• BMB Reports
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• v.51 no.10
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• pp.508-513
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• 2018

Fibronectin fragments found in the synovial fluid of patients with osteoarthritis (OA) induce the catabolic responses in cartilage. Nuclear high-mobility group protein Box 1 (HMGB1), a damage-associated molecular pattern, is responsible for the regulation of signaling pathways related to cell death and survival in response to various stimuli. In this study, we investigated whether changes induced by 29-kDa amino-terminal fibronectin fragment (29-kDa FN-f) in HMGB1 expression influences the pathogenesis of OA via an HMGB1-modulated autophagy signaling pathway. Human articular chondrocytes were enzymatically isolated from articular cartilage. The level of mRNA was measured by quantitative real-time PCR. The expression of proteins was examined by western blot analysis, immnunofluorescence assay, and enzyme-linked immunosorbent assay. Interaction of proteins was evaluated by immunoprecipitation. The HMGB1 level was significantly lower in human OA cartilage than in normal cartilage. Although 29-kDa FN-f significantly reduced the HMGB1 expression at the mRNA and protein levels 6 h after treatment, the cytoplasmic level of HMGB1 was increased in chondrocytes treated with 29-kDa FN-f, which significantly inhibited the interaction of HMGB1 with Beclin-1, increased the interaction of Bcl-2 with Beclin-1, and decreased the levels of Beclin-1 and phosphorylated Bcl-2. In addition, the level of microtubule-associated protein 1 light chain 3-II, an autophagy marker, was down-regulated in chondrocytes treated with 29-kDa FN-f, whereas the effect was antagonized by mTOR knockdown. Furthermore, prolonged treatment with 29-kDa FN-f significantly increased the release of HMGB1 into the culture medium. These results demonstrated that 29-kDa FN-f inhibits chondrocyte autophagy by modulating the HMGB1 signaling pathway.

• Applied Microscopy
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• v.28 no.2
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• pp.193-205
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• 1998

The Urechis unicinctus sperm and spermatogenic cells prepared from the testis are investigated to identify $\alpha-tubulin$ of axoneme microtubules using mouse monoclonal $anti-\alpha-tubulin$ as the first Ab and Gold(10nm) conjugated goat anti-mouse IgG as the Ab marker. The Ag-Ab reaction analyzed excellently the localization of $\alpha-tubulin$ and the gold particles incorporated with the proximal and distal centrioles, manchette microtubules, and flagellum. The gold particles can be also observed in the spermatogenic cells while the cells are still in sperm ball which is composed of a somatic cell and spermatogenic cells. The sperm ball is the functional unit of sperm production in U unicinctus testis. The spermatids are developed from the spermatogenic cells in the sperm ball and released into the testis cavity through a cortical cytoplasmic opening. The spermatid architectures are similar with the mature sperm of the testis cavity in aspects of shape of discoid acrosome, degree of nuclear condensation and ring type of mitochondrion. However, the distal centriole connecting with the flagella can be observed from the mature sperm while the both proximal and distal centrioles reveal only in the spermatids. The proximal centriole is directly connected with nuclear outer membrane during the stage of nuclear condensation and oriented perpendicularly to the distal centriole whose axis coinciding with the longitudinal axis of the spermatozoon. There are indications that the distal centriole is intimately associated with the polymerization of the flagellum. The manchette microtubules appear during spermatid development but the mature sperm have round head and no conspicuous middle piece.

• Journal of Life Science
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• v.33 no.1
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• pp.1-7
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• 2023

Intracellular cargo transport is mediated by molecular motor proteins, such as kinesin and cytoplasmic dynein. Kinesins make up a large subfamily of molecular motors. Kinesin-1 is a plus-end-directed molecular motor protein that moves various cargoes, such as organelles, protein complexes, and mRNAs, along a microtubule track. It consists of the kinesin superfamily protein (KIF) 5A, 5B, and 5C (also called kinesin heavy chains) and kinesin light chains (KLCs). Kinesin-1 interacts with many different binding proteins through its carboxyl (C)-terminal region of KIF5s and KLCs, but their binding proteins have not yet been fully identified. In this study, a yeast two-hybrid assay was used to identify the proteins that interact with the KIF5A specific C-terminal region. The assay revealed an interaction between KIF5A and glutamate-rich 4 (ERICH4). ERICH4 bound to the KIF5A specific the C-terminal region but did not interact with the C-terminal region of KIF5B or KIF3A (a motor protein of kinesin-2). In addition, KIF5A did not interact with another isoform, ERICH1. Glutathione S-transferase (GST) pull-downs showed that KIF5A interacts with GST-ERICH4 and GST-ERICH4-amino (N)-terminal but not with GST-ERICH4-C or GST alone. When co-expressed in HEK-293T cells, ERICH4 co-localized with KIF5A and co-immunoprecipitated with KIF5A and KLC but not KIF3B. Together, our findings suggest that ERICH4 is capable of binding to KIF5A and that it may serve as an adaptor protein that links kinesin-1 with cargo.

• Journal of The Korean Dental Society of Anesthesiology
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• v.14 no.2
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• pp.101-106
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• 2014

Background: Remifentanil, an ultra-short-acting mu-opioid receptor agonist, is unique from other opioids because of its esterase-based metabolism, minimal accumulation, and very rapid onset and offset of clinical action. Remifentanil can prevent the inflammatory response and can suppress inducible nitric oxide synthase expression in a septic mouse model. However, the effects of remifentanil on human keratinocyte and autophagy have yet to be fully elucidated during hypoxia-reoxygenation. Here we investigated whether remifentanil confers protective effect against hypoxia-reoxygenation in human keratinocyte and, if so, whether autophagy mediates this effect. Methods: The human keratinocytes were cultured under 1% oxygen tension. The cells were gassed with 94% $N_2$, and 5% $CO_2$ and incubated for 24 h at $37^{\circ}C$. To determine whether the administration of affects human keratinocytes hypoxia-reoxygenation injury, cells were then exposed to various concentrations of remifentanil (0.01, 0.1, 0.5 and 1 ng/ml) for 2 h. After remifentanil treatment, to simulate reoxygenation and recovery, the cells were reoxygenated for 12 h at $37^{\circ}C$. Control group did not receive remifentanil treatment. Normoxia group did not receive hypoxia and remifentanil treatment for 36 h. 3-MA group was treated 3-methyladenine (3-MA) for 1h before remifentanil treatment. Cell viability was measured using a quantitative colorimetric assay with MTT, showing the mitochondrial activity of living cells. Cells were stained with fluorescence and analyzed with Western blot analysis to find out any relations with activation of autophagy. Results: Prominent accumulation of autophagic specific staining MDC was observed around the nuclei in RPT group HaCaT cells. Similarly, AO staining, red fluorescent spots appeared in RPT group HaCaT cells, while the Normoxia, control and 3-MA groups showed mainly green cytoplasmic fluorescence. We here examined activation of autophagy related protein under H/R-induced cells by Western blotting analysis. Atg5, Beclin-1, LC3-II (microtubule-associated protein 1 light chain 3 form II) and p62 was elevated in RPT group cells. But they were decreased when autophagy was suppressed by 3-MA (Fig. 5). Conclusions: Although the findings of this study are limited to an in vitro interpretation, we suggest that remifentanil may have a beneficial effect in the recovery of wound from hypoxia-reoxygenation injury.