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Yu X, Shang H, Jiang Y. ICAM-1 in HIV infection and underlying mechanisms. Cytokine 2019; 125:154830. [PMID: 31491723 DOI: 10.1016/j.cyto.2019.154830] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/29/2019] [Accepted: 08/24/2019] [Indexed: 02/07/2023]
Abstract
Intercellular adhesion molecule 1 (ICAM-1) is a glycoprotein that participates in inflammatory and immune responses. Both cell surface and soluble ICAM-1 are significantly increased during human immunodeficiency virus (HIV) infection, and ICAM-1 has important functions in promoting inflammatory responses and enhancing HIV infectivity; however, a comprehensive summary these roles has yet to be elaborated. In this review we describe the general biological characteristics of ICAM-1, its association with HIV disease progression and promotion of HIV production, mechanisms inducing upregulation of ICAM-1, and possible intervention strategies, representing important insights in the context of HIV treatment.
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Affiliation(s)
- Xiaowen Yu
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang 110001, China; National Clinical Research Center for Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of AIDS Immunology of Liaoning Province, The First Affiliated Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of AIDS Immunology, Chinese Academy of Medical Sciences, Shenyang 110001, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, 79 Qingchun Street, Hangzhou 310003, China
| | - Hong Shang
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang 110001, China; National Clinical Research Center for Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of AIDS Immunology of Liaoning Province, The First Affiliated Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of AIDS Immunology, Chinese Academy of Medical Sciences, Shenyang 110001, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, 79 Qingchun Street, Hangzhou 310003, China.
| | - Yongjun Jiang
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang 110001, China; National Clinical Research Center for Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of AIDS Immunology of Liaoning Province, The First Affiliated Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of AIDS Immunology, Chinese Academy of Medical Sciences, Shenyang 110001, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, 79 Qingchun Street, Hangzhou 310003, China.
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Liu L, Yu J, Li L, Zhang B, Liu L, Wu CH, Jong A, Mao DA, Huang SH. Alpha7 nicotinic acetylcholine receptor is required for amyloid pathology in brain endothelial cells induced by Glycoprotein 120, methamphetamine and nicotine. Sci Rep 2017; 7:40467. [PMID: 28074940 PMCID: PMC5225415 DOI: 10.1038/srep40467] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 12/06/2016] [Indexed: 01/12/2023] Open
Abstract
One of the most challenging issues in HIV-associated neurocognitive disorders (HAND) caused by HIV-1 virotoxins and drug abuse is the lack of understanding the underlying mechanisms that are commonly associated with disorders of the blood-brain barrier (BBB), which mainly consists of brain microvascular endothelial cells (BMEC). Here, we hypothesized that Glycoprotein 120 (gp120), methamphetamine (METH) and nicotine (NT) can enhance amyloid-beta (Aβ) accumulation in BMEC through Alpha7 nicotinic acetylcholine receptor (α7 nAChR). Both in vitro (human BMEC) (HBMEC) and in vivo (mice) models of BBB were used to dissect the role of α7 nAChR in up-regulation of Aβ induced by gp120, METH and NT. Aβ release from and transport across HBMEC were significantly increased by these factors. Methyllycaconitine (MLA), an antagonist of α7 nAChR, could efficiently block these pathogenic effects. Furthermore, our animal data showed that these factors could significantly increase the levels of Aβ, Tau and Ubiquitin C-Terminal Hydrolase L1 (UCHL1) in mouse cerebrospinal fluid (CSF) and Aβ in the mouse brains. These pathogenicities were significantly reduced by MLA, suggesting that α7 nAChR may play an important role in neuropathology caused by gp120, METH and NT, which are the major pathogenic factors contributing to the pathogenesis of HAND.
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Affiliation(s)
- Liqun Liu
- Department of Pediatrics, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China.,Saban Research Institute, Childrens Hospital Los Angeles, University of Southern California, Los Angeles, CA90027, USA
| | - Jingyi Yu
- Saban Research Institute, Childrens Hospital Los Angeles, University of Southern California, Los Angeles, CA90027, USA.,School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Li Li
- School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.,Department of Clinical Laboratory, Kunming Children's Hospital, Kunming Medical University, Kunming, Yunnan 650034, China
| | - Bao Zhang
- Saban Research Institute, Childrens Hospital Los Angeles, University of Southern California, Los Angeles, CA90027, USA.,School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Lingjuan Liu
- Department of Pediatrics, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Chun-Hua Wu
- Saban Research Institute, Childrens Hospital Los Angeles, University of Southern California, Los Angeles, CA90027, USA
| | - Ambrose Jong
- Saban Research Institute, Childrens Hospital Los Angeles, University of Southern California, Los Angeles, CA90027, USA
| | - Ding-An Mao
- Department of Pediatrics, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Sheng-He Huang
- Saban Research Institute, Childrens Hospital Los Angeles, University of Southern California, Los Angeles, CA90027, USA.,School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China
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Zhang B, Yu JY, Liu LQ, Peng L, Chi F, Wu CH, Jong A, Wang SF, Cao H, Huang SH. Alpha7 nicotinic acetylcholine receptor is required for blood-brain barrier injury-related CNS disorders caused by Cryptococcus neoformans and HIV-1 associated comorbidity factors. BMC Infect Dis 2015; 15:352. [PMID: 26285576 PMCID: PMC4543465 DOI: 10.1186/s12879-015-1075-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 07/31/2015] [Indexed: 01/11/2023] Open
Abstract
Background Cryptococcal meningitis is the most common fungal infection of the central nervous system (CNS) in HIV/AIDS. HIV-1 virotoxins (e.g., gp41) are able to induce disorders of the blood-brain barrier (BBB), which mainly consists of BMEC. Our recent study suggests that α7 nAChR is an essential regulator of inflammation, which contributes to regulation of NF-κB signaling, neuroinflammation and BBB disorders caused by microbial (e.g., HIV-1 gp120) and non-microbial [e.g., methamphetamine (METH)] factors. However, the underlying mechanisms for multiple comorbidities are unclear. Methods In this report, an aggravating role of α7 nAChR in host defense against CNS disorders caused by these comorbidities was demonstrated by chemical [inhibitor: methyllycaconitine (MLA)] and genetic (α7−/− mice) blockages of α7 nAChR. Results As shown in our in vivo studies, BBB injury was significantly reduced in α7−/− mice infected with C. neoformans. Stimulation by the gp41 ectodomain peptide (gp41-I90) and METH was abolished in the α7−/− animals. C. neoformans and gp41-I90 could activate NF-κB. Gp41-I90- and METH-induced monocyte transmigration and senescence were significantly inhibited by MLA and CAPE (caffeic acid phenethyl ester, an NF-κB inhibitor). Conclusions Collectively, our data suggest that α7 nAChR plays a detrimental role in the host defense against C. neoformans- and HIV-1 associated comorbidity factors-induced BBB injury and CNS disorders.
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Affiliation(s)
- Bao Zhang
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China. .,Saban Research Institute of Childrens Hospital Los Angeles, Department of Pediatrics, University of Southern California, 4650 Sunset Blvd., Mailstop #51, Los Angeles, CA, 90027, USA.
| | - Jing-Yi Yu
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China. .,Saban Research Institute of Childrens Hospital Los Angeles, Department of Pediatrics, University of Southern California, 4650 Sunset Blvd., Mailstop #51, Los Angeles, CA, 90027, USA.
| | - Li-Qun Liu
- Division of Pediatric Neurology, Children's Medical Center, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China.
| | - Liang Peng
- Saban Research Institute of Childrens Hospital Los Angeles, Department of Pediatrics, University of Southern California, 4650 Sunset Blvd., Mailstop #51, Los Angeles, CA, 90027, USA. .,Department of Clinic Laboratory, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510260, China.
| | - Feng Chi
- Saban Research Institute of Childrens Hospital Los Angeles, Department of Pediatrics, University of Southern California, 4650 Sunset Blvd., Mailstop #51, Los Angeles, CA, 90027, USA.
| | - Chun-Hua Wu
- Saban Research Institute of Childrens Hospital Los Angeles, Department of Pediatrics, University of Southern California, 4650 Sunset Blvd., Mailstop #51, Los Angeles, CA, 90027, USA.
| | - Ambrose Jong
- Saban Research Institute of Childrens Hospital Los Angeles, Department of Pediatrics, University of Southern California, 4650 Sunset Blvd., Mailstop #51, Los Angeles, CA, 90027, USA.
| | - Shi-Fu Wang
- Saban Research Institute of Childrens Hospital Los Angeles, Department of Pediatrics, University of Southern California, 4650 Sunset Blvd., Mailstop #51, Los Angeles, CA, 90027, USA. .,Department of Children's Medical Laboratory Diagnosis Center, Qilu Children's Hospital of Shandong University, Jinan, 250022, China.
| | - Hong Cao
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Sheng-He Huang
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China. .,Saban Research Institute of Childrens Hospital Los Angeles, Department of Pediatrics, University of Southern California, 4650 Sunset Blvd., Mailstop #51, Los Angeles, CA, 90027, USA.
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Sun D, Wu Y, Yuan Y, Wang Y, Liu W, Yang J. Is the atherosclerotic process accentuated under conditions of HIV infection, antiretroviral therapy, and protease inhibitor exposure? Meta-analysis of the markers of arterial structure and function. Atherosclerosis 2015; 242:109-16. [PMID: 26188532 DOI: 10.1016/j.atherosclerosis.2015.06.059] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 03/17/2015] [Accepted: 06/30/2015] [Indexed: 01/07/2023]
Abstract
OBJECTIVE To evaluate the apparent association of human immunodeficiency virus (HIV) infection, antiretroviral therapy (ART), and protease inhibitor (PI) exposure with the functional and structural markers of vasculature. METHODS A meta-analysis of the relationship between HIV infection, ART, and PI exposure and the functional and structural markers of vasculature. A systematic literature search was performed electronically using specific eligibility criteria. Weighted mean difference (WMD) and corresponding 95% confidence interval (CI) were calculated and combined appropriately. RESULTS Fifty-seven articles were included with nine different outcomes. Compared with HIV-negative patients, HIV-positive patients demonstrated significant elevated intima-media thickness (IMT) (WMD (95% CI) = 0.042 (0.028-0.057)), increased pulse wave velocity (PWV) (0.538 (0.283-0.792)), and reduced flow-mediated vasodilation (FMD) (-2.049 (-2.806 to -1.293)). Elevated IMT was observed in HIV patients receiving ART when compared with those naïve to ART in the 20- to 40-year-old age group (0.078 (0.033-0.123)), the >40-year-old age group (0.038 (0.018-0.057)), and the group comprising >50% males (0.070 (0.041-0.099)). In addition, ART resulted in an increased PWV in HIV patients receiving ART in the group with >50% male proportion (0.628 (0.405-0.851)). HIV patients exposed to PI showed a significant trend toward elevated IMT (0.033 (0.007-0.058)) and increased PWV (0.264 (0.118-0.410)) compared with those without PI exposure. CONCLUSIONS The atherosclerotic process was accentuated by elevated IMT, increased PWV, and reduced FMD under condition of HIV infection. Comparison of ART-receiving with ART-naïve patients showed a significant trend toward elevated IMT and increased PWV, especially under treatment with PI-containing drugs.
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Affiliation(s)
- Dandan Sun
- Department of Cardiovascular Ultrasound, The First Affiliated Hospital of China Medical University, Liaoning Province, Shenyang 110001, China
| | - Yupeng Wu
- Department of Neurosurgery, The First Affiliated Hospital of China Medical University, Liaoning Province, Shenyang 110001, China
| | - Yuan Yuan
- Department of Tumor Etiology and Screening, Cancer Institute and General Surgery, The First Affiliated Hospital of China Medical University, and Key Laboratory of Cancer Etiology and Prevention, Liaoning Provincial Education Department, Shenyang 110001, China
| | - Yun Wang
- Department of Cardiovascular Ultrasound, The First Affiliated Hospital of China Medical University, Liaoning Province, Shenyang 110001, China
| | - Wen Liu
- Department of Cardiovascular Ultrasound, The First Affiliated Hospital of China Medical University, Liaoning Province, Shenyang 110001, China
| | - Jun Yang
- Department of Cardiovascular Ultrasound, The First Affiliated Hospital of China Medical University, Liaoning Province, Shenyang 110001, China.
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Hussmann KL, Vandergaast R, Zheng K, Hoover LI, Fredericksen BL. Structural proteins of West Nile virus are a major determinant of infectious particle production and fitness in astrocytes. J Gen Virol 2014; 95:1991-2003. [PMID: 24920724 PMCID: PMC4135089 DOI: 10.1099/vir.0.065474-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The molecular basis for the increased resistance of astrocytes to a non-neuropathogenic strain of West Nile virus (WNV), WNV-MAD78, compared with the neuropathogenic strain WNV-NY remains unclear. Here, we demonstrated that the reduced susceptibility of astrocytes to WNV-MAD78 is due to a combination of both cellular activities as well as viral determinants. Analyses of the viral particle indicated that astrocyte-derived WNV-MAD78 particles were less infectious than those of WNV-NY. Additionally, inhibition of cellular furin-like proteases increased WNV-MAD78 infectious particle production in astrocytes, suggesting that high levels of furin-like protease activity within these cells acted in a cell- and strain-specific manner to inhibit WNV-MAD78 replication. Moreover, analysis of recombinant viruses indicated that the structural proteins of WNV-MAD78 were responsible for decreased particle infectivity and the corresponding reduction in infectious particle production compared with WNV-NY. Thus, the composition of the WNV virion was also a major determinant for viral fitness within astrocytes and may contribute to WNV propagation within the central nervous system. Whether the WNV-MAD78 structural genes reduce virus replication and particle infectivity through the same mechanism as the cellular furin-like protease activity or whether these two determinants function through distinct pathways remains to be determined.
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Affiliation(s)
- Katherine L Hussmann
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Rianna Vandergaast
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Kang Zheng
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Lisa I Hoover
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Brenda L Fredericksen
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA.,Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, 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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Gibellini D, Borderi M, Clò A, Morini S, Miserocchi A, Bon I, Ponti C, Re MC. HIV-related mechanisms in atherosclerosis and cardiovascular diseases. J Cardiovasc Med (Hagerstown) 2013; 14:780-90. [DOI: 10.2459/jcm.0b013e3283619331] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Huang SH, Wang L, Chi F, Wu CH, Cao H, Zhang A, Jong A. Circulating brain microvascular endothelial cells (cBMECs) as potential biomarkers of the blood-brain barrier disorders caused by microbial and non-microbial factors. PLoS One 2013; 8:e62164. [PMID: 23637989 PMCID: PMC3637435 DOI: 10.1371/journal.pone.0062164] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 03/18/2013] [Indexed: 11/18/2022] Open
Abstract
Despite aggressive research, central nervous system (CNS) disorders, including blood-brain barrier (BBB) injury caused by microbial infection, stroke, abused drugs [e.g., methamphetamine (METH) and nicotine], and other pathogenic insults, remain the world's leading cause of disabilities. In our previous work, we found that dysfunction of brain microvascular endothelial cells (BMECs), which are a major component of the BBB, could be caused by nicotine, meningitic pathogens and microbial factors, including HIV-1 virulence factors gp41 and gp120. One of the most challenging issues in this area is that there are no available cell-based biomarkers in peripheral blood for BBB disorders caused by microbial and non-microbial insults. To identify such cellular biomarkers for BBB injuries, our studies have shown that mice treated with nicotine, METH and gp120 resulted in increased blood levels of CD146+(endothelial marker)/S100B+ (brain marker) circulating BMECs (cBMECs) and CD133+[progenitor cell (PC) marker]/CD146+ endothelial PCs (EPCs), along with enhanced Evans blue and albumin extravasation into the brain. Nicotine and gp120 were able to significantly increase the serum levels of ubiquitin C-terminal hydrolase 1 (UCHL1) (a new BBB marker) as well as S100B in mice, which are correlated with the changes in cBMECs and EPCs. Nicotine- and meningitic E. coli K1-induced enhancement of cBMEC levels, leukocyte migration across the BBB and albumin extravasation into the brain were significantly reduced in alpha7 nAChR knockout mice, suggesting that this inflammatory regulator plays an important role in CNS inflammation and BBB disorders caused by microbial and non-microbial factors. These results demonstrated that cBMECs as well as EPCs may be used as potential cell-based biomarkers for indexing of BBB injury.
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Affiliation(s)
- Sheng-He Huang
- Department of Pediatrics, Saban Research Institute of Childrens Hospital Los Angeles, University of Southern California, Los Angeles, California, United States of America.
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Ridgway LD, Wetzel MD, Ngo JA, Erdreich-Epstein A, Marchetti D. Heparanase-induced GEF-H1 signaling regulates the cytoskeletal dynamics of brain metastatic breast cancer cells. Mol Cancer Res 2012; 10:689-702. [PMID: 22513363 DOI: 10.1158/1541-7786.mcr-11-0534] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Heparanase is the only mammalian endoglycosidase which has been widely implicated in cancer because of its capability to degrade heparan sulfate chains of heparan sulfate proteoglycans (HSPG). Specifically, the cell surface HSPG syndecan-1 and -4 (SDC1 and SDC4) are modulators of growth factor action, and SDC4 is implicated in cell adhesion as a key member of focal adhesion complexes. We hypothesized that extracellular heparanase modulates brain metastatic breast cancer (BMBC) cell invasiveness by affecting cytoskeletal dynamics, SDC4 carboxy-terminal-associated proteins, and downstream targets. We used two independently derived human BMBC cell systems (MB-231BR and MB-231BR3), which possess distinct cellular morphologies and properties. Highly aggressive spindle-shaped 231BR3 cells changed to a round cell morphology associated with expression of the small GTPase guanine nucleotide exchange factor-H1 (GEF-H1). We showed that GEF-H1 is a new component of the SDC4 signaling complex in BMBC cells. Treatment with heparanase resulted in regulation of the SDC4/protein kinase C α axis while maintaining a constitutive GEF-H1 level. Third, GEF-H1 knockdown followed by cell exposure to heparanase caused a significant regulation of activities of Rac1 and RhoA, which are GEF-H1 targets and fundamental effectors in cell plasticity control. Fourth, L-heparanase augmented expression of β1 integrin in BMBC cells and of vascular cell adhesion molecule 1 (VCAM1; the major β1 integrin receptor) in human brain microvascular endothelial cells. Finally, using a newly developed blood-brain barrier in vitro model, we show that BMBC cell transmigration was significantly reduced in GEF-H1 knockdown cells. These findings implicate heparanase in mechanisms of cytoskeletal dynamics and in the cross-talk between tumor cells and vascular brain endothelium. They are of relevance because they elucidate molecular events in the initial steps leading to BMBC onset and capturing distinct roles of latent and active heparanase in the brain microenvironment.
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Affiliation(s)
- Lon D Ridgway
- Department of Pathology & Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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Louboutin JP, Strayer DS. Blood-brain barrier abnormalities caused by HIV-1 gp120: mechanistic and therapeutic implications. ScientificWorldJournal 2012; 2012:482575. [PMID: 22448134 PMCID: PMC3289936 DOI: 10.1100/2012/482575] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Accepted: 11/20/2011] [Indexed: 12/04/2022] Open
Abstract
The blood-brain barrier (BBB) is compromised in many systemic and CNS diseases, including HIV-1 infection of the brain. We studied BBB disruption caused by HIV-1 envelope glycoprotein 120 (gp120) as a model. Exposure to gp120, whether acute [by direct intra-caudate-putamen (CP) injection] or chronic [using SV(gp120), an experimental model of ongoing production of gp120] disrupted the BBB, and led to leakage of vascular contents. Gp120 was directly toxic to brain endothelial cells. Abnormalities of the BBB reflect the activity of matrix metalloproteinases (MMPs). These target laminin and attack the tight junctions between endothelial cells and BBB basal laminae. MMP-2 and MMP-9 were upregulated following gp120-injection. Gp120 reduced laminin and tight junction proteins. Reactive oxygen species (ROS) activate MMPs. Injecting gp120 induced lipid peroxidation. Gene transfer of antioxidant enzymes protected against gp120-induced BBB abnormalities. NMDA upregulates the proform of MMP-9. Using the NMDA receptor (NMDAR-1) inhibitor, memantine, we observed partial protection from gp120-induced BBB injury. Thus, (1) HIV-envelope gp120 disrupts the BBB; (2) this occurs via lesions in brain microvessels, MMP activation and degradation of vascular basement membrane and vascular tight junctions; (3) NMDAR-1 activation plays a role in this BBB injury; and (4) antioxidant gene delivery as well as NMDAR-1 antagonists may protect the BBB.
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Affiliation(s)
- Jean-Pierre Louboutin
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, 1020 Locust Street Room 255 Philadelphia, PA 19107, USA.
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Be NA, Bishai WR, Jain SK. Role of Mycobacterium tuberculosis pknD in the pathogenesis of central nervous system tuberculosis. BMC Microbiol 2012; 12:7. [PMID: 22243650 PMCID: PMC3322341 DOI: 10.1186/1471-2180-12-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Accepted: 01/13/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Central nervous system disease is the most serious form of tuberculosis, and is associated with high mortality and severe neurological sequelae. Though recent clinical reports suggest an association of distinct Mycobacterium tuberculosis strains with central nervous system disease, the microbial virulence factors required have not been described previously. RESULTS We screened 398 unique M. tuberculosis mutants in guinea pigs to identify genes required for central nervous system tuberculosis. We found M. tuberculosis pknD (Rv0931c) to be required for central nervous system disease. These findings were central nervous system tissue-specific and were not observed in lung tissues. We demonstrated that pknD is required for invasion of brain endothelia (primary components of the blood-brain barrier protecting the central nervous system), but not macrophages, lung epithelia, or other endothelia. M. tuberculosis pknD encodes a "eukaryotic-like" serine-threonine protein kinase, with a predicted intracellular kinase and an extracellular (sensor) domain. Using confocal microscopy and flow cytometry we demonstrated that the M. tuberculosis PknD sensor is sufficient to trigger invasion of brain endothelia, a process which was neutralized by specific antiserum. CONCLUSIONS Our findings demonstrate a novel in vivo role for M. tuberculosis pknD and represent an important mechanism for bacterial invasion and virulence in central nervous system tuberculosis, a devastating and understudied disease primarily affecting young children.
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Affiliation(s)
- Nicholas A Be
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, 1550 Orleans Street, Baltimore, Maryland 21287, USA
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Chi F, Wang L, Zheng X, Wu CH, Jong A, Sheard MA, Shi W, Huang SH. Meningitic Escherichia coli K1 penetration and neutrophil transmigration across the blood-brain barrier are modulated by alpha7 nicotinic receptor. PLoS One 2011; 6:e25016. [PMID: 21966399 PMCID: PMC3178609 DOI: 10.1371/journal.pone.0025016] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 08/22/2011] [Indexed: 11/19/2022] Open
Abstract
Alpha7 nicotinic acetylcholine receptor (nAChR), an essential regulator of inflammation, is abundantly expressed in hippocampal neurons, which are vulnerable to bacterial meningitis. However, it is unknown whether α7 nAChR contributes to the regulation of these events. In this report, an aggravating role of α7 nAChR in host defense against meningitic E. coli infection was demonstrated by using α7-deficient (α7(-/-)) mouse brain microvascular endothelial cells (BMEC) and animal model systems. As shown in our in vitro and in vivo studies, E. coli K1 invasion and polymorphonuclear neutrophil (PMN) transmigration across the blood-brain barrier (BBB) were significantly reduced in α7(-/-) BMEC and α7(-/-) mice. Stimulation by nicotine was abolished in the α7(-/-) cells and animals. The same blocking effect was achieved by methyllycaconitine (α7 antagonist). The tight junction molecules occludin and ZO-1 were significantly reduced in the brain cortex of wildtype mice infected with E. coli and treated with nicotine, compared to α7(-/-) cells and animals. Decreased neuronal injury in the hippocampal dentate gyrus was observed in α7(-/-) mice with meningitis. Proinflammatory cytokines (IL-1β, IL-6, TNFα, MCP-1, MIP-1alpha, and RANTES) and adhesion molecules (CD44 and ICAM-1) were significantly reduced in the cerebrospinal fluids of the α7(-/-) mice with E. coli meningitis. Furthermore, α7 nAChR is the major calcium channel for nicotine- and E. coli K1-increased intracellular calcium concentrations of mouse BMEC. Taken together, our data suggest that α7 nAChR plays a detrimental role in the host defense against meningitic infection by modulation of pathogen invasion, PMN recruitment, calcium signaling and neuronal inflammation.
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Affiliation(s)
- Feng Chi
- Department of Pediatrics, Saban Research Institute, University of Southern California, Childrens Hospital Los Angeles, Los Angeles, California, United States of America
| | - Lin Wang
- Department of Pediatrics, Saban Research Institute, University of Southern California, Childrens Hospital Los Angeles, Los Angeles, California, United States of America
- Department of Histology and Embryology, School of Basic Medical Science, Wuhan University, Wuhan, China
| | - Xueye Zheng
- Department of Pediatrics, Saban Research Institute, University of Southern California, Childrens Hospital Los Angeles, Los Angeles, California, United States of America
| | - Chun-Hua Wu
- Department of Pediatrics, Saban Research Institute, University of Southern California, Childrens Hospital Los Angeles, Los Angeles, California, United States of America
| | - Ambrose Jong
- Department of Pediatrics, Saban Research Institute, University of Southern California, Childrens Hospital Los Angeles, Los Angeles, California, United States of America
| | - Michael A. Sheard
- Department of Pediatrics, Saban Research Institute, University of Southern California, Childrens Hospital Los Angeles, Los Angeles, California, United States of America
| | - Wei Shi
- Department of Pediatrics, Saban Research Institute, University of Southern California, Childrens Hospital Los Angeles, Los Angeles, California, United States of America
| | - Sheng-He Huang
- Department of Pediatrics, Saban Research Institute, University of Southern California, Childrens Hospital Los Angeles, Los Angeles, California, United States of America
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Grab DJ, Chakravorty SJ, van der Heyde H, Stins MF. How can microbial interactions with the blood-brain barrier modulate astroglial and neuronal function? Cell Microbiol 2011; 13:1470-8. [DOI: 10.1111/j.1462-5822.2011.01661.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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14
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Che X, Chi F, Wang L, Jong TD, Wu CH, Wang X, Huang SH. Involvement of IbeA in meningitic Escherichia coli K1-induced polymorphonuclear leukocyte transmigration across brain endothelial cells. Brain Pathol 2010; 21:389-404. [PMID: 21083634 DOI: 10.1111/j.1750-3639.2010.00463.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Transmigration of neutrophil [polymorphonuclear neutrophil (PMN)] across the blood-brain barrier (BBB) is a critical event in the pathogenesis of bacterial meningitis. We have shown that IbeA is able to induce meningitic Escherichia coli invasion of brain microvascular endothelial cells (BMECs), which constitutes the BBB. In this report, we provide evidence that IbeA and its receptor, vimentin, play a key role in E. coli-induced PMN transmigration across BMEC. In vitro and in vivo studies indicated that the ibeA-deletion mutant ZD1 was significantly less active in stimulating PMN transmigration than the parent strain E44. ZD1 was fully complemented by the ibeA gene and its product. E. coli-induced PMN transmigration was markedly inhibited by withaferin A, a dual inhibitor of vimentin and proteasome. These cellular effects were significantly stimulated and blocked by overexpression of vimentin and its head domain deletion mutant in human BMEC, respectively. Our studies further demonstrated that IbeA-induced PMN migration was blocked by bortezomib, a proteasomal inhibitor and correlated with upregulation of endothelial ICAM-1 and CD44 expression through proteasomal regulation of NFκB activity. Taken together, our data suggested that IbeA and vimentin contribute to E. coli K1-stimulated PMN transendothelial migration that is correlated with upregulation of adhesion molecule expression at the BBB.
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Affiliation(s)
- Xiaojuan Che
- Saban Research Institute of Childrens Hospital Los Angeles, Department of Pediatrics, University of Southern California, Los Angeles, CA 90027, USA
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15
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Patel N, Kalra VK. Placenta growth factor-induced early growth response 1 (Egr-1) regulates hypoxia-inducible factor-1alpha (HIF-1alpha) in endothelial cells. J Biol Chem 2010; 285:20570-9. [PMID: 20448047 DOI: 10.1074/jbc.m110.119495] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leukotrienes, the lipid inflammatory products derived from arachidonic acid, are involved in the pathogenesis of respiratory and cardiovascular diseases and reactive airway disease in sickle cell disease. Placenta growth factor (PlGF), elaborated from erythroid cells, increased the mRNA expression of 5-lipoxygenase and 5-lipoxygenase-activating protein (FLAP) in human pulmonary microvascular endothelial cells. PlGF-induced both promoter activity and mRNA expression of hypoxia-inducible factor-1alpha (HIF-1alpha), which was abrogated by early growth response-1 (EGR-1) small interfering RNA. PlGF showed a temporal reciprocal relationship in the mRNA levels of EGR-1 and NAB2, the latter a repressor of Egr-1. Moreover, Nab2, but not mutant Nab2, significantly reduced promoter activity and mRNA expression of HIF-1alpha and also reduced expression of the HIF-1alpha target gene FLAP. Furthermore, overexpression of Egr-1 led to increased promoter activities for both HIF-1alpha and FLAP in the absence of PlGF. Additionally, the Egr-1-mediated induction of HIF-1alpha and FLAP promoters was reduced to basal levels by EGR-1 small interfering RNA. The binding of Egr-1 to HIF-1alpha promoter was corroborated by electrophoretic mobility shift assay and chromatin immunoprecipitation assay, which showed increased Egr-1 binding to the HIF-1alpha promoter in response to PlGF stimulation. These studies provide a novel mechanism for PlGF-mediated regulation of HIF-1alpha via Egr-1, which results in increased FLAP expression. This study provides a new therapeutic target, namely Egr-1, for attenuation of elevated leukotriene levels in patients with sickle cell disease and other inflammatory diseases.
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Affiliation(s)
- Nitin Patel
- Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
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16
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Banks WA. Mouse models of neurological disorders: a view from the blood-brain barrier. Biochim Biophys Acta Mol Basis Dis 2009; 1802:881-8. [PMID: 19879356 DOI: 10.1016/j.bbadis.2009.10.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 10/20/2009] [Accepted: 10/23/2009] [Indexed: 12/16/2022]
Abstract
The number of disease models that involve an aspect of blood-brain barrier (BBB) dysregulation have increased tremendously. The main factors contributing to this expansion have been an increased number of diseases in which the BBB is known to be involved, an increase in the known functions of the BBB, and an increase in the number of models and tools with which those diverse functions can be studied. In many cases, the BBB may be a target of disease; current thinking would include hypertensive encephalopathy and perhaps stroke in this category. Another category are those diseases in which special attributes of the BBB may predispose to disease; for example, the ability of a pathogen to cross the BBB often depends on the pathogen's ability to invoke transcytotic pathways in the brain endothelial or choroid plexus cell. Of special interest are those diseases in which the BBB may be the primary seat of disease or play a major role in the onset or progression of the disease. An increasing number of diseases are so categorized in which BBB dysfunction or dysregulation plays a major role; this review highlights such roles for the BBB including those proposed for Alzheimer's disease and obesity.
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Affiliation(s)
- William A Banks
- GRECC, Veterans Affairs Medical Center-St. Louis and Saint Louis University School of Medicine, Division of Geriatrics, Department of Internal Medicine, 915 N. Grand Blvd, St. Louis, MO 63106, USA.
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HIV-1 gp120 induces cytokine expression, leukocyte adhesion, and transmigration across the blood-brain barrier: modulatory effects of STAT1 signaling. Microvasc Res 2008; 77:212-9. [PMID: 19103208 DOI: 10.1016/j.mvr.2008.11.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Accepted: 11/12/2008] [Indexed: 01/24/2023]
Abstract
How neuroinflammatory activities affect signaling pathways leading to blood-brain barrier (BBB) injury during HIV/AIDS are currently unknown. Our previous work demonstrated that HIV-1 exposure activates pro-inflammatory genes in human brain microvascular endothelial cells (HBMEC) and showed that these genes are linked to the janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway. Here, we report that HIV-1 gp120 protein activated STAT1 and induced interleukin (IL)-6 and IL-8 secretion in HBMEC. IL-6, IL-8, and gp120 increased monocyte adhesion and migration across in vitro BBB models. The STAT1 inhibitor, fludarabine, prevented gp120-induced IL-6 and IL-8 secretion. Inhibitors of STAT1, mitogen activated protein kinase kinase (MEK) (PD98059), and phosphatidyl inositol 3 kinase (PI3K) (LY294002), blocked gp120-induced STAT1 activation and significantly diminished IL-8-, IL-6-, and gp120-induced monocyte adhesion and migration across in vitro BBB models. These data support the notion that STAT1 plays an important role in gp120-induced inflammation and BBB dysfunction associated with viral infection. Results also suggest crosstalk between STAT1, MEK, and PI3K pathways in gp120-induced BBB dysfunction. Inhibition of STAT1 activation could provide a unique therapeutic strategy to decrease neuroinflammation and BBB dysfunction in HIV/AIDS.
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Khan NA, Di Cello F, Stins M, Kim KS. Gp120-mediated cytotoxicity of human brain microvascular endothelial cells is dependent on p38 mitogen-activated protein kinase activation. J Neurovirol 2007; 13:242-51. [PMID: 17613714 DOI: 10.1080/13550280701286531] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Breakdown of the blood-brain barrier has been shown to contribute to neurological disorders that are prevalent in human immunodeficiency virus type 1 (HIV-1)-infected individuals, but the mechanisms involved in HIV-1-associated blood-brain barrier dysfunction remain incompletely understood. Using human brain microvascular endothelial cells (HBMECs) that constitute the blood-brain barrier, the authors determined the cytotoxic effects of gp120 on HBMECs. The authors showed that gp120 induced cytotoxicity of HBMECs derived from children, which required cotreatment with interferon (IFN)-gamma. IFN-gamma treatment exhibited up-regulation of the chemokine receptors CCR3 and CCR5 in children's HBMECs. In contrast, HBMECs isolated from adults were not responsive to gp120-mediated cytotoxicity. Peptides of gp120 representing binding regions for CD4 and chemokine receptors as well as CD4 antibody inhibited gp120-mediated cytotoxicity of HBMECs. RANTES, as expected, inhibited M-tropic gp120-mediated HBMEC cytotoxicity, whereas stromal cell-derived factor (SDF)-1alpha failed to inhibit T-tropic gp120-mediated cytotoxicity. Of interest, gp120 peptides representing non-CD4/non-chemokine receptor binding regions inhibited gp120-mediated HBMEC cytotoxicity. In addition, the authors showed that gp120-mediated HBMEC cytotoxicity involved p38 mitogen-activated protein kinase pathway. Taken together, these findings showed that gp120, in the presence of IFN-gamma, can cause dysfunction of the blood-brain barrier endothelium via MAPK pathways involving several gp120-HBMEC interactions.
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Affiliation(s)
- Naveed Ahmed Khan
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
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19
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Shiu C, Barbier E, Di Cello F, Choi HJ, Stins M. HIV-1 gp120 as well as alcohol affect blood-brain barrier permeability and stress fiber formation: involvement of reactive oxygen species. Alcohol Clin Exp Res 2007; 31:130-7. [PMID: 17207111 DOI: 10.1111/j.1530-0277.2006.00271.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND HIV-1 infection commonly leads to serious HIV-1-associated neurological disorders, such as HIV-1-associated encephalopathy and dementia. In addition, alcohol is commonly used and/or abused among AIDS patients, but it is unclear whether alcohol affects the disease progression and if it affects it, how this occurs. We hypothesized that alcohol could affect the blood-brain barrier (BBB) integrity and thus could affect the onset and/or progression of HIV-associated neurological disorders. METHODS Human brain microvascular endothelial cells (HBMEC) in a BBB model system were pretreated with alcohol (17 and 68 mM) and subsequently coexposed with HIV-1 gp120. Expression of chemokine receptors CCR3, CCR5, and CXCR4 was assessed by enzyme-linked immunosorbent assay and real-time polymerase chain reaction. Changes in the permeability of the HBMEC monolayer were assessed using paracellular markers [(3)H]inulin or propidium iodide. Actin rearrangements in HBMEC were visualized by fluorescence microscopy and viability assessed using Live/Dead stain. RESULTS Both gp120 and alcohol increased the permeability of the BBB model by up to 141%, without affecting HBMEC viability. Cotreatment with alcohol and gp120 did not result in a significant synergistic effect. Gp120 permeability involved chemokine receptor CCR5. Alcohol did not affect chemokine receptor expression on brain endothelial cells. Both gp120 and alcohol reorganized the cytoskeleton and induced stress fiber formation. Inhibition of reactive oxygen species (ROS) formation through NADPH blocked the effects of both gp120 and alcohol on permeability and stress fiber formation. CONCLUSION These results indicate that both HIV-1 gp120 and alcohol induce stress fibers, causing increased permeability of the human BBB endothelium. Alcohol (68 mM)-mediated permeability increase was linked to ROS formation. The alcohol-mediated physiological changes in the HBMEC monolayers may increase diffusion of plasma components and viral penetration across the BBB. This suggests that alcohol, especially at levels attained in heavy drinkers, can potentially contribute in a negative fashion to HIV-1 neuropathogenesis.
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Affiliation(s)
- Carlum Shiu
- Department of Pediatrics, Division Infectious Diseases, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Baltimore, MD 21205, USA
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20
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Mu H, Chai H, Lin PH, Yao Q, Chen C. Current Update on HIV-associated Vascular Disease and Endothelial Dysfunction. World J Surg 2007; 31:632-43. [PMID: 17372667 DOI: 10.1007/s00268-006-0730-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Highly active antiretroviral therapy (HAART) has greatly reduced the risk of early death from opportunistic infections and extended the lifespan of people infected with the human immunodeficiency virus (HIV). Thus, many complications and organic damage in the HIV-infected population emerge. Cardiovascular disease as coronary artery disease has become a matter of particular concern. Its incidence is greatly increased in the HIV-infected population over that of people of the same age in the absence of general cardiovascular risk factors. Despite several clinical and laboratory studies in the association between HIV infection and cardiovascular disease, the pathogenic mechanisms of this significant clinical problem are largely unknown and are now under active investigation. Endothelial dysfunction is possibly the most plausible link between HIV infection and atherosclerosis. Increased expression of adhesion molecules such as intercellular adhesion molecule (ICAM)-1 and endothelial adhesion molecule (E-selectin) and inflammatory cytokines such as tumor necrosis factor (TNF)-alpha and interleukin (IL-6 has been reported in HIV-positive patients. The effect of HAART on endothelial function in HIV-positive patients is also demonstrated. In this review, we focus on the recent research update of HIV-associated vascular disease and vascular injury. We analyze and discuss the recent clinical and laboratory investigations on the effect of HIV, viral protein, and HAART therapy on endothelial injury and vascular disease; identify the areas of controversy and clinical relevance; and suggest some directions for future research.
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Affiliation(s)
- Hong Mu
- Molecular Surgeon Research Center, Division of Vascular Surgery and Endovascular Therapy, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, One Baylor Plaza, Mail stop: NAB-2010, Houston, Texas 77030, USA
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21
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Ghafouri M, Amini S, Khalili K, Sawaya BE. HIV-1 associated dementia: symptoms and causes. Retrovirology 2006; 3:28. [PMID: 16712719 PMCID: PMC1513597 DOI: 10.1186/1742-4690-3-28] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2006] [Accepted: 05/19/2006] [Indexed: 11/18/2022] Open
Abstract
Despite the use of highly active antiretroviral therapy (HAART), neuronal cell death remains a problem that is frequently found in the brains of HIV-1-infected patients. HAART has successfully prevented many of the former end-stage complications of AIDS, however, with increased survival times, the prevalence of minor HIV-1 associated cognitive impairment appears to be rising among AIDS patients. Further, HIV-1 associated dementia (HAD) is still prevalent in treated patients as well as attenuated forms of HAD and CNS opportunistic disorders. HIV-associated cognitive impairment correlates with the increased presence in the CNS of activated, though not necessarily HIV-1-infected, microglia and CNS macrophages. This suggests that indirect mechanisms of neuronal injury and loss/death occur in HIV/AIDS as a basis for dementia since neurons are not themselves productively infected by HIV-1. In this review, we discussed the symptoms and causes leading to HAD. Outcome from this review will provide new information regarding mechanisms of neuronal loss in AIDS patients.
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Affiliation(s)
- Mohammad Ghafouri
- Department of Neuroscience, Center for Neurovirology, Temple University School of Medicine, Pennsylvania 19122, USA
| | - Shohreh Amini
- Department of Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Kamel Khalili
- Department of Neuroscience, Center for Neurovirology, Temple University School of Medicine, Pennsylvania 19122, USA
| | - Bassel E Sawaya
- Department of Neuroscience, Center for Neurovirology, Temple University School of Medicine, Pennsylvania 19122, USA
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22
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Paul-Satyaseela M, Xie Y, Di Cello F, Kim KS. Responses of brain and non-brain endothelial cells to meningitis-causing Escherichia coli K1. Biochem Biophys Res Commun 2006; 342:81-5. [PMID: 16472773 DOI: 10.1016/j.bbrc.2006.01.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2006] [Accepted: 01/25/2006] [Indexed: 12/01/2022]
Abstract
Bacterial interaction with specific host tissue may contribute to its propensity to cause an infection in a particular site. In this study, we examined whether meningitis-causing Escherichia coli K1 interaction with human brain microvascular endothelial cells, which constitute the blood-brain barrier, differed from its interaction with non-brain endothelial cells derived from skin and umbilical cord. We showed that E. coli K1 association was significantly greater with human brain microvascular endothelial cells than with non-brain endothelial cells. In addition, human brain microvascular endothelial cells maintained their morphology and intercellular junctional resistance in response to E. coli K1. In contrast, non-brain endothelial cells exhibited decreased transendothelial electrical resistance and detachment from the matrix upon exposure to E. coli K1. These different responses of brain and non-brain endothelial cells to E. coli K1 may form the basis of E. coli K1's propensity to cause meningitis.
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Affiliation(s)
- Maneesh Paul-Satyaseela
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, 600 North Wolfe St., Park 256, Baltimore, MD 21287, USA.
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23
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Ray PE, Soler-García AA, Xu L, Soderland C, Blumenthal R, Puri A. Fusion of HIV-1 envelope-expressing cells to human glomerular endothelial cells through an CXCR4-mediated mechanism. Pediatr Nephrol 2005; 20:1401-9. [PMID: 16047221 DOI: 10.1007/s00467-005-1950-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2004] [Revised: 03/10/2005] [Accepted: 03/15/2005] [Indexed: 11/25/2022]
Abstract
A central question in the pathogenesis of HIV-associated thrombotic microangiopathic (HIV-TMA) lesions is whether the HIV-1 envelope glycoprotein (HIV-1 Env) can interact directly with human glomerular endothelial cells (HGECs) through specific HIV-1 co-receptors. The goal of this study was to determine whether cultured primary HGECs express significant levels of the major HIV-1 co-receptors CD4, CXCR4, and/or CCR5 to allow fusion interactions with HIV-1. The expression of CD4, CXCR-4 and CCR-5 was assessed in cultured HGECs by reverse transcriptase-polymerase chain reaction (RT-PCR) and flow cytometry using specific antibodies. The HIV-1 Env-mediated membrane fusion of target glomerular cells was evaluated by a fluorescent dye transfer-based cell-cell fusion microscopic method. HGECs express CXCR4 mRNA and protein as determined by RT-PCR and immunostaining with phycoerythrin-conjugated anti-CXCR4 Mab 12G5. CD4 and CCR5 were not detected in HGECs, either by RT-PCR or by surface immunostaining with specific antibodies. Incubation of HGECs with cells expressing a CD4-independent envelope strain (HIV-1IIIB-8x) and the CD4-dependent envelope strain (HIV-1IIIB) resulted in transfer of fluorescent dyes of approximately 20% after 8-16 h incubation at 37 degrees C. Incubation in the presence of inhibitors (C34, which blocks six-helix bundle formation, and AMD3100, which interacts with CXCR4) reduced dye transfer by 60%-80%, confirming that the dye transfer was specific with respect to gp120-gp41-mediated fusion. Cultured primary HGECs express CXCR4 but not CD4 or CCR5. The ability of HGECs to promote fusion by a CD4-independent HIV-1 envelope glycoprotein suggests that these cells may become a potential direct target of certain HIV-1 isolates.
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Affiliation(s)
- Patricio E Ray
- Division of Nephrology and Center for Genetic Medicine, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA.
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24
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Chang YC, Stins MF, McCaffery MJ, Miller GF, Pare DR, Dam T, Paul-Satyaseela M, Kim KS, Kwon-Chung KJ, Paul-Satyasee M. Cryptococcal yeast cells invade the central nervous system via transcellular penetration of the blood-brain barrier. Infect Immun 2004; 72:4985-95. [PMID: 15321990 PMCID: PMC517459 DOI: 10.1128/iai.72.9.4985-4995.2004] [Citation(s) in RCA: 192] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cryptococcal meningoencephalitis develops as a result of hematogenous dissemination of inhaled Cryptococcus neoformans from the lung to the brain. The mechanism(s) by which C. neoformans crosses the blood-brain barrier (BBB) is a key unresolved issue in cryptococcosis. We used both an in vivo mouse model and an in vitro model of the human BBB to investigate the cryptococcal association with and traversal of the BBB. Exposure of human brain microvascular endothelial cells (HBMEC) to C. neoformans triggered the formation of microvillus-like membrane protrusions within 15 to 30 min. Yeast cells of C. neoformans adhered to and were internalized by the HBMEC, and they crossed the HBMEC monolayers via a transcellular pathway without affecting the monolayer integrity. The histopathology of mouse brains obtained after intravenous injection of C. neoformans showed that the yeast cells either were associated with endothelial cells or escaped from the brain capillary vessels into the neuropil by 3 h. C. neoformans was found in the brain parenchyma away from the vessels by 22 h. Association of C. neoformans with the choroid plexus, however, was not detected during up to 10 days of observation. Our findings indicate that C. neoformans cells invade the central nervous system by transcellular crossing of the endothelium of the BBB.
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Affiliation(s)
- Yun C Chang
- Molecular Microbiology Section, Laboratory of Clinical Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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25
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Callahan MK, Williams KA, Kivisäkk P, Pearce D, Stins MF, Ransohoff RM. CXCR3 marks CD4+ memory T lymphocytes that are competent to migrate across a human brain microvascular endothelial cell layer. J Neuroimmunol 2004; 153:150-7. [PMID: 15265673 DOI: 10.1016/j.jneuroim.2004.05.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2004] [Revised: 05/12/2004] [Accepted: 05/12/2004] [Indexed: 11/26/2022]
Abstract
Chemokines and their receptors may be implicated in leukocyte ingress into brain during inflammation observed during the course of multiple sclerosis (MS). To address receptor modulation on CD4+ memory T lymphocytes during diapedesis, we used an in vitro model of the blood-brain barrier (BBB). We found that only memory (CD45RO+) cells transmigrated and type 3 CXC chemokine receptor (CXCR3) was enriched on transmigrated cells. CXCR3 depletion of the input population did not affect transmigration capability. CXCR3 reemerged on CXCR3 depleted cells independently of endothelial cell exposure, but was susceptible to incubation at 4 degrees C, indicating receptor recycling. We propose that CXCR3 serves as a surface marker for cells that have the capacity to cross the BBB, but does not play an essential role in extravasation.
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Affiliation(s)
- Melissa K Callahan
- Department of Neurosciences, Cleveland Clinic Foundation, NC 30 Lerner Research Institute, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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Bissel SJ, Wiley CA. Human immunodeficiency virus infection of the brain: pitfalls in evaluating infected/affected cell populations. Brain Pathol 2004; 14:97-108. [PMID: 14997942 PMCID: PMC1449744 DOI: 10.1111/j.1750-3639.2004.tb00503.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Monocyte/macrophages and CD4 T-cells are the primary hematopoietic targets of productive HIV infection. In the brain, potential cellular targets for HIV infection include perivascular and parenchymal macrophages/microglia, oligodendrocytes, endothelia, neurons, and astrocytes. We examine evidence of productive and non-productive infection for each cell type in the brains of HIV-infected patients with and without HIV encephalitis. Despite the voluminous literature and substantial experimental effort over the past two decades, evidence for productive infection of any brain cell other than macrophages is left wanting.
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Affiliation(s)
- Stephanie J. Bissel
- Departments of Infectious Diseases and Microbiology and University of Pittsburgh, Pa
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27
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Khan NA, Di Cello F, Nath A, Kim KS. Human immunodeficiency virus type 1 tat-mediated cytotoxicity of human brain microvascular endothelial cells. J Neurovirol 2004; 9:584-93. [PMID: 14602571 DOI: 10.1080/13550280390218760] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
Abstract
Human immunodeficiency virus (HIV)-1 infection is often complicated with neurologic disorders, but the pathogenesis of HIV-1 encephalopathy is incompletely understood. Tat (HIV-1 transactivator protein) is released from HIV-1-infected cells and has been detected in the sera and cerebrospinal fluid of HIV-1-infected patients. Tat, along with increased inflammatory cytokines such as interferon-gamma (IFN-gamma), have been implicated in the pathogenesis of HIV-1-associated blood-brain barrier dysfunction. The present study examined the effects of Tat and IFN-gamma on human brain microvascular endothelial cells (HBMECs), which constitute the blood-brain barrier. Tat produced cytotoxicity of HBMECs, but required IFN-gamma. IFN-gamma treatment of HBMECs up-regulates vascular endothelial growth factor receptor-2 (VEGFR2/KDR), which is known to be the receptor for Tat. Tat activated KDR in the presence of IFN-gamma, and Tat-mediated cytopathic changes involve its interaction with KDR and phosphatidylinositol 3-kinase (PI3K). Further understanding and characterization of Tat-HBMEC interactions should help us understand HIV-1 neuropathogenesis and develop strategies to prevent HIV-1 encephalopathy.
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Affiliation(s)
- Naveed Ahmed Khan
- Division of Pediatric Infectious Diseases, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Erdreich-Epstein A, Tran LB, Bowman NN, Wang H, Cabot MC, Durden DL, Vlckova J, Reynolds CP, Stins MF, Groshen S, Millard M. Ceramide signaling in fenretinide-induced endothelial cell apoptosis. J Biol Chem 2002; 277:49531-7. [PMID: 12388538 DOI: 10.1074/jbc.m209962200] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Stress stimuli can mediate apoptosis by generation of the lipid second messenger, ceramide. Herein we investigate the molecular mechanism of ceramide signaling in endothelial apoptosis induced by fenretinide (N-(4-hydroxyphenyl)retinamide (4-HPR)). 4-HPR, a synthetic derivative of retinoic acid that induces ceramide in tumor cell lines, has been shown to have antiangiogenic effects, but the molecular mechanism of these is largely unknown. We report that 4-HPR was cytotoxic to endothelial cells (50% cytotoxicity at 2.4 microm, 90% at 5.36 microm) and induced a caspase-dependent endothelial apoptosis. 4-HPR (5 microm) increased ceramide levels in endothelial cells 5.3-fold, and the increase in ceramide was required to achieve the apoptotic effect of 4-HPR. The 4-HPR-induced increase in ceramide was suppressed by inhibitors of ceramide synthesis, fumonisin B(1), myriocin, and l-cycloserine, and 4-HPR transiently activated serine palmitoyltransferase, demonstrating that 4-HPR induced de novo ceramide synthesis. Sphingomyelin levels were not altered by 4-HPR, and desipramine had no effect on ceramide level, suggesting that sphingomyelinase did not contribute to the 4-HPR-induced ceramide increase. Finally, the pancaspase inhibitor, t-butyloxycarbonyl-aspartyl[O-methyl]-fluoromethyl ketone, suppressed 4-HPR-mediated apoptosis but not ceramide accumulation, suggesting that ceramide is upstream of caspases. Our results provide the first evidence that increased ceramide biosynthesis is required for 4-HPR-induced endothelial apoptosis and present a molecular mechanism for its antiangiogenic effects.
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Affiliation(s)
- Anat Erdreich-Epstein
- Division of Hematology-Oncology, Department of Pediatrics, Childrens Hospital Los Angeles, Keck School of Medicine, University of Southern California, 4650 Sunset Boulevard, Los Angeles, CA 90027, USA.
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Didier N, Banks WA, Créminon C, Dereuddre-Bosquet N, Mabondzo A. HIV-1-induced production of endothelin-1 in an in vitro model of the human blood-brain barrier. Neuroreport 2002; 13:1179-83. [PMID: 12151765 DOI: 10.1097/00001756-200207020-00022] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Evidence suggests that the HIV-1 envelope glycoproteins play a role in the central nervous system (CNS) complications of AIDS. Endothelin-1 (ET-1) has also been implicated in brain injury and the progression of the AIDS dementia complex (ADC). Here, we used a real-time reverse transcription polymerase chain reaction assay and an immunometric assay to show that in vitro model of the blood-brain barrier (BBB) consisting of a monolayer co-culture of astrocytes and human brain microvascular endothelial cells (A-HBMEC) increased its expression of ET-1 mRNA and secretion of ET-1 peptide when infected with HIV-1. The enhanced expression of ET-1 occurred independently of viral replication as it was also induced by the viral glycoprotein coat HIV-1g120SF. These results show that one mechanism by which HIV-1 might affect the CNS is by inducing release of ET-1 by the BBB.
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Affiliation(s)
- Nathalie Didier
- CEA, Laboratoire d'Etudes du Métabolisme des Médicaments, Service de Pharmacologie et d'Immunologie, DRM/DSV, Bâtiment 136, 91191 Gif sur Yvette, France
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