scholarly journals Expression of SARS-CoV-2-related receptors in cells of the neurovascular unit: implications for HIV-1 infection

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Silvia Torices ◽  
Rosalba Cabrera ◽  
Michael Stangis ◽  
Oandy Naranjo ◽  
Nikolai Fattakhov ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Expression Pattern ◽  
Cathepsin L ◽  
Neurovascular Unit ◽  
Neurological Complications ◽  
Protein Subunit ◽  
Gene And Protein Expression ◽  
Direct Binding ◽  
Infected Cells ◽  
Hiv 1

Abstract Background Neurological complications are common in patients affected by COVID-19 due to the ability of SARS-CoV-2 to infect brains. While the mechanisms of this process are not fully understood, it has been proposed that SARS-CoV-2 can infect the cells of the neurovascular unit (NVU), which form the blood-brain barrier (BBB). The aim of the current study was to analyze the expression pattern of the main SARS-CoV-2 receptors in naïve and HIV-1-infected cells of the NVU in order to elucidate a possible pathway of the virus entry into the brain and a potential modulatory impact of HIV-1 in this process. Methods The gene and protein expression profile of ACE2, TMPRSS2, ADAM17, BSG, DPP4, AGTR2, ANPEP, cathepsin B, and cathepsin L was assessed by qPCR, immunoblotting, and immunostaining, respectively. In addition, we investigated if brain endothelial cells can be affected by the exposure to the S1 subunit of the S protein, the domain responsible for the direct binding of SARS-CoV-2 to the ACE2 receptors. Results The receptors involved in SARS-CoV-2 infection are co-expressed in the cells of the NVU, especially in astrocytes and microglial cells. These receptors are functionally active as exposure of endothelial cells to the SARS CoV-2 S1 protein subunit altered the expression pattern of tight junction proteins, such as claudin-5 and ZO-1. Additionally, HIV-1 infection upregulated ACE2 and TMPRSS2 expression in brain astrocytes and microglia cells. Conclusions These findings provide key insight into SARS-CoV-2 recognition by cells of the NVU and may help to develop possible treatment of CNS complications of COVID-19.

scholarly journals Expression of SARS-CoV-2-related Receptors in Cells of the Neurovascular Unit: Implications for HIV-1 Infection

2021 ◽  
Author(s):  
Silvia Torices ◽  
Rosalba Cabrera ◽  
Michael Stangis ◽  
Oandy Naranjo ◽  
Daniel Adesse ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Expression Pattern ◽  
Cathepsin L ◽  
Neurovascular Unit ◽  
Neurological Complications ◽  
Protein Subunit ◽  
Gene And Protein Expression ◽  
Direct Binding ◽  
Infected Cells ◽  
Hiv 1

Abstract Background. Neurological complications are common in patients affected by COVID-19 due to the ability of SARS-CoV-2 to infect brains. While the mechanisms of this process are not fully understood, it has been proposed that SARS-CoV-2 can infect the cells of the neurovascular units (NVU), which form the blood-brain barrier (BBB). The aim of the current study was to analyze the expression pattern of the main SARS-CoV-2 receptors in naïve and HIV-1-infected cells of the NVU in order to elucidate a possible pathway of the virus entry into the brain and a potential modulatory impact of HIV-1 in this process. Methods. The gene and protein expression profile of ACE2, TMPRSS2, ADAM17, BSG, DPP4, AGTR2, ANPEP, cathepsin B and cathepsin L was assessed by qPCR and immunoblotting, respectively. In addition, we investigated if brain endothelial cells can be affected by the exposure to the S1 subunit of the S protein, the domain responsible for the direct binding of SARS-CoV-2 to the ACE2 receptors. Results. The receptors involved in SARS-CoV-2 infection are coexpressed in the cells of the NVU, especially in astrocytes and microglial cells. These receptors are functionally active as exposure of endothelial cells to the SARS CoV-2 S1 protein subunit altered the expression pattern of tight junction proteins, such as claudin-5 and ZO-1. Additionally, HIV-1 infection upregulated ACE2 and TMPRSS2 expression in brain astrocytes and microglia cells.Conclusions. These findings provide key insight into SARS-CoV-2 recognition by cells of the NVU and may help to develop possible treatment of CNS complications of COVID-19.

scholarly journals Dysfunction of brain pericytes in chronic neuroinflammation

2015 ◽  
Vol 36 (4) ◽  
pp. 794-807 ◽  
Author(s):  
Yuri Persidsky ◽  
Jeremy Hill ◽  
Ming Zhang ◽  
Holly Dykstra ◽  
Malika Winfield ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Human Brain ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Neurovascular Unit ◽  
Brain Endothelial Cells ◽  
Monocyte Migration ◽  
Brain Pericytes ◽  
Hiv 1

Brain pericytes are uniquely positioned within the neurovascular unit to provide support to blood brain barrier (BBB) maintenance. Neurologic conditions, such as HIV-1-associated neurocognitive disorder, are associated with BBB compromise due to chronic inflammation. Little is known about pericyte dysfunction during HIV-1 infection. We found decreased expression of pericyte markers in human brains from HIV-1-infected patients (even those on antiretroviral therapy). Using primary human brain pericytes, we assessed expression of pericyte markers (α1-integrin, α-smooth muscle actin, platelet-derived growth factor-B receptor β, CX-43) and found their downregulation after treatment with tumor necrosis factor-α (TNFα) or interleukin-1 β (IL-1β). Pericyte exposure to virus or cytokines resulted in decreased secretion of factors promoting BBB formation (angiopoietin-1, transforming growth factor-β1) and mRNA for basement membrane components. TNFα and IL-1β enhanced expression of adhesion molecules in pericytes paralleling increased monocyte adhesion to pericytes. Monocyte migration across BBB models composed of human brain endothelial cells and pericytes demonstrated a diminished rate in baseline migration compared to constructs composed only of brain endothelial cells. However, exposure to the relevant chemokine, CCL2, enhanced the magnitude of monocyte migration when compared to BBB models composed of brain endothelial cells only. These data suggest an important role of pericytes in BBB regulation in neuroinflammation.

scholarly journals HIV-1 and Amyloid Beta Remodel Proteome of Brain Endothelial Extracellular Vesicles

2020 ◽  
Vol 21 (8) ◽  
pp. 2741
Author(s):  
Ibolya E. András ◽  
Brice B. Sewell ◽  
Michal Toborek
Keyword(s):  
Endothelial Cells ◽  
Extracellular Vesicles ◽  
Amyloid Beta ◽  
Neurovascular Unit ◽  
Brain Exposure ◽  
Unit Cells ◽  
The Brain ◽  
Insight Into ◽  
Hiv 1 ◽  
Pathway Networks

Amyloid beta (Aβ) depositions are more abundant in HIV-infected brains. The blood–brain barrier, with its backbone created by endothelial cells, is assumed to be a core player in Aβ homeostasis and may contribute to Aβ accumulation in the brain. Exposure to HIV increases shedding of extracellular vesicles (EVs) from human brain endothelial cells and alters EV-Aβ levels. EVs carrying various cargo molecules, including a complex set of proteins, can profoundly affect the biology of surrounding neurovascular unit cells. In the current study, we sought to examine how exposure to HIV, alone or together with Aβ, affects the surface and total proteomic landscape of brain endothelial EVs. By using this unbiased approach, we gained an unprecedented, high-resolution insight into these changes. Our data suggest that HIV and Aβ profoundly remodel the proteome of brain endothelial EVs, altering the pathway networks and functional interactions among proteins. These events may contribute to the EV-mediated amyloid pathology in the HIV-infected brain and may be relevant to HIV-1-associated neurocognitive disorders.

scholarly journals Cathepsin L Acutely Alters Microvessel Integrity within the Neurovascular Unit during Focal Cerebral Ischemia

2015 ◽  
Vol 35 (11) ◽  
pp. 1888-1900 ◽  
Author(s):  
Yu-Huan Gu ◽  
Masato Kanazawa ◽  
Stephanie Y Hung ◽  
Xiaoyun Wang ◽  
Shunichi Fukuda ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cerebral Ischemia ◽  
Ex Vivo ◽  
Focal Cerebral Ischemia ◽  
Cathepsin L ◽  
Neurovascular Unit ◽  
Edema Formation ◽  
Ischemic Core ◽  
Neuron Injury

During focal cerebral ischemia, the degradation of microvessel basal lamina matrix occurs acutely and is associated with edema formation and microhemorrhage. These events have been attributed to matrix metalloproteinases (MMPs). However, both known protease generation and ligand specificities suggest other participants. Using cerebral tissues from a non-human primate focal ischemia model and primary murine brain endothelial cells, astrocytes, and microglia in culture, the effects of active cathepsin L have been defined. Within 2 hours of ischemia onset cathepsin L, but not cathepsin B, activity appears in the ischemic core, around microvessels, within regions of neuron injury and cathepsin L expression. In in vitro studies, cathepsin L activity is generated during experimental ischemia in microglia, but not astrocytes or endothelial cells. In the acidic ischemic core, cathepsin L release is significantly increased with time. A novel ex vivo assay showed that cathepsin L released from microglia during ischemia degrades microvessel matrix, and interacts with MMP activity. Hence, the loss of microvessel matrix during ischemia is explained by microglial cathepsin L release in the acidic core during injury evolution. The roles of cathepsin L and its interactions with specific MMP activities during ischemia are relevant to strategies to reduce microvessel injury and hemorrhage.

scholarly journals Inhibition of telomerase activity alters tight junction protein expression and induces transendothelial migration of HIV-1-infected cells

2010 ◽  
Vol 298 (4) ◽  
pp. H1136-H1145 ◽  
Author(s):  
Wen Huang ◽  
Geun Bae Rha ◽  
Lei Chen ◽  
Melissa J. Seelbach ◽  
Bei Zhang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tight Junction ◽  
Transendothelial Migration ◽  
Telomerase Activity ◽  
Brain Endothelial Cells ◽  
Tight Junction Proteins ◽  
Junction Protein ◽  
Infected Cells ◽  
Hiv 1 ◽  
Junction Proteins

Telomerase, via its catalytic component telomerase reverse transcriptase (TERT), extends telomeres of eukaryotic chromosomes. The importance of this reaction is related to the fact that telomere shortening is a rate-limiting mechanism for human life span that induces cell senescence and contributes to the development of age-related pathologies. The aim of the present study was to evaluate whether the modulation of telomerase activity can influence human immunodeficiency virus type 1 (HIV-1)-mediated dysfunction of human brain endothelial cells (hCMEC/D3 cells) and transendothelial migration of HIV-1-infected cells. Telomerase activity was modulated in hCMEC/D3 cells via small interfering RNA-targeting human TERT (hTERT) or by using a specific pharmacological inhibitor of telomerase, TAG-6. The inhibition of hTERT resulted in the upregulation of HIV-1-induced overexpression of intercellular adhesion molecule-1 via the nuclear factor-κB-regulated mechanism and induced the transendothelial migration of HIV-1-infected monocytic U937 cells. In addition, the blocking of hTERT activity potentiated a HIV-induced downregulation of the expression of tight junction proteins. These results were confirmed in TERT-deficient mice injected with HIV-1-specific protein Tat into the cerebral vasculature. Further studies revealed that the upregulation of matrix metalloproteinase-9 is the underlying mechanisms of disruption of tight junction proteins in hCMEC/D3 cells with inhibited TERT and exposed to HIV-1. These results indicate that the senescence of brain endothelial cells may predispose to the HIV-induced upregulation of inflammatory mediators and the disruption of the barrier function at the level of the brain endothelium.

scholarly journals Barrier-to-Autointegration Factor BAF Binds p55 Gagand Matrix and Is a Host Component of Human ImmunodeficiencyVirus Type 1Virions

2003 ◽  
Vol 77 (24) ◽  
pp. 13084-13092 ◽  
Author(s):  
Malini Mansharamani ◽  
David R. M. Graham ◽  
Daphne Monie ◽  
Kenneth K. Lee ◽  
James E. K. Hildreth ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Leukemia Virus ◽  
Moloney Murine Leukemia Virus ◽  
Blood Leukocytes ◽  
Target Dna ◽  
Direct Binding ◽  
Infected Cells ◽  
Hiv 1 ◽  
Host Component

ABSTRACT Barrier-to-autointegration factor (BAF) is a conserved human chromatin protein exploited by retroviruses. Previous investigators showed that BAF binds double-stranded DNA nonspecifically and is a host component of preintegration complexes (PICs) isolated from cells infected with human immunodeficiency virus type 1 (HIV-1) or Moloney murine leukemia virus. BAF protects PIC structure and stimulates the integration of salt-stripped PICs into target DNA in vitro. PICs are thought to acquire BAF from the cytoplasm during infection. However, we identified two human tissues (of 16 tested) in which BAF mRNA was not detected: thymus and peripheral blood leukocytes, which are enriched in CD4+ T lymphocytes and macrophage precursors, respectively. BAF protein was detected in activated but not resting CD4+ T lymphocytes; thus, if BAF were essential for PIC function, we hypothesized that virions might “bring their own BAF.” Supporting this model, BAF copurified with HIV-1 virions that were digested with subtilisin to remove microvesicle contaminants, and BAF was present in approximately zero to three copies per virion. In three independent assays, BAF bound directly to both p55 Gag (the structural precursor of HIV-1 virions) and its cleaved product, matrix. Using lysates from cells overexpressing Gag, endogenous BAF and Gag were coimmunoprecipitated by antibodies against Gag. Purified recombinant BAF had low micromolar affinities (1.1 to 1.4μ M) for recombinant Gag and matrix. We conclude that BAF is present at low levels in incoming virions, in addition to being acquired from the cytoplasm of newly infected cells. We further conclude that BAF might contribute to the assembly or activity of HIV-1 PICs through direct binding to matrix, as well as DNA.

HIV Envelope Protein gp120 Stimulates Expression of Specific Chemokines in Lymphatic Endothelial Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3102-3102
Author(s):  
Xuefeng Zhang ◽  
Jian Feng Wang ◽  
Jerome E. Groopman
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Immune Cell ◽  
Cell Trafficking ◽  
Lymphatic Endothelial Cells ◽  
Infected Cells ◽  
Hiv Envelope ◽  
Hiv 1

Abstract Lymphoid organs are the major anatomical home of HIV, where the virus replicates during both the acute and chronic phases of infections. In this regard, there are significantly more infected cells in lymph nodes (LNs) than in circulating blood, and these infected cells are a major reservoir of infectious HIV. Certain chemokines like CCL19 (MIP-3β) and CCL21 (SLC) play key roles in immune cell trafficking to LNs. They induce specific homing of naïve T cells and dendritic cells into the T cell zone of secondary lymphoid organs. There, the T cells become activated by the dendritic cells. A network of channels composed of lymphatic endothelium exists in LNs that provides a route for this dendritic cell and T cell movement. To date, how this lymphatic endothelium may contribute to the pathogenesis of HIV infection has not been studied. This prompted us to investigate whether HIV may alter immune cell trafficking via interaction with this lymphatic network. Lymphatic endothelial cells (LEC) were separated from primary dermal microvascular endothelial cells. The phenotype of LEC was confirmed by immunostaining with specific lymphatic markers including VEGFR-3, LYVE-1, and podoplanin. Since HIV envelope proteins are presented to endothelial cells in the microenvironment, we studied the effects of X4 gp120 on LEC. Using a pathway specific cDNA array, we detected enhanced expression of a restricted repertoire of chemokines in LEC upon HIV-1 gp120 stimulation. Gp120 upregulated expression of the chemokine genes GRO-α, GRO-γ, MIP-3β, and SDF-1α and β in LEC. These chemokines can act to enhance T cell and dendritic cell homing to LNs. Furthermore, we also detected GRO-α, SDF-1, and SLC proteins in culture supernatants of the gp120-treated LEC. We did not observe upregulation of the chemokines RANTES and MCP-1 upon gp120 stimulation. Since dendritic cells mediate the HIV infectivity of CD4+ T cells by presenting HIV particles, our study suggests that HIV-1 gp120-induced production of a restricted repertoire of chemokines in LEC may accelerate the trafficking of infected dendritic cells to LNs and foster HIV infection in this reservoir.

Resveratrol Reduces Matrix Metalloproteinase-2 Activity Induced by Oxygen-Glucose Deprivation and Reoxygenation in Human Cerebral Microvascular Endothelial Cells

2012 ◽  
Vol 82 (4) ◽  
pp. 267-274 ◽  
Author(s):  
Zahide Cavdar ◽  
Mehtap Y. Egrilmez ◽  
Zekiye S. Altun ◽  
Nur Arslan ◽  
Nilgun Yener ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Neurovascular Unit ◽  
Glucose Deprivation ◽  
Matrix Metalloproteinase 2 ◽  
Microvascular Endothelial Cells ◽  
Oxygen Glucose Deprivation ◽  
Microvascular Endothelial

The main pathophysiology in cerebral ischemia is the structural alteration in the neurovascular unit, coinciding with neurovascular matrix degradation. Among the human matrix metalloproteinases (MMPs), MMP-2 and -9, known as gelatinases, are the key enzymes for degrading type IV collagen, which is the major component of the basal membrane that surrounds the cerebral blood vessel. In the present study, we investigated the effects of resveratrol on cytotoxicity, reactive oxygen species (ROS), and gelatinases (MMP-2 and -9) in human cerebral microvascular endothelial cells exposed to 6 hours of oxygen-glucose deprivation and a subsequent 24 hours of reoxygenation with glucose (OGD/R), to mimic ischemia/reperfusion in vivo. Lactate dehydrogenase increased significantly, in comparison to that in the normoxia group. ROS was markedly increased in the OGD/R group, compared to normoxia. Correspondingly, ROS was significantly reduced with 50 μM of resveratrol. The proMMP-2 activity in the OGD/R group showed a statistically significant increase from the control cells. Resveratrol preconditioning decreased significantly the proMMP-2 in the cells exposed to OGD/R in comparison to that in the OGD/R group. Our results indicate that resveratrol regulates MMP-2 activity induced by OGD/R via its antioxidant effect, implying a possible mechanism related to the neuroprotective effect of resveratrol.

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