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ABSTRACT: Hepatic ischemia/reperfusion (I/R) elicits an excessive inflammatory response, posing a lethal threat to the host. Local inflammation may be regulated by the vagus nerve and activation of the nicotinic acetylcholine receptors may also suppress peripheral inflammation. We have previously demonstrated that heme oxygenase-1 (HO-1) protects the liver against I/R injury by modulating proinflammatory mediators. Here, we investigate the cytoprotective mechanisms of nicotine, a nicotinic acetylcholine receptor agonist, against liver injury caused by I/R. Mice were subjected to 60min of ischemia followed by 3h of reperfusion. Nicotine (0.1, 0.3 and 1mg/kg) and vehicle (saline) were administered intraperitoneally 20min prior to ischemia. Serum alanine aminotransferase activity and lipid peroxidation levels increased after reperfusion, while total glutathione content decreased. These changes were markedly attenuated by nicotine. The levels of HO activity and HO-1 protein expression increased after reperfusion, and nicotine markedly augmented these increases. Serum levels of high mobility group box 1 and tumor necrosis factor-α increased after reperfusion, and nicotine prevented these increases. The nuclear translocation of NF-E2-related factor 2 and phosphorylation of both phosphatidyl inositol 3-kinase and Akt increased; nicotine also augmented these increases. The protein expression of nuclear factor-κB increased and nicotine attenuated this increase. Methyllycaconitine, a selective α7 nicotinic acetylcholine receptor antagonist, abolished these effects of nicotine. Furthermore, zinc protoporphyrin, an HO-1 inhibitor, also reversed the observed effects of nicotine. Our findings suggest that activation of α7 nicotinic acetylcholine receptor by nicotine ameliorates I/R-induced liver injury, and that this protection is likely due to inhibition of the inflammatory response through HO-1 induction.
European journal of pharmacology 03/2013; · 2.59 Impact Factor
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ABSTRACT: The purpose of this study was to investigate the protective effects and molecular mechanisms of scoparone on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced fulminant hepatic failure (FHF) in mice. FHF was induced in mice by intraperitoneal injection of D-GalN (800 mg/kg)/LPS (40 μg/kg). Mice were treated intraperitoneally with scoparone 1 h before D-GalN/LPS treatment. Treatment with D-GalN/LPS markedly increased mortality, serum aminotransferase activity, and tolllike receptor 4 (TLR4) protein expression, and these increases were attenuated by scoparone. Treatment with D-GalN/LPS markedly increased myeloid differentiation primary response gene 88 protein expression, phosphorylation of p38, extracellular signal-regulated kinase and c-Jun N-terminal kinase, nuclear protein expression of nuclear factor κB and phosphorylated c-Jun, and levels of serum tumor necrosis factor-α and interleukin-6 and these increases were attenuated by scoparone. In addition, increased levels of toll-receptor-associated activator of interferon protein expression, phosphorylation of interferon (IFN) regulatory factor 3, and serum IFN-β level in D-GalN/LPS-treated mice were attenuated by scoparone. Our results suggest that scoparone attenuates D-GalN/LPSinduced liver damage by inhibition of the TLR-mediated inflammatory pathway.
Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 03/2013; · 2.99 Impact Factor
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ABSTRACT: The cytoprotective mechanisms of melatonin in hepatic ischemia/reperfusion (I/R) injury associated with heme oxygenase-1 (HO-1) induction and type 1 interferon (IFN) signaling pathway downstream of toll-like receptor 4 (TLR4) were investigated. Rats were subjected to 60min of ischemia followed by 5-hr reperfusion. Melatonin (10mg/kg) or vehicle (5% ethanol in saline) was administered intraperitoneally 15min prior to ischemia and immediately before reperfusion. Rats were pretreated with zinc protoporphyrin (ZnPP, 10mg/kg, i.p.), a HO-1 inhibitor, at 16 and 3hr prior to ischemia. Melatonin attenuated the I/R-induced increase in serum alanine aminotransferase activity, and ZnPP reversed this attenuation. Melatonin augmented the levels of HO activity and HO-1 protein and mRNA expression, and this enhancement was reversed by ZnPP. Melatonin enhanced the level of NF-E2-related factor-2 (Nrf2) nuclear translocation, and ZnPP reversed this increase. Overexpression of TLR4 and its adaptor proteins, toll-receptor-associated activator of interferon (TRIF), and myeloid differentiation factor 88 (MyD88), induced by I/R, was attenuated by melatonin; ZnPP reversed the effect of melatonin on TLR4 and TRIF expression. Melatonin suppressed the increased interaction between TLR4/TRIF and TLR4/MyD88, which was reversed by ZnPP. Melatonin attenuated the increased levels of JAK2 and STAT1 activation as well as IFN-β, and ZnPP reversed these inhibitory effects of melatonin. Melatonin inhibited the level of chemokine (C-X-C motif) ligand 10 (CXCL-10), and ZnPP reversed this inhibition. Our findings suggest that melatonin protects the liver against I/R injury by HO-1 overexpression, which suppresses the type 1 IFN signaling pathway downstream of TLR4.
Journal of Pineal Research 01/2012; 53(1):67-76. · 5.79 Impact Factor
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ABSTRACT: Therapeutic effects of GCSB-5 on osteoarthritis were measured by the amount of glycosaminoglycan in rabbit articular cartilage explants in vitro, in experimental osteoarthritis induced by intra-articular injection of monoiodoacetate in rats in vivo. GCSB-5 was orally administered for 28 days. In vitro, GCSB-5 inhibited proteoglycan degradation. GCSB-5 significantly suppressed the histological changes in monoiodoacetate-induced osteoarthritis. Matrix metalloproteinase (MMP) activity, as well as, the levels of serum tumor necrosis factor-α, cyclooxygenase-2, inducible nitric oxide synthase protein, and mRNA expressions were attenuated by GCSB-5, whereas the level of interleukin-10 was potentiated. By GCSB-5, the level of nuclear factor-κB p65 protein expression was significantly attenuated but, on the other hand, the level of inhibitor of κB-α protein expression was increased. These results indicate that GCSB-5 is a potential therapeutic agent for the protection of articular cartilage against progression of osteoarthritis through inhibition of MMPs activity, inflammatory mediators, and NF-κB activation.
Evidence-based Complementary and Alternative Medicine 01/2012; 2012:730907. · 4.77 Impact Factor
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ABSTRACT: Hepatic ischemia and reperfusion injury (I/R) is accompanied by excessive reactive oxygen species and resultant sterile inflammation. Chlorogenic acid (CGA), one of the most abundant polyphenols in the human diet, has been shown to exert potent anti-inflammatory, antibacterial and antioxidant activities. Thus, the purpose of the present study was to investigate protective effects of CGA and its molecular mechanisms against hepatic I/R injury. Rats were subjected to 60 min of partial hepatic ischemia followed by 5 h of reperfusion. CGA (2.5, 5 and 10 mg/kg, ip) was administered twice: 10 min prior to ischemia and 10 min before reperfusion. CGA treatment resulted in marked improvement of hepatic function and histology, and suppressed oxidative stress, as indicated by hepatic lipid peroxidation and glutathione level. Levels of serum tumor necrosis factor-α, inducible nitric oxide synthase and cyclooxygenase-2 protein and mRNA expressions were up-regulated after I/R; these effects were attenuated by CGA. Immunoblot results showed that CGA reduced I/R-induced toll-like receptor 4 overexpression, nuclear translocation of nuclear factor kappa B and interferon regulatory factor-1, high-mobility group box-1 release into extracellular milieu, and enhanced heme oxygenase-1 expression and nuclear translocation of nuclear factor erythroid 2-related factor 2. Our results suggest that CGA alleviates I/R-induced liver injury and that this protection is likely due to inhibition of inflammatory response and enhancement of antioxidant defense systems. Therefore, CGA might have potential as an agent for use in clinical treatment of hepatic I/R injury.
The Journal of nutritional biochemistry 12/2011; 23(10):1249-55. · 4.29 Impact Factor
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ABSTRACT: This study was designed to investigate the hepatoprotective effects of magnesium chenoursodeoxycholic acid (Mg-CUD), a magnesium trihydrate salt of ursodeoxycholic acid and chenodeoxycholic acid, in carbon tetrachloride (CCl(4))-induced liver fibrosis in rats. Rats were treated with CCl(4) dissolved in olive oil (0.5 mL/kg, twice a week) intraperitoneally for eight weeks. Mg-CUD was administered orally at 15.625, 31.25, 62.5 and 125 mg/kg once a day. Chronic CCl(4) administration induced increases in serum transforming growth factor-β1, hepatic hydroxyproline content and serum alanine aminotransferase activity. Mg-CUD attenuated these increases. The levels of α-smooth muscle actin protein and mRNA expression were increased by chronic CCl(4) exposure and Mg-CUD attenuated these increases. Mg-CUD suppressed increases in matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 mRNA expression and elevation of oxidative stresses by attenuating lipid peroxidation and enhancing reduced glutathione/oxidized glutathione ratio. The overexpression of toll-like receptor 4 and increased nuclear translocation of nuclear factor-κB and phosphorylated c-Jun, a component of activator protein 1, were suppressed by Mg-CUD. Furthermore, CCl(4) increased the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-10 and cyclooxygenase (COX)-2. Mg-CUD attenuated the levels of TNF-α, IL-6 and COX-2, while it augmented the level of IL-10. Our results suggest that Mg-CUD may prevent liver fibrosis by modulating collagen accumulation and inflammatory signaling pathways.
Experimental Biology and Medicine 12/2011; 237(1):83-92. · 2.64 Impact Factor
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ABSTRACT: This study investigated the immunomodulating effect of melatonin on toll-like receptor (TLR)-stimulated signal transduction. Rats were subjected to 60 min of ischemia followed by 1 or 5 hr of reperfusion. Melatonin (10 mg/kg) or the vehicle was administered intraperitoneally 15 min prior to ischemia and immediately before reperfusion. Melatonin treatment significantly reduced the level of serum alanine aminotransferase activity. Increased levels of TLR3 and TLR4 protein expression induced by ischemia/reperfusion (I/R) were attenuated by melatonin. Serum level of high-mobility group box 1 (HMGB1), a potent alarmin of the TLR system, increased significantly in the I/R group, and melatonin inhibited this release. Melatonin suppressed the increase in myeloid differentiation factor 88 (MyD88) protein expression, extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) phosphorylation and nuclear translocation of nuclear factor κB (NF-κB) and phosphorylated c-Jun, a component of activator protein 1. The increased level of toll-receptor-associated activator of interferon (TRIF) expression, phosphorylation of interferon (IFN) regulatory factor 3 (IRF3) and serum IFN-β was attenuated by melatonin. Melatonin attenuated the levels of tumor necrosis factor alpha (TNF-α), interleukin (IL)-6 and inducible nitric oxide synthase (iNOS) protein and mRNA expression, while the level of heme oxygenase-1 (HO-1) was augmented. Our results suggest that melatonin ameliorates I/R-induced liver damage by modulation of TLR-mediated inflammatory responses.
Journal of Pineal Research 02/2011; 50(4):403-11. · 5.79 Impact Factor
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ABSTRACT: This study examined the protective effects of magnesium chenoursodeoxycholic acid (Mg-CUD), a magnesium trihydrate salt of chenodeoxycholic acid (CDCA) and ursodeoxycholic acid (UDCA), against D-galactosamine (D-GalN)-induced liver injury. Hepatotoxicity was induced by intraperitoneal injection of D-GalN (700mg/kg) and Mg-CUD (15.625, 31.25 and 62.5mg/kg) was administered orally once a day for 2weeks and 6h after D-GalN injection. Significant increases in the level of serum alanine aminotransferase activity and lipid peroxidation were attenuated by Mg-CUD 24h after D-GalN treatment. Hepatic glutathione/oxidized glutathione ratio was decreased, and this decrease was attenuated by Mg-CUD. Mg-CUD attenuated the increase in the levels of serum tumor necrosis factor (TNF)-α and interleukin (IL)-6, while it augmented the increase in serum IL-10 level and heme oxygenase (HO)-1 protein expression. Mg-CUD attenuated increased levels of TNF-α, IL-6, and IL-1β mRNA expression. Increased levels of IL-10 and HO-1 mRNA expression were augmented by Mg-CUD. The increased nuclear level of nuclear factor-κB (NF-κB) and decreased cytosolic level of Inhibitory κB-α protein were attenuated by Mg-CUD. Nuclear phosphorylated c-Jun (p-c-Jun) level showed a significant increase and this increase was attenuated by Mg-CUD. Our results suggest that Mg-CUD ameliorates D-GalN-induced acute hepatitis and that this protection is likely due to its anti-oxidative and anti-inflammatory activities, and inhibition of NF-κB nuclear translocation and nuclear p-c-Jun expression.
European journal of pharmacology 01/2011; 657(1-3):138-43. · 2.59 Impact Factor
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ABSTRACT: Ictal Single Proton Emission Computed Tomography (SPECT) has demonstrated high levels of sensitivity in localizing seizures among patients with epilepsy of the mesial temporal lobe (mTLE). However, incorrect information on the lateralization of mTLE has also been reported. In order to investigate the causes of these incorrect localizations, the authors assessed clinical symptoms, as well as the electroencephalography (EEG) and brain SPECT scan data of five patients with mTLE experiencing ictal hyperperfusion of the contralateral temporal lobe. All patients underwent presurgical evaluations, including an interictal and ictal brain SPECT scan. A subtraction ictal SPECT co-registered with Magnetic Resonance Imaging (MRI) procedure or SISCOM was performed. Hyperperfusion (ictal perfusion greater than interictal perfusion) and hypoperfusion (ictal perfusion lower than interictal perfusion), results of SISCOM were analyzed and compared with seizure and ictal EEG pattern patterns. All the five patients had unilateral hippocampal sclerosis, and the radiotracer for the ictal SPECT was injected after the ictal EEG pattern had propagated to the contralateral side. The average delay between the ictal EEG onset and the radiotracer injection was 29.7+/-9.6s. All hyperperfusion SISCOM results revealed hyperperfusion in the contralateral temporal region with a more intense ictal EEG build-up. However, hypoperfusion SISCOM results demonstrated significant hypoperfusion in the epileptogenic temporal lobe of three of the five patients, but no hypoperfusion finding in the other two patients. This study demonstrates that early ictal EEG pattern propagation to the contralateral side in mTLE may be associated with contralateral ictal hyperperfusion with or without ipsilateral temporal hypoperfusion. The authors recommend simultaneous interpretations of ictal SPECT and ictal EEG propagation patterns at the time of the injection of radiotracers.
Epilepsy research 02/2010; 88(2-3):247-54. · 2.48 Impact Factor
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ABSTRACT: To investigate differences in brain gray matter concentrations or volumes in patients with obstructive sleep apnea syndrome (OSA) and healthy volunteers.
Optimized voxel-based morphometry, an automated processing technique for MRI, was used to characterize structural differences in gray matter in newly diagnosed male patients.
University hospital.
The study consisted of 36 male OSA and 31 non-apneic male healthy volunteers matched for age (mean age, 44.8 years).
Using the t-test, gray matter differences were identified. The statistical significance level was set to a false discovery rate P < 0.05 with an extent threshold of k(E) > 200 voxels.
The mean apnea-hypopnea index (AHI) of patients was 52.5/h. On visual inspection of MRI, no structural abnormalities were observed. Compared to healthy volunteers, the gray matter concentrations of OSA patients were significantly decreased in the left gyrus rectus, bilateral superior frontal gyri, left precentral gyrus, bilateral frontomarginal gyri, bilateral anterior cingulate gyri, right insular gyrus, bilateral caudate nuclei, bilateral thalami, bilateral amygdalo-hippocampi, bilateral inferior temporal gyri, and bilateral quadrangular and biventer lobules in the cerebellum (false discovery rate P < 0.05). Gray matter volume was not different between OSA patients and healthy volunteers.
The brain gray matter deficits may suggest that memory impairment, affective and cardiovascular disturbances, executive dysfunctions, and dysregulation of autonomic and respiratory control frequently found in OSA patients might be related to morphological differences in the brain gray matter areas.
Sleep 02/2010; 33(2):235-41. · 5.05 Impact Factor
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ABSTRACT: Palmatine is an isoquinoline alkaloid from Coptis chinensis, an herbal medicine used to treat various inflammatory diseases such as gastritis, edema and dermatitis. The present study examined the cytoprotective properties of palmatine on d(+)-galactosamine (GalN)/lipopolysaccharide (LPS)-induced fulminant hepatic failure. Mice were intraperitoneally given GalN (700 mg/kg)/LPS (10 microg/kg). Palmatine (25, 50, 100, and 200mg/kg) was administered 1h before GalN/LPS. GalN/LPS increased the mortality and serum aminotransferase activities. These increases were attenuated by palmatine. GalN/LPS increased hepatic lipid peroxidation and decreased the contents of reduced glutathione. Palmatine did not affect the lipid peroxidation and glutathione content. GalN/LPS increased the circulating levels of tumor necrosis factor (TNF)-alpha, interleukin-6 (IL-6) and IL-10. Palmatine prevented the increase of serum TNF-alpha and augmented that of serum IL-10. GalN/LPS treatment also increased the levels of TNF-alpha, IL-6 and IL-10 mRNA expression in liver tissue. Palmatine decreased the TNF-alpha mRNA expression and increased the IL-10 mRNA expression. Palmatine attenuated the apoptosis of hepatocytes, as evidenced by the TUNEL method and capase-3 analysis. Our data suggest that palmatine alleviates GalN/LPS-induced liver injury by modulating the cytokine response and inhibiting apoptosis.
Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 10/2009; 48(1):222-8. · 2.99 Impact Factor
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Ki-Hong Kim,
Jung-Hyun Shim,
Eun-Hee Seo,
Min-Chul Cho, Jung-Woo Kang,
Soo-Hyun Kim,
Dae-Yeul Yu,
Eun-Young Song,
Hee-Gu Lee,
Jung-Hoon Sohn,
JinMan Kim,
Charles A Dinarello,
Do-Young Yoon
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ABSTRACT: The members of the IL-1 family play important roles in the development and pathogenesis of autoimmune and inflammatory diseases. Especially, IL-1 and IL-18 belong to the IL-1 family because they share structural similarity and require caspase-1 for processing. Currently, IL-18 has been studied for its biological effects in the broad spectrum of Th1- or Th2- related autoimmune diseases. IL-18 also uses a similar signaling pathway as that of IL-1 family members. Taken together these results, IL-18-inducible genes might also contribute to autoimmune and inflammatory diseases. It has recently been reported that an inducer of TNF-alpha was identified as one of IL-18 inducible genes in IL-18 responsible cells and named as a new cytokine IL-32. We have produced novel monoclonal anti IL-32 antibodies in order to help study IL-32 function and to develop improved diagnosis of IL-32-expressing tumors. Several mAbs reactive to IL-32 isoforms were prepared and characterized by the epitope analysis and Western blotting performed using various deletion mutants and IL-32 isoforms (IL-32alpha, beta, gamma, and delta). In order to optimize the sandwich ELISA for IL-32, recombinant IL-32alpha was added, followed by the addition of a biotinylated mAb KU32-52 into the microtiter plate wells pre-coated with a mAb KU32-07 or mAb KU32-56. The bound mAb was probed with a streptavidin conjugated to HRP. The epitope analysis and Western blot analysis revealed that mAb KU32-07 could detect only IL-32alpha and KU32-52 was bound to all isoforms, whereas KU32-56 were reactive to IL-32 alpha, beta, delta isoforms but not gamma isoform. These sandwich ELISAs were highly specific and had a minimal detection limit of 80 pg/ml (mean+3 SD of zero calibrator) and measuring range of up to 3000 pg/ml. An ELISA using a coating mAb KU32-07 and a capturing biotinylated mAb KU32-52 had no cross-reaction with other cytokines such as IL-32beta, IL-32gamma, IL-32delta, hIL-1alpha , IL-1beta , hIL-2, hIL-6, hIL-8, hIL-10, hIL-18, and hTNF-alpha. Intra-assay coefficients of variation were 11 to 6% (n=16) and inter-assay coefficients were 10 to 5% (n=9). Another ELISA using a coating mAb KU32-56 and a capturing biotinylated mAb KU32-52 detected both IL-32alpha and IL-32beta isoforms but not gamma and delta isoforms and had no cross-reaction with other cytokines such as hIL-1alpha , IL-1beta , hIL-2, hIL-6, hIL-8, hIL-10, hIL-18, and hTNF-alpha. One mAb KU32-09 was shown to react strongly on immunohistochemistry. Our newly established mAbs, KU32-07, KU32-09, KU32-52, KU32-56, have different and useful properties for the detection of IL-32 by immunohistochemistry, ELISA, and Western blotting.
Journal of Immunological Methods 05/2008; 333(1-2):38-50. · 2.20 Impact Factor
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ABSTRACT: p38 is associated with a macromolecular tRNA synthetase complex. It has an essential role as a scaffold for the complex, and genetic disruption of p38 in mice causes neonatal lethality. Here we investigated the molecular mechanisms underlying lethality of p38-mutant mice. p38-deficient mice showed defects in lung differentiation and respiratory distress syndrome. p38 was found to interact with FUSE-binding protein (FBP), a transcriptional activator of c-myc. Binding of p38 stimulated ubiquitination and degradation of FBP, leading to downregulation of c-myc, which is required for differentiation of functional alveolar type II cells. Transforming growth factor-beta (TGF-beta) induced p38 expression and promoted its translocation to nuclei for the regulation of FBP and c-myc. Thus, this work identified a new activity of p38 as a mediator of TGF-beta signaling and its functional importance in the control of c-myc during lung differentiation.
Nature Genetics 08/2003; 34(3):330-6. · 35.53 Impact Factor
