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Khan MM, Ernst O, Manes NP, Oyler BL, Fraser IDC, Goodlett DR, Nita-Lazar A. Multi-Omics Strategies Uncover Host-Pathogen Interactions. ACS Infect Dis 2019; 5:493-505. [PMID: 30857388 DOI: 10.1021/acsinfecdis.9b00080] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
With the success of the Human Genome Project, large-scale systemic projects became a reality that enabled rapid development of the systems biology field. Systems biology approaches to host-pathogen interactions have been instrumental in the discovery of some specifics of Gram-negative bacterial recognition, host signal transduction, and immune tolerance. However, further research, particularly using multi-omics approaches, is essential to untangle the genetic, immunologic, (post)transcriptional, (post)translational, and metabolic mechanisms underlying progression from infection to clearance of microbes. The key to understanding host-pathogen interactions lies in acquiring, analyzing, and modeling multimodal data obtained through integrative multi-omics experiments. In this article, we will discuss how multi-omics analyses are adding to our understanding of the molecular basis of host-pathogen interactions and systemic maladaptive immune response of the host to microbes and microbial products.
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Affiliation(s)
- Mohd M. Khan
- Laboratory of Immune System Biology (LISB), National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), 9000 Rockville Pike, Bethesda, Maryland 20814, United States
- University of Maryland School of Medicine, 655 W. Baltimore Street, Baltimore, Maryland 21201, United States
| | - Orna Ernst
- Laboratory of Immune System Biology (LISB), National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), 9000 Rockville Pike, Bethesda, Maryland 20814, United States
| | - Nathan P. Manes
- Laboratory of Immune System Biology (LISB), National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), 9000 Rockville Pike, Bethesda, Maryland 20814, United States
| | - Benjamin L. Oyler
- University of Maryland School of Medicine, 655 W. Baltimore Street, Baltimore, Maryland 21201, United States
| | - Iain D. C. Fraser
- Laboratory of Immune System Biology (LISB), National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), 9000 Rockville Pike, Bethesda, Maryland 20814, United States
| | - David R. Goodlett
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 North Pine Street, Baltimore, Maryland 21201, United States
| | - Aleksandra Nita-Lazar
- Laboratory of Immune System Biology (LISB), National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), 9000 Rockville Pike, Bethesda, Maryland 20814, United States
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Emerging and Dynamic Biomedical Uses of Ferritin. Pharmaceuticals (Basel) 2018; 11:ph11040124. [PMID: 30428583 PMCID: PMC6316788 DOI: 10.3390/ph11040124] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 11/11/2018] [Accepted: 11/12/2018] [Indexed: 12/14/2022] Open
Abstract
Ferritin, a ubiquitously expressed protein, has classically been considered the main iron cellular storage molecule in the body. Owing to the ferroxidase activity of the H-subunit and the nucleation ability of the L-subunit, ferritin can store a large amount of iron within its mineral core. However, recent evidence has demonstrated a range of abilities of ferritin that extends well beyond the scope of iron storage. This review aims to discuss novel functions and biomedical uses of ferritin in the processes of iron delivery, delivery of biologics such as chemotherapies and contrast agents, and the utility of ferritin as a biomarker in a number of neurological diseases.
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Mass Spectrometry-based Structural Analysis and Systems Immunoproteomics Strategies for Deciphering the Host Response to Endotoxin. J Mol Biol 2018; 430:2641-2660. [PMID: 29949751 DOI: 10.1016/j.jmb.2018.06.032] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/23/2018] [Accepted: 06/15/2018] [Indexed: 02/06/2023]
Abstract
One cause of sepsis is systemic maladaptive immune response of the host to bacteria and specifically, to Gram-negative bacterial outer-membrane glycolipid lipopolysaccharide (LPS). On the host myeloid cell surface, proinflammatory LPS activates the innate immune system via Toll-like receptor-4/myeloid differentiation factor-2 complex. Intracellularly, LPS is also sensed by the noncanonical inflammasome through caspase-11 in mice and 4/5 in humans. The minimal functional determinant for innate immune activation is the membrane anchor of LPS called lipid A. Even subtle modifications to the lipid A scaffold can enable, diminish, or abolish immune activation. Bacteria are known to modify their LPS structure during environmental stress and infection of hosts to alter cellular immune phenotypes. In this review, we describe how mass spectrometry-based structural analysis of endotoxin helped uncover major determinations of molecular pathogenesis. Through characterization of LPS modifications, we now better understand resistance to antibiotics and cationic antimicrobial peptides, as well as how the environment impacts overall endotoxin structure. In addition, mass spectrometry-based systems immunoproteomics approaches can assist in elucidating the immune response against LPS. Many regulatory proteins have been characterized through proteomics and global/targeted analysis of protein modifications, enabling the discovery and characterization of novel endotoxin-mediated protein translational modifications.
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Sjoelund V, Smelkinson M, Nita-Lazar A. Phosphoproteome profiling of the macrophage response to different toll-like receptor ligands identifies differences in global phosphorylation dynamics. J Proteome Res 2014; 13:5185-97. [PMID: 24941444 PMCID: PMC4227906 DOI: 10.1021/pr5002466] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
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Toll-like
receptors (TLRs) are among the first sensors that detect
infection and drive immune response. Macrophages encountering a pathogen
are usually stimulated not by one TLR, but by a combination of TLRs
engaged by distinct microbe ligands. To understand the integrated
signaling under complex conditions, we investigated the differences
in the phosphoprotein signaling cascades triggered by TLR2, TLR4,
and TLR7 ligands using a single responding cell population. We performed
a global, quantitative, early poststimulation kinetic analysis of
the mouse macrophage phosphoproteome using stable isotope labeling
with amino acids coupled to phosphopeptide enrichment and high-resolution
mass spectrometry. For each TLR ligand, we found marked elevation
of phosphorylation of cytoskeleton components, GTPases of the Rho
family, and phospholipase C signaling pathway proteins. Phosphorylation
of proteins involved in phagocytosis was only seen in response to
TLR2 and TLR4 but not to TLR7 activation. Changes in the phosphorylation
of proteins involved in endocytosis were delayed in response to TLR2
as compared to TLR4 ligands. These findings reveal that the phosphoproteomic
response to stimulation of distinct TLRs varies both in the major
modification targets and the phosphorylation dynamics. These results
advance the understanding of how macrophages sense and respond to
a diverse set of TLR stimuli.
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Affiliation(s)
- Virginie Sjoelund
- Laboratory of Systems Biology, and §Research Technology Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bethesda, Maryland 20892, United States
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Wang H, Dong D, Tang S, Chen X, Gao Q. PPE38 of Mycobacterium marinum triggers the cross-talk of multiple pathways involved in the host response, as revealed by subcellular quantitative proteomics. J Proteome Res 2013; 12:2055-66. [PMID: 23514422 PMCID: PMC3646403 DOI: 10.1021/pr301017e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
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The
PE/PPE family of proteins which are in high abundance in pathogenic
species such as Mycobacterium tuberculosis and M. marinum, play the critical
role in generating antigenic variation and evasion of host immune
responses. However, little is known about their functional roles in
mycobacterial pathogenesis. Previously, we found that PPE38 is associated
with the virulence of mycobacteria, presumably by modulating the host
immune response. To clarify the link between PPE38 and host response,
we employed a subcellular, amino acid-coded mass tagging (AACT)/SILAC-based
quantitative proteomic approach to determine the proteome changes
during host response to M. marinum PPE38.
As a result, 291 or 290 proteins were found respectively to be up-
or down-regulated in the nucleus. Meanwhile, 576 upregulated and 272
downregulated proteins were respectively detected in the cytosol.
The data of quantitative proteomic changes and concurrent biological
validations revealed that M. marinum PPE38 could trigger extensive inflammatory responses in macrophages,
probably through interacting with toll-like receptor 2 (TLR2). We
also found that PPE38 may arrest MHC-1 processing and presentation
in infected macrophages. Using bioinformatics tools to analyze global
changes in the host proteome, we obtained a PPE38-respondor network involved in various transcriptional factors (TFs) and TF-associated
proteins. The results of our systems investigation now indicate that there is cross-talk involving a broad range of diverse biological pathways/processes that coordinate the host response to M. marinum PPE38.
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Affiliation(s)
- Hui Wang
- Key Laboratory of Medical Molecular Virology, Institute of Biomedical Sciences and Institute of Medical Microbiology, Shanghai Medical College, Fudan University, Shanghai 200032, China
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Lee YY, Yu YB, Gunawardena HP, Xie L, Chen X. BCLAF1 is a radiation-induced H2AX-interacting partner involved in γH2AX-mediated regulation of apoptosis and DNA repair. Cell Death Dis 2012; 3:e359. [PMID: 22833098 PMCID: PMC3406578 DOI: 10.1038/cddis.2012.76] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
H2AX, a histone H2A variant, has a key role in the cellular response to DNA double-strand breaks (DSBs). H2AX senses DSBs through rapid serine 139 phosphorylation, concurrently leading to the formation of phospho-(γ)H2AX foci with various proteins. However, in the cells with different sensitivity to ionizing radiation (IR)-induced DSBs, still incomplete are those specific proteins selectively recruited by γH2AX to decide different cell fates. Because the abundance of γH2AX indicates the extent of DSBs, we first identified IR-induced dose-dependent H2AX-interacting partners and found that Bcl-2-associated transcription factor 1 (BCLAF1/Btf) showed enhanced association with γH2AX only under high-dose radiation. In acutely irradiated cells, BCLAF1 promoted apoptosis of irreparable cells through disturbing p21-mediated inhibition of Caspase/cyclin E-dependent, mitochondrial-mediated pathways. Meanwhile, BCLAF1 co-localized with γH2AX foci in nuclei and stabilized the Ku70/DNA-PKcs complex therein, facilitating non-homologous end joining (NHEJ)-based DSB repair in surviving cells. In tumor cells, BCLAF1 was intrinsically suppressed, leading to formation of anti-apoptotic Ku70-Bax complexes and disruption of Ku70/DNA-PKcs complexes, all of which contribute to tumor-associated apoptotic resistance and cell survival with defective NHEJ DNA repair. For the first time, our studies reveal that, based on the extent of DNA damage, BCLAF1 is involved in the γH2AX-mediated regulation of apoptosis and DNA repair, and is a γH2AX-interacting tumor suppressor.
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Affiliation(s)
- Y Y Lee
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Oliveira RAS, Correia-Oliveira J, Tang LJ, Garcia RC. A proteomic insight into the effects of the immunomodulatory hydroxynaphthoquinone lapachol on activated macrophages. Int Immunopharmacol 2012; 14:54-65. [PMID: 22705049 DOI: 10.1016/j.intimp.2012.05.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2012] [Revised: 05/29/2012] [Accepted: 05/29/2012] [Indexed: 12/31/2022]
Abstract
We report the effect of an immunomodulatory and anti-mycobacterial naphthoquinone, lapachol, on the bi-dimensional patterns of protein expression of toll-like receptor 2 (TLR2)-agonised and IFN-γ-treated THP-1 macrophages. This non-hypothesis driven proteomic analysis intends to shed light on the cellular functions lapachol may be affecting. Proteins of both cytosol and membrane fractions were analysed. After quantification of the protein spots, the protein levels corresponding to macrophages activated in the absence or presence of lapachol were compared. A number of proteins were identified, the levels of which were appreciably and significantly increased or decreased as a result of the action of lapachol on the activated macrophages: cofilin-1, fascin, plastin-2, glucose-6-P-dehydrogenase, adenylyl cyclase-associated protein 1, pyruvate kinase, sentrin-specific protease 6, cathepsin B, cathepsin D, cytosolic aminopeptidase, proteasome β type-4 protease, tryptophan-tRNA ligase, DnaJ homolog and protein disulphide isomerase. Altogether, the comparative analysis performed indicates that lapachol could be hypothetically causing an impairment of cell migration and/or phagocytic capacity, an increase in NADPH availability, a decrease in pyruvate concentration, protection from proteosomal protein degradation, a decrease in lysosomal protein degradation, an impairment of cytosolic peptide generation, and an interference with NOS2 activation and grp78 function. The present proteomic results suggest issues that should be experimentally addressed ex- and in-vivo, to establish more accurately the potential of lapachol as an anti-infective drug. This study also constitutes a model for the pre-in-vivo evaluation of drug actions.
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Affiliation(s)
- Renato A S Oliveira
- Leukocyte Biology Group, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy.
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Kraft-Terry SD, Engebretsen IL, Bastola DK, Fox HS, Ciborowski P, Gendelman HE. Pulsed stable isotope labeling of amino acids in cell culture uncovers the dynamic interactions between HIV-1 and the monocyte-derived macrophage. J Proteome Res 2011; 10:2852-62. [PMID: 21500866 PMCID: PMC3108467 DOI: 10.1021/pr200124j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
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Dynamic interactions between human immunodeficiency virus-1 (HIV-1) and the macrophage govern the tempo of viral dissemination and replication in its human host. HIV-1 affects macrophage phenotype, and the macrophage, in turn, can modulate the viral life cycle. While these processes are linked to host–cell function and survival, the precise intracellular pathways involved are incompletely understood. To elucidate such dynamic virus–cell events, we employed pulsed stable isotope labeling of amino acids in cell culture. Alterations in de novo protein synthesis of HIV-1 infected human monocyte-derived macrophages (MDM) were examined after 3, 5, and 7 days of viral infection. Synthesis rates of cellular metabolic, regulatory, and DNA packaging activities were decreased, whereas, those affecting antigen presentation (major histocompatibility complex I and II) and interferon-induced antiviral activities were increased. Interestingly, enrichment of proteins linked to chromatin assembly or disassembly, DNA packaging, and nucleosome assembly were identified that paralleled virus-induced cytopathology and replication. We conclude that HIV-1 regulates a range of host MDM proteins that affect its survival and abilities to contain infection. Pulsed stable isotope labeling of amino acids in cell culture enables studies of alterations in human monocyte-derived macrophages (MDM) following human immunodeficiency virus type one (HIV-1) infection. De novo synthesis of HIV-1 infected MDM proteins examined 3−7 days after infection demonstrated alterations in protein synthesis kinetics linked to interferon-induced antiviral activities, DNA packaging, transcriptional regulation, and antigen presentation. These paralleled increases in viral production and cytopathicity.
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Affiliation(s)
- Stephanie D Kraft-Terry
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska 68198-5880, USA
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Meléndez LM, Colon K, Rivera L, Rodriguez-Franco E, Toro-Nieves D. Proteomic analysis of HIV-infected macrophages. J Neuroimmune Pharmacol 2011; 6:89-106. [PMID: 21153888 PMCID: PMC3028070 DOI: 10.1007/s11481-010-9253-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 11/23/2010] [Indexed: 12/21/2022]
Abstract
Mononuclear phagocytes (monocytes, macrophages, and microglia) play an important role in innate immunity against pathogens including HIV. These cells are also important viral reservoirs in the central nervous system and secrete inflammatory mediators and toxins that affect the tissue environment and function of surrounding cells. In the era of antiretroviral therapy, there are fewer of these inflammatory mediators. Proteomic approaches including surface enhancement laser desorption ionization, one- and two-dimensional difference in gel electrophoresis, and liquid chromatography tandem mass spectrometry have been used to uncover the proteins produced by in vitro HIV-infected monocytes, macrophages, and microglia. These approaches have advanced the understanding of novel mechanisms for HIV replication and neuronal damage. They have also been used in tissue macrophages that restrict HIV replication to understand the mechanisms of restriction for future therapies. In this review, we summarize the proteomic studies on HIV-infected mononuclear phagocytes and discuss other recent proteomic approaches that are starting to be applied to this field. As proteomic instruments and methods evolve to become more sensitive and quantitative, future studies are likely to identify more proteins that can be targeted for diagnosis or therapy and to uncover novel disease mechanisms.
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Affiliation(s)
- Loyda M Meléndez
- Department of Microbiology and Medical Zoology, School of Medicine, University of Puerto Rico, San Juan 00935, Puerto Rico.
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Effect of Toll-like receptor 4 inhibitor on LPS-induced lung injury. Inflamm Res 2010; 59:837-45. [PMID: 20387088 DOI: 10.1007/s00011-010-0195-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 12/25/2009] [Accepted: 03/29/2010] [Indexed: 10/19/2022] Open
Abstract
OBJECTIVE AND DESIGN Toll-like receptor 4 (TLR4) plays important roles in the recognition of lipopolysaccharide (LPS) and the activation of inflammatory cascade. In this study, we evaluated the effect of TAK-242, a selective TLR4 signal transduction inhibitor, on acute lung injury (ALI). MATERIALS AND METHODS C57BL/6J mice were intravenously treated with TAK-242 15 min before the intratracheal administration of LPS or Pam3CSK4, a synthetic lipopeptide. Six hours after the challenge, bronchoalveolar lavage fluid was obtained for a differential cell count and the measurement of cytokine and myeloperoxidase levels. Lung permeability and nuclear factor-kappaB (NF-kappaB) DNA binding activity were also evaluated. RESULTS TAK-242 effectively attenuated the neutrophil accumulation and activation in the lungs, the increase in lung permeability, production of inflammatory mediators, and NF-kappaB DNA-binding activity induced by the LPS challenge. In contrast, TAK-242 did not suppress inflammatory changes induced by Pam3CSK4. CONCLUSION TAK-242 may be a promising therapeutic agent for ALI, especially injuries associated with pneumonia caused by Gram-negative bacteria.
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Du R, Long J, Yao J, Dong Y, Yang X, Tang S, Zuo S, He Y, Chen X. Subcellular Quantitative Proteomics Reveals Multiple Pathway Cross-Talk That Coordinates Specific Signaling and Transcriptional Regulation for the Early Host Response to LPS. J Proteome Res 2010; 9:1805-21. [DOI: 10.1021/pr900962c] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Ruyun Du
- Department of Chemistry and Institute of Biomedical Sciences, Fudan University, Shanghai, China, and Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, North Carolina
| | - Jing Long
- Department of Chemistry and Institute of Biomedical Sciences, Fudan University, Shanghai, China, and Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, North Carolina
| | - Jun Yao
- Department of Chemistry and Institute of Biomedical Sciences, Fudan University, Shanghai, China, and Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, North Carolina
| | - Yun Dong
- Department of Chemistry and Institute of Biomedical Sciences, Fudan University, Shanghai, China, and Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, North Carolina
| | - Xiaoli Yang
- Department of Chemistry and Institute of Biomedical Sciences, Fudan University, Shanghai, China, and Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, North Carolina
| | - Siwei Tang
- Department of Chemistry and Institute of Biomedical Sciences, Fudan University, Shanghai, China, and Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, North Carolina
| | - Shuai Zuo
- Department of Chemistry and Institute of Biomedical Sciences, Fudan University, Shanghai, China, and Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, North Carolina
| | - Yufei He
- Department of Chemistry and Institute of Biomedical Sciences, Fudan University, Shanghai, China, and Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, North Carolina
| | - Xian Chen
- Department of Chemistry and Institute of Biomedical Sciences, Fudan University, Shanghai, China, and Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, North Carolina
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Bao H, Song P, Liu Q, Liu Y, Yun D, Saiyin H, Du R, Zhang Y, Fan H, Yang P, Chen X. Quantitative proteomic analysis of a paired human liver healthy versus carcinoma cell lines with the same genetic background to identify potential hepatocellular carcinoma markers. Proteomics Clin Appl 2009; 3:705-19. [DOI: 10.1002/prca.200780128] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Ey B, Eyking A, Gerken G, Podolsky DK, Cario E. TLR2 mediates gap junctional intercellular communication through connexin-43 in intestinal epithelial barrier injury. J Biol Chem 2009; 284:22332-22343. [PMID: 19528242 DOI: 10.1074/jbc.m901619200] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Gap junctional intercellular communication (GJIC) coordinates cellular functions essential for sustaining tissue homeostasis; yet its regulation in the intestine is not well understood. Here, we identify a novel physiological link between Toll-like receptor (TLR) 2 and GJIC through modulation of Connexin-43 (Cx43) during acute and chronic inflammatory injury of the intestinal epithelial cell (IEC) barrier. Data from in vitro studies reveal that TLR2 activation modulates Cx43 synthesis and increases GJIC via Cx43 during IEC injury. The ulcerative colitis-associated TLR2-R753Q mutant targets Cx43 for increased proteasomal degradation, impairing TLR2-mediated GJIC during intestinal epithelial wounding. In vivo studies using mucosal RNA interference show that TLR2-mediated mucosal healing depends functionally on intestinal epithelial Cx43 during acute inflammatory stress-induced damage. Mice deficient in TLR2 exhibit IEC-specific alterations in Cx43, whereas administration of a TLR2 agonist protects GJIC by blocking accumulation of Cx43 and its hyperphosphorylation at Ser368 to prevent spontaneous chronic colitis in MDR1alpha-deficient mice. Finally, adding the TLR2 agonist to three-dimensional intestinal mucosa-like cultures of human biopsies preserves intestinal epithelial Cx43 integrity and polarization ex vivo. In conclusion, Cx43 plays an important role in innate immune control of commensal-mediated intestinal epithelial wound repair.
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Affiliation(s)
- Birgit Ey
- Division of Gastroenterology and Hepatology, University Hospital of Essen, and Medical School, University of Duisburg-Essen, 45147 Essen, Germany
| | - Annette Eyking
- Division of Gastroenterology and Hepatology, University Hospital of Essen, and Medical School, University of Duisburg-Essen, 45147 Essen, Germany
| | - Guido Gerken
- Division of Gastroenterology and Hepatology, University Hospital of Essen, and Medical School, University of Duisburg-Essen, 45147 Essen, Germany
| | - Daniel K Podolsky
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Elke Cario
- Division of Gastroenterology and Hepatology, University Hospital of Essen, and Medical School, University of Duisburg-Essen, 45147 Essen, Germany
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