scholarly journals SARS-CoV-2 Spike Protein and Lung Vascular Cells

2020 ◽  
Vol 1 (1) ◽  
pp. 40-48
Author(s):  
Sri Jayalakshmi Suresh ◽  
Yuichiro Justin Suzuki
Keyword(s):  
Membrane Fusion ◽  
Viral Entry ◽  
Biological Effects ◽  
Spike Protein ◽  
Vascular Cells ◽  
Membrane Fusion Protein ◽  
Vascular Walls ◽  
Immunodeficiency Virus ◽  
Pulmonary Arterial

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing the current pandemic of coronavirus disease 2019 (COVID-19), and COVID-19 vaccines focus on its spike protein. However, in addition to facilitating the membrane fusion and viral entry, the SARS-CoV-2 spike protein promotes cell growth signaling in human lung vascular cells, and patients who have died of COVID-19 have thickened pulmonary vascular walls, linking the spike protein to a fatal disease, pulmonary arterial hypertension (PAH). In addition to SARS-CoV spike proteins, gp120, the viral membrane fusion protein of human immunodeficiency virus (HIV), has been reported to promote cell signaling, and long-term surviving HIV-positive patients have a high incidence of developing PAH. This article describes the findings of the SARS-CoV-2 spike protein affecting lung vascular cells and explains how the spike protein possibly increases the incidence of PAH. Since the SARS-CoV-2 spike protein will be administered to millions of people as COVID-19 vaccines, it is critical to understand the biological effects of this protein on human cells to ensure that it does not promote long-term adverse health consequences.

scholarly journals Conformational States of the Severe Acute Respiratory Syndrome Coronavirus Spike Protein Ectodomain

2006 ◽  
Vol 80 (14) ◽  
pp. 6794-6800 ◽  
Author(s):  
Fang Li ◽  
Marcelo Berardi ◽  
Wenhui Li ◽  
Michael Farzan ◽  
Philip R. Dormitzer ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Membrane Fusion ◽  
Receptor Binding ◽  
Conformational Changes ◽  
Viral Entry ◽  
Protein S ◽  
Spike Protein ◽  
Fusion Peptides ◽  
Conformational States ◽  
Protease Cleavage

ABSTRACT The severe acute respiratory syndrome coronavirus enters cells through the activities of a spike protein (S) which has receptor-binding (S1) and membrane fusion (S2) regions. We have characterized four sequential states of a purified recombinant S ectodomain (S-e) comprising S1 and the ectodomain of S2. They are S-e monomers, uncleaved S-e trimers, cleaved S-e trimers, and dissociated S1 monomers and S2 trimer rosettes. Lowered pH induces an irreversible transition from flexible, L-shaped S-e monomers to clove-shaped trimers. Protease cleavage of the trimer occurs at the S1-S2 boundary; an ensuing S1 dissociation leads to a major rearrangement of the trimeric S2 and to formation of rosettes likely to represent clusters of elongated, postfusion trimers of S2 associated through their fusion peptides. The states and transitions of S suggest conformational changes that mediate viral entry into cells.

scholarly journals A Small-molecule Inhibitor Directed against the Chemokine Receptor CXCR4 Prevents its Use as an HIV-1 Coreceptor

1997 ◽  
Vol 186 (8) ◽  
pp. 1395-1400 ◽  
Author(s):  
Benjamin J. Doranz ◽  
Kathie Grovit-Ferbas ◽  
Matthew P. Sharron ◽  
Si-Hua Mao ◽  
Matthew Bidwell Goetz ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Small Molecule ◽  
Chemokine Receptor ◽  
Viral Entry ◽  
Small Molecule Inhibitor ◽  
Chemokine Receptor Cxcr4 ◽  
Mechanism Of Inhibition ◽  
Molecule Inhibitor ◽  
Immunodeficiency Virus ◽  
Hiv 1

The chemokine receptor CXCR4 is the major coreceptor used for cellular entry by T cell– tropic human immunodeficiency virus (HIV)-1 strains, whereas CCR5 is used by macrophage (M)-tropic strains. Here we show that a small-molecule inhibitor, ALX40-4C, inhibits HIV-1 envelope (Env)-mediated membrane fusion and viral entry directly at the level of coreceptor use. ALX40-4C inhibited HIV-1 use of the coreceptor CXCR4 by T- and dual-tropic HIV-1 strains, whereas use of CCR5 by M- and dual-tropic strains was not inhibited. Dual-tropic viruses capable of using both CXCR4 and CCR5 were inhibited by ALX40-4C only when cells expressed CXCR4 alone. ALX40-4C blocked stromal-derived factor (SDF)-1α–mediated activation of CXCR4 and binding of the monoclonal antibody 12G5 to cells expressing CXCR4. Overlap of the ALX40-4C binding site with that of 12G5 and SDF implicates direct blocking of Env interactions, rather than downregulation of receptor, as the mechanism of inhibition. Thus, ALX40-4C represents a small-molecule inhibitor of HIV-1 infection that acts directly against a chemokine receptor at the level of Env-mediated membrane fusion.

scholarly journals Current Perspectives in the Discovery of Newer Medications Against the Outbreak of COVID-19

2021 ◽  
Vol 8 ◽  
Author(s):  
M. Ramesh ◽  
Krishnan Anand ◽  
Mohd Shahbaaz ◽  
Magda H. Abdellattif
Keyword(s):  
Small Molecules ◽  
Viral Entry ◽  
Respiratory Illness ◽  
Disease Outbreak ◽  
Spike Protein ◽  
Severe Illness ◽  
Human Lungs ◽  
Synthetic Approaches ◽  
Severe Respiratory Illness

A rapid and increasing spread of COVID-19 pandemic disease has been perceived worldwide in 2020. The current COVID-19 disease outbreak is due to the spread of SARS-CoV-2. SARS-CoV-2 is a new strain of coronavirus that has spike protein on the envelope. The spike protein of the virus binds with the ACE-2 receptor of the human lungs surface for entering into the host. Therefore, the blocking of viral entry into the host by targeting the spike protein has been suggested to be a valid strategy to treat COVID-19. The patients of COVID-19 were found to be asymptomatic, cold, mild to severe respiratory illness, and leading to death. The severe illness has been noted mainly in old age people, cardiovascular disease patients, and respiratory disease patients. However, the long-term health effects due to COVID-19 are not yet known. Recently, the vaccines were authorized to protect from COVID-19. However, the researchers have put an effort to discover suitable targets and newer medications in the form of small molecules or peptides, based on in-silico methods and synthetic approaches. This manuscript describes the current perspectives of the causative agent, diagnostic procedure, therapeutic targets, treatment, clinical trials, and development of potential clinical candidates of COVID-19. The study will be useful to identify the potential newer medications for the treatment of COVID-19.

scholarly journals Dependence of Golgi apparatus integrity on nitric oxide in vascular cells: implications in pulmonary arterial hypertension

2011 ◽  
Vol 300 (4) ◽  
pp. H1141-H1158 ◽  
Author(s):  
Jason E. Lee ◽  
Kirit Patel ◽  
Sharilyn Almodóvar ◽  
Rubin M. Tuder ◽  
Sonia C. Flores ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Pulmonary Arterial Hypertension ◽  
Golgi Apparatus ◽  
Arterial Hypertension ◽  
Vascular Cells ◽  
Immunodeficiency Virus ◽  
Pulmonary Arterial ◽  
Golgi Fragmentation ◽  
In Cells

Although reduced bioavailability of nitric oxide (NO) has been implicated in the pathogenesis of pulmonary arterial hypertension (PAH), its consequences on organellar structure and function within vascular cells is largely unexplored. We investigated the effect of reduced NO on the structure of the Golgi apparatus as assayed by giantin or GM130 immunofluorescence in human pulmonary arterial endothelial (HPAECs) and smooth muscle (HPASMCs) cells, bovine PAECs, and human EA.hy926 endothelial cells. Golgi structure was also investigated in cells in tissue sections of pulmonary vascular lesions in idiopathic PAH (IPAH) and in macaques infected with a chimeric simian immunodeficiency virus containing the human immunodeficiency virus (HIV)- nef gene (SHIV- nef) with subcellular three-dimensional (3D) immunoimaging. Compounds with NO scavenging activity including 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO), methylene blue, N-acetylcysteine, and hemoglobin markedly fragmented the Golgi in all cell types evaluated as did monocrotaline pyrrole, while LY-83583, sildenafil, fasudil, Y-27632, Tiron, Tempol, or H2O2did not. Golgi fragmentation by NO scavengers was inhibited by diethylamine NONOate, was evident in HPAECs after selective knockdown of endothelial nitric oxide synthase using small interfering RNA (siRNA), was independent of microtubule organization, required the GTPase dynamin 2, and was accompanied by depletion of α-soluble N-ethylmaleimide-sensitive factor (NSF) acceptor protein (α-SNAP) from Golgi membranes and codispersal of the SNAP receptor (SNARE) Vti1a with giantin. Golgi fragmentation was confirmed in endothelial and smooth muscle cells in pulmonary arterial lesions in IPAH and the SHIV- nef-infected macaque with subcellular 3D immunoimaging. In SHIV- nef-infected macaques Golgi fragmentation was observed in cells containing HIV-nef-bearing endosomes. The observed Golgi fragmentation suggests that NO plays a significant role in modulating global protein trafficking patterns that contribute to changes in the cell surface landscape and functional signaling in vascular cells.

scholarly journals Golgi dysfunction is a common feature in idiopathic human pulmonary hypertension and vascular lesions in SHIV-nef-infected macaques

2009 ◽  
Vol 297 (4) ◽  
pp. L729-L737 ◽  
Author(s):  
Pravin B. Sehgal ◽  
Somshuvra Mukhopadhyay ◽  
Kirit Patel ◽  
Fang Xu ◽  
Sharilyn Almodóvar ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Human Lung ◽  
Matrix Proteins ◽  
Vascular Lesions ◽  
Vascular Cells ◽  
Human Lung Tissue ◽  
Macaque Model ◽  
Plexiform Lesions ◽  
Immunodeficiency Virus ◽  
Pulmonary Arterial

Golgi dysfunction has been previously investigated as a mechanism involved in monocrotaline-induced pulmonary hypertension (PAH). In the present study, we addressed whether Golgi dysfunction might occur in pulmonary vascular cells in idiopathic PAH (IPAH) and whether there might be a causal relationship between trafficking dysfunction and vasculopathies of PAH. Quantitative immunostaining for the Golgi tethers giantin and p115 on human lung tissue from patients with IPAH ( n = 6) compared with controls demonstrated a marked cytoplasmic dispersal of giantin- and p115-bearing vesicular elements in vascular cells in the proliferative, obliterative, and plexiform lesions in IPAH and an increase in the amounts of these Golgi tethers/matrix proteins per cell. The causality question was approached by genetic means using human immunodeficiency virus (HIV)-Nef, a protein that disrupts endocytic and trans-Golgi trafficking. Macaques infected with a chimeric simian immunodeficiency virus (SIV) containing the HIV- nef gene (SHIV- nef), but not the nonchimeric SIV virus containing the endogenous SIV- nef gene, displayed pulmonary arterial vasculopathies similar to those in human IPAH. Giantin and p115 levels and their subcellular distribution in pulmonary vascular cells in lungs of SHIV- nef infected macaques ( n = 4) were compared with SIV-infected ( n = 3) and an uninfected macaque control. Only macaques infected with chimeric SHIV- nef showed pulmonary vascular lesions containing cells with dramatic cytoplasmic dispersal and an increase in giantin and p115. Specifically, the HIV-Nef-positive cells showed increased giantin, p115, and the activated transcription factor PY-STAT3. These data represent the first test of the Golgi dysfunction hypothesis in IPAH and place trafficking and Golgi disruption in the chain of causality of pulmonary vasculopathies in the macaque model.

scholarly journals Structural impact on SARS-CoV-2 spike protein by D614G substitution

Science ◽  
2021 ◽  
pp. eabf2303
Author(s):  
Jun Zhang ◽  
Yongfei Cai ◽  
Tianshu Xiao ◽  
Jianming Lu ◽  
Hanqin Peng ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Membrane Fusion ◽  
Receptor Binding ◽  
Viral Entry ◽  
Vaccine Development ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Structural Rearrangements ◽  
Viral Spread ◽  
Structural Impact

Substitution for aspartic acid by glycine at position 614 in the spike (S) protein of severe acute respiratory syndrome coronavirus 2 appears to facilitate rapid viral spread. The G614 strain and its recent variants are now the dominant circulating forms. We report here cryo-EM structures of a full-length G614 S trimer, which adopts three distinct prefusion conformations differing primarily by the position of one receptor-binding domain. A loop disordered in the D614 S trimer wedges between domains within a protomer in the G614 spike. This added interaction appears to prevent premature dissociation of the G614 trimer, effectively increasing the number of functional spikes and enhancing infectivity, and to modulate structural rearrangements for membrane fusion. These findings extend our understanding of viral entry and suggest an improved immunogen for vaccine development.

scholarly journals Identification of the LWYIK Motif Located in the Human Immunodeficiency Virus Type 1 Transmembrane gp41 Protein as a Distinct Determinant for Viral Infection

2008 ◽  
Vol 83 (2) ◽  
pp. 870-883 ◽  
Author(s):  
Steve S.-L. Chen ◽  
Polung Yang ◽  
Po-Yuan Ke ◽  
Hsiao-Fen Li ◽  
Woan-Eng Chan ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Membrane Fusion ◽  
Lipid Rafts ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Viral Entry ◽  
Cell Surface Expression ◽  
Immunodeficiency Virus

ABSTRACT The highly conserved LWYIK motif located immediately proximal to the membrane-spanning domain of the gp41 transmembrane protein of human immunodeficiency virus type 1 has been proposed as being important for the surface envelope (Env) glycoprotein's association with lipid rafts and gp41-mediated membrane fusion. Here we employed substitution and deletion mutagenesis to understand the role of this motif in the virus life cycle. None of the mutants examined affected the synthesis, precursor processing, CD4 binding, oligomerization, or cell surface expression of the Env, nor did they alter Env incorporation into the virus. All of the mutants, particularly the ΔYI, ΔIK, and ΔLWYIK mutants, in which the indicated residues were deleted, exhibited greatly reduced one-cycle viral replication and the Env trans-complementation ability. All of these deletion mutant proteins were still localized in the lipid rafts. With the exception of the Trp-to-Ala (WA) mutant, which exhibited reduced viral infectivity albeit with normal membrane fusion, all mutants displayed loss of some or almost all of the membrane fusion ability. Although these deletion mutants partially inhibited in trans wild-type (WT) Env-mediated fusion, they were more effective in dominantly interfering with WT Env-mediated viral entry when coexpressed with the WT Env, implying a role of this motif in postfusion events as well. Both T20 and L43L peptides derived from the two gp41 extracellular C- and N-terminal α-helical heptad repeats, respectively, inhibited WT and ΔLWYIK Env-mediated viral entry with comparable efficacies. Biotin-tagged T20 effectively captured both the fusion-active, prehairpin intermediates of WT and mutant gp41 upon CD4 activation. Env without the deletion of the LWYIK motif still effectively mediated lipid mixing but inhibited content mixing. Our study demonstrates that the immediate membrane-proximal LWYIK motif acts as a unique and distinct determinant located in the gp41 C-terminal ectodomain by promoting enlargement of fusion pores and postfusion activities.

scholarly journals Domains and Functions of Spike Protein in SARS-Cov-2 in the Context of Vaccine Design

Viruses ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 109
Author(s):  
Xuhua Xia
Keyword(s):  
Membrane Fusion ◽  
Receptor Binding ◽  
Viral Entry ◽  
Vaccine Development ◽  
Cell Entry ◽  
Spike Protein ◽  
Structural Domains ◽  
Theoretical Approaches ◽  
A Cell ◽  
And Function

The spike protein in SARS-CoV-2 (SARS-2-S) interacts with the human ACE2 receptor to gain entry into a cell to initiate infection. Both Pfizer/BioNTech’s BNT162b2 and Moderna’s mRNA-1273 vaccine candidates are based on stabilized mRNA encoding prefusion SARS-2-S that can be produced after the mRNA is delivered into the human cell and translated. SARS-2-S is cleaved into S1 and S2 subunits, with S1 serving the function of receptor-binding and S2 serving the function of membrane fusion. Here, I dissect in detail the various domains of SARS-2-S and their functions discovered through a variety of different experimental and theoretical approaches to build a foundation for a comprehensive mechanistic understanding of how SARS-2-S works to achieve its function of mediating cell entry and subsequent cell-to-cell transmission. The integration of structure and function of SARS-2-S in this review should enhance our understanding of the dynamic processes involving receptor binding, multiple cleavage events, membrane fusion, viral entry, as well as the emergence of new viral variants. I highlighted the relevance of structural domains and dynamics to vaccine development, and discussed reasons for the spike protein to be frequently featured in the conspiracy theory claiming that SARS-CoV-2 is artificially created.

scholarly journals SARS-CoV-2 spike protein-mediated cell signaling in lung vascular cells

2020 ◽  
Author(s):  
Yuichiro J. Suzuki ◽  
Sofia I. Nikolaienko ◽  
Vyacheslav A. Dibrova ◽  
Yulia V. Dibrova ◽  
Volodymyr M. Vasylyk ◽  
...  
Keyword(s):  
Cell Growth ◽  
Pulmonary Artery ◽  
Cell Signaling ◽  
Host Cells ◽  
Spike Protein ◽  
Vascular Cells ◽  
Angiotensin Converting Enzyme 2 ◽  
Vascular Walls ◽  
Human Pulmonary Artery ◽  
Viral Components

AbstractCurrently, the world is suffering from the pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that uses angiotensin-converting enzyme 2 (ACE2) as a receptor to enter the host cells. So far, 30 million people have been infected with SARS-CoV-2, and nearly 1 million people have died because of COVID-19 worldwide, causing serious health, economical, and sociological problems. However, the mechanism of the effect of SARS-CoV-2 on human host cells has not been defined. The present study reports that the SARS-CoV-2 spike protein alone without the rest of the viral components is sufficient to elicit cell signaling in lung vascular cells. The treatment of human pulmonary artery smooth muscle cells or human pulmonary artery endothelial cells with recombinant SARS-CoV-2 spike protein S1 subunit (Val16 – Gln690) at 10 ng/ml (0.13 nM) caused an activation of MEK phosphorylation. The activation kinetics was transient with a peak at 10 min. The recombinant protein that contains only the ACE2 receptor-binding domain of SARS-CoV-2 spike protein S1 subunit (Arg319 – Phe541), on the other hand, did not cause this activation. Consistent with the activation of cell growth signaling in lung vascular cells by SARS-CoV-2 spike protein, pulmonary vascular walls were found to be thickened in COVID-19 patients. Thus, SARS-CoV-2 spike protein-mediated cell growth signaling may participate in adverse cardiovascular/pulmonary outcomes, and this mechanism may provide new therapeutic targets to combat COVID-19.

Sign in / Sign up

Export Citation Format

Share Document