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1.
UCL Open Environ ; 4: e053, 2022.
Article in English | MEDLINE | ID: mdl-37228461

ABSTRACT

This paper discusses community participation drawing on ongoing disaster recovery and preparedness projects (RPP) in the communities affected by the Heavy Rain Event of 2018 in western Japan. Participatory approaches have become a mainstream methodology for community-based disaster risk reduction (DRR) as advocated in the Sendai Framework for Disaster Risk Reduction 2015-2030. The majority of participation research addresses either 'success' factors for participation or the types of participation. The paper proposes a notion of 'widening participation' in addressing the challenge of attracting people to participate in preparedness initiatives. Originally widening participation was a higher education policy in the UK aiming to broaden the demographic composition of the student base. Even the RPP that are publicly recognised as 'good practices' struggle to recruit more people for the projects. Borrowing the notion of widening participation, the paper identifies how each project encourages non-participants to get involved in the project activities. The paper applies the EAST framework (Easy, Attractive, Social, Timely) widely utilised in the policy making of widening participation and further public services. Rather than providing the public with information and guidance, 'easy', 'attractive', 'social' and 'timely' behavioural approaches tend to enable participation. Examining these four principles in the four cases of RPP, the paper suggests that the EAST framework is feasible in strengthening the strategies for widening participation in preparedness action. The paper, however, recognises a need to address the difference between top-down public policies and bottom-up community projects in the application of the framework.

2.
Sci Adv ; 6(48)2020 11.
Article in English | MEDLINE | ID: mdl-33239290

ABSTRACT

Fibulin-4 is a matricellular protein required for extracellular matrix (ECM) assembly. Mice deficient in fibulin-4 (Fbln4-/- ) have disrupted collagen and elastin fibers and die shortly after birth from aortic and diaphragmatic rupture. The function of fibulin-4 in ECM assembly, however, remains elusive. Here, we show that fibulin-4 is required for the activity of lysyl oxidase (LOX), a copper-containing enzyme that catalyzes the covalent cross-linking of elastin and collagen. LOX produced by Fbln4-/- cells had lower activity than LOX produced by wild-type cells due to the absence of lysine tyrosyl quinone (LTQ), a unique cofactor required for LOX activity. Our studies showed that fibulin-4 is required for copper ion transfer from the copper transporter ATP7A to LOX in the trans-Golgi network (TGN), which is a necessary step for LTQ formation. These results uncover a pivotal role for fibulin-4 in the activation of LOX and, hence, in ECM assembly.


Subject(s)
Elastin , Protein-Lysine 6-Oxidase , Animals , Collagen/metabolism , Copper , Elastin/metabolism , Extracellular Matrix Proteins/genetics , Extracellular Matrix Proteins/metabolism , Mice , Protein-Lysine 6-Oxidase/genetics , Protein-Lysine 6-Oxidase/metabolism
3.
Life Sci ; 84(5-6): 132-8, 2009 Jan 30.
Article in English | MEDLINE | ID: mdl-19087881

ABSTRACT

AIMS: We previously reported that the neurotoxicity of amyloid beta protein (Abeta(1-42), 10 nM) was blocked by an Abeta-derived tripeptide, Abeta(32-34) (Ile-Gly-Leu, IGL), suggesting that IGL may be a lead compound in the design of Abeta antagonists. In the present study, three stable forms of IGL peptide with acetylation of its N-terminal and/or amidation of its C-terminal (acetyl-IGL, IGL-NH(2) and acetyl-IGL-NH(2)) were synthesized and examined for their effects on Abeta-induced neurotoxicity. MAIN METHODS: Phosphatidylinositol 4-kinase type II (PI4KII) activity was measured using recombinant human PI4KIIalpha kinase and cell viability was assessed in primary cultured hippocampal neurons. To test effects in vivo, 1.5 microl of 100 nM Abeta and/or 100 nM acetyl-IGL was injected into the hippocampal CA1 region of right hemisphere in transgenic mice expressing V337M human tau protein. Four weeks later, behavior performance in the Morris water maze was tested and after another 2 weeks, sections of brain were prepared for immunohistochemistry. KEY FINDINGS: Among the three modified tripeptides, acetyl-IGL attenuated the Abeta-induced inhibition of PI4KII activity as well as enhancement of glutamate neurotoxicity in primary cultured rat hippocampal neurons. Injection of Abeta into the hippocampus of mice impaired spatial memory and increased the number of degenerating neurons in bilateral hippocampal regions. Co-injection of acetyl-IGL prevented the learning impairment as well as the neuronal degeneration induced by Abeta. SIGNIFICANCE: These results suggest that a modified tripeptide, acetyl-IGL, may be effective in the treatment of Alzheimer's disease.


Subject(s)
Amyloid beta-Peptides/toxicity , Neurons/drug effects , Neuroprotective Agents/therapeutic use , Neurotoxicity Syndromes/prevention & control , Oligopeptides/therapeutic use , Peptide Fragments/toxicity , tau Proteins/genetics , 1-Phosphatidylinositol 4-Kinase/antagonists & inhibitors , 1-Phosphatidylinositol 4-Kinase/metabolism , Animals , Cell Survival/drug effects , Cells, Cultured , Hippocampus/drug effects , Hippocampus/enzymology , Hippocampus/pathology , Humans , Maze Learning/drug effects , Mice , Mice, Transgenic , Neurons/enzymology , Neurons/pathology , Neuroprotective Agents/pharmacology , Neurotoxicity Syndromes/etiology , Neurotoxicity Syndromes/genetics , Neurotoxicity Syndromes/pathology , Neurotoxicity Syndromes/physiopathology , Oligopeptides/administration & dosage , Oligopeptides/pharmacology , Recombinant Proteins/antagonists & inhibitors , Recombinant Proteins/metabolism
5.
Clin Endocrinol (Oxf) ; 68(1): 72-6, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17681026

ABSTRACT

OBJECTIVE: Macroprolactinaemia, mainly caused by anti-prolactin (PRL) autoantibodies, is frequently found in patients with hyperprolactinaemia. Characteristically, these patients lack clinical symptoms of hyperprolactinaemia, but the serum bioactive PRL concentrations in vitro measured by the Nb2 bioassay are usually high. In this study, we investigated the causes of the discrepancy and the true biological features of macroprolactin. SUBJECTS AND METHODS: Sixteen patients with macroprolactinaemia due to anti-PRL autoantibodies were studied. PRL bioactivity was determined by the phosphorylation of signal transducer and activator of transcription (Stat)5 in T47D human breast cancer cells and the proliferation of Nb2 rat lymphoma cells. RESULTS: PRL bioactivity by the T47D bioassay, expressed as the density of the band of phosphorylated Stat5/immunoreactive PRL, was significantly lower in sera containing anti-PRL autoantibodies (2.4 +/- 1.1) than in control sera (7.2 +/- 3.1). Dissociation of PRL from the autoantibodies by acidification resulted in an increase in phosphorylated Stat5. PRL bioactivity by the Nb2 bioassay was not significantly different between sera with and without anti-PRL autoantibodies, and free PRL in the medium gradually increased during the incubation in a time-dependent manner in sera containing anti-PRL autoantibodies. CONCLUSIONS: We conclude that the level of bioactivity of macroprolactin in the Nb2 bioassay is normal due to dissociation of PRL from the autoantibodies as a result of the longer incubation and more dilute assay conditions than in the T47D bioassay. The bioactivity of macroprolactin is low in vivo due to anti-PRL autoantibodies, but monomeric PRL dissociated from the autoantibodies retains full biological activity in patients with macroprolactinaemia.


Subject(s)
Autoantibodies/pharmacology , Prolactin/blood , Prolactin/pharmacology , Prolactinoma/blood , Prolactinoma/immunology , Adult , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Female , Humans , Immunoenzyme Techniques , Middle Aged , Phosphorylation/drug effects , Prolactin/antagonists & inhibitors , Rats , STAT5 Transcription Factor/metabolism , Young Adult
6.
Neurosci Lett ; 419(3): 247-52, 2007 Jun 04.
Article in English | MEDLINE | ID: mdl-17499922

ABSTRACT

We previously reported that the neurotoxicity of pathophysiological concentrations of amyloid beta proteins (Abetas, 0.1-10nM) as assessed by the inhibition of type II phosphatidylinositol 4-kinase (PI4KII) activity and the enhancement of glutamate toxicity was blocked by a short fragment of Abeta, Abeta(31-35). Such protective effects of shorter fragments derived from Abeta(31-35) were examined in this study to reach the shortest effective peptide, using recombinant human PI4KII and primary cultured rat hippocampal neurons. Among the peptides tested (Abeta(31-34), Abeta(31-33), Abeta(31-32), Abeta(32-35), Abeta(33-35), Abeta(34-35), Abeta(32-34), Abeta(33-34) and Abeta(32-33)), Abeta(31-34), Abeta(32-35) and Abeta(32-34) blocked both the Abeta(1-42)-induced inhibition of PI4KII activity and enhancement of glutamate toxicity on cell viability. The shortest peptide among them, Abeta(32-34), showed a dose-dependent protective effect with 50% effective concentration near 1nM, while Abeta(34-32), with a reverse amino acid sequence for Abeta(32-34), showed no protective effects. Thus, a tripeptide, Abeta(32-34) i.e. Ile-Gly-Leu, may be available as a lead compound for designing effective Abeta antagonists.


Subject(s)
1-Phosphatidylinositol 4-Kinase/drug effects , Amyloid beta-Peptides/pharmacology , Neurons/drug effects , Neuroprotective Agents/pharmacology , Peptide Fragments/pharmacology , 1-Phosphatidylinositol 4-Kinase/metabolism , Amino Acid Sequence , Animals , Cells, Cultured , Humans , Rats , Rats, Wistar , Recombinant Proteins/drug effects
7.
Life Sci ; 80(21): 1971-6, 2007 May 01.
Article in English | MEDLINE | ID: mdl-17391709

ABSTRACT

In our previous reports using primary cultured rat hippocampal neurons, pathophysiological concentrations (< or =10 nM) of amyloid beta proteins (Abetas) showed neurotoxicity via a phosphatidylinositol metabolism disorder, and soybean-derived phosphatidylinositol protected the neurons against the Abeta's neurotoxicity. In the present study, such a neurotoxic effect of Abeta and a neuroprotective effect of phosphatidylinositol were examined in vivo using transgenic mice expressing V337 M human tau. Intrahippocampal CA1 injection of 1.5 mul of 100 nM or 1 microM Abeta25-35 increased the number of degenerating neurons with an apoptotic feature in bilateral hippocampal CA1, CA2, CA3 and dentate gyrus regions in 1 month, demonstrating an in vivo neurotoxic effect of Abeta at lower concentrations after diffusion. Intrahippocampal co-injection or intracerebroventricular administration of 1.5 microl of 500 nM phosphatidylinositol prevented the Abeta25-35-induced neuronal degeneration in all the hippocampal regions, while co-injection of another acidic phospholipid, phosphatidylserine (1.5 microl, 500 nM) with Abeta25-35 showed no protective effects. Thus, exogenously applied phosphatidylinositol appeared to minimize the toxic effects of Abeta in vivo. These results suggest that soybean-derived phosphatidylinositol may be effective in the treatment of Alzheimer's disease.


Subject(s)
Amyloid beta-Peptides/toxicity , Glycine max/chemistry , Hippocampus/pathology , Neurons/drug effects , Phosphatidylinositols/pharmacology , tau Proteins/genetics , Analysis of Variance , Animals , Hippocampus/drug effects , In Situ Nick-End Labeling , Mice , Mice, Transgenic , Mutation/genetics
8.
Endocrinology ; 148(5): 2465-70, 2007 May.
Article in English | MEDLINE | ID: mdl-17303669

ABSTRACT

Macroprolactinemia is hyperprolactinemia in humans mainly due to anti-PRL (prolactin) autoantibodies and is a pitfall for the differential diagnosis of hyperprolactinemia. Despite its high prevalence, the pathogenesis remains unclear. In this study, we examined whether anti-PRL autoantibodies develop via immunization with homologous rat pituitary PRL in rats to elucidate what mechanisms are involved and whether they cause hyperprolactinemia with low PRL bioactivity, as seen in human macroprolactinemia. Anti-PRL antibodies were developed in 19 of 20 rats immunized with homologous rat pituitary PRL and 29 of 30 rats with heterogeneous bovine or porcine pituitary PRL but did not develop in 25 control rats. In rats with anti-PRL antibodies, the basal serum PRL levels were elevated, and a provocative test for PRL secretion using dopamine D2 receptor antagonist (metoclopramide) showed a normal rising response with a slower clearance of PRL because of the accumulation of macroprolactin in blood. Antibodies developed by porcine or rat pituitary PRL reduced the bioactivity of rat serum PRL, and gonadal functions in these rats were normal despite hyperprolactinemia. Anti-PRL antibodies were stable and persisted for at least 5 wk after the final injection of PRL. These findings suggest that pituitary PRL, even if homologous, has antigenicity, leading to the development of anti-PRL autoantibodies. We successfully produced an animal model of human macroprolactinemia, with which we can explain the mechanisms of its clinical characteristics, i.e. asymptomatic hyperprolactinemia.


Subject(s)
Autoantibodies/blood , Autoantibodies/immunology , Hyperprolactinemia/immunology , Prolactin/blood , Prolactin/immunology , Animals , Disease Models, Animal , Dopamine Antagonists/pharmacology , Epitopes , Estrous Cycle/physiology , Female , Hyperprolactinemia/drug therapy , Immunization , Male , Metoclopramide/pharmacology , Rats , Testosterone/blood
9.
Brain Res ; 1130(1): 235-8, 2007 Jan 26.
Article in English | MEDLINE | ID: mdl-17169336

ABSTRACT

To test whether the increased intracellular Cl- concentration ([Cl-]i) is responsible for the enhanced glutamate toxicity, antisense oligonucleotide of ClP55, a Cl- -ATPase/pump associated protein, was transfected in cultured rat hippocampal neurons. Neuronal [Cl-]i in the antisense oligonucleotide-transfected culture increased to a level 3- to 4-fold higher than that in control. Glutamate exposure (10 microM, 10 min) increased neuronal apoptosis and decreased Akt-pS473 level in the antisense oligonucleotide-transfected neurons, but not in control or sense oligonucleotide-transfected ones, suggesting the responsibility of elevated [Cl-]i in the enhancement of glutamate neurotoxicity.


Subject(s)
Chlorides/metabolism , Glutamic Acid/toxicity , Hippocampus/enzymology , Ion Pumps/metabolism , Neurons/enzymology , Adenosine Triphosphatases/metabolism , Animals , Anion Transport Proteins/metabolism , Apoptosis/drug effects , Carbon-Sulfur Lyases/metabolism , Cells, Cultured , Down-Regulation , Hippocampus/cytology , Hippocampus/drug effects , Neurons/drug effects , Neurotoxins/toxicity , Oligonucleotides, Antisense/metabolism , Protein Subunits , Rats , Rats, Wistar
10.
Neurosci Lett ; 399(1-2): 175-80, 2006 May 15.
Article in English | MEDLINE | ID: mdl-16497436

ABSTRACT

In our previous studies, pathophysiological concentrations of amyloid-beta (Abeta) proteins increased intracellular Cl(-) concentration ([Cl(-)]i) and enhanced glutamate neurotoxicity in primary cultured neurons, suggesting Cl(-)-dependent changes in glutamate signaling. To test this possibility, we examined the effects of isethionate-replaced low Cl(-) medium on the Abeta-induced enhancement of glutamate neurotoxicity in the primary cultured rat hippocampal neurons. In a normal Cl(-) (135 mM) medium, treatment with 10 nM Abeta25-35 for 2 days increased neuronal [Cl(-)]i to a level three times higher than that of control as assayed using a Cl(-)-sensitive fluorescent dye, while in a low Cl(-) (16 mM) medium such an Abeta25-35-induced increase in [Cl(-)]i was not observed. The Abeta treatment aggravated glutamate neurotoxicity in a normal Cl(-) medium as measured by mitochondrial reducing activity and lactate dehydrogenase (LDH) release, while in a low Cl(-) medium the Abeta treatment did not enhance glutamate toxicity. Upon such Abeta plus glutamate treatment under a normal Cl(-) condition, activated anti-apoptotic molecule Akt (Akt-pS473) level monitored by Western blot significantly decreased to 74% of control. Under a low Cl(-) condition, a resting Akt-pS473 level was higher than that under a normal Cl(-) condition and did not significantly change upon Abeta plus glutamate treatment. Tyrosine phosphorylation levels of 110 and 60 kDa proteins (pp110 and pp60) increased upon Abeta plus glutamate treatment under a normal Cl(-), but not low Cl(-), condition. These findings indicated that Abeta-induced enhancement of glutamate neurotoxicity is Cl(-)-dependent. Chloride-sensitive Akt pathway and tyrosine phosphorylation of proteins (pp110 and pp60) may be involved in this process.


Subject(s)
Amyloid beta-Peptides/physiology , Chlorides/metabolism , Glutamic Acid/physiology , Hippocampus/metabolism , Neurons/metabolism , Peptide Fragments/physiology , Amyloid beta-Peptides/toxicity , Animals , Apoptosis , Cells, Cultured , Embryo, Mammalian/cytology , Glutamic Acid/toxicity , Hippocampus/cytology , Intracellular Space/metabolism , L-Lactate Dehydrogenase/metabolism , Mitochondria/metabolism , Neurons/drug effects , Peptide Fragments/toxicity , Phosphatidylinositol 3-Kinases/metabolism , Phosphorylation , Proto-Oncogene Proteins c-akt/metabolism , Proto-Oncogene Proteins pp60(c-src)/metabolism , Rats , Rats, Wistar , Tyrosine/metabolism
11.
Neurosci Lett ; 396(2): 148-52, 2006 Mar 27.
Article in English | MEDLINE | ID: mdl-16356635

ABSTRACT

We previously reported that pathophysiological concentrations of amyloid beta protein (Abeta25-35, 0.1-10 nM) directly inhibited type II phosphatidylinositol 4-kinase (PI4KII) activity in neuronal plasma membranes, which resulted in the enhanced glutamate neurotoxicity. In the present study, we examined the effects of Abeta fragments, Abeta20-29 and Abeta31-35, on the 10 nM Abeta25-35- or Abeta1-42-induced inhibition of PI4KII activity. Both of the peptide fragments recovered the inhibition of rat brain plasma membrane PI4KII activity over the concentration range of 0.1-5 nM. Such protection by the Abeta fragments was observed in the 10 nM Abeta25-35-induced inhibition of recombinant human PI4KII, suggesting that these Abeta fragments blocked the inhibition on PI4KII molecule. The Abeta25-35-induced enhancement of glutamate neurotoxicity was also completely inhibited in the presence of these fragments. Thus, Abeta20-29 and Abeta31-35 ameliorated the Abeta-enhanced glutamate neurotoxicity probably through attenuation of Abeta-induced inhibition of PI4KII activity.


Subject(s)
Amyloid beta-Peptides/administration & dosage , Neurons/enzymology , Peptide Fragments/administration & dosage , Phosphotransferases (Alcohol Group Acceptor)/antagonists & inhibitors , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Animals , Cells, Cultured , Dose-Response Relationship, Drug , Enzyme Activation/drug effects , Hippocampus/drug effects , Hippocampus/enzymology , Minor Histocompatibility Antigens , Neurons/drug effects , Rats , Rats, Wistar
12.
Neurosci Lett ; 384(1-2): 44-7, 2005.
Article in English | MEDLINE | ID: mdl-15899548

ABSTRACT

The effects of anxiolytic honokiol derivative, dihydrohonokiol-B (DHH-B), on amyloid beta protein (Abeta(25-35), 10 nM)-induced changes in Cl(-)-ATPase activity, intracellular Cl- concentration ([Cl-]i) and glutamate neurotoxicity were examined in cultured rat hippocampal neurons. DHH-B (10 ng/ml) recovered Abeta-induced decrease in neuronal Cl(-)-ATPase activity without any changes in the activities of Na+/K+-ATPase and anion-insensitive Mg2+-ATPase. A GABA(C) receptor antagonist (1,2,5,6,-tetrahydropyridin-4-yl) methyl-phosphinic acid (TPMPA, 15 microM), inhibited the protective effects of DHH-B on Cl(-)-ATPase activity. DHH-B reduced Abeta-induced elevation of [Cl-]i as assayed using a Cl(-)-sensitive fluorescent dye, and prevented Abeta-induced aggravation of glutamate neurotoxicity. These data suggest that DHH-B exerts the neuroprotective action against Abeta through GABA(C) receptor stimulation.


Subject(s)
Amyloid beta-Peptides/toxicity , Anti-Anxiety Agents/pharmacology , Biphenyl Compounds/pharmacology , Hippocampus/cytology , Neurons/drug effects , Adenosine Triphosphatases/metabolism , Amyloid beta-Peptides/antagonists & inhibitors , Animals , Anion Transport Proteins , Ca(2+) Mg(2+)-ATPase/metabolism , Cell Survival/drug effects , Cells, Cultured , Chlorides/metabolism , Drug Interactions , Embryo, Mammalian , Glutamic Acid/toxicity , Lactate Dehydrogenases/metabolism , Rats , Rats, Sprague-Dawley , Sodium-Potassium-Exchanging ATPase/metabolism , Tetrazolium Salts/metabolism
13.
J Clin Endocrinol Metab ; 90(5): 3036-44, 2005 May.
Article in English | MEDLINE | ID: mdl-15687336

ABSTRACT

Although macroprolactinemia due to antiprolactin (anti-PRL) autoantibodies is not uncommon among hyperprolactinemic patients, the pathogenesis of such macroprolactinemia is still unknown. We examined IgG subclasses of anti-PRL autoantibodies by enzyme immunoassay, and PRL phosphorylation and isoforms by Western blotting, mass spectrometry, and two-dimensional electrophoresis in six patients with anti-PRL autoantibodies and in 29 controls. PRL-specific IgG subclasses in patients with anti-PRL autoantibodies were heterogeneous, but five of six patients showed IgG4 predominance, which is known to be produced by chronic antigen stimulation. Western blot and mass spectrometric analyses revealed that human pituitary PRL was phosphorylated at serine 194 and serine 163, whereas serine 163 in serum PRL was dephosphorylated. On two-dimensional electrophoresis, serum PRL mainly consisted of isoform with isoelectric point (pI) 6.58 in control hyperprolactinemic patients, whereas acidic isoforms (pIs 6.43 and 6.29) were also observed in patients with anti-PRL autoantibodies. Our data first demonstrate that human pituitary PRL is serine phosphorylated and partially dephosphorylated in serum, and suggest that the acidic isoforms may give rise to chronic antigen stimulation in patients with anti-PRL autoantibodies.


Subject(s)
Autoantibodies/blood , Prolactin/blood , Prolactin/immunology , Adult , Amino Acid Sequence , Blotting, Western , Female , Humans , Middle Aged , Molecular Sequence Data , Phosphorylation , Protein Isoforms , Serine/metabolism , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
14.
J Neurochem ; 91(5): 1164-70, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15569259

ABSTRACT

We previously found that pathophysiological concentrations (< or = 10 nm) of an amyloid beta protein (Abeta25-35) reduced the plasma membrane phosphatidylinositol monophosphate level in cultured rat hippocampal neurons with a decrease in phosphatidylinositol 4-monophosphate-dependent Cl- -ATPase activity. As this suggested an inhibitory effect of Abeta25-35 on plasma membrane phosphatidylinositol 4-kinase (PI4K) activity, in vitro effects of Abetas on PI4K activity was examined using rat brain subcellular fractions and recombinant human type II PI4K (PI4KII). Abeta25-35 (10 nm) inhibited PI4KII activity, but neither PI 3-kinase (PI3K) nor type III PI4K (PI4KIII) activity, in microsomal fractions, while 100 nm Abeta25-35 inhibited PI3K activity in mitochondrial fractions. In plasma membrane-rich fractions, Abetas (> 0.5 nm) dose-dependently inhibited PI4KII activity, the maximal inhibition to 77-87% of control being reached around 10 nm of Abetas without significant changes in apparent Km values for ATP and PI, suggesting non-competitive inhibition by Abetas. The inhibition by 10 nm Abeta25-35 was reversible. In recombinant human PI4KIIalpha, inhibition profiles of Abetas were similar to those in rat brain plasma membranes. Therefore, pathophysiological concentrations of Abetas directly and reversibly inhibited plasma membrane PI4KII activity, suggesting that plasma membrane PI4KII is a target of Abetas in the pathogenesis of Alzheimer's disease.


Subject(s)
1-Phosphatidylinositol 4-Kinase/antagonists & inhibitors , Amyloid beta-Peptides/pharmacology , Brain/drug effects , 1-Phosphatidylinositol 4-Kinase/metabolism , Adenosine/pharmacology , Adenosine Triphosphate/pharmacology , Androstadienes/pharmacology , Animals , Brain/cytology , Cell Membrane/drug effects , Cell Membrane/enzymology , Dose-Response Relationship, Drug , Drug Interactions , Enzyme Activation/drug effects , Enzyme Inhibitors/pharmacology , Humans , Male , Mutagenesis/physiology , Peptide Fragments/pharmacology , Rats , Rats, Wistar , Recombinant Proteins/antagonists & inhibitors , Subcellular Fractions/drug effects , Wortmannin
15.
Neurosci Lett ; 367(2): 156-9, 2004 Sep 02.
Article in English | MEDLINE | ID: mdl-15331142

ABSTRACT

Long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen reportedly decrease a risk for the progression of Alzheimer's disease (AD), whose mechanisms are still controversial. We previously reported that pathophysiological concentrations (1-10 nM) of amyloid beta proteins (Abetas) increased intracellular Cl- concentration ([Cl-]i) and aggravated glutamate neurotoxicity in the rat brain neuronal culture. In this study, we examined the effects of therapeutic concentrations of ibuprofen and other drugs with cyclo-oxygenase (COX)-1 and/or COX-2 inhibiting activities on 10 nM Abeta25-35-induced changes in cultured rat hippocampal neurons. Ibuprofen (10-100 microM) dose-dependently inhibited the Abeta25-35-induced increase in [Cl-]i in pyramidal cell-like neurons. Not only ibuprofen, aspirin (100 microM), indomethacin (50 microM), and selective COX-1 or COX-2 inhibitor (10 nM ketrolac or 2 microM NS398) also blocked the Abeta-induced increase in neuronal [Cl-]i, though such effects of COX-2 preferring drugs were limited in aggregated Abeta-induced changes. Further, ibuprofen as well as selective COX-1 or COX-2 inhibitor reduced Abeta-induced aggravation of glutamate toxicity as assessed by cell viability. These findings suggest that NSAIDs protect neurons from Abeta-induced degeneration via inhibition of neuronal COX-1 as well as COX-2.


Subject(s)
Amyloid beta-Peptides/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Chlorides/metabolism , Hippocampus/cytology , Intracellular Space/drug effects , Neurons/drug effects , Analysis of Variance , Animals , Animals, Newborn , Cell Survival/drug effects , Cells, Cultured , Cyclooxygenase Inhibitors/pharmacology , Dose-Response Relationship, Drug , Drug Interactions , Glutamic Acid/toxicity , Hippocampus/drug effects , Inhibitory Concentration 50 , Neurons/metabolism , Quinolinium Compounds , Rats , Rats, Wistar
16.
Eur J Pharmacol ; 488(1-3): 27-34, 2004 Mar 19.
Article in English | MEDLINE | ID: mdl-15044032

ABSTRACT

The existence of Cl(-) channels in lymphocytes and neutrophils has been increasingly recognized, but the biological functions are not yet clear. We examined the effects of Cl(-) channel blockers on the cell proliferation and the cell cycle of human leukemic cell lines. The growth of leukemic cells was suppressed most efficiently by NPPB (5-nitro-2-(3-phenylpropylamino) benzoic acid), partially by 9-AC (9-anthracenecarboxylic acid) and tamoxifen, but not by stilbene compounds. NPPB increased the G0/G1 population and induced the expression of p21, one of the critical molecules for G1/S checkpoint. Antisense oligonucleotide for a NPPB-sensitive and stilbene-insensitive Cl(-) channel, ClC-2, sufficiently suppressed the ClC-2 protein synthesis, but did not affect the growth of leukemic cells. These findings suggest that NPPB-sensitive and stilbene-insensitive Cl(-) channels other than ClC-2 play important roles in cell cycles and cell proliferation of human leukemic cells.


Subject(s)
Chloride Channels/antagonists & inhibitors , Leukemia/metabolism , Oncogene Protein p21(ras)/biosynthesis , Blotting, Northern , Blotting, Western , CLC-2 Chloride Channels , Cell Cycle/drug effects , Cell Division/drug effects , Chloride Channels/drug effects , Chloride Channels/metabolism , Flow Cytometry , HL-60 Cells , Humans , Jurkat Cells , Nitrobenzoates/pharmacology , Oligonucleotides, Antisense/pharmacology , RNA/biosynthesis , Transfection , Tumor Cells, Cultured
17.
Brain Res Mol Brain Res ; 123(1-2): 1-6, 2004 Apr 07.
Article in English | MEDLINE | ID: mdl-15046860

ABSTRACT

Although gamma-aminobutyric acid (GABA)C receptor rho1, rho2 and rho3 subunits are reportedly expressed in pyramidal and granule cells in the hippocampus at various developmental stages, it is not clear whether these three rho subunits are coexpressed in a single neuron. To attempt to answer this question, we performed single-cell RT-PCR for rho subunits from neurons of rat brain hippocampus. In hippocampal cultures, pyramidal cells were positive for rho1 mRNA expression in 89%, rho2 in 94% and rho3 in 94%, while granule cells were positive for rho1 mRNA in only 6%, rho2 in 36% and rho3 in 91%. Intensive amplification of the RT-PCR products by the second PCR revealed that all the three rho subunits were coexpressed in a single pyramidal and granule cells from both of the cultures and the slices. These results suggest that all the three GABAC receptor rho1, rho2 and rho3 subunits are present probably in different compositions in pyramidal and granule cells in the rat hippocampus.


Subject(s)
Hippocampus/metabolism , Neural Pathways/metabolism , Neurons/metabolism , Pyramidal Cells/metabolism , Receptors, GABA/genetics , Animals , Cells, Cultured , Hippocampus/cytology , In Vitro Techniques , Neural Pathways/cytology , Neurons/cytology , Protein Subunits/genetics , Pyramidal Cells/cytology , RNA, Messenger/metabolism , Rats , Reverse Transcriptase Polymerase Chain Reaction
18.
Biochem Biophys Res Commun ; 317(1): 192-7, 2004 Apr 23.
Article in English | MEDLINE | ID: mdl-15047167

ABSTRACT

ClC-5 is a chloride channel known to be expressed in the kidney. We previously reported that ClC-5 mRNA was also strongly expressed in immature human myeloid cell line (HL-60), but weakly expressed in mature neutrophils. To clarify the underlying mechanisms, we examined the relationship between ClC-5 expression and cell cycle. Dimethyl sulfoxide treatment of HL-60 that causes differentiation with G0/G1 cell cycle arrest decreased the expression of ClC-5 mRNA. Cell sorting and synchronization experiments revealed that ClC-5 mRNA expression was high in S and G2/M phases and low in G0/G1 phase. ClC-5 antisense oligonucleotide suppressed proliferation of HL-60 cells with a decrease in ClC-5 protein expression, probably due to G2 arrest. These results suggest that cell cycle-dependent expression of ClC-5 has a role in cell cycle progression in myeloid cells.


Subject(s)
Chloride Channels/metabolism , Myeloid Cells/cytology , Myeloid Cells/metabolism , Cell Cycle/drug effects , Cell Cycle/physiology , Cell Differentiation , Chloride Channels/biosynthesis , Chloride Channels/genetics , DNA/analysis , Dimethyl Sulfoxide/pharmacology , Gene Expression/drug effects , HL-60 Cells , Humans , Interphase , Neutrophils/metabolism , Oligonucleotides, Antisense/pharmacology , RNA, Messenger/biosynthesis
19.
Neurosci Lett ; 350(2): 105-8, 2003 Oct 23.
Article in English | MEDLINE | ID: mdl-12972164

ABSTRACT

Effects of soybean-derived phosphatidylinositol (PI) on amyloid beta protein (10 nM Abeta(25-35))-induced changes in Cl(-)-ATPase activity, intracellular Cl- concentration ([Cl-]i) and glutamate neurotoxicity were examined using cultured rat hippocampal neurons. Soybean-derived PI (> or =5 nM) dose-dependently recovered Abeta-induced decrease in neuronal Cl(-)-ATPase activity without any changes in the activities of Na+,K(+)-ATPase and anion-insensitive Mg(2+)-ATPase. Soybean-derived PI reduced Abeta-induced elevation of [Cl-](i) as assayed using a Cl(-)-sensitive fluorescent dye, and prevented Abeta-induced aggravation of glutamate neurotoxicity assayed by mitochondrial 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt reducing activity and plasma membrane lactate dehydrogenase release. These data suggest that soybean-derived PI may be useful as a therapeutic and/or preventive strategy for Alzheimer's disease.


Subject(s)
Amyloid beta-Peptides/toxicity , Glycine max , Hippocampus/drug effects , Neurons/drug effects , Phosphatidylinositols/pharmacology , Adenosine Triphosphatases/antagonists & inhibitors , Adenosine Triphosphatases/metabolism , Animals , Cell Survival/drug effects , Cell Survival/physiology , Cells, Cultured , Dose-Response Relationship, Drug , Hippocampus/metabolism , Neurons/metabolism , Rats , Rats, Wistar
20.
Amyloid ; 10(4): 207-14, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14986479

ABSTRACT

In mice, apolipoprotein A-II (apoA-II) associates to form amyloid fibrils in an age-associated manner. We determined the complete nucleotide sequences of the apoA-II gene (Apoa2) cDNA in 41 inbred strains of mice including Mus musculus domesticus (laboratory mouse), Mus musculus castaneus, Mus musculus molossinus, Mus musculus musculus and Mus spretus. Among these strains we identified 7 alleles (Apoa2a1, Apoa2a2, Apoa2b, Apoa2c, Apoa2d, Apoa2e and Apoa2f). Polymorphisms of nucleotides at 15 positions were detected and amino acid substitutions were found at 8 positions. Apoa2a1 was found in all mouse subspecies, but Apoa2b and Apoa2c were found only in Mus musculus domesticus. Two strains of Mus spretus have the unique alleles Apoa2e and Apoa2f which resemble Apoa2c. We confirmed that VICS in which we found severe amyloidosis here and other amyloidoneic strains in published reports have Apoa2c allele. We determined the plasma concentrations of total and HDL cholesterol in the strains of Mus musculus domesticus with the Apoa2a1, Apoa2b and Apoa2c alleles. Significantly higher concentrations of plasma cholesterol were observed in mouse strains with the Apoa2b allele. These findings provide fundamental data on mouse Apoa2 alleles. Furthermore, differences in these alleles likely have considerable influence on traits related to amyloidosis and lipid metabolism.


Subject(s)
Amyloidosis/genetics , Apolipoprotein A-II/genetics , Polymorphism, Genetic/genetics , Alleles , Animals , Apolipoprotein A-II/blood , Cholesterol, HDL/blood , Male , Mice , Mice, Inbred Strains
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