Yonsei Fraunhofer IZFP Medical Device Lab YFMED

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Intensive morphometric analysis of enormous alterations in skeletal bone system with micro-CT for AHNAK−/− mice

2020 , Kim, I.Y. , Yi, S.S. , Shin, J.H. , Kim, Y.N. , Ko, C.-Y. , Kim, H.S. , Lee, S.Y. , Bae, Y.S. , Seong, J.K.

AHNAK has been reported to be involved in actin cytoskeleton rearrangement of some cell types, calcium homeostasis, and activation of T cells. Although the functional role of AHNAK in muscle cells, epidermis, and brain has been determined, its association with apparent clinical impairment has not been found yet. During phenotypic analysis of AHNAK knock out (KO) mice for many years, we observed that AHNAK KO mice showed very slow growth. Snouts of these animals were very short, and their bones were easily broken compared to normal mice. It is known that AHNAK is closely related to calcium. However, intensive morphological studies on phenotypes of bone have yet been reported for AHNAK. Thus, the objective of the present study was to analyze the morphology of skull, mandibular, limbs, and caudal bones of AHNAK KO mice intensively using micro-CT with many factors for various ages of these mice (6 weeks, 18 weeks, and 40 weeks). As a result, it was found that the facial region of AHNAK KO mouse showed a large difference in mandible than skull. Their both femur and tibia were shortened, and bone strength was also significantly decreased compared to normal mice. Particularly, the tail bone of AHNAK KO mice exhibited morphological abnormality by age. Taken together, these results suggest that AHNAK plays an important role in bone shape, development, and metabolism. Although our results demonstrated that AHNAK has a distinct role in bone, further investigations are needed to determine various features of bone metabolism related to AHNAK in the future.

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Melatonin suppresses autophagy induced by clinostat in preosteoblast MC3T3-E1 cells

2016 , Yoo, Yeong-Min , Han, Tae-Young , Kim, Han Sung

Microgravity exposure can cause cardiovascular and immune disorders, muscle atrophy, osteoporosis, and loss of blood and plasma volume. A clinostat device is an effective ground-based tool for simulating microgravity. This study investigated how melatonin suppresses autophagy caused by simulated microgravity in preosteoblast MC3T3-E1 cells. In preosteoblast MC3T3-E1 cells, clinostat rotation induced a significant time-dependent increase in the levels of the autophagosomal marker microtubule-associated protein light chain (LC3), suggesting that autophagy is induced by clinostat rotation in these cells. Melatonin treatment (100, 200 nM) significantly attenuated the clinostat-induced increases in LC3 II protein, and immunofluorescence staining revealed decreased levels of both LC3 and lysosomal-associated membrane protein 2 (Lamp2), indicating a decrease in autophagosomes. The levels of phosphorylation of mammalian target of rapamycin (p-mTOR) (Ser2448), phosphorylation of extracellular signal-regulated kinase (p-ERK), and phosphorylation of serine-threonine protein kinase (p-Akt) (Ser473) were significantly reduced by clinostat rotation. However, their expression levels were significantly recovered by melatonin treatment. Also, expression of the Bcl-2, truncated Bid, Cu/Zn- superoxide dismutase (SOD), and Mn-SOD proteins were significantly increased by melatonin treatment, whereas levels of Bax and catalase were decreased. The endoplasmic reticulum (ER) stress marker GRP78/BiP, IRE1a, and p-PERK proteins were significantly reduced by melatonin treatment. Treatment with the competitive melatonin receptor antagonist luzindole blocked melatonin-induced decreases in LC3 II levels. These results demonstrate that melatonin suppresses clinostat-induced autophagy through increasing the phosphorylation of the ERK/Akt/mTOR proteins. Consequently, melatonin appears to be a potential therapeutic agent for regulating microgravity-related bone loss or osteoporosis.

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Effects of Cymbidium root ethanol extract on atopic dermatitis

2016 , Kim, W.J. , Cha, H.S. , Lee, M.H. , Kim, S.Y. , Kim, S.H. , Kim, T.J.

Cymbidium has known antibacterial and antiedema activity and has been used as an ingredient in cosmetics and fragrances. The effects of Cymbidium ethanol extract (CYM) on allergic response and the underlying mechanisms of action have not been reported. Therefore, the purpose of this study was to determine the effect of CYM on allergic responses. Topical application of CYM was effective against immunoglobulin E (IgE)/dinitrophenyl-conjugated bovine serum albumin-(DNP-BSA-) induced degranulation of RBL-2H3 cells and anaphylaxis in ICR mice. An allergic dermatitis-like mouse model was used to evaluate the therapeutic potential of CYM in vivo. Continuous application of 2,4-dinitrochlorobenzene (DNCB) not only induced dermatitis in ICR mice but also aggravated the skin lesioning. However, the application of CYM decreased skin lesion severity, scratching behavior, and IgE levels. In addition, CYM downregulated the expression of the proinflammatory cytokines interleukin-(IL-) 4, IL-13, and tumor necrosis factor- (TNF-)alpha. Studies of signal transduction pathways showed that CYM suppressed the phosphorylation of spleen tyrosine kinase (Syk), an upstream molecule. It also inhibited the phosphorylation of Akt, phospholipase C-(PLC-)gamma, and mitogen-activated protein kinase kinase kinase (MEKK). These results indicate that CYM may be effective in preventing and reducing allergic response and may have therapeutic potential as an antiallergic agent in disorders such as atopic dermatitis.

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Enhancement of bone quality and longitudinal growth due to free-fall motion in growing rats

2015 , Cho, S. , Eom, S. , Seo, D.-H. , Park, J. , Ko, C.-Y. , Kim, H.S.

Objectives: This study is to investigate the synchronous phenomena between bone quality and longitudinal length in a same subject affected by landing exercise. Physical exercise on the ground induces external loading to human body due to resistance from ground which can activate bone generation or remodeling. Especially, when the impact stimulation is applied to bone, it may improve bone quality and lengthening. Methods: 6-week-old male Wistar rats were randomly allocated to one of two conditions: free fall from 40 cm-height (I40; n = 7), and control (IC; n = 7). The impact stimulations were administered to the free fall groups, 10 times/day, and 5 days/week for 8 weeks. Structural parameters and longitudinal length of tibia were measured to quantitatively evaluate the variation in morphological characteristics and bone length with maturing. Results: The landing impact seems to be commonly effective on the enhancement of bone quality as well as longitudinal growth. Howe ver, the extent of enhancement may be more dominant in bone quality than longitudinal growth. On the other hand, the ratio of longitudinal growth seems to be dependent on the duration of stimuli whereas the enhancement of bone quality does not. Conclusions: This study verified that free-falls exercise can be effective on the enhancement of bone qualities and promotion of vertical growth in long bones. We expect that it might be possible for the moderate impact stimulation to be proposed as an aid for prevention of bone loss and promotion of bone lengthening. © 2015, Korean Society of Medical and Biological Engineering and Springer.

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Poly(lactic-co-glycolic acid) nanoparticles potentiate the protective effect of curcumin against bone loss in ovariectomized rats

2017 , Ahn, J. , Jeong, J. , Lee, H. , Sung, M.-J. , Jung, C.H. , Lee, H. , Hur, J. , Park, J.H. , Jang, Y.J. , Ha, T.Y.

Osteoporosis increases fragility fractures and is a major health issue in the elderly. Curcumin, an active constituent of Curcuma longa, was reported to exert a beneficial effect on osteoporotic bone loss. However, poor aqueous solubility has limited its pharmacological efficacy. Although application of poly(lactic-co-glycolic acid) (PLGA) nanoparticles as carriers for curcumin was demonstrated to improve the bioavailability of curcumin, the effect of curcumin-loaded PLGA (C-P) nanoparticles on bone health has not been investigated. To examine the therapeutic potential of C-P, we prepared C-P nanoparticles and confirmed curcumin was successfully encapsulated within the PLGA polymer. Ovariectomy (OVX)-induced bone loss was found to be ameliorated in rats fed with curcumin or C-P. The in vitro release study showed a typical biphasic pattern with an initial burst and following sustained release. Measurement of bone mineral density and observation of trabecular microarchitecture showed that C-P was more effective than free curcumin against osteoporosis. A qRT-PCR analysis demonstrated that C-P significantly improved bone remodeling. These results suggest that encapsulation with PLGA enhances the protective effect of curcumin against OVX-induced bone loss. This approach could be a promising strategy to improve the therapeutic index of phytochemicals against osteoporosis.

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Oral delivery of zoledronic acid by non-covalent conjugation with lysine-deoxycholic acid

2016 , Jeon, O.-C. , Seo, D.-H. , Kim, H.-S. , Byun, Y. , Park, J.W.

We assessed the possibility of changing the route of administration of zoledronic acid to an oral dosage form and its therapeutic efficacy in an estrogen-deficient osteoporosis rat model. To enhance oral bioavailability, we formed an ionic complex by electrostatic conjugation of zoledronic acid with lysine-linked deoxycholic acid (Lys-DOCA, an oral absorption enhancer). After forming the complex, the characteristic crystalline features of pure zoledronic acid disappeared completely in the powder X-ray diffractogram and differential scanning calorimetry thermogram, indicating that zoledronic acid existed in an amorphous form in the complex. In vitro permeabilities of zoledronic acid/Lys-DOCA (1:1) (ZD1) and zoledronic acid/Lys-DOCA (1:2) (ZD2) complex across Caco-2 cell monolayers were 2.47- and 4.74-fold higher than that of zoledronic acid, respectively. Upon intra-jejunal administration to rats, the intestinal absorption of zoledronic acid was increased significantly and the resulting oral bioavailability of the ZD2 complex was determined to be 6.76 +/- 2.59% (0.548 +/- 0.161% for zoledronic acid). Ovariectomized (OVX) rats showed 122% increased bone mineral density versus the OVX control at 12 weeks after treatment with once weekly oral administration of ZD2 complex (16 mu g/kg of zoledronic acid). Furthermore, rats treated with ZD2 complex orally showed significant improvement in the parameters of trabecular microarchitecture and bone strength: 149% higher bone volume fraction (BV/TV), 115% higher trabecular number (Tb.N), and 56% higher mean maximum load (F-max) than in the OVX group. The trabecular microstructure and bone mechanical properties in the oral zoledronic acid group were not significantly changed compared with the OVX control. Thus, the oral ZD2 complex inhibited osteoporosis progression effectively by promoting osteogenesis and trabecular connectivity. The oral ZD2 complex would be expected to improve patient compliance by replacing the conventional injectable form and expand the indications, to include prophylaxis for osteoporosis and bone metastases.

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Data of intracellular insulin protein reduced by autophagy in INS-1E cells

2016 , Kim, H.S. , Yoo, Y.-M.

Autophagy appears to be involved in maintaining normal intracellular insulin content by accelerating the insulin degradation rate in β-cells (Marsh et al., 2007) [1]. 2-deoxy-d-glucose (2-DG) is metabolized by hexokinase, and acts as an inhibitor of glycolysis. 2-DG triggers glucose deprivation without altering other nutrients or metabolic pathways (Aghaee et al., 2012) [2], and appears to be an ideal tool for studying autophagy. Rapamycin induced upregulation of autophagy in both cultured isolated islets and pancreatic β-cells (Tanemura et al., 2012) [3]. Here, we examined that 2-DG or rapamycin-induced autophagy may decrease the production of intracellular insulin in INS-1E insulinoma cells. Data showed that autophagy was increased by 2-DG or rapamycin by Western blotting and Immunofluorescence staining analyses. Also, intracellular insulin decreased by 2-DG or rapamycin. Furthermore, the autophagy inhibitors, bafilomycin A1 and/or 3-methyladenine, in the presence o r absence of 2-DG or rapamycin increased intracellular insulin in INS-1E insulinoma cells.

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Coptis japonica Makino extract suppresses Angiogenesis through regulation of cell cycle-related proteins

2016 , Kim, S.H. , Kim, E.-C. , Kim, W.-J. , Lee, M.-H. , Kim, S.-Y. , Kim, T.-J.

Angiogenesis, neovascularization from pre-existing vessels, is a key step in tumor growth and metastasis, and anti-angiogenic agents that can interfere with these essential steps of cancer development are a promising strategy for human cancer treatment. In this study, we characterized the anti-angiogenic effects of Coptis japonica Makino extract (CJME) and its mechanism of action. CJME significantly inhibited the proliferation, migration, and invasion of vascular endothelial growth factor (VEGF)-stimulated HUVECs. Furthermore, CJME suppressed VEGF-induced tube formation in vitro and VEGF-induced microvessel sprouting ex vivo. According to our study, CJME blocked VEGF-induced cell cycle transition in G1. CJME decreased expression of cell cycle-regulated proteins, including Cyclin D, Cyclin E, Cdk2, and Cdk4 in response to VEGF.

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Anti-skeletal muscle atrophy effect of Oenothera odorata root extract via reactive oxygen species-dependent signaling pathways in cellular and mouse model

2016 , Lee, Y.-H. , Kim, W.-J. , Lee, M.-H. , Kim, S.-Y. , Seo, D.-H. , Kim, H.-S. , Gelinsky, M. , Kim, T.-J.

Skeletal muscle atrophy can be defined as a decrease of muscle volume caused by injury or lack of use. This condition is associated with reactive oxygen species (ROS), resulting in various muscular disorders. We acquired 2D and 3D images using micro-computed tomography in gastrocnemius and soleus muscles of sciatic-denervated mice. We confirmed that sciatic denervation-small animal model reduced muscle volume. However, the intraperitoneal injection of Oenothera odorata root extract (EVP) delayed muscle atrophy compared to a control group. We also investigated the mechanism of muscle atrophy's relationship with ROS. EVP suppressed expression of SOD1, and increased expression of HSP70, in both H2O2-treated C2C12 myoblasts and sciatic-denervated mice. Moreover, EVP regulated apoptotic signals, including caspase- 3, Bax, Bcl-2, and ceramide. These results indicate that EVP has a positive effect on reducing the effect of ROS on muscle atrophy.

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Antiangiogenic Activity of Acer tegmentosum Maxim Water Extract in Vitro and in Vivo

2015 , Kim, E.C. , Kim, S.H. , Piao, S.J. , Kim, T.J. , Bae, K. , Kim, H.S. , Hong, S.S. , Lee, B.I. , Nam, M.

Angiogenesis, the formation of new blood vessels, is critical for tumor growth and metastasis. Notably, tumors themselves can lead to angiogenesis by inducing vascular endothelial growth factor (VEGF), which is one of the most potent angiogenic factors. Inhibition of angiogenesis is currently perceived as one of the most promising strategies for the blockage of tumor growth. In this study, we investigated the effects of Acer tegmentosum maxim water extract (ATME) on angiogenesis and its underlying signal mechanism. We studied the antiangiogenic activity of ATME by using human umbilical vein endothelial cells (HUVECs). ATME strongly inhibited VEGF-induced endothelial cell proliferation, migration, invasion, and tube formation, as well as vessel sprouting in a rat aortic ring sprouting assay. Moreover, we found that the p44/42 mitogen activated protein (MAP) kinase signaling pathway is involved in the inhibition of angiogenesis by ATME. Moreover, when we performed the in vivo matrigel plug assay, VEGF-induced angiogenesis was potently reduced when compared to that for the control group. Taken together, these results suggest that ATME exhibits potent antiangiogenic activity in vivo and in vitro and that these effects are regulated by the extracellular regulated kinase (ERK) pathway.

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