1
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Donadoni M, Huang W, Yarandi SS, Burdo TH, Chang SL, Sariyer IK. Modulation of OPRM1 Alternative Splicing by Morphine and HIV-1 Nef. J Neuroimmune Pharmacol 2022; 17:277-288. [PMID: 34420144 PMCID: PMC8859008 DOI: 10.1007/s11481-021-10009-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 08/06/2021] [Indexed: 12/29/2022]
Abstract
Clinically used opioids, such as morphine, activate the mu opioid receptor (MOR) encoded by Opioid Receptor Mu 1 (OPRM1) gene. Examination of the opioid receptor genes showed that the human OPRM1 pre-mRNA undergoes extensive alternative splicing events and capable of expressing 21 isoforms. However, characterization of OPRM1 signaling is generalized, and only one isoform (MOR-1) has been extensively studied. Compounding this issue is the increasing significance of intravenous drug abuse in HIV neuropathogenesis. Here, we investigated the molecular impact of morphine and HIV-1 on regulation of OPRM1 pre-mRNA splicing in in vitro and in vivo models. Our results suggested that morphine treatment specifically induces the alternative splicing of MOR-1X isoform among the other isoforms analyzed in neuronal cells. Interestingly, alternative splicing and expression of MOR-1X isoform was also induced in postmortem brain tissues obtained from people with HIV (PWH). Additionally, treatment of control rats with morphine induced alternative splicing of MOR-1X in the brain regions involved in the reward pathways. More interestingly, HIV-1 transgenic (HIV-1Tg) rats, showed an additive induction of MOR-1X isoform with the exposure to morphine. To further assess the possible role of HIV secretory proteins in alternative splicing of OPRM1 gene, we analyzed the impact of HIV-1 Tat, gp120 and Nef proteins on alternative splicing of MOR-1X isoform. While the Tat and gp120 had no visible effects, treatment of neurons with Nef induced MOR-1X alternative splicing that was comparable to treatment with morphine. Altogether, our results suggest that HIV-1 may alter MOR isoform expression with Nef protein by amplifying the rate of MOR-1X alternative splicing induced by morphine.
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Affiliation(s)
- Martina Donadoni
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, Philadelphia, PA, 19140, USA
| | - Wenfei Huang
- Institute of NeuroImmune Pharmacology and Department of Biological Sciences, Seton Hall University, South Orange, NJ, USA
| | - Shadan S Yarandi
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, Philadelphia, PA, 19140, USA
| | - Tricia H Burdo
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, Philadelphia, PA, 19140, USA
| | - Sulie L Chang
- Institute of NeuroImmune Pharmacology and Department of Biological Sciences, Seton Hall University, South Orange, NJ, USA.
| | - Ilker K Sariyer
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, Philadelphia, PA, 19140, USA.
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2
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Nickoloff-Bybel EA, Festa L, Meucci O, Gaskill PJ. Co-receptor signaling in the pathogenesis of neuroHIV. Retrovirology 2021; 18:24. [PMID: 34429135 PMCID: PMC8385912 DOI: 10.1186/s12977-021-00569-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 08/11/2021] [Indexed: 12/13/2022] Open
Abstract
The HIV co-receptors, CCR5 and CXCR4, are necessary for HIV entry into target cells, interacting with the HIV envelope protein, gp120, to initiate several signaling cascades thought to be important to the entry process. Co-receptor signaling may also promote the development of neuroHIV by contributing to both persistent neuroinflammation and indirect neurotoxicity. But despite the critical importance of CXCR4 and CCR5 signaling to HIV pathogenesis, there is only one therapeutic (the CCR5 inhibitor Maraviroc) that targets these receptors. Moreover, our understanding of co-receptor signaling in the specific context of neuroHIV is relatively poor. Research into co-receptor signaling has largely stalled in the past decade, possibly owing to the complexity of the signaling cascades and functions mediated by these receptors. Examining the many signaling pathways triggered by co-receptor activation has been challenging due to the lack of specific molecular tools targeting many of the proteins involved in these pathways and the wide array of model systems used across these experiments. Studies examining the impact of co-receptor signaling on HIV neuropathogenesis often show activation of multiple overlapping pathways by similar stimuli, leading to contradictory data on the effects of co-receptor activation. To address this, we will broadly review HIV infection and neuropathogenesis, examine different co-receptor mediated signaling pathways and functions, then discuss the HIV mediated signaling and the differences between activation induced by HIV and cognate ligands. We will assess the specific effects of co-receptor activation on neuropathogenesis, focusing on neuroinflammation. We will also explore how the use of substances of abuse, which are highly prevalent in people living with HIV, can exacerbate the neuropathogenic effects of co-receptor signaling. Finally, we will discuss the current state of therapeutics targeting co-receptors, highlighting challenges the field has faced and areas in which research into co-receptor signaling would yield the most therapeutic benefit in the context of HIV infection. This discussion will provide a comprehensive overview of what is known and what remains to be explored in regard to co-receptor signaling and HIV infection, and will emphasize the potential value of HIV co-receptors as a target for future therapeutic development. ![]()
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Affiliation(s)
- E A Nickoloff-Bybel
- Department of Pharmacology and Physiology, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, PA, 19102, USA
| | - L Festa
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, 240 S. 40th Street, Philadelphia, PA, 19104, USA
| | - O Meucci
- Department of Pharmacology and Physiology, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, PA, 19102, USA.,Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - P J Gaskill
- Department of Pharmacology and Physiology, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, PA, 19102, USA.
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3
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Lotz SK, Blackhurst BM, Reagin KL, Funk KE. Microbial Infections Are a Risk Factor for Neurodegenerative Diseases. Front Cell Neurosci 2021; 15:691136. [PMID: 34305533 PMCID: PMC8292681 DOI: 10.3389/fncel.2021.691136] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/08/2021] [Indexed: 12/13/2022] Open
Abstract
Neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, comprise a family of disorders characterized by progressive loss of nervous system function. Neuroinflammation is increasingly recognized to be associated with many neurodegenerative diseases but whether it is a cause or consequence of the disease process is unclear. Of growing interest is the role of microbial infections in inciting degenerative neuroinflammatory responses and genetic factors that may regulate those responses. Microbial infections cause inflammation within the central nervous system through activation of brain-resident immune cells and infiltration of peripheral immune cells. These responses are necessary to protect the brain from lethal infections but may also induce neuropathological changes that lead to neurodegeneration. This review discusses the molecular and cellular mechanisms through which microbial infections may increase susceptibility to neurodegenerative diseases. Elucidating these mechanisms is critical for developing targeted therapeutic approaches that prevent the onset and slow the progression of neurodegenerative diseases.
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Affiliation(s)
| | | | | | - Kristen E. Funk
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States
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4
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Pisani A, Donno R, Gennari A, Cibecchini G, Catalano F, Marotta R, Pompa PP, Tirelli N, Bardi G. CXCL12-PLGA/Pluronic Nanoparticle Internalization Abrogates CXCR4-Mediated Cell Migration. NANOMATERIALS 2020; 10:nano10112304. [PMID: 33233846 PMCID: PMC7699919 DOI: 10.3390/nano10112304] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 02/06/2023]
Abstract
Chemokine-induced chemotaxis mediates physiological and pathological immune cell trafficking, as well as several processes involving cell migration. Among them, the role of CXCL12/CXCR4 signaling in cancer and metastasis is well known, and CXCR4 has been often targeted with small molecule-antagonists or short CXCL12-derived peptides to limit the pathological processes of cell migration and invasion. To reduce CXCR4-mediated chemotaxis, we adopted a different approach. We manufactured poly(lactic acid-co-glycolic acid) (PLGA)/Pluronic F127 nanoparticles through microfluidics-assisted nanoprecipitation and functionalized them with streptavidin to docking a biotinylated CXCL12 to be exposed on the nanoparticle surface. Our results show that CXCL12-decorated nanoparticles are non-toxic and do not induce inflammatory cytokine release in THP-1 monocytes cultured in fetal bovine and human serum-supplemented media. The cell internalization of our chemokine receptor-targeting particles increases in accordance with CXCR4 expression in FBS/medium. We demonstrated that CXCL12-decorated nanoparticles do not induce cell migration on their own, but their pre-incubation with THP-1 significantly decreases CXCR4+-cell migration, thereby antagonizing the chemotactic action of CXCL12. The use of biodegradable and immune-compatible chemokine-mimetic nanoparticles to reduce cell migration opens the way to novel antagonists with potential application in cancer treatments and inflammation.
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Affiliation(s)
- Anissa Pisani
- Nanobiointeractions & Nanodiagnostics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (A.P.); (G.C.); (P.P.P.)
- Department of Chemistry and Industrial Chemistry, University of Genova, Via Dodecaneso 31, 16146 Genova, Italy
| | - Roberto Donno
- Laboratory of Polymers and Biomaterials, Istituto Italiano di Tecnologia, 16163 Genova, Italy; (R.D.); (A.G.)
| | - Arianna Gennari
- Laboratory of Polymers and Biomaterials, Istituto Italiano di Tecnologia, 16163 Genova, Italy; (R.D.); (A.G.)
| | - Giulia Cibecchini
- Nanobiointeractions & Nanodiagnostics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (A.P.); (G.C.); (P.P.P.)
- Department of Chemistry and Industrial Chemistry, University of Genova, Via Dodecaneso 31, 16146 Genova, Italy
| | - Federico Catalano
- Electron Microscopy Laboratory, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (F.C.); (R.M.)
| | - Roberto Marotta
- Electron Microscopy Laboratory, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (F.C.); (R.M.)
| | - Pier Paolo Pompa
- Nanobiointeractions & Nanodiagnostics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (A.P.); (G.C.); (P.P.P.)
| | - Nicola Tirelli
- Laboratory of Polymers and Biomaterials, Istituto Italiano di Tecnologia, 16163 Genova, Italy; (R.D.); (A.G.)
- Division of Pharmacy and Optometry, School of Health Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK
- Correspondence: (N.T.); (G.B.); Tel.: +39-010-289-6923 (N.T.); +39-010-289-6519 (G.B.)
| | - Giuseppe Bardi
- Nanobiointeractions & Nanodiagnostics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (A.P.); (G.C.); (P.P.P.)
- Correspondence: (N.T.); (G.B.); Tel.: +39-010-289-6923 (N.T.); +39-010-289-6519 (G.B.)
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5
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Oschwald A, Petry P, Kierdorf K, Erny D. CNS Macrophages and Infant Infections. Front Immunol 2020; 11:2123. [PMID: 33072074 PMCID: PMC7531029 DOI: 10.3389/fimmu.2020.02123] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 08/05/2020] [Indexed: 12/11/2022] Open
Abstract
The central nervous system (CNS) harbors its own immune system composed of microglia in the parenchyma and CNS-associated macrophages (CAMs) in the perivascular space, leptomeninges, dura mater, and choroid plexus. Recent advances in understanding the CNS resident immune cells gave new insights into development, maturation and function of its immune guard. Microglia and CAMs undergo essential steps of differentiation and maturation triggered by environmental factors as well as intrinsic transcriptional programs throughout embryonic and postnatal development. These shaping steps allow the macrophages to adapt to their specific physiological function as first line of defense of the CNS and its interfaces. During infancy, the CNS might be targeted by a plethora of different pathogens which can cause severe tissue damage with potentially long reaching defects. Therefore, an efficient immune response of infant CNS macrophages is required even at these early stages to clear the infections but may also lead to detrimental consequences for the developing CNS. Here, we highlight the recent knowledge of the infant CNS immune system during embryonic and postnatal infections and the consequences for the developing CNS.
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Affiliation(s)
- Alexander Oschwald
- Faculty of Medicine, Institute of Neuropathology, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Philippe Petry
- Faculty of Medicine, Institute of Neuropathology, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Katrin Kierdorf
- Faculty of Medicine, Institute of Neuropathology, University of Freiburg, Freiburg, Germany.,CIBBS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Daniel Erny
- Faculty of Medicine, Institute of Neuropathology, University of Freiburg, Freiburg, Germany
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6
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Cagliani R, Gatto F, Cibecchini G, Marotta R, Catalano F, Sanchez-Moreno P, Pompa PP, Bardi G. CXCL5 Modified Nanoparticle Surface Improves CXCR2 + Cell Selective Internalization. Cells 2019; 9:cells9010056. [PMID: 31878341 PMCID: PMC7016632 DOI: 10.3390/cells9010056] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/17/2019] [Accepted: 12/24/2019] [Indexed: 12/15/2022] Open
Abstract
Driving nanomaterials to specific cell populations is still a major challenge for different biomedical applications. Several strategies to improve cell binding and uptake have been tried thus far by intrinsic material modifications or decoration with active molecules onto their surface. In the present work, we covalently bound the chemokine CXCL5 on fluorescently labeled amino-functionalized SiO2 nanoparticles to precisely targeting CXCR2+ immune cells. We synthesized and precisely characterized the physicochemical features of the modified particles. The presence of CXCL5 on the surface was detected by z-potential variation and CXCL5-specific electron microscopy immunogold labeling. CXCL5-amino SiO2 nanoparticle cell binding and internalization performances were analyzed in CXCR2+ THP-1 cells by flow cytometry and confocal microscopy. We showed improved internalization of the chemokine modified particles in the absence or the presence of serum. This internalization was reduced by cell pre-treatment with free CXCL5. Furthermore, we demonstrated CXCR2+ cell preferential targeting by comparing particle uptake in THP-1 vs. low-CXCR2 expressing HeLa cells. Our results provide the proof of principle that chemokine decorated nanomaterials enhance uptake and allow precise cell subset localization. The possibility to aim at selective chemokine receptor-expressing cells can be beneficial for the diverse pathological conditions involving immune reactions.
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Affiliation(s)
- Roberta Cagliani
- Nanobiointeractions & Nanodiagnostics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (R.C.); (F.G.); (G.C.); (P.S.-M.); (P.P.P.)
- Department of Chemistry and Industrial Chemistry, University of Genova, Via Dodecaneso 31, 16146 Genova, Italy
| | - Francesca Gatto
- Nanobiointeractions & Nanodiagnostics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (R.C.); (F.G.); (G.C.); (P.S.-M.); (P.P.P.)
| | - Giulia Cibecchini
- Nanobiointeractions & Nanodiagnostics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (R.C.); (F.G.); (G.C.); (P.S.-M.); (P.P.P.)
- Department of Chemistry and Industrial Chemistry, University of Genova, Via Dodecaneso 31, 16146 Genova, Italy
| | - Roberto Marotta
- Electron Microscopy Laboratory, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (R.M.); (F.C.)
| | - Federico Catalano
- Electron Microscopy Laboratory, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (R.M.); (F.C.)
| | - Paola Sanchez-Moreno
- Nanobiointeractions & Nanodiagnostics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (R.C.); (F.G.); (G.C.); (P.S.-M.); (P.P.P.)
| | - Pier Paolo Pompa
- Nanobiointeractions & Nanodiagnostics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (R.C.); (F.G.); (G.C.); (P.S.-M.); (P.P.P.)
| | - Giuseppe Bardi
- Nanobiointeractions & Nanodiagnostics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; (R.C.); (F.G.); (G.C.); (P.S.-M.); (P.P.P.)
- Correspondence: ; Tel.: +39-010-2896519
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7
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Smith LK, Kuhn TB, Chen J, Bamburg JR. HIV Associated Neurodegenerative Disorders: A New Perspective on the Role of Lipid Rafts in Gp120-Mediated Neurotoxicity. Curr HIV Res 2019; 16:258-269. [PMID: 30280668 PMCID: PMC6398609 DOI: 10.2174/1570162x16666181003144740] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/17/2018] [Accepted: 09/26/2018] [Indexed: 02/07/2023]
Abstract
The implementation of combination antiretroviral therapy (cART) as the primary means of treatment for HIV infection has achieved a dramatic decline in deaths attributed to AIDS and the reduced incidence of severe forms of HIV-associated neurocognitive disorders (HAND) in infected individuals. Despite these advances, milder forms of HAND persist and prevalence of these forms of neurocognitive impairment are rising with the aging population of HIV infected individuals. HIV enters the CNS early in the pathophysiology establishing persistent infection in resident macrophages and glial cells. These infected cells, in turn, secrete neurotoxic viral proteins, inflammatory cytokines, and small metabolites thought to contribute to neurodegenerative processes. The viral envelope protein gp120 has been identified as a potent neurotoxin affecting neurodegeneration via indirect and direct mechanisms involving interactions with chemokine co-receptors CCR5 and CXCR4. This short review focuses on gp120 neurotropism and associated mechanisms of neurotoxicity linked to chemokine receptors CCR5 and CXCR4 with a new perspective on plasma membrane lipid rafts as an active participant in gp120-mediated neurodegeneration underlying HIV induced CNS pathology.
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Affiliation(s)
- Lisa K Smith
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Thomas B Kuhn
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Jack Chen
- Department of Biology and Wildlife, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - James R Bamburg
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States
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8
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Fulop T, Witkowski JM, Larbi A, Khalil A, Herbein G, Frost EH. Does HIV infection contribute to increased beta-amyloid synthesis and plaque formation leading to neurodegeneration and Alzheimer's disease? J Neurovirol 2019; 25:634-647. [PMID: 30868421 DOI: 10.1007/s13365-019-00732-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/24/2019] [Accepted: 02/01/2019] [Indexed: 10/27/2022]
Abstract
HIV infection in the combination antiretroviral therapy (cART) era has become a chronic disease with a life expectancy almost identical to those free from this infection. Concomitantly, chronic diseases such as neurodegenerative diseases have emerged as serious clinical problems. HIV-induced cognitive changes, although clinically very diverse are collectively called HIV-associated neurocognitive disorder (HAND). HAND, which until the introduction of cART manifested clinically as a subcortical disorder, is now considered primarily cognitive disorder, which makes it similar to diseases like Alzheimer's (AD) and Parkinson's disease (PD). The pathogenesis involves either the direct effects of the virus or the effect of viral proteins such as Tat, Ggp120, and Nef. These proteins are either capable of destroying neurons directly by inducing neurotoxic mediators or by initiating neuroinflammation by microglia and astrocytes. Recently, it has become recognized that HIV infection is associated with increased production of the beta-amyloid peptide (Aβ) which is a characteristic of AD. Moreover, amyloid plaques have also been demonstrated in the brains of patients suffering from HAND. Thus, the question arises whether this production of Aβ indicates that HAND may lead to AD or it is a form of AD or this increase in Aβ production is only a bystander effect. It has also been discovered that APP in HIV and its metabolic product Aβ in AD manifest antiviral innate immune peptide characteristics. This review attempts to bring together studies linking amyloid precursor protein (APP) and Aβ production in HIV infection and their possible impact on the course of HAND and AD. These data indicate that human defense mechanisms in HAND and AD are trying to contain microorganisms by antimicrobial peptides, however by employing different means. Future studies will, no doubt, uncover the relationship between HAND and AD and, hopefully, reveal novel treatment possibilities.
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Affiliation(s)
- Tamas Fulop
- Research Center on Aging, Geriatric Division, Department of Medicine, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, Quebec, J1H 5N4, Canada.
| | - Jacek M Witkowski
- Department of Pathophysiology, Medical University of Gdansk, Gdansk, Poland
| | - Anis Larbi
- Singapore Immunology Network (SIgN), Agency for Science Technology and Research (A*STAR), Immunos Building, Biopolis, Singapore, Singapore.,Department of Biology, Faculty of Science, University Tunis El Manar, Tunis, Tunisia
| | - Abdelouahed Khalil
- Research Center on Aging, Geriatric Division, Department of Medicine, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, Quebec, J1H 5N4, Canada
| | - Georges Herbein
- Department Pathogens & Inflammation-EPILAB, UPRES EA4266, Université of Franche-Comté (UFC), University of Bourgogne France-Comté (UBFC), F-25030, Besançon, France.,Department of Virology, CHRU Besancon, F-25030, Besancon, France
| | - Eric H Frost
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
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9
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Kumar S, Maurya VK, Dandu HR, Bhatt ML, Saxena SK. Global Perspective of Novel Therapeutic Strategies for the Management of NeuroAIDS. Biomol Concepts 2018; 9:33-42. [PMID: 29742062 DOI: 10.1515/bmc-2018-0005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 04/06/2018] [Indexed: 11/15/2022] Open
Abstract
Among Human immunodeficiency virus (HIV) infected individuals, around two-thirds of patients present with neuroAIDS, where HIV-associated neurocognitive disorders (HAND), and HIV-associated dementia (HAD) are the most prevailing neurological complications. The neuropathology of neuroAIDS can be characterized by the presence of HIV infected macrophages and microglia in the brain, with the formation of multinucleated giant cells. Global predominant subtypes of HIV-1 clade B and C infections influence the differential effect of immune and neuronal dysfunctions, leading to clade-specific clinical variation in neuroAIDS patient cohorts. Highly active antiretroviral therapy (HAART) enhances the survival rate among AIDS patients, but due to the inability to cross the Blood-Brain-Barrier (BBB), incidence of neuroAIDS during disease progression may be envisaged. The complex structure of blood-brain-barrier, and poor pharmacokinetic profile coupled with weak bio-distribution of antiretroviral drugs, are the principle barriers for the treatment of neuroAIDS. In the combined antiretroviral therapy (cART) era, the frequency of HAD has decreased; however the incidence of asymptomatic neurocognitive impairment (ANI) and minor neurocognitive disorder (MND) remains consistent. Therefore, several effective novel nanotechnology based therapeutic approaches have been developed to improve the availability of antiretroviral drugs in the brain for the management of neuroAIDS.
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Affiliation(s)
- Swatantra Kumar
- Center for Advanced Research (CFAR)-Stem Cell/Cell Culture Unit, King George's Medical University (KGMU), Lucknow, 226003, India
| | - Vimal K Maurya
- Center for Advanced Research (CFAR)-Stem Cell/Cell Culture Unit, King George's Medical University (KGMU), Lucknow, 226003, India
| | - Himanshu R Dandu
- Center for Advanced Research (CFAR)-Stem Cell/Cell Culture Unit, King George's Medical University (KGMU), Lucknow, 226003, India
| | - Madan Lb Bhatt
- Center for Advanced Research (CFAR)-Stem Cell/Cell Culture Unit, King George's Medical University (KGMU), Lucknow, 226003, India
| | - Shailendra K Saxena
- Center for Advanced Research (CFAR)-Stem Cell/Cell Culture Unit, King George's Medical University (KGMU), Lucknow, 226003, India.,CSIR-Centre for Cellular and Molecular Biology, UppalRoad, Hyderabad, 500007, India
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10
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Nookala AR, Mitra J, Chaudhari NS, Hegde ML, Kumar A. An Overview of Human Immunodeficiency Virus Type 1-Associated Common Neurological Complications: Does Aging Pose a Challenge? J Alzheimers Dis 2018; 60:S169-S193. [PMID: 28800335 DOI: 10.3233/jad-170473] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
With increasing survival of patients infected with human immunodeficiency virus type 1 (HIV-1), the manifestation of heterogeneous neurological complications is also increasing alarmingly in these patients. Currently, more than 30% of about 40 million HIV-1 infected people worldwide develop central nervous system (CNS)-associated dysfunction, including dementia, sensory, and motor neuropathy. Furthermore, the highly effective antiretroviral therapy has been shown to increase the prevalence of mild cognitive functions while reducing other HIV-1-associated neurological complications. On the contrary, the presence of neurological disorder frequently affects the outcome of conventional HIV-1 therapy. Although, both the children and adults suffer from the post-HIV treatment-associated cognitive impairment, adults, especially depending on the age of disease onset, are more prone to CNS dysfunction. Thus, addressing neurological complications in an HIV-1-infected patient is a delicate balance of several factors and requires characterization of the molecular signature of associated CNS disorders involving intricate cross-talk with HIV-1-derived neurotoxins and other cellular factors. In this review, we summarize some of the current data supporting both the direct and indirect mechanisms, including neuro-inflammation and genome instability in association with aging, leading to CNS dysfunction after HIV-1 infection, and discuss the potential strategies addressing the treatment or prevention of HIV-1-mediated neurotoxicity.
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Affiliation(s)
- Anantha Ram Nookala
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, USA
| | - Joy Mitra
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
| | - Nitish S Chaudhari
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, USA
| | - Muralidhar L Hegde
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA.,Weill Cornell Medical College of Cornell University, NY, USA
| | - Anil Kumar
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, USA
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11
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Differentiated Human SH-SY5Y Cells Provide a Reductionist Model of Herpes Simplex Virus 1 Neurotropism. J Virol 2017; 91:JVI.00958-17. [PMID: 28956768 DOI: 10.1128/jvi.00958-17] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 09/19/2017] [Indexed: 12/13/2022] Open
Abstract
Neuron-virus interactions that occur during herpes simplex virus (HSV) infection are not fully understood. Neurons are the site of lifelong latency and are a crucial target for long-term suppressive therapy or viral clearance. A reproducible neuronal model of human origin would facilitate studies of HSV and other neurotropic viruses. Current neuronal models in the herpesvirus field vary widely and have caveats, including incomplete differentiation, nonhuman origins, or the use of dividing cells that have neuropotential but lack neuronal morphology. In this study, we used a robust approach to differentiate human SH-SY5Y neuroblastoma cells over 2.5 weeks, producing a uniform population of mature human neuronal cells. We demonstrate that terminally differentiated SH-SY5Y cells have neuronal morphology and express proteins with subcellular localization indicative of mature neurons. These neuronal cells are able to support a productive HSV-1 infection, with kinetics and overall titers similar to those seen in undifferentiated SH-SY5Y cells and the related SK-N-SH cell line. However, terminally differentiated, neuronal SH-SY5Y cells release significantly less extracellular HSV-1 by 24 h postinfection (hpi), suggesting a unique neuronal response to viral infection. With this model, we are able to distinguish differences in neuronal spread between two strains of HSV-1. We also show expression of the antiviral protein cyclic GMP-AMP synthase (cGAS) in neuronal SH-SY5Y cells, which is the first demonstration of the presence of this protein in nonepithelial cells. These data provide a model for studying neuron-virus interactions at the single-cell level as well as via bulk biochemistry and will be advantageous for the study of neurotropic viruses in vitroIMPORTANCE Herpes simplex virus (HSV) affects millions of people worldwide, causing painful oral and genital lesions, in addition to a multitude of more severe symptoms such as eye disease, neonatal infection, and, in rare cases, encephalitis. Presently, there is no cure available to treat those infected or prevent future transmission. Due to the ability of HSV to cause a persistent, lifelong infection in the peripheral nervous system, the virus remains within the host for life. To better understand the basis of virus-neuron interactions that allow HSV to persist within the host peripheral nervous system, improved neuronal models are required. Here we describe a cost-effective and scalable human neuronal model system that can be used to study many neurotropic viruses, such as HSV, Zika virus, dengue virus, and rabies virus.
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Tsou LK, Huang YH, Song JS, Ke YY, Huang JK, Shia KS. Harnessing CXCR4 antagonists in stem cell mobilization, HIV infection, ischemic diseases, and oncology. Med Res Rev 2017; 38:1188-1234. [PMID: 28768055 DOI: 10.1002/med.21464] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 07/13/2017] [Accepted: 07/16/2017] [Indexed: 12/12/2022]
Abstract
CXCR4 antagonists (e.g., PlerixaforTM ) have been successfully validated as stem cell mobilizers for peripheral blood stem cell transplantation. Applications of the CXCR4 antagonists have heralded the era of cell-based therapy and opened a potential therapeutic horizon for many unmet medical needs such as kidney injury, ischemic stroke, cancer, and myocardial infarction. In this review, we first introduce the central role of CXCR4 in diverse cellular signaling pathways and discuss its involvement in several disease progressions. We then highlight the molecular design and optimization strategies for targeting CXCR4 from a large number of case studies, concluding that polyamines are the preferred CXCR4-binding ligands compared to other structural options, presumably by mimicking the highly positively charged natural ligand CXCL12. These results could be further justified with computer-aided docking into the CXCR4 crystal structure wherein both major and minor subpockets of the binding cavity are considered functionally important. Finally, from the clinical point of view, CXCR4 antagonists could mobilize hematopoietic stem/progenitor cells with long-term repopulating capacity to the peripheral blood, promising to replace surgically obtained bone marrow cells as a preferred source for stem cell transplantation.
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Affiliation(s)
- Lun Kelvin Tsou
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli County, Taiwan, ROC
| | | | - Jen-Shin Song
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli County, Taiwan, ROC
| | - Yi-Yu Ke
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli County, Taiwan, ROC
| | - Jing-Kai Huang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli County, Taiwan, ROC
| | - Kak-Shan Shia
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli County, Taiwan, ROC
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Macrophages and Phospholipases at the Intersection between Inflammation and the Pathogenesis of HIV-1 Infection. Int J Mol Sci 2017; 18:ijms18071390. [PMID: 28661459 PMCID: PMC5535883 DOI: 10.3390/ijms18071390] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 06/22/2017] [Accepted: 06/26/2017] [Indexed: 12/12/2022] Open
Abstract
Persistent low grade immune activation and chronic inflammation are nowadays considered main driving forces of the progressive immunologic failure in effective antiretroviral therapy treated HIV-1 infected individuals. Among the factors contributing to this phenomenon, microbial translocation has emerged as a key driver of persistent immune activation. Indeed, the rapid depletion of gastrointestinal CD4+ T lymphocytes occurring during the early phases of infection leads to a deterioration of the gut epithelium followed by the translocation of microbial products into the systemic circulation and the subsequent activation of innate immunity. In this context, monocytes/macrophages are increasingly recognized as an important source of inflammation, linked to HIV-1 disease progression and to non-AIDS complications, such as cardiovascular disease and neurocognitive decline, which are currently main challenges in treated patients. Lipid signaling plays a central role in modulating monocyte/macrophage activation, immune functions and inflammatory responses. Phospholipase-mediated phospholipid hydrolysis leads to the production of lipid mediators or second messengers that affect signal transduction, thus regulating a variety of physiologic and pathophysiologic processes. In this review, we discuss the contribution of phospholipases to monocyte/macrophage activation in the context of HIV-1 infection, focusing on their involvement in virus-associated chronic inflammation and co-morbidities.
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Expression of CHRFAM7A and CHRNA7 in neuronal cells and postmortem brain of HIV-infected patients: considerations for HIV-associated neurocognitive disorder. J Neurovirol 2015; 22:327-35. [PMID: 26567012 DOI: 10.1007/s13365-015-0401-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 10/13/2015] [Accepted: 10/27/2015] [Indexed: 10/22/2022]
Abstract
Despite the recent advances in antiretroviral therapy, human immunodeficiency virus type 1 (HIV-1) remains a global health threat. HIV-1 affects the central nervous system by releasing viral proteins that trigger neuronal death and neuroinflammation, and promotes alterations known as HIV-associated neurocognitive disorders (HAND). This disorder is not fully understood, and no specific treatments are available. Recently, we demonstrated that the HIV-1 envelope protein gp120IIIB induces a functional upregulation of the α7-nicotinic acetylcholine receptor (α7) in neuronal cells. Furthermore, this upregulation promotes cell death that can be abrogated with receptor antagonists, suggesting that α7 may play an important role in the development of HAND. The partial duplication of the gene coding for the α7, known as CHRFAM7A, negatively regulates α7 expression but its role in HIV infection has not been studied. Hence, we studied both CHRNA7 and CHRFAM7A regulation patterns in various gp120IIIB in vitro conditions. In addition, we measured CHRNA7 and CHRFAM7A expression levels in postmortem brain samples from patients suffering from different stages of HAND. Our results demonstrate the induction of CHRNA7 expression accompanied by a significant downregulation of CHRFAM7A in neuronal cells when exposed to pathophysiological concentrations of gp120IIIB. Our results suggest a dysregulation of CHRFAM7A and CHRNA7 expressions in the basal ganglia from postmortem brain samples of HIV+ subjects and expand the current knowledge about the consequences of HIV infection in the brain.
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Induction of Interleukin-1β by Human Immunodeficiency Virus-1 Viral Proteins Leads to Increased Levels of Neuronal Ferritin Heavy Chain, Synaptic Injury, and Deficits in Flexible Attention. J Neurosci 2015. [PMID: 26203149 DOI: 10.1523/jneurosci.4403-14.2015] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Synaptodendritic pruning and alterations in neurotransmission are the main underlying causes of HIV-associated neurocognitive disorders (HAND). Our studies in humans and nonhuman primates indicated that the protein ferritin heavy chain (FHC) is a critical player in neuronal changes and ensuing cognitive deficit observed in these patients. Here we focus on the effect of HIV proteins and inflammatory cytokines implicated in HAND on neuronal FHC levels, dendritic changes, and neurocognitive behavior. In two well characterized models of HAND (HIV transgenic and gp120-treated rats), we report reductions in spine density and dendritic branches in prefrontal cortex pyramidal neurons compared with age-matched controls. FHC brain levels are elevated in these animals, which also show deficits in reversal learning. Moreover, IL-1β, TNF-α, and HIV gp120 upregulate FHC in rat cortical neurons. However, although the inflammatory cytokines directly altered neuronal FHC, gp120 only caused significant FHC upregulation in neuronal/glial cocultures, suggesting that glia are necessary for sustained elevation of neuronal FHC by the viral protein. Although the envelope protein induced secretion of IL-1β and TNF-α in cocultures, TNF-α blockade did not affect gp120-mediated induction of FHC. Conversely, studies with an IL-1β neutralizing antibody or specific IL-1 receptor antagonist revealed the primary involvement of IL-1β in gp120-induced FHC changes. Furthermore, silencing of neuronal FHC abrogates the effect of gp120 on spines, and spine density correlates negatively with FHC levels or cognitive deficit. These results demonstrate that viral and host components of HIV infection increase brain expression of FHC, leading to cellular and functional changes, and point to IL-1β-targeted strategies for prevention of these alterations. Significance statement: This work demonstrates the key role of the cytokine IL-1β in the regulation of a novel intracellular mediator [i.e., the protein ferritin heavy chain (FHC)] of HIV-induced dendritic damage and the resulting neurocognitive impairment. This is also the first study that systematically investigates dendritic damage in layer II/III prefrontal cortex neurons of two different non-infectious models of HIV-associated neurocognitive disorders (HAND) and reveals a precise correlation of these structural changes with specific biochemical and functional alterations also reported in HIV patients. Overall, these data suggest that targeting the IL-1β-dependent FHC increase may represent a valid strategy for neuroprotective adjuvant therapies in HAND.
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Pandhare J, Dash S, Jones B, Villalta F, Dash C. A Novel Role of Proline Oxidase in HIV-1 Envelope Glycoprotein-induced Neuronal Autophagy. J Biol Chem 2015; 290:25439-51. [PMID: 26330555 DOI: 10.1074/jbc.m115.652776] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Indexed: 12/17/2022] Open
Abstract
Proline oxidase (POX) catalytically converts proline to pyrroline-5-carboxylate. This catabolic conversion generates reactive oxygen species (ROS) that triggers cellular signaling cascades including autophagy and apoptosis. This study for the first time demonstrates a role of POX in HIV-1 envelope glycoprotein (gp120)-induced neuronal autophagy. HIV-1 gp120 is a neurotoxic factor and is involved in HIV-1-associated neurological disorders. However, the mechanism of gp120-mediated neurotoxicity remains unclear. Using SH-SY5Y neuroblastoma cells as a model, this study demonstrates that gp120 treatment induced POX expression and catalytic activity. Concurrently, gp120 also increased intracellular ROS levels. However, increased ROS had a minimal effect on neuronal apoptosis. Further investigation indicated that the immediate cellular response to increased ROS paralleled with induction of autophagy markers, beclin-1 and LC3-II. These data lead to the hypothesis that neuronal autophagy is activated as a cellular protective response to the toxic effects of gp120. A direct and functional role of POX in gp120-mediated neuronal autophagy was examined by inhibition and overexpression studies. Inhibition of POX activity by a competitive inhibitor "dehydroproline" decreased ROS levels concomitant with reduced neuronal autophagy. Conversely, overexpression of POX in neuronal cells increased ROS levels and activated ROS-dependent autophagy. Mechanistic studies suggest that gp120 induces POX by targeting p53. Luciferase reporter assays confirm that p53 drives POX transcription. Furthermore, data demonstrate that gp120 induces p53 via binding to the CXCR4 co-receptor. Collectively, these results demonstrate a novel role of POX as a stress response metabolic regulator in HIV-1 gp120-associated neuronal autophagy.
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Affiliation(s)
- Jui Pandhare
- From the Center for AIDS Health Disparities Research, School of Graduate Studies and Research, Department of Microbiology and Immunology, and
| | - Sabyasachi Dash
- From the Center for AIDS Health Disparities Research, School of Graduate Studies and Research
| | - Bobby Jones
- From the Center for AIDS Health Disparities Research, School of Graduate Studies and Research, Department of Microbiology and Immunology, and
| | - Fernando Villalta
- From the Center for AIDS Health Disparities Research, School of Graduate Studies and Research, Department of Microbiology and Immunology, and
| | - Chandravanu Dash
- From the Center for AIDS Health Disparities Research, School of Graduate Studies and Research, Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, Tennessee 37208
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Abstract
In the era of combined antiretroviral therapy (cART), HIV-associated neurocognitive disorders (HAND) account for 40 to 56% of all HIV+ cases. During the acute stage of HIV-1 infection (<6 months), the virus invades and replicates within the central nervous system (CNS). Compared to peripheral tissues, the local CNS cell population expresses distinct levels of chemokine receptors, which levels exert selective pressure on the invading virus. HIV-1 envelope (env) sequences recovered from the brains and cerebrospinal fluid (CSF) of neurocognitively impaired HIV+ subjects often display higher nucleotide variability as compared to non-impaired HIV+ subjects. Specifically, env evolution provides HIV-1 with the strategies to evade host immune response, to reduce chemokine receptor dependence, to increase co-receptor binding efficiency, and to potentiate neurotoxicity. The evolution of env within the CNS leads to changes that may result in the emergence of novel isolates with neurotoxic and neurovirulent features. However, whether specific factors of HIV-1 evolution lead to the emergence of neurovirulent and neurotropic isolates remains ill-defined. HIV-1 env evolution is an ongoing phenomenon that occurs independently of neurological and neurocognitive disease severity; thus HIV env evolution may play a pivotal and reciprocal role in the etiology of HAND. Despite the use of cART, the reactivation of latent viral reservoirs represents a clinical challenge because of the replenishment of the viral pool that may subsequently lead to persistent infection. Therefore, gaining a more complete understanding of how HIV-1 env evolves over the course of the disease should be considered for the development of future therapies aimed at controlling CNS burden, diminishing persistent viremia, and eradicating viral reservoirs. Here we review the current literature on the role of HIV-1 env evolution in the setting of HAND disease progression and on the impact of cART on the dynamics of viral evolution.
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Affiliation(s)
- Fabián J Vázquez-Santiago
- Department of Basic Sciences, Ponce Health Sciences University- School of Medicine / Ponce Research Institute, Ponce, PR 00716, USA
| | - Vanessa Rivera-Amill
- Department of Basic Sciences, Ponce Health Sciences University- School of Medicine / Ponce Research Institute, Ponce, PR 00716, USA
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Vigorito M, Connaghan KP, Chang SL. The HIV-1 transgenic rat model of neuroHIV. Brain Behav Immun 2015; 48:336-49. [PMID: 25733103 PMCID: PMC4753047 DOI: 10.1016/j.bbi.2015.02.020] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 02/16/2015] [Accepted: 02/20/2015] [Indexed: 01/28/2023] Open
Abstract
Despite the ability of current combination anti-retroviral therapy (cART) to limit the progression of HIV-1 to AIDS, HIV-positive individuals continue to experience neuroHIV in the form of HIV-associated neurological disorders (HAND), which can range from subtle to substantial neurocognitive impairment. NeuroHIV may also influence substance use, abuse, and dependence in HIV-positive individuals. Because of the nature of the virus, variables such as mental health co-morbidities make it difficult to study the interaction between HIV and substance abuse in human populations. Several rodent models have been developed in an attempt to study the transmission and pathogenesis of the HIV-1 virus. The HIV-1 transgenic (HIV-1Tg) rat is a reliable model of neuroHIV because it mimics the condition of HIV-infected patients on cART. Research using this model supports the hypothesis that the presence of HIV-1 viral proteins in the central nervous system increases the sensitivity and susceptibility of HIV-positive individuals to substance abuse.
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Affiliation(s)
- Michael Vigorito
- Institute of NeuroImmune Pharmacology and Department of Biological Sciences, Seton Hall University, South Orange, NJ, USA
| | - Kaitlyn P Connaghan
- Institute of NeuroImmune Pharmacology and Department of Biological Sciences, Seton Hall University, South Orange, NJ, USA
| | - Sulie L Chang
- Institute of NeuroImmune Pharmacology and Department of Biological Sciences, Seton Hall University, South Orange, NJ, USA.
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Rao VR, Ruiz AP, Prasad VR. Viral and cellular factors underlying neuropathogenesis in HIV associated neurocognitive disorders (HAND). AIDS Res Ther 2014; 11:13. [PMID: 24894206 PMCID: PMC4043700 DOI: 10.1186/1742-6405-11-13] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 05/08/2014] [Indexed: 11/11/2022] Open
Abstract
As the HIV-1 epidemic enters its fourth decade, HIV-1 associated neurological disorders (HAND) continue to be a major concern in the infected population, despite the widespread use of anti-retroviral therapy. Advancing age and increased life expectancy of the HIV-1 infected population have been shown to increase the risk of cognitive dysfunction. Over the past 10 years, there has been a significant progress in our understanding of the mechanisms and the risk factors involved in the development of HAND. Key events that lead up to neuronal damage in HIV-1 infected individuals can be categorized based on the interaction of HIV-1 with the various cell types, including but not limited to macrophages, brain endothelial cells, microglia, astrocytes and the neurons. This review attempts to decipher these interactions, beginning with HIV-1 infection of macrophages and ultimately resulting in the release of neurotoxic viral and host products. These include: interaction with endothelial cells, resulting in the impairment of the blood brain barrier; interaction with the astrocytes, leading to metabolic and neurotransmitter imbalance; interactions with resident immune cells in the brain, leading to release of toxic cytokines and chemokines. We also review the mechanisms underlying neuronal damage caused by the factors mentioned above. We have attempted to bring together recent findings in these areas to help appreciate the viral and host factors that bring about neurological dysfunction. In addition, we review host factors and viral genotypic differences that affect phenotypic pathological outcomes, as well as recent advances in treatment options to specifically address the neurotoxic mechanisms in play.
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Clift IC, Bamidele AO, Rodriguez-Ramirez C, Kremer KN, Hedin KE. β-Arrestin1 and distinct CXCR4 structures are required for stromal derived factor-1 to downregulate CXCR4 cell-surface levels in neuroblastoma. Mol Pharmacol 2014; 85:542-52. [PMID: 24452472 DOI: 10.1124/mol.113.089714] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
CXC chemokine receptor 4 (CXCR4) is a G protein-coupled receptor (GPCR) located on the cell surface that signals upon binding the chemokine stromal derived factor-1 (SDF-1; also called CXCL 12). CXCR4 promotes neuroblastoma proliferation and chemotaxis. CXCR4 expression negatively correlates with prognosis and drives neuroblastoma growth and metastasis in mouse models. All functions of CXCR4 require its expression on the cell surface, yet the molecular mechanisms that regulate CXCR4 cell-surface levels in neuroblastoma are poorly understood. We characterized CXCR4 cell-surface regulation in the related SH-SY5Y and SK-N-SH human neuroblastoma cell lines. SDF-1 treatment caused rapid down-modulation of CXCR4 in SH-SY5Y cells. Pharmacologic activation of protein kinase C similarly reduced CXCR4, but via a distinct mechanism. Analysis of CXCR4 mutants delineated two CXCR4 regions required for SDF-1 treatment to decrease cell-surface CXCR4 in neuroblastoma cells: the isoleucine-leucine motif at residues 328 and 329 and residues 343-352. In contrast, and unlike CXCR4 regulation in other cell types, serines 324, 325, 338, and 339 were not required. Arrestin proteins can bind and regulate GPCR cell-surface expression, often functioning together with kinases such as G protein-coupled receptor kinase 2 (GRK2). Using SK-N-SH cells which are naturally deficient in β-arrestin1, we showed that β-arrestin1 is required for the CXCR4 343-352 region to modulate CXCR4 cell-surface expression following treatment with SDF-1. Moreover, GRK2 overexpression enhanced CXCR4 internalization, via a mechanism requiring both β-arrestin1 expression and the 343-352 region. Together, these results characterize CXCR4 structural domains and β-arrestin1 as critical regulators of CXCR4 cell-surface expression in neuroblastoma. β-Arrestin1 levels may therefore influence the CXCR4-driven metastasis of neuroblastoma as well as prognosis.
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Affiliation(s)
- Ian C Clift
- Neurobiology of Disease (I.C.C.), Molecular Pharmacology and Experimental Therapeutics (A.O.B.), and Department of Immunology (C.R.-R., K.N.K., K.E.H.), Mayo Clinic College of Medicine, Mayo Graduate School, Mayo Clinic, Rochester, Minnesota
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Nash B, Meucci O. Functions of the chemokine receptor CXCR4 in the central nervous system and its regulation by μ-opioid receptors. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2014; 118:105-28. [PMID: 25175863 PMCID: PMC4369781 DOI: 10.1016/b978-0-12-801284-0.00005-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Activation of the G protein-coupled receptor CXCR4 by its chemokine ligand CXCL12 regulates a number of physiopathological functions in the central nervous system, during development as well as later in life. In addition to the more classical roles of the CXCL12/CXCR4 axis in the recruitment of immune cells or migration and proliferation of neural precursor cells, recent studies suggest that CXCR4 signaling also modulates synaptic function and neuronal survival in the mature brain, through direct and indirect effects on neurons and glia. These effects, which include regulation of glutamate receptors and uptake, and of dendritic spine density, can significantly alter the ability of neurons to face excitotoxic insults. Therefore, they are particularly relevant to neurodegenerative diseases featuring alterations of glutamate neurotransmission, such as HIV-associated neurocognitive disorders. Importantly, CXCR4 signaling can be dysregulated by HIV viral proteins, host HIV-induced factors, and opioids. Potential mechanisms of opioid regulation of CXCR4 include heterologous desensitization, transcriptional regulation and changes in receptor expression levels, opioid-chemokine receptor dimer or heteromer formation, and the newly described modulation by the protein ferritin heavy chain-all leading to inhibition of CXCR4 signaling. After reviewing major effects of chemokines and opioids in the CNS, this chapter discusses chemokine-opioid interactions in neuronal and immune cells, focusing on their potential contribution to HIV-associated neurocognitive disorders.
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Affiliation(s)
- Bradley Nash
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Olimpia Meucci
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.
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22
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Choi WT, Duggineni S, Xu Y, Huang Z, An J. Drug discovery research targeting the CXC chemokine receptor 4 (CXCR4). J Med Chem 2011; 55:977-94. [PMID: 22085380 DOI: 10.1021/jm200568c] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Won-Tak Choi
- Department of Pathology, The University of Washington School of Medicine, Seattle, Washington 98195, United States
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Ballester LY, Capó-Vélez CM, García-Beltrán WF, Ramos FM, Vázquez-Rosa E, Ríos R, Mercado JR, Meléndez RI, Lasalde-Dominicci JA. Up-regulation of the neuronal nicotinic receptor α7 by HIV glycoprotein 120: potential implications for HIV-associated neurocognitive disorder. J Biol Chem 2011; 287:3079-86. [PMID: 22084248 DOI: 10.1074/jbc.m111.262543] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Approximately 30-50% of the >30 million HIV-infected subjects develop neurological complications ranging from mild symptoms to dementia. HIV does not infect neurons, and the molecular mechanisms behind HIV-associated neurocognitive decline are not understood. There are several hypotheses to explain the development of dementia in HIV(+) individuals, including neuroinflammation mediated by infected microglia and neuronal toxicity by HIV proteins. A key protein associated with the neurological complications of HIV, gp120, forms part of the viral envelope and can be found in the CSF of infected individuals. HIV-1-gp120 interacts with several receptors including CD4, CCR5, CXCR4, and nicotinic acetylcholine receptors (nAChRs). However, the role of nAChRs in HIV-associated neurocognitive disorder has not been investigated. We studied the effects of gp120(IIIB) on the expression and function of the nicotinic receptor α7 (α7-nAChR). Our results show that gp120, through activation of the CXCR4 chemokine receptor, induces a functional up-regulation of α7-nAChRs. Because α7-nAChRs have a high permeability to Ca(2+), we performed TUNEL staining to investigate the effects of receptor up-regulation on cell viability. Our data revealed an increase in cell death, which was blocked by the selective antagonist α-bungarotoxin. The in vitro data are supported by RT-PCR and Western blot analysis, confirming a remarkable up-regulation of the α7-nAChR in gp120-transgenic mice brains. Specifically, α7-nAChR up-regulation is observed in mouse striatum, a region severely affected in HIV(+) patients. In summary, CXCR4 activation induces up-regulation of α7-nAChR, causing cell death, suggesting that α7-nAChR is a previously unrecognized contributor to the neurotoxicity associated with HIV infection.
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Affiliation(s)
- Leomar Y Ballester
- Department of Biology, University of Puerto Rico, Río Piedras Campus, San Juan, Puerto Rico
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Shimizu S, Brown M, Sengupta R, Penfold ME, Meucci O. CXCR7 protein expression in human adult brain and differentiated neurons. PLoS One 2011; 6:e20680. [PMID: 21655198 PMCID: PMC3105114 DOI: 10.1371/journal.pone.0020680] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 05/07/2011] [Indexed: 01/22/2023] Open
Abstract
Background CXCR7 and CXCR4 are receptors for the chemokine CXCL12, which is involved in
essential functions of the immune and nervous systems. Although
CXCR7 transcripts are widely expressed throughout the
central nervous system, little is known about its protein distribution and
function in the adult brain. To evaluate its potential involvement in
CXCL12/CXCR4 signaling in differentiated neurons, we studied CXCR7 protein
expression in human brain and cultured neurons. Methodology/Principal Findings Immunohistochemistry and RT-PCR analyses of cortex and hippocampus from
control and HIV-positive subjects provided the first evidence of CXCR7
protein expression in human adult neurons, under normal and pathological
conditions. Furthermore, confocal microscopy and binding assays in cultured
neurons show that CXCR7 protein is mainly located into cytoplasm, while
little to no protein expression is found on neuronal plasma membrane.
Interestingly, specific CXCR7 ligands that inhibit CXCL12 binding to CXCR7
do not alter CXCR4-activated survival signaling (pERK/pAkt) in rat cortical
neurons. Neuronal CXCR7 co-localizes to some extent with the endoplasmic
reticulum marker ERp29, but not with early/late endosome markers.
Additionally, large areas of overlap are detected in the intracellular
pattern of CXCR7 and CXCR4 expression. Conclusions/Significance Overall, these results implicate CXCR4 as the main CXCL12 signaling receptor
on the surface of differentiated neurons and suggest that CXCR7 may interact
with CXCR4 at the intracellular level, possibly affecting CXCR4 trafficking
and/or coupling to other proteins.
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Affiliation(s)
- Saori Shimizu
- Department of Pharmacology and Physiology, Drexel University College of
Medicine, Philadelphia, Pennsylvania, United States of America
| | - Michael Brown
- Department of Pharmacology and Physiology, Drexel University College of
Medicine, Philadelphia, Pennsylvania, United States of America
| | - Rajarshi Sengupta
- Department of Pharmacology and Physiology, Drexel University College of
Medicine, Philadelphia, Pennsylvania, United States of America
| | - Mark E. Penfold
- ChemoCentryx, Mountain View, California, United States of
America
| | - Olimpia Meucci
- Department of Pharmacology and Physiology, Drexel University College of
Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Microbiology and Immunology, Drexel University College of
Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Protection against HIV-envelope-induced neuronal cell destruction by HIV attachment inhibitors. Arch Virol 2010; 155:777-81. [PMID: 20300783 DOI: 10.1007/s00705-010-0644-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 02/10/2010] [Indexed: 10/19/2022]
Abstract
We demonstrate that HIV attachment inhibitors (AIs) prevent HIV envelope-induced destruction of two neuronal cell lines (SH-SY5Y and BE(2)-M17) at low nanomolar concentrations. The fusion inhibitor enfuvirtide and the CCR5 inhibitors UK427,857 and TAK779 do not display protection activity, suggesting the involvement of Env/cell interaction site(s) distinct from the sites involved in the viral entry process. We surmise that by inducing conformation changes in the envelope, AIs likely obstruct novel interactions with a neuronal cell factor(s) required for induction of apoptosis. This antiretroviral class may therefore have the potential to inhibit HIV-induced neuron damage, thereby curtailing the increasing incidence of HIV-associated cognitive impairment.
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Cook A, Hippensteel R, Shimizu S, Nicolai J, Fatatis A, Meucci O. Interactions between chemokines: regulation of fractalkine/CX3CL1 homeostasis by SDF/CXCL12 in cortical neurons. J Biol Chem 2010; 285:10563-71. [PMID: 20124406 DOI: 10.1074/jbc.m109.035477] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The soluble form of the chemokine fractalkine/CX(3)CL1 regulates microglia activation in the central nervous system (CNS), ultimately affecting neuronal survival. This study aims to determine whether CXCL12, another chemokine constitutively expressed in the CNS (known as stromal cell-derived factor 1; SDF-1), regulates cleavage of fractalkine from neurons. To this end, ELISA was used to measure protein levels of soluble fractalkine in the medium of rat neuronal cultures exposed to SDF-1. Gene arrays, quantitative RT-PCR, and Western blot were used to measure overall fractalkine expression in neurons. The data show that the rate of fractalkine shedding in healthy cultures positively correlates with in vitro differentiation and survival. In analogy to non-neuronal cells, metalloproteinases (ADAM10/17) are involved in cleavage of neuronal fractalkine as indicated by studies with pharmacologic inhibitors. Moreover, treatment of the neuronal cultures with SDF-1 stimulates expression of the inducible metalloproteinase ADAM17 and increases soluble fractalkine content in culture medium. The effect of SDF-1 is blocked by an inhibitor of both ADAM10 and -17, but only partially affected by a more specific inhibitor of ADAM10. In addition, SDF-1 also up-regulates expression of the fractalkine gene. Conversely, exposure of neurons to an excitotoxic stimulus (i.e. NMDA) inhibits alpha-secretase activity and markedly diminishes soluble fractalkine levels, leading to cell death. These results, along with previous findings on the neuroprotective role of both SDF-1 and fractalkine, suggest that this novel interaction between the two chemokines may contribute to in vivo regulation of neuronal survival by modulating microglial neurotoxic properties.
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Affiliation(s)
- Anna Cook
- Departments of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
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Morphine increases brain levels of ferritin heavy chain leading to inhibition of CXCR4-mediated survival signaling in neurons. J Neurosci 2009; 29:2534-44. [PMID: 19244528 DOI: 10.1523/jneurosci.5865-08.2009] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
This study focuses on the effect of mu-opioid receptor agonists on CXCR4 signaling in neurons and the mechanisms involved in regulation of neuronal CXCR4 by opiates. The data show that CXCR4 is negatively modulated by long-term morphine treatments both in vitro and in vivo; CXCR4 inhibition is caused by direct stimulation of mu-opioid receptors in neurons, leading to alterations of ligand-induced CXCR4 phosphorylation and upregulation of protein ferritin heavy chain (FHC), a negative intracellular regulator of CXCR4. Reduced coupling of CXCR4 to G-proteins was found in the brain of morphine-treated rats, primarily cortex and hippocampus. CXCR4-induced G alpha(i)/G betagamma activities were suppressed after 24 h treatment of cortical neurons with morphine or the selective mu-opioid agonist DAMGO (D-Ala2-N-Me-Phe(4)-glycol(5)-enkephalin), as shown by analysis of downstream targets of CXCR4 (i.e., cAMP, Akt, and ERK1/2). These agonists also prevented CXCL12-induced phosphorylation of CXCR4, indicating a deficit of CXCR4 activation in these conditions. Indeed, morphine (or DAMGO) inhibited prosurvival signaling in neurons. These effects are not attributable to a reduction in CXCR4 expression or surface levels but rather to upregulation of FHC by opioids. The crucial role of FHC in inhibition of neuronal CXCR4 was confirmed by in vitro and in vivo RNA interference studies. Overall, these findings suggest that opiates interfere with normal CXCR4 function in the brain. By this mechanism, opiates could reduce the neuroprotective functions of CXCR4 and exacerbate neuropathology in opiate abusers who are affected by neuroinflammatory/infectious disorders, including neuroAIDS.
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Pluronic-coated carbon nanotubes do not induce degeneration of cortical neurons in vivo and in vitro. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2009; 5:96-104. [DOI: 10.1016/j.nano.2008.06.008] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Revised: 06/26/2008] [Accepted: 06/27/2008] [Indexed: 11/21/2022]
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29
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The chemokine CXCL12 promotes survival of postmitotic neurons by regulating Rb protein. Cell Death Differ 2008; 15:1663-72. [PMID: 18583990 DOI: 10.1038/cdd.2008.95] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Postmitotic neurons need to keep their cell cycle under control to survive and maintain a differentiated state. This study aims to test the hypothesis that the chemokine CXCL12 regulates neuronal survival and differentiation by promoting Rb function, as suggested by previous studies showing that CXCL12 protects neurons from apoptosis induced by Rb loss. To this end, the effect of CXCL12 on Rb expression and transcriptional activity and the role of Rb in CXCL12-induced neuronal survival were studied. CXCL12 increases Rb protein and RNA levels in rat cortical neurons. The chemokine also stimulates an exogenous Rb promoter expressed in these neurons and counteracts the inhibition of the Rb promoter induced by E2F1 overexpression. Furthermore CXCL12 stimulates Rb activity as a transcription repressor. The effects of CXCL12 are mediated by its specific receptor CXCR4, and do not require the presence of glia. Finally, shRNA studies show that Rb expression is crucial to the neuroprotective activity of CXCL12 as indicated by NMDA-neurotoxicity assays. These findings suggest that proper CXCR4 stimulation in the mature CNS can prevent impairment of the Rb-E2F pathway and support neuronal survival. This is important to maintain CNS integrity in physiological conditions and prevent neuronal injury and loss typical of many neurodegenerative and neuroinflammatory conditions.
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Ahmed F, Tessarollo L, Thiele C, Mocchetti I. Brain-derived neurotrophic factor modulates expression of chemokine receptors in the brain. Brain Res 2008; 1227:1-11. [PMID: 18588860 DOI: 10.1016/j.brainres.2008.05.086] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 05/14/2008] [Accepted: 05/24/2008] [Indexed: 10/21/2022]
Abstract
Chemokine receptors, and in particular CXCR4 and CCR5 play a key role in the neuropathogenesis of Human Immunodeficiency Virus-1 (HIV)4 associated dementia (HAD). Thus, new insight into the expression of CXCR4 in the central nervous system may help develop therapeutic compounds against HAD. Brain-derived neurotrophic factor (BDNF) is neuroprotective in vitro against two strains of the HIV envelope protein gp120 that binds to CXCR4 or CCR5. Therefore, we examined whether BDNF modulates chemokine receptor expression in vivo. The content of CXCR4 mRNA and proteins was determined in the cerebral cortex and hippocampus of 6-month-old BDNF heterozygous mice and wild type littermates by using polymerase chain reaction and immunohistochemistry, respectively. BDNF heterozygous mice exhibited an increase in CXCR4 mRNA compared to wild type. Histological analyses revealed an up-regulation of CXCR4 immunoreactivity mainly in neurons. Most of these neurons were positive for TrkB, the BDNF receptor with a tyrosine kinase activity. Increases in CXCR4 mRNA levels were observed in 18-month-old BDNF heterozygous mice but not in 7-day-old mice, suggesting that the modulatory role of BDNF occurs only in mature animals. To determine whether BDNF affects also CXCR4 internalization, SH-SY5Y neuroblastoma cells were exposed to BDNF and cell surface CXCR4 levels were measured at various times. BDNF induced CXCR4 internalization within minutes. Lastly, BDNF heterozygous mice showed higher levels of CCR5 and CXCR3 mRNA than wild type in the cerebral cortex, hippocampus and striatum. Our data indicate that BDNF may modulate the availability of chemokine receptors implicated in HIV infection.
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Affiliation(s)
- Farid Ahmed
- Department of Neuroscience, Georgetown University Medical Center, Washington DC, USA
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31
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Li M, Ransohoff RM. Multiple roles of chemokine CXCL12 in the central nervous system: a migration from immunology to neurobiology. Prog Neurobiol 2008; 84:116-31. [PMID: 18177992 PMCID: PMC2324067 DOI: 10.1016/j.pneurobio.2007.11.003] [Citation(s) in RCA: 266] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Revised: 10/15/2007] [Accepted: 11/09/2007] [Indexed: 10/22/2022]
Abstract
Chemotactic cytokines (chemokines) have been traditionally defined as small (10-14kDa) secreted leukocyte chemoattractants. However, chemokines and their cognate receptors are constitutively expressed in the central nervous system (CNS) where immune activities are under stringent control. Why and how the CNS uses the chemokine system to carry out its complex physiological functions has intrigued neurobiologists. Here, we focus on chemokine CXCL12 and its receptor CXCR4 that have been widely characterized in peripheral tissues and delineate their main functions in the CNS. Extensive evidence supports CXCL12 as a key regulator for early development of the CNS. CXCR4 signaling is required for the migration of neuronal precursors, axon guidance/pathfinding and maintenance of neural progenitor cells (NPCs). In the mature CNS, CXCL12 modulates neurotransmission, neurotoxicity and neuroglial interactions. Thus, chemokines represent an inherent system that helps establish and maintain CNS homeostasis. In addition, growing evidence implicates altered expression of CXCL12 and CXCR4 in the pathogenesis of CNS disorders such as HIV-associated encephalopathy, brain tumor, stroke and multiple sclerosis (MS), making them the plausible targets for future pharmacological intervention.
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Affiliation(s)
- Meizhang Li
- Neuroinflammation Research Center, Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Mail Code NC30, 9500 Euclid Avenue, Cleveland, Ohio 44195, USA
| | - Richard M. Ransohoff
- Neuroinflammation Research Center, Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Mail Code NC30, 9500 Euclid Avenue, Cleveland, Ohio 44195, USA
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Takano Y, Shimokado K, Hata Y, Yoshida M. HIV envelope protein gp120-triggered CD4+ T-cell adhesion to vascular endothelium is regulated via CD4 and CXCR4 receptors. Biochim Biophys Acta Mol Basis Dis 2007; 1772:549-55. [PMID: 17346946 DOI: 10.1016/j.bbadis.2007.01.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Revised: 12/28/2006] [Accepted: 01/22/2007] [Indexed: 10/23/2022]
Abstract
Activation of T-lymphocytes is an important component of inflammatory and infectious processes, including HIV infection. It is regulated via the actions of various cell-surface receptors, including CD4 and CXCR4. We examined the roles of CD4 and CXCR4 in the adhesive interaction of CD4+T-cells with the vascular endothelium. CD4+Jurkat cells were incubated in the presence or absence of anti-CD4 to stimulate CD4, or with SDF-1 alpha, a cognate ligand of CXCR4. Stimulation of CD4 or CXCR4 each significantly enhanced cell adhesion. We next stimulated the two receptors together, using gp120, a component of HIV. This enhanced cell adhesion was greater than stimulation of CD4 or CXCR4 individually. Western blotting revealed that stimulation of CXCR4 by SDF-1 alpha significantly increased the phosphorylation of ERK1/2 in Jurkat cells. Treatment with anti-CD4 also activated ERK1/2, although to a lesser extent. When the expression of CD4 was reduced by siRNA transfection, both CD4-dependent adhesion and MAPK activation were diminished. Furthermore, pre-treatment with fluvastatin, significantly attenuated observed Jurkat cell adhesion. These findings indicate novel mechanisms of CD4+ T-cells recruitment to activated endothelium via CD4 and CXCR4, which are modulated by statin.
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Affiliation(s)
- Yoshio Takano
- Department of Vascular Medicine, Tokyo Medical and Dental University, Japan
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