradiotherapy was equally performed (38.5%). The median estimated blood loss was less (20.0 mL [range, 5.0-20.0 mL] vs. 30.0 mL [range, 20.0-30.0 mL], P = 0.020) and the median hospital stay was shorter (7 days [range, 6-8 days] vs. 8 days [range, 7-9 days], P = 0.055) in the SPTME group. Postoperative complications did not differ (SPTME vs. MPTME : 7.7% vs. 23.1%, P = 0.587). One patient in the SPTME group and 3 in the MPTME group experienced anastomotic leakage., Conclusion: SP robotic TME showed perioperative outcomes similar to MP robotic TME. The SP robotic system can be considered a surgical option for the treatment of rectal cancer. Further prospective randomized trials with larger cohorts are required., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported., (Copyright © 2023, the Korean Surgical Society.)- Published
- 2023
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11. Single-Port Robotic Intersphincteric Resection for the Treatment of Rectal Cancer.
- Author
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Kim HJ, Choi GS, Song SH, Park JS, Park SY, Lee SM, Na DH, and Jeong MH
- Subjects
- Humans, Retrospective Studies, Pelvis, Robotic Surgical Procedures methods, Robotics methods, Rectal Neoplasms surgery, Rectal Neoplasms pathology
- Abstract
Background: The da Vinci Single-port (SP) system is designed to facilitate single-incision robotic surgery in a narrow space. We developed a new procedure of intersphincteric resection (ISR) using the SP platform and evaluated the technical safety and feasibility of this procedure for the treatment of very low rectal cancer., Materials and Methods: Eleven rectal cancer patients who underwent SP robotic ISR between August 2020 and July 2021 were included. Patients' clinical characteristics, operative and pathologic findings of the patients were retrospectively analyzed., Results: The median tumor height was 3 cm (range, 2-4 cm). A single docking was performed, and the median docking time was 3 min 10 sec (range, 2 min 50 sec-3 min 30 sec). The median total operation time was 210 min (range, 150-280 min), and the median time of pelvic dissection was 57 min (range, 45-68 min). All patients presented with negative distal resection margins [median 1 cm (range, 0.5-2.0 cm)], and only one patient had less than 1mm of circumferential resection margin (0.9 mm)., Conclusions: Our initial experience suggests that SP robotic ISR is safe and feasible., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2023
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12. Pathogenic Role of RAGE in Tau Transmission and Memory Deficits.
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Kim Y, Park H, Kim Y, Kim SH, Lee JH, Yang H, Kim SJ, Li CM, Lee H, Na DH, Moon S, Shin Y, Kam TI, Lee HW, Kim S, Song JJ, and Jung YK
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- Animals, Mice, Brain metabolism, Disease Models, Animal, Memory Disorders metabolism, Mice, Transgenic, Alzheimer Disease metabolism, Receptor for Advanced Glycation End Products metabolism, tau Proteins metabolism, Tauopathies metabolism
- Abstract
Background: In tauopathies, brain regions with tau accumulation strongly correlate with clinical symptoms, and spreading of misfolded tau along neural network leads to disease progression. However, the underlying mechanisms by which tau proteins enter neurons during pathological propagation remain unclear., Methods: To identify membrane receptors responsible for neuronal propagation of tau oligomers, we established a cell-based tau uptake assay and screened complementary DNA expression library. Tau uptake and propagation were analyzed in vitro and in vivo using a microfluidic device and stereotactic injection. The cognitive function of mice was assessed using behavioral tests., Results: From a genome-wide cell-based functional screening, RAGE (receptor for advanced glycation end products) was isolated to stimulate the cellular uptake of tau oligomers. Rage deficiency reduced neuronal uptake of pathological tau prepared from rTg4510 mouse brains or cerebrospinal fluid from patients with Alzheimer's disease and slowed tau propagation between neurons cultured in a 3-chamber microfluidic device. RAGE levels were increased in the brains of rTg4510 mice and tau oligomer-treated neurons. Rage knockout decreased tau transmission in the brains of nontransgenic mice after injection with Alzheimer's disease patient-derived tau and ameliorated memory loss after injection with GFP-P301L-tau-AAV. Treatment of RAGE antagonist FPS-ZM1 blocked transsynaptic tau propagation and inflammatory responses and alleviated cognitive impairment in rTg4510 mice., Conclusions: These results suggest that in neurons and microglia, RAGE binds to pathological tau and facilitates neuronal tau pathology progression and behavioral deficits in tauopathies., (Copyright © 2022 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
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13. Efficacy of air leak test in detection of anastomotic leaks after rectal excision: a retrospective case-controlled study.
- Author
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Song SH, Park JS, Choi GS, Park SY, Kim HJ, Lee SM, Na DH, and Jeong MH
- Abstract
Purpose: Although its efficacy is uncertain, an intraoperative air leak test (ALT) is commonly used to detect mechanical defects following bowel anastomosis. This study aimed to evaluate the efficacy of ALT to detect anastomotic leakage (AL) following rectal excision., Methods: We reviewed our database for patients with rectal cancers who had undergone curative surgery between January 2012 and January 2018. Patients were grouped according to whether or not an ALT was performed. Propensity score analyses were performed to compare outcomes for groups in a 1:1 case-matched cohort., Results: In total, 1,191 patients underwent rectal excision; 438 (219 in each group) formed the case-matched cohort for analysis. The protective stoma rate was 16.0% and 14.6% in the ALT and the no-ALT groups, respectively (P = 0.791). In the ALT group, 2 patients (0.9%) showed a positive result and were treated with rectal tube drainage, resulting in no leakage. There was no significant difference in postoperative AL rate between the groups (ALT group: 4.6% vs. no-ALT group: 4.1%, P > 0.999)., Conclusion: ALT played a minimal role in detecting AL following rectal excision. Further studies are warranted to validate our results and clarify whether AL can be prevented with ALT or alternative methods., Competing Interests: Conflicts of Interest: No potential conflict of interest relevant to this article was reported., (Copyright © 2023, the Korean Surgical Society.)
- Published
- 2023
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14. Gastrointestinal Permeation Enhancers for the Development of Oral Peptide Pharmaceuticals.
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Kim JC, Park EJ, and Na DH
- Abstract
Recently, two oral-administered peptide pharmaceuticals, semaglutide and octreotide, have been developed and are considered as a breakthrough in peptide and protein drug delivery system development. In 2019, the Food and Drug Administration (FDA) approved an oral dosage form of semaglutide developed by Novo Nordisk (Rybelsus
® ) for the treatment of type 2 diabetes. Subsequently, the octreotide capsule (Mycapssa® ), developed through Chiasma's Transient Permeation Enhancer (TPE) technology, also received FDA approval in 2020 for the treatment of acromegaly. These two oral peptide products have been a significant success; however, a major obstacle to their oral delivery remains the poor permeability of peptides through the intestinal epithelium. Therefore, gastrointestinal permeation enhancers are of great relevance for the development of subsequent oral peptide products. Sodium salcaprozate (SNAC) and sodium caprylate (C8) have been used as gastrointestinal permeation enhancers for semaglutide and octreotide, respectively. Herein, we briefly review two approved products, Rybelsus® and Mycapssa® , and discuss the permeation properties of SNAC and medium chain fatty acids, sodium caprate (C10) and C8, focusing on Eligen technology using SNAC, TPE technology using C8, and gastrointestinal permeation enhancement technology (GIPET) using C10.- Published
- 2022
- Full Text
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15. Cleavage-Responsive Biofactory T Cells Suppress Infectious Diseases-Associated Hypercytokinemia.
- Author
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Kim H, Son B, Seo EU, Kwon M, Ahn JH, Shin H, Song GY, Park EJ, Na DH, Cho SW, Kim HN, Park HH, and Lee W
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- Antigens, CD metabolism, Antigens, CD pharmacology, Cytokine Release Syndrome, Endothelial Cells metabolism, Humans, Peptides metabolism, Receptor, PAR-1 metabolism, Receptors, Cell Surface metabolism, T-Lymphocytes metabolism, COVID-19, Communicable Diseases
- Abstract
Severe infectious diseases, such as coronavirus disease 2019 (COVID-19), can induce hypercytokinemia and multiple organ failure. In spite of the growing demand for peptide therapeutics against infectious diseases, current small molecule-based strategies still require frequent administration due to limited half-life and enzymatic digestion in blood. To overcome this challenge, a strategy to continuously express multi-level therapeutic peptide drugs on the surface of immune cells, is established. Here, chimeric T cells stably expressing therapeutic peptides are presented for treatment of severe infectious diseases. Using lentiviral system, T cells are engineered to express multi-level therapeutic peptides with matrix metallopeptidases- (MMP-) and tumor necrosis factor alpha converting enzyme- (TACE-) responsive cleavage sites on the surface. The enzymatic cleavage releases γ-carboxyglutamic acid of protein C (PC-Gla) domain and thrombin receptor agonist peptide (TRAP), which activate endothelial protein C receptor (EPCR) and protease-activated receptor-1 (PAR-1), respectively. These chimeric T cells prevent vascular damage in tissue-engineered blood vessel and suppress hypercytokinemia and lung tissue damages in vivo, demonstrating promise for use of engineered T cells against sepsis and other infectious-related diseases., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)
- Published
- 2022
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16. Emergence of a New Rust Disease of Virginia Creeper ( Parthenocissus quinquefolia ) through a Host Range Expansion of Neophysopella vitis .
- Author
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Na DH, Lee JS, Shin HD, Ono Y, and Choi YJ
- Abstract
Virginia creeper (or five-leaved ivy; Parthenocissus quinquefolia ) is one of the most popular and widely grown climbers worldwide. In September 2021, Virginia creeper leaves with typical rust symptom were found in an arboretum in Korea, with severe damage. Globally, there is no record of a rust disease on Virginia creeper. Using morphological investigation and molecular phylogenetic inferences, the rust agent was identified as Neophysopella vitis , which is a rust pathogen of other Parthenocissus spp. including Boston ivy ( P. tricuspidata ). Given that the two ivy plants, Virginia creeper and Boston ivy, have common habitats, especially on buildings and walls, throughout Korea, and that N. vitis is a ubiquitous rust species affecting Boston ivy in Korea, it is speculated that the host range of N. vitis may recently have expanded from Boston ivy to Virginia creeper. The present study reports a globally new rust disease on Virginia creeper, which could be a major threat to the ornamental creeper., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of the Korean Society of Mycology.)
- Published
- 2022
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17. AK2 is an AMP-sensing negative regulator of BRAF in tumorigenesis.
- Author
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Kim H, Jeong M, Na DH, Ryu SH, Jeong EI, Jung K, Kang J, Lee HJ, Sim T, Yu DY, Yu HC, Cho BH, and Jung YK
- Subjects
- Animals, Carcinogenesis genetics, Cell Line, Tumor, Humans, Mice, Mutation, Adenosine Monophosphate metabolism, Adenylate Kinase metabolism, Carcinoma, Hepatocellular enzymology, Carcinoma, Hepatocellular genetics, Carcinoma, Hepatocellular pathology, Liver Neoplasms enzymology, Liver Neoplasms genetics, Liver Neoplasms pathology, Proto-Oncogene Proteins B-raf genetics, Proto-Oncogene Proteins B-raf metabolism
- Abstract
The RAS-BRAF signaling is a major pathway of cell proliferation and their mutations are frequently found in human cancers. Adenylate kinase 2 (AK2), which modulates balance of adenine nucleotide pool, has been implicated in cell death and cell proliferation independently of its enzyme activity. Recently, the role of AK2 in tumorigenesis was in part elucidated in some cancer types including lung adenocarcinoma and breast cancer, but the underlying mechanism is not clear. Here, we show that AK2 is a BRAF-suppressor. In in vitro assays and cell model, AK2 interacted with BRAF and inhibited BRAF activity and downstream ERK phosphorylation. Energy-deprived conditions in cell model and the addition of AMP to cell lysates strengthened the AK2-BRAF interaction, suggesting that AK2 is involved in the regulation of BRAF activity in response to cell metabolic state. AMP facilitated the AK2-BRAF complex formation through binding to AK2. In a panel of HCC cell lines, AK2 expression was inversely correlated with ERK/MAPK activation, and AK2-knockdown or -knockout increased BRAF activity and promoted cell proliferation. Tumors from HCC patients showed low-AK2 protein expression and increased ERK activation compared to non-tumor tissues and the downregulation of AK2 was also verified by two microarray datasets (TCGA-LIHC and GSE14520). Moreover, AK2/BRAF interaction was abrogated by RAS activation in in vitro assay and cell model and in a mouse model of HRAS
G12V -driven HCC, and AK2 ablation promoted tumor growth and BRAF activity. AK2 also bound to BRAF inhibitor-insensitive BRAF mutants and attenuated their activities. These findings indicate that AK2 monitoring cellular AMP levels is indeed a negative regulator of BRAF, linking the metabolic status to tumor growth., (© 2022. The Author(s).)- Published
- 2022
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18. Nano Differential Scanning Fluorimetry-Based Thermal Stability Screening and Optimal Buffer Selection for Immunoglobulin G.
- Author
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Kim SH, Yoo HJ, Park EJ, and Na DH
- Abstract
Nano differential scanning fluorimetry (nanoDSF) is a high-throughput protein stability screening technique that simultaneously monitors protein unfolding and aggregation properties. The thermal stability of immunoglobulin G (IgG) was investigated in three different buffers (sodium acetate, sodium citrate, and sodium phosphate) ranging from pH 4 to 8. In all three buffers, the midpoint temperature of thermal unfolding ( T
m ) showed a tendency to increase as the pH increased, but the aggregation propensity was different depending on the buffer species. The best stability against aggregation was obtained in the sodium acetate buffers below pH 4.6. On the other hand, IgG in the sodium citrate buffer had higher aggregation and viscosity than in the sodium acetate buffer at the same pH. Difference of aggregation between acetate and citrate buffers at the same pH could be explained by a protein-protein interaction study, performed with dynamic light scattering, which suggested that intermolecular interaction is attractive in citrate buffer but repulsive in acetate buffer. In conclusion, this study indicates that the sodium acetate buffer at pH 4.6 is suitable for IgG formulation, and the nanoDSF method is a powerful tool for thermal stability screening and optimal buffer selection in antibody formulations.- Published
- 2021
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19. Bioinspired DNase-I-Coated Melanin-Like Nanospheres for Modulation of Infection-Associated NETosis Dysregulation.
- Author
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Park HH, Park W, Lee YY, Kim H, Seo HS, Choi DW, Kwon HK, Na DH, Kim TH, Choy YB, Ahn JH, Lee W, and Park CG
- Published
- 2021
- Full Text
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20. Recent Progress in Drug Release Testing Methods of Biopolymeric Particulate System.
- Author
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Kim Y, Park EJ, Kim TW, and Na DH
- Abstract
Biopolymeric microparticles have been widely used for long-term release formulations of short half-life chemicals or synthetic peptides. Characterization of the drug release from microparticles is important to ensure product quality and desired pharmacological effect. However, there is no official method for long-term release parenteral dosage forms. Much work has been done to develop methods for in vitro drug release testing, generally grouped into three major categories: sample and separate, dialysis membrane, and continuous flow (flow-through cell) methods. In vitro drug release testing also plays an important role in providing insight into the in vivo performance of a product. In vitro release test with in vivo relevance can reduce the cost of conducting in vivo studies and accelerate drug product development. Therefore, investigation of the in vitro-in vivo correlation (IVIVC) is increasingly becoming an essential part of particulate formulation development. This review summarizes the principles of the in vitro release testing methods of biopolymeric particulate system with the recent research articles and discusses their characteristics including IVIVC, accelerated release testing methods, and stability of encapsulated drugs.
- Published
- 2021
- Full Text
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21. Lung-selective 25-hydroxycholesterol nanotherapeutics as a suppressor of COVID-19-associated cytokine storm.
- Author
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Kim H, Lee HS, Ahn JH, Hong KS, Jang JG, An J, Mun YH, Yoo SY, Choi YJ, Yun MY, Song GY, Joo J, Na DH, Kim HN, Park HH, Lee JY, and Lee W
- Abstract
In response to the coronavirus disease-19 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), global efforts are focused on the development of new therapeutic interventions. For the treatment of COVID-19, selective lung-localizing strategies hold tremendous potential, as SARS-CoV-2 invades the lung via ACE2 receptors and causes severe pneumonia. Similarly, recent reports have shown the association of COVID-19 with decreased 25-hydroxycholesterol (25-HC) and increased cytokine levels. This mechanism, which involves the activation of inflammatory NF-κB- and SREBP2-mediated inflammasome signaling pathways, is believed to play a crucial role in COVID-19 pathogenesis, inducing acute respiratory distress syndrome (ARDS) and sepsis. To resolve those clinical conditions observed in severe SARS-CoV-2 patients, we report 25-HC and didodecyldimethylammonium bromide (DDAB) nanovesicles (25-HC@DDAB) as a COVID-19 drug candidate for the restoration of intracellular cholesterol level and suppression of cytokine storm. Our data demonstrate that 25-HC@DDAB can selectively accumulate the lung tissues and effectively downregulate NF-κB and SREBP2 signaling pathways in COVID-19 patient-derived PBMCs, reducing inflammatory cytokine levels. Altogether, our findings suggest that 25-HC@DDAB is a promising candidate for the treatment of symptoms associated with severe COVID-19 patients, such as decreased cholesterol level and cytokine storm., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Author(s).)
- Published
- 2021
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22. PEGylated nanoparticle albumin-bound steroidal ginsenoside derivatives ameliorate SARS-CoV-2-mediated hyper-inflammatory responses.
- Author
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Park HH, Kim H, Lee HS, Seo EU, Kim JE, Lee JH, Mun YH, Yoo SY, An J, Yun MY, Kang NW, Kim DD, Na DH, Hong KS, Jang JG, Ahn JH, Bae JS, Song GY, Lee JY, Kim HN, and Lee W
- Subjects
- Albumins, Animals, Humans, Polyethylene Glycols, SARS-CoV-2, COVID-19, Ginsenosides pharmacology, Nanoparticles
- Abstract
The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on a global scale urges prompt and effective countermeasures. Recently, a study has reported that coronavirus disease-19 (COVID-19), the disease caused by SARS-CoV-2 infection, is associated with a decrease in albumin level, an increase in NETosis, blood coagulation, and cytokine level. Here, we present drug-loaded albumin nanoparticles as a therapeutic agent to resolve the clinical outcomes observed in severe SARS-CoV-2 patients. PEGylated nanoparticle albumin-bound (PNAB) was used to promote prolonged bioactivity of steroidal ginsenoside saponins, PNAB-Rg6 and PNAB-Rgx365. Our data indicate that the application of PNAB-steroidal ginsenoside can effectively reduce histone H4 and NETosis-related factors in the plasma, and alleviate SREBP2-mediated systemic inflammation in the PBMCs of SARS-CoV-2 ICU patients. The engineered blood vessel model confirmed that these drugs are effective in suppressing blood clot formation and vascular inflammation. Moreover, the animal model experiment showed that these drugs are effective in promoting the survival rate by alleviating tissue damage and cytokine storm. Altogether, our findings suggest that these PNAB-steroidal ginsenoside drugs have potential applications in the treatment of symptoms associated with severe SARS-CoV-2 patients, such as coagulation and cytokine storm., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2021
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23. Blocking microglial activation of reactive astrocytes is neuroprotective in models of Alzheimer's disease.
- Author
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Park JS, Kam TI, Lee S, Park H, Oh Y, Kwon SH, Song JJ, Kim D, Kim H, Jhaldiyal A, Na DH, Lee KC, Park EJ, Pomper MG, Pletnikova O, Troncoso JC, Ko HS, Dawson VL, Dawson TM, and Lee S
- Subjects
- Alzheimer Disease genetics, Alzheimer Disease prevention & control, Amyloid beta-Peptides toxicity, Animals, Astrocytes drug effects, Cells, Cultured, Exenatide administration & dosage, Glucagon-Like Peptide-1 Receptor agonists, Humans, Male, Maze Learning drug effects, Maze Learning physiology, Mice, Mice, Transgenic, Microglia drug effects, Neuroprotection drug effects, Neuroprotective Agents administration & dosage, Peptide Fragments toxicity, Alzheimer Disease metabolism, Astrocytes metabolism, Glucagon-Like Peptide-1 Receptor metabolism, Microglia metabolism, Neuroprotection physiology
- Abstract
Alzheimer's disease (AD) is the most common cause of age-related dementia. Increasing evidence suggests that neuroinflammation mediated by microglia and astrocytes contributes to disease progression and severity in AD and other neurodegenerative disorders. During AD progression, resident microglia undergo proinflammatory activation, resulting in an increased capacity to convert resting astrocytes to reactive astrocytes. Therefore, microglia are a major therapeutic target for AD and blocking microglia-astrocyte activation could limit neurodegeneration in AD. Here we report that NLY01, an engineered exedin-4, glucagon-like peptide-1 receptor (GLP-1R) agonist, selectively blocks β-amyloid (Aβ)-induced activation of microglia through GLP-1R activation and inhibits the formation of reactive astrocytes as well as preserves neurons in AD models. In two transgenic AD mouse models (5xFAD and 3xTg-AD), repeated subcutaneous administration of NLY01 blocked microglia-mediated reactive astrocyte conversion and preserved neuronal viability, resulting in improved spatial learning and memory. Our study indicates that the GLP-1 pathway plays a critical role in microglia-reactive astrocyte associated neuroinflammation in AD and the effects of NLY01 are primarily mediated through a direct action on Aβ-induced GLP-1R
+ microglia, contributing to the inhibition of astrocyte reactivity. These results show that targeting upregulated GLP-1R in microglia is a viable therapy for AD and other neurodegenerative disorders.- Published
- 2021
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24. Usefulness of BK virus-specific interferon-γ enzyme-linked immunospot assay for predicting the outcome of BK virus infection in kidney transplant recipients.
- Author
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Bae H, Na DH, Chang JY, Park KH, Min JW, Ko EJ, Lee H, Yang CW, Chung BH, and Oh EJ
- Subjects
- Enzyme-Linked Immunospot Assay, Humans, Interferon-gamma, BK Virus, Kidney Transplantation adverse effects, Polyomavirus Infections diagnosis, Tumor Virus Infections diagnosis
- Abstract
Background/aims: To investigate if BK virus (BKV)-specific T cell immunity measured by an interferon-γ enzyme-linked immunospot (ELISPOT) assay can predict the outcome of BK virus infection in kidney transplant recipients (KTRs)., Methods: We included 68 KTRs with different viremia status (no viremia [n = 17], BK viremia [n = 27], and cleared viremia [n = 24]) and 44 healthy controls (HCs). The BK viremia group was divided into controller (< 3 months) and noncontroller (> 3 months) according to sustained duration of BKV infection. We compared BKV-ELISPOT results against five BKV peptides (large tumor antigen [LT], St, VP1-3)., Results: BKV-ELISPOT results were higher in three KTRs groups with different BKV infection status than the HCs group (p < 0.05). In KTR groups, they were higher in cleared viremia group than no viremia or BK viremia group. Within the BK viremia group, controller group had higher LT-ELISPOT results compared to noncontroller group (p = 0.032). Also, KTRs without BK virus-associated nephropathy (BKVN) had higher LT, St, VP1, and VP2-ELISPOT results than those with BKVN (p < 0.05)., Conclusion: BKV-ELISPOT assay may be effective in predicting clinical outcomes of BKV infection in terms of clearance of BK virus and development of BKVN.
- Published
- 2021
- Full Text
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25. Long-acting nanoparticulate DNase-1 for effective suppression of SARS-CoV-2-mediated neutrophil activities and cytokine storm.
- Author
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Lee YY, Park HH, Park W, Kim H, Jang JG, Hong KS, Lee JY, Seo HS, Na DH, Kim TH, Choy YB, Ahn JH, Lee W, and Park CG
- Subjects
- Animals, COVID-19 blood, COVID-19 immunology, Cytokine Release Syndrome etiology, Deoxyribonuclease I administration & dosage, Dexamethasone therapeutic use, Disease Models, Animal, Drug Evaluation, Preclinical, Extracellular Traps drug effects, Humans, Indoles, Male, Mice, Mice, Inbred C57BL, Multiple Organ Failure blood, Multiple Organ Failure etiology, Multiple Organ Failure prevention & control, NF-kappa B blood, Neutrophils enzymology, Peroxidase blood, Polyethylene Glycols, Polyglactin 910, Polymers, Sepsis etiology, Sepsis immunology, COVID-19 complications, Cytokine Release Syndrome drug therapy, DNA blood, Deoxyribonuclease I therapeutic use, Drug Carriers administration & dosage, Nanoparticles administration & dosage, Neutrophils drug effects, SARS-CoV-2, Sepsis drug therapy
- Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new strain of coronavirus not previously identified in humans. Globally, the number of confirmed cases and mortality rates of coronavirus disease 2019 (COVID-19) have risen dramatically. Currently, there are no FDA-approved antiviral drugs and there is an urgency to develop treatment strategies that can effectively suppress SARS-CoV-2-mediated cytokine storms, acute respiratory distress syndrome (ARDS), and sepsis. As symptoms progress in patients with SARS-CoV-2 sepsis, elevated amounts of cell-free DNA (cfDNA) are produced, which in turn induce multiple organ failure in these patients. Furthermore, plasma levels of DNase-1 are markedly reduced in SARS-CoV-2 sepsis patients. In this study, we generated recombinant DNase-1-coated polydopamine-poly(ethylene glycol) nanoparticulates (named long-acting DNase-1), and hypothesized that exogenous administration of long-acting DNase-1 may suppress SARS-CoV-2-mediated neutrophil activities and the cytokine storm. Our findings suggest that exogenously administered long-acting nanoparticulate DNase-1 can effectively reduce cfDNA levels and neutrophil activities and may be used as a potential therapeutic intervention for life-threatening SARS-CoV-2-mediated illnesses., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Published
- 2021
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26. Bioinspired DNase-I-Coated Melanin-Like Nanospheres for Modulation of Infection-Associated NETosis Dysregulation.
- Author
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Park HH, Park W, Lee YY, Kim H, Seo HS, Choi DW, Kwon HK, Na DH, Kim TH, Choy YB, Ahn JH, Lee W, and Park CG
- Abstract
The current outbreak of the beta-coronavirus (beta-Cov) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began in December 2019. No specific antiviral treatments or vaccines are currently available. A recent study has reported that coronavirus disease 2019 (COVID-19), the disease caused by SARS-CoV-2 infection, is associated with neutrophil-specific plasma membrane rupture, and release excessive neutrophil extracellular traps (NETs) and extracellular DNAs (eDNAs). This mechanism involves the activation of NETosis, a neutrophil-specific programmed cell death, which is believed to play a crucial role in COVID-19 pathogenesis. Further progression of the disease can cause uncontrolled inflammation, leading to the initiation of cytokine storms, acute respiratory distress syndrome (ARDS), and sepsis. Herein, it is reported that DNase-I-coated melanin-like nanospheres (DNase-I pMNSs) mitigate sepsis-associated NETosis dysregulation, thereby preventing further progression of the disease. Recombinant DNase-I and poly(ethylene glycol) (PEG) are used as coatings to promote the lengthy circulation and dissolution of NET structure. The data indicate that the application of bioinspired DNase-I pMNSs reduce neutrophil counts and NETosis-related factors in the plasma of SARS-CoV-2 sepsis patients, alleviates systemic inflammation, and attenuates mortality in a septic mouse model. Altogether, the findings suggest that these nanoparticles have potential applications in the treatment of SARS-CoV-2-related illnesses and other beta-CoV-related diseases., Competing Interests: The authors declare no conflict of interest., (© 2020 The Authors. Published by Wiley‐VCH GmbH.)
- Published
- 2020
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27. Dual peptide-dendrimer conjugate inhibits acetylation of transforming growth factor β-induced protein and improves survival in sepsis.
- Author
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Lee W, Park EJ, Kwon OK, Kim H, Yoo Y, Kim SW, Seo YK, Kim IS, Na DH, and Bae JS
- Subjects
- Acetylation, Animals, Extracellular Matrix Proteins metabolism, Human Umbilical Vein Endothelial Cells metabolism, Mice, Mice, Inbred C57BL, Transforming Growth Factor beta metabolism, Dendrimers therapeutic use, Sepsis drug therapy
- Abstract
Sepsis is a potentially fatal complication of infections and there are currently no effective therapeutic options for severe sepsis. In this study, we revealed the secretion mechanism of transforming growth factor β-induced protein (TGFBIp) that was recently identified as a therapeutic target for sepsis, and designed TGFBIp acetylation inhibitory peptide (TAIP) that suppresses acetylation of lysine 676 in TGFBIp. To improve bioavailability and biodegradation of the peptide, TAIP was conjugated to polyamidoamine (PAMAM) dendrimers. Additionally, the cell-penetrating peptide (CPP) was conjugated to the TAIP-modified PAMAM dendrimers for the intracellular delivery of TGFBIp. The resulting nanostructures, decorated with TAIP and CPP via poly(ethylene glycol) linkage, improved the mortality and organ damage in the septic mouse model and suppressed lipopolysaccharide-activated severe vascular inflammatory responses in endothelial cells. Thus, the dendrimer-based nanostructures for delivery of TAIP using CPP show great promise in practical applications in sepsis therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Published
- 2020
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28. Generation of a human induced pluripotent stem cell line (CMCi001-A) from a patient with karyomegalic interstitial nephritis with homozygous frameshift deletion mutation c.1985_1994del10 of the FANCD2/FANCI-Associated Nuclease 1 gene.
- Author
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Na DH, Lim SW, Kim BM, Kim KW, Shin YJ, Chae H, Ko EJ, Yang CW, Kim M, and Chung BH
- Subjects
- Adult, Fanconi Anemia Complementation Group D2 Protein, Fanconi Anemia Complementation Group Proteins, Female, Humans, Leukocytes, Mononuclear, Sequence Deletion, Induced Pluripotent Stem Cells, Nephritis, Interstitial genetics
- Abstract
The human-induced pluripotent stem cell (KIN-hiPSCs) line (CMCi001-A), derived from peripheral blood mononuclear cells (PBMCs) of a 42-year-old woman with karyomegalic interstitial nephritis (KIN) caused by the mutation of FANCD2/FANCI-Associated Nuclease 1 (FAN1) gene, was generated using Sendai virus. KIN-hiPSCs showed a typical human embryonic stem cell like morphology and expressed all pluripotency-associated markers, and directly differentiated into all three germ layers. Karyotyping of PBMCs of the patient and KIN-hiPSCs showed 47, XXX. In summary, we generated a novel patient-specific hiPSC line containing the mutation of FAN1 gene and it can be used to provide additional insights for KIN pathophysiology., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2020
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- View/download PDF
29. Emerging PEGylated non-biologic drugs.
- Author
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Park EJ, Choi J, Lee KC, and Na DH
- Subjects
- Aptamers, Nucleotide administration & dosage, Morphinans administration & dosage, Peptides administration & dosage, Polyethylene Glycols administration & dosage, Drug Carriers chemistry, Drug Development, Polyethylene Glycols chemistry, Technology, Pharmaceutical methods
- Abstract
Introduction : PEGylation is a well-established technology for improving the therapeutic value of drugs by attaching polyethylene glycol (PEG). The first PEGylated enzyme products appeared on the market in the early 1990s; currently, more than 18 PEGylated products have been approved by Food and Drug Administration, which encompass various classes of drug molecules, such as enzymes, interferons, granulocyte colony-stimulating factors, hormones, antibody fragments, coagulation factors, oligonucleotide aptamers, synthetic peptides, and small organic molecules. Areas covered : While PEGylated products mainly comprise biologic drugs, such as recombinant proteins and enzymes, non-biologic drugs have recently emerged as a target for PEGylation. This review focuses on the recent development of PEGylated non-biologic drugs, such as small organic molecules, synthetic peptides, and aptamers. Expert opinion : Several PEGylated versions of anti-cancer drugs, opioid agonists, glucagon-like peptide-1 receptor agonists, and oligonucleotide aptamers are in active development stage, and it is likely that they will have a dramatic impact on the market. Although some safety concerns about PEG in clinical trials have been recently issued, PEGylation is still a commercially attractive proposition as a half-life extension technology for long-acting drug development.
- Published
- 2019
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30. Simultaneous Determination of Cysteamine and Cystamine in Cosmetics by Ion-Pairing Reversed-Phase High-Performance Liquid Chromatography.
- Author
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Kim Y and Na DH
- Abstract
Cysteamine has been used in cosmetics as an antioxidant, a hair straightening agent, and a hair waving agent. However, recent studies indicate that cysteamine can act as an allergen to hairdressers. The objective of this study was to develop and validate a simple and effective reversed-phase high-performance liquid chromatography (RP-HPLC) method for the measurement of cysteamine and its dimer, cystamine. Sodium 1-heptanesulfonate (NaHpSO) was used as an ion-pairing agent to improve chromatographic performance. Separation was performed on a Gemini C18 column (250 mm × 4.6 mm, 5 μm particle size) using a mobile phase composed of 85:15 (v/v) 4 mM NaHpSO in 0.1% phosphoric acid:acetonitrile. UV absorbance was monitored at 215 nm. The RP-HPLC method developed in this study was validated for specificity, linearity, limit of detection, limit of quantitation, precision, accuracy, and recovery. Cysteamine and cystamine were chromatographically resolved from other reducing agents such as thioglycolic acid and cysteine. Extraction using water and chloroform resulted in the recovery for cysteamine and cystamine ranging from 100.2-102.7% and 90.6-98.7%, respectively. This validated RP-HPLC method would be useful for quality control and monitoring of cysteamine and cystamine in cosmetics., Competing Interests: CONFLICT OF INTEREST The authors declare that they have no conflicts of interest.
- Published
- 2019
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31. Targeting of dermal myofibroblasts through death receptor 5 arrests fibrosis in mouse models of scleroderma.
- Author
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Park JS, Oh Y, Park YJ, Park O, Yang H, Slania S, Hummers LK, Shah AA, An HT, Jang J, Horton MR, Shin J, Dietz HC, Song E, Na DH, Park EJ, Kim K, Lee KC, Roschke VV, Hanes J, Pomper MG, and Lee S
- Subjects
- Actins metabolism, Adult, Aged, Animals, Apoptosis drug effects, Apoptosis genetics, Cell Differentiation, Collagen genetics, Collagen metabolism, Dermis metabolism, Dermis pathology, Disease Models, Animal, Female, Fibroblasts drug effects, Fibroblasts metabolism, Fibroblasts pathology, Fibrosis, Gene Expression Regulation, Humans, Male, Mice, Middle Aged, Molecular Targeted Therapy, Myofibroblasts metabolism, Myofibroblasts pathology, Protein Engineering, Receptors, TNF-Related Apoptosis-Inducing Ligand agonists, Receptors, TNF-Related Apoptosis-Inducing Ligand metabolism, Scleroderma, Systemic genetics, Scleroderma, Systemic immunology, Scleroderma, Systemic pathology, Signal Transduction, Actins genetics, Dermis drug effects, Myofibroblasts drug effects, Receptors, TNF-Related Apoptosis-Inducing Ligand genetics, Scleroderma, Systemic drug therapy, TNF-Related Apoptosis-Inducing Ligand pharmacology
- Abstract
Scleroderma is an autoimmune rheumatic disorder accompanied by severe fibrosis in skin and other internal organs. During scleroderma progression, resident fibroblasts undergo activation and convert to α-smooth muscle actin (α-SMA) expressing myofibroblasts (MFBs) with increased capacity to synthesize collagens and fibrogenic components. Accordingly, MFBs are a major therapeutic target for fibrosis in scleroderma and treatment with blocking MFBs could produce anti-fibrotic effects. TLY012 is an engineered human TNF-related apoptosis-inducing ligand (TRAIL) which induces selective apoptosis in transformed cells expressing its cognate death receptors (DRs). Here we report that TLY012 selectively blocks activation of dermal fibroblasts and induces DR-mediated apoptosis in α-SMA
+ MFBs through upregulated DR5 during its activation. In vivo, TLY012 reverses established skin fibrosis to near-normal skin architecture in mouse models of scleroderma. Thus, the TRAIL pathway plays a critical role in tissue remodeling and targeting upregulated DR5 in α-SMA+ MFBs is a viable therapy for fibrosis in scleroderma.- Published
- 2019
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32. Chemical chaperone-conjugated exendin-4 as a cytoprotective agent for pancreatic β-cells.
- Author
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Son S, Park EJ, Kim Y, Lee KC, and Na DH
- Subjects
- Animals, Cell Line, Cell Survival drug effects, Cytoprotection, Diabetes Mellitus, Type 2 drug therapy, Diabetes Mellitus, Type 2 metabolism, Endoplasmic Reticulum Chaperone BiP, Endoplasmic Reticulum Stress drug effects, Eukaryotic Initiation Factor-2 metabolism, Exenatide chemistry, Exenatide pharmacology, Glucagon-Like Peptide-1 Receptor agonists, Heat-Shock Proteins metabolism, Hypoglycemic Agents chemistry, Hypoglycemic Agents pharmacology, Insulin biosynthesis, Insulin-Secreting Cells cytology, Insulin-Secreting Cells metabolism, Male, Mice, Mice, Inbred C57BL, Protective Agents chemistry, Rats, Taurochenodeoxycholic Acid chemistry, Taurochenodeoxycholic Acid pharmacology, Exenatide analogs & derivatives, Insulin-Secreting Cells drug effects, Protective Agents pharmacology
- Abstract
Endoplasmic reticulum stress has been considered a major cause of pancreatic β-cell dysfunction and apoptosis leading to diabetes. Glucagon-like peptide-1 receptor activation and chemical chaperones have been known to reduce endoplasmic reticulum stress and improve β-cell function and survival. The purpose of this study was to prepare and evaluate the chemical chaperone tauroursodeoxycholic acid-conjugated exendin-4 as a protective agent for pancreatic β-cells. Mono-tauroursodeoxycholic acid-Lys
27 -exendin-4 conjugate (TUM1-Ex4) showed better receptor binding affinity than other conjugates with strong in vitro insulinotropic activity in rat pancreatic β-cells and in vivo hypoglycemic activity in type 2 diabetic db/db mice. In INS-1 cells under endoplasmic reticulum stress induced by thapsigargin, TUM1-Ex4 promoted cell survival in a dose-dependent manner. In western blot analysis, TUM1-Ex4 reduced the expression of the endoplasmic reticulum stress marker GRP78 and phosphorylation of the translation initiation factor eIF2α. These results reveal that TUM1-Ex4 accelerates translational recovery and contributes to β-cell protection and survival. The present study indicates that the chemical chaperone-coupled glucagon-like peptide-1 receptor agonist is a feasible therapeutic strategy to enhance β-cell function and survival., (Copyright © 2018 Elsevier Ltd. All rights reserved.)- Published
- 2018
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33. Drying Technologies for the Stability and Bioavailability of Biopharmaceuticals.
- Author
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Emami F, Vatanara A, Park EJ, and Na DH
- Abstract
Solid dosage forms of biopharmaceuticals such as therapeutic proteins could provide enhanced bioavailability, improved storage stability, as well as expanded alternatives to parenteral administration. Although numerous drying methods have been used for preparing dried protein powders, choosing a suitable drying technique remains a challenge. In this review, the most frequent drying methods, such as freeze drying, spray drying, spray freeze drying, and supercritical fluid drying, for improving the stability and bioavailability of therapeutic proteins, are discussed. These technologies can prepare protein formulations for different applications as they produce particles with different sizes and morphologies. Proper drying methods are chosen, and the critical process parameters are optimized based on the proposed route of drug administration and the required pharmacokinetics. In an optimized drying procedure, the screening of formulations according to their protein properties is performed to prepare a stable protein formulation for various delivery systems, including pulmonary, nasal, and sustained-release applications.
- Published
- 2018
- Full Text
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34. Effect of amino acids on the stability of spray freeze-dried immunoglobulin G in sugar-based matrices.
- Author
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Emami F, Vatanara A, Najafabadi AR, Kim Y, Park EJ, Sardari S, and Na DH
- Subjects
- Chemistry, Pharmaceutical, Drug Stability, Freeze Drying, Amino Acids chemistry, Excipients chemistry, Immunoglobulin G chemistry, Trehalose chemistry
- Abstract
The purpose of this study was to prepare spray freeze-dried particles of immunoglobulin G (IgG) using various combinations of trehalose and different amino acids (leucine, phenylalanine, arginine, cysteine, and glycine), and investigate the effect of the amino acids on the stability of IgG during the spray freeze-drying (SFD) process and storage. The morphology and structural integrity of the processed particles were evaluated by physical and spectroscopic techniques. SFD-processed IgG without any excipient resulted in the formation of aggregates corresponding to approximately 14% of IgG. In contrast, IgG formulations stabilized using an optimal level of leucine, phenylalanine, or glycine in the presence of trehalose displayed aggregates <2.2%. In particular, phenylalanine combined with trehalose was most effective in stabilizing IgG against shear, freezing, and dehydration stresses during SFD. Arginine and cysteine were destabilizers displaying aggregation and fragmentation of IgG, respectively. Aggregation and fragmentation were evaluated by dynamic light scattering, ultraviolet spectrophotometry, size-exclusion chromatography, and microchip capillary gel electrophoresis. The IgG formulations prepared with leucine, phenylalanine, or glycine in the presence of trehalose showed good stability after storage at 40 °C and 75% relative humidity for 2 months. Thus, a combination of the excipients trehalose and uncharged, nonpolar amino acids appears effective for production of stable SFD IgG formulations., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2018
- Full Text
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35. Block of A1 astrocyte conversion by microglia is neuroprotective in models of Parkinson's disease.
- Author
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Yun SP, Kam TI, Panicker N, Kim S, Oh Y, Park JS, Kwon SH, Park YJ, Karuppagounder SS, Park H, Kim S, Oh N, Kim NA, Lee S, Brahmachari S, Mao X, Lee JH, Kumar M, An D, Kang SU, Lee Y, Lee KC, Na DH, Kim D, Lee SH, Roschke VV, Liddelow SA, Mari Z, Barres BA, Dawson VL, Lee S, Dawson TM, and Ko HS
- Subjects
- Amyloid metabolism, Animals, Disease Models, Animal, Humans, Mice, Inbred C57BL, Mice, Transgenic, alpha-Synuclein metabolism, Astrocytes pathology, Microglia pathology, Neuroprotective Agents metabolism, Parkinson Disease pathology
- Abstract
Activation of microglia by classical inflammatory mediators can convert astrocytes into a neurotoxic A1 phenotype in a variety of neurological diseases
1,2 . Development of agents that could inhibit the formation of A1 reactive astrocytes could be used to treat these diseases for which there are no disease-modifying therapies. Glucagon-like peptide-1 receptor (GLP1R) agonists have been indicated as potential neuroprotective agents for neurologic disorders such as Alzheimer's disease and Parkinson's disease3-13 . The mechanisms by which GLP1R agonists are neuroprotective are not known. Here we show that a potent, brain-penetrant long-acting GLP1R agonist, NLY01, protects against the loss of dopaminergic neurons and behavioral deficits in the α-synuclein preformed fibril (α-syn PFF) mouse model of sporadic Parkinson's disease14,15 . NLY01 also prolongs the life and reduces the behavioral deficits and neuropathological abnormalities in the human A53T α-synuclein (hA53T) transgenic mouse model of α-synucleinopathy-induced neurodegeneration16 . We found that NLY01 is a potent GLP1R agonist with favorable properties that is neuroprotective through the direct prevention of microglial-mediated conversion of astrocytes to an A1 neurotoxic phenotype. In light of its favorable properties, NLY01 should be evaluated in the treatment of Parkinson's disease and related neurologic disorders characterized by microglial activation.- Published
- 2018
- Full Text
- View/download PDF
36. Recent progress in dendrimer-based nanomedicine development.
- Author
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Kim Y, Park EJ, and Na DH
- Subjects
- Dendrimers chemistry, Humans, Nanomedicine trends, Neoplasms drug therapy, Virus Diseases drug therapy, Dendrimers therapeutic use, Drug Carriers chemistry, Drug Design, Nanomedicine methods
- Abstract
Dendrimers offer well-defined nanoarchitectures with spherical shape, high degree of molecular uniformity, and multiple surface functionalities. Such unique structural properties of dendrimers have created many applications for drug and gene delivery, nanomedicine, diagnostics, and biomedical engineering. Dendrimers are not only capable of delivering drugs or diagnostic agents to desired sites by encapsulating or conjugating them to the periphery, but also have therapeutic efficacy in their own. When compared to traditional polymers for drug delivery, dendrimers have distinct advantages, such as high drug-loading capacity at the surface terminal for conjugation or interior space for encapsulation, size control with well-defined numbers of peripheries, and multivalency for conjugation to drugs, targeting moieties, molecular sensors, and biopolymers. This review focuses on recent applications of dendrimers for the development of dendrimer-based nanomedicines for cancer, inflammation, and viral infection. Although dendrimer-based nanomedicines still face some challenges including scale-up production and well-characterization, several dendrimer-based drug candidates are expected to enter clinical development phase in the near future.
- Published
- 2018
- Full Text
- View/download PDF
37. Treatment Outcomes and Risk Factors for In-Hospital Mortality in Patients with Acute Aortic Occlusion.
- Author
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Na DH, Hwang D, Park S, Kim HK, and Huh S
- Abstract
Purpose: The aims of the present study are to determine the outcomes after acute aortic occlusion (AAO) and analyze the risk factors for in-hospital mortality., Materials and Methods: We retrospectively analyzed 24 patients who were diagnosed with AAO from 2002 to 2017 in our registered data. Demographic and radiologic characteristics of AAOs were retrospectively collected. Perioperative treatment outcomes including in-hospital mortality were also assessed and the risk factors of in-hospital mortality were analyzed., Results: The median symptom duration was 21 hours. Five patients had complete paraplegia and 10 patients (41.7%) were initially evaluated for central nervous system disorders instead of acute arterial occlusion. The etiology was determined to be aortoiliac thrombosis in 17 patients (70.8%) and embolic occlusion in 7. Surgical revascularization was performed in 23 patients, and one patient did not receive any treatment. The overall in-hospital mortality was 34.8% (8/23) and 30-day mortality was 26.1%. In the univariate analysis, age (P=0.040), preoperative renal insufficiency (serum creatinine over 1.5 mg/dL at the time of presentation) (P=0.008), postoperative acute kidney injury (need for dialysis or an increase in serum creatinine of >50.0% within 48 hours) (P=0.006), combined external iliac artery occlusion (P=0.019) and combined bilateral internal iliac artery occlusion (P=0.039) were associated with in-hospital mortality., Conclusion: A substantial number of AAO patients were initially evaluated for a central nervous system lesion, which led to a delay in diagnosis. Thus, vascular examinations should always be performed in every patient presenting with lower limb neurologic deficits. Age, perioperative renal function, and combined iliac artery occlusion were associated with the prognosis of AAOs., Competing Interests: Conflict of interest: None.
- Published
- 2018
- Full Text
- View/download PDF
38. PEGylated TRAIL ameliorates experimental inflammatory arthritis by regulation of Th17 cells and regulatory T cells.
- Author
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Park JS, Oh Y, Park O, Foss CA, Lim SM, Jo DG, Na DH, Pomper MG, Lee KC, and Lee S
- Subjects
- Animals, Arthritis, Experimental genetics, Arthritis, Experimental immunology, Arthritis, Experimental pathology, Cytokines blood, Cytokines genetics, Cytokines immunology, Knee Joint drug effects, Knee Joint immunology, Knee Joint pathology, Male, Mice, Inbred DBA, Polyethylene Glycols chemistry, Polyethylene Glycols pharmacology, Polyethylene Glycols therapeutic use, RNA, Messenger metabolism, T-Lymphocytes, Regulatory drug effects, T-Lymphocytes, Regulatory immunology, TNF-Related Apoptosis-Inducing Ligand chemistry, TNF-Related Apoptosis-Inducing Ligand pharmacology, TNF-Related Apoptosis-Inducing Ligand therapeutic use, Arthritis, Experimental drug therapy, Polyethylene Glycols administration & dosage, TNF-Related Apoptosis-Inducing Ligand administration & dosage
- Abstract
TNF-related apoptosis-inducing ligand (TRAIL) is a death ligand that can induce apoptosis in cells expressing its cognate death receptors (DRs). Previously, we demonstrated the therapeutic potential of recombinant human TRAIL in experimental rheumatoid arthritis (RA) models. However, the mechanisms of how DR-mediated apoptosis elicits these actions is not known. Here, we show that systemically administering a potent, long-acting PEGylated TRAIL (TRAIL
PEG ) is profoundly anti-rheumatic against two complementary experimental RA mouse models, collagen-induced arthritis (CIA) and collagen antibody-induced arthritis (CAIA), via targeting IL-17 secreting Th17 cells and regulatory T cells (Treg). Systemic administration of TRAILPEG after disease onset ameliorated the severity of inflammatory arthritis including arthritis indices, paw thickness, cartilage damage and neutrophil infiltration in both CIA and CAIA models. Additionally, the levels of inflammatory molecules (p-p65, ICAM-1, Cox-2, MMP3, and iNOS), pro-inflammatory cytokines (TNF-α, IL-1β, IFN-γ, IL-6, IL-17) and accumulation of activated macrophages were significantly reduced after the TRAILPEG treatment. Importantly, TRAILPEG decreased the number of pro-inflammatory Th17 cells in inflamed arthritic joints through TRAIL-induced apoptosis while increasing anti-inflammatory Treg population in vivo. These results suggest that TRAILPEG ameliorates autoimmunity by targeting the Th 17-Tregs axis, making it a promising candidate drug for the treatment of RA., (Copyright © 2017. Published by Elsevier B.V.)- Published
- 2017
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39. Reducing agent-free synthesis of curcumin-loaded albumin nanoparticles by self-assembly at room temperature.
- Author
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Safavi MS, Shojaosadati SA, Yang HG, Kim Y, Park EJ, Lee KC, and Na DH
- Subjects
- Animals, Antioxidants pharmacology, Cell Line, Mice, Neuroprotective Agents pharmacology, Particle Size, Reducing Agents, Temperature, Curcumin chemistry, Nanoparticles chemistry, Serum Albumin, Bovine chemistry
- Abstract
The purpose of this study was to prepare curcumin-loaded bovine serum albumin nanoparticles (CCM-BSA-NPs) by reducing agent-free self-assembly at room temperature. A 2
4 factorial design approach was used to investigate the CCM-BSA-NP preparation process at different pH values, temperatures, dithiothreitol amounts, and CCM/BSA mass ratios. Increasing the ionic strength enabled preparation of CCM-BSA-NPs at 25°C without reducing agent. CCM-BSA-NPs prepared under the optimized conditions at 25°C showed a particle size of 110±6nm, yield of 88.5%, and drug loading of 7.1%. The CCM-BSA-NPs showed strong antioxidant activity and neuroprotective effects in glutamate-induced mouse hippocampal neuronal HT22 cells. This study suggests that ionic strength can be a key parameter affecting the preparation of albumin-based NPs., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
- Full Text
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40. Dual Functioned Pegylated Phospholipid Micelles Containing Cationic Antimicrobial Decapeptide for Treating Sepsis.
- Author
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Lee W, Park EJ, Min G, Choi J, Na DH, and Bae JS
- Subjects
- Animals, Anti-Infective Agents therapeutic use, Human Umbilical Vein Endothelial Cells cytology, Human Umbilical Vein Endothelial Cells drug effects, Humans, Mice, Micelles, Phosphatidylethanolamines chemistry, Phospholipids chemistry, Sepsis drug therapy, Anti-Infective Agents chemistry, Anti-Infective Agents pharmacology, Polyethylene Glycols chemistry
- Abstract
Despite intensive investigation of molecular mechanisms underlying the pathogenesis of sepsis, many aspects of sepsis remain unresolved; this hampers the development of appropriate therapeutics. In the present study, we developed a biologic nanomedicine containing a cationic antimicrobial decapeptide KSLW (KKVVFWVKFK), self-associated with biocompatible and biodegradable PEGylated phospholipid micelles (PLM), and analyzed its efficacy for treating sepsis. KSLW was modified with polyethylene glycol (PEG)-aldehyde or was conjugated with distearoylphosphatidylethanolamine (DSPE) -PEG-aldehyde. We compared the antibacterial and antiseptic effects of PEG-KSLW and PLM-KSLW with those of unmodified KSLW both in vitro and in vivo . We found that the PLM-KSLW improved the survival rate of sepsis mouse models without undesired immune responses, and inhibited lipopolysaccharide (LPS)-induced severe vascular inflammatory responses in human umbilical vein endothelial cells compared with unmodified KSLW or PEG-KSLW. Furthermore, PLM-KSLW dramatically reduced the bacterial count and inhibited bacterial growth. We also found a new role of PLM-KSLW in tightening vascular barrier integrity by binding to the glycine/tyrosine-rich domain of occludin (OCLN). Our results showed that PLM-KSLW had a more effective antiseptic effect than KSLW or PEG-KSLW, possibly because of its high affinity toward OCLN. Moreover, PLM-KSLW could be potentially used to treat severe vascular inflammatory diseases, including sepsis and septic shock., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.
- Published
- 2017
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41. A first case of high-flow nasal cannula oxygen therapy in patients with pulmonary tumor thrombotic microangiopathy.
- Author
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Joo H, Na DH, Seung J, Kim TY, Min GJ, and Rhee CK
- Subjects
- Administration, Inhalation, Adult, Breast Neoplasms pathology, Cannula, Carcinoma, Ductal, Breast secondary, Fatal Outcome, Female, Humans, Lung Neoplasms secondary, Oxygen Inhalation Therapy instrumentation, Perfusion Imaging, Thrombotic Microangiopathies diagnostic imaging, Thrombotic Microangiopathies etiology, Thrombotic Microangiopathies pathology, Tomography, X-Ray Computed, Treatment Outcome, Breast Neoplasms complications, Carcinoma, Ductal, Breast complications, Lung Neoplasms complications, Neoplastic Cells, Circulating pathology, Oxygen Inhalation Therapy methods, Thrombotic Microangiopathies therapy
- Published
- 2017
- Full Text
- View/download PDF
42. Nanostructured glycan architecture is important in the inhibition of influenza A virus infection.
- Author
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Kwon SJ, Na DH, Kwak JH, Douaisi M, Zhang F, Park EJ, Park JH, Youn H, Song CS, Kane RS, Dordick JS, Lee KB, and Linhardt RJ
- Subjects
- Animals, Dogs, Female, Madin Darby Canine Kidney Cells, Mice, Mice, Inbred BALB C, Orthomyxoviridae Infections metabolism, Orthomyxoviridae Infections pathology, Dendrimers chemistry, Dendrimers pharmacology, Influenza A Virus, H1N1 Subtype metabolism, Nanostructures chemistry, Nanostructures therapeutic use, Orthomyxoviridae Infections drug therapy, Polysaccharides chemistry, Polysaccharides pharmacology
- Abstract
Rapid change and zoonotic transmission to humans have enhanced the virulence of the influenza A virus (IAV). Neutralizing antibodies fail to provide lasting protection from seasonal epidemics. Furthermore, the effectiveness of anti-influenza neuraminidase inhibitors has declined because of drug resistance. Drugs that can block viral attachment and cell entry independent of antigenic evolution or drug resistance might address these problems. We show that multivalent 6'-sialyllactose-polyamidoamine (6SL-PAMAM) conjugates, when designed to have well-defined ligand valencies and spacings, can effectively inhibit IAV infection. Generation 4 (G4) 6SL-PAMAM conjugates with a spacing of around 3 nm between 6SL ligands (S3-G4) showed the strongest binding to a hemagglutinin trimer (dissociation constant of 1.6 × 10
-7 M) and afforded the best inhibition of H1N1 infection. S3-G4 conjugates were resistant to hydrolysis by H1N1 neuraminidase. These conjugates protected 75% of mice from a lethal challenge with H1N1 and prevented weight loss in infected animals. The structure-based design of multivalent nanomaterials, involving modulation of nanoscale backbone structures and number and spacing between ligands, resulted in optimal inhibition of IAV infection. This approach may be broadly applicable for designing effective and enduring therapeutic protection against human or avian influenza viruses.- Published
- 2017
- Full Text
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43. Characterization of the Reversed-Phase Chromatographic Behavior of PEGylated Peptides Based on the Poly(ethylene glycol) Dispersity.
- Author
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Park EJ and Na DH
- Subjects
- Chromatography, High Pressure Liquid, Peptides isolation & purification, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Chromatography, Reverse-Phase, Peptides analysis, Peptides chemistry, Polyethylene Glycols chemistry
- Abstract
The separation mechanism of PEGylated peptides in reversed-phase high-performance liquid chromatography (RP-HPLC) is complex, because the PEGylated molecules exhibit physicochemical properties that are different from those of the parent molecules and have heterogeneous structure. Since most separation studies have focused on the hydrophobicity of the peptide relative to poly(ethylene glycol) (PEG), the role of PEG in the separation of PEGylated peptides on RP-HPLC is not clear. To elucidate the effect of the attached PEG on the retention of PEGylated peptides on RP-HPLC, the mono-PEGylated forms of collagen pentapeptide and octreotide were fractionated drop-by-drop from the outlet of the HPLC system and each drop was subjected to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). This approach demonstrated that the dispersity of the attached PEG leads to the peak broadness of PEGylated peptides in RP-HPLC and the elution order inside the HPLC peak of PEGylated peptides was dependent on the attached PEG chain length. The retention time of PEGylated peptide increased as the attached PEG chain increased in length. When uniform PEG was conjugated to octreotide, its well-resolved positional isomers of the mono-PEGylated forms showed narrow peaks comparable to native peptide peak under the same HPLC conditions, which confirmed the effect of the attached PEG dispersity on the chromatographic behavior of PEGylated peptides. In conclusion, this study indicates that the chromatographic behavior of PEGylated peptides is affected by the PEG chain length dispersity as well as the peptide's hydrophobicity.
- Published
- 2016
- Full Text
- View/download PDF
44. Exendins and exendin analogs for diabetic therapy: a patent review (2012-2015).
- Author
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Park EJ, Lim SM, Lee KC, and Na DH
- Subjects
- Animals, Delayed-Action Preparations, Diabetes Mellitus, Type 2 physiopathology, Drug Design, Exenatide, Humans, Hypoglycemic Agents chemistry, Hypoglycemic Agents pharmacology, Medication Adherence, Patents as Topic, Peptides chemistry, Peptides pharmacology, Venoms chemistry, Venoms pharmacology, Diabetes Mellitus, Type 2 drug therapy, Hypoglycemic Agents administration & dosage, Peptides administration & dosage, Venoms administration & dosage
- Abstract
Introduction: Since exendin-4 (exenatide) was approved for diabetes therapy in 2005, several exendin analogs have been developed for the treatment of type 2 diabetes mellitus. As exenatide is a relatively short-acting injectable agent, major approaches have focused on developing long-acting exendin analogs to improve patient compliance and convenience., Areas Covered: In this review, the authors report on patents related to exendins and exendin analogs from 2012 to 2015. The patents have been divided into three categories based on the technologies used to develop the new chemical entities: 1) chemical bioconjugate analogs; 2) recombinant fusion protein analogs; and 3) multifunctional peptide analogs., Expert Opinion: Recently, research on exendins and their analogs has grown significantly, leading to the development of long-acting analogs and multifunctional peptides. While long-acting injectable agents are still the major products in the pharmaceutical industry, a significant growth is expected in the development of orally available exendins.
- Published
- 2016
- Full Text
- View/download PDF
45. Trimeric PEG-Conjugated Exendin-4 for the Treatment of Sepsis.
- Author
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Lee W, Park EJ, Kwak S, Lee KC, Na DH, and Bae JS
- Subjects
- Animals, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Exenatide, Human Umbilical Vein Endothelial Cells drug effects, Humans, Male, Maleimides chemistry, Mice, Mice, Inbred C57BL, Peptides pharmacology, Peptides therapeutic use, Protein Binding, Protein Stability, Venoms pharmacology, Venoms therapeutic use, Anti-Bacterial Agents chemistry, Peptides chemistry, Polyethylene Glycols chemistry, Sepsis drug therapy, Venoms chemistry
- Abstract
Exendin-4 (EX4), a glucagon-like peptide-1 receptor (GLP-1R) agonist that regulates blood glucose levels, has been used in the management of type-2 diabetes mellitus. EX4 can be PEGylated to improve its antidiabetic effects by enhancing its stability and extending the circulation half-life. Here, to determine whether PEGylated EX4 is effective for the treatment of sepsis, C-terminal thiol-specific PEGylated EX4s with linear maleimide-PEG-2K, -5K, -20K and trimeric maleimide-PEG-50K (hereafter referred to as EX4-2K, EX4-5K, EX4-20K, and EX4-50K, respectively) were prepared, and their antiseptic responses were investigated. These PEGylated EX4s reduced cecal ligation and puncture (CLP)-induced organ injury by decreasing hyperpermeability, and suppressing interactions between leukocytes and endothelial cells. The binding avidity and stability of EX4-50K toward GLP-1R were superior to that of wild-type EX4, as was the circulation half-life of EX4-50K. In addition, the antiseptic effects of EX4-50K were superior to those of other PEGylated EX4s, which may be attributed to enhanced proteolytic stability, longer circulation half-life, and higher receptor-binding affinity of EX4-50K due to its trimeric PEG structure. Therefore, EX4-50K may decrease CLP-induced septic mortality in vivo. There are currently neither effective preventatives against nor treatment options for sepsis; our results show that EX4-50K has the potential to treat sepsis.
- Published
- 2016
- Full Text
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46. Delivery of tumor-homing TRAIL sensitizer with long-acting TRAIL as a therapy for TRAIL-resistant tumors.
- Author
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Oh Y, Swierczewska M, Kim TH, Lim SM, Eom HN, Park JH, Na DH, Kim K, Lee KC, Pomper MG, and Lee S
- Subjects
- Animals, Antineoplastic Agents chemistry, Antineoplastic Agents pharmacokinetics, Apoptosis drug effects, Caspases metabolism, Cell Survival drug effects, Chemistry, Pharmaceutical, Colonic Neoplasms genetics, Colonic Neoplasms metabolism, Colonic Neoplasms pathology, Enzyme Activation, HCT116 Cells, HEK293 Cells, HT29 Cells, Half-Life, Humans, Hyaluronic Acid chemistry, Injections, Intravenous, Mice, Inbred BALB C, Mice, Nude, Polyethylene Glycols chemistry, RNA Interference, Receptors, TNF-Related Apoptosis-Inducing Ligand genetics, Receptors, TNF-Related Apoptosis-Inducing Ligand metabolism, TNF-Related Apoptosis-Inducing Ligand chemistry, TNF-Related Apoptosis-Inducing Ligand pharmacokinetics, Transfection, Xenograft Model Antitumor Assays, Antineoplastic Agents administration & dosage, Antineoplastic Combined Chemotherapy Protocols administration & dosage, Colonic Neoplasms drug therapy, Doxorubicin administration & dosage, Drug Resistance, Neoplasm drug effects, TNF-Related Apoptosis-Inducing Ligand administration & dosage
- Abstract
Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) has attracted great interest as a cancer therapy because it selectively induces death receptor (DR)-mediated apoptosis in cancer cells while sparing normal tissue. However, recombinant human TRAIL demonstrates limited therapeutic efficacy in clinical trials, possibly due to TRAIL-resistance of primary cancers and its inherent short half-life. Here we introduce drug delivery approaches to maximize in vivo potency of TRAIL in TRAIL-resistant tumor xenografts by (1) extending the half-life of the ligand with PEGylated TRAIL (TRAILPEG) and (2) concentrating a TRAIL sensitizer, selected from in vitro screening, in tumors via tumor-homing nanoparticles. Antitumor efficacy of TRAILPEG with tumor-homing sensitizer was evaluated in HCT116 and HT-29 colon xenografts. Western blot, real-time PCR, immunohistochemistry and cell viability assays were employed to investigate mechanisms of action and antitumor efficacy of the combination. We discovered that doxorubicin (DOX) sensitizes TRAIL-resistant HT-29 colon cancer cells to TRAIL by upregulating mRNA expression of DR5 by 60% in vitro. Intravenously administered free DOX does not effectively upregulate DR5 in tumor tissues nor demonstrate synergy with TRAILPEG in HT-29 xenografts, but rather introduces significant systemic toxicity. Alternatively, when DOX was encapsulated in hyaluronic acid-based nanoparticles (HAC/DOX) and intravenously administered with TRAILPEG, DR-mediated apoptosis was potentiated in HT-29 tumors by upregulating DR5 protein expression by 70% and initiating both extrinsic and intrinsic apoptotic pathways with reduced systemic toxicity compared to HAC/DOX or free DOX combined with TRAILPEG (80% vs. 40% survival rate; 75% vs. 34% tumor growth inhibition). This study demonstrates a unique approach to overcome TRAIL-based therapy drawbacks using sequential administration of a tumor-homing TRAIL sensitizer and long-acting TRAILPEG., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
47. Mono-lithocholated exendin-4-loaded glycol chitosan nanoparticles with prolonged antidiabetic effects.
- Author
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Son S, Lim SM, Chae SY, Kim K, Park EJ, Lee KC, and Na DH
- Subjects
- Animals, Chitosan chemistry, Drug Liberation, Exenatide, Hypoglycemic Agents administration & dosage, Hypoglycemic Agents chemistry, Hypoglycemic Agents therapeutic use, Lysine chemistry, Mice, Nanoparticles chemistry, Particle Size, Peptides chemistry, Succinimides chemistry, Venoms chemistry, Chitosan administration & dosage, Diabetes Mellitus, Type 2 drug therapy, Drug Carriers administration & dosage, Drug Carriers chemistry, Lithocholic Acid chemistry, Nanoparticles administration & dosage, Peptides administration & dosage, Peptides therapeutic use, Venoms administration & dosage, Venoms therapeutic use
- Abstract
Hydrophobically modified glycol chitosan (HGC) nanoparticles loaded with mono-lithocholic acid-conjugated exendin-4 at the Lys(27) residue (LAM1-Ex4) were prepared and characterized by particle size measurement, proteolytic stability, in vitro drug-release profile, and in vivo antidiabetic effects in a db/db diabetic mouse model. Compared with Ex-4-loaded HGC nanoparticles (Ex4/HGC NPs) prepared as a control, LAM1-Ex4-loaded HGC nanoparticles (LAM1-Ex4/HGC NPs) showed improved drug-loading efficiency, small particle size, enhanced resistance against proteolytic digestion, and an extended in vitro drug release profile. These findings may be attributable to the strong hydrophobic interaction between LAM1-Ex4 and the inner core of HGC. Furthermore, LAM1-Ex4/HGC NPs showed prolonged hypoglycemic efficacy in db/db mice, lasting 1 week after a single subcutaneous administration. The present study demonstrated that LAM1-Ex4/HGC NPs have considerable potential as a long-acting sustained-release antidiabetic system for type 2 diabetes., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
48. A Double-Chambered Protein Nanocage Loaded with Thrombin Receptor Agonist Peptide (TRAP) and γ-Carboxyglutamic Acid of Protein C (PC-Gla) for Sepsis Treatment.
- Author
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Lee W, Seo J, Kwak S, Park EJ, Na DH, Kim S, Lee YM, Kim IS, and Bae JS
- Subjects
- 1-Carboxyglutamic Acid chemistry, Animals, Anti-Inflammatory Agents chemistry, Collagenases metabolism, Disease Models, Animal, Drug Delivery Systems, Ferritins chemistry, Fetal Blood, Human Embryonic Stem Cells, Humans, Leukocytes drug effects, Leukocytes physiology, Lipopolysaccharides, Male, Mice, Inbred C57BL, Protein C chemistry, Receptor, PAR-1 metabolism, Sepsis metabolism, Sepsis mortality, Anti-Inflammatory Agents administration & dosage, Nanostructures chemistry, Peptide Fragments administration & dosage, Protein C administration & dosage, Receptors, Thrombin agonists, Sepsis drug therapy
- Abstract
New protein nanocages are designed bearing two functional proteins, γ-carboxyglutamic acid of protein C (PC-Gla) and thrombin receptor agonist peptide (TRAP), and have an anti-septic response. These nanoparticles reduce sepsis-induced organ injury and septic mortality in vivo. Noting that there are currently no medications for severe sepsis, these results show that novel nanoparticles can be used to treat sepsis., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2015
- Full Text
- View/download PDF
49. Difference in microchip electrophoretic mobility between partially and fully PEGylated poly(amidoamine) dendrimers.
- Author
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Park EJ and Na DH
- Subjects
- Biocompatible Materials, Dendrimers chemistry, Drug Carriers, Electrophoresis, Capillary, Electrophoresis, Microchip, Molecular Weight, Polyamines chemistry, Polyethylene Glycols chemistry, Republic of Korea, Spectrometry, Fluorescence, Surface Properties, Dendrimers analysis, Polyamines analysis, Polyethylene Glycols analysis
- Abstract
The objective of this study was to investigate the difference in electrophoretic mobility between partially and fully poly(ethylene glycol)-conjugated poly(amidoamine) dendrimers (part-PEG-PAMAM and full-PEG-PAMAM, respectively) using a microchip capillary gel electrophoresis (MCGE). While MCGE allowed size-based separation of PEG-PAMAMs prepared with monomethoxy PEG-nitrophenyl carbonate, full-PEG-PAMAMs migrated slower than part-PEG-PAMAMs that were similar in size or larger. When the measured molecular weights obtained from MCGE analysis and the calculated molecular weights were plotted, each part-PEG-PAMAM and full-PEG-PAMAM showed correlation coefficients greater than 0.98. This study indicates that MCGE would be useful for characterizing PEG-PAMAMs with different PEGylation degrees., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
50. Anti-Inflammatory Effects of Lysozyme Against HMGB1 in Human Endothelial Cells and in Mice.
- Author
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Lee W, Ku SK, Na DH, and Bae JS
- Subjects
- Animals, Chickens, Dose-Response Relationship, Drug, Endothelium, Vascular metabolism, Human Umbilical Vein Endothelial Cells drug effects, Human Umbilical Vein Endothelial Cells metabolism, Humans, Male, Mice, Mice, Inbred C57BL, Anti-Inflammatory Agents pharmacology, Endothelium, Vascular drug effects, HMGB1 Protein antagonists & inhibitors, HMGB1 Protein metabolism, Muramidase pharmacology
- Abstract
High mobility group box 1 (HMGB1) was recently shown to be an important extracellular mediator of severe vascular inflammatory disease, sepsis. Lysozyme protects us from the ever-present danger of bacterial infection and binds to bacterial lipopolysaccharide (LPS) with a high affinity. Here, we show, for the first time, the anti-septic effects of lysozyme in HMGB1-mediated inflammatory responses in vitro and in vivo. The data showed that lysozyme posttreatment suppressed LPS-mediated release of HMGB1 and HMGB1-mediated cytoskeletal rearrangement. Lysozyme also inhibited HMGB1-mediated hyperpermeability and leukocyte migration in human endothelial cells. In addition, lysozyme inhibited the HMGB1-mediated activation of Akt, nuclear factor-κB (NF-κB), extracellular regulated kinases (ERK) 1/2 and production of interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), and chemoattractant protein-1 (MCP-1) in HUVECs. Furthermore, lysozyme reduced the cecal ligation and puncture (CLP)-induced release of HMGB1, migration of leukocytes, septic mortality, and pulmonary damage in mice. Collectively, these results suggest lysozyme as a candidate therapeutic agent for the treatment of vascular inflammatory diseases via inhibition of the HMGB1 signaling pathway.
- Published
- 2015
- Full Text
- View/download PDF
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