Publications by authors named "Seung-Wook Ryu"

Contact-based pericellular interactions play important roles in cancer progression via juxtacrine signaling pathways. The present study revealed that hypoxia-inducible factor-1α (HIF-1α), induced even in non-hypoxic conditions by cell-to-cell contact, was a critical cue responsible for the malignant characteristics of glioblastoma multiforme (GBM) cells through Notch1 signaling. Densely cultured GBM cells showed enhanced viability and resistance to temozolomide (TMZ) compared to GBM cells at a low density.

View Article and Find Full Text PDF
Article Synopsis
  • The development of therapeutic exosomes for commercialization involves multiple stages, including manufacturing, characterization, and formulation, all while adhering to Good Manufacturing Practice (GMP) and regulatory standards.
  • Exosomes, which are small extracellular vesicles, hold promise as novel treatments due to their ability to deliver genetic or bioactive materials to cells, but challenges exist in creating clinical-grade versions.
  • Key hurdles in manufacturing include cell line development, cell culture, purification processes, and the establishment of GMP facilities, requiring ongoing communication between pharmaceutical companies and regulatory agencies.
View Article and Find Full Text PDF

BACKGROUND Malignant disease is a common etiology of superior vena cava syndrome (SVCS). Being a medical emergency, it often requires rapid diagnostic evaluation and therapy. Transcaval biopsy and endovascular stenting in a single-setting has been described, but only in a handful of cases.

View Article and Find Full Text PDF

Extramedullary plasmacytomas are rare and can occur at any site. The imaging results are often nonspecific. This report highlights the radiographic, sonographic and cross-sectional imaging features of extramedullary plasmacytomas.

View Article and Find Full Text PDF

One-dimensional (1D) nanowires (NWs) and two-dimensional (2D) thin films of Ni were deposited on highly ordered pyrolytic graphite (HOPG) by atomic layer deposition (ALD), using NH as a counter reactant. Thermal ALD using NH gas forms 1D NWs along step edges, while NH plasma enables the deposition of a continuous 2D film over the whole surface. The lateral and vertical growth rates of the Ni NWs are numerically modeled as a function of the number of ALD cycles.

View Article and Find Full Text PDF

Male breast cancers (MBC) are rare, accounting for <1% of all breast cancers. The use of magnetic resonance imaging (MRI) for male breast cancer is not generally indicated. We present an unusual case where conventional imaging for a suspected MBC was equivocal and MRI was required to assist in diagnosis.

View Article and Find Full Text PDF

Nanoparticle-mediated delivery of functional macromolecules is a promising method for treating a variety of human diseases. Among nanoparticles, cell-derived exosomes have recently been highlighted as a new therapeutic strategy for the in vivo delivery of nucleotides and chemical drugs. Here we describe a new tool for intracellular delivery of target proteins, named 'exosomes for protein loading via optically reversible protein-protein interactions' (EXPLORs).

View Article and Find Full Text PDF

Glioblastoma multiforme (GBM) is the most common and aggressive type of primary brain tumor with grave prognosis. Despite the growing understanding of the complex signaling networks responsible for the initiation and progression of GBM, many experimental therapies have fallen short of their treatment goals. In the present study, we investigated the novel molecular mechanisms responsible for synergistic action of temozolomide (TMZ) and anti-VEGF therapy in GBM cells.

View Article and Find Full Text PDF

Ginsenosides, the major bio-active ingredients included in Panax ginseng, have been known for the hair growth activity and used to treat patients who suffer from hair loss; however, the detailed mechanisms of this action are still largely unknown. This study was conducted to investigate the molecular and cellular mechanisms responsible for hair growth promoting effect of ginsenoside Re (GRe) in vitro and in vivo. Different doses of minoxidil and GRe were administered topically to the back regions of nude mice for up to 45 days, and hair shaft length and hair cycles were determined for hair promoting activities.

View Article and Find Full Text PDF

High-intensity femtosecond lasers have recently been used to irreversibly disrupt nanoscale structures, such as intracellular organelles, and to modify biological functions in a reversible manner: so-called nanosurgery and biophotomodulation. Femtosecond laser pulses above the threshold intensity sufficient for reversible biophotomodulation can cause irreversible changes in the irradiated cell, eventually leading to cell death. Here, we demonstrated that cytosolic irradiation with a femtosecond laser produced intrinsic cascades of reactive oxygen species (ROS), which led to rapid apoptosis-like cell death via a caspase and poly (ADP-ribose) polymerase 1 (PARP-1) signaling pathway.

View Article and Find Full Text PDF
Article Synopsis
  • Dendritic cells help shape whether naïve T cells become Th1 or Th2 types, influencing immune responses.
  • The study found that HspX from Mycobacterium tuberculosis increases pro-inflammatory cytokines and T-bet gene expression while decreasing anti-inflammatory IL-13 and GATA-3, suggesting a shift towards a Th1 response.
  • HspX also reduced asthma symptoms in mice by decreasing regulatory T cells and increasing eosinophils in the lungs, indicating its potential as a therapeutic target for asthma treatment.
View Article and Find Full Text PDF

As a potent immune regulator, heat shock protein 70 derived from Mycobacterium tuberculosis (Mtb Hsp70) has adjuvant effect and activates immune cells such as macrophages and dendritic cells (DCs). Although Toll-like receptors (TLRs) are known to involve in DCs activation by Mtb Hsp70, there is still a controversy and the underlying mechanism is not well understood. In this study, we examined whether TRIF and MyD88, the core adaptor molecules for TLRs signaling, regulate Mtb Hsp70-induced DCs activation.

View Article and Find Full Text PDF

Heat shock protein 70 from Mycobacterium tuberculosis (Mtb Hsp70) has been known to modulate immune response including dendritic cell activation. Muramyl dipeptide (MDP) is an immunoreactive derivative of peptidoglycan from all Gram-negative and Gram-positive bacteria and recognized to be responsible for function of Freund's complete adjuvant. In this study, we evaluated effect of MDP on in vitro activation of bone marrow derived dendritic cells (BMDCs) and in vivo production of cytokines and chemokines induced by Mtb Hsp70.

View Article and Find Full Text PDF

The shape and activity of mitochondria are tightly regulated by fusion and fission processes that are essential for maintaining normal cellular function. However, little is known about the involvement of mitochondrial dynamics in the development of the immune system. In this study, we demonstrate that mitochondrial dynamics play a role in the differentiation and migration of immature dendritic cells (imDCs).

View Article and Find Full Text PDF

Mutant ubiquitin UBB+1 is observed in a variety of aging-related neurodegenerative diseases and acts as a potent inhibitor of the ubiquitin proteasome system (UPS). In the present study, we investigated the relationship between impaired UPS (using ectopic expression of UBB+1) and mitochondrial dynamics in astrocytes, which are the most abundant glial cells in the central nervous system. Immunocytochemistry and fluorescence recovery after photobleaching revealed that ectopic expression of UBB+1 induced mitochondrial elongation.

View Article and Find Full Text PDF

Purpose: Asthma is a pulmonary chronic inflammatory disease characterized by airway obstruction and hyperresponsiveness. Pattern recognition receptors are known to play a key role in the development of allergic diseases as well as host defenses against microbial infection. Receptor interacting protein 2 (RIP2), a serine/threonine kinase, is an adaptor molecule of NOD1 and NOD2, and genetic variation in this receptor is known to be associated with the severity of allergic asthma in children.

View Article and Find Full Text PDF

Extrapulmonary deposition of macroaggregated albumin particles on lung perfusion scintigraphy occurs in the presence of right-to-left shunting, as demonstrated in this case of portosystemic shunting related to superior vena cava obstruction by germ cell tumor of the mediastinum. The case demonstrates the importance of examining tracer deposition within the entire field of view on (99m)Tc-macroaggregated albumin perfusion lung scintigraphy for extrapulmonary findings.

View Article and Find Full Text PDF

The value of (99m)Tc-labeled white blood cell scintigraphy for endovascular prosthetic infections is well known. In the unique case reported here, infection of the native aorta was detected in addition to an infected vascular prosthesis. The case demonstrates that (99m)Tc-labeled white blood cell scintigraphy can identify not only the more usual prosthetic stent/graft infection but also infection of the native aorta.

View Article and Find Full Text PDF

Gr-1(+)CD11b(+) cells can suppress innate and adaptive immunity, and the functional immunosuppressive characteristics of these cells can be modulated by the tumor microenvironment. Since Gr-1(+)CD11(+) cells are also involved in tumor-associated angiogenesis, we hypothesized that the angiogenic nature of Gr-1(+)CD11b(+) cells could be regulated by the tumor milieu. To address this hypothesis, we imitated a tumor microenvironment by exposing Gr-1(+)CD11b(+) cells isolated from spleen of 4T1 mammary carcinoma-bearing mice to tumor-conditioned medium.

View Article and Find Full Text PDF

During autophagy, a double membrane envelops cellular material for trafficking to the lysosome. Human beclin-1 and its yeast homologue, Atg6/Vps30, are scaffold proteins bound in a lipid kinase complex with multiple cellular functions, including autophagy. Several different Atg6 complexes exist, with an autophagy-specific form containing Atg14.

View Article and Find Full Text PDF

Background: The value of surgical resection in patients with hepatic metastases from melanoma is poorly documented in the literature. This study sought to determine the clinicopathologic and surgical factors predictive of outcome for melanoma patients who underwent resection of hepatic metastases.

Methods: Thirty-three patients who underwent liver resection for melanoma metastases were identified from the Melanoma Institute Australia research database.

View Article and Find Full Text PDF

Structured illumination microscopy (SIM) breaks the optical diffraction limit by illuminating a sample with a series of line-patterned light. Recently, in order to alleviate the requirement of precise knowledge of illumination patterns, structured illumination microscopy techniques using speckle patterns have been proposed. However, these methods require stringent assumptions of the speckle statistics: for example, speckle patterns should be nearly incoherent or their temporal average should be roughly homogeneous.

View Article and Find Full Text PDF

Transforming growth factor-β signaling is known to be a key signaling pathway in the induction of epithelial-mesenchymal transition. However, the mechanism of TGF-β signaling in the modulation of EMT remains unclear. In this study, we found that TGF-β treatment resulted in elongation of mitochondria accompanied by induction of N-cadherin, vimentin, and F-actin in retinal pigment epithelial cells.

View Article and Find Full Text PDF

Since most of the bioavailable drugs are impermeable through the blood-brain barrier (BBB), development of a rapid and reliable permeability assay system has been a challenge in drug discovery targeting central nervous system (CNS). Here, we designed a microfluidic device to monitor the drug permeability into the CNS. Human umbilical vein endothelial cells (HUVECs) were shortly (2 ~ 3 h) incubated with astrocyte-conditioned medium after being trapped on microholes in the microfluidic device and tested for chip-based permeability measurement of drugs.

View Article and Find Full Text PDF