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Rani A, Tanwar M, Verma TP, Patra P, Trivedi P, Kumar R, Jha HC. Understanding the role of membrane cholesterol upon Epstein Barr virus infection in astroglial cells. Front Immunol 2023; 14:1192032. [PMID: 37876925 PMCID: PMC10591182 DOI: 10.3389/fimmu.2023.1192032] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 09/21/2023] [Indexed: 10/26/2023] Open
Abstract
Background EBV infection has long been postulated to trigger multiple sclerosis (MS) and anti-EBV antibodies showed a consistent presence in MS patients. Previous reports from our group have shown that the EBV infects different brain cells. Entry of the virus in neuronal cells is assisted by several host factors including membrane cholesterol. By using an inhibitor, methyl-β-cyclodextrin (MβCD), we evaluated the role of membrane cholesterol in EBV infection and pathogenesis. Methodology The membrane cholesterol depleted cells were infected with EBV and its latent genes expression were assessed. Further, EBV-mediated downstream signalling molecules namely STAT3, RIP, NF-kB and TNF-α levels was checked at protein level along with spatial (periphery and nucleus) and temporal changes in biomolecular fingerprints with Raman microspectroscopy (RS). Results Upon treatment with MβCD, lmp1 and lmp2a suggested significant downregulation compared to EBV infection. Downstream molecules like STAT3 and RIP, exhibited a decrease in protein levels temporally upon exposure to MβCD while NF-kB levels were found to be increased. Further, the intensity of the Raman spectra exhibited an increase in triglycerides and fatty acids in the cytoplasm of EBV-infected LN-229 cells compared to MβCD+EBV. Likewise, the Raman peak width of cholesterol, lipid and fatty acids were found to be reduced in EBV-infected samples indicates elevation in the cholesterol specific moieties. In contrast, an opposite pattern was observed in the nucleus. Moreover, the ingenuity pathway analysis revealed protein molecules such as VLDLR, MBP and APP that are associated with altered profile of cholesterol, fatty acids and triglycerides with infection-related CNS disorders. Conclusion Taken together, our results underline the important role of membrane cholesterol over EBV entry/pathogenesis in astroglia cells which further trigger/exacerbate virus-associated neuropathologies. These results likely to aid into the prognosis of neurological disease like MS.
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Affiliation(s)
- Annu Rani
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, India
| | - Manushree Tanwar
- Materials and Device Laboratory, Department of Physics, Indian Institute of Technology, Indore, India
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States
| | - Tarun Prakash Verma
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, India
| | - Priyanka Patra
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, India
| | - Pankaj Trivedi
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Rajesh Kumar
- Materials and Device Laboratory, Department of Physics, Indian Institute of Technology, Indore, India
| | - Hem Chandra Jha
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, India
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2
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Chen Y, Li G, Bhat OM, Li X, Zhang Y, Li PL. Impairment of Ceramide-Mediated Endothelial Instant Membrane Resealing During Diabetes Mellitus. Front Physiol 2022; 13:910339. [PMID: 35874544 PMCID: PMC9298829 DOI: 10.3389/fphys.2022.910339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 06/14/2022] [Indexed: 01/01/2023] Open
Abstract
Recent studies have indicated that instant cell membrane resealing (ICMR) controls the activation of NOD-like receptor pyrin domain containing 3 (Nlrp3) inflammasomes in endothelial cells, thereby initiating and promoting vascular inflammation. It remains unknown whether this impaired ICMR occurs under diabetic condition or hyperglycemia contributing to endothelial dysfunction leading to vascular inflammation, a hallmark of diabetic vascular injury. The present study aims to examine whether ICMR occurs during in control and diabetic mice and to explore related molecular mechanisms associated with acid sphingomyelinase (ASM)-mediated ceramide production. Using confocal microscopy, we demonstrated that mouse aortic endothelial cells (MAECs) exposed to high glucose levels exhibited much more retarded ICMR after laser-induced membrane injury, compared to that in control cells. The high glucose-induced impairment of membrane resealing in MAECs was prevented when these cells were pretreated with sphingomyelin or C24-ceramide. Mechanistically, high glucose treatment decreased association of membrane ceramide with annexin A5, an essential element of membrane repair machinery. Consistently, the association of ceramide with annexin A5 was significantly reduced in the coronary arterial endothelium of mice with streptozotocin-induced diabetes mellitus compared to that in non-diabetic control mice. Moreover, a marked reduction of the association of ceramide with annexin A5 was observed in coronary arterial endothelium of ASM knockout mice regardless of their diabetic status. Lastly, high glucose treatment or ASM gene deletion substantially impaired ICMR in coronary arterial endothelium of mice receiving membrane puncturing agents. Collectively, our data suggest that ceramide-mediated ICMR in vascular endothelial cells is impaired during diabetes mellitus due to dissociation of ceramide with annexin A5 and ASM play a critical role in this ICMR.
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Affiliation(s)
- Yang Chen
- School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Guangbi Li
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Owais M. Bhat
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Xiang Li
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, United States
| | - Yang Zhang
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, United States
| | - Pin-Lan Li
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
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3
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Guns J, Vanherle S, Hendriks JJA, Bogie JFJ. Protein Lipidation by Palmitate Controls Macrophage Function. Cells 2022; 11:cells11030565. [PMID: 35159374 PMCID: PMC8834383 DOI: 10.3390/cells11030565] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/03/2022] [Accepted: 02/04/2022] [Indexed: 01/27/2023] Open
Abstract
Macrophages are present in all tissues within our body, where they promote tissue homeostasis by responding to microenvironmental triggers, not only through clearance of pathogens and apoptotic cells but also via trophic, regulatory, and repair functions. To accomplish these divergent functions, tremendous dynamic fine-tuning of their physiology is needed. Emerging evidence indicates that S-palmitoylation, a reversible post-translational modification that involves the linkage of the saturated fatty acid palmitate to protein cysteine residues, directs many aspects of macrophage physiology in health and disease. By controlling protein activity, stability, trafficking, and protein–protein interactions, studies identified a key role of S-palmitoylation in endocytosis, inflammatory signaling, chemotaxis, and lysosomal function. Here, we provide an in-depth overview of the impact of S-palmitoylation on these cellular processes in macrophages in health and disease. Findings discussed in this review highlight the therapeutic potential of modulators of S-palmitoylation in immunopathologies, ranging from infectious and chronic inflammatory disorders to metabolic conditions.
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Affiliation(s)
- Jeroen Guns
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium; (J.G.); (S.V.); (J.J.A.H.)
- University MS Center, Hasselt University, 3500 Hasselt, Belgium
| | - Sam Vanherle
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium; (J.G.); (S.V.); (J.J.A.H.)
- University MS Center, Hasselt University, 3500 Hasselt, Belgium
| | - Jerome J. A. Hendriks
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium; (J.G.); (S.V.); (J.J.A.H.)
- University MS Center, Hasselt University, 3500 Hasselt, Belgium
| | - Jeroen F. J. Bogie
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium; (J.G.); (S.V.); (J.J.A.H.)
- University MS Center, Hasselt University, 3500 Hasselt, Belgium
- Correspondence: ; Tel.: +32-1126-9261
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4
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Glukhova XA, Trizna JA, Melnik BS, Proussakova OV, Beletsky IP. Recruitment of TNF ligands to lipid rafts is mediated by their physical association with caveolin-1. FEBS Lett 2022; 596:211-218. [PMID: 34897688 DOI: 10.1002/1873-3468.14257] [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: 10/20/2021] [Accepted: 10/29/2021] [Indexed: 11/08/2022]
Abstract
Activities of the tumour necrosis factor (TNF) family members are associated with their targeting to lipid rafts, specialised regions of the plasma membrane. Herein, we investigated the physical association of TNF and its family members cluster of differentiation 40 ligand (CD40L) and tumour necrosis factor-related apoptosis-inducing ligand with caveolin-1, a lipid raft resident protein. We discovered that the intracellular domains of TNF and CD40L interact with caveolin-1, and the membrane proximal region of TNF is required for the binding of caveolin-1 domains. Full-length TNF can form a complex with caveolin-1 in membrane rafts of HeLa cells, and caveolin-1 knockdown leads to impaired TNF transport to rafts. These findings provide the first evidence of a direct interaction between TNF, CD40L and caveolin-1 and suggest that caveolin-1 may be responsible for recruiting TNF to lipid rafts.
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Affiliation(s)
- Xenia A Glukhova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Puschino, Russia
| | - Julia A Trizna
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Puschino, Russia
| | - Bogdan S Melnik
- Institute of Protein Research, Russian Academy of Sciences, Puschino, Russia
| | - Olga V Proussakova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Puschino, Russia
| | - Igor P Beletsky
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Puschino, Russia
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5
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Lin H. Protein cysteine palmitoylation in immunity and inflammation. FEBS J 2021; 288:7043-7059. [PMID: 33506611 PMCID: PMC8872633 DOI: 10.1111/febs.15728] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/24/2020] [Accepted: 01/25/2021] [Indexed: 07/24/2023]
Abstract
Protein cysteine palmitoylation, or S-palmitoylation, has been known for about 40 years, and thousands of proteins in humans are known to be modified. Because of the large number of proteins modified, the importance and physiological functions of S-palmitoylation are enormous. However, most of the known physiological functions of S-palmitoylation can be broadly classified into two categories, neurological or immunological. This review provides a summary on the function of S-palmitoylation from the immunological perspective. Several important immune signaling pathways are discussed, including STING, NOD1/2, JAK-STAT in cytokine signaling, T-cell receptor signaling, chemotactic GPCR signaling, apoptosis, phagocytosis, and endothelial and epithelial integrity. This review is not meant to be comprehensive, but rather focuses on specific examples to highlight the versatility of palmitoylation in regulating immune signaling, as well as the potential and challenges of targeting palmitoylation to treat immune diseases.
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Affiliation(s)
- Hening Lin
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
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6
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Fritsch J, Särchen V, Schneider-Brachert W. Regulation of Death Receptor Signaling by S-Palmitoylation and Detergent-Resistant Membrane Micro Domains-Greasing the Gears of Extrinsic Cell Death Induction, Survival, and Inflammation. Cancers (Basel) 2021; 13:2513. [PMID: 34063813 PMCID: PMC8196677 DOI: 10.3390/cancers13112513] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 12/11/2022] Open
Abstract
Death-receptor-mediated signaling results in either cell death or survival. Such opposite signaling cascades emanate from receptor-associated signaling complexes, which are often formed in different subcellular locations. The proteins involved are frequently post-translationally modified (PTM) by ubiquitination, phosphorylation, or glycosylation to allow proper spatio-temporal regulation/recruitment of these signaling complexes in a defined cellular compartment. During the last couple of years, increasing attention has been paid to the reversible cysteine-centered PTM S-palmitoylation. This PTM regulates the hydrophobicity of soluble and membrane proteins and modulates protein:protein interaction and their interaction with distinct membrane micro-domains (i.e., lipid rafts). We conclude with which functional and mechanistic roles for S-palmitoylation as well as different forms of membrane micro-domains in death-receptor-mediated signal transduction were unraveled in the last two decades.
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Affiliation(s)
- Jürgen Fritsch
- Department of Infection Prevention and Infectious Diseases, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany;
| | - Vinzenz Särchen
- Institute for Experimental Cancer Research in Pediatrics, Goethe-University, 60528 Frankfurt, Germany;
| | - Wulf Schneider-Brachert
- Department of Infection Prevention and Infectious Diseases, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany;
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7
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Li J, Rao H, Bin Q, Fan YW, Li HY, Deng ZY. Linolelaidic acid induces apoptosis, cell cycle arrest and inflammation stronger than elaidic acid in human umbilical vein endothelial cells through lipid rafts. EUR J LIPID SCI TECH 2016. [DOI: 10.1002/ejlt.201600374] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Jing Li
- State Key Laboratory of Food Science and Technology; Nanchang University; Nanchang P. R. China
| | - Huan Rao
- State Key Laboratory of Food Science and Technology; Nanchang University; Nanchang P. R. China
- College of Food Science and Nutritional Engineering; China Agricultural University; Beijing P. R. China
| | - Qiu Bin
- State Key Laboratory of Food Science and Technology; Nanchang University; Nanchang P. R. China
- Institute of Agro-Food Science and Technology; Shandong Academy of Agricultural Sciences; Jinan P. R. China
| | - Ya-Wei Fan
- State Key Laboratory of Food Science and Technology; Nanchang University; Nanchang P. R. China
| | - Hong-Yan Li
- State Key Laboratory of Food Science and Technology; Nanchang University; Nanchang P. R. China
| | - Ze-Yuan Deng
- State Key Laboratory of Food Science and Technology; Nanchang University; Nanchang P. R. China
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8
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Li J, Das JR, Tang P, Han Z, Jaiswal JK, Ray PE. Transmembrane TNF- α Facilitates HIV-1 Infection of Podocytes Cultured from Children with HIV-Associated Nephropathy. J Am Soc Nephrol 2016; 28:862-875. [PMID: 27811066 DOI: 10.1681/asn.2016050564] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 09/02/2016] [Indexed: 12/11/2022] Open
Abstract
Studies have shown that podocytes and renal tubular epithelial cells from patients with HIV-associated nephropathy (HIVAN) express HIV-1 transcripts, suggesting that productive infection of renal epithelial cells precipitates development of HIVAN. However, podocytes and renal tubular epithelial cells do not express CD4 receptors, and it is unclear how these cells become productively infected in vivo We investigated the mechanisms underlying the infection by HIV-1 of podocytes cultured from the urine of children with HIVAN. We observed low-level productive infection on exposure of these cells to primary cell-free HIV-1 supernatants. However, envelope-defective recombinant HIV-1 did not infect the renal epithelial cell lines. Moreover, treatment of podocytes to inhibit endocytic transport or dynamin activity or remove cell surface heparan sulfate proteoglycans reduced infection efficiency. Transfection of CD4- 293T cells with a cDNA expression library developed from a podocyte cell line derived from a child with HIVAN led to the identification of TNF-α as a possible mediator of HIV-1 infection. Overexpression of transmembrane TNF-α in cultured CD4- renal tubular epithelial cells, 293T cells, and HeLa cells enabled the infection of these cells; exposure to soluble TNF-α did not. Immunohistochemistry showed TNF-α expression in podocytes of renal sections from children with HIVAN. Furthermore, we found that TNF-α enhanced NF-κB activation and integration of HIV-1 into the podocyte DNA. Finally, inhibition of dynamin activity blocked TNF-α-mediated infection. These data establish a role for transmembrane TNF-α in facilitating the viral entry and integration of HIV-1 into the DNA of renal epithelial cells.
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Affiliation(s)
- Jinliang Li
- Centers for *Genetic Medicine Research and.,Department of Pediatrics, and
| | - Jharna R Das
- Centers for *Genetic Medicine Research and.,Department of Pediatrics, and
| | - Pingtao Tang
- Centers for *Genetic Medicine Research and.,Department of Pediatrics, and
| | - Zhe Han
- Department of Pediatrics, and.,Cancer and Immunology
| | - Jyoti K Jaiswal
- Centers for *Genetic Medicine Research and.,Department of Pediatrics, and
| | - Patricio E Ray
- Centers for *Genetic Medicine Research and .,Department of Pediatrics, and.,Division of Nephrology, Children's National Health System, The George Washington University School of Medicine, Washington, DC
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9
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Sphingosylphosphorylcholine inhibits macrophage adhesion to vascular smooth muscle cells. Biochem Pharmacol 2016; 115:43-50. [PMID: 27402344 PMCID: PMC4981491 DOI: 10.1016/j.bcp.2016.07.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 07/06/2016] [Indexed: 12/16/2022]
Abstract
Inflammation in de-endothelialised arteries contributes to the development of cardiovascular diseases. The process that initiates this inflammatory response is the adhesion of monocytes/macrophages to exposed vascular smooth muscle cells, typically stimulated by cytokines such as tumour necrosis factor-α (TNF). The aim of this study was to determine the effect of the sphingolipid sphingosylphosphorylcholine (SPC) on the interaction of monocytes/macrophages with vascular smooth muscle cells. Rat aortic smooth muscle cells and rat bone marrow-derived macrophages were co-cultured using an in vitro assay following incubation with sphingolipids to assess inter-cellular adhesion. We reveal that SPC inhibits the TNF-induced adhesion of macrophages to smooth muscle cells. This anti-adhesive effect was the result of SPC-induced changes to the smooth muscle cells (but not the macrophages) and was mediated, at least partly, via the sphingosine 1-phosphate receptor subtype 2. Lipid raft domains were also required. Although SPC did not alter expression or membrane distribution of the adhesion proteins intercellular adhesion molecule-1 and vascular cellular adhesion protein-1 in smooth muscle cells, SPC preincubation inhibited the TNF-induced increase in inducible nitric oxide synthase (NOS2) resulting in a subsequent decrease in nitric oxide production. Inhibiting NOS2 activation in smooth muscle cells led to a decrease in the adhesion of macrophages to smooth muscle cells. This study has therefore delineated a novel pathway which can inhibit the interaction between macrophages and vascular smooth muscle cells via SPC-induced repression of NOS2 expression. This mechanism could represent a potential drug target in vascular disease.
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10
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Chen Y, Yuan M, Xia M, Wang L, Zhang Y, Li PL. Instant membrane resealing in nlrp3 inflammmasome activation of endothelial cells. Front Biosci (Landmark Ed) 2016; 21:635-50. [PMID: 26709796 DOI: 10.2741/4411] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The present study explored the molecular mechanisms by which instant cell membrane resealing (CMR) controls the activation of NOD-like receptor pyrin domain containing 3 (Nlrp3) inflammasomes. Using wavelength-switching fluorescent microscopy with PI and fura-2 as indicators, we monitored instant CMR simultaneously with (Ca(2+))i in mouse microvascular endothelial cell (MVECs). LCWE or saponin wad found to produce membrane injury, which was resealed in a Ca(2+)-dependent manner, but abolished by FasL, a membrane raft (MR) clustering stimulator. Even in the presence of Ca(2+), FasL prolonged the CMR time as shown by an earlier onset of PI influx (48±12 sec vs. 17±3 min. of control). These effects of FasL were substantially blocked by an MR disruptor, methyl-beta-cyclodextrin (MCD). The failure of CMR upon FasL activated Nlrp3 inflammasomes, which was blocked by MCD, a membrane resealing compound, VA64 or siRNA of an MR-facilitating enzyme, acid sphingomyelinase. This inflammasome activation was due to increased lysosomal permeability and cathepsin B release. It is concluded that an MR-associated CMR protects ECs from Nlrp3 inflammasome activation induced by membrane injury.
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Affiliation(s)
- Yang Chen
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, 1220 East Broad Street, Richmond, VA 23298, 2Department of Pharmacological & Pharmaceutical Sciences College of Pharmacy, University of Houston, 3605 Cullen B
| | | | | | - Lei Wang
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University
| | - Yang Zhang
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204
| | - Pin-Lan Li
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, 1220 East Broad Street, Richmond, VA 23298, 2Department of Pharmacological & Pharmaceutical Sciences College of Pharmacy, University of Houston, 3605 Cullen B,
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11
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Sanon VP, Sawaki D, Mjaatvedt CH, Jourdan‐Le Saux C. Myocardial Tissue Caveolae. Compr Physiol 2015; 5:871-86. [DOI: 10.1002/cphy.c140050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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12
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Chen H, Leng Y, Li Z. β-actin in the signaling of transmembrane TNF-α-mediated cytotoxicity. Methods Mol Biol 2014; 1155:55-68. [PMID: 24788173 DOI: 10.1007/978-1-4939-0669-7_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
To study the role of β-actin in the signaling of transmembrane TNF-α (tmTNF-α)-mediated cytotoxicity, we mainly used bioassay and apoptosis assay, detection of the visual changes in β-actin and intracellular translocation of signal molecules in response to tmTNF-α, and analysis of the signal molecules coupled or uncoupled with TNFR2 complex. These protocols might also be used to investigate the signaling events mediated by other transmembrane cytokines or members of TNF superfamily, which have transmembrane and soluble forms, as well as the involvement of actin cytoskeleton in signal transduction pathways.
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Affiliation(s)
- Hui Chen
- Department of Immunology, Medical College, Wuhan University of Science and Technology, Wuhan, Hubei, PR China
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13
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Voss M, Schröder B, Fluhrer R. Mechanism, specificity, and physiology of signal peptide peptidase (SPP) and SPP-like proteases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2828-39. [PMID: 24099004 DOI: 10.1016/j.bbamem.2013.03.033] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 03/25/2013] [Accepted: 03/29/2013] [Indexed: 01/09/2023]
Abstract
Signal peptide peptidase (SPP) and the homologous SPP-like (SPPL) proteases SPPL2a, SPPL2b, SPPL2c and SPPL3 belong to the family of GxGD intramembrane proteases. SPP/SPPLs selectively cleave transmembrane domains in type II orientation and do not require additional co-factors for proteolytic activity. Orthologues of SPP and SPPLs have been identified in other vertebrates, plants, and eukaryotes. In line with their diverse subcellular localisations ranging from the ER (SPP, SPPL2c), the Golgi (SPPL3), the plasma membrane (SPPL2b) to lysosomes/late endosomes (SPPL2a), the different members of the SPP/SPPL family seem to exhibit distinct functions. Here, we review the substrates of these proteases identified to date as well as the current state of knowledge about the physiological implications of these proteolytic events as deduced from in vivo studies. Furthermore, the present knowledge on the structure of intramembrane proteases of the SPP/SPPL family, their cleavage mechanism and their substrate requirements are summarised. This article is part of a Special Issue entitled: Intramembrane Proteases.
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Affiliation(s)
- Matthias Voss
- Adolf Butenandt Institute for Biochemistry, Ludwig-Maximilians University Munich, Schillerstr. 44, 80336 Munich, Germany
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14
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Entry of human rhinovirus 89 via ICAM-1 into HeLa epithelial cells is inhibited by actin skeleton disruption and by bafilomycin. Arch Virol 2013; 159:125-40. [DOI: 10.1007/s00705-013-1797-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 06/03/2013] [Indexed: 01/11/2023]
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15
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Palmitoylation of TNF alpha is involved in the regulation of TNF receptor 1 signalling. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:602-12. [DOI: 10.1016/j.bbamcr.2012.11.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 11/05/2012] [Accepted: 11/08/2012] [Indexed: 12/27/2022]
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16
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Abstract
Membrane rafts (MRs) are specialized microdomains in the cell membrane with an altered lipid composition. Upon various stimulations, MRs can be clustered to aggregate or recruit NADPH oxidase sub-units and related proteins to form MR redox signalosomes in the membrane of cells like vascular endothelial cells (ECs). Multiple protein complexes, like MR redox signalosomes, are now considered to play a crucial role in the regulation of cell function and in the development of different cell dysfunctions. To form such redox signalosomes, ceramide will be generated from the hydrolysis of sphingomyelin by lysosomal acid sphingomyelinase that has been translocated via lysosome fusion to the MR area. In this brief review, current information is provided to help understand the occurrence and function of MR redox signalosomes. This may increase enthusiasm of the scientific community for further studies on the molecular mechanisms and the functional significance of forming such MR redox signalosomes.
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Affiliation(s)
- Chun Zhang
- Department of Pharmacology & Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA 23298, USA
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Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) encodes two RING finger E3 ubiquitin ligases (MIR1 and MIR2) that mediate ubiquitination and degradation of cellular proteins important for the establishment of an efficient antiviral immune response. MIR1 and MIR2 share 30% sequence identity; however, their substrate preferences are varied. MIR1 has been shown to primarily downregulate major histocompatibility complex class I (MHC-I), whereas MIR2 can downregulate a wide range of cell surface proteins. Many of the MIR substrates are thought to be present in lipid raft microdomains, a subregion of the plasma membrane known to be important for a wide range of signal transduction events. Palmitoylation is a posttranslational modification that increases recruitment of transmembrane proteins to lipid rafts. In this study, we investigated the importance of palmitoylation for MIR function. We present evidence that MIR2-mediated downregulation of MHC-I and platelet endothelial cell adhesion molecule 1 (PECAM-1) but not other substrates is inhibited in the presence of the drug 2-bromohexadecanoic acid (2-Br), a chemical inhibitor of palmitoylation. Biochemical analysis indicates that MIR2 is directly palmitoylated on cysteine 146. Mutation of this cysteine to a phenylalanine prevents MIR2 palmitoylation and blocks the ability of MIR2 to downregulate MHC-I and PECAM-I but not B7.2 and intercellular adhesion molecule 1 (ICAM-I), consistent with the phenotype observed after 2-Br treatment. Unpalmitoylated MIR2 does not interact with MHC-I and is thus unable to ubiquitinate and downregulate MHC-I from the cell surface. Furthermore, we observed that MIR2 is palmitoylated in vivo during lytic infection. Palmitoylation may act to regulate MIR2 function and localization during viral infection by allowing MIR2 to properly interact with and downregulate multiple substrates known to play an important role in the host immune response.
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Horiuchi T, Mitoma H, Harashima SI, Tsukamoto H, Shimoda T. Transmembrane TNF-alpha: structure, function and interaction with anti-TNF agents. Rheumatology (Oxford) 2010; 49:1215-28. [PMID: 20194223 PMCID: PMC2886310 DOI: 10.1093/rheumatology/keq031] [Citation(s) in RCA: 557] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Transmembrane TNF-α, a precursor of the soluble form of TNF-α, is expressed on activated macrophages and lymphocytes as well as other cell types. After processing by TNF-α-converting enzyme (TACE), the soluble form of TNF-α is cleaved from transmembrane TNF-α and mediates its biological activities through binding to Types 1 and 2 TNF receptors (TNF-R1 and -R2) of remote tissues. Accumulating evidence suggests that not only soluble TNF-α, but also transmembrane TNF-α is involved in the inflammatory response. Transmembrane TNF-α acts as a bipolar molecule that transmits signals both as a ligand and as a receptor in a cell-to-cell contact fashion. Transmembrane TNF-α on TNF-α-producing cells binds to TNF-R1 and -R2, and transmits signals to the target cells as a ligand, whereas transmembrane TNF-α also acts as a receptor that transmits outside-to-inside (reverse) signals back to the cells after binding to its native receptors. Anti-TNF agents infliximab, adalimumab and etanercept bind to and neutralize soluble TNF-α, but exert different effects on transmembrane TNF-α-expressing cells (TNF-α-producing cells). In the clinical settings, these three anti-TNF agents are equally effective for RA, but etanercept is not effective for granulomatous diseases. Moreover, infliximab induces granulomatous infections more frequently than etanercept. Considering the important role of transmembrane TNF-α in granulomatous inflammation, reviewing the biology of transmembrane TNF-α and its interaction with anti-TNF agents will contribute to understanding the bases of differential clinical efficacy of these promising treatment modalities.
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Affiliation(s)
- Takahiko Horiuchi
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
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Current Opinion in Clinical Nutrition and Metabolic Care. Current world literature. Curr Opin Clin Nutr Metab Care 2010; 13:215-21. [PMID: 20145440 DOI: 10.1097/mco.0b013e32833643b4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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