Molecular evidence for a glycine-gated chloride channel in macrophages and leukocytes

2002 ◽  
Vol 283 (4) ◽  
pp. G856-G863 ◽  
Author(s):  
Matthias Froh ◽  
Ronald G. Thurman ◽  
Michael D. Wheeler
Keyword(s):  
Spinal Cord ◽  
Kupffer Cells ◽  
Chloride Channel ◽  
Glycine Receptor ◽  
Molecular Evidence ◽  
Dependent Manner ◽  
Neuronal Tissues ◽  
The Central Nervous System ◽  
Receptor Fragment ◽  
Dose Dependent

Recent studies have demonstrated that glycine blunts the response of Kupffer cells to endotoxin. Based on pharmacological evidence, it was hypothesized that Kupffer cells and other macrophages contain a glycine-gated chloride channel similar to the glycine receptor expressed in neuronal tissues. Moreover, glycine stimulates influx of radiolabeled chloride in Kupffer cells in a dose-dependent manner. RT-PCR was used to identify mRNA of both α- and β-subunits of the glycine receptor in rat Kupffer cells, peritoneal neutrophils, and splenic and alveolar macrophages, similar to the sequence generated from rat spinal cord. Importantly, the sequence of the cloned Kupffer cell glycine receptor fragment for the β-subunit was >95% homologous with the receptor from the spinal cord. Membranes of these cells also contain a protein that is immunoreactive with antibodies against the glycine-gated chloride channel. These data demonstrate that Kupffer cells, as well as other macrophages and leukocytes, express mRNA and protein for a glycine-gated chloride channel with both molecular and pharmacological properties similar to the channel expressed in the central nervous system.

Production of superoxide and TNF-α from alveolar macrophages is blunted by glycine

1999 ◽  
Vol 277 (5) ◽  
pp. L952-L959 ◽  
Author(s):  
Michael D. Wheeler ◽  
Ronald G. Thurman
Keyword(s):  
Intracellular Calcium ◽  
Kupffer Cells ◽  
Alveolar Macrophages ◽  
Chloride Channel ◽  
Chloride Channels ◽  
Dependent Manner ◽  
Tnf Α ◽  
The Central Nervous System ◽  
Factor Α ◽  
Dose Dependent

Glycine blunts lipopolysaccharide (LPS)-induced increases in intracellular calcium concentration ([Ca2+]i) and tumor necrosis factor-α (TNF-α) production by Kupffer cells through a glycine-gated chloride channel. Alveolar macrophages, which have a similar origin as Kupffer cells, play a significant role in the pathogenesis of several lung diseases including asthma, endotoxemia, and acute inflammation due to inhaled bacterial particles and dusts. Therefore, studies were designed here to test the hypothesis that alveolar macrophages could be inactivated by glycine via a glycine-gated chloride channel. The ability of glycine to prevent endotoxin [lipopolysaccharide (LPS)]-induced increases in [Ca2+]iand subsequent production of superoxide and TNF-α in alveolar macrophages was examined. LPS caused a transient increase in intracellular calcium to nearly 200 nM, with EC50values slightly greater than 25 ng/ml. Glycine, in a dose-dependent manner, blunted the increase in [Ca2+]i, with an IC50less than 100 μM. Like the glycine-gated chloride channel in the central nervous system, the effects of glycine on [Ca2+]iwere both strychnine sensitive and chloride dependent. Glycine also caused a dose-dependent influx of radiolabeled chloride with EC50values near 10 μM, a phenomenon which was also inhibited by strychnine (1 μM). LPS-induced superoxide production was also blunted in a dose-dependent manner by glycine and was reduced ∼50% with 10 μM glycine. Moreover, TNF-α production was also inhibited by glycine and also required nearly 10 μM glycine for half-inhibition. These data provide strong pharmacological evidence that alveolar macrophages contain glycine-gated chloride channels and that their activation is protective against the LPS-induced increase in [Ca2+]iand subsequent production of toxic radicals and cytokines.

Kupffer cells contain a glycine-gated chloride channel

1997 ◽  
Vol 272 (6) ◽  
pp. G1581-G1586 ◽  
Author(s):  
K. Ikejima ◽  
W. Qu ◽  
R. F. Stachlewitz ◽  
R. G. Thurman
Keyword(s):  
Kupffer Cells ◽  
Chloride Channel ◽  
Glycine Receptor ◽  
Inhibitory Effect ◽  
High Dose ◽  
Necrosis Factor Alpha ◽  
Low Concentrations ◽  
Cell Plasma ◽  
The Central Nervous System ◽  
High Concentrations

Here the effect of glycine on intracellular Ca2+ concentration ([Ca2+]i) in cultured Kupffer cells stimulated with lipopolysaccharide (LPS) was investigated to assess the possibility that they contain a glycine-gated chloride channel. LPS (10 micrograms/ml) increased [Ca2+]i rapidly, with peak values reaching 307 +/- 29 nM. Glycine (1 mM) prevented this increase nearly completely. Low concentrations of strychnine (1 microM), a glycine receptor antagonist, reversed the inhibitory effect of glycine completely; however, high concentrations of strychnine (1 mM) mimicked glycine. The effects of glycine and high-dose strychnine were prevented when cells were incubated in chloride-free buffer. Furthermore, potassium (25 mM) and LPS depolarized the Kupffer cell plasma membrane, whereas glycine caused hyperpolarization and prevented depolarization due to potassium and LPS. Moreover, tumor necrosis factor-alpha (TNF-alpha) production in cultured Kupffer cells due to LPS was decreased significantly by glycine. Therefore, it is concluded that Kupffer cells contain a glycine-gated chloride channel similar to that described previously in the central nervous system. Prevention of increases in [Ca2+]i due to LPS by activation of chloride influx reduced synthesis and release of toxic mediators by Kupffer cells.

scholarly journals Oestrogen-Dependent Oxytocin Dynamics in the Hypothalamus of Female Rats

2021 ◽  
Author(s):  
Kazuaki Nishimura ◽  
Kiyoshi Yoshino ◽  
Naofumi Ikeda ◽  
Kazuhiko Baba ◽  
Kenya Sanada ◽  
...  
Keyword(s):  
Systemic Circulation ◽  
Female Rats ◽  
Dependent Manner ◽  
Transgenic Rats ◽  
Dynamic Changes ◽  
Hypothalamic Nuclei ◽  
The Central Nervous System ◽  
Posterior Pituitary Gland ◽  
Dose Dependent ◽  
Ovariectomised Rats

Abstract Oxytocin (OXT) is produced in the hypothalamic nuclei and is secreted into systemic circulation from the posterior pituitary gland (PP). In the central nervous system, OXT regulates behaviours including maternal and feeding behaviours. Our aim was to evaluate whether oestrogen regulates hypothalamic OXT dynamics. Herein, we provide the first evidence that OXT dynamics in the hypothalamus vary with sex and that oestrogen may modulate dynamic changes in OXT levels, using OXT-mRFP1 transgenic rats. The fluorescence intensity of OXT-mRFP1 in the hypothalamic nuclei and PP was most strongly expressed during the oestrus stage in female rats and decreased significantly in ovariectomised rats. Oestrogen replacement caused significant increases in the fluorescent intensities in the hypothalamic nuclei and PP in a dose-dependent manner. This was also demonstrated in feeding behaviour and hypothalamic Fos neurons using immunohistochemistry. Hypothalamic OXT expression was oestrogen dependent and could be enhanced centrally by the administration of oestrogen.

scholarly journals Antineuroinflammatory Activities and Neurotoxicological Assessment of Curcumin Loaded Solid Lipid Nanoparticles on LPS-Stimulated BV-2 Microglia Cell Models

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1170 ◽  
Author(s):  
Palanivel Ganesan ◽  
Byungwook Kim ◽  
Prakash Ramalingam ◽  
Govindarajan Karthivashan ◽  
Vishnu Revuri ◽  
...  
Keyword(s):  
Solid Lipid Nanoparticles ◽  
Lipid Nanoparticles ◽  
Brain Cells ◽  
No Production ◽  
Dependent Manner ◽  
Microglia Cell ◽  
Solid Lipid ◽  
Cytokine Levels ◽  
The Central Nervous System ◽  
Dose Dependent

Curcumin, which is a potential antineuroinflammatory and neuroprotective compound, exhibits poor bioavailability in brain cells due to its difficulty in crossing the blood–brain barrier and its rapid metabolism during circulation, which decreases its efficacy in treating chronic neuroinflammatory diseases in the central nervous system. The bioavailability and potential of curcumin can be improved by using a nanodelivery system, which includes solid lipid nanoparticles. Curcumin-loaded solid lipid nanoparticles (SLCN) were efficiently developed to have a particle size of about 86 nm and do not exhibit any toxicity in the endothelial brain cells. Furthermore, the curcumin-loaded solid lipid nanoparticles (SLCN) were studied to assess their efficacy in BV-2 microglial cells against LPS-induced neuroinflammation. The SLCN showed a higher inhibition of nitric oxide (NO) production compared to conventional curcumin in a dose-dependent manner. Similarly, the mRNA and proinflammatory cytokine levels were also reduced in a dose-dependent manner when compared to those with free curcumin. Thus, SLCN could be a potential delivery system for curcumin to treat microglia-mediated neuroinflammation.

scholarly journals EPH/EPHRIN SIGNALING CONTROLS PROGENITOR IDENTITIES IN THE VENTRAL SPINAL CORD

2016 ◽  
Author(s):  
Julien Laussu ◽  
Christophe Audouard ◽  
Anthony Kischel ◽  
Poincyane Assis-Nascimento ◽  
Nathalie Escalas ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Sonic Hedgehog ◽  
Cell Communication ◽  
Dependent Manner ◽  
Eph Receptors ◽  
Loss Of Function ◽  
Summary Statement ◽  
Dose Dependent ◽  
Ventral Spinal Cord

SUMMARY STATEMENTThis article by Laussu et al. describes a role for Eph:ephrin signaling in controlling the identity of neural progenitors in the ventral spinal cord.Early specification of progenitors of the ventral spinal cord involves the morphogen Sonic Hedgehog which induces distinct progenitor identities in a dose-dependent manner. Following these initial patterning events, progenitor identities have to be maintained in order to generate appropriate numbers of progeny. Here we provide evidence that communication via Eph:ephrin signaling is required to maintain progenitor identities in the ventral spinal cord. We show that ephrinB2 and ephrinB3 are expressed in restricted progenitor domains in the ventral spinal cord while several Eph receptors are more broadly expressed. Further, we provide evidence that expression of Efnb3 and EphA4 is controlled by Shh. Genetic loss-of-function analyses indicate that expression of ephrinB2 and ephrinB3 is required to control progenitor identities and in vitro experiments reveal that activation of Eph forward signaling in spinal progenitors up-regulates the expression of the identity transcription factor Nkx2.2. Altogether our results indicate that cell-to-cell communication is necessary to control progenitor identity in the ventral spinal cord.

Involvement of the 5-HT3 receptor in CRH-induced defecation in rats

1998 ◽  
Vol 274 (5) ◽  
pp. G827-G831 ◽  
Author(s):  
Keiji Miyata ◽  
Hiroyuki Ito ◽  
Shin Fukudo
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Restraint Stress ◽  
Dependent Manner ◽  
Corticotropin Releasing Hormone ◽  
Receptor Antagonists ◽  
Releasing Hormone ◽  
The Central Nervous System ◽  
Dose Dependent

We evaluated the possibility that serotonin (5-HT) mediates defecation induced by corticotropin-releasing hormone (CRH) exogenously administered or released from the central nervous system by stress via the 5-HT3 receptor in rats. Intracerebroventricular (ICV) injection of CRH (1, 3, and 10 μg/rat) dose dependently increased the number of stools excreted in rats, whereas intravenous (IV) injection of up to 100 μg/kg CRH did not affect defecation. α-Helical CRH-(9—41) and 5-HT3 receptor antagonists ramosetron and azasetron inhibited CRH (10 μg icv)-induced defecation in a dose-dependent manner with ED50 values of 4.3 μg/kg iv, 3.8 μg/kg po, and 70.4 μg/kg po, respectively. α-Helical CRH-(9—41) also inhibited CRH-induced defecation by ICV injection with an ED50 value of 0.078 μg/rat. In contrast, ramosetron and azasetron injectied ICV had no effect on CRH-induced defecation. α-Helical CRH-(9—41), ramosetron, and azasetron reduced defecation caused by restraint stress with ED50 values of 0.32, 3.6, and 19.7 μg/kg iv, respectively. These results indicate that CRH exogenously administered or released from the central nervous system by stress peripherally promotes the release of 5-HT, which in turn stimulates defecation through the 5-HT3 receptor.

scholarly journals Cellular and Molecular Evidence of Acetaldehyde Elimination and Intracellular Environment Antioxidation by L-Cysteine

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Zhenjing Li ◽  
Xiaohong Zhang ◽  
Yibin Xue ◽  
Jingkai Zhang ◽  
Meiling Li ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
A549 Cells ◽  
Control Group ◽  
Molecular Evidence ◽  
Protective Mechanism ◽  
Colorimetric Determination ◽  
Dependent Manner ◽  
Protective Effects ◽  
Dapi Staining ◽  
Dose Dependent

Acetaldehyde is a harmful metabolite of smoking and drinking. This study was initially intended to facilitate the understanding of the possible injury mechanism of A549 cells damaged by acetaldehyde and the possible protective mechanism of L-cysteine (L-Cys) by analyzing the oxidative damage indicators, as well as the changes in cell morphology and gene expression. Results from the dithiodimorpholine nitrobenzoic acid colorimetric determination for glutathione peroxidase (GSH-Px) activity in L-Cys groups were significantly higher (P<0.01) than those in the acetaldehyde group in a dose-dependent manner. The expression of cytochrome c oxidase subunit II (COII) mRNA was significantly reduced compared with the control group (P<0.01) and was noticeably restored in the L-Cys groups. Scanning electronic microscopy observation, DAPI staining, and flow cytometry also indicated that L-Cys could effectively attenuate the oxidative damage to A549 cells caused by acetaldehyde and reduces the rate of apoptosis. In conclusion, the protective effects of L-Cys on A549 cells against oxidative damage by acetaldehyde were dose-dependent within the range of 10 μmol/L to 160 μmol/L. Acetaldehyde damaged the mitochondria and resulted in the apoptosis of A549 cells by reactive oxygen species (ROS), e.g., free radicals, but L-Cys reversed the release of cytochrome c from the mitochondria, reduced the rate of apoptosis, and protected cells from ROS and oxidative stress.

Effects of 2-buten-4-olide, an endogenous satiety substance, on plasma glucose, corticosterone, and catecholamines

1994 ◽  
Vol 266 (2) ◽  
pp. R413-R418 ◽  
Author(s):  
I. Matsumoto ◽  
Y. Oomura ◽  
H. Nishino ◽  
S. Nemoto ◽  
S. Aou ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Plasma Glucose ◽  
Jugular Vein ◽  
Corticotropin Releasing Factor ◽  
Dependent Manner ◽  
Indwelling Catheter ◽  
The Central Nervous System ◽  
The Right ◽  
Dose Dependent

Effects of 2-buten-4-olide (2-B4O), an endogenous satiety substance, on levels of plasma glucose, corticosterone, and catecholamines were examined in fed, conscious, and unrestrained rats. A vascular indwelling catheter was inserted into the right atrium of the animal from the jugular vein 1 wk before the experiment. Injection of 2-B4O and blood sampling were performed through the catheter in an unanesthetized condition. The levels of plasma glucose, corticosterone, epinephrine, and norepinephrine increased significantly for 2 h after the start of intravenous injection of 2-B4O in a dose-dependent manner. The increases in glucose and catecholamines induced by 2-B4O injection were abolished by bilateral splanchnicotomy (SPX) but not by pretreatment with anti-corticotropin-releasing factor (CRF) antibody. The increase in corticosterone was abolished not by the SPX but by pretreatment with anti-CRF antibody. These findings suggest that 2-B4O, endogenously produced during food deprivation, may facilitate sympathoadrenal and hypothalamopituitary-adrenal functions through the central nervous system.

scholarly journals A Role of Fluoride on Free Radical Generation and Oxidative Stress in BV-2 Microglia Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Xi Shuhua ◽  
Liu Ziyou ◽  
Yan Ling ◽  
Wang Fei ◽  
Guifan Sun
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Dependent Manner ◽  
Microglia Cell ◽  
The Central Nervous System ◽  
Radical Generation ◽  
Oxide Synthase ◽  
Cell Medium ◽  
Dose Dependent

The generation of ROS and lipid peroxidation has been considered to play an important role in the pathogenesis of chronic fluoride toxicity. In the present study, we observed that fluoride activated BV-2 microglia cell line by observing OX-42 expression in immunocytochemistry. Intracellular superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), reactive oxygen species (ROS), superoxide anions (O2∙-), nitric oxide synthase (NOS), nitrotyrosine (NT) and nitric oxide (NO), NOS in cell medium were determined for oxidative stress assessment. Our study found that NaF of concentration from 5 to 20 mg/L can stimuli BV-2 cells to change into activated microglia displaying upregulated OX-42 expression. SOD activities significantly decreased in fluoride-treated BV-2 cells as compared with control, and MDA concentrations and contents of ROS andO2∙-increased in NaF-treated cells. Activities of NOS in cells and medium significantly increased with fluoride concentrations in a dose-dependent manner. NT concentrations also increased significantly in 10 and 50 mg/L NaF-treated cells compared with the control cells. Our present study demonstrated that toxic effects of fluoride on the central nervous system possibly partly ascribed to activiting of microglia, which enhanced oxidative stress induced by ROS and reactive nitrogen species.

Evaluation of the Analgesic Effect of Aqueous Extract of Brugmansia suaveolens Flower in Mice: Possible Mechanism Involved

2010 ◽  
Vol 11 (4) ◽  
pp. 345-350 ◽  
Author(s):  
Ana Luiza Muccillo-Baisch ◽  
Alexander Garcia Parker ◽  
Gianni Peraza Cardoso ◽  
Marta Regina Cezar-Vaz ◽  
Maria Cristina Flores Soares
Keyword(s):  
Aqueous Extract ◽  
Benzodiazepine Receptors ◽  
Antinociceptive Effect ◽  
Dependent Manner ◽  
Hot Plate Test ◽  
Antinociceptive Effects ◽  
Brugmansia Suaveolens ◽  
The Central Nervous System ◽  
Dose Dependent ◽  
Abdominal Constriction

The study was conducted to test the aqueous extract of Brugmansia suaveolens (AEBs) flowers for their antinociceptive effects in mice. In the hot plate test, a significant increase in reaction time for two doses of AEBs at 60, 90, 120, and 150 min after treatment was noted. Pretreatment of animals with naloxone (5 mg/kg, intraperitoneally [IP]) left the antinociceptive effect of AEBs at a dose of 100 mg/kg unaffected at 60, 90, 120, and 150 min after treatment and at a dose of 300 mg/kg at 30 min but not at 90, 120, and 150 min. In the writhing test, the AEBs significantly inhibited acetic acid—induced abdominal constriction and was equally potent at both doses. Pretreatment with naloxone (5 mg/kg, IP) left the antinociceptive effect of both doses of AEBs unaffected. Pretreatment with NG-nitro-L-arginine methyl ester (L-NAME; 20 mg/kg, IP) caused a significant change in the number of abdominal constrictions but did not change the antinociceptive effect of AEBs. Pretreatment of animals with methylene blue also did not change the effect of AEBs on the number of writhing movements in mice. Flumazenil (5 mg/kg, IP) antagonized the antinociceptive effects of diazepam and also reversed the antinociceptive effect of AEBs. AEBs showed a depressant effect on the central nervous system, and the treatment of mice with pentobarbital combined with AEBs increased the animals’ sleeping time in a dose-dependent manner. These results suggest that the antinociceptive activity of AEBs may be related in part to benzodiazepine receptors, although peripheral mechanisms cannot be excluded.

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