• Title/Summary/Keyword: transmembrane

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Apoptosis Induction in Human Leukemic Promyelocytic HL-60 and Monocytic U937 Cell Lines by Goniothalamin

  • Petsophonsakul, Ploingarm;Pompimon, Wilart;Banjerdpongchai, Ratana
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.2885-2889
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    • 2013
  • Goniothalamin is an active compound extracted from Goniothalamus griffithii, a local plant found in northern Thailand. Goniothalamin inhibits cancer cell growth but is also toxic to normal cells. The aims of this study were to identify the cytotoxic effect of goniothalamin and the mechanism of cell death in human HL-60 and U937 cells. Cytotoxicity was determined by MTT assay and cell cycle profiles were demonstrated by staining with propidium iodide (PI) and flow cytometry. Apoptosis was confirmed by staining with annexin V-FITC/propidium iodide (PI) and flow cytometry. Reduction of mitochondrial transmembrane potential was determined by staining with dihexyloxacarbocyanine iodide and flow cytometry and expression of Smac, caspase-8 and -9 was demonstrated by Western blotting. Goniothalamin inhibited growth of HL-60 and U937 cell lines. An increase of SubG1 phase was found in their cell cycle profiles, indicating apoptosis as the mode of cell death. Apoptosis was confirmed by the flip-flop of phosphatidylserine using annexin V-FITC/PI assay in HL60 and U937 cells in a dose response manner. Furthermore, reduction of mitochondrial transmembrane potential was found in both cell types while expression of caspase-8, -9 and Smac/Diablo was increased in HL-60 cells. Taken together, our results indicate that goniothalamin-treated human leukemic cells undergo apoptosis via intrinsic and extrinsic pathways.

Molecular Characterization and Expression Pattern of Na+-K+-2Cl- Cotransporter 2 (NKCC2) in the Intestine of Starry Flounder Platichthys stellatus after Bacterial Challenge

  • Kim, Yi Kyung;Nam, Yoon Kwon
    • Fisheries and Aquatic Sciences
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    • v.18 no.2
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    • pp.173-181
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    • 2015
  • We identified the $Na^+-K^+-2Cl^-$ cotransporter 2 (NKCC2) cDNA isoform from starry flounder, Platichthys stellate. The NKCC2 cDNA encoded a polypeptide of 1,043 amino acids representing 12 putative transmembrane domains based on the bioinformatic topology prediction. In addition, starry flounder NKCC2 possessed highly conserved residues within transmembrane domain 4, known as an essential site for its function. End-point reverse transcription-polymerase chain reaction analysis revealed that the NKCC2 transcript was moderately expressed only in the anterior and posterior intestines and the rectum. The NKCC2 mRNA level in the rectum, but not in other segments, was significantly induced 3 days post Streptococcus parauberis challenge, indicating that excess salt may be transported into the rectum. Taken together, our data indicate that an S. parauberis infection could tip the intestinal fluid balance in favor of fluid accumulation, indicating that bacterial pathogens can interfere with intestinal osmotic balance and normal mucosal immune homeostasis.

Introduction of tmie Gene Can Recover the Hearing Impairment and Abnormal Behavior in the Circling Mouse

  • Shin, Mi-Jung;Park, Seo-Jin;Pare, Hum Dai;Ryoo, Zae-Young
    • Reproductive and Developmental Biology
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    • v.34 no.2
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    • pp.63-71
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    • 2010
  • The spontaneous mutant circling mouse (cir/cir) shows a circling behavior and hearing loss. We produced transgenic mice overexpressing transmembrane inner ear (tmie) gene, the causative gene, for the phenotypic rescue of the circling mouse. Through the continuous breeding with circling mice, the cir/cir homozygous mice carrying the transgene (cir/cir-tg) were produced. The rescued cir/cir-tg mice were able to swim in the water with proper orientation and did not show any circling behavior like wild type mice. Western blot and immunohistochemical analysis exhibited that the transgenic tmie was expressed in the inner ear. Inner and outer hair cells were recovered in the cochlea and spiral ganglion neurons were also recovered in the rescued mice. Auditory brainstem response (ABR) test demonstrated that the cir/cir-tg mice are able to respond to sound. This study demonstrates that tmie transgene can recover the hearing impairment and abnormal behavior in the circling mouse.

Effect of Glycyrrhetinic acid on the Cell Death of Transplanted-Ll2lO cells in Mice (글리실레틴산이 생쥐에 이식된 L1210 세포의 세포사에 미치는 영향)

  • Eun, Jae-Soon;Kwon, Jin;Yum, Jung-Yul;Oh, Chan-Ho
    • YAKHAK HOEJI
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    • v.42 no.6
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    • pp.583-588
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    • 1998
  • These experiments were investigated effects of the cell death of glycyrrhetinic acid (GA) on transplanted-L1210 cells in BALB/c mice. The GA suppressed the proliferation of L121 0 cells in vivo and in vitro system. The administration of GA induced apoptosis of transplanted-L1210 cells via the reduction of mitochondrial transmembrane potential in mice. The GA enhanced the production of nitric oxidation in peritoneal macrophages obtained from L1210 cells-transplanted mice. The apoptosis of L1210 cells were induced by co-culture of the macrophages obtained from GA administered mice and L1210 cells in vitro, and was partly inhibited by the treatment of L-NMMA. These results suggest that GA induces the cytotoxicity and the apoptosis of transplanted-L1210 cells via the production of nitric oxide in peritoneal macrophages.

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Biochemical and Biophysical Characterizations of the Interaction between Two PDZ Adapter Proteins NHERF and E3KARP in vitro

  • Hwang, Eun-Young;Jeong, Mi-Suk;Jang, Se-Bok
    • Bulletin of the Korean Chemical Society
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    • v.31 no.11
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    • pp.3241-3246
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    • 2010
  • NHERF ($Na^+/H^+$ exchanger regulatory factor) and E3KARP (NHE3 kinase A regulatory protein) play important roles in membrane targeting, trafficking and sorting of ion channels, transmembrane receptors and signaling proteins in many tissues. Each of these proteins contains two PDZ (PSD-95/Dlg-1/ZO-1) domains, which mediate the assembly of transmembrane and cytosolic proteins into functional signal transduction complexes. The interaction between NHERF and E3KARP was investigated by surface plasmon resonance spectroscopy (BIAcore), fluorescence measurement, His-tagged pull-down experiment, and size-exclusion column (SEC) chromatography. BIAcore experiments revealed that NHERF bound to E3KARP with an apparent $K_D$ of 7 nM. Fluorescence emission spectra of the NHERF-E3KARP complex suggested that the tight interaction between these proteins was accompanied by significant conformational changes in one or both. The CD spectra of NHERF and E3KARP show that the conformational changes of these proteins were dependent on pH and temperature. These results implicate that the NHERF-E3KARP complex allows intracellular signaling complexes to form through PDZ-PDZ interactions.

Cell Surface Expression of Tumor Necrosis Factor-Alpha by Activated Rat Astrocytes

  • Chung, Il-Yup;Benveniste, Etty N.
    • BMB Reports
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    • v.29 no.6
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    • pp.530-534
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    • 1996
  • Astrocyte are the major glial cell type in the central nervous system (CNS), and analogous to macrophage, mediates the number of immune responses such as production of cytokines including tumor necrosis factor alpha ($TNF-{\alpha}$) upon activation. $TNF-{\alpha}$ has been implicated in neuroimmunological disorders through killing oligodendrocytes and thus causing demyelination. It has been previously demonstrated that mitogen-activated T cells synthesized a 26 kDa precursor form of $TNF-{\alpha}$ which is bound to the surface of a membrane, and is later secreted as a 17 kDa mature version. In order to examine whether astrocytes would produce the transmembrane form of $TNF-{\alpha}$, astrocytes were stimulated with biological stimuli and the membrane form of $TNF-{\alpha}$ was analyzed by Western blot and FACS analysis. When astrocytes are stimulated with lipopolysaccharide (LPS), $IFN-{\gamma}/LPS$, or $IFN-{\gamma}/IL-1{\beta}$, they were able to express a membrane-anchored $TNF-{\alpha}$ of approximately 26 kDa protein which was immunoreactive to an $anti-TNF-{\alpha}$ antibody, whereas unstimulated astrocytes or astrocytes treated with $IFN-{\gamma}$ or $IL-1{\beta}$ alone was not. Our FACS data were also consistent with the immunoblot analysis. Our result suggests that the membrane form of $TNF-{\alpha}$ expressed by activated astrocytes may cause local damage to oligodendrocytes by direct cell-cell contact and contribute to demyelination observed in multiple sclerosis (MS) and experimental allergic encephalomyelitis (EAE).

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Cadmium and zinc removal from water by polyelectrolyte enhanced ultrafiltration

  • Ennigrou, Dorra Jellouli;Ali, Mourad Ben Sik;Dhahbi, Mahmoud;Mokhtar, Ferid
    • Membrane and Water Treatment
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    • v.5 no.3
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    • pp.183-195
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    • 2014
  • The efficiency of two metal ions (cadmium, zinc) removal from aqueous solutions by ultrafiltration (UF) and Polymer Enhanced Ultrafiltration (PEUF) processes were investigated in this work. The UF and PEUF studies were carried out using an ultrafiltration tangential cell system equipped with 5.000 MWCO regenerated cellulose. A water-soluble polymer: the polyacrylic acid (PAA) was used as complexant for PEUF experiments. The effects of transmembrane pressure, pH, metal ions and loading ratio on permeate fluxes and metal ions removals were evaluated. In UF process, permeate fluxes increase linearly with increasing pH for different transmembrane pressure, which may be the consequence of the formation of soluble metal hydroxyl complexes in the aqueous phase. In PEUF process, above pH 5.0, the Cd(II) retention reaches a plateau at 90% and Zn(II) at 80% for L = 5. Also, cadmium retention at different L is greater than zinc retention at pH varying from 5.0 to 9.0. In a mixture solution, cadmium retention is higher than zinc for different loading ratio, this is due to interactions between carboxylic groups of PAA and metal ions and more important with cadmium ions.

Dynamic Characteristics for the Separation of Inulin Solution in Membrane Filtrsition System of Tangential Flow (접선류 막분리 시스템에 의한 이눌린 수용액의 분리 동특성)

  • 허병기;배천순이기정목영일
    • KSBB Journal
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    • v.5 no.1
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    • pp.69-74
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    • 1990
  • Dynamic characteristics of separation in membrane filtration system of tangential flow was investigated to find the functional relationship among the filtrate flux, transmembrane pressure, inulin concentration and recirculation rate. In case that NMWL is 1000, tracts-membrane pressure $0.4kgf/\;{\textrm{cm}^2}$ to $3.2kgf/\;{\textrm{cm}^2}$, inulin concentration lwt% to 5wt%, and recirculation rate 4ml / sec, mathematical model for the function among filtrate flux, transmembrane pressure, and inulin concentration was deduced and expressed as follows.Jv = (0.0022p + 0.0003) ln \frac{3p\;+\;2.1}{C_b}$ The values calculated by the above equation and those measured were compared to find to be nicely in accord with each other. Especially the agreement was enhanced in the region of higher concentration of inulin.

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The Effect of the Making Methods of Hollow Fiber Active Layer on Performance for Nanofiltration Helical Module (Nanofiltration Helical Module에서 Hollow Fiber Active Layer의 성형법에 따른 성능변화에 관한 연구)

  • ;Belfort, Georges
    • Membrane Journal
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    • v.7 no.2
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    • pp.95-109
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    • 1997
  • The effects of varing axial flow rate and solute concentration on the performance of both module sets made by different methods for active layer formation were compared and determined. All experiments were conducted simultaneously at the same transmembrane pressure and energy consumption per membrane area. In every comparative run between the presence of Dean vortices in a helical module and absence of such vortices in a linear module from the first module set, the solution fluxes and permeabilities were higher, and in some cases substantially higher for the vortex flow. With pure water, the permeabilities of both modules from the second module set were different and the flux in a linear module was 150% higher than in the helical module. This explained both module membranes were totally different.

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Application of a Membrane Bioreactor in Denitrification of Explosives Hydrolysates (Membrane Bioreactor를 이용한 폭발성 물질의 가수분해 부산물의 탈질과정에의 적용)

  • Zoh, Kyung-Duk
    • Journal of Korean Society on Water Environment
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    • v.18 no.2
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    • pp.113-122
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    • 2002
  • A bench-scale anoxic membrane bioreactor (MBR) system, consisting of a bioreactor coupled to a ceramic crossflow ultrafiltration module, was evaluated to treat a synthetic wastewater containing alkaline hydrolysis byproducts (hydrolysates) of RDX, The wastewater was formulated the same as RDX hydrolysates, and consisted of acetate, formate, formaldehyde as carbon sources and nitrite, nitrate as electron accepters. The MBR system removed 80 to 90% of these carbon sources, and approximately 90% of the stoichiometric amount of nitrate, 60% of nitrite. The reactor was also operated over a range of transmembrane pressures, temperatures, suspended solids concentration, and organic loading rate in order to maximize treatment efficiency and permeate flux. Increasing transmembrane pressure and temperature did not improve membrane flux significantly. Increasing biomass concentration in the bioreactor decreased the permeate flux significantly. The maximum volumetric organic loading rate was $0.72kg\;COD/m^3/day$, and the maximum F/M ratio was 0.50 kg N/kg MLSS/day and 1.82 kg COD/kg MLSS/day. Membrane permeate was clear and essentially free of bacteria, as indicated by heterotrophic plate count. Permeate flux ranged between 0.15 and $2.0m^3/m^2/day$ and was maintained by routine backwashing every 3 to 4 day. Backwashing with 2% NaOCl solution every fourth or fifth backwashing cycle was able to restore membrane flux to its original value.