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Identification of G protein subunit alpha i2 as a promising therapeutic target of hepatocellular carcinoma. Cell Death Dis 2023; 14:143. [PMID: 36805440 PMCID: PMC9941495 DOI: 10.1038/s41419-023-05675-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 02/22/2023]
Abstract
Hepatocellular carcinoma (HCC) is a global health problem. Its incidence and mortality are increasing. Exploring novel therapeutic targets against HCC is important and urgent. We here explored the expression and potential function of Gαi2 (G protein subunit alpha i2) in HCC. The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) database shows that the number of Gαi2 transcripts in HCC tissues is significantly higher than that in the normal liver tissues. Moreover, Gαi2 overexpression in HCC correlates with poor prognosis of the patients. Gαi2 mRNA and protein expression are also elevated in local HCC tissues and different human HCC cells. In patient-derived primary HCC cells and immortalized HepG2 cells, Gαi2 silencing (by targeted shRNA) or knockout (KO, by the dCas9-sgRNA method) largely suppressed cell proliferation and motility, while inducing cell cycle arrest and caspase-apoptosis activation. Moreover, Gαi2 silencing or KO-induced reactive oxygen species (ROS) production and oxidative injury in primary and HepG2 HCC cells. Whereas different antioxidants ameliorated Gαi2-shRNA-induced anti-HCC cell activity. Using a lentiviral construct, Gαi2 overexpression further augmented proliferation and motility of primary and immortalized HCC cells. Further studies revealed that the binding between the transcription factor early growth response zinc finger transcription factor 1 (EGR1) and Gαi2 DNA promoter was significantly increased in HCC tissues and cells. In vivo, intratumoral injection of Gαi2 shRNA adeno-associated virus significantly hindered HCC xenograft growth in nude mice. Moreover, the growth of Gαi2-KO HCC xenografts in the nude mice was remarkably slow. Gαi2 depletion, oxidative injury, and apoptosis induction were detected in Gαi2-silenced or Gαi2-KO HCC xenografts. Together, overexpressed Gαi2 is required for HCC cell growth in vitro and in vivo, representing as a novel and promising diagnosis marker and therapeutic target of HCC.
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2
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Wang Y, Liu F, Wu J, Zhang MQ, Chai JL, Cao C. G protein inhibitory α subunit 2 is a molecular oncotarget of human glioma. Int J Biol Sci 2023; 19:865-879. [PMID: 36778118 PMCID: PMC9909998 DOI: 10.7150/ijbs.79355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/27/2022] [Indexed: 01/11/2023] Open
Abstract
Identification of novel therapeutic oncotargets for human glioma is extremely important. Here we tested expression, potential functions and underlying mechanisms of G protein inhibitory α subunit 2 (Gαi2) in glioma. Bioinformatics analyses revealed that Gαi2 expression is significantly elevated in human glioma, correlating with poor patients' survival, higher tumor grade and wild-type IDH status. Moreover, increased Gαi2 expression was also in local glioma tissues and different glioma cells. In primary and immortalized (A172) glioma cells, Gαi2 shRNA or knockout (KO, by Cas9-sgRNA) potently suppressed viability, proliferation, and mobility, and induced apoptosis. Ectopic Gαi2 overexpression, using a lentiviral construct, further augmented malignant behaviors in glioma cells. p65 phosphorylation, NFκB activity and expression of NFκB pathway genes were decreased in Gαi2-depleted primary glioma cells, but increased following Gαi2 overexpression. There was an increased binding between Gαi2 promoter and Sp1 (specificity protein 1) transcription factor in glioma tissues and different glioma cells. In primary glioma cells Gαi2 expression was significantly reduced following Sp1 silencing, KO or inhibition. In vivo studies revealed that Gαi2 shRNA-expressing AAV intratumoral injection hindered growth of subcutaneous glioma xenografts in nude mice. Moreover, Gαi2 KO inhibited intracranial glioma xenograft in nude mice. Gαi2 depletion, NFκB inhibition and apoptosis induction were observed in subcutaneous and intracranial glioma xenografts with Gαi2 depletion. Together, overexpressed Gαi2 is important for glioma cell growth possibly by promoting NFκB cascade activation.
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Affiliation(s)
- Yin Wang
- Institute of Neuroscience, Soochow University, Institute for Excellence in Clinical Medicine of Kunshan First People's Hospital and Soochow University, Suzhou, China.,Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Fang Liu
- Department of Neurosurgery, The affiliated Changzhou No.2 People's Hospital of Nanjing Medical University, Changzhou, China
| | - Jiang Wu
- Department of Neurosurgery, the First Affiliated Hospital of Soochow University, Suzhou, China
| | - Mei-Qing Zhang
- Institute of Neuroscience, Soochow University, Institute for Excellence in Clinical Medicine of Kunshan First People's Hospital and Soochow University, Suzhou, China.,Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Jin-Long Chai
- Institute of Neuroscience, Soochow University, Institute for Excellence in Clinical Medicine of Kunshan First People's Hospital and Soochow University, Suzhou, China.,Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Cong Cao
- Institute of Neuroscience, Soochow University, Institute for Excellence in Clinical Medicine of Kunshan First People's Hospital and Soochow University, Suzhou, China.,Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China.,The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China
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3
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Zhang J, Yin DP, Zhang Y, Zhang JN, Yang Y, Zhang ZQ, Zhou L, Lv Y, Huang HW, Cao C. Identification of Gαi3 as a novel molecular therapeutic target of cervical cancer. Int J Biol Sci 2022; 18:5667-5680. [PMID: 36263185 PMCID: PMC9576524 DOI: 10.7150/ijbs.77126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Accepted: 08/25/2022] [Indexed: 01/12/2023] Open
Abstract
Here we studied expression and potential functions of Gαi3 in cervical cancer. The bioinformatics analysis together with the results from local patients' tissues revealed that Gαi3 expression was remarkably elevated in human cervical cancer tissues and different cervical cancer cells, and was associated with poor overall survival and poor disease-specific survival of patients. Gαi3 depletion resulted in profound anti-cervical cancer activity. In primary or immortalized cervical cancer cells, Gαi3 shRNA or CRISPR/Cas9-caused Gαi3 knockout/KO largely hindered cell proliferation and migration, and provoked apoptosis. On the contrast, ectopic Gαi3 overexpression further enhanced cervical cancer proliferation and migration. Akt-mTOR activation in primary cervical cancer cells was significantly reduced after Gαi3 silencing or KO, but was augmented following Gαi3 overexpression. Further studies revealed that the transcription factor GATA4 binding to Gαi3 promoter region was significantly enhanced in cervical cancer tissues and cells. Gαi3 expression was decreased by GATA4 shRNA, but upregulated following GATA4 overexpression. In vivo, the growth of cervical cancer xenografts was robustly suppressed after Gαi3 silencing or KO. Gαi3 depletion and Akt-mTOR inactivation were detected in Gαi3-silenced/-KO cervical cancer xenograft tissues. Together, upregulated Gαi3 is a valuable oncotarget of cervical cancer.
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Affiliation(s)
- Jie Zhang
- Obstetrics and Gynecology Department, The Affiliated Zhangjiagang Hospital of Soochow University, Institute of Neuroscience, Soochow University, Suzhou, China
| | - De-pei Yin
- Department of Otorhinolaryngology Head and Neck Surgery, Children's Hospital of Soochow University, Suzhou, China
| | - Yan Zhang
- Department of Radiotherapy and Oncology, Affiliated Kunshan Hospital of Jiangsu University, Suzhou, China
| | - Jia-nan Zhang
- Obstetrics and Gynecology Department, The Affiliated Zhangjiagang Hospital of Soochow University, Institute of Neuroscience, Soochow University, Suzhou, China
| | - Yan Yang
- Obstetrics and Gynecology Department, The Affiliated Zhangjiagang Hospital of Soochow University, Institute of Neuroscience, Soochow University, Suzhou, China
| | - Zhi-qing Zhang
- Obstetrics and Gynecology Department, The Affiliated Zhangjiagang Hospital of Soochow University, Institute of Neuroscience, Soochow University, Suzhou, China
| | - Li Zhou
- Center of Translational Medicine, The Affiliated Zhangjiagang Hospital of Soochow University, Suzhou, China
| | - Yan Lv
- Center of Translational Medicine, The Affiliated Zhangjiagang Hospital of Soochow University, Suzhou, China.,✉ Corresponding authors: Dr. Yan Lv, E-mail: ; Prof. Hai-wei Huang, E-mail: ; Prof. Cong Cao, E-mail:
| | - Hai-wei Huang
- Obstetrics and Gynecology Department, The Affiliated Zhangjiagang Hospital of Soochow University, Institute of Neuroscience, Soochow University, Suzhou, China.,✉ Corresponding authors: Dr. Yan Lv, E-mail: ; Prof. Hai-wei Huang, E-mail: ; Prof. Cong Cao, E-mail:
| | - Cong Cao
- Obstetrics and Gynecology Department, The Affiliated Zhangjiagang Hospital of Soochow University, Institute of Neuroscience, Soochow University, Suzhou, China.,✉ Corresponding authors: Dr. Yan Lv, E-mail: ; Prof. Hai-wei Huang, E-mail: ; Prof. Cong Cao, E-mail:
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Wang Y, Liu YY, Chen MB, Cheng KW, Qi LN, Zhang ZQ, Peng Y, Li KR, Liu F, Chen G, Cao C. Neuronal-driven glioma growth requires Gαi1 and Gαi3. Theranostics 2021; 11:8535-8549. [PMID: 34373757 PMCID: PMC8343996 DOI: 10.7150/thno.61452] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 07/08/2021] [Indexed: 12/17/2022] Open
Abstract
Neuroligin-3 (NLGN3) is necessary and sufficient to promote glioma cell growth. The recruitment of Gαi1/3 to the ligand-activated receptor tyrosine kinases (RTKs) is essential for mediating oncogenic signaling. Methods: Various genetic strategies were utilized to examine the requirement of Gαi1/3 in NLGN3-driven glioma cell growth. Results: NLGN3-induced Akt-mTORC1 and Erk activation was inhibited by decreasing Gαi1/3 expression. In contrast ectopic Gαi1/3 overexpression enhanced NLGN3-induced signaling. In glioma cells, NLGN3-induced cell growth, proliferation and migration were attenuated by Gαi1/3 depletion with shRNA, but facilitated with Gαi1/3 overexpression. Significantly, Gαi1/3 silencing inhibited orthotopic growth of patient-derived glioma xenografts in mouse brain, whereas forced Gαi1/3-overexpression in primary glioma xenografts significantly enhanced growth. The growth of brain-metastatic human lung cancer cells in mouse brain was largely inhibited with Gαi1/3 silencing. It was however expedited with ectopic Gαi1/3 overexpression. In human glioma Gαi3 upregulation was detected, correlating with poor prognosis. Conclusion: Gαi1/3 mediation of NLGN3-induced signaling is essential for neuronal-driven glioma growth.
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DNMT1 mediated promoter methylation of GNAO1 in hepatoma carcinoma cells. Gene 2018; 665:67-73. [DOI: 10.1016/j.gene.2018.04.080] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 03/20/2018] [Accepted: 04/26/2018] [Indexed: 02/07/2023]
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Nasibyan LS, Philyppov IB. EFFECT OF PEPTIDOGLYCANE OF STAPHYLOCOCCUS AUREUS CELL WALL ON THE MECHANISM OF REGULATION OF CONTRACTILE ACTIVITY OF RAT MYOMETRIUM BY ADENYLATE CYCLASE SYSTEM. ACTA ACUST UNITED AC 2018. [PMID: 29537197 DOI: 10.15407/fz62.01.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The revue deals with the role of each component of adenylate cyclase regulatory system in the rat myometrial contractile activity modulation by the peptidoglycane of Staphylococcus aureus. Noradrenalin and salbutamol were used to investigate peptidoglycane impact on the myometrial β-adrenergic receptors. It was shown that inhibited by these substances myometrial contractility increased to the initial level after peptidoglycane application. The same effect we observed under the cAMP level elevation by forscolin. Peptidoglycan’ s ability to strengthen contractions was inhibited by the 8-brom-cAMP and papaverine application. Stimulation of Gs-protein by the cholera toxin didn’t influence on the peptidoglycane effect while the blocking of Gi/o-protein by the pertussis toxin caused stopping it’s manifestation. We concluded that the modulating effect of peptidoglycane implemented via Gi/o-protein activation, which causes adenilatcyclase desensitization.
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MESH Headings
- 8-Bromo Cyclic Adenosine Monophosphate/pharmacology
- Adenylyl Cyclases/genetics
- Adenylyl Cyclases/metabolism
- Adrenergic alpha-Agonists/pharmacology
- Adrenergic beta-2 Receptor Agonists
- Albuterol/pharmacology
- Animals
- Cell Wall/chemistry
- Cholera Toxin/pharmacology
- Colforsin/pharmacology
- Female
- GTP-Binding Protein alpha Subunits, Gi-Go/antagonists & inhibitors
- GTP-Binding Protein alpha Subunits, Gi-Go/genetics
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- GTP-Binding Protein alpha Subunits, Gs/antagonists & inhibitors
- GTP-Binding Protein alpha Subunits, Gs/genetics
- GTP-Binding Protein alpha Subunits, Gs/metabolism
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/physiology
- Myometrium/drug effects
- Myometrium/physiology
- Norepinephrine/pharmacology
- Papaverine/pharmacology
- Peptidoglycan/pharmacology
- Pertussis Toxin/pharmacology
- Rats
- Rats, Wistar
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Staphylococcus aureus/chemistry
- Tissue Culture Techniques
- Uterine Contraction/drug effects
- Uterine Contraction/physiology
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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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8
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Rothmeier AS, Marchese P, Langer F, Kamikubo Y, Schaffner F, Cantor J, Ginsberg MH, Ruggeri ZM, Ruf W. Tissue Factor Prothrombotic Activity Is Regulated by Integrin-arf6 Trafficking. Arterioscler Thromb Vasc Biol 2017; 37:1323-1331. [PMID: 28495929 DOI: 10.1161/atvbaha.117.309315] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 05/01/2017] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Coagulation initiation by tissue factor (TF) is regulated by cellular inhibitors, cell surface availability of procoagulant phosphatidylserine, and thiol-disulfide exchange. How these mechanisms contribute to keeping TF in a noncoagulant state and to generating prothrombotic TF remain incompletely understood. APPROACH AND RESULTS Here, we study the activation of TF in primary macrophages by a combination of pharmacological, genetic, and biochemical approaches. We demonstrate that primed macrophages effectively control TF cell surface activity by receptor internalization. After cell injury, ATP signals through the purinergic receptor P2rx7 induce release of TF+ microvesicles. TF cell surface availability for release onto microvesicles is regulated by the GTPase arf6 associated with integrin α4β1. Furthermore, microvesicles proteome analysis identifies activation of Gαi2 as a participating factor in the release of microvesicles with prothrombotic activity in flowing blood. ATP not only prevents TF and phosphatidylserine internalization but also induces TF conversion to a conformation with high affinity for its ligand, coagulation factor VII. Although inhibition of dynamin-dependent internalization also exposes outer membrane procoagulant phosphatidylserine, the resulting TF+ microvesicles distinctly lack protein disulfide isomerase and high affinity TF and fail to produce fibrin strands typical for microvesicles generated by thrombo-inflammatory P2rx7 activation. CONCLUSIONS These data show that procoagulant phospholipid exposure is not sufficient and that TF affinity maturation is required to generate prothrombotic microvesicles from a variety of cell types. These findings are significant for understanding TF-initiated thrombosis and should be considered in designing functional microvesicles-based diagnostic approaches.
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Affiliation(s)
- Andrea S Rothmeier
- From the Department of Immunology and Microbiology (A.S.R., F.S., W.R.) and Molecular Medicine (P.M., Y.K., Z.M.R.), The Scripps Research Institute, La Jolla, CA; II. Medical Clinic and Polyclinic, University Medical Center Eppendorf, Hamburg, Germany (F.L.); Department of Medicine, University of California San Diego, La Jolla (J.C., M.H.G.); Center for Thrombosis and Hemostasis, Johannes Gutenberg University Medical Center, Mainz, Germany (W.R.)
| | - Patrizia Marchese
- From the Department of Immunology and Microbiology (A.S.R., F.S., W.R.) and Molecular Medicine (P.M., Y.K., Z.M.R.), The Scripps Research Institute, La Jolla, CA; II. Medical Clinic and Polyclinic, University Medical Center Eppendorf, Hamburg, Germany (F.L.); Department of Medicine, University of California San Diego, La Jolla (J.C., M.H.G.); Center for Thrombosis and Hemostasis, Johannes Gutenberg University Medical Center, Mainz, Germany (W.R.)
| | - Florian Langer
- From the Department of Immunology and Microbiology (A.S.R., F.S., W.R.) and Molecular Medicine (P.M., Y.K., Z.M.R.), The Scripps Research Institute, La Jolla, CA; II. Medical Clinic and Polyclinic, University Medical Center Eppendorf, Hamburg, Germany (F.L.); Department of Medicine, University of California San Diego, La Jolla (J.C., M.H.G.); Center for Thrombosis and Hemostasis, Johannes Gutenberg University Medical Center, Mainz, Germany (W.R.)
| | - Yuichi Kamikubo
- From the Department of Immunology and Microbiology (A.S.R., F.S., W.R.) and Molecular Medicine (P.M., Y.K., Z.M.R.), The Scripps Research Institute, La Jolla, CA; II. Medical Clinic and Polyclinic, University Medical Center Eppendorf, Hamburg, Germany (F.L.); Department of Medicine, University of California San Diego, La Jolla (J.C., M.H.G.); Center for Thrombosis and Hemostasis, Johannes Gutenberg University Medical Center, Mainz, Germany (W.R.)
| | - Florence Schaffner
- From the Department of Immunology and Microbiology (A.S.R., F.S., W.R.) and Molecular Medicine (P.M., Y.K., Z.M.R.), The Scripps Research Institute, La Jolla, CA; II. Medical Clinic and Polyclinic, University Medical Center Eppendorf, Hamburg, Germany (F.L.); Department of Medicine, University of California San Diego, La Jolla (J.C., M.H.G.); Center for Thrombosis and Hemostasis, Johannes Gutenberg University Medical Center, Mainz, Germany (W.R.)
| | - Joseph Cantor
- From the Department of Immunology and Microbiology (A.S.R., F.S., W.R.) and Molecular Medicine (P.M., Y.K., Z.M.R.), The Scripps Research Institute, La Jolla, CA; II. Medical Clinic and Polyclinic, University Medical Center Eppendorf, Hamburg, Germany (F.L.); Department of Medicine, University of California San Diego, La Jolla (J.C., M.H.G.); Center for Thrombosis and Hemostasis, Johannes Gutenberg University Medical Center, Mainz, Germany (W.R.)
| | - Mark H Ginsberg
- From the Department of Immunology and Microbiology (A.S.R., F.S., W.R.) and Molecular Medicine (P.M., Y.K., Z.M.R.), The Scripps Research Institute, La Jolla, CA; II. Medical Clinic and Polyclinic, University Medical Center Eppendorf, Hamburg, Germany (F.L.); Department of Medicine, University of California San Diego, La Jolla (J.C., M.H.G.); Center for Thrombosis and Hemostasis, Johannes Gutenberg University Medical Center, Mainz, Germany (W.R.)
| | - Zaverio M Ruggeri
- From the Department of Immunology and Microbiology (A.S.R., F.S., W.R.) and Molecular Medicine (P.M., Y.K., Z.M.R.), The Scripps Research Institute, La Jolla, CA; II. Medical Clinic and Polyclinic, University Medical Center Eppendorf, Hamburg, Germany (F.L.); Department of Medicine, University of California San Diego, La Jolla (J.C., M.H.G.); Center for Thrombosis and Hemostasis, Johannes Gutenberg University Medical Center, Mainz, Germany (W.R.)
| | - Wolfram Ruf
- From the Department of Immunology and Microbiology (A.S.R., F.S., W.R.) and Molecular Medicine (P.M., Y.K., Z.M.R.), The Scripps Research Institute, La Jolla, CA; II. Medical Clinic and Polyclinic, University Medical Center Eppendorf, Hamburg, Germany (F.L.); Department of Medicine, University of California San Diego, La Jolla (J.C., M.H.G.); Center for Thrombosis and Hemostasis, Johannes Gutenberg University Medical Center, Mainz, Germany (W.R.).
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9
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Jin M, Yu B, Zhang W, Zhang W, Xiao Z, Mao Z, Lai Y, Lin D, Ma Q, Pan E, Zhang Y, Yu Y. Toll-like receptor 2-mediated MAPKs and NF-κB activation requires the GNAO1-dependent pathway in human mast cells. Integr Biol (Camb) 2016; 8:968-75. [PMID: 27515449 DOI: 10.1039/c6ib00097e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Toll-like receptors (TLRs) expressed on mast cells are essential for effective host defense against a wide variety of pathogens. Previous studies have demonstrated that both TLR2 agonists Pam3CSK4 and PGN stimulated IL-8 release in human mast cells. To determine the molecular basis for this phenomenon, we utilized human mast cell line LAD2 cells. We found that only the release of IL-8 stimulated by Pam3CSK4 was TLR2-mediated, which was confirmed by specific TLR2 shRNA. Heterotrimeric G proteins have been previously implicated in TLR signaling in macrophages and monocytes. In the current study, we showed that PamCSK4 induced the activation of MAPKs, NF-κB, PI3K-Akt and Ca(2+)-calcineurin-NFAT signaling cascades in LAD2 cells. Go proteins were required for the activation of MAPKs and NF-κB in TLR2 stimulated LAD2 cells. Therefore, the genetic depletion of Gαo proteins also led to the reduction of the release of IL-8 in LAD2 cells. Taken together, the data presented here suggest that TLR2 activation in human mast cells promotes the release of inflammatory mediators via distinct signaling pathways that partially depend on the action of Go proteins.
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Affiliation(s)
- Meiling Jin
- Center for Diabetes, Obesity and Metabolism, Department of Physiology, Shenzhen University Health Science Center, Shenzhen, Guangdong province 518060, China.
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10
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Toropova MA, Veselinović AM, Veselinović JB, Stojanović DB, Toropov AA. QSAR modeling of the antimicrobial activity of peptides as a mathematical function of a sequence of amino acids. Comput Biol Chem 2015; 59 Pt A:126-30. [DOI: 10.1016/j.compbiolchem.2015.09.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 08/04/2015] [Accepted: 09/15/2015] [Indexed: 01/29/2023]
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11
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Farrag M, Laufenberg LJ, Steiner JL, Weller GE, Lang CH, Ruiz-Velasco V. Modulation of voltage-gated Ca2+ channels by G protein-coupled receptors in celiac-mesenteric ganglion neurons of septic rats. PLoS One 2015; 10:e0125566. [PMID: 26017846 PMCID: PMC4446366 DOI: 10.1371/journal.pone.0125566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 03/25/2015] [Indexed: 12/25/2022] Open
Abstract
Septic shock, the most severe complication associated with sepsis, is manifested by tissue hypoperfusion due, in part, to cardiovascular and autonomic dysfunction. In many cases, the splanchnic circulation becomes vasoplegic. The celiac-superior mesenteric ganglion (CSMG) sympathetic neurons provide the main autonomic input to these vessels. We used the cecal ligation puncture (CLP) model, which closely mimics the hemodynamic and metabolic disturbances observed in septic patients, to examine the properties and modulation of Ca2+ channels by G protein-coupled receptors in acutely dissociated rat CSMG neurons. Voltage-clamp studies 48 hr post-sepsis revealed that the Ca2+ current density in CMSG neurons from septic rats was significantly lower than those isolated from sham control rats. This reduction coincided with a significant increase in membrane surface area and a negligible increase in Ca2+ current amplitude. Possible explanations for these findings include either cell swelling or neurite outgrowth enhancement of CSMG neurons from septic rats. Additionally, a significant rightward shift of the concentration-response relationship for the norepinephrine (NE)-mediated Ca2+ current inhibition was observed in CSMG neurons from septic rats. Testing for the presence of opioid receptor subtypes in CSMG neurons, showed that mu opioid receptors were present in ~70% of CSMG, while NOP opioid receptors were found in all CSMG neurons tested. The pharmacological profile for both opioid receptor subtypes was not significantly affected by sepsis. Further, the Ca2+ current modulation by propionate, an agonist for the free fatty acid receptors GPR41 and GPR43, was not altered by sepsis. Overall, our findings suggest that CSMG function is affected by sepsis via changes in cell size and α2-adrenergic receptor-mediated Ca2+ channel modulation.
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Affiliation(s)
- Mohamed Farrag
- Department of Anesthesiology, Penn State College of Medicine, Hershey, PA, United States of America
| | - Lacee J. Laufenberg
- Department of Surgery, Penn State College of Medicine, Hershey, PA, United States of America
| | - Jennifer L. Steiner
- Department of Cellular & Molecular Physiology, Penn State College of Medicine, Hershey, PA, United States of America
| | - Gregory E. Weller
- Department of Anesthesiology, Penn State College of Medicine, Hershey, PA, United States of America
| | - Charles H. Lang
- Department of Cellular & Molecular Physiology, Penn State College of Medicine, Hershey, PA, United States of America
| | - Victor Ruiz-Velasco
- Department of Anesthesiology, Penn State College of Medicine, Hershey, PA, United States of America
- * E-mail:
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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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Lau C, Nygård S, Fure H, Olstad OK, Holden M, Lappegård KT, Brekke OL, Espevik T, Hovig E, Mollnes TE. CD14 and complement crosstalk and largely mediate the transcriptional response to Escherichia coli in human whole blood as revealed by DNA microarray. PLoS One 2015; 10:e0117261. [PMID: 25706641 PMCID: PMC4338229 DOI: 10.1371/journal.pone.0117261] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 12/20/2014] [Indexed: 12/22/2022] Open
Abstract
Systemic inflammation like in sepsis is still lacking specific diagnostic markers and effective therapeutics. The first line of defense against intruding pathogens and endogenous damage signals is pattern recognition by e.g., complement and Toll-like receptors (TLR). Combined inhibition of a key complement component (C3 and C5) and TLR-co-receptor CD14 has been shown to attenuate certain systemic inflammatory responses. Using DNA microarray and gene annotation analyses, we aimed to decipher the effect of combined inhibition of C3 and CD14 on the transcriptional response to bacterial challenge in human whole blood. Importantly, combined inhibition reversed the transcriptional changes of 70% of the 2335 genes which significantly responded to heat-inactivated Escherichia coli by on average 80%. Single inhibition was less efficient (p<0.001) but revealed a suppressive effect of C3 on 21% of the responding genes which was partially counteracted by CD14. Furthermore, CD14 dependency of the Escherichia coli-induced response was increased in C5-deficient compared to C5-sufficient blood. The observed crucial distinct and synergistic roles for complement and CD14 on the transcriptional level correspond to their broad impact on the inflammatory response in human blood, and their combined inhibition may become inevitable in the early treatment of acute systemic inflammation.
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Affiliation(s)
- Corinna Lau
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital, Bodø, Norway
- * E-mail:
| | - Ståle Nygård
- Department of Informatics, University of Oslo, Oslo, Norway
- Bioinformatics Core Facility and Institute for Medical Informatics, Oslo University Hospital, Oslo, Norway
| | - Hilde Fure
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital, Bodø, Norway
| | | | | | - Knut Tore Lappegård
- Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
- Division of Medicine, Nordland Hospital, Bodø, Norway
| | - Ole-Lars Brekke
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital, Bodø, Norway
- Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
| | - Terje Espevik
- Center of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Eivind Hovig
- Department of Informatics, University of Oslo, Oslo, Norway
- Bioinformatics Core Facility and Institute for Medical Informatics, Oslo University Hospital, Oslo, Norway
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
- Department of Cancer Genetics and Informatics, Oslo University Hospital, Oslo, Norway
| | - Tom Eirik Mollnes
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital, Bodø, Norway
- Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
- Center of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
- Institute of Immunology, Oslo University Hospital Rikshospitalet and University of Oslo, Oslo, Norway
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Español AJ, Maddaleno MO, Lombardi MG, Cella M, Martínez Pulido P, Sales ME. Treatment with LPS plus INF-γ induces the expression and function of muscarinic acetylcholine receptors, modulating NIH3T3 cell proliferation: participation of NOS and COX. Br J Pharmacol 2014; 171:5154-67. [PMID: 24990429 DOI: 10.1111/bph.12834] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 06/17/2014] [Accepted: 06/24/2014] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND AND PURPOSE LPS and IFN-γ are potent stimuli of inflammation, a process in which fibroblasts are frequently involved. We analysed the effect of treatment with LPS plus IFN-γ on the expression and function of muscarinic acetylcholine receptors in NIH3T3 fibroblasts with regards to proliferation of these cells. We also investigated the participation of NOS and COX, and the role of NF-κB in this process. EXPERIMENTAL APPROACH NIH3T3 cells were treated with LPS (10 ng·mL(-1)) plus IFN-γ (0.5 ng·mL(-1)) for 72 h (iNIH3T3 cells). Cell proliferation was evaluated with MTT and protein expression by Western blot analysis. NOS and COX activities were measured by the Griess method and radioimmunoassay respectively. KEY RESULTS The cholinoceptor agonist carbachol was more effective at stimulating proliferation in iNIH3T3 than in NIH3T3 cells, probably due to the de novo induction of M3 and M5 muscarinic receptors independently of NF-κB activation. iNIH3T3 cells produced higher amounts of NO and PGE2 than NIH3T3 cells, concomitantly with an up-regulation of NOS1 and COX-2, and with the de novo induction of NOS2/3 in inflamed cells. We also found a positive feedback between NOS and COX that could potentiate inflammation. CONCLUSIONS AND IMPLICATIONS Inflammation induced the expression of muscarinic receptors and, therefore,stimulated carbachol-induced proliferation of fibroblasts. Inflammation also up-regulated the expression of NOS and COX-2, thus potentiating the effect of carbachol on NO and PGE2 production. A positive crosstalk between NOS and COX triggered by carbachol in inflamed cells points to muscarinic receptors as potential therapeutic targets in inflammation.
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Affiliation(s)
- A J Español
- Facultad de Medicina, Universidad de Buenos Aires, Centro de Estudios Farmacológicos y Botánicos (CEFYBO)-CONICET, Buenos Aires, Argentina
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15
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Balenga NA, Jester W, Jiang M, Panettieri RA, Druey KM. Loss of regulator of G protein signaling 5 promotes airway hyperresponsiveness in the absence of allergic inflammation. J Allergy Clin Immunol 2014; 134:451-9. [PMID: 24666695 PMCID: PMC4119844 DOI: 10.1016/j.jaci.2014.01.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 01/24/2014] [Accepted: 01/27/2014] [Indexed: 12/13/2022]
Abstract
BACKGROUND Although eosinophilic inflammation typifies allergic asthma, it is not a prerequisite for airway hyperresponsiveness (AHR), suggesting that underlying abnormalities in structural cells, such as airway smooth muscle (ASM), contribute to the asthmatic diathesis. Dysregulation of procontractile G protein-coupled receptor (GPCR) signaling in ASM could mediate enhanced contractility. OBJECTIVE We explored the role of a regulator of procontractile GPCR signaling, regulator of G protein signaling 5 (RGS5), in unprovoked and allergen-induced AHR. METHODS We evaluated GPCR-evoked Ca(2+) signaling, precision-cut lung slice (PCLS) contraction, and lung inflammation in naive and Aspergillus fumigatus-challenged wild-type and Rgs5(-/-) mice. We analyzed lung resistance and dynamic compliance in live anesthetized mice using invasive plethysmography. RESULTS Loss of RGS5 promoted constitutive AHR because of enhanced GPCR-induced Ca(2+) mobilization in ASM. PCLSs from naive Rgs5(-/-) mice contracted maximally at baseline independently of allergen challenge. RGS5 deficiency had little effect on the parameters of allergic inflammation, including cell counts in bronchoalveolar lavage fluid, mucin production, ASM mass, and subepithelial collagen deposition. Unexpectedly, induced IL-13 and IL-33 levels were much lower in challenged lungs from Rgs5(-/-) mice relative to those seen in wild-type mice. CONCLUSION Loss of RGS5 confers spontaneous AHR in mice in the absence of allergic inflammation. Because it is selectively expressed in ASM within the lung and does not promote inflammation, RGS5 might be a therapeutic target for asthma.
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Affiliation(s)
- Nariman A Balenga
- Molecular Signal Transduction Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases/National Institutes of Health, Bethesda, Md
| | - William Jester
- Pulmonary, Allergy and Critical Care Division, Airways Biology Initiative, University of Pennsylvania, Philadelphia, Pa
| | - Meiqi Jiang
- Pulmonary, Allergy and Critical Care Division, Airways Biology Initiative, University of Pennsylvania, Philadelphia, Pa
| | - Reynold A Panettieri
- Pulmonary, Allergy and Critical Care Division, Airways Biology Initiative, University of Pennsylvania, Philadelphia, Pa
| | - Kirk M Druey
- Molecular Signal Transduction Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases/National Institutes of Health, Bethesda, Md.
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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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Hildebrand D, Sahr A, Wölfle SJ, Heeg K, Kubatzky KF. Regulation of Toll-like receptor 4-mediated immune responses through Pasteurella multocida toxin-induced G protein signalling. Cell Commun Signal 2012; 10:22. [PMID: 22852877 PMCID: PMC3441383 DOI: 10.1186/1478-811x-10-22] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 07/20/2012] [Indexed: 12/24/2022] Open
Abstract
Background Lipopolysaccharide (LPS)-triggered Toll-like receptor (TLR) 4-signalling belongs to the key innate defence mechanisms upon infection with Gram-negative bacteria and triggers the subsequent activation of adaptive immunity. There is an active crosstalk between TLR4-mediated and other signalling cascades to secure an effective immune response, but also to prevent excessive inflammation. Many pathogens induce signalling cascades via secreted factors that interfere with TLR signalling to modify and presumably escape the host response. In this context heterotrimeric G proteins and their coupled receptors have been recognized as major cellular targets. Toxigenic strains of Gram-negative Pasteurella multocida produce a toxin (PMT) that constitutively activates the heterotrimeric G proteins Gαq, Gα13 and Gαi independently of G protein-coupled receptors through deamidation. PMT is known to induce signalling events involved in cell proliferation, cell survival and cytoskeleton rearrangement. Results Here we show that the activation of heterotrimeric G proteins through PMT suppresses LPS-stimulated IL-12p40 production and eventually impairs the T cell-activating ability of LPS-treated monocytes. This inhibition of TLR4-induced IL-12p40 expression is mediated by Gαi-triggered signalling as well as by Gβγ-dependent activation of PI3kinase and JNK. Taken together we propose the following model: LPS stimulates TLR4-mediated activation of the NFĸB-pathway and thereby the production of TNF-α, IL-6 and IL-12p40. PMT inhibits the production of IL-12p40 by Gαi-mediated inhibition of adenylate cyclase and cAMP accumulation and by Gβγ-mediated activation of PI3kinase and JNK activation. Conclusions On the basis of the experiments with PMT this study gives an example of a pathogen-induced interaction between G protein-mediated and TLR4-triggered signalling and illustrates how a bacterial toxin is able to interfere with the host’s immune response.
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Affiliation(s)
- Dagmar Hildebrand
- Department für Infektiologie, Medizinische Mikrobiologie und Hygiene, Im Neuenheimer, Feld 324, D-69120, Heidelberg, Germany.
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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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Avram S, Buiu C, Borcan F, Milac AL. More effective antimicrobial mastoparan derivatives, generated by 3D-QSAR-Almond and computational mutagenesis. ACTA ACUST UNITED AC 2012; 8:587-94. [DOI: 10.1039/c1mb05297g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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