• Title/Summary/Keyword: ClC channel

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Increase in Hypotonic Stress-Induced Endocytic Activity in Macrophages via ClC-3

  • Yan, Yutao;Ding, Yu;Ming, Bingxia;Du, Wenjiao;Kong, Xiaoling;Tian, Li;Zheng, Fang;Fang, Min;Tan, Zheng;Gong, Feili
    • Molecules and Cells
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    • v.37 no.5
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    • pp.418-425
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    • 2014
  • Extracellular hypotonic stress can affect cellular function. Whether and how hypotonicity affects immune cell function remains to be elucidated. Macrophages are immune cells that play key roles in adaptive and innate in immune reactions. The purpose of this study was to investigate the role and underlying mechanism of hypotonic stress in the function of bone marrow-derived macrophages (BMDMs). Hypotonic stress increased endocytic activity in BMDMs, but there was no significant change in the expression of CD80, CD86, and MHC class II molecules, nor in the secretion of TNF-${\alpha}$ or IL-10 by BMDMs. Furthermore, the enhanced endocytic activity of BMDMs triggered by hypotonic stress was significantly inhibited by chloride channel-3 (ClC-3) siRNA. Our findings suggest that hypotonic stress can induce endocytosis in BMDMs and that ClC-3 plays a central role in the endocytic process.

Extracellular ATP Stimulates $Na^+\;and\;Cl^-$ Transport through the Activation of Multiple Purinergic Receptors on the Apical and Basolateral Membranes in M-1 Mouse Cortical Collecting Duct Cells

  • Jung, Jin-Sup;Hwang, Sook-Mi;Lee, Ryang-Hwa;Kang, Soo-Kyung;Woo, Jae-Suk;Kim, Yong-Keun
    • The Korean Journal of Physiology and Pharmacology
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    • v.5 no.3
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    • pp.231-241
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    • 2001
  • The mammalian cortical collecting duct (CCD) plays a major role in regulating renal NaCl reabsorption, which is important in $Na^+$ and $Cl^-$ homeostasis. The M-1 cell line, derived from the mouse cortical collecting duct, has been used as a mammalian model of the study on the electrolytes transport in CCD. M-1 cells were grown on collagen-coated permeable support and short circuit current $(I_{sc})$ was measured. M-1 cells developed amiloride-sensitive current $5{\sim}7$ days after seeding. Apical and basolateral addition of ATP induced increase in $I_{sc}$ in M-1 cells, which was partly retained in $Na^+-free$ or $Cl^--free$ solution, indicating that ATP increased $Na^+$ absorption and $Cl^-$ secretion in M-1 cells. $Cl^-$ secretion was mediated by the activation of apical cystic fibrosis transmembrane regulator (CFTR) chloride channels and $Ca^{2+}-activated$ chloride channels, but $Na^+$ absorption was not mediated by activation of epithelal sodium channel (ENaC). ATP increased cAMP content in M-1 cells. The RT-PCR analysis demonstrated that M-1 cells express $P2Y_2,\;P2X_3\;and\;P2Y_4$ receptors. These results showed that ATP regulates $Na^+$ and $Cl^-$ transports via multiple P2 purinoceptors on the apical and basolateral membranes in M-1 cells.

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EFFECTS OF CADMIUM CHLORIDE ON GLUCOSE TRANSPORT IN 3T3-L1 ADIPOCYTES

  • Kim, M.H.;Kim, K.S.;Lee, H.B.;Chae, S.H.;Jung, A.Y.;Jo, Y.Y.;Kim, M.H.;Moon, C.K.
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.158.2-159
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    • 2003
  • Cadmium is well known as a toxic metal and has insulin mimicking effects in rat adipose tissue. To investigate the effect of CdCl2 on glucose transport and its mechanism, this study was performed in 3T3-L1 adipocytes. 10 and 25mM of CdCl2 exposed to cells for 12 hours increased 2-deoxyglucose uptake to 2.2 and 2.8 fold, respectively. Nifedipine, a calcium channel blocker, inhibited the 2-deoxyglucose uptake stimulated by CdCl2. (omitted)

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Characteristics of Plasma etching and Fabrication of Superconducting Flux Flow Transistor (플라즈마 식각 특성과 이를 이용한 초전도 자속 흐름 트랜지스터)

  • Kang, H.G.;Park, C.B.;Lee, K.S.;Kim, H.G.;Hwang, C.S.;Han, B.S.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.08a
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    • pp.138-141
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    • 2002
  • The channel of the superconducting Flux Flow Transistor has been fabricated with plasma etching method using ICP. The ICP conditions were 700 W of ICP power, 150 W of rf chuck power, 5 mTorr of the pressure in chamber and 1:1 of Ar : $Cl_2$, respectively. The channel etched by plasma gas showed superconducting characteristics of over 77 K and superior surface morphology. The critical current of SFFT was altered by varying the external applied current. As the external applied current increased from 0 to 12 mA, the critical current decreased from 28 to 22 mA. Then the obtained $r_m$ values were smaller than $0.1\Omega$ at a bias current of 40 mA. The current gain was about 0.5. Output resistance was below $0.2\Omega$.

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Acute Hypoxia Activates an ENaC-like Channel in Rat Pheochromocytoma (PC12) Cells

  • Bae, Yeon Ju;Yoo, Jae-Cheal;Park, Nammi;Kang, Dawon;Han, Jaehee;Hwang, Eunmi;Park, Jae-Yong;Hong, Seong-Geun
    • The Korean Journal of Physiology and Pharmacology
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    • v.17 no.1
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    • pp.57-64
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    • 2013
  • Cells can resist and even recover from stress induced by acute hypoxia, whereas chronic hypoxia often leads to irreversible damage and eventually death. Although little is known about the response(s) to acute hypoxia in neuronal cells, alterations in ion channel activity could be preferential. This study aimed to elucidate which channel type is involved in the response to acute hypoxia in rat pheochromocytomal (PC12) cells as a neuronal cell model. Using perfusing solution saturated with 95% $N_2$ and 5% $CO_2$, induction of cell hypoxia was confirmed based on increased intracellular $Ca^{2+}$ with diminished oxygen content in the perfusate. During acute hypoxia, one channel type with a conductance of about 30 pS (2.5 pA at -80 mV) was activated within the first 2~3 min following onset of hypoxia and was long-lived for more than 300 ms with high open probability ($P_o$, up to 0.8). This channel was permeable to $Na^+$ ions, but not to $K^+$, $Ca^+$, and $Cl^-$ ions, and was sensitively blocked by amiloride (200 nM). These characteristics and behaviors were quite similar to those of epithelial sodium channel (ENaC). RT-PCR and Western blot analyses confirmed that ENaC channel was endogenously expressed in PC12 cells. Taken together, a 30-pS ENaC-like channel was activated in response to acute hypoxia in PC12 cells. This is the first evidence of an acute hypoxia-activated $Na^+$ channel that can contribute to depolarization of the cell.

Functional Nanochannels to Control Ion Transportation with Monomolecule Selectivity (단일 이온 인식형 이송 제어 기능성 나노채널 기술)

  • Kim, Jeong Hwan;Lee, Eung-Sug;Whang, Kyung-Hyun;Yoo, Yeong-Eun;Yoon, Jae-Sung
    • Transactions of the KSME C: Technology and Education
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    • v.3 no.4
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    • pp.249-255
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    • 2015
  • Functional nanochannels were fabricated in order to control selective ion transportation with high permeability and low energy consumption. In this research, nanochannel platform fabrication process and surface functionalization process were developed. In addition, selective ion transportation and concentration measurement system was also set-up. By using fabricated multilayer metal membrane with electrical bias, 95% of ion ($Cl^-$) was blocked. This developed process is new-conceptional membrane fabrication technology and is expected to be applied to next-generation water purification/desalination, portable artifical kidney, and artificial sense organ.

Effect of Temperature on $H_2$ Spillover over $Pt/H_xMoO_3$ (Pt를 담지한 $H_xMoO_3$촉매의 수소 이동 속도에 미치는 온도의 영향)

  • 김진걸
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.5 no.2
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    • pp.114-117
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    • 2004
  • Rates of $H_2$ uptake into $Pt/MoO_3$ were measured for the noncalcined and $200^{\circ}C$ calcined $Pt/MoO_3$. Amount of $H_2$ uptake for $200^\circ{C}$calcined $Pt/MoO_3$ was greater than the amount of noncalcined $Pt/MoO_3$. From these two experiments, it was found that the rates of $H_2$ desorption were proportional to the increase of desorption temperature. XPS demonstrated that Cl reduced more faster in ITR after calcination at $200^{\circ}C$. This inducd smaller amount of residual chlorine at adlineation sites between Pt and $MoO_3$ substrates. This resulted in opening the more channel of hydrogen pathway into more $MoO_3$particles and controled the kinetics of hydrogen uptake.

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Role of Diacyl Glycerol (DAG) in Caprine Sperm Acrosomal Exocytosis Induced by Progesterone

  • Somanath, P.R.;Gandhi, K.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.8
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    • pp.1091-1097
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    • 2002
  • Capacitated goat spermatozoa generated diacyl glycerol (DAG) when suspended in Krebs-Ringer bicarbonate medium and induced by progesterone or $Ca^{2+}$ ionophore A23187. We have added Sn-1-oleoyl-2-acetyl glycerol externally, to study the effect of DAG in goat sperm acrosomal exocytosis. Addition of neomycin abolished the DAG generating capacity of progesterone in a dose dependent manner, suggesting the involvement of a phosphoinositidase C activated phospholipase C system in the process. The level of increase in phosphatidic acid was considerably low and was produced well after the DAG generation thereby suggesting the involvement of a DAG kinase which phosphorylates DAG to produce PA. The inhibition of progesterone mediated effect by inhibitors of $GABA_A/Cl^{-}$ channel and $Ca^{2+}$ channels further supports the evidence that the events of binding of agonist to the receptor(s), opening of $Ca^{2+}$ channels and the activation of phospholipase C are reconciled to perform the function of acrosome reaction in capacitated goat spermatozoa.

A Study on the Fabrication of p-type poly-Si Thin Film Transistor (TFT) Using Sequential Lateral Solidification(SLS) (SLS 공정을 이용한 p-type poly-Si TFT 제작에 관한 연구)

  • Lee, Yun-Jae;Park, Jeong-Ho;Kim, Dong-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.51 no.6
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    • pp.229-235
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    • 2002
  • This paper presents the fabrication of polycrystalline thin film transistor(TFT) using sequential lateral solidification(SLS) of amorphous silicon. The fabricated SLS TFT showed high Performance suitable for active matrix liquid crystal display(AMLCD). The SLS process involves (1) a complete melting of selected area via irradiation through a patterned mask, and (2) a precisely controlled pulse translation of the sample with respect to the mask over a distance shorter than the super lateral growth(SLG) distance so that lateral growth extended over a number of iterative steps. The SLS experiment was performed with 550$\AA$ a-Si using 308nm XeCl laser having $2\mu\textrm{m}$ width. Irradiated laser energy density is 310mJ/$\textrm{cm}^2$ and pulse duration time was 25ns. The translation distance was 0.6$\mu$m/pulse, 0.8$\mu$m/pulse respectively. As a result, a directly solidified grain was obtained. Thin film transistors (TFTs) were fabricated on the poly-Si film made by SLS process. The characteristics of fabricated SLS p -type poly-Si TFT device with 2$\mu\textrm{m}$ channel width and 2$\mu\textrm{m}$ channel length showed the mobility of 115.5$\textrm{cm}^2$/V.s, the threshold voltage of -1.78V, subthreshold slope of 0.29V/dec, $I_{off}$ current of 7$\times$10$^{-l4}$A at $V_{DS}$ =-0.1V and $I_{on}$ / $I_{off}$ ratio of 2.4$\times$10$^{7}$ at $V_{DS}$ =-0.1V. As a result, SLS TFT showed superior characteristics to conventional poly-Si TFTs with identical geometry.y.y.y.

A Gas Phase Kinetic Study on the Thermal Decomposition of $ClCH_2CH_2CH_2Br$

  • Kim, Sung-Hoon;Choo, Kwang-Yul;Jung, Kyung-Hoon
    • Bulletin of the Korean Chemical Society
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    • v.10 no.3
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    • pp.262-269
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    • 1989
  • The gas phase thermal decomposition of 1-bromo-3-chloropropane in the presence of radical inhibitor was studied by using the conventional static system. The mechanism of unimolecular elimination channel is shown below. [...] In this scheme, the total molecular dissociation rate constant, ($k_1\;+\;k_2$), for the decomposition of $BrCH_2CH_2CH_2Cl$ was determined by pyrolyzing the $BrCH_2CH_2CH_2Cl$ in the temperature range of $380-420^{\circ}C$ and in the pressure range of 10∼100 torr. To obtain $k_3\;and\;k_4,\;and\;to\;obtain\;k_1\;and\;k_2$ independently, the thermal decompositions of allyl chloride and allyl bromide were also studied. The Arrhenius parameters for each step are as follows; $log\;A_{\infty}\;=\;14.20(sec^{-1}),\;E_a$ = 56.10(kcal/mol) for reaction path 1; $log\;A_{\infty}\;=\;12.54(sec^{-1}),\;E_a$ = 49.75(kcal/mol) for reaction path 2; $log\;A_{\infty}\;=\;13.41(sec^{-1}),\;E_a$ = 50.04(kcal/mol) for reaction path 3; $log\;A_{\infty}\;=\;12.43(sec^{-1}),\;E_a$ = 52.78(kcal/mol) for reaction path 4; Finally, the experimentally observed pressure dependence of the rate constants in each step is compared with the theoretically predicted values that are obtained by the RRKM calculations.