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Molecular characterization and expression profiling of caveolin-1 from Amphiprion clarkii and elucidation of its involvement in antiviral response and redox homeostasis. Comp Biochem Physiol B Biochem Mol Biol 2022; 262:110775. [DOI: 10.1016/j.cbpb.2022.110775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 06/07/2022] [Accepted: 06/24/2022] [Indexed: 11/20/2022]
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Torices S, Roberts SA, Park M, Malhotra A, Toborek M. Occludin, caveolin-1, and Alix form a multi-protein complex and regulate HIV-1 infection of brain pericytes. FASEB J 2020; 34:16319-16332. [PMID: 33058236 PMCID: PMC7686148 DOI: 10.1096/fj.202001562r] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/18/2020] [Accepted: 10/02/2020] [Indexed: 12/24/2022]
Abstract
HIV-1 enters the brain by altering properties of the blood-brain barrier (BBB). Recent evidence indicates that among cells of the BBB, pericytes are prone to HIV-1 infection. Occludin (ocln) and caveolin-1 (cav-1) are critical determinants of BBB integrity that can regulate barrier properties of the BBB in response to HIV-1 infection. Additionally, Alix is an early acting endosomal factor involved in HIV-1 budding from the cells. The aim of the present study was to evaluate the role of cav-1, ocln, and Alix in HIV-1 infection of brain pericytes. Our results indicated that cav-1, ocln, and Alix form a multi-protein complex in which they cross-regulate each other's expression. Importantly, the stability of this complex was affected by HIV-1 infection. Modifications of the complex resulted in diminished HIV-1 infection and alterations of the cytokine profile produced by brain pericytes. These results identify a novel mechanism involved in HIV-1 infection contributing to a better understanding of the HIV-1 pathology and the associated neuroinflammatory responses.
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Affiliation(s)
- Silvia Torices
- Department of Biochemistry and Molecular BiologyUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Samantha A. Roberts
- Department of Biochemistry and Molecular BiologyUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Minseon Park
- Department of Biochemistry and Molecular BiologyUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Arun Malhotra
- Department of Biochemistry and Molecular BiologyUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Michal Toborek
- Department of Biochemistry and Molecular BiologyUniversity of Miami Miller School of MedicineMiamiFLUSA
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Sahay B, Mergia A. The Potential Contribution of Caveolin 1 to HIV Latent Infection. Pathogens 2020; 9:pathogens9110896. [PMID: 33121153 PMCID: PMC7692328 DOI: 10.3390/pathogens9110896] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/25/2022] Open
Abstract
Combinatorial antiretroviral therapy (cART) suppresses HIV replication to undetectable levels and has been effective in prolonging the lives of HIV infected individuals. However, cART is not capable of eradicating HIV from infected individuals mainly due to HIV’s persistence in small reservoirs of latently infected resting cells. Latent infection occurs when the HIV-1 provirus becomes transcriptionally inactive and several mechanisms that contribute to the silencing of HIV transcription have been described. Despite these advances, latent infection remains a major hurdle to cure HIV infected individuals. Therefore, there is a need for more understanding of novel mechanisms that are associated with latent infection to purge HIV from infected individuals thoroughly. Caveolin 1(Cav-1) is a multifaceted functional protein expressed in many cell types. The expression of Cav-1 in lymphocytes has been controversial. Recent evidence, however, convincingly established the expression of Cav-1 in lymphocytes. In lieu of this finding, the current review examines the potential role of Cav-1 in HIV latent infection and provides a perspective that helps uncover new insights to understand HIV latent infection.
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Affiliation(s)
| | - Ayalew Mergia
- Correspondence: ; Tel.: +352-294-4139; Fax: +352-392-9704
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Multifaceted Functions of Host Cell Caveolae/Caveolin-1 in Virus Infections. Viruses 2020; 12:v12050487. [PMID: 32357558 PMCID: PMC7291293 DOI: 10.3390/v12050487] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 02/07/2023] Open
Abstract
Virus infection has drawn extensive attention since it causes serious or even deadly diseases, consequently inducing a series of social and public health problems. Caveolin-1 is the most important structural protein of caveolae, a membrane invagination widely known for its role in endocytosis and subsequent cytoplasmic transportation. Caveolae/caveolin-1 is tightly associated with a wide range of biological processes, including cholesterol homeostasis, cell mechano-sensing, tumorigenesis, and signal transduction. Intriguingly, the versatile roles of caveolae/caveolin-1 in virus infections have increasingly been appreciated. Over the past few decades, more and more viruses have been identified to invade host cells via caveolae-mediated endocytosis, although other known pathways have been explored. The subsequent post-entry events, including trafficking, replication, assembly, and egress of a large number of viruses, are caveolae/caveolin-1-dependent. Deprivation of caveolae/caveolin-1 by drug application or gene editing leads to abnormalities in viral uptake, viral protein expression, or virion release, whereas the underlying mechanisms remain elusive and must be explored holistically to provide potential novel antiviral targets and strategies. This review recapitulates our current knowledge on how caveolae/caveolin-1 functions in every step of the viral infection cycle and various relevant signaling pathways, hoping to provide a new perspective for future viral cell biology research.
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Díez-Fuertes F, De La Torre-Tarazona HE, Calonge E, Pernas M, Bermejo M, García-Pérez J, Álvarez A, Capa L, García-García F, Saumoy M, Riera M, Boland-Auge A, López-Galíndez C, Lathrop M, Dopazo J, Sakuntabhai A, Alcamí J. Association of a single nucleotide polymorphism in the ubxn6 gene with long-term non-progression phenotype in HIV-positive individuals. Clin Microbiol Infect 2019; 26:107-114. [PMID: 31158522 DOI: 10.1016/j.cmi.2019.05.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 05/07/2019] [Accepted: 05/19/2019] [Indexed: 11/17/2022]
Abstract
OBJECTIVES The long-term non-progressors (LTNPs) are a heterogeneous group of HIV-positive individuals characterized by their ability to maintain high CD4+ T-cell counts and partially control viral replication for years in the absence of antiretroviral therapy. The present study aims to identify host single nucleotide polymorphisms (SNPs) associated with non-progression in a cohort of 352 individuals. METHODS DNA microarrays and exome sequencing were used for genotyping about 240 000 functional polymorphisms throughout more than 20 000 human genes. The allele frequencies of 85 LTNPs were compared with a control population. SNPs associated with LTNPs were confirmed in a population of typical progressors. Functional analyses in the affected gene were carried out through knockdown experiments in HeLa-P4, macrophages and dendritic cells. RESULTS Several SNPs located within the major histocompatibility complex region previously related to LTNPs were confirmed in this new cohort. The SNP rs1127888 (UBXN6) surpassed the statistical significance of these markers after Bonferroni correction (q = 2.11 × 10-6). An uncommon allelic frequency of rs1127888 among LTNPs was confirmed by comparison with typical progressors and other publicly available populations. UBXN6 knockdown experiments caused an increase in CAV1 expression and its accumulation in the plasma membrane. In vitro infection of different cell types with HIV-1 replication-competent recombinant viruses caused a reduction of the viral replication capacity compared with their corresponding wild-type cells expressing UBXN6. CONCLUSIONS A higher prevalence of Ala31Thr in UBXN6 was found among LTNPs within its N-terminal region, which is crucial for UBXN6/VCP protein complex formation. UBXN6 knockdown affected CAV1 turnover and HIV-1 replication capacity.
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Affiliation(s)
- F Díez-Fuertes
- AIDS Immunopathology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain; Hospital Clínic- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
| | - H E De La Torre-Tarazona
- AIDS Immunopathology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - E Calonge
- AIDS Immunopathology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - M Pernas
- Molecular Virology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - M Bermejo
- AIDS Immunopathology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - J García-Pérez
- AIDS Immunopathology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - A Álvarez
- AIDS Immunopathology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - L Capa
- AIDS Immunopathology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - F García-García
- Unidad de Bioinformática y Bioestadística, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
| | - M Saumoy
- HIV Unit, Infectious Disease Service, Hospital Universitari de Bellvitge, Barcelona, Spain
| | - M Riera
- Servicio de Medicina Interna-Infecciosas, Hospital Universitario "Son Espases", Palma de Mallorca, Spain
| | - A Boland-Auge
- Centre National de Recherche en Génomique Humaine (CNRGH), Institut de Biologie François Jacob, CEA, Université Paris-Saclay, Evry, France
| | - C López-Galíndez
- Molecular Virology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - M Lathrop
- Centre National de Recherche en Génomique Humaine (CNRGH), Institut de Biologie François Jacob, CEA, Université Paris-Saclay, Evry, France
| | - J Dopazo
- Clinical Bioinformatics Area, Fundación Progreso y Salud (FPS), CDCA, Hospital Virgen del Rocio, Sevilla, Spain; Bioinformatics in Rare Diseases (BiER), Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), FPS, Hospital Virgen del Rocío, Sevilla, Spain; INB-ELIXIR-es, FPS, Hospital Virgen del Rocío, Sevilla, Spain
| | - A Sakuntabhai
- Functional Genetics of Infectious Diseases, Pasteur Institute, Paris, France
| | - J Alcamí
- AIDS Immunopathology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain; Hospital Clínic- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
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Role of Cav-1 in HIV-1 Tat-Induced Dysfunction of Tight Junctions and A β-Transferring Proteins. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:3403206. [PMID: 31217837 PMCID: PMC6537002 DOI: 10.1155/2019/3403206] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 04/04/2019] [Indexed: 12/14/2022]
Abstract
Objective To evaluate the role of caveolin-1 (Cav-1) in HIV-1 Tat-induced dysfunction of tight junction and amyloid β-peptide- (Aβ-) transferring proteins. Methods A Cav-1 shRNA interference target sequence was cloned into the lentiviral vector pHBLV-U6-Scramble-ZsGreen-Puro and verified by double enzyme digestion and DNA sequencing. Human cerebral microvascular endothelium (HBEC-5i) cells were transduced with viral particles made in 293T cells by transfection with lentiviral packaging plasmids. HBEC-5i cells transduced with Cav-1 shRNA or Ctr shRNA were exposed to HIV-1 Tat for 24 h, and the protein and mRNA levels of the tight junction protein occludin, Aβ-transferring protein, receptor for advanced glycation end products (RAGE), low-density lipoprotein receptor-related protein- (LRP-) 1, and RhoA were evaluated with Western blot and real-time reverse transcription polymerase chain reaction (qRT-PCR) assays, respectively. Results After sequencing, an RNA interference recombinant lentivirus expressing a vector targeting Cav-1 was successfully established. The recombined lentiviral particles were made by using 293T cells to package the recombined lentiviral vector. A stable monoclonal cell line with strong GFP expression was acquired with a Cav-1 knockdown rate of 85.7%. The occludin protein and mRNA levels in the Ctr shRNA group were decreased with HIV-1 Tat exposure but were upregulated in the Cav-1 shRNA group. The HIV-1 Tat-induced alterations of RAGE and LRP-1 protein and mRNA levels in the Ctr shRNA group were attenuated in the Cav-1 shRNA group. The RhoA protein levels in the Ctr shRNA group were upregulated by HIV-1 Tat exposure but were downregulated in the Cav-1 shRNA group. Conclusion These results show that HIV-1 Tat-induced downregulation of occludin and LRP-1 and upregulation of RAGE and RhoA may result in the accumulation of Aβ in the brain. Silencing the Cav-1 gene with shRNA plays a key role in the protection against HIV-1 Tat-induced dysfunction of the blood-brain barrier and Aβ accumulation.
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Multiple Inhibitory Factors Act in the Late Phase of HIV-1 Replication: a Systematic Review of the Literature. Microbiol Mol Biol Rev 2018; 82:82/1/e00051-17. [PMID: 29321222 DOI: 10.1128/mmbr.00051-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The use of lentiviral vectors for therapeutic purposes has shown promising results in clinical trials. The ability to produce a clinical-grade vector at high yields remains a critical issue. One possible obstacle could be cellular factors known to inhibit human immunodeficiency virus (HIV). To date, five HIV restriction factors have been identified, although it is likely that more factors are involved in the complex HIV-cell interaction. Inhibitory factors that have an adverse effect but do not abolish virus production are much less well described. Therefore, a gap exists in the knowledge of inhibitory factors acting late in the HIV life cycle (from transcription to infection of a new cell), which are relevant to the lentiviral vector production process. The objective was to review the HIV literature to identify cellular factors previously implicated as inhibitors of the late stages of lentivirus production. A search for publications was conducted on MEDLINE via the PubMed interface, using the keyword sequence "HIV restriction factor" or "HIV restriction" or "inhibit HIV" or "repress HIV" or "restrict HIV" or "suppress HIV" or "block HIV," with a publication date up to 31 December 2016. Cited papers from the identified records were investigated, and additional database searches were performed. A total of 260 candidate inhibitory factors were identified. These factors have been identified in the literature as having a negative impact on HIV replication. This study identified hundreds of candidate inhibitory factors for which the impact of modulating their expression in lentiviral vector production could be beneficial.
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Udayantha HMV, Bathige SDNK, Priyathilaka TT, Lee S, Kim MJ, Lee J. Identification and characterization of molluscan caveolin-1 ortholog from Haliotis discus discus: Possible involvement in embryogenesis and host defense mechanism against pathogenic stress. Gene Expr Patterns 2017; 27:85-92. [PMID: 29128397 DOI: 10.1016/j.gep.2017.11.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 06/13/2017] [Accepted: 11/06/2017] [Indexed: 02/05/2023]
Abstract
Caveolins are principal membrane proteins of caveolae that play a central role in signal transduction, substrate transport, and membrane trafficking in various cell types. Numerous studies have reported the crucial role of caveolin-1 (CAV1) in response to invading microbes; yet, very little is known about molluscan CAV1. In this study, we identified and characterized CAV1 ortholog from the disk abalone, Haliotis discus discus (HdCAV1). The cDNA sequence of HdCAV1 is 826 bp long and encodes a 127-amino acid polypeptide. Characteristic caveolin superfamily domain (Glu3 - Lys126) and two possible transmembrane domains (Cys48 - Tyr67 and Ile103 - Phe120) were identified in the HdCAV1 protein. Homology analysis revealed that HdCAV1 shared higher identity (>47%) with molluscans, but lower identity with other species. Phylogenetic tree constructed by the neighbor-joining (NJ) method revealed a distinct evolutionary pathway for molluscans. Transcriptional analysis by SYBR Green qPCR showed the highest expression of HdCAV1 mRNA in late veliger stage, as compared to that in other embryonic developmental stages of disk abalone. In adult animals, gill tissue showed highest HdCAV1 transcript levels under normal physiological condition. Stimulations with two bacteria (Vibrio parahaemolyticus and Listeria monocytogenes), viral hemorrhagic septicemia virus, and two pathogen-associated molecular patterns (LPS and poly I:C) significantly modulated the expression of HdCAV1 transcripts. Collectively, these data suggest that CAV1 plays an important role in embryogenesis and host immune defense in disk abalone.
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Affiliation(s)
- H M V Udayantha
- Department of Marine Life Sciences, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea; Department of Fisheries and Aquaculture, Faculty of Fisheries and Marine Sciences and Technology, University of Ruhuna, Matara, Sri Lanka
| | - S D N K Bathige
- Department of Marine Life Sciences, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea; Sri Lanka Institute of Nanotechnology (SLINTEC), Nanotechnology and Science Park, Mahenwatta, Pitipana, Homagama, Sri Lanka
| | - Thanthrige Thiunuwan Priyathilaka
- Department of Marine Life Sciences, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea; Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea
| | - Sukkyoung Lee
- Department of Marine Life Sciences, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea; Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea
| | - Myoung-Jin Kim
- Department of Marine Life Sciences, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea; Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea.
| | - Jehee Lee
- Department of Marine Life Sciences, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea; Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea.
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The Role of Caveolin 1 in HIV Infection and Pathogenesis. Viruses 2017; 9:v9060129. [PMID: 28587148 PMCID: PMC5490806 DOI: 10.3390/v9060129] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 05/02/2017] [Accepted: 05/22/2017] [Indexed: 12/29/2022] Open
Abstract
Caveolin 1 (Cav-1) is a major component of the caveolae structure and is expressed in a variety of cell types including macrophages, which are susceptible to human immunodeficiency virus (HIV) infection. Caveolae structures are present in abundance in mechanically stressed cells such as endothelial cells and adipocytes. HIV infection induces dysfunction of these cells and promotes pathogenesis. Cav-1 and the caveolae structure are believed to be involved in multiple cellular processes that include signal transduction, lipid regulation, endocytosis, transcytosis, and mechanoprotection. Such a broad biological role of Cav-1/caveolae is bound to have functional cross relationships with several molecular pathways including HIV replication and viral-induced pathogenesis. The current review covers the relationship of Cav-1 and HIV in respect to viral replication, persistence, and the potential role in pathogenesis.
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Removal of ribonucleotides by p53 protein incorporated during DNA synthesis by HIV-1 reverse transcriptase. AIDS 2017; 31:343-353. [PMID: 28081035 DOI: 10.1097/qad.0000000000001339] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE(S) HIV-1 reverse transcriptase frequently incorporates ribonucleotides into the proviral DNA in macrophages, but not in lymphocytes. The enzyme exerts an efficient ribonucleotide-terminated primer extension capacity. Furthermore, ribonucleotide-editing repair is attenuated in macrophages. Tumor suppressor p53 protein, displaying an intrinsic 3'→5' exonuclease activity, was found to be involved in efficient proofreading of base-base mismatches produced during DNA synthesis. As the presence of proofreading activity is cardinal for the DNA synthesis accuracy, it was of interest to assess whether p53 can serve as a trans-acting proofreader for HIV-1 reverse transcriptase during ribonucleotide incorporation. DESIGN We investigated the potential involvement of cytoplasmic p53 in error correction during insertion of ribonucleotides into DNA by recombinant HIV-1 reverse transcriptase in a p53-proficient and deficient background. METHODS Primer extension reactions were carried out to elucidate the incorporation and removal of ribonucleotides. RESULTS The biochemical studies suggest that p53 is involved in a ribonucleotide damage-associated repair mechanism through its capacity to remove preformed 3'-terminal ribonucleotides, to decrease ribonucleotide incorporation and to prevent the 3'-ribo-terminated primer extension during ongoing DNA synthesis by HIV-1 reverse transcriptase. A positive correlation exists between the presence of endogenous p53 and decrease in stable incorporation of ribonucleotides into DNA with p53-harboring lysates of HCT116 cells. p53, by preferential removal of purine over pyrimidine ribonucleotides, may affect the ribonucleotide mutation spectra produced by HIV-1 reverse transcriptase. CONCLUSION The data implies that p53 can excise incorrect sugar in addition to base mispairs, thereby expanding the role of p53 in the repair of nucleic acids replication errors.
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Ahn SH, Cho SH, Song JE, Kim S, Oh SS, Jung S, Cho KA, Lee TH. Caveolin-1 serves as a negative effector in senescent human gingival fibroblasts during Fusobacterium nucleatum infection. Mol Oral Microbiol 2016; 32:236-249. [PMID: 27315395 DOI: 10.1111/omi.12167] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2016] [Indexed: 12/11/2022]
Abstract
It is well established that aging is associated with increased susceptibility to infectious diseases. Fusobacterium nucleatum is a well-known bacterial species that plays a central bridging role between early and late colonizers in the human oral cavity. Further, the ability of F. nucleatum to invade gingival fibroblasts (GFs) is critical to the development of periodontal diseases. However, the mechanisms underlying the age-related infection of GFs by F. nucleatum remain unknown. We used young (fourth passage) and senescent (22nd passage) GFs to investigate the mechanisms of F. nucleatum infection in aged GFs and first observed increased invasion of F. nucleatum in senescent GFs. We also found that the co-localization of caveolin-1 (Cav-1), a protein marker of aging, with F. nucleatum and the knockdown of Cav-1 in GFs reduced F. nucleatum invasion. Additionally, F. nucleatum infection triggered the production of reactive oxygen species (ROS) through activation of NADPH oxidase in GFs, but senescent GFs exhibited significantly lower levels of NADPH oxidase activity and ROS production compared with young GFs in both the uninfected and infected conditions. Also, senescent GFs exhibited a decline in proinflammatory cytokine production and extracellular signal regulated kinase (ERK) phosphorylation following F. nucleatum infection. Interestingly, the knockdown of Cav-1 in senescent GFs increased NADPH oxidase activity and caused the upregulation of interleukin-6 and interleukin-8 and the phosphorylation of ERK. Collectively, the increased expression of Cav-1 might play a critical role in F. nucleatum invasion and could hinder the host response in senescent GFs.
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Affiliation(s)
- S H Ahn
- Department of Oral Biochemistry, Dental Science Research Institute, Medical Research Center for Biomineralization Disorders, School of Dentistry, Chonnam National University, Gwangju, Korea
| | - S-H Cho
- Department of Molecular Medicine (BK21plus), Chonnam National University Graduate School, Gwangju, Korea
| | - J-E Song
- Department of Molecular Medicine (BK21plus), Chonnam National University Graduate School, Gwangju, Korea
| | - S Kim
- Department of Oral Biochemistry, Dental Science Research Institute, Medical Research Center for Biomineralization Disorders, School of Dentistry, Chonnam National University, Gwangju, Korea.,Department of Molecular Medicine (BK21plus), Chonnam National University Graduate School, Gwangju, Korea
| | - S S Oh
- Department of Oral Biochemistry, Dental Science Research Institute, Medical Research Center for Biomineralization Disorders, School of Dentistry, Chonnam National University, Gwangju, Korea
| | - S Jung
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Chonnam National University, Gwangju, Korea
| | - K A Cho
- Department of Biochemistry, Chonnam National University Medical School, Gwangju, Korea
| | - T-H Lee
- Department of Oral Biochemistry, Dental Science Research Institute, Medical Research Center for Biomineralization Disorders, School of Dentistry, Chonnam National University, Gwangju, Korea.,Department of Molecular Medicine (BK21plus), Chonnam National University Graduate School, Gwangju, Korea
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Selvan LDN, Sreenivasamurthy SK, Kumar S, Yelamanchi SD, Madugundu AK, Anil AK, Renuse S, Nair BG, Gowda H, Mathur PP, Satishchandra P, Shankar SK, Mahadevan A, Keshava Prasad TS. Characterization of host response to Cryptococcus neoformans through quantitative proteomic analysis of cryptococcal meningitis co-infected with HIV. MOLECULAR BIOSYSTEMS 2016; 11:2529-40. [PMID: 26181685 DOI: 10.1039/c5mb00187k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Cryptococcal meningitis is the most common opportunistic fungal infection causing morbidity and mortality (>60%) in HIV-associated immunocompromised individuals caused by Cryptococcus neoformans. Molecular mechanisms of cryptococcal infection in brain have been studied using experimental animal models and cell lines. There are limited studies for the molecular understanding of cryptococcal meningitis in human brain. The proteins involved in the process of invasion and infection in human brain still remains obscure. To this end we carried out mass spectrometry-based quantitative proteomics of frontal lobe brain tissues from cryptococcal meningitis patients and controls to identify host proteins that are associated with the pathogenesis of cryptococcal meningitis. We identified 317 proteins to be differentially expressed (≥2-fold) from a total of 3423 human proteins. We found proteins involved in immune response and signal transduction to be differentially expressed in response to cryptococcal infection in human brain. Immune response proteins including complement factors, major histocompatibility proteins, proteins previously known to be involved in fungal invasion to brain such as caveolin 1 and actin were identified to be differentially expressed in cryptococcal meningitis brain tissues co-infected with HIV. We also validated the expression status of 5 proteins using immunohistochemistry. Overexpression of major histocompatibility complexes, class I, B (HLA-B), actin alpha 2 smooth muscle aorta (ACTA2) and caveolin 1 (CAV1) and downregulation of peripheral myelin protein 2 (PMP2) and alpha crystallin B chain (CRYAB) in cryptococcal meningitis were confirmed by IHC-based validation experiments. This study provides the brain proteome profile of cryptococcal meningitis co-infected with HIV for a better understanding of the host response associated with the disease.
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Lin S, Nadeau PE, Mergia A. HIV inhibits endothelial reverse cholesterol transport through impacting subcellular Caveolin-1 trafficking. Retrovirology 2015; 12:62. [PMID: 26169283 PMCID: PMC4501058 DOI: 10.1186/s12977-015-0188-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 07/06/2015] [Indexed: 01/13/2023] Open
Abstract
Background Human immunodeficiency virus (HIV) infection leads to decreased reverse cholesterol transport (RCT) in macrophages, and Nef mediated down-regulation and redistribution of ATP-binding cassette transporter A1 (ABCA1) are identified as key factors for this effect. This may partially explain the increased risk of atherosclerosis in HIV infected individuals. Since endothelial dysfunction is key in the initial stages of atherosclerosis, we sought to determine whether RCT was affected in human aortic endothelial cells (HAECs). Results We found that apoA-I does not significantly stimulate cholesterol efflux in HAECs while cholesterol efflux to high-density lipoprotein (HDL) was dramatically reduced in HAECs co-cultured with HIV infected cells. Studies with wild type and Nef defective HIV revealed no significant differences suggesting that multiple factors are working perhaps in concert with Nef to affect cholesterol efflux to HDL from HAECs. Interestingly, treating HAECs with recombinant Nef showed similar effect in HDL mediated cholesterol efflux as observed in HAECs co-cultured with HIV infected cells. Using a detergent-free based subcellular fractionation approach, we demonstrated that exposure of HAECs to HIV infected cells or Nef alone disrupts caveolin 1 (Cav-1) subcellular trafficking upon HDL stimulation. Moreover, Nef significantly enhanced tyrosine 14 phosphorylation of Cav-1 which may have an impact on recycling of Cav-1 and caveolae. Conclusion These results suggest that HIV interferes with cholesterol efflux by HDL in HAECs through the disruption of Cav-1s’ cellular distribution and that multiple factors are involved, possibly including Nef, for the inhibition of HDL mediated cholesterol efflux and alteration of cellular distribution of Cav-1. Electronic supplementary material The online version of this article (doi:10.1186/s12977-015-0188-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shanshan Lin
- Department of Infectious Diseases and Pathology, University of Florida, Gainesville, FL, 32611, USA.
| | - Peter E Nadeau
- Department of Infectious Diseases and Pathology, University of Florida, Gainesville, FL, 32611, USA.
| | - Ayalew Mergia
- Department of Infectious Diseases and Pathology, University of Florida, Gainesville, FL, 32611, USA.
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Dhamija N, Choudhary D, Ladha JS, Pillai B, Mitra D. Tat predominantly associates with host promoter elements in HIV-1-infected T-cells - regulatory basis of transcriptional repression of c-Rel. FEBS J 2014; 282:595-610. [PMID: 25472883 DOI: 10.1111/febs.13168] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 11/19/2014] [Accepted: 12/02/2014] [Indexed: 11/28/2022]
Abstract
HIV-1 Tat is a multifunctional regulatory protein that, in addition to its primary function of transactivating viral transcription, also tends to modulate cellular gene expression, for which the molecular mechanism remains to be clarified. We have reported earlier nuclear factor kappa B (NFκB) enhancer binding activity of Tat and proposed this DNA binding activity as a possible molecular basis for Tat-mediated regulation of cellular gene expression in infected cells. In the present study, we analyzed the genome-wide occupancy of Tat protein on host cell chromatin in HIV-1-infected T-cells to investigate a potential role of Tat on cellular gene expression. The results obtained identify a spectrum of binding sites of Tat protein on the chromatin and reveal that Tat is also recruited on a number of cellular gene promoters in HIV-1-infected T-cells, indicating its possible involvement in the regulation of gene expression of such cellular genes. Tat was identified as a repressor of one such validated gene, c-Rel, because it downregulates the expression of c-Rel in both Tat expressing and HIV-1-infected T-cells. The results also show that Tat downregulates c-Rel promoter activity by interacting with specific NFκB sites on the c-Rel promoter, thus providing a molecular basis of Tat-mediated regulation of cellular gene expression. Thus, in the present study, we have not only identified recruitment sites of Tat on the chromatin in HIV-1-infected T-cells, but also report for the first time that c-Rel is downregulated in HIV-1-infected cells specifically by interaction of Tat with NFκB binding sites on the promoter.
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Lo YT, Nadeau PE, Lin S, Mergia A. Establishing Restricted Expression of Caveolin-1 in HIV Infected Cells and Inhibition of Virus Replication. Open Microbiol J 2014; 8:114-21. [PMID: 25408776 PMCID: PMC4235073 DOI: 10.2174/1874285801408010114] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 09/22/2014] [Accepted: 10/02/2014] [Indexed: 11/22/2022] Open
Abstract
Background: Caveolin-1 (Cav-1) is the major protein of the caveolae and plays a role in multiple cellular functions and implicated to have anti-HIV activity. Regulated expression of Cav-1 is important for safe and effective use in order to exploit Cav-1 for HIV therapeutic applications. Methods: A series of Cav-1 and GFP expression vectors were constructed under the control of the HIV LTR for conditional expression or CMV promoter and the expression of Cav-1 was monitored in the presence or absence of Tat or HIV infection in order to establish the restricted expression of Cav-1 to HIV infected cells. Results: Cav-1 expression was evident under the control of the HIV LTR in the absence of Tat or HIV infection as demonstrated by immunoblot. Placing two internal ribosomal entry sequences (IRES) and a Rev response element, RRE (5’~ LTR-IRES-GFP-RRE-IRES-Cav-1~3’) resulted in no expression of Cav-1 in the absence of Tat with effective expression in the presence of Tat. Transduction of HIV permissive cells with this construct using a foamy virus vector show that Cav-1 was able to inhibit HIV replication by 82%. Cells that received LTR-IRES-GFP-RRE-IRES-Cav-1 remain healthy in the absence of Tat or HIV infection. Conclusion: These results taken together reveal the inclusion of two IRES establishes a significant reduction of leak through expression of Cav-1 in the absence of Tat or HIV infection. Such regulated expression will have therapeutic application of Cav-1 for HIV infection as well as broad applications which can be beneficial for other host-targeted interventions as therapeutics.
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Affiliation(s)
- Yung-Tsun Lo
- Department of Infectious Disease and Pathology, University of Florida, Gainesville, FL 32611, USA
| | - Peter E Nadeau
- Department of Infectious Disease and Pathology, University of Florida, Gainesville, FL 32611, USA
| | - Shanshan Lin
- Department of Infectious Disease and Pathology, University of Florida, Gainesville, FL 32611, USA
| | - Ayalew Mergia
- Department of Infectious Disease and Pathology, University of Florida, Gainesville, FL 32611, USA
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16
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Identification of molecular sub-networks associated with cell survival in a chronically SIVmac-infected human CD4+ T cell line. Virol J 2014; 11:152. [PMID: 25163480 PMCID: PMC4163169 DOI: 10.1186/1743-422x-11-152] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 08/15/2014] [Indexed: 12/31/2022] Open
Abstract
Background The deciphering of cellular networks to determine susceptibility to infection by HIV or the related simian immunodeficiency virus (SIV) is a major challenge in infection biology. Results Here, we have compared gene expression profiles of a human CD4+ T cell line at 24 h after infection with a cell line of the same origin permanently releasing SIVmac. A new knowledge-based-network approach (Inter-Chain-Finder, ICF) has been used to identify sub-networks associated with cell survival of a chronically SIV-infected T cell line. Notably, the method can identify not only differentially expressed key hub genes but also non-differentially expressed, critical, ‘hidden’ regulators. Six out of the 13 predicted major hidden key regulators were among the landscape of proteins known to interact with HIV. Several sub-networks were dysregulated upon chronic infection with SIV. Most prominently, factors reported to be engaged in early stages of acute viral infection were affected, e.g. entry, integration and provirus transcription and other cellular responses such as apoptosis and proliferation were modulated. For experimental validation of the gene expression analyses and computational predictions, individual pathways/sub-networks and significantly altered key regulators were investigated further. We showed that the expression of caveolin-1 (Cav-1), the top hub in the affected protein-protein interaction network, was significantly upregulated in chronically SIV-infected CD4+ T cells. Cav-1 is the main determinant of caveolae and a central component of several signal transduction pathways. Furthermore, CD4 downregulation and modulation of the expression of alternate and co-receptors as well as pathways associated with viral integration into the genome were also observed in these cells. Putatively, these modifications interfere with re-infection and the early replication cycle and inhibit cell death provoked by syncytia formation and bystander apoptosis. Conclusions Thus, by using the novel approach for network analysis, ICF, we predict that in the T cell line chronically infected with SIV, cellular processes that are known to be crucial for early phases of HIV/SIV replication are altered and cellular responses that result in cell death are modulated. These modifications presumably contribute to cell survival despite chronic infection. Electronic supplementary material The online version of this article (doi:10.1186/1743-422X-11-152) contains supplementary material, which is available to authorized users.
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García Cordero J, León Juárez M, González-Y-Merchand JA, Cedillo Barrón L, Gutiérrez Castañeda B. Caveolin-1 in lipid rafts interacts with dengue virus NS3 during polyprotein processing and replication in HMEC-1 cells. PLoS One 2014; 9:e90704. [PMID: 24643062 PMCID: PMC3958351 DOI: 10.1371/journal.pone.0090704] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 01/18/2014] [Indexed: 01/10/2023] Open
Abstract
Lipid rafts are ordered microdomains within cellular membranes that are rich in cholesterol and sphingolipids. Caveolin (Cav-1) and flotillin (Flt-1) are markers of lipid rafts, which serve as an organizing center for biological phenomena and cellular signaling. Lipid rafts involvement in dengue virus (DENV) processing, replication, and assembly remains poorly characterized. Here, we investigated the role of lipid rafts after DENV endocytosis in human microvascular endothelial cells (HMEC-1). The non-structural viral proteins NS3 and NS2B, but not NS5, were associated with detergent-resistant membranes. In sucrose gradients, both NS3 and NS2B proteins appeared in Cav-1 and Flt-1 rich fractions. Additionally, double immunofluorescence staining of DENV-infected HMEC-1 cells showed that NS3 and NS2B, but not NS5, colocalized with Cav-1 and Flt-1. Furthermore, in HMEC-1cells transfected with NS3 protease, shown a strong overlap between NS3 and Cav-1, similar to that in DENV-infected cells. In contrast, double-stranded viral RNA (dsRNA) overlapped weakly with Cav-1 and Flt-1. Given these results, we investigated whether Cav-1 directly interacted with NS3. Cav-1 and NS3 co-immunoprecipitated, indicating that they resided within the same complex. Furthermore, when cellular cholesterol was depleted by methyl-beta cyclodextrin treatment after DENV entrance, lipid rafts were disrupted, NS3 protein level was reduced, besides Cav-1 and NS3 were displaced to fractions 9 and 10 in sucrose gradient analysis, and we observed a dramatically reduction of DENV particles release. These data demonstrate the essential role of caveolar cholesterol-rich lipid raft microdomains in DENV polyprotein processing and replication during the late stages of the DENV life cycle.
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Affiliation(s)
- Julio García Cordero
- Departamento de Biomedicina Molecular, Centro de Investigación y Estudios Avanzados del IPN, México City, México
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas IPN, México City, México
| | - Moisés León Juárez
- Departamento de Biomedicina Molecular, Centro de Investigación y Estudios Avanzados del IPN, México City, México
| | | | - Leticia Cedillo Barrón
- Departamento de Biomedicina Molecular, Centro de Investigación y Estudios Avanzados del IPN, México City, México
- * E-mail: (BGC); (LCB)
| | - Benito Gutiérrez Castañeda
- Laboratorio de Inmunología, Facultad de Estudios Superiores Iztacala Universidad Autónoma de México, Tlalnepantla Estado de México, México
- * E-mail: (BGC); (LCB)
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Che X, Fan XQ, Wang ZL. Mechanism of blood-retinal barrier breakdown induced by HIV-1 (Review). Exp Ther Med 2014; 7:768-772. [PMID: 24660027 PMCID: PMC3961112 DOI: 10.3892/etm.2014.1521] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 01/28/2014] [Indexed: 01/23/2023] Open
Abstract
Human immunodeficiency virus (HIV)-1 has been detected in ocular tissues; however, the mechanism of entry has not been established. It has been hypothesized that the blood-retinal barrier (BRB), a critical guardian against microbial invasion of the eye, may be compromised in the presence of HIV-1 in the eye. In vivo and in vitro model systems have shown that the breach of tight junctions induced by HIV-1-associated factors contributes to the breakdown of the BRB. The present study reviews the mechanism of tight junction disruption, focusing on signaling pathways, the expression of enzymes, including metalloproteinases, and cytokines that affect inflammation. The studied pathways may be potential targets for the prevention of ocular HIV complications.
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Affiliation(s)
- Xin Che
- Department of Ophthalmology, Ninth People's Hospital Affiliated with Shanghai Jiaotong University, Shanghai 200011, P.R. China ; Key Laboratory of Ophthamology, Ninth People's Hospital Affiliated with Shanghai Jiaotong University, Shanghai 200011, P.R. China
| | - Xian-Qun Fan
- Department of Ophthalmology, Ninth People's Hospital Affiliated with Shanghai Jiaotong University, Shanghai 200011, P.R. China
| | - Zhi-Liang Wang
- Department of Ophthalmology, Ninth People's Hospital Affiliated with Shanghai Jiaotong University, Shanghai 200011, P.R. China
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Lin S, Nadeau PE, Wang X, Mergia A. Caveolin-1 reduces HIV-1 infectivity by restoration of HIV Nef mediated impairment of cholesterol efflux by apoA-I. Retrovirology 2012; 9:85. [PMID: 23067370 PMCID: PMC3487900 DOI: 10.1186/1742-4690-9-85] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 09/26/2012] [Indexed: 11/12/2022] Open
Abstract
Background HIV infection results in inhibited cholesterol efflux by apolipoprotein A-I (apoA-I) in macrophages, and this impairment involves Nef mediated down-regulation and redistribution of ATP-binding cassette transporter A1 (ABCA-1). We investigated the effect of caveolin-1 (Cav-1) on the cholesterol efflux by apoA-I in HIV infected primary and THP-1 cell-differentiated macrophages as well as astrocyte derived glioblastoma U87 cells. Results Our results reveal that Cav-1 restores the Nef -mediated impairment of cholesterol efflux by apoA-I in both cell types. Co-immunoprecipitation studies indicate a physical association of Cav-1 and Nef. The level of ABCA-1 expression remains the same whether Cav-1 is over-expressed or not. In addition, we examined the cholesterol composition of HIV particles released from Cav-1 treated cells and identified that the cholesterol content is dramatically reduced. The infectivity level of these virus particles is also significantly decreased. Conclusions These observations suggest that the interplay of Cav-1 with Nef and cholesterol subsequently counters Nef induced impairment of cholesterol efflux by apoA-l. The findings provide a cellular mechanism by which Cav-1 has an ability to restore HIV mediated impairment of cholesterol efflux in macrophages. This subsequently influences the cholesterol content incorporated into virus particles thereby inhibiting HIV infectivity and contributing to HIV’s persistent infection of macrophages.
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Affiliation(s)
- Shanshan Lin
- Department of Infectious Disease and Pathology, University of Florida, Gainesville, Florida, 32611, USA
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20
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Caveolin-1 suppresses human immunodeficiency virus-1 replication by inhibiting acetylation of NF-κB. Virology 2012; 432:110-9. [PMID: 22748181 DOI: 10.1016/j.virol.2012.05.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 03/24/2012] [Accepted: 05/22/2012] [Indexed: 12/22/2022]
Abstract
Caveolin-1 is an integral membrane protein primarily responsible for the formation of membrane structures known as caveolae. Caveolae are specialized lipid rafts involved in protein trafficking, cholesterol homeostasis, and a number of signaling functions. It has been demonstrated that caveolin-1 suppresses HIV-1 protein expression. We found that co-transfecting cells with HIV-1 and caveolin-1 constructs, results in a marked decrease in the level of HIV-1 transcription relative to cells transfected with HIV-1 DNA alone. Correspondingly, reduction of endogenous caveolin-1 expression by siRNA-mediated silencing resulted in an enhancement of HIV-1 replication. Further, we observed a loss of caveolin-mediated suppression of HIV-1 transcription in promoter studies with reporters containing mutations in the NF-κB binding site. Our analysis of the posttranslational modification status of the p65 subunit of NF-κB demonstrates hypoacetylation of p65 in the presence of caveolin-1. Since hypoacetylated p65 has been shown to inhibit transcription, we conclude that caveolin-1 inhibits HIV-1 transcription through a NF-κB-dependent mechanism.
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21
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Bandorowicz-Pikula J, Wos M, Pikula S. Do annexins participate in lipid messenger mediated intracellular signaling? A question revisited. Mol Membr Biol 2012; 29:229-42. [PMID: 22694075 DOI: 10.3109/09687688.2012.693210] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Annexins are physiologically important proteins that play a role in calcium buffering but also influence membrane structure, participate in Ca²⁺-dependent membrane repair events and in remodelling of the cytoskeleton. Thirty years ago several peptides isolated from lung perfusates, peritoneal leukocytes, neutrophiles and renal cells were proven inhibitory to the activity of phospholipase A₂. Those peptides were found to derive from structurally related proteins: annexins AnxA1 and AnxA2. These findings raised the question whether annexins may participate in regulation of the production of lipid second messengers and, therefore, modulate numerous lipid mediated signaling pathways in the cell. Recent advances in the field of annexins made also with the use of knock-out animal models revealed that these proteins are indeed important constituents of specific signaling pathways. In this review we provide evidence supporting the hypothesis that annexins, as membrane-binding proteins and organizers of the membrane lateral heterogeneity, may participate in lipid mediated signaling pathways by affecting the distribution and activity of lipid metabolizing enzymes (most of the reports point to phospholipase A₂) and of protein kinases regulating activity of these enzymes. Moreover, some experimental data suggest that annexins may directly interact with lipid metabolizing enzymes and, in a calcium-dependent or independent manner, with some of their substrates and products. On the basis of these observations, many investigators suggest that annexins are capable of linking Ca²⁺, redox and lipid signaling to coordinate vital cellular responses to the environmental stimuli.
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Affiliation(s)
- Joanna Bandorowicz-Pikula
- Laboratory of Cellular Metabolism, Department of Biochemistry, Nencki Institute of Experimental Biology, PL 02-093 Warsaw, Poland.
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22
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Domon M, Nasir MN, Matar G, Pikula S, Besson F, Bandorowicz-Pikula J. Annexins as organizers of cholesterol- and sphingomyelin-enriched membrane microdomains in Niemann-Pick type C disease. Cell Mol Life Sci 2012; 69:1773-85. [PMID: 22159585 PMCID: PMC11114673 DOI: 10.1007/s00018-011-0894-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 11/17/2011] [Accepted: 11/21/2011] [Indexed: 01/22/2023]
Abstract
Growing evidence suggests that membrane microdomains enriched in cholesterol and sphingomyelin are sites for numerous cellular processes, including signaling, vesicular transport, interaction with pathogens, and viral infection, etc. Recently some members of the annexin family of conserved calcium and membrane-binding proteins have been recognized as cholesterol-interacting molecules and suggested to play a role in the formation, stabilization, and dynamics of membrane microdomains to affect membrane lateral organization and to attract other proteins and signaling molecules onto their territory. Furthermore, annexins were implicated in the interactions between cytosolic and membrane molecules, in the turnover and storage of cholesterol and in various signaling pathways. In this review, we focus on the mechanisms of interaction of annexins with lipid microdomains and the role of annexins in membrane microdomains dynamics including possible participation of the domain-associated forms of annexins in the etiology of human lysosomal storage disease called Niemann-Pick type C disease, related to the abnormal storage of cholesterol in the lysosome-like intracellular compartment. The involvement of annexins and cholesterol/sphingomyelin-enriched membrane microdomains in other pathologies including cardiac dysfunctions, neurodegenerative diseases, obesity, diabetes mellitus, and cancer is likely, but is not supported by substantial experimental observations, and therefore awaits further clarification.
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Affiliation(s)
- Magdalena Domon
- Laboratory of Lipid Biochemistry, Department of Biochemistry, Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093, Warsaw, Poland
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Function of membrane rafts in viral lifecycles and host cellular response. Biochem Res Int 2011; 2011:245090. [PMID: 22191032 PMCID: PMC3235436 DOI: 10.1155/2011/245090] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 08/31/2011] [Accepted: 09/27/2011] [Indexed: 12/31/2022] Open
Abstract
Membrane rafts are small (10–200 nm) sterol- and sphingolipid-enriched domains that compartmentalize cellular processes. Membrane rafts play an important role in viral infection cycles and viral virulence. Viruses are divided into four main classes, enveloped DNA virus, enveloped RNA virus, nonenveloped DNA virus, and nonenveloped RNA virus. General virus infection cycle is also classified into two sections, the early stage (entry process) and the late stage (assembly, budding, and release processes of virus particles). In the viral cycle, membrane rafts act as a scaffold of many cellular signal transductions, which are associated with symptoms caused by viral infections. In this paper, we describe the functions of membrane rafts in viral lifecycles and host cellular response according to each virus classification, each stage of the virus lifecycle, and each virus-induced signal transduction.
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Mo S, Yang S, Cui Z. New glimpses of caveolin-1 functions in embryonic development and human diseases. FRONTIERS IN BIOLOGY 2011; 6:367. [PMID: 32215005 PMCID: PMC7089126 DOI: 10.1007/s11515-011-1132-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 12/30/2010] [Indexed: 11/17/2022]
Abstract
Caveolin-1 (Cav-1) isoforms, including Cav-1α and Cav-1β, were identified as integral membrane proteins and the major components of caveolae. Cav-1 proteins are highly conserved during evolution from {itCaenorhabditis elegans} to human and are capable of interacting with many signaling molecules through their caveolin scaffolding domains to regulate the activities of multiple signaling pathways. Thus, Cav-1 plays crucial roles in the regulation of cellular proliferation, differentiation and apoptosis in a cell-specific and contextual manner. In addition, Cav-1 is essential for embryonic development of vertebrates owing to its regulation of BMP, Wnt, TGF-β and other key signaling molecules. Moreover, Cav-1 is mainly expressed in terminally differentiated cells and its abnormal expression is often associated with human diseases, such as tumor progression, cardiovascular diseases, fibrosis, lung regeneration, and diseases related to virus. In this review, we will further discuss the potential of Cav-1 as a target for disease therapy and multiple drug resistance.
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Affiliation(s)
- Saijun Mo
- Department of Basic Oncology, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001 China
| | - Shengli Yang
- Department of Basic Oncology, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001 China
| | - Zongbin Cui
- Key Laboratory of Biodiversity and Conservation of Aquatic Organism, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072 China
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Caveolin 1 inhibits HIV replication by transcriptional repression mediated through NF-κB. J Virol 2011; 85:5483-93. [PMID: 21430048 DOI: 10.1128/jvi.00254-11] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Caveolin 1 (Cav-1), the scaffold protein of a specific membrane lipid raft called caveolae, has been reported to suppress HIV-1 replication. However, the mechanism by which Cav-1 inhibits HIV replication remains unclear. In this study, we investigated the mechanism by which Cav-1 inhibits HIV replication at the level of gene expression. Our results show that Cav-1 represses viral gene expression and that this suppression involves the NF-κB pathway. We used several approaches in different cell types, including primary CD4(+) T cells and macrophages, to demonstrate the role of nuclear factor κB (NF-κB) in Cav-1-mediated inhibition of viral expression. A mutational analysis of the cis-acting element shows that the two NF-κB sites in the U3 region of the long terminal repeat (LTR) are critical for Cav-1-mediated inhibition of viral expression. In the presence of Cav-1, phosphorylation of IKKβ, IKKα, IκBα, and NF-κB p65 is dramatically reduced, while viral gene expression is suppressed. In addition, translocation of NF-κB p65 to the nucleus decreases substantially in the presence of Cav-1. Furthermore, significant inhibition of NF-κB activation and binding to target DNA are evident in the presence of Cav-1. These results establish evidence that Cav-1 inhibits HIV replication by transcriptional repression of viral gene expression and contributes to HIV's persistent infection of macrophages.
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