Chi Hern Lee
Hallym University
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Featured researches published by Chi Hern Lee.
Free Radical Biology and Medicine | 2013
Mi Jin Kim; Dae Won Kim; Jung Hwan Park; Sang Jin Kim; Chi Hern Lee; Ji In Yong; Eun Ji Ryu; Su Bin Cho; Hyeon Ji Yeo; Jiye Hyeon; Sung-Woo Cho; Duk-Soo Kim; Ora Son; Jinseu Park; Kyu Hyung Han; Yoon Shin Cho; Won Sik Eum; Soo Young Choi
Sirtuin 2 (SIRT2), a member of the sirtuin family of proteins, plays an important role in cell survival. However, the biological function of SIRT2 protein is unclear with respect to inflammation and oxidative stress. In this study, we examined the protective effects of SIRT2 on inflammation and oxidative stress-induced cell damage using a cell permeative PEP-1-SIRT2 protein. Purified PEP-1-SIRT2 was transduced into RAW 264.7 cells in a time- and dose-dependent manner and protected against lipopolysaccharide- and hydrogen peroxide (H₂O₂)-induced cell death and cytotoxicity. Also, transduced PEP-1-SIRT2 significantly inhibited the expression of cytokines as well as the activation of NF-κB and mitogen-activated protein kinases (MAPKs). In addition, PEP-1-SIRT2 decreased cellular levels of reactive oxygen species (ROS) and of cleaved caspase-3, whereas it elevated the expression of antioxidant enzymes such as MnSOD, catalase, and glutathione peroxidase. Furthermore, topical application of PEP-1-SIRT2 to 12-O-tetradecanoylphorbol 13-acetate-treated mouse ears markedly inhibited expression levels of COX-2 and proinflammatory cytokines as well as the activation of NF-κB and MAPKs. These results demonstrate that PEP-1-SIRT2 inhibits inflammation and oxidative stress by reducing the levels of expression of cytokines and ROS, suggesting that PEP-1-SIRT2 may be a potential therapeutic agent for various disorders related to ROS, including skin inflammation.
Free Radical Biology and Medicine | 2014
Young Nam Kim; Hyo Young Jung; Won Sik Eum; Dae Won Kim; Min Jea Shin; Eun Hee Ahn; Sang Jin Kim; Chi Hern Lee; Ji In Yong; Eun Ji Ryu; Jinseu Park; Jung Hoon Choi; In Koo Hwang; Soo Young Choi
Human carbonyl reductase 1 (CBR1) is a member of the NADPH-dependent short-chain dehydrogenase/reductase superfamily that is known to play an important role in neuronal cell survival via its antioxidant function. Oxidative stress is one of the major causes of degenerative disorders including ischemia. However, the role CBR1 plays with regard to ischemic injury is as yet poorly understood. Protein transduction domains such as PEP-1 are well known and now commonly used to deliver therapeutic proteins into cells. In this study, we prepared PEP-1-CBR1 protein and examined whether it protects against oxidative-stress-induced neuronal cell damage. PEP-1-CBR1 protein was efficiently transduced into hippocampal neuronal HT-22 cells and protected against hydrogen peroxide (H2O2)-induced neuronal cell death. Transduced PEP-1-CBR1 protein drastically inhibited H2O2-induced reactive oxygen species production, the oxidation of intracellular macromolecules, and the activation of mitogen-activated protein kinases, as well as cellular apoptosis. Furthermore, we demonstrated that transduced PEP-1-CBR1 protein markedly protected against neuronal cell death in the CA1 region of the hippocampus resulting from ischemic injury in an animal model. In addition, PEP-1-CBR1 protein drastically reduced activation of glial cells and lipid peroxidation in an animal model. These results indicate that PEP-1-CBR1 protein significantly protects against oxidative-stress-induced neuronal cell death in vitro and in vivo. Therefore, we suggest that PEP-1-CBR1 protein may be a therapeutic agent for the treatment of ischemic injuries as well as oxidative-stress-induced cell damage and death.
Biomaterials | 2015
Mi Jin Kim; Meeyoung Park; Dae-Won Kim; Min Jea Shin; Ora Son; Hyo Sang Jo; Hyeon Ji Yeo; Su Bin Cho; Jung Hwan Park; Chi Hern Lee; Duk Soo Kim; Oh Shin Kwon; Joon Kim; Kyu Hyung Han; Jinseu Park; Won Sik Eum; Soo Young Choi
Parkinsons disease (PD) is an oxidative stress-mediated neurodegenerative disorder caused by selective dopaminergic neuronal death in the midbrain substantia nigra. Paraoxonase 1 (PON1) is a potent inhibitor of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) against oxidation by destroying biologically active phospholipids with potential protective effects against oxidative stress-induced inflammatory disorders. In a previous study, we constructed protein transduction domain (PTD) fusion PEP-1-PON1 protein to transduce PON1 into cells and tissue. In this study, we examined the role of transduced PEP-1-PON1 protein in repressing oxidative stress-mediated inflammatory response in microglial BV2 cells after exposure to lipopolysaccharide (LPS). Moreover, we identified the functions of transduced PEP-1-PON1 proteins which include, mitigating mitochondrial damage, decreasing reactive oxidative species (ROS) production, matrix metalloproteinase-9 (MMP-9) expression and protecting against 1-methyl-4-phenylpyridinium (MPP(+))-induced neurotoxicity in SH-SY5Y cells. Furthermore, transduced PEP-1-PON1 protein reduced MMP-9 expression and protected against dopaminergic neuronal cell death in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice model. Taken together, these results suggest a promising therapeutic application of PEP-1-PON1 proteins against PD and other inflammation and oxidative stress-related neuronal diseases.
Molecular Immunology | 2015
Hye Ri Kim; Dae-Won Kim; Hyo Sang Jo; Su Bin Cho; Jung Hwan Park; Chi Hern Lee; Yeon Joo Choi; Eun Ji Yeo; Sung Yeon Park; Seung Tae Kim; Yeon Hee Yu; Duk-Soo Kim; Hyun Ah Kim; Sung-Woo Cho; Kyu Hyung Han; Jinseu Park; Won Sik Eum; Soo Young Choi
Reactive oxygen species (ROS) accumulation induces oxidative stress and cell damage, which then activates several signaling pathways and triggers inflammatory response. Biliverdin is a natural product of heme metabolism which is converted to bilirubin by the enzyme biliverdin reductase A (BLVRA) which also plays a role in antioxidant activity via the ROS scavenging activity of bilirubin. In this study, we examined the anti-inflammatory and anti-apoptotic effects of Tat-BLVRA protein on lipopolysaccharide (LPS)-induced inflammation in Raw 264.7 macrophage cells. Transduction of Tat-BLVRA protein into Raw 264.7 cells and mice ear tissue was tested by Western blot analysis and immunohistochemical analysis. Tat-BLVRA protein was effective in inhibiting mitogen activated protein kinases (MAPKs), Akt and NF-κB activation, intracellular ROS production and DNA fragmentation. Also, Tat-BLVRA protein significantly inhibited the expression of cytokines, COX-2, and iNOS. In a 12-O-tetradecanoylphobol 13-acetate (TPA)-induced mouse model, mice ears treated with Tat-BLVRA protein showed decreased ear thickness and weight, as well as inhibited MAPKs activation and cytokine expression. Thus we suggested that Tat-BLVRA protein may provide an effective therapeutic agent for inflammatory skin diseases.
Journal of Biochemistry and Molecular Biology | 2015
Dae Won Kim; Sung Ho Lee; Min Jea Shin; Kibom Kim; Sae Kwang Ku; Jong Kyu Youn; Su Bin Cho; Jung Hwan Park; Chi Hern Lee; Ora Son; Eun Jeong Sohn; Sung-Woo Cho; Jong Hoon Park; Hyun Ah Kim; Kyu Hyung Han; Jinseu Park; Won Sik Eum; Soo Young Choi
FK506 binding protein 12 (FK506BP) is a small peptide with a single FK506BP domain that is involved in suppression of immune response and reactive oxygen species. FK506BP has emerged as a potential drug target for several inflammatory diseases. Here, we examined the protective effects of directly applied cell permeable FK506BP (PEP-1-FK506BP) on corneal alkali burn injury (CAI). In the cornea, there was a significant decrease in the number of cells expressing pro-inflammation, apoptotic, and angiogenic factors such as TNF-α, COX-2, and VEGF. Both corneal opacity and corneal neovascularization (CNV) were significantly decreased in the PEP-1-FK506BP treated group. Our results showed that PEP-1-FK506BP can significantly inhibit alkali burn-induced corneal inflammation in rats, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors and inflammatory cytokines. These results suggest that PEP-1-FK506BP may be a potential therapeutic agent for CAI. [BMB Reports 2015; 48(11): 618-623]
Journal of Biochemistry and Molecular Biology | 2016
Hyo Sang Jo; Hyeon Ji Yeo; Hyun Ju Cha; Sang Jin Kim; Su Bin Cho; Jung Hwan Park; Chi Hern Lee; Eun Ji Yeo; Yeon Joo Choi; Won Sik Eum; Soo Young Choi
Loss of pancreatic β-cells by oxidative stress or cytokines is associated with diabetes mellitus (DM). DJ-1 is known to as a multifunctional protein, which plays an important role in cell survival. We prepared cell permeable wild type (WT) and mutant type (M26I) Tat-DJ-1 proteins to investigate the effects of DJ-1 against combined cytokines (IL-1β, IFN-γ and TNF-α)-induced RINm5F cell death. Both Tat-DJ-1 proteins were transduced into RINm5F cells. WT Tat-DJ-1 proteins significantly protected against cell death from cytokines by reducing intracellular toxicities. Also, WT Tat-DJ-1 proteins markedly regulated cytokines-induced pro- and anti-apoptosis proteins. However, M26I Tat-DJ-1 protein showed relatively low protective effects, as compared to WT Tat-DJ-1 protein. Our experiments demonstrated that WT Tat-DJ-1 protein protects against cytokine-induced RINm5F cell death by suppressing intracellular toxicities and regulating apoptosisrelated protein expression. Thus, WT Tat-DJ-1 protein could potentially serve as a therapeutic agent for DM and cytokine related diseases. [BMB Reports 2016; 49(5): 297-302]
Biotechnology Letters | 2017
Hyo Sang Jo; Eun Ji Yeo; Min Jea Shin; Yeon Joo Choi; Hyeon Ji Yeo; Su Bin Cho; Jung Hwan Park; Chi Hern Lee; Won Sik Eum; Soo Young Choi
ObjectivesTo identify the protective effect of DJ-1 protein against oxidative stress-induced HepG2 cell death, we used cell-permeable wild type (WT) and a mutant (C106A Tat-DJ-1) protein.ResultsBy using western blotting and fluorescence microscopy, we observed WT and C106A Tat-DJ-1 proteins were efficiently transduced into HepG2 cells. Transduced WT Tat-DJ-1 proteins increased cell survival and protected against DNA fragmentation and intracellular ROS generation levels in H2O2-exposed HepG2 cells. At the same time, transduced WT Tat-DJ-1 protein significantly inhibited NF-κB and MAPK (JNK and p38) activation as well as regulated the Bcl-2 and Bax expression levels. However, C106A Tat-DJ-1 protein did not show any protective effect against cell death responses in H2O2-exposed HepG2 cells.ConclusionsOxidative stress-induced HepG2 cell death was significantly reduced by transduced WT Tat-DJ-1 protein, not by C106A Tat-DJ-1 protein. Thus, transduction of WT Tat-DJ-1 protein could be a novel strategy for promoting cell survival in situations of oxidative stress-induced HepG2 cell death.
Molecular Brain | 2017
Hyo Sang Jo; Dae Won Kim; Min Jea Shin; Su Bin Cho; Jung Hwan Park; Chi Hern Lee; Eun Ji Yeo; Yeon Joo Choi; Hyeon Ji Yeo; Eun Jeong Sohn; Ora Son; Sung-Woo Cho; Duk-Soo Kim; Yeon Hee Yu; Keun Wook Lee; Jinseu Park; Won Sik Eum; Soo Young Choi
Oxidative stress plays an important role in the progression of various neuronal diseases including ischemia. Heat shock protein 22 (HSP22) is known to protect cells against oxidative stress. However, the protective effects and mechanisms of HSP22 in hippocampal neuronal cells under oxidative stress remain unknown. In this study, we determined whether HSP22 protects against hydrogen peroxide (H2O2)-induced oxidative stress in HT-22 using Tat-HSP22 fusion protein. We found that Tat-HSP22 transduced into HT-22 cells and that H2O2-induced cell death, oxidative stress, and DNA damage were significantly reduced by Tat-HSP22. In addition, Tat-HSP22 markedly inhibited H2O2-induced mitochondrial membrane potential, cytochrome c release, cleaved caspase-3, and Bax expression levels, while Bcl-2 expression levels were increased in HT-22 cells. Further, we showed that Tat-HSP22 transduced into animal brain and inhibited cleaved-caspase-3 expression levels as well as significantly inhibited hippocampal neuronal cell death in the CA1 region of animals in the ischemic animal model. In the present study, we demonstrated that transduced Tat-HSP22 attenuates oxidative stress-induced hippocampal neuronal cell death through the mitochondrial signaling pathway and plays a crucial role in inhibiting neuronal cell death, suggesting that Tat-HSP22 protein may be used to prevent oxidative stress-related brain diseases including ischemia.
Medicinal Chemistry Research | 2016
Hyo Sang Jo; Hyun Ju Cha; Sang Jin Kim; Hyeon Ji Yeo; Su Bin Cho; Jung Hwan Park; Chi Hern Lee; Eun Ji Yeo; Yeon Joo Choi; Won Sik Eum; Soo Young Choi
Oxidative stress is highly involved in the development of diabetes mellitus by destruction of pancreatic β-cells. DJ-1 is an antioxidant protein and DJ-1 expression levels are known to be reduced in diabetes mellitus. Thus, we examined the effects of DJ-1 protein against oxidative stress-induced pancreatic β-cell (RINm5F) death using cell permeable wild-type and mutant-type (C106A) Tat-DJ-1 proteins, which both efficiently transduced into RINm5F cells. Intracellular stability of wild-type Tat-DJ-1 persisted two times longer than C106A Tat-DJ-1. Wild-type Tat-DJ-1 protein markedly protected cells from hydrogen peroxide-induced toxicities such as cell death, reactive oxygen species generation, and DNA fragmentation. Further, wild-type Tat-DJ-1 protein significantly inhibited hydrogen peroxide-induced activation of mitogen-activated protein kinases and NF-κB signaling. On the other hand, C106A Tat-DJ-1 protein did not show the same protective effects. These results indicate that wild-type Tat-DJ-1 inhibits oxidative stress-induced cellular toxicity and activation of mitogen-activated protein kinases and NF-κB signals in RINm5F cells. These results suggest that wild-type Tat-DJ-1 protein may be a potential therapeutic agent against diabetes mellitus or toward the prevention of pancreatic β-cell destruction.
Journal of Biochemistry and Molecular Biology | 2016
Hyo Sang Jo; Duk-Soo Kim; Eun Hee Ahn; Dae-Won Kim; Min Jea Shin; Su Bin Cho; Jung Hwan Park; Chi Hern Lee; Eun Ji Yeo; Yeon Joo Choi; Hyeon Ji Yeo; Christine Seok Young Chung; Sung-Woo Cho; Kyu Hyung Han; Jinseu Park; Won Sik Eum; Soo Young Choi
Oxidative stress is closely associated with various diseases and is considered to be a major factor in ischemia. NAD(P)H: quinone oxidoreductase 1 (NQO1) protein is a known antioxidant protein that plays a protective role in various cells against oxidative stress. We therefore investigated the effects of cell permeable Tat-NQO1 protein on hippocampal HT-22 cells, and in an animal ischemia model. The Tat-NQO1 protein transduced into HT-22 cells, and significantly inhibited against hydrogen peroxide (H2O2)-induced cell death and cellular toxicities. Tat-NQO1 protein inhibited the Akt and mitogen activated protein kinases (MAPK) activation as well as caspase-3 expression levels, in H2O2 exposed HT-22 cells. Moreover, Tat-NQO1 protein transduced into the CA1 region of the hippocampus of the animal brain and drastically protected against ischemic injury. Our results indicate that Tat-NQO1 protein exerts protection against neuronal cell death induced by oxidative stress, suggesting that Tat-NQO1 protein may potentially provide a therapeutic agent for neuronal diseases.