Hyun Kyu Lee

BACKGROUND: Zinc, an essential trace element, inhibits osteoclast differentiation in vitro and in vivo. The molecular mechanism for the inhibitory effect of zinc, however, is poorly understood. The purpose of this study was to investigate the effect of zinc and determine its molecular mechanism on receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis in mouse bone marrow-derived monocyte cells (BMMs) and RAW264.7 cells. RESULTS: In BMMs, zinc treatment during osteoclast different

INTRODUCTION: Microparticles (MPs) derived from kidney-derived mesenchymal stem cells (KMSCs) have recently been reported to ameliorate rarefaction of peritubular capillaries (PTC) in ischemic kidneys via delivery of proangiogenic effectors. This study aimed to investigate whether KMSC-derived MPs show anti-fibrotic effects by ameliorating endothelial-to-mesenchymal transition (EndoMT) in human umbilical vein endothelial cells (HUVEC) in vitro and by preserving PTC in kidneys with unilateral ure

Although targeting radioresistant tumor cells is essential for enhancing the efficacy of radiotherapy, the signals activated in resistant tumors are still unclear. This study shows that ERp57 contributes to radioresistance of laryngeal cancer by activating STAT3. Increased ERp57 was associated with the radioresistant phenotype of laryngeal cancer cells. Interestingly, increased interaction between ERp57 and STAT3 was observed in radioresistant cells, compared to the control cells. This physical

BACKGROUND AND PURPOSE: Activation of hepatic stellate cells (HSCs) is a crucial step in the pathogenesis of hepatic fibrosis. Histone deacetylase (HDAC) is an attractive target in liver fibrosis because it plays a key role in gene expression and cell differentiation. We have developed a HDAC inhibitor, N-hydroxy-7-(2-naphthylthio)heptanomide (HNHA), and investigated the anti-fibrotic activity of HNHA in vitro and in vivo. EXPERIMENTAL APPROACH: We investigated the anti-fibrotic effect of HNHA o

Abstract Purpose: Cancer cells grow in an unfavorable metabolic milieu in the tumor microenvironment and are constantly exposed to metabolic stress such as chronic nutrient depletion. Cancer stem-like cells (CSC) are intrinsically resistant to metabolic stress, thereby surviving nutrient insufficiency and driving more malignant tumor progression. In this study, we aimed to demonstrate the potential mechanisms by which CSCs avoid Ca2+-dependent apoptosis during glucose deprivation. Experimental D

Exposure of the skin to ultraviolet radiation can cause skin damage with various pathological changes including inflammation. In the present study, we identified the skin-protective activity of 1,2,3,4,6-penta-O-galloyl-β-D-glucose (pentagalloyl glucose, PGG) in ultraviolet B (UVB) radiation-induced human dermal fibroblasts and mouse skin. PGG exhibited antioxidant activity with regard to intracellular reactive oxygen species (ROS) generation as well as ROS and reactive nitrogen species (RNS) sc

DKK-1 might be a key regulator in HCC progression and a potential therapeutic target in HCC. Serum DKK-1 could complement the diagnostic accuracy of AFP and DCP.

// Hyun Gyu Lee 1 , Hyemi Kim 1, 2 , Taekwon Son 3 , Youngtae Jeong 4 , Seung Up Kim 5 , Seung Myung Dong 6 , Young Nyun Park 2, 7 , Jong Doo Lee 8 , Jae Myun Lee 1, 2 , Jeon Han Park 1 1 Department of Microbiology and Immunology, Institute for Immunology and Immunological Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea 2 Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Republic of Korea 3 Research Institute of Pharmaceutic

Tumor angiogenesis is essential for invasive tumor growth and metastasis. Dickkopf-1 (DKK-1), an antagonist of Wnt signaling, participates in tumor development and progression. We evaluated whether DKK-1 stimulation induces angiogenesis and the endothelial-mesenchymal transition (EnMT). Human umbilical vein endothelial cells (HUVECs) were stimulated with recombinant DKK-1 (rDDK-1) or conditioned medium from a culture of DKK-1-transfected 293 cells. Following stimulation, the expression levels of

// Hyun Gyu Lee 1, * , Hyemi Kim 1, 2, * , Eun Jung Kim 3 , Pil-Gu Park 1 , Seung Myung Dong 4 , Tae Hyun Choi 3 , Hyunki Kim 5 , Curtis R. Chong 6, 7 , Jun O. Liu 8, 9 , Jianmeng Chen 9 , Richard F. Ambinder 9 , S. Diane Hayward 9 , Jeon Han Park 1 , Jae Myun Lee 1, 2 1 Department of Microbiology and Immunology, Yonsei University College of Medicine, Seoul, Republic of Korea 2 Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Republic of Korea 3 Rad

Lysozyme protects us from the ever-present danger of bacterial infection and binds to bacterial lipopolysaccharide (LPS) with high affinity. Beyond its role in the activation of protein C, the endothelial cell protein C receptor (EPCR) plays an important role in the cytoprotective pathway. EPCR can be shed from the cell surface, which is mediated by tumor necrosis factor-α converting enzyme (TACE). However, little is known about the effects of lysozyme on EPCR shedding. We investigated this issu

The naive T-cell pool in peripheral lymphoid tissues is fairly stable in terms of number, diversity and functional capabilities in spite of the absence of prominent stimuli. This stability is attributed to continuous tuning of the composition of the T-cell pool by various homeostatic signals. Despite extensive research into the link between signal transducer and activator of transcription 3 (Stat3) and T-cell survival, little is known about how Stat3 regulates homeostasis by maintaining the requ

Interferon regulatory factor-5 (IRF-5), a member of the mammalian IRF transcription factor family, is regulated by p53, type I interferon and virus infection. IRF-5 participates in virus-induced TLR-mediated innate immune responses and may play a role as a tumor suppressor. It was suppressed in various EBV-infected transformed cells, thus it is valuable to identify the suppression mechanism. We focused on a promoter CpG islands methylation, a kind of epigenetic regulation in EBV-associated Burki