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11.
Keratins make up a major portion of epithelial intermediate filament proteins. The widely diverse keratins are found in both the small and large intestines. The human intestine mainly expresses keratins 8, 18, 19, and 20. Many of the common roles of keratins are for the integrity and stability of the epithelial cells. The keratins also protect the cells and tissue from stress and are biomarkers for some diseases in the organs. Although an increasing number of studies have been performed regarding keratins, the roles of keratin in the intestine have not yet been fully understood. This review focuses on discussing the roles of keratins in the intestine. Diverse studies utilizing mouse models and samples from patients with intestinal diseases in the search for the association of keratin in intestinal diseases have been summarized. 相似文献
12.
Athapaththu Mudiyanselage Gihan Kavinda Athapaththu Sobarathne Senel Sanjaya Kyoung Tae Lee Wisurumuni Arachchilage Hasitha Maduranga Karunarathne Yung Hyun Choi Sung-Pyo Hur Gi-Young Kim 《International journal of molecular sciences》2023,24(1)
Pinostrobin is a dietary flavonoid found in several plants that possesses pharmacological properties, such as anti-cancer, anti-virus, antioxidant, anti-ulcer, and anti-aromatase effects. However, it is unclear if pinostrobin exerts anti-melanogenic properties and, if so, what the underlying molecular mechanisms comprise. Therefore, we, in this study, investigated whether pinostrobin inhibits melanin biosynthesis in vitro and in vivo, as well as the potential associated mechanism. Pinostrobin reduced mushroom tyrosinase activity in vitro in a concentration-dependent manner, with an IC50 of 700 μM. Molecular docking simulations further revealed that pinostrobin forms a hydrogen bond, as well as other non-covalent interactions, between the C-type lectin-like fold and polyphenol oxidase chain, rather than the previously known copper-containing catalytic center. Additionally, pinostrobin significantly decreased α-melanocyte-stimulating hormone (α-MSH)-induced extracellular and intracellular melanin production, as well as tyrosinase activity, in B16F10 melanoma cells. More specifically, pinostrobin inhibited the α-MSH-induced melanin biosynthesis signaling pathway by suppressing the cAMP–CREB–MITF axis. In fact, pinostrobin also attenuated pigmentation in α-MSH-stimulated zebrafish larvae without causing cardiotoxicity. The findings suggest that pinostrobin effectively inhibits melanogenesis in vitro and in vivo via regulation of the cAMP–CREB–MITF axis. 相似文献
13.
Md Saifur Rahman Md Badrul Alam Young Kyun Kim Mst Hur Madina Ismail Fliss Sang Han Lee Jin Cheol Yoo 《International journal of molecular sciences》2021,22(10)
In this study, we investigate the immunomodulatory effects of a novel antimicrobial peptide, YD1, isolated from Kimchi, in both in vitro and in vivo models. We establish that YD1 exerts its anti-inflammatory effects via up-regulation of the Nrf2 pathway, resulting in the production of HO-1, which suppresses activation of the NF-κB pathway, including the subsequent proinflammatory cytokines IL-1β, IL-6, and TNF-α. We also found that YD1 robustly suppresses nitric oxide (NO) and prostaglandin E2 (PGE2) production by down-regulating the expression of the upstream genes, iNOS and COX-2, acting as a strong antioxidant. Collectively, YD1 exhibits vigorous anti-inflammatory and antioxidant activity, presenting it as an interesting potential therapeutic agent. 相似文献
14.
Muscimol Directly Activates the TREK-2 Channel Expressed in GABAergic Neurons through Its N-Terminus
Eun-Jin Kim Oh-Sang Kwon Chang-Gi Hur Marie Merci Nyiramana Dong-Kun Lee Seong-Geun Hong Jaehee Han Dawon Kang 《International journal of molecular sciences》2021,22(17)
The two-pore domain K+ (K2P) channel, which is involved in setting the resting membrane potential in neurons, is an essential target for receptor agonists. Activation of the γ-aminobutyric acid (GABA) receptors (GABAAR and GABABR) reduces cellular excitability through Cl- influx and K+ efflux in neurons. Relatively little is known about the link between GABAAR and the K+ channel. The present study was performed to identify the effect of GABAR agonists on K2P channel expression and activity in the neuroblastic B35 cells that maintain glutamic acid decarboxylase (GAD) activity and express GABA. TASK and TREK/TRAAK mRNA were expressed in B35 cells with a high level of TREK-2 and TRAAK. In addition, TREK/TRAAK proteins were detected in the GABAergic neurons obtained from GABA transgenic mice. Furthermore, TREK-2 mRNA and protein expression levels were markedly upregulated in B35 cells by GABAAR and GABABR agonists. In particular, muscimol, a GABAAR agonist, significantly increased TREK-2 expression and activity, but the effect was reduced in the presence of the GABAAR antagonist bicuculine or TREK-2 inhibitor norfluoxetine. In the whole-cell and single-channel patch configurations, muscimol increased TREK-2 activity, but the muscimol effect disappeared in the N-terminal deletion mutant. These results indicate that muscimol directly induces TREK-2 activation through the N-terminus and suggest that muscimol can reduce cellular excitability by activating the TREK-2 channel and by inducing Cl- influx in GABAergic neurons. 相似文献
15.
Hur JH Kim KM Chang M Lee SR Lee D Lee CB Lee MJ Kim YB Kim CJ Chung UI 《Nanotechnology》2012,23(22):225702
We report a physical model for multilevel switching in oxide-based bipolar resistive memory (ReRAM). To confirm the validity of the model, we conduct experiments with tantalum-oxide-based ReRAM of which multi-resistance levels are obtained by reset voltage modifications. It is also noticeable that, in addition to multilevel switching capability, the ReRAM exhibits extremely different switching timescales, i.e. of the order of 10(-7)?s to 10(0)?s, with regard to reset voltages of only a few volts difference which can be well explained by our model. It is demonstrated that with this simple model, multilevel switching behavior in oxide bipolar ReRAM can be described not only qualitatively but also quantitatively. 相似文献
16.
Viet Hung Pham Thanh Truong Dang Tran Viet Cuong Seung Hyun Hur Byung-Seon Kong Eui Jung Kim Jin Suk Chung 《Korean Journal of Chemical Engineering》2012,29(5):680-685
We report the effect of temperature on the extent of graphene oxide reduction by hydrazine and the dispersibility of the resulting
chemically converted graphene (CCG) in polar organic solvents. The extent of graphene oxide reduction at high temperatures
was only slightly higher than at low temperatures (30–50 °C), while the dispersibility of the resulting CCG in organic solvents
decreased markedly with increasing temperature. The low dispersibility of CCGs prepared at high temperatures was greatly affected
by reduction and influenced by the formation of an irreversible agglomerate of CCG at high temperatures. The reduction of
graphene oxide at low temperatures is necessary to prepare highly dispersible CCG in organic solvents. CCG prepared at 30
°C is dispersible in N-methyl-2-pyrrolidone concentrations as high as 0.71 mg/mL. The free-standing paper made of this CCG
possessed an electrical conductivity of more than 22,000 S/m, one of the highest values ever reported. 相似文献
17.
Dae‐Hyeon Kim Mi‐Ri Joung In‐Tae Seo Joon Hur Jong‐Hyun Kim Bo‐Yun Kim Hwack‐Joo Lee Sahn Nahm 《Journal of the American Ceramic Society》2014,97(12):3897-3903
Dielectric and piezoelectric properties of CuO‐added KNbO3 (KN) ceramics were investigated. The CuO reacted with the Nb2O5, formed a CuO–Nb2O5‐related liquid phase during the sintering, and assisted the densification of the KN ceramics at low temperatures. Moreover, some of the Cu2+ ions replaced the Nb5+ ions in the matrix and behaved as a hardener. The dielectric and piezoelectric properties of the KN ceramics were considerably influenced by the relative density. The 1.0 mol% CuO‐added KN ceramic sintered at 960°C for 1.0 h, which showed a maximum relative density, exhibited a high phase angle of 86.9°, Pr of 14.8 μC/cm2, and Ec of 1.8 kV/mm. This specimen also exhibited good dielectric and piezoelectric properties: εT33/εo of 364, d33 of 122 pC/N, kp of 0.29, and Qm of 611. 相似文献
18.
Hyun-Moo Hur Joon-Hyuk Park Won-Hee You Tae-Won Park 《Journal of Mechanical Science and Technology》2009,23(10):2790-2800
A study was conducted to analyze the influence of wheel profile wear on running stability by using a 1/5 scale bogie model.
The critical speed was analyzed by constructing a dynamic model for the bogie model. And the 1/5 scale bogie and a scaled
roller rig prototype were manufactured to verify the feasibility of applying the scale model; a critical speed test was conducted
for worn wheel profile samples. The test results for the scale model were consistent with the simulation results for the scale
model within the range of 5% or less. Also, the variation of the critical speed of the scale model for the wheel profile wear
shows a similar trend with the analysis results of the full scale model. Therefore, using the scale model to analyze the influence
of wheel profile wear on running stability shows sufficient feasibility as a model to analyze the stability of a full scale
bogie. 相似文献
19.
A Distributed Medium Access Control (D-MAC) protocol based on UWB for high-rate Wireless Personal Area Networks is specified by the WiMedia Alliance. D-MAC protocol is suitable for ubiquitous connection in home networks, military/medical applications due to its inexpensive cost, low power consumption, high data rate, and distributed approach. In contrast to IEEE 802.15.3, D-MAC makes all devices have the same functionality. And its networks are self-organized and provide devices with functions such as access to the medium, channel allocation to devices, data transmission, quality of service and synchronization in a distributed manner. D-MAC fundamentally removes the problems of the centralized MAC approach revealed at IEEE 802.15.3 MAC by adopting a distributed architecture. However, the current D-MAC can’t prevent QoS degradations, occurred by mobile nodes with low data rate due to bad channel status, which cause critical problems in QoS provisioning to isochronous streams and mobile applications. Therefore, we propose a distributed cooperative MAC protocol for multi-hop WiMedia networks using virtual MIMO links. Based on instantaneous Channel State Information among WiMedia devices, our proposed protocol can intelligently select the transmission path with higher data rate to provide advanced QoS with minimum delay for real-time multimedia streaming services. 相似文献
20.
Min‐Seok Kim Xing‐Hua Ma Ki‐Hyun Cho Seung‐Yeol Jeon Kahyun Hur Yun‐Mo Sung 《Advanced materials (Deerfield Beach, Fla.)》2018,30(6)
Despite tellurium being less abundant in the Earth's crust than gold, platinum, or rare‐earth elements, the number of industrial applications of tellurium has rapidly increased in recent years. However, to date, many properties of tellurium and its associated compounds remain unknown. For example, formation mechanisms of many tellurium nanostructures synthesized so far have not yet been verified, and it is unclear why tellurium can readily transform to other compounds like silver telluride by simply mixing with solutions containing silver ions. This uncertainty appears to be due to previous misunderstandings about the tellurium structure. Here, a new approach to the tellurium structure via synthesized structures is proposed. It is found that the proposed approach applies not only to these structures but to all other tellurium nanostructures. Moreover, some unique tellurium nanostructures whose formation mechanism are, until now, unconfirmed can be explained. 相似文献