Publications by authors named "Hyunhee Shin"

Peroxidated lipids accumulate in the presence of reactive oxygen species and are linked to neurodegenerative diseases. Here we find that neuronal ablation of ARF1, a small GTPase important for lipid homeostasis, promoted accumulation of peroxidated lipids, lipid droplets and ATP in the mouse brain and led to neuroinflammation, demyelination and neurodegeneration, mainly in the spinal cord and hindbrain. Ablation of ARF1 in cultured primary neurons led to an increase in peroxidated lipids in co-cultured microglia, activation of the microglial NLRP3 inflammasome and release of inflammatory cytokines in an Apolipoprotein E-dependent manner.

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Purpose: Recent studies revealed that metabolic stress influences the outcomes of breast cancer treatment. We sought to evaluate the prognostic effect of type 2 diabetes and find the molecular mechanism of relapses in postoperative HER-2+ breast cancer patients treated with HER-2 targeted therapy.

Materials And Methods: We evaluated 190 HER-2+ breast cancer patients (pT1-4N0-2M0) who were treated with surgical resection and trastuzumab (HER-2 targeted therapy) between 2006 and 2015.

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Extracellular matrix dysregulation is associated with chronic liver disease. CollagenVI-alpha3 chain (COL6A3) is a biomarker for hepatic fibrosis and poor prognosis of hepatocellular carcinoma (HCC), but its function in liver pathology remains unknown. High levels of COL6A3 and its cleaved product, endotrophin (ETP) in tumor-neighboring regions are strongly associated with poor prognosis in HCC patients.

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Purpose: Protein cages are promising nanoplatform candidates for efficient delivery systems due to their homogenous size and structure with high biocompatibility and biodegradability. In this study, we investigate the potential of lumazine synthase protein cage as an antigen delivery system to dendritic cells (DCs), which induce antigen-specific T cell proliferation.

Materials And Methods: Ovalbumin (OVA) peptides OT-1 (SIINFEKL) and OT-2 (ISQAVHAAHAEINEAGR) were genetically inserted to lumazine synthase and each protein cage was over-expressed in Escherichia coli as a soluble protein.

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Genetic and chemical engineering approaches are used to employ P22 viral capsids as nanoplatforms for developing an efficient delivery vehicle. Catechol ligands are chemically attached to the interior surface of P22 viral capsid for subsequent encapsulation of an anticancer drug, bortezomib (BTZ), through boronic acid-diol complexation. For targeted delivery, hepatocellular carcinoma (HCC)-targeting peptide (SP94, SFSIIHTPILPL) is synthesized and chemically conjugated to the exterior surface of the P22 viral capsid nanocomposites.

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Unlabelled: We utilized ferritin protein cage nanoparticles (FPCN) as antigen delivery nanoplatforms for DC-based vaccine development and investigated DC-mediated antigen-specific immune responses. Antigenic peptides, OT-1 (SIINFEKL) or OT-2 (ISQAVHAAHAEINEAGR) which are derived from ovalbumin, were genetically introduced either onto the exterior surface or into the interior cavity of FPCN. FPCN carrying antigenic peptides (OT-1-FPCN and OT-2-FPCN) were effectively delivered to DCs and processed within endosomes.

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A capsid-forming enzyme, lumazine synthase isolated from hyperthermophile Aquifex aeolicus (AaLS), is prepared and utilized as a template for constructing nanobuilding blocks to fabricate uniform layer-by-layer (LbL) assemblies. Two functionally complementary AaLS protein cage nanoparticles (PCNs) are generated either by genetically introducing His-tags on the surface of wild-type AaLS PCNs or by chemically attaching metal chelates (Ni-NTA moiety) to the surface of cysteine-bearing AaLS PCNs individually. The multivalent displays of His-tags (AaLS-His PCN) and Ni-NTA ligands (AaLS-NTA-Ni PCN) on the surface of each complementary AaLS PCN are successfully demonstrated by mass spectrometric and surface plasmon resonance analyses.

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P22 viral capsids and ferritin protein cages are utilized as templating macromolecules to conjugate Gd(III)-chelating agent complexes, and we systematically investigates the effects of the macromolecules' size and the conjugation positions of Gd(III)-chelating agents on the magnetic resonance (MR) relaxivities and the resulting image contrasts. The relaxivity values of the Gd(III)-chelating agent-conjugated P22 viral capsids (outer diameter: 64 nm) are dramatically increased as compared to both free Gd(III)-chelating agents and Gd(III)-chelating agent-conjugated ferritins (outer diameter: 12 nm), suggesting that the large sized P22 viral capsids exhibit a much slower tumbling rate, which results in a faster T1 relaxation rate. Gd(III)-chelating agents are attached to either the interior or exterior surface of P22 viral capsids and the conjugation positions of Gd(III)-chelating agents, however, do not have a significant effect on the relaxivity values of the macromolecular conjugates.

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Protein cages are spherical hollow supramolecules that are attractive nanoscale platforms for constructing cargo delivery vehicles. Using ferritin isolated from the hyperthermophilic archaeon Pyrococcus furiosus (Pf_Fn), we developed a multifunctional protein cage-based delivery nanoplatform that can hold cargo molecules securely, deliver them to the targeted sites, and release them to the targeted cells. The release is triggered by cleavage induced by the protease, thrombin.

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We genetically introduced the Fc-binding peptide (FcBP) into the loop of a self-assembled protein cage, ferritin, constituting four-fold symmetry at the surface to use it as a modular delivery nanoplatform. FcBP-presenting ferritin (FcBP-ferritin) formed very stable non-covalent complexes with both human and rabbit IgGs through the simple molecular recognition between the Fc region of the antibodies and the Fc-binding peptide clusters inserted onto the surface of FcBP-ferritin. This approach realized orientation-controlled display of antibodies on the surfaces of the protein cages simply by mixing without any complicated chemical conjugation.

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Peritoneal injection of lipopolysaccharide (LPS) increased the influx of polymorphonuclear leukocytes and macrophages into the peritoneal cavity (PEC), with significantly higher cell numbers in the 4-1BB-deficient (KO) mice than in wild-type (WT) mice. The peritoneal macrophages of KO mice contained less IL-10 transcripts and protein than those of WT after LPS treatment, and immobilization of 4-1BB-Fc increased the level of IL-10. Injection of IL-10 resulted in lower cell numbers into the PEC of KO mice, suggesting that lower level of IL-10 is responsible for stimulated cell influx in KO mice due to lack of 4-1BB and 4-1BBL interaction.

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Objectives: We compared osteoclast (OC) formation in bone marrow-derived macrophages (BMM) from C57BL/6 (B/6) and BALB/c (B/c) mice. After stimulation of receptor activator of nuclear factor-kappaB ligand (RANKL), enhanced OC formation and higher level of macrophage inflammatory protein-1alpha (MIP-1alpha) were observed in the BMM from B/c mice. In this study, we determined whether MIP-1alpha is responsible for stimulated OC formation in the BMM.

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Unlabelled: Enhanced osteoclastogenesis was observed in bone marrow-derived macrophage cells from 4-1BB-deficient mice than in those from wildtype mice. 4-1BB and 4-1BB ligand interaction may play a role at a certain stage of osteoclast formation through increased level of IL-10, a negative regulator of osteoclastogenesis.

Introduction: 4-1BB is an inducible T-cell costimulatory molecule and a member of the TNF receptor family.

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Soluble glucocorticoid-induced tumor necrosis factor receptor (sGITR) is a potent stimulator of osteoclastogenesis. The mechanism by which it induces osteoclastogenesis was studied by culturing bone-marrow-derived macrophages (BMM) with conditioned medium from mouse bone marrow stromal cells. GITR and GITR ligand (GITRL) were expressed on the surface of bone marrow stromal cells, and sGITR-induced osteoclastogenesis was inhibited by anti-GITRL Ab, indicating that stimulatory effect of osteoclastogenesis by sGITR involved signaling via GITRL.

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We tested whether any intracellular signals are transmitted through 4-1BB/CD137 ligand (4-1BBL), using a 4-1BB-Fc fusion protein and 4-1BB-deficient mice. Immobilized 4-1BB-Fc fusion protein strongly inhibited osteoclastogenesis induced by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-kappaB ligand (RANKL) derived from bone marrow macrophages (BMM). Incubation of BMM with M-CSF increased 4-1BBL mRNA and surface expression of 4-1BBL protein.

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We show that sulforaphane inhibits osteoclastogenesis in the presence of macrophage colony-stimulating factor (M-CSF) and receptor for activation of nuclear factor-kB ligand (RANKL) in osteoclast (OC) precursors. Sulforaphane, an aliphatic isothiocyanate, is a known cancer chemo-preventative agent with anti-oxidative properties. Nuclear factor-kB (NF-kB) is a critical transcription factor in RANKL-induced osteoclastogenesis, and electrophoretic mobility shift assays (EMSAs) and assay of NF-kB-mediated secreted alkaline phosphatase (SEAP) revealed that sulforaphane selectively inhibited NF-kappaB activation induced by RANKL.

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Stimulation of murine macrophages with corn silk induced cyclooxygenase (COX)-2 with secretion of PGE2. Expression of COX-2 was inhibited by pyrolidine dithiocarbamate (PDTC), and increased DNA binding by nuclear factor kappa B (NF-kappaB), indicating that COX-2 induction proceeds also via the NF-kappaB signaling pathway. A specific inhibitor of COX-2 decreased the expression level of inducible nitric oxide synthase (iNOS) stimulated by corn silk.

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We found that treatment of osteoclast (OC) precursors with soluble glucocorticoid-induced tumor necrosis factor receptor (sGITR) promoted osteoclastogenesis in the presence of macrophage colony-stimulating factor (M-CSF) and receptor for activation of nuclear factor-kappaB ligand (RANKL). Low levels of GITR and its ligand were expressed on the surface of OC precursor cells after incubation with RANKL. Stimulation of osteoclastogenesis by sGITR was blocked by neutralization with anti-GITR ligand antibody (Ab), whereas endogenous GITR did not affect osteoclastogenesis, indicating that enhancement of osteoclastogenesis by sGITR involves signaling via GITR ligand.

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In order to clarify the mechanism by which soluble GITR (sGITR) inhibits the survival of murine macrophages we examined its effect on the macrophage cell cycle. Soluble GITR induced G1 phase arrest followed by apoptosis. It also reduced the expression of cyclins D2 and A, and of cdk4, resulting in reduced cdk2 and cdk4 activities.

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Glucocorticoid-induced TNF receptor (GITR) was a new member of the TNF/nerve growth factor receptor (TNFR/ NGFR) family and induced in murine T cells by dexamathasone. Recombinant soluble GITR (sGITR) induced an inflammation in peritoneal membrane and changes in spleen after i.p.

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Earlier study showed that glucocorticoid induced tumor necrosis factor receptor (GITR), a new TNFR family, activated murine macrophages to express inducible nitric oxide synthase (iNOS) and to generate nitric oxide (NO). A possible involvement of pro-inflammatory cytokines on NO production by GITR was investigated in vitro systems and signaling molecules contributing to sGITR-induced iNOS production are determined in Raw 264.7 cells, a murine macrophage cell line.

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Glucocorticoid induced tumor necrosis factor receptor (GITR), a new TNFR family, increased production of matrix matalloproteinase (MMP-9) in murine macrophages. Murine macrophages produced a band of gelatinolytic activity at 100 kDa when stimulated for 18 h with soluble GITR. MMP-9 was identified by gelatin zymography and Western blot.

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With the completion of the nucleotide sequences of several complex eukaryotic genomes, tens of thousands of genes have been predicted. However, this information has to be correlated with the functions of those genes to enhance our understanding of biology and to improve human health care. The Drosophila transposon P-element-induced mutations are very useful for directly connecting gene products to their biological function.

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The JAK/STAT signal transduction pathway regulates many developmental processes in Drosophila. However, the functional mechanism of this pathway is poorly understood. In this report, we identify the Drosophila cyclin-dependent kinase 4 (Cdk4), which exhibits embryonic mutant phenotypes identical to those in the Hopscotch/JAK kinase and stat92E/STAT mutations.

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Stimulation of murine macrophages with recombinant soluble glucocorticoid induced tumour necrosis factor receptor (GITR) induced cyclooxygenase (COX)-2 protein and generated significant amounts of PGE(2). Previous result demonstrated that macrophages express GITR and GITR ligand constitutively. Induction of COX-2 was synergistic with interferon (INF)-gamma.

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