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Xu J, Liu X, Zhang X, Marshall B, Dong Z, Smith SB, Espinosa-Heidmann DG, Zhang M. Retinal and Choroidal Pathologies in Aged BALB/c Mice Following Systemic Neonatal Murine Cytomegalovirus Infection. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:1787-1804. [PMID: 34197777 PMCID: PMC8485058 DOI: 10.1016/j.ajpath.2021.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/04/2021] [Accepted: 06/14/2021] [Indexed: 11/30/2022]
Abstract
Although pathologies associated with acute virus infections have been extensively studied, the effects of long-term latent virus infections are less well understood. Human cytomegalovirus, which infects 50% to 80% of humans, is usually acquired during early life and persists in a latent state for the lifetime. The purpose of this study was to determine whether systemic murine cytomegalovirus (MCMV) infection acquired early in life disseminates to and becomes latent in the eye and if ocular MCMV can trigger in situ inflammation and occurrence of ocular pathology. This study found that neonatal infection of BALB/c mice with MCMV resulted in dissemination of virus to the eye, where it localized principally to choroidal endothelia and pericytes and less frequently to the retinal pigment epithelium (RPE) cells. MCMV underwent ocular latency, which was associated with expression of multiple virus genes and from which MCMV could be reactivated by immunosuppression. Latent ocular infection was associated with significant up-regulation of several inflammatory/angiogenic factors. Retinal and choroidal pathologies developed in a progressive manner, with deposits appearing at both basal and apical aspects of the RPE, RPE/choroidal atrophy, photoreceptor degeneration, and neovascularization. The pathologies induced by long-term ocular MCMV latency share features of previously described human ocular diseases, such as age-related macular degeneration.
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Affiliation(s)
- Jinxian Xu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia; James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Xinglou Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia; James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Xinyan Zhang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia; James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Brendan Marshall
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Zheng Dong
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia; Charlie Norwood Veterans Affairs Medical Center, Augusta, Georgia
| | - Sylvia B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia; James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia; Department of Ophthamology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Diego G Espinosa-Heidmann
- James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia; Department of Ophthamology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Ming Zhang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia; James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia.
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The Role of Caspase-12 in Retinal Bystander Cell Death and Innate Immune Responses against MCMV Retinitis. Int J Mol Sci 2021; 22:ijms22158135. [PMID: 34360899 PMCID: PMC8348425 DOI: 10.3390/ijms22158135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/29/2021] [Accepted: 07/04/2021] [Indexed: 11/25/2022] Open
Abstract
(1) Background: caspase-12 is activated during cytomegalovirus retinitis, although its role is presently unclear. (2) Methods: caspase-12−/− (KO) or caspase-12+/+ (WT) mice were immunosup eyes were analyzed by plaque assay, TUNEL assay, immunohistochemical staining, western blotting, and real-time PCR. (3) Results: increased retinitis and a more extensive virus spread were detected in the retina of infected eyes of KO mice compared to WT mice at day 14 p.i. Compared to MCMV injected WT eyes, mRNA levels of interferons α, β and γ were significantly reduced in the neural retina of MCMV-infected KO eyes at day 14 p.i. Although similar numbers of MCMV infected cells, similar virus titers and similar numbers of TUNEL-staining cells were detected in injected eyes of both KO and WT mice at days 7 and 10 p.i., significantly lower amounts of cleaved caspase-3 and p53 protein were detected in infected eyes of KO mice at both time points. (4) Conclusions: caspase-12 contributes to caspase-3-dependent and independent retinal bystander cell death during MCMV retinitis and may also play an important role in innate immunity against virus infection of the retina.
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Yu Z, Wang Y, Liu L, Zhang X, Jiang S, Wang B. Apoptosis Disorder, a Key Pathogenesis of HCMV-Related Diseases. Int J Mol Sci 2021; 22:ijms22084106. [PMID: 33921122 PMCID: PMC8071541 DOI: 10.3390/ijms22084106] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/09/2021] [Accepted: 04/13/2021] [Indexed: 02/07/2023] Open
Abstract
Human cytomegalovirus (HCMV) belongs to the β-herpesvirus family, which is transmitted in almost every part of the world and is carried by more than 90% of the general population. Increasing evidence indicates that HCMV infection triggers numerous diseases by disrupting the normal physiological activity of host cells, particularly apoptosis. Apoptosis disorder plays a key role in the initiation and development of multiple diseases. However, the relationship and molecular mechanism of HCMV-related diseases and apoptosis have not yet been systematically summarized. This review aims to summarize the role of apoptosis in HCMV-related diseases and provide an insight into the molecular mechanism of apoptosis induced by HCMV infection. We summarize the literature on HCMV-related diseases and suggest novel strategies for HCMV treatment by regulating apoptosis.
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Affiliation(s)
- Zhongjie Yu
- Department of Special Medicine, School of Basic Medicine, Qingdao Medical College, Qingdao University, Qingdao 266000, China;
| | - Yashuo Wang
- College of Life Sciences, Qingdao University, Qingdao 266000, China;
| | - Lili Liu
- Department of Basic Medicine, School of Basic Medicine, Qingdao Medical College, Qingdao University, Qingdao 266000, China;
| | - Xianjuan Zhang
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao Medical College, Qingdao University, Qingdao 266000, China; (X.Z.); (S.J.)
| | - Shasha Jiang
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao Medical College, Qingdao University, Qingdao 266000, China; (X.Z.); (S.J.)
| | - Bin Wang
- Department of Special Medicine, School of Basic Medicine, Qingdao Medical College, Qingdao University, Qingdao 266000, China;
- Correspondence: ; Tel.: +86-136-8532-6203
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Xu J, Mo J, Liu X, Marshall B, Atherton SS, Dong Z, Smith S, Zhang M. Depletion of the Receptor-Interacting Protein Kinase 3 (RIP3) Decreases Photoreceptor Cell Death During the Early Stages of Ocular Murine Cytomegalovirus Infection. Invest Ophthalmol Vis Sci 2019; 59:2445-2458. [PMID: 29847649 PMCID: PMC5957522 DOI: 10.1167/iovs.18-24086] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Purpose The purpose of this study was to determine if the receptor-interacting protein kinase 3 (RIP3) plays a significant role in innate immune responses and death of bystander retinal neurons during murine cytomegalovirus (MCMV) retinal infection, by comparing the innate immune response and cell death in RIP3-depleted mice (Rip3−/−) and Rip3+/+ control mice. Methods Rip3−/− and Rip3+/+ mice were immunosuppressed (IS) and inoculated with MCMV via the supraciliary route. Virus-injected and mock-injected control eyes were removed at days 4, 7, and 10 post infection (p.i.) and markers of innate immunity and cell death were analyzed. Results Compared to Rip3+/+ mice, significantly more MCMV was recovered and more MCMV-infected RPE cells were observed in injected eyes of Rip3−/− mice at days 4 and 7 p.i. In contrast, fewer TUNEL-stained photoreceptors were observed in Rip3−/− eyes than in Rip3+/+ eyes at these times. Electron microscopy showed that significantly more apoptotic photoreceptor cells were present in Rip3+/+ mice than in Rip3−/− mice. Immunohistochemistry showed that the majority of TUNEL-stained photoreceptors died via mitochondrial flavoprotein apoptosis-inducing factor (AIF)-mediated, caspase 3–independent apoptosis. The majority of RIP3-expressing cells in infected eyes were RPE cells, microglia/macrophages, and glia, whereas retinal neurons contained much lower amounts of RIP3. Western blots showed significantly higher levels of activated nuclear factor–κB and caspase 1 were present in Rip3+/+ eyes compared to Rip3−/− eyes. Conclusions Our results suggest that RIP3 enhances innate immune responses against ocular MCMV infection via activation of the inflammasome and nuclear factor–κB, which also leads to inflammation and death of bystander cells by multiple pathways including apoptosis and necroptosis.
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Affiliation(s)
- Jinxian Xu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States.,James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Juan Mo
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Xinglou Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States.,James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Brendan Marshall
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Sally S Atherton
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Zheng Dong
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Sylvia Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States.,James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Ming Zhang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States.,James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
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Mo J, Marshall B, Covar J, Zhang NY, Smith SB, Atherton SS, Zhang M. Role of Bax in death of uninfected retinal cells during murine cytomegalovirus retinitis. Invest Ophthalmol Vis Sci 2014; 55:7137-46. [PMID: 25298417 DOI: 10.1167/iovs.14-15404] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Extensive death of uninfected bystander neuronal cells is an important component of the pathogenesis of cytomegalovirus retinitis. Our previous results have shown that caspase 3-dependent and -independent pathways are involved in death of uninfected bystander cells during murine cytomegalovirus (MCMV) retinitis and also that Bcl-2, an important inhibitor of apoptosis via the Bax-mediated mitochondrial pathway, is downregulated during this process. The purpose of this study was to determine whether Bax-mediated mitochondrial damage has a significant role in the death of uninfected retinal cells. METHODS BALB/c mice, Bax(-/-) mice, or Bax(+/+) mice were immunosuppressed with methylprednisolone and infected with 5 × 10(3) plaque-forming units (PFU) of the K181 strain of MCMV via the supraciliary route. Injected eyes were analyzed by plaque assay, electron microscopy, hematoxylin and eosin (H&E) staining, TUNEL assay, Western blot (for caspase 3, caspase 12, Bax, receptor interacting protein-1 [RIP1] and receptor interacting protein-3 [RIP3]), as well as immunohistochemical staining for MCMV early antigen and cleaved caspase 3. RESULTS Significantly more Bax was detected in mitochondrial fractions of MCMV-infected eyes than in mitochondrial fractions of mock-infected control eyes. Furthermore, the level of cleaved caspase 3 was significantly lower in MCMV-infected Bax(-/-) eyes than in MCMV-infected Bax(+/+) eyes. However, more caspase 3-independent cell death of uninfected bystander retinal cells and more cleaved RIP1 were observed in Bax(-/-) than in Bax(+/+) eyes. CONCLUSIONS During MCMV retinitis, Bax is activated and has an important role in death of uninfected bystander retinal cells by caspase 3-dependent apoptosis. Although the exact mechanism remains to be deciphered, active Bax might also prevent death of some types of uninfected retinal cells by a caspase 3-independent pathway.
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Affiliation(s)
- Juan Mo
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States
| | - Brendan Marshall
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States
| | - Jason Covar
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States
| | - Nancy Y Zhang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States
| | - Sylvia B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States
| | - Sally S Atherton
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States The James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States
| | - Ming Zhang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States The James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States
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Risk Factors for Cytomegalovirus Retinitis in Patients with Cytomegalovirus Viremia after Hematopoietic Stem Cell Transplantation. Ophthalmology 2012; 119:1892-8. [DOI: 10.1016/j.ophtha.2012.03.032] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 03/16/2012] [Accepted: 03/16/2012] [Indexed: 11/21/2022] Open
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Dou J, Li X, Cai Y, Chen H, Zhu S, Wang Q, Zou X, Mei Y, Yang Q, Li W, Han Y. Human cytomegalovirus induces caspase-dependent apoptosis of megakaryocytic CHRF-288-11 cells by activating the JNK pathway. Int J Hematol 2010; 91:620-9. [PMID: 20376580 DOI: 10.1007/s12185-010-0560-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 03/14/2010] [Accepted: 03/16/2010] [Indexed: 11/30/2022]
Abstract
Human cytomegalovirus (HCMV) infection is usually implicated in thrombocytopenia occurring in newborns and immunocompromised patients. However, the underlying mechanisms remain elusive. This study was conducted to investigate the effects of HCMV infection on the viability of megakaryocytic CHRF-288-11 cells and the underlying mechanisms involved. RT-PCR for determining mRNA expression of HCMV immediate early gene 1 and Western blot for measuring protein expression of late HCMV gene pp65 showed that CHRF-288-11 cells were susceptible to HCMV infection. HCMV infection reduced the viability of CHRF-288-11 cells via apoptosis in a dose- and time-dependent manner. Both caspase 3 and c-Jun terminal kinase (JNK) signaling pathway were activated in the HCMV-treated CHRF-288-11 cells. z-DEVD-fmk (a caspase inhibitor) and SP600125 (a JNK inhibitor) significantly prevented the death of CHRF-288-11 cells induced by HCMV, respectively. Furthermore, inhibition of JNK activity could reduce the formation of active caspase 3 induced by HCMV. Interestingly, the co-application of antivirus drug ganciclovir and SP600125 synergistically prevented the death of CHRF-288-11 cells induced by HCMV. Collectively, these findings suggest that HCMV infection may induce the caspase-dependent apoptosis of megakaryocytic CHRF-288-11 cells by the activation of JNK signaling pathway.
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Affiliation(s)
- Juan Dou
- Department of Pediatrics, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
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Abstract
The human immunodeficiency virus (HIV), the cause of AIDS, has infected an estimated 33 million individuals worldwide. HIV is associated with immunodeficiency, neoplasia, and neurologic disease. The continuing evolution of the HIV epidemic has spurred an intense interest in a hitherto neglected area of medicine, neuroinfectious diseases and their consequences. This work has broad applications for the study of central nervous system (CNS) tumors, dementias, neuropathies, and CNS disease in other immunosuppressed individuals. HIV is neuroinvasive (can enter the CNS), neurotrophic (can live in neural tissues), and neurovirulent (causes disease of the nervous system). This article reviews the HIV-associated neurologic syndromes, which can be classified as primary HIV neurologic disease (in which HIV is both necessary and sufficient to cause the illness), secondary or opportunistic neurologic disease (in which HIV interacts with other pathogens, resulting in opportunistic infections and tumors), and treatment-related neurologic disease (such as immune reconstitution inflammatory syndrome).
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Affiliation(s)
- Elyse J Singer
- Department of Neurology, David Geffen School of Medicine at UCLA, 11645 Wilshire Boulevard, Suite 770, Los Angeles, CA 90025, USA.
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Patil AJ, Gramajo AL, Sharma A, Chwa M, Seigel GM, Kuppermann BD, Kenney MC. Effects of Benzo(e)Pyrene on the Retinal Neurosensory Cells and Human Microvascular Endothelial CellsIn Vitro. Curr Eye Res 2009; 34:672-82. [DOI: 10.1080/02713680903015892] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Apoptotic mechanisms within the retina in Staphylococcus epidermidis experimental endophthalmitis. Graefes Arch Clin Exp Ophthalmol 2008; 247:667-74. [DOI: 10.1007/s00417-008-0996-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2008] [Revised: 10/21/2008] [Accepted: 10/29/2008] [Indexed: 10/21/2022] Open
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Bai L, Zhang Z, Zhang H, Li X, Yu Q, Lin H, Yang W. HIV-1 Tat protein alter the tight junction integrity and function of retinal pigment epithelium: an in vitro study. BMC Infect Dis 2008; 8:77. [PMID: 18538010 PMCID: PMC2430207 DOI: 10.1186/1471-2334-8-77] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Accepted: 06/06/2008] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND How HIV-1 enter into the eyes remains obscure. We postulated that HIV-1 Tat protein can alter the expression of specific tight-junction proteins and disturb the blood retinal barrier, and contributes to HIV trafficking into the eyes. This study is to determine the effects of HIV-1 Tat proteins on the barrier function and tight-junction protein expression of retinal pigment epithelial cell (RPE). METHODS A human RPE cell line (D407) cultured on microporous filter-supports was used. After treating with HIV-1 Tat protein, transepithelial electrical resistance (TER) of confluent RPE cells was measured by epithelial voltmeter. The permeability of the RPE cells to sodium fluorescein was measured. The expressions of the occludin and claudins were determined by real-time polymerase chain reaction, immunofluorescence, and Western blot analysis. Activation of ERK1/2 was detected by Western blot analysis with specific antiphospho protein antibodies. NF-kappaB DNA binding activity was determined by transcription factor assay. Specific pharmacologic inhibitors directed against the MAPKs were used to analyze the signaling involved in barrier destruction of RPE cells exposed to HIV-1 Tat. RESULTS Treating cultured human retinal pigment epithelial cells with 100 nM Tat for 24 hours increased the permeability and decreased the TER of the epithelial monolayer. HIV-1 Tat also disrupted and downregulated the tight-junction proteins claudin-1, claudin-3, and claudin-4 in these cells, whereas claudin-2 was upregulated, and the expression of occludin was unaffected. HIV-1 Tat protein also induced activation of ERK1/2 and NF-kappaB. HIV-1 Tat protein induced barrier destruction, changes in expression of TJs, and activation of ERK1/2 and NF-kappaB were abrogated by inhibitor of ERK1/2 and NF-kappaB. CONCLUSION HIV-1 Tat protein causes increases in the paracellular permeability of RPE cells in vitro concomitant with changes in expression of certain transmembrane proteins associated with the tight junction. The effects of HIV-1 Tat on barrier function of the RPE may be mediated by ERK MAPK and NF-kappaB activation, which may represent potential targets for novel therapeutic approaches for the retinopathy induced by HIV infection.
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Affiliation(s)
- Ling Bai
- Key Laboratory of Ophthalmology, Ministry of Education; Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, PR China.
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Poncet D, Pauleau AL, Szabadkai G, Vozza A, Scholz SR, Le Bras M, Brière JJ, Jalil A, Le Moigne R, Brenner C, Hahn G, Wittig I, Schägger H, Lemaire C, Bianchi K, Souquère S, Pierron G, Rustin P, Goldmacher VS, Rizzuto R, Palmieri F, Kroemer G. Cytopathic effects of the cytomegalovirus-encoded apoptosis inhibitory protein vMIA. ACTA ACUST UNITED AC 2006; 174:985-96. [PMID: 16982800 PMCID: PMC2064390 DOI: 10.1083/jcb.200604069] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Replication of human cytomegalovirus (CMV) requires the expression of the viral mitochondria–localized inhibitor of apoptosis (vMIA). vMIA inhibits apoptosis by recruiting Bax to mitochondria, resulting in its neutralization. We show that vMIA decreases cell size, reduces actin polymerization, and induces cell rounding. As compared with vMIA-expressing CMV, vMIA-deficient CMV, which replicates in fibroblasts expressing the adenoviral apoptosis suppressor E1B19K, induces less cytopathic effects. These vMIA effects can be separated from its cell death–inhibitory function because vMIA modulates cellular morphology in Bax-deficient cells. Expression of vMIA coincided with a reduction in the cellular adenosine triphosphate (ATP) level. vMIA selectively inhibited one component of the ATP synthasome, namely, the mitochondrial phosphate carrier. Exposure of cells to inhibitors of oxidative phosphorylation produced similar effects, such as an ATP level reduced by 30%, smaller cell size, and deficient actin polymerization. Similarly, knockdown of the phosphate carrier reduced cell size. Our data suggest that the cytopathic effect of CMV can be explained by vMIA effects on mitochondrial bioenergetics.
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Affiliation(s)
- Delphine Poncet
- Centre National de la Recherche Scientifique, FRE2939, Institut Gustave Roussy, F-94805 Villejuif, France
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Affiliation(s)
- Torsten W Wiegand
- Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, MA 02114, USA
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Scholz M, Doerr HW, Cinatl J. Human cytomegalovirus retinitis: pathogenicity, immune evasion and persistence. Trends Microbiol 2003; 11:171-8. [PMID: 12706995 DOI: 10.1016/s0966-842x(03)00066-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Human cytomegalovirus (HCMV) retinitis frequently occurs in severely naturally and iatrogenically immunocompromised patients. It has been shown that the immune-privileged retinal pigment epithelium (RPE) is a major site of persistent HCMV. Recently, evidence has accumulated to show that HCMV immediate early (IE) gene expression in RPE cells deviates ocular antiviral inflammation via FasL. Moreover, unlike in other cell types, the HCMV major IE1/2 enhancer promoter (MIEP) resists activation by proinflammatory stimuli mediated by the transcription factor NF-kappaB. However, tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) found at elevated levels in transplant recipients and AIDS patients with retinitis sensitize RPE cells and other retinal cells to FasL-mediated apoptosis, thus contributing to retina destruction and necrosis rather than inflammation. These specific features of RPE cells in conjunction with deregulated immune responses of immunocompromised patients seem to contribute to virus persistence and pathogenesis within the immune-privileged ocular retina.
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Affiliation(s)
- Martin Scholz
- Zentrum der Hygiene, Institut für Medizinische Virologie, Klinikum der Johann Wolfgang Goethe-Universität, Paul-Ehrlich-Strasse 40, D-60596 Frankfurt am Main, Germany
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