Seung‐Jae Lee

Seoul National University

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Co-Authors

He-Jin Lee

Konkuk University

Eun-Jin Bae

Seoul National University

Eliezer Masliah

University of California, San Diego

Changyoun Kim

University of California, San Diego

Pyo‐Jam Park

Konkuk University

Byung Chul Jung

University of California, Berkeley

Jun Sung Lee

Gangnam Severance Hospital

Eun‐Kyung Kim

Dong-A University

Jin-Woo Hwang

Dankook University

Sang-Ho Moon

Sookmyung Women's University

Cooperative Institutions

Weatherford College

160

Seoul National University

147

Agruicultural Research Institute

111

Ames National Laboratory

111

Konkuk University

100

Boonton Public Schools

Yonsei University

Harvard University

Korea University

Pohang University of Science and Technology

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Enzymatic Synthesis of a Selective Inhibitor for α-Glucosidases: α-Acarviosinyl-(1→9)-3-α-d-glucopyranosylpropen

Journal of Agricultural and Food Chemistry (2008)

Young‐Su Lee Myoung-Hee Lee Hee‐Seob Lee Seung‐Jae Lee Young‐Wan Kim

Here, we describe the enzymatic synthesis of novel inhibitors using acarviosine-glucose as a donor and 3-α-d-glucopyranosylpropen (αGP) as an acceptor. Maltogenic amylase from Thermus sp. (ThMA) catalyzed the transglycosylation of the acarviosine moiety to αGP. The two major reaction products were isolated using chromatographies. Structural analyses revealed that acarviosine was transferred to either C-7 or C-9 of the αGP, which correspond to C-4 and C-6 of glucose. Both inhibited rat intestine α-glucosidase competitively but displayed a mixed-type inhibition mode against human pancreatic α-amylase. The α-acarviosinyl-(1→7)-3-α-d-glucopyranosylpropen showed weaker inhibition potency than acarbose against both α-glycosidases. In contrast, the α-acarviosinyl-(1→9)-3-α-d-glucopyranosylpropen exhibited a 3.0-fold improved inhibition potency against rat intestine α-glucosidase with 0.3-fold inhibition potency against human pancreatic α-amylase relative to acarbose. In conclusion, α-acarviosinyl-(1→9)-3-α-d-glucopyranosylpropen is a novel α-glucosidase-selective inhibitor with 10-fold enhanced selectivity toward α-glucosidase over α-amylase relative to acarbose, and it could be applied as a potent hypoglycemic agent.

Acarbose

Glucosidases

Alpha (finance)

Alpha-glucosidase

Alpha-amylase

10.1021/jf703655k

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Citations (12)

Topographical Propagation of α-synuclein Pathology in Parkinson's Disease: Phenomenology and Hypothetical Mechanism

Experimental Neurobiology (2009)

Minsuk Hyun Seung‐Jae Lee

Parkinson’s disease is an age-related, slowly progressing neurodegenerative disorder characterized by abnormal deposition of aggregated α-synuclein in neuronal cell bodies (Lewy bodies) and neurites (Lewy neurites), as well as in glia. Based on semiquantitative assessment of Lewy pathologies in autopsy samples, a staging system was proposed indicating a highly predictable sequence of pathological progression. This staging system implicates a propagation of α-synuclein aggregation throughout the brain with an ascending pattern from lower brain stem to neocortex. The underlying mechanism for the pathological propagation is unknown. However, the recent discoveries on the secretion of neuronal α-synuclein and subsequent uptake of the protein by neighboring cells propose an interneuronal transmission of α-synuclein aggregates as a novel mechanism for the spread of Lewy pathology in PD. Elucidation of this mechanism is likely to identify novel therapeutic strategies that halt the progression of PD.

10.5607/en.2009.18.1.19

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Citations (1)

The SH2-SH2-SH3 domain of phospholipase C-gamma1 directly binds to translational elongation factor-1alpha.

PubMed (1999)

Myung Jong Kim Fuchum Si Su Jeong Kim Seung Bum Hong Jong‐Ik Hwang

Phospholipase C-gamma1 (PLC-gamma1) is a lipase that hydrolyzes PIP2 to generate two second messengers, IP3 and DAG. By using the yeast two-hybrid system, we identified the translational elongation factor-1alpha (EF-1alpha) as a binding protein of PLC-gamma1 from the human B-lymphocyte library. Direct interaction between EF-1alpha and PLC-gamma1 was confirmed by the in vitro binding experiment using purified PLC-gamma1. Furthermore, from the in vitro binding experiment, we could demonstrate that the carboxyl terminal region of EF-1alpha is involved in the interaction with PLC-gamma1, and that both SH2 and SH3 domains of PLC-gamma1 are required for the interaction with EF-1alpha. In vivo interaction between EF-1alpha and PLC-gamma1 was confirmed by the immunoprecipitation experiment using anti-EF-1alpha antibody. The interaction between EF-1alpha and PLC-gamma1 was enhanced by EGF-treatment. Taken together, we suggest that EF-1alpha might play a role in PLC-gamma1-mediated signal transduction.

Two-hybrid screening

Immunoprecipitation

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Citations (13)

Purification and characterization of a novel peptide with inhibitory effects on colitis induced mice by dextran sulfate sodium from enzymatic hydrolysates of Crassostrea gigas

Fish & Shellfish Immunology (2012)

Jin-Woo Hwang Seung‐Jae Lee Yon-Suk Kim Eun‐Kyung Kim Chang‐Bum Ahn

Sodium dodecyl sulfate

10.1016/j.fsi.2012.08.017

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Citations (62)

A Case of Granulomatous Rosacea Localized on Both Eyelids

Linchuang pifuke zazhi (2010)

Young‐Jun Choi Seung‐Jae Lee Jae‐Hui Nam Heejung Kim Ga‐Young Lee

Granuloma formation

Source

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Inflammation drives synucleinopathy propagation

Research Square (Research Square) (2021)

Tae-Kyung Kim Eun-Jin Bae Byung Chul Jung Min-Sun Choi Soo-Jean Shin

Abstract The clinical progression of neurodegenerative diseases correlates with the spread of proteinopathy in the brain. Understanding of the mechanism of the proteinopathy spread is far from complete. Here, we propose that inflammation is fundamental to proteinopathy spread. A sequence variant of α-synuclein (V40G) was much less capable of fibril formation than wild-type α-synuclein (WT-syn) and, when mixed with WT-syn, interfered with its fibrillation. Yet when V40G was injected intracerebrally into mice, it induced aggregate spreading even more effectively than WT-syn. The aggregate spreading was preceded by sustained microgliosis and inflammatory responses, which were more robust with V40G than with WT-syn. Oral administration of an anti-inflammatory agent suppressed aggregate spreading, inflammation, and behavioral deficits in mice. Furthermore, exposure of cells to inflammatory cytokines increased the cell-to-cell propagation of α-synuclein. These results suggest that the inflammatory microenvironment is the major driver of the spread of synucleinopathy in the brain.

10.21203/rs.3.rs-774660/v1

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Impairment of microtubule‐dependent trafficking by overexpression of α‐synuclein

European Journal of Neuroscience (2006)

He‐Jin Lee Farnaz Khoshaghideh Stephen Lee Seung‐Jae Lee

Abstract Abnormal accumulation of α‐synuclein (α‐syn) has been linked to several neurological disorders, including Parkinson's disease (PD). However, the underlying mechanism by which α‐syn accumulation affects neuronal function and survival remains unknown. Here, we provide data suggesting a possible effect of aggregated α‐syn on the microtubule (MT) network. Consistent with the MT dysfunction, we also observed other degenerative changes, such as neuritic degeneration, trafficking defects, and Golgi fragmentation, which are common pathological features shared by many human neurodegenerative diseases. Neuritic degeneration and Golgi fragmentation were confirmed in primary cultures of dorsal root ganglia (DRG) neurons overexpressing α‐syn. This effect of α‐syn seems to have some selectivity to the MT system, as actin microfilaments and MT‐independent trafficking remain unaffected. Within the degenerating neurites, we found numerous spherical co‐aggregates of α‐syn and tubulins, from which actin was excluded. These studies suggest that the MT system is a potential target of α‐syn, and impairment of this system might have impacts on neuronal structure and function.

Neurite

Fragmentation

Axoplasmic transport

Degeneration (medical)

10.1111/j.1460-9568.2006.05210.x

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Citations (154)

Development of Three-Dimensional Alginate Encapsulated Chondrocyte Hybrid Scaffold Using Microstereolithography

Journal of Manufacturing Science and Engineering (2008)

Seung‐Jae Lee Jong‐Won Rhie Dong‐Woo Cho

Hydrogels are useful materials because of their chemical similarity to extracellular matrix and their ability to rapidly diffuse hydrophilic nutrients and metabolites. Using rapid prototyping methods, we fabricated freeform three-dimensional (3D) scaffolds with chondrocytes encapsulated in an alginate hydrogel. The 3D hybrid scaffold was developed as combination of two components, a trimethylene carbonate (TMC)/trimethylolpropane (TMP) framework and an alginate hydrogel within an encapsulation of chondrocytes. To develop 3D hybrid scaffolds, we employed a microstereolithography system. The biodegradable, photopolymerizable liquid prepolymer was prepared by the polymerization of TMC with TMP and subsequently end capped with an acrylate group. The meshed framework of scaffolds withstood mechanical loading effectively. The line depth and linewidth could be controlled by varying laser power, scan path, and scan speed. Results of cell culture indicate that the biomimetic nature of these encapsulated chondrocyte scaffolds effectively retain the phenotypic function of chondrocytes within the scaffold structure. The proposed 3D hybrid scaffolds can be used for cartilage regeneration.

Stereolithography

Polycaprolactone

Cell encapsulation

10.1115/1.2896114

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Citations (16)

Single-Molecule FRET Analysis of Replicative Helicases

Methods in molecular biology (2018)

Seung‐Jae Lee Salman Syed Taekjip Ha

Single-molecule FRET

Biomolecule

10.1007/978-1-4939-8556-2_12

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Citations (5)

Lipid Peroxidation Product 4-Hydroxy-2-Nonenal Promotes Seeding-Capable Oligomer Formation and Cell-to-Cell Transfer of α-Synuclein

Antioxidants and Redox Signaling (2012)

Eun-Jin Bae Dong Hwan Ho Eunbi Park Jin Woo Jung Kyungcho Cho

Abnormal accumulation of α-synuclein aggregates is one of the key pathological features of many neurodegenerative movement disorders and dementias. These pathological aggregates propagate into larger brain regions as the disease progresses, with the associated clinical symptoms becoming increasingly severe and complex. However, the factors that induce α-synuclein aggregation and spreading of the aggregates remain elusive. Herein, we have evaluated the effects of the major lipid peroxidation byproduct 4-hydroxy-2-nonenal (HNE) on α-synuclein oligomerization and cell-to-cell transmission of this protein.

Oligomer

4-Hydroxynonenal

Amyloid (mycology)

10.1089/ars.2011.4429

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Citations (111)