Chulhee Choi

Mesenchymal stem cells (MSCs) are one of the most easily accessible stem cells that can be obtained from various human tissues. They have raised considerable interests for their potential applications in tissue repair, anti-cancer therapy, and inflammation suppression. Stem cell-based therapy was first used to treat muscular dystrophies and has been studied intensively for its efficacy in various disease models, including myocardial infarction, kidney injuries, liver injuries, and cancers. In th

Oxidative stresses caused by reactive oxygen species (ROS) can induce rapid depolarization of inner mitochondrial membrane potential and subsequent impairment of oxidative phosphorylation. Damaged mitochondria produce more ROS, especially the superoxide anion (O(2)(-)) and hydrogen peroxide (H(2)O(2)), which potentiate mitochondria-driven ROS propagation, so-called ROS-induced ROS release (RIRR), via activation of an inter-mitochondria signaling network. Therefore, loss of function in only a fra

Abstract Fas ligand (FasL) and Fas are mediators of apoptosis, which are implicated in the peripheral deletion of autoimmune cells, activation-induced T cell death, and cytotoxicity mediated by CD8+ T cells. Fas is also believed to be involved in several central nervous system diseases, but until now, the effector cells expressing FasL in the brain have not been identified. We investigated the expression levels of Fas and FasL with the stimulation of cytokines and the possible effector cells tar

Oxidative stress is deeply involved in various brain diseases, including neurodegenerative diseases, stroke, and ischemia/reperfusion injury. Mitochondria are thought to be the target and source of oxidative stress. We investigated the role of mitochondria in oxidative stress-induced necrotic neuronal cell death in a neuroblastoma cell line and a mouse model of middle cerebral artery occlusion. The exogenous administration of hydrogen peroxide was used to study the role of oxidative stress on ne

Among the tumor necrosis factor (TNF) family of cytokines, FasL and TNF-related apoptosis-inducing ligand (TRAIL) are known to induce cell death via caspase activation. Recently, other biological functions of these death ligands have been postulated in vitro and in vivo. It was previously shown that Fas ligation induces chemokine expression in human glioma cells. In this study, we investigated whether the TRAIL-DR5 system transduces signals similar to those induced by other TNF family ligands an

Delivering therapeutics to the central nervous system (CNS) is difficult because of the blood-brain barrier (BBB). Therapeutic delivery across the tight junctions of the BBB can be achieved through various endogenous transportation mechanisms. Receptor-mediated transcytosis (RMT) is one of the most widely investigated and used methods. Drugs can hijack RMT by expressing specific ligands that bind to receptors mediating transcytosis, such as the transferrin receptor (TfR), low-density lipoprotein

Fas transduces not only apoptotic signals through various pathways but also angiogenic and proinflammatory responses in vivo. Human glioma cells express Fas although sensitivity to Fas-mediated cell death is variable, suggesting that Fas may have functions other than apoptosis in these cells. In this study, we addressed alternative functions of Fas expressed on human gliomas by Fas ligation in three human glioma cell lines, CRT-MG, U373-MG, and U87-MG, and the in vivo expression of Fas and chemo

Loss of contractility and acquisition of an epithelial phenotype of vascular smooth muscle cells (VSMCs) are key events in proliferative vascular pathologies such as atherosclerosis and post-angioplastic restenosis. There is no proper cell culture system allowing differentiation of VSMCs so that it is difficult to delineate the molecular mechanism responsible for proliferative vasculopathy. We investigated whether a micropatterned substrate could restore the contractile phenotype of VSMCs in vit

The extracellular vesicles (EVs) research area has grown rapidly because of their pivotal roles in intercellular communications and maintaining homeostasis of individual organism. As a subtype of EVs, exosomes are made via unique biogenesis pathway and exhibit disparate functional and phenotypic characteristics. Functionally, exosomes transfer biological messages from donor cell to recipient cell, which makes exosomes as a novel therapeutic platform delivering therapeutic materials to the target

HCV infection enhances TNF-α-induced cell death by suppressing NF-κB activation through the action of core, NS4B, and NS5B. This mechanism may contribute to immune-mediated liver injury in HCV infection.

The analysis of multiple inflammatory mediators revealed marginal differences in their CSF and serum concentrations for the differential diagnosis of AD and PD. These results provide evidence that immunological responses are not major contributors to the pathogenesis of AD and PD.