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Yakut S, Gelen V, Kara H, Özkanlar S, Yeşildağ A. Silver Nanoparticles Loaded With Oleuropein Alleviates LPS-Induced Acute Lung Injury by Modulating the TLR4/P2X7 Receptor-Mediated Inflammation and Apoptosis in Rats. ENVIRONMENTAL TOXICOLOGY 2024. [PMID: 38980228 DOI: 10.1002/tox.24369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/30/2024] [Accepted: 05/23/2024] [Indexed: 07/10/2024]
Abstract
Toll-like receptor 4 (TLR-4) ligands were initially shown to be the source of lipopolysaccharide (LPS), a gram-negative bacterium's cell wall immunostimulatory component. Oxidative stress, apoptosis, and inflammation are all potential effects of LPS treatment on the lungs. By triggering oxidative stress and inflammation, these negative effects could be avoided. Robust flavonoid oleuropein (OLE) exhibits anti-inflammatory, antiproliferative, and antioxidative properties. A nanodelivery system could improve its low bioavailability, making it more effective and useful in treating chronic human ailments. This study evaluates the effects of AgNP-loaded OLE on LPS-induced lung injury in rats in terms of TLR4/P2X7 receptor-mediated inflammation and apoptosis. Forty-eight male albino rats were randomly divided into eight groups. Drugs were administered to the groups in the doses specified as follows: Control, LPS (8 mg/kg ip), OLE (50 mg/kg) AgNPs (100 mg/kg), OLE + AgNPs (50 mg/kg), LPS + OLE (oleuropein 50 mg/kg ig + LPS 8 mg/kg ip), LPS + AgNPs (AgNPs 100 mg/kg ig + LPS 8 mg/kg ip), and LPS + OLE + AgNPs (OLE + AgNPs 50 mg/kg + LPS 8 mg/kg ip). After the applications, the rats were decapitated under appropriate conditions, and lung tissues were obtained. Oxidative stress (SOD, MDA, and GSH), and inflammation (IL-6, IL-1β, TNF-α, Nrf2, P2X7R, AKT, and TLR4) parameters were evaluated in the obtained lung tissues. Additionally, histopathology studies were performed on lung tissue samples. The data obtained were evaluated by comparison between groups. Both OLE and OLE + AgNPs showed potential in reducing oxidative stress, inflammation, and apoptosis (p < 0.05). These findings were supported by histopathological analysis, which revealed that tissue damage was reduced in OLE and OLE + AgNPs-treated groups. According to the results, LPS-induced lung injury can be reduced by using nanotechnology and producing OLE + AgNP.
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Affiliation(s)
- Seda Yakut
- Department of Histology and Embryology, Faculty of Veterinary Medicine, Burdur Mehmet Akif Ersoy University, Burdur, Turkey
| | - Volkan Gelen
- Department of Physiology, Faculty of Veterinary Medicine, Kafkas University, Kars, Turkey
| | - Hülya Kara
- Department of Anatomy, Faculty of Veterinary Medicine, Atatürk University, Erzurum, Turkey
| | - Seçkin Özkanlar
- Department of Biochemistry, Faculty of Veterinary Medicine, Atatürk University, Erzurum, Turkey
| | - Ali Yeşildağ
- Department of Bioengineering, Faculty of Engineering and Architecture, Kafkas University, Kars, Turkey
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2
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Bao L, Liu Y, Jia Q, Chu S, Jiang H, He S. Argon neuroprotection in ischemic stroke and its underlying mechanism. Brain Res Bull 2024; 212:110964. [PMID: 38670471 DOI: 10.1016/j.brainresbull.2024.110964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/04/2024] [Accepted: 04/21/2024] [Indexed: 04/28/2024]
Abstract
Ischemic stroke (IS), primarily caused by cerebrovascular obstruction, results in severe neurological deficits and has emerged as a leading cause of death and disability worldwide. Recently, there has been increasing exploration of the neuroprotective properties of the inert gas argon. Argon has exhibited impressive neuroprotection in many in vivo and ex vivo experiments without signs of adverse effects, coupled with the advantages of being inexpensive and easily available. However, the efficient administration strategy and underlying mechanisms of neuroprotection by argon in IS are still unclear. This review summarizes current research on the neuroprotective effects of argon in IS with the goal to provide effective guidance for argon application and to elucidate the potential mechanisms of argon neuroprotection. Early and appropriate argon administration at as high a concentration as possible offers favorable neuroprotection in IS. Argon inhalation has been shown to provide some long-term protection benefits. Argon provides the anti-oxidative stress, anti-inflammatory and anti-apoptotic cytoprotective effects mainly around Toll-like receptor 2/4 (TLR2/4), mediated by extracellular signal-regulated kinase 1/2 (ERK1/2), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), nuclear factor kappa-B (NF-ĸB) and B-cell leukemia/lymphoma 2 (Bcl-2). Therefore, argon holds significant promise as a novel clinical neuroprotective gas agent for ischemic stroke after further researches to identify the optimal application strategy and elucidate the underlying mechanism.
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Affiliation(s)
- Li Bao
- Department of Stroke Center, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, People's Republic of China; Medical College of Nantong University, Nantong, Jiangsu 226019, People's Republic of China
| | - Yongxin Liu
- Medical College of Nantong University, Nantong, Jiangsu 226019, People's Republic of China
| | - Qi Jia
- Department of Stroke Center, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, People's Republic of China; Medical College of Nantong University, Nantong, Jiangsu 226019, People's Republic of China
| | - Sihao Chu
- Department of Stroke Center, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, People's Republic of China; Medical College of Nantong University, Nantong, Jiangsu 226019, People's Republic of China
| | - Han Jiang
- Department of Stroke Center, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, People's Republic of China; Medical College of Nantong University, Nantong, Jiangsu 226019, People's Republic of China
| | - Shuang He
- Department of Stroke Center, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, People's Republic of China.
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Xu Y, Li Q, Ge P, Mao H, Yang C. Chitosan nanoparticles attenuate intestinal damage and inflammatory responses in LPS-challenged weaned piglets via prevention of IκB degradation. J Anim Physiol Anim Nutr (Berl) 2023; 107:173-181. [PMID: 34820921 DOI: 10.1111/jpn.13664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 10/31/2021] [Accepted: 11/02/2021] [Indexed: 01/10/2023]
Abstract
Chitosan nanoparticles (CNP), widely applied as oral drug/gene/vaccine carrier, were found to have anti-inflammatory properties. In this study, the effects of CNP on lipopolysaccharide (LPS)-induced intestinal damage in weaned piglets and the related mechanisms were investigated. Twenty-four weaned piglets (Duroc × Landrace × Yorkshire, 21 ± 2 day of age, initial mass: 8.58 ± 0.59 kg) were randomly assigned into four groups: control, LPS, CNP and CNP + LPS. The control and LPS groups were fed a corn-soybean meal-based control diet, whereas the CNP and CNP + LPS groups were fed a control diet supplemented with 400 mg/kg CNP. After 28 days of feeding, piglets in LPS and CNP + LPS groups were injected with LPS (100 μg/kg); meanwhile, the piglets in control and CNP groups were injected with sterile saline. After 4 h from the LPS challenge, pigs were sacrificed to collect the intestinal samples for analysis. The results showed that CNP could attenuate the intestinal damages and inflammatory response stimulated by LPS treatment. LPS induced dramatically higher levels of CD177+ neutrophils invasion in jejunum mucosa (p < 0.01), which accompanied by increased secretion of marks of inflammation (p < 0.01) compared with the control, whereas CNP administration obviously inhibited LPS-induced CD177+ neutrophils invasion (p < 0.01) and secretion of marks of inflammation, such as interleukin-8 (p < 0.05), intercellular adhesion molecule-1 (p < 0.05) secretion in jejunum mucosa compared with LPS group. Moreover, CNP was shown to inhibit IκB-α degradation in cytoplasm, which resulted in reduced nuclear translocation of NF-κB p65 in LPS-challenged piglets. These findings suggest that CNP attenuates intestinal damage and inflammatory responses in LPS-challenged weaned piglets by impairing the NF-κB signalling pathway.
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Affiliation(s)
- Yinglei Xu
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology • College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Qing Li
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology • College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Pu Ge
- Pathophysiology Department of ChongQing Medical University, Chongqing, China
| | - Huiling Mao
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology • College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Caimei Yang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology • College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
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Ruiz VH, Encinas-Basurto D, Sun B, Eedara BB, Dickinson SE, Wondrak GT, Chow HHS, Curiel-Lewandrowski C, Mansour HM. Design, Physicochemical Characterization, and In Vitro Permeation of Innovative Resatorvid Topical Formulations for Targeted Skin Drug Delivery. Pharmaceutics 2022; 14:pharmaceutics14040700. [PMID: 35456534 PMCID: PMC9026853 DOI: 10.3390/pharmaceutics14040700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 02/04/2023] Open
Abstract
Nonmelanoma skin cancers (NMSCs) are the most common malignancies worldwide and affect more than 5 million people in the United States every year. NMSC is directly linked to the excessive exposure of the skin to solar ultraviolet (UV) rays. The toll-like receptor 4 (TLR4) antagonist, resatorvid (TAK-242), is a novel prototype chemo preventive agent that suppresses the production of inflammation mediators induced by UV exposure. This study aimed to design and develop TAK-242 into topical formulations using FDA-approved excipients, including DermaBaseTM, PENcreamTM, polyethylene glycol (PEG)-400, propylene glycol (PG), carbomer gel, hyaluronic acid (HA) gel, and Pluronic® F-127 poloxamer triblock copolymer gel for the prevention of skin cancer. The physicochemical properties of raw TAK-242, which influence the compatibility and solubility in the selected base materials, were confirmed using X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), hot-stage microscopy (HSM), Raman spectroscopy, and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopic analysis. The permeation behavior of TAK-242 from the prepared formulations was determined using Strat-M® transdermal diffusion membranes, and 3D cultured primary human-derived epidermal keratinocytes (EpiDermTM). Despite TAK-242′s high molecular weight and hydrophobicity, it can permeate through reconstructed human epidermis from all formulations. The findings, reported for the first time in this study, emphasize the capabilities of the topical application of TAK-242 via these multiple innovative topical drug delivery formulation platforms.
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Affiliation(s)
- Victor H. Ruiz
- Department of Pharmacology and Toxicology, The University of Arizona College of Pharmacy, Tucson, AZ 85721, USA; (V.H.R.); (D.E.-B.); (B.S.); (B.B.E.); (G.T.W.)
| | - David Encinas-Basurto
- Department of Pharmacology and Toxicology, The University of Arizona College of Pharmacy, Tucson, AZ 85721, USA; (V.H.R.); (D.E.-B.); (B.S.); (B.B.E.); (G.T.W.)
| | - Bo Sun
- Department of Pharmacology and Toxicology, The University of Arizona College of Pharmacy, Tucson, AZ 85721, USA; (V.H.R.); (D.E.-B.); (B.S.); (B.B.E.); (G.T.W.)
| | - Basanth Babu Eedara
- Department of Pharmacology and Toxicology, The University of Arizona College of Pharmacy, Tucson, AZ 85721, USA; (V.H.R.); (D.E.-B.); (B.S.); (B.B.E.); (G.T.W.)
- Center for Translational Science, Florida Interational University, Port St. Lucie, FL 34987, USA
| | - Sally E. Dickinson
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ 85724, USA; (S.E.D.); (H.-H.S.C.); (C.C.-L.)
- Department of Pharmacology, The University of Arizona College of Medicine, Tucson, AZ 85724, USA
| | - Georg T. Wondrak
- Department of Pharmacology and Toxicology, The University of Arizona College of Pharmacy, Tucson, AZ 85721, USA; (V.H.R.); (D.E.-B.); (B.S.); (B.B.E.); (G.T.W.)
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ 85724, USA; (S.E.D.); (H.-H.S.C.); (C.C.-L.)
| | - H. -H. Sherry Chow
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ 85724, USA; (S.E.D.); (H.-H.S.C.); (C.C.-L.)
- Department of Medicine, Division of Hematology and Oncology, The University of Arizona College of Medicine, Tucson, AZ 85724, USA
| | - Clara Curiel-Lewandrowski
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ 85724, USA; (S.E.D.); (H.-H.S.C.); (C.C.-L.)
- Department of Medicine, Division of Dermatology, The University of Arizona College of Medicine, Tucson, AZ 85724, USA
- BIO5 Institute, University of Arizona, Tucson, AZ 85724, USA
| | - Heidi M. Mansour
- Department of Pharmacology and Toxicology, The University of Arizona College of Pharmacy, Tucson, AZ 85721, USA; (V.H.R.); (D.E.-B.); (B.S.); (B.B.E.); (G.T.W.)
- Center for Translational Science, Florida Interational University, Port St. Lucie, FL 34987, USA
- BIO5 Institute, University of Arizona, Tucson, AZ 85724, USA
- Department of Medicine, Division of Translational & Regenerative Medicine, The University of Arizona College of Medicine, Tucson, AZ 85724, USA
- Correspondence: ; Tel.: +1-772-345-4731
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5
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Zhang J, Wang C, Wang H, Li X, Xu J, Yu K. Loganin alleviates sepsis-induced acute lung injury by regulating macrophage polarization and inhibiting NLRP3 inflammasome activation. Int Immunopharmacol 2021; 95:107529. [PMID: 33744777 DOI: 10.1016/j.intimp.2021.107529] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 02/21/2021] [Accepted: 02/22/2021] [Indexed: 10/21/2022]
Abstract
Sepsis is a systemic inflammatory response syndrome resulted from severe infection. Excessive inflammation response plays an important role in sepsis-induced acute lung injury (ALI). Loganin is an iridoid glycoside isolated from Corni fructus and exerts an anti-inflammatory effect in multiple inflammatory diseases; however, the role of loganin in sepsis-induced ALI remains unknown. In the current study, the cecal ligation and puncture (CLP)-induced murine sepsis model was constructed to investigate the anti-inflammatory property of loganin in sepsis-induced ALI. Lipopolysaccharide (LPS)-treated Raw 264.7 cells and primary murine peritoneal macrophages were established to further explore underlying mechanism of loganin. Results showed that intragastrical administration of loganin significantly increased murine survival, reduced the alveolar structure damage and inflammatory cell infiltration. Loganin suppressed the release of the M1 macrophage-associated pro-inflammatory cytokines and induced the activation of M2-type anti-inflammatory cytokines. Besides, loganin dramatically inhibited NLRP3 inflammasome-mediated caspase-1 activation and subsequent IL-1β secretion. Further in vitro studies confirmed that loganin efficiently inhibited M1 macrophage polarization and NLRP3 inflammasome activation by blocking the extra-cellular signal-regulated kinase (ERK) and nuclear factor-kappa B (NF-κB) pathways. Taken together, the anti-inflammatory effect of loganin in sepsis-induced ALI was associated with the ERK and NF-κB pathway-mediated macrophage polarization and NLRP3 inflammasome activation. Our study offers a favorable mechanistic basis to support the therapeutic potential of loganin in anti-inflammatory diseases, such as sepsis-induced ALI.
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Affiliation(s)
- Jin Zhang
- Department of Critical Care Medicine, The First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Changsong Wang
- Department of Critical Care Medicine, Harbin Medical University Cancer Hospital, Harbin Medical University, Harbin, Heilongjiang 150081, China
| | - Hongliang Wang
- Department of Critical Care Medicine, The Second Affiliated Hospital of Harbin Medical University, Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Xueting Li
- Department of Critical Care Medicine, Harbin Medical University Cancer Hospital, Harbin Medical University, Harbin, Heilongjiang 150081, China
| | - Jingjing Xu
- Department of Critical Care Medicine, Harbin Medical University Cancer Hospital, Harbin Medical University, Harbin, Heilongjiang 150081, China
| | - Kaijiang Yu
- Department of Critical Care Medicine, The First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Harbin, Heilongjiang 150001, China.
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Mohammed ET, Safwat GM. Grape Seed Proanthocyanidin Extract Mitigates Titanium Dioxide Nanoparticle (TiO 2-NPs)-Induced Hepatotoxicity Through TLR-4/NF-κB Signaling Pathway. Biol Trace Elem Res 2020; 196:579-589. [PMID: 31701464 DOI: 10.1007/s12011-019-01955-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 10/24/2019] [Indexed: 01/01/2023]
Abstract
With the progress of nanotechnology, the adverse effects of nanoscale materials are receiving much attention. Inhibition of toll-like receptor 4 (TLR-4)/nuclear factor kappa B (NF-κB) signaling is a hallmark for downregulating the expression of many inflammatory genes implicated in oxidative stress. Therefore, the present study aimed to demonstrate the influence of grape seed proanthocyanidin extract (GSE) on the hepatic TLR-4/ NF-κB signaling pathway in TiO2-NP-induced liver damage in rats. Forty male Albino rats were divided into 4 groups (n = 10): G1 was used as a control, G2 received TiO2-NPs (500 mg/kg/day orally) from the 17th to 30th day (acute toxicity), G3 received GSE (75 mg/kg/day orally) for 30 days, and G4 pre- and co-treated with GSE (for 30 days) and TiO2-NPs (from the 17th to 30th day), with the aforementioned doses. TiO2-NPs induced severe hepatic injury that was indicated by biochemical alterations in serum liver markers (acetylcholinesterase, ALT, ALP, total proteins, albumin, and direct bilirubin), oxidative stress indicators (MDA, GSH, and catalase), and histopathological alterations as well. Moreover, TiO2-NPs triggered an inflammatory response via the upregulation of TLR-4, NF-κB, NIK, and TNF-α mRNA expressions. Pre- and co-treatments with GSE alleviated the detrimental effects of TiO2-NPs which were enforced by the histopathological improvements. These results indicated that GSE effectively protected against TiO2-NP-induced hepatotoxicity via the inhibition of TLR-4/NF-κB signaling and hence suppressed the production of pro inflammatory cytokines such as TNF-α and improved the antioxidant status of the rats.
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Affiliation(s)
- Eman T Mohammed
- Department of Biochemistry, Faculty of Veterinary Medicine, Beni-Suef University, Beni Suef, Egypt.
| | - Ghada M Safwat
- Department of Biochemistry, Faculty of Veterinary Medicine, Beni-Suef University, Beni Suef, Egypt
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Mokhtari-Zaer A, Norouzi F, Askari VR, Khazdair MR, Roshan NM, Boskabady M, Hosseini M, Boskabady MH. The protective effect of Nigella sativa extract on lung inflammation and oxidative stress induced by lipopolysaccharide in rats. JOURNAL OF ETHNOPHARMACOLOGY 2020; 253:112653. [PMID: 32035219 DOI: 10.1016/j.jep.2020.112653] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 02/01/2020] [Accepted: 02/04/2020] [Indexed: 05/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Oxidative stress during inflammation can increase inflammation and damage tissue. Nigella sativa L. (NS) showed many pharmacological properties including antioxidant and anti-inflammatory activities. AIM OF THE STUDY In this study, the preventive effect of NS on lung inflammation and oxidative stress induced by lipopolysaccharide (LPS) in the rats was investigated. MATERIALS AND METHODS Male rats were assigned to: Control, LPS (1 mg/kg, i.p.), LPS + NS (100, 200, 400 mg/kg, i.p.), (10 per group). Saline (1 ml/kg) was intra-peritoneal (i.p.) injected instead of LPS in the rats of the control group. LPS dissolved in saline and injected i.p. daily for 14 days. Treatment with NS extracts started two days before LPS administration and treatment continued during LPS administration. White blood cells (WBC), total and differential as well as oxidative stress index in bronchoalveolar fluid (BALF) and serum, TGF-β1, IFN-γ, PGE2, and IL-4 levels in the BALF and lung histopathology were examined. RESULTS LPS administration increased total WBC, eosinophils, neutrophils, basophils, and monocytes counts as well as oxidative stress markers in the BALF and serum as well as TGF-β1, IFN-γ, PGE2, IL-4 levels in the BALF and pathological changes of the lung tissue. All of these effects were reduced by NS extract treatment dose-dependently. CONCLUSION These results suggested the protective effects of NS extract on lung inflammation and oxidative stress as well as its effect on lung pathology induced by LPS dose-dependently.
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Affiliation(s)
- Amin Mokhtari-Zaer
- Pharmaceutical Sciences Research Center, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Fatemeh Norouzi
- Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Vahid Reza Askari
- Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Pharmacological Research Center of Medicinal Plants, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Pharmacology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad Reza Khazdair
- Cardiovascular Diseases Research Center, Birjand University of Medical Sciences, Birjand, Iran
| | - Nama Mohammadian Roshan
- Department of Pathology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mostafa Boskabady
- Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mahmoud Hosseini
- Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Division of Neurocognitive Sciences, Psychiatry and Behavioral Sciences Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad Hossein Boskabady
- Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
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Vural A, Nabar NR, Hwang IY, Sohn S, Park C, Karlsson MCI, Blumer JB, Kehrl JH. Gα i2 Signaling Regulates Inflammasome Priming and Cytokine Production by Biasing Macrophage Phenotype Determination. THE JOURNAL OF IMMUNOLOGY 2019; 202:1510-1520. [PMID: 30683698 DOI: 10.4049/jimmunol.1801145] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 12/19/2018] [Indexed: 12/14/2022]
Abstract
Macrophages exist as innate immune subsets that exhibit phenotypic heterogeneity and functional plasticity. Their phenotypes are dictated by inputs from the tissue microenvironment. G-protein-coupled receptors are essential in transducing signals from the microenvironment, and heterotrimeric Gα signaling links these receptors to downstream effectors. Several Gαi-coupled G-protein-coupled receptors have been implicated in macrophage polarization. In this study, we use genetically modified mice to investigate the role of Gαi2 on inflammasome activity and macrophage polarization. We report that Gαi2 in murine bone marrow-derived macrophages (BMDMs) regulates IL-1β release after activation of the NLRP3, AIM2, and NLRC4 inflammasomes. We show this regulation stems from the biased polarity of Gαi2 deficient (Gnai2 -/-) and RGS-insensitive Gαi2 (Gnai2 G184S/G184S) BMDMs. We determined that although Gnai2 G184S/G184S BMDMs (excess Gαi2 signaling) have a tendency toward classically activated proinflammatory (M1) phenotype, Gnai2-/- BMDMs (Gαi2 deficient) are biased toward alternatively activated anti-inflammatory (M2) phenotype. Finally, we find that Gαi2-deficient macrophages have increased Akt activation and IFN-β production but defects in ERK1/2 and STAT3 activation after LPS stimulation. Gαi2-deficient macrophages also exhibit increased STAT6 activation after IL-4 stimulation. In summary, our data indicates that excess Gαi2 signaling promotes an M1 macrophage phenotype, whereas Gαi2 signaling deficiency promotes an M2 phenotype. Understanding Gαi2-mediated effects on macrophage polarization may bring to light insights regarding disease pathogenesis and the reprogramming of macrophages for the development of novel therapeutics.
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Affiliation(s)
- Ali Vural
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Neel R Nabar
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892; .,Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 171 77 Stockholm, Sweden; and
| | - Il-Young Hwang
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Silke Sohn
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 171 77 Stockholm, Sweden; and
| | - Chung Park
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Mikael C I Karlsson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 171 77 Stockholm, Sweden; and
| | - Joe B Blumer
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425
| | - John H Kehrl
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892;
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Dickinson SE, Wondrak GT. TLR4-directed Molecular Strategies Targeting Skin Photodamage and Carcinogenesis. Curr Med Chem 2019; 25:5487-5502. [DOI: 10.2174/0929867324666170828125328] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/30/2017] [Accepted: 06/30/2017] [Indexed: 01/16/2023]
Abstract
Background:
Exposure to solar ultraviolet (UV) radiation is a causative factor in
skin photodamage and carcinogenesis, and inflammatory dysregulation is a key mechanism
underlying detrimental effects of acute and chronic UV exposure. The health and economic
burden of skin cancer treatment is substantial, creating an increasingly urgent need for the development
of improved molecular strategies for photoprotection and photochemoprevention.
Methods:
A structured search of bibliographic databases for peer-reviewed research literature
revealed 139 articles including our own that are presented and critically evaluated in this
TLR4-directed review.
Objective:
To understand the molecular role of Toll-like receptor 4 (TLR4) as a key regulator
of skin anti-microbial defense, wound healing, and cutaneous tumorigenic inflammation. The
specific focus of this review is on recent published evidence suggesting that TLR4 represents
a novel molecular target for skin photoprotection and cancer photochemoprevention.
Results:
Cumulative experimental evidence indicates that pharmacological and genetic antagonism
of TLR4 suppresses UV-induced inflammatory signaling involving the attenuation
of cutaneous NF-κB and AP-1 stress signaling observable in vitro and in vivo. TLR4-directed
small molecule pharmacological antagonists [including eritoran, (+)-naloxone, ST2825, and
resatorvid] have now been identified as a novel class of molecular therapeutics. TLR4 antagonists
are in various stages of preclinical and clinical development for the modulation of
dysregulated TLR4-dependent inflammatory signaling that may also contribute to skin photodamage
and photocarcinogenesis in human populations.
Conclusion:
Future research should explore the skin photoprotective and photochemopreventive
efficacy of topical TLR4 antagonism if employed in conjunction with other molecular
strategies including sunscreens.
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Affiliation(s)
- Sally E. Dickinson
- Department of Pharmacology, College of Medicine and The University of Arizona Cancer Center, University of Arizona, Tucson, AZ 85724, United States
| | - Georg T. Wondrak
- Department of Pharmacology and Toxicology, College of Pharmacy and The University of Arizona Cancer Center, University of Arizona, Tucson, AZ 85724, United States
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Alqinyah M, Almutairi F, Wendimu MY, Hooks SB. RGS10 Regulates the Expression of Cyclooxygenase-2 and Tumor Necrosis Factor Alpha through a G Protein-Independent Mechanism. Mol Pharmacol 2018; 94:1103-1113. [PMID: 30049816 DOI: 10.1124/mol.118.111674] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 07/11/2018] [Indexed: 01/18/2023] Open
Abstract
The small regulator of G protein signaling protein RGS10 is a key regulator of neuroinflammation and ovarian cancer cell survival; however, the mechanism for RGS10 function in these cells is unknown and has not been linked to specific G protein pathways. RGS10 is highly enriched in microglia, and loss of RGS10 expression in microglia amplifies production of the inflammatory cytokine tumor necrosis factor α (TNFα) and enhances microglia-induced neurotoxicity. RGS10 also regulates cell survival and chemoresistance of ovarian cancer cells. Cyclooxygenase-2 (COX-2)-mediated production of prostaglandins such as prostaglandin E2 (PGE2) is a key factor in both neuroinflammation and cancer chemoresistance, suggesting it may be involved in RGS10 function in both cell types, but a connection between RGS10 and COX-2 has not been reported. To address these questions, we completed a mechanistic study to characterize RGS10 regulation of TNFα and COX-2 and to determine if these effects are mediated through a G protein-dependent mechanism. Our data show for the first time that loss of RGS10 expression significantly elevates stimulated COX-2 expression and PGE2 production in microglia. Furthermore, the elevated inflammatory signaling resulting from RGS10 loss was not affected by Gαi inhibition, and a RGS10 mutant that is unable to bind activated G proteins was as effective as wild type in inhibiting TNFα expression. Similarly, suppression of RGS10 in ovarian cancer cells enhanced TNFα and COX-2 expression, and this effect did not require Gi activity. Together, our data strongly indicate that RGS10 inhibits COX-2 expression by a G protein-independent mechanism to regulate inflammatory signaling in microglia and ovarian cancer cells.
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Affiliation(s)
- Mohammed Alqinyah
- Hooks Laboratory, Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia
| | - Faris Almutairi
- Hooks Laboratory, Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia
| | - Menbere Y Wendimu
- Hooks Laboratory, Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia
| | - Shelley B Hooks
- Hooks Laboratory, Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia
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Effects of Glycyrrhizin on the Differentiation of Myeloid Cells of the Heart and Lungs in Lipopolysaccharide-Induced Septic Mice. Shock 2018; 48:371-376. [PMID: 28221243 DOI: 10.1097/shk.0000000000000850] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND This study investigated the effects of glycyrrhizin (GR) on the ratio of myeloid-derived suppressor cells (MDSCs) to cluster of differentiation (CD)11b+Gr1 myeloid cells in the heart and lungs in lipopolysaccharide (LPS)-induced septic mice. METHODS Mice were divided into three groups: Control, LPS, and LPS+GR. After intraperitoneal injection of phosphate-buffered saline for the Control group, LPS for the LPS group, and a combination of LPS and GR for the LPS+GR group, fluorescence-activated cell sorting was utilized to evaluate cytokines and immune cells in the blood, heart, and lungs. Histopathologic analysis of Toll-like receptor (TLR)4 was also performed. RESULTS The cytokine amounts in the LPS and LPS+GR groups were significantly higher than in the Control group; however, that in the LPS+GR group was significant lower than in the LPS group. The ratio of MDSCs to CD11b+Gr1 myeloid cells in the LPS+GR group was significantly higher than in the LPS group but was significantly lower than in the Control group. The staining intensity of TLR4 showed the same pattern as that of cytokines in the heart and lungs. TLR4 staining was significantly lower in the LPS+GR group than in the LPS group but was higher than that in the Control group. CONCLUSION GR exhibited protective effects on the heart and lungs in LPS-induced septic mice. The effects were associated with an elevated ratio of MDSCs to CD11b+Gr1 myeloid cells and the inhibition of cytokine release and TLR4 expression after GR injection.
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Liver nitrosation and inflammation in septic rats were suppressed by propofol via downregulating TLR4/NF-κB-mediated iNOS and IL-6 gene expressions. Life Sci 2018; 195:25-32. [DOI: 10.1016/j.lfs.2018.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 12/11/2017] [Accepted: 01/03/2018] [Indexed: 01/23/2023]
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13
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Zhang QH, Hao JW, Li GL, Ji XJ, Yao XD, Dong N, Yao YM. Proinflammatory switch from Gαs to Gαi signaling by Glucagon-like peptide-1 receptor in murine splenic monocyte following burn injury. Inflamm Res 2017; 67:157-168. [PMID: 29022064 DOI: 10.1007/s00011-017-1104-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 09/26/2017] [Accepted: 09/30/2017] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVE Glucagon-like peptide-1 (GLP-1)-based therapy via G protein-coupled receptor (GPCR) GLP-1R, to attenuate hyperglycemia in critical care has attracted great attention. However, the exaggerated inflammation by GLP-1R agonist, Exendin-4, in a mouse model of burn injury was quite unexpected. Recent studies found that GPCR might elicit proinflammatory effects by switching from Gαs to Gαi signaling in the immune system. Thus, we aimed to investigate the possible Gαs to Gαi switch in GLP-1R signaling in monocyte following burn injury. MATERIALS AND METHODS Splenic monocytes from sham and burn mice 24 h following burn injury were treated with consecutive doses of Exendin-4 alone or in combination with an inhibitor of Gαi signaling (pertussis toxin, PTX), or a blocker of protein kinase A (H89). Cell viability was assessed by CCK-8, and the supernatant was collected for cytokine measurement by ELISA. Intracellular cAMP level, phosphorylated PKA activity, and nuclear NF-κB p65 were determined by ELISA, ERK1/2 activation was analyzed by Western blot. The expression of GLP-1R downstream molecules, Gαs, Gαi and G-protein coupled receptor kinase 2 (GRK2) were examined by immunofluorescence staining and Western blot. RESULTS Exendin-4 could inhibit the viability of monocyte from sham rather than burn mice. Unexpectedly, it could also reduce TNF-α secretion from sham monocyte while increase it from burn monocyte. The increased secretion of TNF-α by Exendin-4 from burn monocyte could be reversed by pretreatment of PTX or H89. Accordingly, Exendin-4 could stimulates cAMP production dose dependently from sham instead of burn monocyte. However, the blunt cAMP production from burn monocyte was further suppressed by pretreatment of PTX or H89 after 6-h incubation. Nevertheless, phosphorylated PKA activity was significantly increased by low dose of Exendin-4 in sham monocyte, by contrast, it was enhanced by high dose of Exendin-4 in burn monocyte after 1-h incubation. Following Exendin-4 treatment for 2 h ex vivo, total nuclear NF-κB and phosphorylated NF-κB activity, as well as cytoplasmic pERK1/2 expressions were reduced in sham monocyte, however, only pERK1/2 was increased by Exendin-4 in burn monocytes. Moreover, reduced expressions of GLP-1R, GRK-2 and Gαs in contrast with increased expression of Gαi were identified in burn monocyte relative to sham monocyte. CONCLUSIONS This study presents an unexpected proinflammatory switch from Gαs to Gαi signaling in burn monocyte, which promotes ERK1/2 and NF-κB activation and the downstream TNF-α secretion. This phenomenon is most probably responsible for proinflammatory response evoked by Gαs agonist Exendin-4 following burn injury.
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Affiliation(s)
- Qing-Hong Zhang
- Department of Microbiology and Immunology, Burns' Institute, First Hospital Affiliated to the Chinese PLA General Hospital, 51 Fucheng Road, Haidian District, Beijing, 100048, People's Republic of China.
| | - Ji-Wei Hao
- Department of Microbiology and Immunology, Burns' Institute, First Hospital Affiliated to the Chinese PLA General Hospital, 51 Fucheng Road, Haidian District, Beijing, 100048, People's Republic of China
| | - Guang-Lei Li
- Department of Microbiology and Immunology, Burns' Institute, First Hospital Affiliated to the Chinese PLA General Hospital, 51 Fucheng Road, Haidian District, Beijing, 100048, People's Republic of China
| | - Xiao-Jing Ji
- Department of Emergency, First Hospital Affiliated to Wenzhou Medical College, Wenzhou, 325000, People's Republic of China
| | - Xu-Dong Yao
- Department of Emergency, First Hospital Affiliated to Wenzhou Medical College, Wenzhou, 325000, People's Republic of China
| | - Ning Dong
- Department of Microbiology and Immunology, Burns' Institute, First Hospital Affiliated to the Chinese PLA General Hospital, 51 Fucheng Road, Haidian District, Beijing, 100048, People's Republic of China
| | - Yong-Ming Yao
- Department of Microbiology and Immunology, Burns' Institute, First Hospital Affiliated to the Chinese PLA General Hospital, 51 Fucheng Road, Haidian District, Beijing, 100048, People's Republic of China. .,State Key Laboratory of Kidney Disease, The Chinese PLA General Hospital, Beijing, 100853, People's Republic of China.
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Chitosan nanoparticles reduce LPS-induced inflammatory reaction via inhibition of NF-κB pathway in Caco-2 cells. Int J Biol Macromol 2016; 86:848-56. [PMID: 26854884 DOI: 10.1016/j.ijbiomac.2016.02.015] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 01/31/2016] [Accepted: 02/03/2016] [Indexed: 12/24/2022]
Abstract
Chitosan nanoparticles (CNP), an extensively oral-administered drug carrier, was investigated for the anti-inflammatory effects on LPS-inflamed Caco-2 cells and the relate mechanisms. CNP could alleviate the decrease of transepithelial electrical resistance (TEER) induced by LPS in Caco-2 monolayer, and significantly inhibit LPS-induced production of TNF-α, MIF, IL-8 and MCP-1 in a dose-dependent manner. PCR array assay revealed that CNP down-regulated the mRNA expression levels of TLR4 in LPS-inflamed Caco-2 cells. CNP was further showed to reduce cytoplasmic IκB-α degradation and nuclear NF-κB p65 levels in LPS-inflamed Caco-2 cells. These results suggested that CNP suppressed LPS-induced inflammatory response by decreasing permeability of intestinal epithelial monolayer and secretion of pro-inflammatory cytokine in Caco-2 cells, which were partially mediated by NF-κB signaling pathway.
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Hong F, Wang Y, Zhou Y, Zhang Q, Ge Y, Chen M, Hong J, Wang L. Exposure to TiO2 Nanoparticles Induces Immunological Dysfunction in Mouse Testitis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:346-55. [PMID: 26720763 DOI: 10.1021/acs.jafc.5b05262] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Although TiO2 nanoparticles (NPs) as endocrine disruptors have been demonstrated to be able to cross the blood-testis barriers and induce reproductive toxicity in male animals, whether the reproductive toxicity of male animals due to exposure to endocrine disruptor TiO2 NPs is related to immunological dysfunction in the testis remains not well understood. This study determined whether the reproductive toxicity and immunological dysfunction induced by exposure to TiO2 NPs is associated with activation or inhibition of TAM/TLR-mediated signal pathway in mouse testis. The results showed that male mice exhibited significant reduction of fertility, infiltration of inflammatory cells, rarefaction, apoptosis, and/or necrosis of spermatogenic cells and Sertoli cells due to TiO2 NPs. Furthermore, these were associated with decreased expression of Tyro3 (-18.16 to -66.6%), Axl (-14.7 to -57.99%), Mer (-7.98 to -72.62%), and IκB (-11.25 to -63.16%), suppression of cytokine signaling (SOCS) 1 (-21.99 to -73.8%) and SOCS3 (-8.11 to -34.86%), and increased expression of Toll-like receptor (TLR)-3 (21.4-156.03%), TLR-4 (37.0-109.87%), nuclear factor-κB (14.75-69.34%), interleukin (IL)-lβ (46.15-123.08%), IL-6 (2.54-81.98%), tumor necrosis factor-α (6.95-88.39%), interferon (IFN)-α (2.54-37.25%), and IFN-β (10.19-80.56%), which are involved in the immune environment in the testis. The findings showed that reproductive toxicity of male mice induced by exposure to endocrine disruptor TiO2 NPs may be associated with biomarkers of impairment of immune environment or dysfunction of TAM/TLR3-mediated signal pathway in mouse testitis. Therefore, the potential risks to reproductive health should be attended, especially in those who are occupationally exposed to TiO2 NPs.
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Affiliation(s)
- Fashui Hong
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University , Huaian 223300, China
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Huaiyin Normal University , Huaian 223300, China
- School of Life Sciences, Huaiyin Normal University , Huaian 223300, China
| | - Yajing Wang
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University , Huaian 223300, China
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Huaiyin Normal University , Huaian 223300, China
- School of Life Sciences, Huaiyin Normal University , Huaian 223300, China
| | - Yingjun Zhou
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University , Huaian 223300, China
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Huaiyin Normal University , Huaian 223300, China
- School of Life Sciences, Huaiyin Normal University , Huaian 223300, China
| | - Qi Zhang
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University , Huaian 223300, China
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Huaiyin Normal University , Huaian 223300, China
- School of Life Sciences, Huaiyin Normal University , Huaian 223300, China
| | - Yushuang Ge
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University , Huaian 223300, China
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Huaiyin Normal University , Huaian 223300, China
- School of Life Sciences, Huaiyin Normal University , Huaian 223300, China
| | - Ming Chen
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University , Huaian 223300, China
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Huaiyin Normal University , Huaian 223300, China
- School of Life Sciences, Huaiyin Normal University , Huaian 223300, China
| | - Jie Hong
- Medical College of Soochow University , Suzhou 215123, China
| | - Ling Wang
- Library of Soochow University , Suzhou 215123, China
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Karassek S, Starost L, Solbach J, Greune L, Sano Y, Kanda T, Kim K, Schmidt MA. Pertussis Toxin Exploits Specific Host Cell Signaling Pathways for Promoting Invasion and Translocation of Escherichia coli K1 RS218 in Human Brain-derived Microvascular Endothelial Cells. J Biol Chem 2015; 290:24835-43. [PMID: 26324705 DOI: 10.1074/jbc.m115.650101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Indexed: 01/23/2023] Open
Abstract
Pertussis toxin (PTx), an AB5 toxin and major virulence factor of the whooping cough-causing pathogen Bordetella pertussis, has been shown to affect the blood-brain barrier. Dysfunction of the blood-brain barrier may facilitate penetration of bacterial pathogens into the brain, such as Escherichia coli K1 (RS218). In this study, we investigated the influence of PTx on blood-brain barrier permissiveness to E. coli infection using human brain-derived endothelial HBMEC and TY10 cells as in vitro models. Our results indicate that PTx acts at several key points of host cell intracellular signaling pathways, which are also affected by E. coli K1 RS218 infection. Application of PTx increased the expression of the pathogen binding receptor gp96. Further, we found an activation of STAT3 and of the small GTPase Rac1, which have been described as being essential for bacterial invasion involving host cell actin cytoskeleton rearrangements at the bacterial entry site. In addition, we showed that PTx induces a remarkable relocation of VE-cadherin and β-catenin from intercellular junctions. The observed changes in host cell signaling molecules were accompanied by differences in intracellular calcium levels, which might act as a second messenger system for PTx. In summary, PTx not only facilitates invasion of E. coli K1 RS218 by activating essential signaling cascades; it also affects intercellular barriers to increase paracellular translocation.
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Affiliation(s)
- Sascha Karassek
- From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany
| | - Laura Starost
- From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany
| | - Johanna Solbach
- From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany
| | - Lilo Greune
- From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany
| | - Yasuteru Sano
- the Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan, and
| | - Takashi Kanda
- the Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan, and
| | - KwangSik Kim
- the Pediatric Infectious Diseases Division, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | - M Alexander Schmidt
- From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany,
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Gαi1 and Gαi3 regulate macrophage polarization by forming a complex containing CD14 and Gab1. Proc Natl Acad Sci U S A 2015; 112:4731-6. [PMID: 25825741 DOI: 10.1073/pnas.1503779112] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Heterotrimeric G proteins have been implicated in Toll-like receptor 4 (TLR4) signaling in macrophages and endothelial cells. However, whether guanine nucleotide-binding protein G(i) subunit alpha-1 and alpha-3 (Gαi1/3) are required for LPS responses remains unclear, and if so, the underlying mechanisms need to be studied. In this study, we demonstrated that, in response to LPS, Gαi1/3 form complexes containing the pattern recognition receptor (PRR) CD14 and growth factor receptor binding 2 (Grb2)-associated binding protein (Gab1), which are required for activation of PI3K-Akt signaling. Gαi1/3 deficiency decreased LPS-induced TLR4 endocytosis, which was associated with decreased phosphorylation of IFN regulatory factor 3 (IRF3). Gαi1/3 knockdown in bone marrow-derived macrophage cells (Gαi1/3 KD BMDMs) exhibited an M2-like phenotype with significantly suppressed production of TNF-α, IL-6, IL-12, and NO in response to LPS. The altered polarization coincided with decreased Akt activation. Further, Gαi1/3 deficiency caused LPS tolerance in mice. In vitro studies revealed that, in LPS-tolerant macrophages, Gαi1/3 were down-regulated partially by the proteasome pathway. Collectively, the present findings demonstrated that Gαi1/3 can interact with CD14/Gab1, which modulates macrophage polarization in vitro and in vivo.
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Axente E, Sima F, Elena Sima L, Erginer M, Eroglu MS, Serban N, Ristoscu C, Petrescu SM, Toksoy Oner E, Mihailescu IN. Combinatorial MAPLE gradient thin film assemblies signalling to human osteoblasts. Biofabrication 2014; 6:035010. [DOI: 10.1088/1758-5082/6/3/035010] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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19
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Ze Y, Sheng L, Zhao X, Hong J, Ze X, Yu X, Pan X, Lin A, Zhao Y, Zhang C, Zhou Q, Wang L, Hong F. TiO2 nanoparticles induced hippocampal neuroinflammation in mice. PLoS One 2014; 9:e92230. [PMID: 24658543 PMCID: PMC3962383 DOI: 10.1371/journal.pone.0092230] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 02/19/2014] [Indexed: 12/11/2022] Open
Abstract
Titanium dioxide nanoparticles (TiO2 NPs) have been used in various medical and industrial areas. However, the impacts of these nanoparticles on neuroinflammation in the brain are poorly understood. In this study, mice were exposed to 2.5, 5, or 10 mg/kg body weight TiO2 NPs for 90 consecutive days, and the TLRs/TNF-α/NF-κB signaling pathway associated with the hippocampal neuroinflammation was investigated. Our findings showed titanium accumulation in the hippocampus, neuroinflammation and impairment of spatial memory in mice following exposure to TiO2 NPs. Furthermore, TiO2 NPs significantly activated the expression of Toll-like receptors (TLR2, TLR4), tumor necrosis factor-α, nucleic IκB kinase, NF-κB-inducible kinase, nucleic factor-κB, NF-κB2(p52), RelA(p65), and significantly suppressed the expression of IκB and interleukin-2. These findings suggest that neuroinflammation may be involved in TiO2 NP-induced alterations of cytokine expression in mouse hippocampus. Therefore, more attention should be focused on the application of TiO2 NPs in the food industry and their long-term exposure effects, especially in the human central nervous system.
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Affiliation(s)
- Yuguan Ze
- Medical College of Soochow University, Suzhou, China
| | - Lei Sheng
- Medical College of Soochow University, Suzhou, China
| | - Xiaoyang Zhao
- Medical College of Soochow University, Suzhou, China
| | - Jie Hong
- Medical College of Soochow University, Suzhou, China
| | - Xiao Ze
- Medical College of Soochow University, Suzhou, China
| | - Xiaohong Yu
- Medical College of Soochow University, Suzhou, China
| | - Xiaoyu Pan
- Medical College of Soochow University, Suzhou, China
| | - Anan Lin
- Medical College of Soochow University, Suzhou, China
| | - Yue Zhao
- Medical College of Soochow University, Suzhou, China
| | - Chi Zhang
- Medical College of Soochow University, Suzhou, China
| | - Qiuping Zhou
- Medical College of Soochow University, Suzhou, China
| | - Ling Wang
- Medical College of Soochow University, Suzhou, China
| | - Fashui Hong
- Medical College of Soochow University, Suzhou, China
- Jiangsu Province Key Laboratory of Stem Cell Research, Soochow University, Suzhou, China
- Cultivation Base of State Key Laboratory of Stem Cell and Biomaterials Built Together by Ministry of Science and Technology and Jiangsu Province, Suzhou, China
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Wu TT, Tai YT, Cherng YG, Chen TG, Lin CJ, Chen TL, Chang HC, Chen RM. GATA-2 transduces LPS-induced il-1β gene expression in macrophages via a toll-like receptor 4/MD88/MAPK-dependent mechanism. PLoS One 2013; 8:e72404. [PMID: 23940812 PMCID: PMC3735524 DOI: 10.1371/journal.pone.0072404] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 07/10/2013] [Indexed: 12/15/2022] Open
Abstract
Lipopolysaccharide (LPS) is a critical factor for inducing acute lung injury. GATA-2, a transcription factor, contributes to the control of cell activity and function. Exposure of RAW 264.7 cells to LPS induced interleukin (IL)-1β mRNA and protein expression and GATA-2 translocation from the cytoplasm to nuclei in concentration- and time-dependent manners. A bioinformatic search revealed that GATA-2-specific binding elements exist in the 5'-promoter region of the il-1β gene. LPS could enhance the transactivation activity of GATA-2 in macrophages. Knocking-down translation of GATA-2 mRNA using RNA interference significantly alleviated LPS-induced IL-1β mRNA and protein expression. As to the mechanism, transfection of toll-like receptor (TLR) 4 small interfering (si)RNA into macrophages concurrently decreased LPS-caused increases in nuclear GATA-2 levels. Sequentially, treatment with myeloid differentiation factor 88 (MyD88) siRNA decreased LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs) kinase 1/2 and subsequent translocation of GATA-2. Reducing MAPK activities using specific inhibitors simultaneously decreased GATA-2 activation. Furthermore, exposure of primary macrophages to LPS significantly increased the transactivation activities of GATA-2 and IL-1β mRNA and protein expression. Transfection of GATA-2 siRNA inhibited LPS-induced IL-1β mRNA expression. Results of this study show that LPS induction of il-1β gene expression in macrophages is mediated by GATA-2 via activation of TLR4, MyD88, and MAPKs.
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Affiliation(s)
- Tsu-Tuan Wu
- Graduate Institute of Medical Sciences and Center of Excellent Cancer Research, Taipei Medical University, Taipei, Taiwan
- Section of Respiratory and Critical Care Medicine, Department of Internal Medicine, Taipei County Hospital, Taipei, Taiwan
| | - Yu-Ting Tai
- Department of Anesthesiology, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yih-Giun Cherng
- Department of Anesthesiology, Shuang-Ho Hospital, Taipei Medical University, Taipei, Taiwan
| | - Tyng-Guey Chen
- Department of Anesthesiology, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Chien-Ju Lin
- Graduate Institute of Medical Sciences and Center of Excellent Cancer Research, Taipei Medical University, Taipei, Taiwan
| | - Ta-Liang Chen
- Anesthetics and Toxicology Research Center, Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan
| | - Huai-Chia Chang
- Anesthetics and Toxicology Research Center, Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan
| | - Ruei-Ming Chen
- Graduate Institute of Medical Sciences and Center of Excellent Cancer Research, Taipei Medical University, Taipei, Taiwan
- Anesthetics and Toxicology Research Center, Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan
- Cell Physiology and Molecular Image Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan
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Li N, Cheng J, Cheng Z, Hu R, Cai J, Gao G, Cui Y, Wang L, Hong F. Molecular mechanism of inflammatory response in mouse liver caused by exposure to CeCl₃. ENVIRONMENTAL TOXICOLOGY 2013; 28:349-358. [PMID: 21656643 DOI: 10.1002/tox.20727] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2011] [Revised: 03/12/2011] [Accepted: 03/21/2011] [Indexed: 05/30/2023]
Abstract
To investigate the molecular mechanism of inflammatory response in the mouse liver caused by exposure to CeCl₃, we measured the liver indices, and cerium content, evaluated the liver histopathological section, detected serum biochemical parameters of liver function, and the immunoglobulin M (IgM) content, analyzed the liver mRNA and protein expression levels of Toll-like receptor 2, 4 (TLR2, TLR4), and inflammatory cytokines in liver using real-time quantitative reverse transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay. The results showed that exposure to CeCl₃ decreased body weight and caused cerium accumulation in the mouse liver and histopathological changes of liver (such as inflammatory cell infiltration). Furthermore, biochemical assays suggested that CeCl3 could promote the activities of alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase, pseudocholinesterase, and leucine aminopeptidase, decrease serum IgM, upregulate the levels of TLR2, TLR4, nuclear factor-κB (NF-κB), NF-κBp52, NF-κBp65, NF-κB-inducing kinase (NIK), IκB kinase α (IKK-α), IκB kinase β (IKK-β), and tumor necrosis factor-α (TNF-α) expression, and suppress NF-κB-inhibiting factor (IκB) and interleukin-2 (IL-2) expression in liver. Taken together, the inflammation of mice liver caused by exposure to CeCl₃ might be closely associated with the alteration of inflammatory cytokine expressions in the mouse liver, the signal-transducing events happening in CeCl₃-induced macrophages of liver sequentially might occur via activation of TLRs→TNF-α→NIK→IκB kinase (including IKK1, IKK2)→NF-κB (including NF-κBP52, NF-κBP65)→ inflammation.
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Affiliation(s)
- Na Li
- Medical College, Soochow University, Suzhou 215123, People's Republic of China
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Schoenfeld BP, Choi RJ, Choi CH, Terlizzi AM, Hinchey P, Kollaros M, Ferrick NJ, Koenigsberg E, Ferreiro D, Leibelt DA, Siegel SJ, Bell AJ, McDonald TV, Jongens TA, McBride SMJ. The Drosophila DmGluRA is required for social interaction and memory. Front Pharmacol 2013; 4:64. [PMID: 23720628 PMCID: PMC3662090 DOI: 10.3389/fphar.2013.00064] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 04/26/2013] [Indexed: 11/13/2022] Open
Abstract
Metabotropic glutamate receptors (mGluRs) have well-established roles in cognition and social behavior in mammals. Whether or not these roles have been conserved throughout evolution from invertebrate species is less clear. Mammals have eight mGluRs whereas Drosophila has a single DmGluRA, which has both Gi and Gq coupled signaling activity. We have utilized Drosophila to examine the role of DmGluRA in social behavior and various phases of memory. We have found that flies that are homozygous or heterozygous for loss of function mutations of DmGluRA have impaired social behavior in male Drosophila. Futhermore, flies that are heterozygous for loss of function mutations of DmGluRA have impaired learning during training, immediate-recall memory, short-term memory, and long-term memory as young adults. This work demonstrates a role for mGluR activity in both social behavior and memory in Drosophila.
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Affiliation(s)
- Brian P Schoenfeld
- Section of Molecular Cardiology, Department of Molecular Pharmacology and Medicine, Albert Einstein College of Medicine Bronx, NY, USA ; Department of Genetics, University of Pennsylvania School of Medicine Philadelphia, PA, USA
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Lichte P, Grigoleit JS, Steiner EM, Kullmann JS, Schedlowski M, Oberbeck R, Kobbe P. Low dose LPS does not increase TLR4 expression on monocytes in a human in vivo model. Cytokine 2013; 63:74-80. [PMID: 23673286 DOI: 10.1016/j.cyto.2013.04.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2012] [Revised: 04/04/2013] [Accepted: 04/11/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND AND PURPOSE Toll like receptor 4 (TLR4) is the major recognition receptor for lipopolysaccharides and plays a major role in the inflammatory response. CD11b is expressed on the surface of many leukocytes including monocytes. The CD11b/CD18 complex is involved in the inflammatory response by mediating migration and adhesion of leukocytes. The aim of this human in vivo study was to investigate the expression of TLR4 and CD11b on the surface of human monocytes after in vivo low-dose LPS stimulation. METHODS We performed a double-blind, randomized crossover study with 16 healthy males who received a bolus injection of bacterial lipopolysaccharide (LPS; 0.4ng/kg) or normal saline. Vital parameters, blood counts, serum cytokine levels, the expression of TLR4, and CD11b on CD14 positive cells were analyzed. RESULTS The experimentally induced inflammatory response was reflected by transient increases in body temperature, circulating leukocyte numbers, and plasma levels of pro- (TNF-α, IL-6) and anti-inflammatory cytokines (IL-10, IL-1ra). In contrast to a significant increase in CD11b expression, no changes in TLR4 expression on circulating monocytes were detectable. CONCLUSION Early changes in TLR4 expression on circulating monocytes are not necessarily part of the inflammatory response to low dose LPS in humans whereas the detected increase of CD11b expression might already be sufficient for optimized recognition and signalling.
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Affiliation(s)
- Philipp Lichte
- Department of Orthopaedic Trauma Surgery, Medical School of the RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany; Department of Trauma Surgery, University Essen Medical School, Hufelandstrasse 55, 45122 Essen, Germany.
| | - Jan-Sebastian Grigoleit
- Institute of Medical Psychology and Behavioral Immunobiology, University Essen Medical School, University of Duisburg-Essen, Hufelandstrasse 55, 45122 Essen, Germany.
| | - Eva Maria Steiner
- Department of Trauma Surgery, University Essen Medical School, Hufelandstrasse 55, 45122 Essen, Germany.
| | - Jennifer S Kullmann
- Institute of Medical Psychology and Behavioral Immunobiology, University Essen Medical School, University of Duisburg-Essen, Hufelandstrasse 55, 45122 Essen, Germany.
| | - Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, University Essen Medical School, University of Duisburg-Essen, Hufelandstrasse 55, 45122 Essen, Germany.
| | - Reiner Oberbeck
- Department of Orthopaedic Trauma Surgery, Medical School of the RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany.
| | - Philipp Kobbe
- Department of Orthopaedic Trauma Surgery, Medical School of the RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany; Department of Trauma Surgery, University Essen Medical School, Hufelandstrasse 55, 45122 Essen, Germany.
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Wang X, Su J, Zhu L, Guan N, Sang X, Ze Y, Zhao X, Sheng L, Gui S, Sun Q, Wang L, Hong F. Hippocampal damage and alterations of inflammatory cytokine expression in mice caused by exposure to cerium chloride. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2013; 64:545-53. [PMID: 23338948 DOI: 10.1007/s00244-012-9870-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 12/29/2012] [Indexed: 05/23/2023]
Abstract
Rare earth element (REE) exposure has been shown to induce central nerve system intoxication, but the molecular mechanisms by which this occurs are poorly understood. In this study, cerium (Ce), in the form of CeCl3, was administered by way of gavage to mice for 90 consecutive days, and cytokine expression, associated with neuroinflammation of hippocampus, as well as spatial memory were increased in mice. Significant Ce accumulation in hippocampus, which led to neuroinflammation and decreased spatial memory of mice, was observed. Furthermore, CeCl3 remarkably increased levels of Toll-like receptors 2 and 4, tumor necrosis factor-α, nucleic IκB kinase, factor-κB-inducible kinase, nucleic factor-κB, and p52 and p65 expression as well as significantly decreased levels of IκB and interleukin-2 expression. These results showed that neuroinflammation and damaged hippocampal function may be associated with CeCl3-induced neuerotoxicity. Our findings suggest the need for workers and consumers to exercise caution when handling REEs.
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Affiliation(s)
- Xiaochun Wang
- Medical College, Soochow University, Suzhou, 215123, China
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25
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Moghimpour Bijani F, Vallejo JG, Rezaei N. Toll-like receptor signaling pathways in cardiovascular diseases: challenges and opportunities. Int Rev Immunol 2013; 31:379-95. [PMID: 23083347 DOI: 10.3109/08830185.2012.706761] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Toll-like receptors (TLRs), a family of surface molecules, are involved in innate immune responses. Recent studies indicated that TLRs play a critical role in inflammatory responses to exogenous and endogenous triggers. This article focuses on probable effects of TLRs in the morbidity of cardiovascular events, e.g., ischemic reperfusion (I/R) injury and atherosclerosis. TLR2 and TLR4 have been shown to have the most fundamental role in promoting cytokine production and subsequent inflammatory damages in these states. Blockade of these receptors may be beneficial in both preventing the occurrence and decreasing the complications in cardiovascular events. However, controversies exist on the certainty of this beneficial effect; therefore, additional studies are needed.
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Affiliation(s)
- Faezeh Moghimpour Bijani
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
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Toll-like receptor-induced inflammatory cytokines are suppressed by gain of function or overexpression of Gα(i2) protein. Inflammation 2013; 35:1611-7. [PMID: 22581266 DOI: 10.1007/s10753-012-9476-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Previous studies have implicated a role of Gα(i) proteins as co-regulators of Toll-like receptor (TLR) activation. These studies largely derived from examining the effect of Gα(i) protein inhibitors or genetic deletion of Gα(i) proteins. However, the effect of increased Gα(i) protein function or Gα(i) protein expression on TLR activation has not been investigated. We hypothesized that gain of function or increased expression of Gα(i) proteins suppresses TLR2- and TLR4-induced inflammatory cytokines. Novel transgenic mice with genomic "knock-in" of a regulator of G protein signaling (RGS)-insensitive Gnai2 allele (Gα(i2)(G184S/G184S) ; GS/GS) were employed. These mice express essentially normal levels of Gα(i2) protein; however, the Gα(i2) is insensitive to its negative regulator RGS thus rendering more sustained Gα(i2) protein activation following ligand/receptor binding. In subsequent studies, we generated Raw 264.7 cells that stably overexpress Gα(i2) protein (Raw Gα(i2)). Peritoneal macrophages, splenocytes, and mouse embryonic fibroblasts (MEF) were isolated from WT and GS/GS mice and were stimulated with LPS, Pam3CSK4, or Poly (I:C). We also subjected WT and GS/GS mice to endotoxic shock (LPS, 25 mg/kg i.p.) and plasma tumor necrosis factor alpha (TNF-α) and interleukin (IL)-6 production were determined. We found that in vitro LPS and Pam3CSK4-induced TNF-α, and IL-6 production are decreased in macrophages from GS/GS mice compared with WT mice (p < 0.05). In vitro, LPS and Pam3CSK4 induced IL-6 production in splenocytes, and in vivo, LPS-induced IL-6 were suppressed in GS/GS mice. Poly (I:C)-induced TNF-α, and IL-6 in vitro demonstrated no difference between GS/GS mice and WT mice. LPS-induced IL-6 production was inhibited in MEFs from GS/GS mice similarly to macrophage and splenocytes. In parallel studies, Raw Gα(i2) cells also exhibit decreased TNF-α and IL-6 production in response to LPS and Pam3CSK4. These studies support our hypothesis that Gα(i2) proteins are novel negative regulators of TLR activation.
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Mechanisms of ketamine-induced immunosuppression. ACTA ACUST UNITED AC 2012; 50:172-7. [DOI: 10.1016/j.aat.2012.12.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Revised: 07/17/2012] [Accepted: 08/20/2012] [Indexed: 01/01/2023]
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Fan H, Wong D, Ashton SH, Borg KT, Halushka PV, Cook JA. Beneficial effect of a CXCR4 agonist in murine models of systemic inflammation. Inflammation 2012; 35:130-7. [PMID: 21274742 DOI: 10.1007/s10753-011-9297-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The chemokine CXC receptor 4 (CXCR4) is activated by stromal cell-derived factor (SDF-1α). CXCR4 may be part of a lipopolysaccharide (LPS) sensing co-clustering complex that modulates TLR4 activation and evidence suggest that SDF-1α can activate anti-inflammatory signaling pathways and suppress inflammation. In the present study we examined the hypothesis that the SDF-1α peptide analog and CXCR4 agonist CTCE-0214 is anti-inflammatory in three distinct models of murine systemic inflammation. Our findings demonstrate that CTCE-0214 in vivo significantly suppressed plasma tumor necrosis factor alpha (TNF-α) increases in acute endotoxemia and following zymosan-induced multiple organ dysfunction syndrome (MODS). In both models, CTCE-0214 did not suppress plasma increases in the anti-inflammatory cytokine interleukin (IL)-10. CTCE-0214 improved survival without antibiotics in a model of severe sepsis induced by cecal ligation and puncture (CLP). CTCE-0214 also decreased plasma increases in IL-6 but not TNF-α and IL-10 in response to CLP-induced inflammation. We demonstrated in a moderately severe model of CLP (one puncture) that IL-6 levels at 24 h were similar to sham controls. However in severe CLP (two punctures) plasma IL-6 levels were markedly elevated. Plasma SDF-1α levels varied inversely with the plasma IL-6. In addition to the beneficial effect of CTCE-0214 in these models of systemic inflammation in vivo, we also demonstrated that the analog dose dependently suppressed LPS-induced IL-6 production in bone marrow-derived macrophages. CTCE-0214 therefore may be beneficial in controlling inflammation sepsis and systemic inflammatory syndromes.
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Affiliation(s)
- Hongkuan Fan
- Department of Neuroscience, The Medical University of South Carolina, 173 Ashley Ave., Charleston, SC 29425, USA.
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29
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Dauphinee SM, Voelcker V, Tebaykina Z, Wong F, Karsan A. Heterotrimeric Gi/Go proteins modulate endothelial TLR signaling independent of the MyD88-dependent pathway. Am J Physiol Heart Circ Physiol 2011; 301:H2246-53. [PMID: 21949112 DOI: 10.1152/ajpheart.01194.2010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The innate immune recognition of bacterial lipopolysaccharide (LPS) is mediated by Toll-like receptor 4 (TLR4) and results in activation of proinflammatory signaling including NF-κB and MAPK pathways. Heterotrimeric G proteins have been previously implicated in LPS signaling in macrophages and monocytes. In the present study, we show that pertussis toxin sensitive heterotrimeric G proteins (Gα(i/o)) are involved in the activation of MAPK and Akt downstream of TLR2, TLR3, and TLR4 in endothelial cells. Gα(i/o) are also required for full activation of interferon signaling downstream of TLR3 and TLR4 but are not required for the activation of NF-κB. We find that Gα(i/o)-mediated activation of the MAPK is independent of the canonical MyD88, interleukin-1 receptor-associated kinase, and tumor necrosis factor receptor-associated factor 6 signaling cascade in LPS-stimulated cells. Taken together, the data presented here suggest that heterotrimeric G proteins are widely involved in TLR pathways along a signaling cascade that is distinct from MyD88-TRAF6.
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Abstract
Pertussis toxin, produced and secreted by the whooping cough agent Bordetella pertussis, is one of the most complex soluble bacterial proteins. It is actively secreted through the B. pertussis cell envelope by the Ptl secretion system, a member of the widespread type IV secretion systems. The toxin is composed of five subunits (named S1 to S5 according to their decreasing molecular weights) arranged in an A-B structure. The A protomer is composed of the enzymatically active S1 subunit, which catalyzes ADP-ribosylation of the α subunit of trimeric G proteins, thereby disturbing the metabolic functions of the target cells, leading to a variety of biological activities. The B oligomer is composed of 1S2:1S3:2S4:1S5 and is responsible for binding of the toxin to the target cell receptors and for intracellular trafficking via receptor-mediated endocytosis and retrograde transport. The toxin is one of the most important virulence factors of B. pertussis and is a component of all current vaccines against whooping cough.
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Affiliation(s)
- Camille Locht
- Inserm U1019, CNRS UMR8204, Center for Infection and Immunity of Lille, Institut Pasteur de Lille, Univ Lille Nord de France, France.
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31
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Fan H, Li P, Zingarelli B, Borg K, Halushka PV, Birnbaumer L, Cook JA. Heterotrimeric Gα(i) proteins are regulated by lipopolysaccharide and are anti-inflammatory in endotoxemia and polymicrobial sepsis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:466-72. [PMID: 21255617 DOI: 10.1016/j.bbamcr.2011.01.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 01/06/2011] [Accepted: 01/10/2011] [Indexed: 11/17/2022]
Abstract
Previous studies have implicated a role of heterotrimeric Gα(i) proteins in lipopolysaccharide (LPS)-induced inflammatory responses. We hypothesized that Toll-like receptor (TLR) signaling regulates Gα(i) proteins, which are anti-inflammatory in endotoxemia and polymicrobial sepsis. RAW 264.7 cells were stimulated with LPS and the Gα(i)-GTP protein complex was immunoprecipitated with a Gα(i) protein activation assay. In subsequent in vivo studies, the Gα(i) protein inhibitor pertussis toxin (PTx) or G(i) protein agonist mastoparan (MP-7) were administrated prior to endotoxemia. LPS-induced pro-inflammatory cytokines and mortality were determined. To examine the role of Gα(i2) in sepsis, Gα(i2) (-/-) and wildtype (WT) mice were subjected to cecal ligation and puncture (CLP) and monitored every 24 h for 120 h. Other mice were sacrificed 24 h after CLP. Peritoneal fluid, blood, and tissue samples were collected. Plasma pro-inflammatory cytokine production, bacterial load in peritoneal fluid, blood and lung tissue, myeloperoxidase (MPO) activity in lung and liver and different immune cell populations in spleen were studied. We found that Gα(i) proteins are rapidly activated by LPS followed by rapid inactivation. These studies provide the first direct evidence that Gα(i) proteins are modulated by TLR signaling. In following studies, PTx augmented LPS-induced plasma TNFα, IL-6, whereas MP-7 suppressed LPS-induced TNFα and decreased LPS-induced mortality. In sepsis studies, the survival rate post-CLP was significantly decreased in the Gα(i2) (-/-) mice compared to WT mice. CLP-induced plasma TNFα, IL-6, bacterial load in peritoneal fluid, blood and lung tissue and lung and liver MPO activity were significantly increased in Gα(i2) (-/-) compared to WT mice. Gα(i2) (-/-) mice also exhibited increased Th1 and Th2 responses compared to WT mice. Taken together, Gα(i) proteins are activated by LPS and negatively regulate endotoxemia and sepsis. Understanding the role of Gα(i2) protein in regulation of the inflammatory response in sepsis may provide novel targets for treatment of sepsis.
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Affiliation(s)
- Hongkuan Fan
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA.
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Cui Y, Liu H, Zhou M, Duan Y, Li N, Gong X, Hu R, Hong M, Hong F. Signaling pathway of inflammatory responses in the mouse liver caused by TiO2 nanoparticles. J Biomed Mater Res A 2010; 96:221-9. [PMID: 21105171 DOI: 10.1002/jbm.a.32976] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Accepted: 08/09/2010] [Indexed: 12/12/2022]
Abstract
In an effort to examine signaling pathway of inflammation of the mouse liver caused by intragastric administration of titanium dioxide nanoparticles (NPs), we assessed Toll-like receptor-2 (TLR2), TLR-4, IκB kinase (IKK-α, IKK-β), IκB nucleic factor-κB (NF-κB), NF-κBP52, NF-κBP65, tumor necrosis factor-α (TNF-α), NF-κB-inducible kinase (NIK), interleukin-2 (IL-2), biochemical parameters of liver functions, and histopathological changes and liver ultrastructure in the TiO(2) NPs-treated mice. The results showed the titanium accumulation in liver, histopathological changes and hepatocytes apoptosis of mice liver, and the liver function damaged by TiO(2) NPs. The real-time quantitative reverse transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay analyses showed that TiO(2) NPs can significantly increase the mRNA and protein expression of TLR2 and TLR4 and several inflammatory cytokines, including IKK1, IKK2, NF-κB, NF-κBP52, NF-κBP65, TNF-α, and NIK, and TiO(2) NPs can significantly decrease the mRNA and protein expression of IκB and IL-2. The results of this study added to our understanding of TiO(2) NPs-induced liver toxicity. It implied that the signaling pathway of liver injury in the TiO(2) NPs-stimulated mouse liver sequentially might occur via activation of TLRs→NIK→IκB kinase→NF-κB→TNF-α→inflammation→apoptosis→liver injury.
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Affiliation(s)
- Yaling Cui
- Medical College, Soochow University, Suzhou, People's Republic of China
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33
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Toll-like receptor 2-mediated sequential activation of MyD88 and MAPKs contributes to lipopolysaccharide-induced sp-a gene expression in human alveolar epithelial cells. Immunobiology 2010; 216:707-14. [PMID: 21112663 DOI: 10.1016/j.imbio.2010.10.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 10/26/2010] [Accepted: 10/26/2010] [Indexed: 01/13/2023]
Abstract
Surfactant proteins (SPs) produced by pulmonary epithelial cells participate in the regulation of sepsis-induced acute lung injury. Our previous study has shown that lipopolysaccharide (LPS), a Gram-negative bacterial outer membrane component, can regulate sp-a gene expression in human lung carcinoma type II epithelial A549 cells. This study was further designed to evaluate the signal-transducing mechanisms of LPS-induced sp-a gene expression. Exposure of A549 cells to LPS induced SP-A mRNA and protein production in time-dependent manners. Application of toll-like receptor 2 (TLR2) siRNA into A549 cells decreased the levels of this receptor and simultaneously inhibited LPS-induced SP-A mRNA expression. Sequentially, LPS enhanced phosphorylation of mitogen-activated protein kinase (MEK) 4 and c-Jun NH(2) terminal kinase 1 (JNK1) in time-dependent manners. Application of TLR2 siRNA decreased LPS-enhanced phosphorylation of MEK4 and JNK1. After knocking-down the translation of MyD88 by RNA interference, the LPS-triggered MEK4 phosphorylation was attenuated. Consequently, LPS augmented the translocation of c-Jun from the cytoplasm to nuclei without affecting c-Fos. Pretreatment of A549 cells with SP600125, an inhibitor of JNK1, significantly lowered LPS-induced SP-A mRNA production. Analyses of an electrophoretic mobility shift assay and a reporter gene further showed that LPS increased the transactivation activity of AP-1 in A549 cells. Therefore, the present study demonstrates that LPS can induce sp-a gene expression in human type II epithelial A549 cells through TLR2-mediated sequential activation of MyD88-MEK4-JNK1-AP-1.
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Chang HC, Lin KH, Tai YT, Chen JT, Chen RM. Lipoteichoic acid-induced TNF-α and IL-6 gene expressions and oxidative stress production in macrophages are suppressed by ketamine through downregulating Toll-like receptor 2-mediated activation oF ERK1/2 and NFκB. Shock 2010; 33:485-92. [PMID: 19823118 DOI: 10.1097/shk.0b013e3181c3cea5] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Lipoteichoic acid (LTA), a gram-positive bacterial outer membrane component, can cause septic shock. Our previous studies showed that ketamine has anti-inflammatory and antioxidant effects on gram-negative LPS-induced macrophage activation. In this study, we further evaluated the effects of ketamine on the regulation of LTA-induced TNF-alpha and IL-6 gene expressions and oxidative stress production in macrophages and its possible mechanisms. Exposure of macrophages to a therapeutic concentration of ketamine (100 microM) inhibited LTA-induced TNF-alpha and IL-6 expressions at protein or mRNA levels. In parallel, ketamine at 100 microM reduced LTA-stimulated phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). Sequentially, ketamine reduced the LTA-triggered translocation of nuclear factor-kappaB (NFkappaB) from the cytoplasm to nuclei and its transactivation activity. Pretreatment with PD98059, an inhibitor of ERK, decreased LTA-enhanced NFkappaB activation and TNF-alpha and IL-6 mRNA syntheses. Cotreatment with ketamine and PD98059 synergistically suppressed the LTA-induced translocation and transactivation of NFkappaB and biosyntheses of TNF-alpha and IL-6 mRNA. Application of Toll-like receptor 2 (TLR2) small interfering RNA (si)RNA into macrophages decreased the levels of this receptor, and simultaneously ameliorated LTA-augmented NFkappaB transactivation and consequent production of TNF-alpha and IL-6 mRNA. Cotreatment with ketamine and TLR2 siRNA synergistically lowered TNF-alpha and IL-6 mRNA syntheses in LTA-activated macrophages. Ketamine and TLR2 siRNA could reduce the LTA-induced increases in production of nitrite and intracellular reactive oxygen species in macrophages, and their combination had better effects than a single exposure. Thus, this study shows that one possible mechanism involved in ketamine-induced inhibition of LTA-induced TNF-alpha and IL-6 gene expressions and oxidative stress production is through downregulating TLR2-mediated phosphorylation of ERK1/2 and the subsequent translocation and transactivation of NFkappaB.
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Affiliation(s)
- Huai-Chia Chang
- Graduate Institute of Medical Sciences, Taipei Medical University, 250 Wu-Xing Street, Taipei, Taiwan
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35
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Carbonetti NH. Pertussis toxin and adenylate cyclase toxin: key virulence factors of Bordetella pertussis and cell biology tools. Future Microbiol 2010; 5:455-69. [PMID: 20210554 DOI: 10.2217/fmb.09.133] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pertussis toxin and adenylate cyclase toxin are two important virulence factors of Bordetella pertussis, the bacterial cause of the respiratory disease pertussis or whooping cough. In addition to studies on the structure, function and role in pathogenesis of these two toxins, they are both used as cell biology tools for a variety of applications owing to their ability to enter mammalian cells, perform enzymatic activities and modify cell signaling events. In this article, recent data from the research literature that enhance our understanding of the nature of these two toxins, their role in the pathogenesis of B. pertussis infection and disease, particularly in modulating host immune responses, and their use as tools for other areas of research will be outlined.
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Affiliation(s)
- Nicholas H Carbonetti
- Department of Microbiology & Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Functional significance of the Toll-like receptor 4 promoter gene polymorphisms in the Chinese Han population. Crit Care Med 2010; 38:1292-9. [DOI: 10.1097/ccm.0b013e3181d8ad12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Marty C, Ye RD. Heterotrimeric G protein signaling outside the realm of seven transmembrane domain receptors. Mol Pharmacol 2010; 78:12-8. [PMID: 20404072 DOI: 10.1124/mol.110.063453] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Heterotrimeric G proteins, consisting of the guanine nucleotide-binding Galpha subunits with GTPase activity and the closely associated Gbeta and Ggamma subunits, are important signaling components for receptors with seven transmembrane domains (7TMRs). These receptors, also termed G protein-coupled receptors (GPCRs), act as guanine nucleotide exchange factors upon agonist stimulation. There is now accumulating evidence for noncanonical functions of heterotrimeric G proteins independent of 7TMR coupling. Galpha proteins belonging to all 4 subfamilies, including G(s), G(i), G(q), and G(12) are found to play important roles in receptor tyrosine kinase signaling, regulation of oxidant production, development, and cell migration, through physical and functional interaction with proteins other than 7TMRs. Association of Galpha with non-7TMR proteins also facilitates presentation of these G proteins to specific cellular microdomains. This Minireview aims to summarize our current understanding of the noncanonical roles of Galpha proteins in cell signaling and to discuss unresolved issues including regulation of Galpha activation by proteins other than the 7TMRs.
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Affiliation(s)
- Caroline Marty
- Institut National de la Santé et de la Recherche Médicale, Université Paris XI, Institut Gustave Roussy, Villejuif, France
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Molecular mechanisms of propofol-involved suppression of no biosynthesis and inducible iNOS gene expression in LPS-stimulated macrophage-like raw 264.7 cells. Shock 2010; 33:93-100. [PMID: 19333139 DOI: 10.1097/shk.0b013e3181a6eaf5] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Wu TT, Chen TL, Chen RM. Lipopolysaccharide triggers macrophage activation of inflammatory cytokine expression, chemotaxis, phagocytosis, and oxidative ability via a toll-like receptor 4-dependent pathway: validated by RNA interference. Toxicol Lett 2009; 191:195-202. [PMID: 19735705 DOI: 10.1016/j.toxlet.2009.08.025] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 08/29/2009] [Accepted: 08/31/2009] [Indexed: 11/28/2022]
Abstract
RNA interference has been extensively used to knock-down the translation of certain genes. Toll-like receptor 4 (TLR4) produced by macrophages can be activated in response to endotoxin stimulation. This study used the RNA interference technique to evaluate the roles of TLR4 in lipopolysaccharide (LPS)-stimulated activation of macrophages from the aspects of cytokine production, chemotaxis, phagocytosis, and oxidative ability. Exposure of macrophages to 1, 25, 50, 100 ng/mL LPS for 1, 6, and 24 h did not affect cell viability. Meanwhile, treatment with 100 ng/mL LPS induced interleukin (IL)-1beta protein and mRNA syntheses in a time-dependent manner. Application of TLR4 small interference (si)RNA into macrophages decreased the levels of this receptor, and simultaneously ameliorated LPS-induced IL-1beta and IL-6 mRNA production. Transwell analysis showed that LPS increased chemotactic activity of macrophages, but application of TLR4 siRNA reduced such an effect. Phagocytic activities of macrophages were significantly augmented following LPS treatment. However, knocking-down the translation of TLR4 mRNA using RNA interference lowered the LPS-enhanced phagocytic activity. Analysis of flow cytometry revealed that LPS increased oxidative ability of macrophages, but TLR4 siRNA inhibited such development. This study used RNA interference techniques to show that TLR4 can mediate LPS-induced macrophage activations of IL-1beta and IL-6 gene expression, chemotaxis, phagocytosis, and oxidative ability.
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Affiliation(s)
- Tsu-Tuan Wu
- Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan
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Abstract
Ischemia-reperfusion (I/R) injuries are implicated in a large array of pathological conditions such as myocardial infarction, cerebral stroke, and hepatic, renal, and intestinal ischemia, as well as following cardiovascular and transplant surgeries. The hallmark of these pathologies is excessive inflammation. Toll-like receptors (TLRs) are recognized as one of the main contributors to pathogen-induced inflammation and, more recently, injury-induced inflammation. Endogenous ligands such as low-molecular hyaluronic acid, fibronectin, heat shock protein 70, and heparin sulfate were all found to be cleaved in the inflamed tissue and to activate TLR2 and TLR4, initiating an inflammatory response even in the absence of pathogens and infiltrating immune cells. In this review, we discuss the contribution of TLR activation in hepatic, renal, cerebral, intestinal, and myocardial I/R injuries. A greater understanding of the role of TLRs in I/R injuries may aid in the development of specific TLR-targeted therapeutics to treat these conditions.
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Wu GJ, Chen TL, Chang CC, Chen RM. Propofol suppresses tumor necrosis factor-alpha biosynthesis in lipopolysaccharide-stimulated macrophages possibly through downregulation of nuclear factor-kappa B-mediated toll-like receptor 4 gene expression. Chem Biol Interact 2009; 180:465-71. [PMID: 19433076 DOI: 10.1016/j.cbi.2009.05.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 04/02/2009] [Accepted: 05/04/2009] [Indexed: 10/20/2022]
Abstract
Lipopolysaccharide (LPS), a gram-negative bacterial outer membrane component, can activate macrophages via a toll-like receptor 4-dependent pathway. Our previous study has shown that propofol, an intravenous anesthetic reagent, has anti-inflammatory effects. This study was further aimed to evaluate the roles of toll-like receptor 4 in propofol-caused suppression of tumor necrosis factor-alpha (TNF-alpha) biosynthesis in LPS-stimulated macrophages and its possible molecular mechanisms. Exposure of macrophages to propofol and LPS did not affect cell viability. Meanwhile, the LPS-caused augmentations in the productions of TNF-alpha protein and mRNA were significantly decreased following incubation with a therapeutic concentration of propofol (50 microM). Analysis of toll-like receptor 4 small interference (si)RNA revealed that this membrane receptor might participate in the propofol-caused suppression of TNF-alpha biosynthesis. Treatment of macrophages with LPS-induced toll-like receptor 4 protein and mRNA productions. Propofol at a clinically relevant concentration could inhibit such induction. In parallel, the LPS-induced translocation and transactivation of transcription factor nuclear factor-kappa B (NFkappaB) were significantly alleviated following propofol incubation. There are several NFkappaB DNA-binding motifs found in the promoter region of toll-like receptor 4. Therefore, this study shows that propofol at a therapeutic concentration can downregulate TNF-alpha biosynthesis possibly via inhibition of NFkappaB-mediated toll-like receptor 4 gene expression.
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Affiliation(s)
- Gong-Jhe Wu
- Department of Anesthesiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
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Riekenberg S, Farhat K, Debarry J, Heine H, Jung G, Wiesmüller KH, Ulmer AJ. Regulators of G-protein signalling are modulated by bacterial lipopeptides and lipopolysaccharide. FEBS J 2008; 276:649-59. [PMID: 19120454 DOI: 10.1111/j.1742-4658.2008.06813.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Regulators of G-protein signalling accelerate the GTPase activity of G(alpha) subunits, driving G proteins in their inactive GDP-bound form. This property defines them as GTPase activating proteins. Here the effect of different Toll-like receptor agonists on RGS1 and RGS2 expression in murine bone marrow-derived macrophages and J774 cells was analysed. After stimulation with TLR2/1 or TLR2/6 lipopeptide ligands and the TLR4/MD2 ligand lipopolysaccharide, microarray analyses show only modulation of RGS1 and RGS2 among all the regulators of G-protein signalling tested. Real-time PCR confirmed modulation of RGS1 and RGS2. In contrast to RGS2, which was always downregulated, RGS1 mRNA was upregulated during the first 30 min after stimulation, followed by downregulation. Similar results were also found in the murine macrophage cell line J774. The ligand for intracellular TLR9 modulates RGS1 and RGS2 in a similar manner. However, the TLR3 ligand poly(I:C) permanently upregulates RGS1 and RGS2 expression indicating a different modulation by the MyD88- and TRIF-signalling pathway. This was confirmed using MyD88(-/-) and TRIF(-/-) bone marrow-derived macrophages. Modulation of RGS1 and RGS2 by Toll-like receptor ligands plays an important role during inflammatory and immunological reactions after bacterial and viral infection.
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Affiliation(s)
- Sabine Riekenberg
- Cellular Immunology, Department of Immunology and Cell Biology, Research Center Borstel, Germany
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Fan H, Zingarelli B, Harris V, Tempel GE, Halushka PV, Cook JA. Lysophosphatidic acid inhibits bacterial endotoxin-induced pro-inflammatory response: potential anti-inflammatory signaling pathways. Mol Med 2008; 14:422-8. [PMID: 18431464 DOI: 10.2119/2007-00106.fan] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Accepted: 04/14/2008] [Indexed: 11/06/2022] Open
Abstract
Previous studies have demonstrated that heterotrimeric guanine nucleotide-binding regulatory (Gi) protein-deficient mice exhibit augmented inflammatory responses to lipopolysaccharide (LPS). These findings suggest that Gi protein agonists will suppress LPS-induced inflammatory gene expression. Lysophosphatidic acid (LPA) activates G protein-coupled receptors leading to Gi protein activation. We hypothesized that LPA will inhibit LPS-induced inflammatory responses through activation of Gi-coupled anti-inflammatory signaling pathways. We examined the anti-inflammatory effect of LPA on LPS responses both in vivo and in vitro in CD-1 mice. The mice were injected intravenously with LPA (10 mg/kg) followed by intraperitoneal injection of LPS (75 mg/kg for survival and 25 mg/kg for other studies). LPA significantly increased the mice survival to endotoxemia (P < 0.05). LPA injection reduced LPS-induced plasma TNF-alpha production (69 +/- 6%, P < 0.05) and myeloperoxidase (MPO) activity in lung (33 +/- 9%, P < 0.05) as compared to vehicle injection. LPS-induced plasma IL-6 was unchanged by LPA. In vitro studies with peritoneal macrophages paralleled results from in vivo studies. LPA (1 and 10 microM) significantly inhibited LPS-induced TNFalpha production (61 +/- 9% and 72 +/- 9%, respectively, P < 0.05) but not IL-6. We further demonstrated that the anti-inflammatory effect of LPA was reversed by ERK 1/2 and phosphatase inhibitors, suggesting that ERK 1/2 pathway and serine/threonine phosphatases are involved. Inhibition of phosphatidylinositol 3 (PI3) kinase signaling pathways also partially reversed the LPA anti-inflammatory response. However, LPA did not alter NFkappaB and peroxisome proliferator-activated receptor gamma (PPARgamma) activation. Inhibitors of PPARgamma did not alter LPA-induced inhibition of LPS signaling. These studies demonstrate that LPA has significant anti-inflammatory activities involving activation of ERK 1/2, serine/threonine phosphatases, and PI3 kinase signaling pathways.
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Affiliation(s)
- Hongkuan Fan
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, USA
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Bischoff DS, Zhu JH, Makhijani NS, Yamaguchi DT. Acidic pH stimulates the production of the angiogenic CXC chemokine, CXCL8 (interleukin-8), in human adult mesenchymal stem cells via the extracellular signal-regulated kinase, p38 mitogen-activated protein kinase, and NF-kappaB pathways. J Cell Biochem 2008; 104:1378-92. [PMID: 18275043 DOI: 10.1002/jcb.21714] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Blood vessel injury results in limited oxygen tension and diffusion leading to hypoxia, increased anaerobic metabolism, and elevated production of acidic metabolites that cannot be easily removed due to the reduced blood flow. Therefore, an acidic extracellular pH occurs in the local microenvironment of disrupted bone. The potential role of acidic pH and glu-leu-arg (ELR(+)) CXC chemokines in early events in bone repair was studied in human mesenchymal stem cells (hMSCs) treated with medium of decreasing pH (7.4, 7.0, 6.7, and 6.4). The cells showed a reciprocal increase in CXCL8 (interleukin-8, IL-8) mRNA levels as extracellular pH decreased. At pH 6.4, CXCL8 mRNA was induced >60x in comparison to levels at pH 7.4. hMSCs treated with osteogenic medium (OGM) also showed an increase in CXCL8 mRNA with decreasing pH; although, at a lower level than that seen in cells grown in non-OGM. CXCL8 protein was secreted into the medium at all pHs with maximal induction at pH 6.7. Inhibition of the G-protein-coupled receptor alpha, G(alphai), suppressed CXCL8 levels in response to acidic pH; whereas phospholipase C inhibition had no effect on CXCL8. The use of specific mitogen-activated protein kinase (MAPK) signal transduction inhibitors indicated that the pH-dependent increase in CXCL8 mRNA is due to activation of ERK and p38 pathways. The JNK pathway was not involved. NF-kappaB inhibition resulted in a decrease in CXCL8 levels in hMSCs grown in non-OGM. However, OGM-differentiated hMSCs showed an increase in CXCL8 levels when treated with the NF-kappaB inhibitor PDTC, a pyrrolidine derivative of dithiocarbamate.
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Affiliation(s)
- David S Bischoff
- Research Service, VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
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Bischoff DS, Zhu JH, Makhijani NS, Kumar A, Yamaguchi DT. Angiogenic CXC chemokine expression during differentiation of human mesenchymal stem cells towards the osteoblastic lineage. J Cell Biochem 2008; 103:812-24. [PMID: 17583554 DOI: 10.1002/jcb.21450] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The potential role of ELR(+) CXC chemokines in early events in bone repair was studied using human mesenchymal stem cells (hMSCs). Inflammation, which occurs in the initial phase of tissue healing in general, is critical to bone repair. Release of cytokines from infiltrating immune cells and injured bone can lead to recruitment of MSCs to the region of repair. CXC chemokines bearing the Glu-Leu-Arg (ELR) motif are also released by inflammatory cells and serve as angiogenic factors stimulating chemotaxis and proliferation of endothelial cells. hMSCs, induced to differentiate with osteogenic medium (OGM) containing ascorbate, beta-glycerophosphate (beta-GP), and dexamethasone (DEX), showed an increase in mRNA and protein secretion of the ELR(+) CXC chemokines CXCL8 and CXCL1. CXCL8 mRNA half-life studies reveal an increase in mRNA stability upon OGM stimulation. Increased expression and secretion is a result of DEX in OGM and is dose-dependent. Inhibition of the glucocorticoid receptor with mifepristone only partially inhibits DEX-stimulated CXCL8 expression indicating both glucocorticoid receptor dependent and independent pathways. Treatment with signal transduction inhibitors demonstrate that this expression is due to activation of the ERK and p38 mitogen-activated protein kinase (MAPK) pathways and is mediated through the G(alphai)-coupled receptors. Angiogenesis assays demonstrate that OGM-stimulated conditioned media containing secreted CXCL8 and CXCL1 can induce angiogenesis of human microvascular endothelial cells in an in vitro Matrigel assay.
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Affiliation(s)
- D S Bischoff
- Research Service, Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, California 90073, USA
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Singer P, Shapiro H, Theilla M, Anbar R, Singer J, Cohen J. Anti-inflammatory properties of omega-3 fatty acids in critical illness: novel mechanisms and an integrative perspective. Intensive Care Med 2008; 34:1580-92. [PMID: 18461305 DOI: 10.1007/s00134-008-1142-4] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Accepted: 04/19/2008] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Fish oil-based nutrition is protective in severe critical care conditions. Regulation of the activity of transcription factor NF-kappaB is an important therapeutic effect of the major omega-3 fatty acids in fish oil, eicosapentaenoic and docosahexaenoic acid (EPA and DHA). METHODS AND RESULTS Using the articles obtained by a Pubmed research, this article reviews three aspects of NF-kappaB/inflammatory inhibition by fish oil. (1) Inhibition of the NF-kappaB pathway at several subsequent steps: extracellular, free omega-3 inhibits the activation of the Toll-like receptor 4 by endotoxin and free saturated fatty acids. In addition, EPA/DHA blocks the signaling cascade between Toll-like/cytokine receptors and the activator of NF-kappaB, IKK. Oxidized omega-3 also interferes with the initiation of transcription by NF-kappaB. (2) The altered profile of lipid mediators generated during inflammation, with production of the newly identified, DHA-derived inflammation-resolving mediator classes (in addition to the formation of less pro-inflammatory eicosanoids from EPA). Resolvin D1 and Protectin D1 are potent, endogenous, DHA-derived lipid mediators that attenuate neutrophil migration and tissue injury in peritonitis and ischemia-reperfusion injury. Their production is increased in the later stages of an inflammatory response, at which time they enhance the removal of neutrophils. (3) Modulation of vagal tone with potential anti-inflammatory effects: vagal fibers innervating the viscera down-regulate inflammation by activating nicotinic receptors upon infiltrating and resident macrophages. Stimulation of the efferent vagus is therapeutic in experimental septic shock. Fish oil supplementation increases vagal tone following myocardial infarction and in experimental human endotoxinemia. CONCLUSION It remains to be shown whether these pleiotropic actions of EPA/DHA contribute to fish oil's therapeutic effect in sepsis.
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Affiliation(s)
- Pierre Singer
- Department of General Intensive Care, Institute for Nutrition Research, Petach Tikva, Israel.
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Wu GJ, Chen TL, Ueng YF, Chen RM. Ketamine inhibits tumor necrosis factor-α and interleukin-6 gene expressions in lipopolysaccharide-stimulated macrophages through suppression of toll-like receptor 4-mediated c-Jun N-terminal kinase phosphorylation and activator protein-1 activation. Toxicol Appl Pharmacol 2008; 228:105-13. [DOI: 10.1016/j.taap.2007.11.027] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Revised: 11/16/2007] [Accepted: 11/28/2007] [Indexed: 11/27/2022]
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Magocsi M, Vizi ES, Selmeczy Z, Brózik A, Szelenyi J. Multiple G-protein-coupling specificity of beta-adrenoceptor in macrophages. Immunology 2007; 122:503-13. [PMID: 17949419 DOI: 10.1111/j.1365-2567.2007.02658.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Adrenergic signalling of the immune system is one of the important modulator pathways of the inflammatory immune response realized via G protein-mediated pathways. The resulted signal depends on the type of the receptor-coupled G-protein (GPCR) that, according to the classical paradigm in the case of beta-adrenergic receptor (beta-AR), is Gs-type. Recently, alternate and/or multiple G protein coupling specificity of GPCRs have been demonstrated including a switch from Gs to Gi binding. The possibility of a Gs/Gi switch and its role in the immune response of macrophages has not been investigated yet. In this study, we demonstrate that beta-adrenergic stimulation itself is able to induce a transient mitogen-activated protein kinase phosphorylation in murine peritoneal macrophages in a pertussis toxin-sensitive manner, suggesting that the Gs/Gi switch also occurs in the immune system. Although this process is very rapid, it can influence different signalling pathways and can reprogramme effector functions suggesting that sympathetic modulation of the defence mechanism of the innate immune system has an additional, Gs/Gi switch-dependent component.
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Affiliation(s)
- Maria Magocsi
- Institute of Haematology and Immunology, National Medical Centre, Budapest, Hungary.
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Duan ZX, Zhu PF, Dong H, Gu W, Yang C, Liu Q, Wang ZG, Jiang JX. Functional significance of the TLR4/11367 polymorphism identified in Chinese Han population. Shock 2007; 28:160-4. [PMID: 17529905 DOI: 10.1097/shk.0b013e31803df782] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Toll-like receptor 4 (TLR4) is the central signaling receptor for lipopolysaccharide (LPS) in mammals. This study was designed to investigate the functional significance of the G11367C polymorphism, which is a novel variant we identified in the 3' untranslated region of TLR4 gene in Chinese Han population. Three hundred seventy healthy volunteers were selected. The TLR4/11367 polymorphism was genotyped using single-tube bidirectional allele-specific amplification method. The TLR4 protein expression on peripheral leukocytes and plasma tumor necrosis factor alpha levels were determined by means of flow cytometry and enzyme-linked immunosorbent assay. The post-transcriptional effect of the 11367 polymorphism was evaluated by means of reporter gene assay and real-time quantitative polymerase chain reaction. The G11367C polymorphism is a common allele in Chinese Han population, with minor allele frequency of 14.7%. In response to ex vivo LPS stimulation, the TLR4 expression on the surface of peripheral leukocytes and the plasma tumor necrosis factor alpha levels were significantly lower in carriers of 11367C variant allele than in carriers of 11367G allele. This association was allele dose dependent. We also found that the activity and the mRNA expression of luciferase was significantly smaller in human embryonic kidney 293 cells transfected with construct containing 11367C allele than in those transfected with construct containing 11367G allele. Together, these results suggest that the TLR4/11367 polymorphism may be a functional single nucleotide polymorphism, which could attenuate the LPS-induced transmembrane signaling through the alteration of post-transcriptional regulation of 3' untranslated region and target gene expression.
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Affiliation(s)
- Zhao-xia Duan
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Daping, Chongqing 400-042, China
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Chen J, Rao JN, Zou T, Liu L, Marasa BS, Xiao L, Zeng X, Turner DJ, Wang JY. Polyamines are required for expression of Toll-like receptor 2 modulating intestinal epithelial barrier integrity. Am J Physiol Gastrointest Liver Physiol 2007; 293:G568-76. [PMID: 17600044 DOI: 10.1152/ajpgi.00201.2007] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The Toll-like receptors (TLRs) allow mammalian intestinal epithelium to detect various microbes and activate innate immunity after infection. TLR2 and TLR4 have been identified in intestinal epithelial cells (IECs) as fundamental components of the innate immune response to bacterial pathogens, but the exact mechanism involved in control of TLR expression remains unclear. Polyamines are implicated in a wide variety of biological functions, and regulation of cellular polyamines is a central convergence point for the multiple signaling pathways driving different epithelial cell functions. The current study determined whether polyamines regulate TLR expression, thereby modulating intestinal epithelial barrier function. Depletion of cellular polyamines by inhibiting ornithine decarboxylase (ODC) with alpha-difluoromethylornithine decreased levels of TLR2 mRNA and protein, whereas increased polyamines by ectopic overexpression of the ODC gene enhanced TLR2 expression. Neither intervention changed basal levels of TLR4. Exposure of normal IECs to low-dose (5 microg/ml) LPS increased ODC enzyme activity and stimulated expression of TLR2 but not TLR4, while polyamine depletion prevented this LPS-induced TLR2 expression. Decreased TLR2 in polyamine-deficient cells was associated with epithelial barrier dysfunction. In contrast, increased TLR2 by the low dose of LPS enhanced epithelial barrier function, which was abolished by inhibition of TLR2 expression with specific, small interfering RNA. These results indicate that polyamines are necessary for TLR2 expression and that polyamine-induced TLR2 activation plays an important role in regulating epithelial barrier function.
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Affiliation(s)
- Jie Chen
- Department of Surgery, Baltimore Veterans Affairs Medical Center, 10 North Greene Street, Baltimore, MD 21201, USA.
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