Publications by authors named "Kyoung-Jin Lee"

Tetrahydrobiopterin (BH4) expression is normally strictly controlled; however, its intracellular levels increase considerably following nerve damage. GTP cyclohydrolase I (GCH1) plays a crucial role in regulating BH4 concentration, with an upregulation observed in the dorsal root ganglion in cases of neuropathic pain. In this study, we aimed to develop and evaluate the clinical potential of an RNA interference-based adeno-associated virus (AAV) targeting GCH1 across various species to decrease BH4 levels and, consequently, alleviate neuropathic pain symptoms.

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Soft peristaltic pumps, which use soft ring actuators instead of mechanical pistons or rollers, offer advantages in transporting liquids with non-uniform solids, such as slurry, food, and sewage. Recent advances in 3D printing with flexible thermoplastic polyurethane (TPU) present the potential for single-step fabrication of these pumps, distinguished from handcrafted, multistep traditional silicone casting methods. However, because of the relatively high hardness of TPU, TPU-based soft peristaltic pumps contract insufficiently and thus cannot perform as well as silicone-based ones.

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Since water is an essential resource in various fields, it requires constant monitoring. Chlorophyll-a concentration is a crucial indicator of water quality and can be used to monitor water quality. In this study, we developed methods to forecast chlorophyll-a concentrations in real-time using hyperspectral data on IoT platform and various machine learning algorithms.

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In efforts towards eliminating malaria, a discovery program was initiated to identify a novel antimalarial using KAF156 as a starting point. Following the most recent TCP/TPP guidelines, we have identified mCMQ069 with a predicted single oral dose for treatment (∼40-106 mg) and one-month chemoprevention (∼96-216 mg). We have improved unbound MPC and predicted human clearance by 18-fold and 10-fold respectively when compared to KAF156.

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Adult hippocampal neurogenesis plays a pivotal role in maintaining cognitive brain function. However, this process diminishes with age, particularly in patients with neurodegenerative disorders. While small, non-coding microRNAs (miRNAs) are crucial for hippocampal neural stem (HCN) cell maintenance, their involvement in neurodegenerative disorders remains unclear.

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Background: Elastomeric pumps have a curved infusion rate profile over infusion time. Chemically driven pumps can overcome such limitations of elastomeric pumps and infuse constantly. However, studies on the pharmacokinetic benefit of chemically-driven pumps are insufficient.

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Article Synopsis
  • - Myeloid-derived suppressor cells (MDSCs) are immunosuppressive cells originating from bone marrow, key in the tumor environment, but how they move from the bone marrow to tumors is not fully understood.
  • - The study found that activation of bone marrow stromal cells by parathyroid hormone (PTH) triggers the release of monocytic MDSCs from the bone marrow, but this does not increase their immunosuppressive function.
  • - Activation of PTH1R in osteoblasts leads to the production of VEGF-A and IL6, which affects MDSC behavior by triggering specific signaling pathways that result in MDSC detachment from osteoblasts, contributing to their mobilization.
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Daphnia magna is an important organism in ecotoxicity studies because it is sensitive to toxic substances and easy to culture in laboratory conditions. Its locomotory responses as a biomarker are highlighted in many studies. Over the last several years, multiple high-throughput video tracking systems have been developed to measure the locomotory responses of Daphnia magna.

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Myeloid-derived suppressor cells (MDSCs) and M2 macrophages in the tumor microenvironment contribute to tumor progression by inducing immune tolerance to tumor antigens and cancer cells. Metformin, one of the most common diabetes drugs, has shown anti-inflammatory and anti-tumor effects. However, the effects of metformin on inflammatory cells of the tumor microenvironment and its underlying mechanisms remain unclarified.

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In addition to laser photocoagulation, therapeutic interventions for diabetic retinopathy (DR) have heretofore consisted of anti-VEGF drugs, which, besides drawbacks inherent to the treatments themselves, are limited in scope and may not fully address the condition's complex pathophysiology. This is because DR is a multifactorial condition, meaning a gene therapy focused on a target with broader effects, such as the mechanistic target of rapamycin (mTOR), may prove to be the solution in overcoming these concerns. Having previously demonstrated the potential of a mTOR-inhibiting shRNA packaged in a recombinant adeno-associated virus to address a variety of angiogenic retinal diseases, here we explore the effects of rAAV2-shmTOR-SD in a streptozotocin-induced diabetic mouse model.

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A spherical silica aerogel powder with hydrophobic surfaces displaying a water contact angle of 147° was synthesized from a water glass-in-hexane emulsion through ambient pressure drying. Water glass droplets containing acetic acid and ethyl alcohol were stabilized in -hexane with a surfactant. Gelation was performed by heating the droplets, followed by solvent exchange and surface modification using a hexamethyldisilazane (HMDS)/-hexane solution.

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Translationally controlled tumor protein (TCTP) is expressed in many tissues, particularly in human tumors. It plays a role in malignant transformation, apoptosis prevention, and DNA damage repair. The signaling mechanisms underlying TCTP regulation in cancer are only partially understood.

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The keratinocytes in UV-irradiated skin produce and secrete α-melanocyte-stimulating hormone. α-Melanocyte-stimulating hormone upregulates the expression of MITF in melanocytes through the cAMP‒protein kinase A‒CREB signaling pathway. Thereafter, MITF induces the expression of melanogenic genes, including the tyrosinase gene TYR and TYRP-1 and TYRP-2 genes, which leads to the synthesis and accumulation of melanin.

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Solid oxide electrolyzer cells with an Ni-Fe-yttria-stabilized zirconia (Ni-Fe-YSZ) hydrogen electrode as the cathode, lanthanum strontium ferrite (LSCF)-gadolinia-doped ceria (GDC) air electrode as the anode, and YSZ as the electrolyte were fabricated, and the oxidation protection effect of sacrificial Fe particles was investigated. X-ray diffraction analysis indicated that Ni was protected from oxidation under a water vapor atmosphere by sacrificial Fe. Scanning electron microscopy observations suggested that the Ni particles accumulated in the Ni-YSZ hydrogen electrode, which might have been associated with the partial oxidation of Ni during cell operation at 700 °C in 50% H₂O/15% H₂/35% Ar atmosphere.

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Background & Aims: The benefits of farnesoid X receptor (FXR) agonists in patients with non-alcoholic steatohepatitis (NASH) have been validated, although improvements in efficacy and/or tolerability remain elusive. Herein, we aimed to assess the performance of a structurally optimized FXR agonist in patients with NASH.

Methods: In this 12-week, randomized, placebo-controlled study, we evaluated MET409 - a non-bile acid agonist with a unique chemical scaffold - in patients with NASH.

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The epidermal growth factor receptor (EGFR), a member of ErbB receptor tyrosine kinase (RTK) family, is activated through growth factor-induced reorganization of the actin cytoskeleton and subsequent dimerization. We herein explored the molecular mechanism underlying the suppression of ligand-induced EGFR dimerization by CD99 agonists and its relevance to tumor growth in vivo. Epidermal growth factor (EGF) activated the formation of c-Src/focal adhesion kinase (FAK)-mediated intracellular complex and subsequently induced RhoA-and Rac1-mediated actin remodeling, resulting in EGFR dimerization and endocytosis.

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As a new class of cancer therapeutic agents, oncolytic viruses (OVs) have gained much attention not only due to their ability to selectively replicate in and lyse tumor cells, but also for their potential to stimulate antitumor immune responses. As a result, there is an increasing need for in vitro modeling systems capable of recapitulating the 3D physiological tumor microenvironment. Here, we investigated the potential of our recently developed microphysiological system (MPS), featuring a vessel-like channel to reflect the in vivo tumor microenvironment and serving as culture spaces for 3D multicellular tumor spheroids (MCTSs).

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Neoadjuvant radiotherapy has become an important therapeutic option for colorectal cancer (CRC) patients, whereas complete tumor response is observed only in 20-30% patients. Therefore, the development of diagnostic probe for radio-resistance is important to decide an optimal treatment timing and strategy for radiotherapy-resistant CRC patients. In this study, using the patient-derived xenograft (PDX) mouse model established with a radio-resistant CRC tumor tissue, we found low-density lipoprotein receptor-related protein-1 (LRP-1) as a radio-resistant marker protein induced by initial-dose radiation in radio-resistant CRC tumors.

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Current diagnosis of bone metastasis (BM) in breast cancer relies on structural changes of bone that occur only in the advanced stage. A sensitive biomarker for detecting early progression of bone metastasis is urgently required. We performed clinical and preclinical studies to investigate diagnostic value of circulating osteocalcin-positive cells (cOC) in breast cancer bone metastasis.

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Replicable oncolytic viruses (OVs) induce tumor cell lysis and release viral progeny. The released progeny virions and cell debris can spread within surrounding tumor cells or blood vessels. These released molecules may also induce bystander damage in additional tumor cells through spreading within surrounding tumor cells or blood vessels.

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Immune reactions are controlled by the delicate spatiotemporal orchestration of multiple cells communicating by cytokines. Studies of cytokines that began with the discovery of IFN focused on positive regulatory mechanisms that induce secretion in response to harmful stimuli. However, there is a growing awareness that negative regulatory mechanisms that stop secretion of cytokines at specific times and spaces are also important for a successful immune reaction.

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Purpose: Recent studies have shown that inhibitors of the mechanistic target of rapamycin (mTOR) play important roles in proliferating endothelial cells within the retinal vasculature. Here we explore the effects of inhibiting mTOR as a potential gene therapeutic against pathological retinal angiogenesis in a rat model of oxygen-induced retinopathy (OIR).

Methods: Sprague-Dawley pups were used to generate the OIR model, with a recombinant adeno-associated virus expressing an shRNA (rAAV2-shmTOR-GFP) being administered via intravitreal injection on returning the rats to normoxia, with appropriate controls.

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Background: Steady concentration peritoneal dialysis (SCPD), which maintains transperitoneal osmotic gradient by infusing 50% glucose solution throughout the dwell time, has been proposed as a potent treatment for peritoneal dialysis (PD) patients with fluid overload. However, SCPD has yet to be explored theoretically. Here, we investigated SCPD via computer simulations.

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Lithium-ion conducting nanocomposite solid electrolytes were synthesized from polyethylene oxide (PEO), poly(methyl methacrylate) (PMMA), LiClO₄, and LiAl0.3Ti(PO4)₃ (LATP) ceramic particles. The synthesized nanocomposite electrolyte consisted of LATP particles and an amorphous polymer.

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CeO₂-promoted Ni/Al₂O₃ catalysts were fabricated by impregnation. The effects of the CeO₂ promotion and impregnation order on the microstructural evolution and catalytic durability were investigated for methane steam reforming. The CeO₂-promoter nanoparticles resulted in good dispersion and reduced particle size of Ni catalysts.

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