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1.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1867(6): 159139, 2022 06.
Article in English | MEDLINE | ID: covidwho-1719329

ABSTRACT

Pulmonary surfactant is a mixture of lipids and proteins, consisting of 90% phospholipid, and 10% protein by weight, found predominantly in pulmonary alveoli of vertebrate lungs. Two minor components of pulmonary surfactant phospholipids, phosphatidylglycerol (PG) and phosphatidylinositol (PI), are present within the alveoli at very high concentrations, and exert anti-inflammatory effects by regulating multiple Toll like receptors (TLR2/1, TLR4, and TLR2/6) by antagonizing cognate ligand-dependent activation. POPG also attenuates LPS-induced lung injury in vivo. In addition, these lipids bind directly to RSV and influenza A viruses (IAVs) and block interaction between host cells and virions, and thereby prevent viral replication in vitro. POPG and PI also inhibit RSV and IAV infection in vivo, in mice and ferrets. The lipids markedly inhibit SARS-CoV-2 infection in vitro. These findings suggest that both POPG and PI have strong potential to be applied as both prophylaxis and post-infection treatments for problematic respiratory viral infections.


Subject(s)
COVID-19 , Pulmonary Surfactants , Animals , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , COVID-19/drug therapy , Ferrets/metabolism , Lung/metabolism , Mice , Phospholipids/metabolism , Pulmonary Surfactants/metabolism , Pulmonary Surfactants/pharmacology , SARS-CoV-2 , Toll-Like Receptor 2
3.
Sci Rep ; 11(1): 22288, 2021 11 15.
Article in English | MEDLINE | ID: covidwho-1517638

ABSTRACT

Numerous repositioned drugs have been sought to decrease the severity of SARS-CoV-2 infection. It is known that among its physicochemical properties, Ursodeoxycholic Acid (UDCA) has a reduction in surface tension and cholesterol solubilization, it has also been used to treat cholesterol gallstones and viral hepatitis. In this study, molecular docking was performed with the SARS-CoV-2 Spike protein and UDCA. In order to confirm this interaction, we used Molecular Dynamics (MD) in "SARS-CoV-2 Spike protein-UDCA". Using another system, we also simulated MD with six UDCA residues around the Spike protein at random, naming this "SARS-CoV-2 Spike protein-6UDCA". Finally, we evaluated the possible interaction between UDCA and different types of membranes, considering the possible membrane conformation of SARS-CoV-2, this was named "SARS-CoV-2 membrane-UDCA". In the "SARS-CoV-2 Spike protein-UDCA", we found that UDCA exhibits affinity towards the central region of the Spike protein structure of - 386.35 kcal/mol, in a region with 3 alpha helices, which comprises residues from K986 to C1032 of each monomer. MD confirmed that UDCA remains attached and occasionally forms hydrogen bonds with residues R995 and T998. In the presence of UDCA, we observed that the distances between residues atoms OG1 and CG2 of T998 in the monomers A, B, and C in the prefusion state do not change and remain at 5.93 ± 0.62 and 7.78 ± 0.51 Å, respectively, compared to the post-fusion state. Next, in "SARS-CoV-2 Spike protein-6UDCA", the three UDCA showed affinity towards different regions of the Spike protein, but only one of them remained bound to the region between the region's heptad repeat 1 and heptad repeat 2 (HR1 and HR2) for 375 ps of the trajectory. The RMSD of monomer C was the smallest of the three monomers with a value of 2.89 ± 0.32, likewise, the smallest RMSF was also of the monomer C (2.25 ± 056). In addition, in the simulation of "SARS-CoV-2 membrane-UDCA", UDCA had a higher affinity toward the virion-like membrane; where three of the four residues remained attached once they were close (5 Å, to the centre of mass) to the membrane by 30 ns. However, only one of them remained attached to the plasma-like membrane and this was in a cluster of cholesterol molecules. We have shown that UDCA interacts in two distinct regions of Spike protein sequences. In addition, UDCA tends to stay bound to the membrane, which could potentially reduce the internalization of SARS-CoV-2 in the host cell.


Subject(s)
Antiviral Agents/metabolism , Drug Repositioning/methods , Lipid Bilayers/metabolism , Molecular Docking Simulation/methods , Phospholipids/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Ursodeoxycholic Acid/metabolism , Antiviral Agents/chemistry , COVID-19/metabolism , COVID-19/virology , Humans , Hydrogen Bonding , Membrane Fusion , Molecular Dynamics Simulation , Protein Binding , Protein Conformation, alpha-Helical , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Ursodeoxycholic Acid/chemistry , Virion/metabolism
4.
J Clin Invest ; 131(24)2021 12 15.
Article in English | MEDLINE | ID: covidwho-1495792

ABSTRACT

Acute COVID-19, caused by SARS-CoV-2, is characterized by diverse clinical presentations, ranging from asymptomatic infection to fatal respiratory failure, and often associated with varied longer-term sequelae. Over the past 18 months, it has become apparent that inappropriate immune responses contribute to the pathogenesis of severe COVID-19. Researchers working at the intersection of COVID-19 and autoimmunity recently gathered at an American Autoimmune Related Diseases Association Noel R. Rose Colloquium to address the current state of knowledge regarding two important questions: Does established autoimmunity predispose to severe COVID-19? And, at the same time, can SARS-CoV-2 infection trigger de novo autoimmunity? Indeed, work to date has demonstrated that 10% to 15% of patients with critical COVID-19 pneumonia exhibit autoantibodies against type I interferons, suggesting that preexisting autoimmunity underlies severe disease in some patients. Other studies have identified functional autoantibodies following infection with SARS-CoV-2, such as those that promote thrombosis or antagonize cytokine signaling. These autoantibodies may arise from a predominantly extrafollicular B cell response that is more prone to generating autoantibody-secreting B cells. This Review highlights the current understanding, evolving concepts, and unanswered questions provided by this unique opportunity to determine mechanisms by which a viral infection can be exacerbated by, and even trigger, autoimmunity. The potential role of autoimmunity in post-acute sequelae of COVID-19 is also discussed.


Subject(s)
Autoantibodies/chemistry , Autoimmunity/immunology , COVID-19/immunology , COVID-19/physiopathology , Signal Transduction , Animals , Autoimmune Diseases , B-Lymphocytes/cytology , Cytokines/metabolism , Disease Progression , Female , Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Humans , Inflammation , Interleukin-1/metabolism , Interleukin-6/metabolism , Macrophage Activation , Male , Mice , Phospholipids/metabolism , SARS-CoV-2
5.
J Am Chem Soc ; 143(33): 13205-13211, 2021 08 25.
Article in English | MEDLINE | ID: covidwho-1349637

ABSTRACT

The receptor binding and proteolysis of Spike of SARS-CoV-2 release its S2 subunit to rearrange and catalyze viral-cell fusion. This deploys the fusion peptide for insertion into the cell membranes targeted. We show that this fusion peptide transforms from intrinsic disorder in solution into a wedge-shaped structure inserted in bilayered micelles, according to chemical shifts, 15N NMR relaxation, and NOEs. The globular fold of three helices contrasts the open, extended forms of this region observed in the electron density of compact prefusion states. In the hydrophobic, narrow end of the wedge, helices 1 and 2 contact the fatty acyl chains of phospholipids, according to NOEs and proximity to a nitroxide spin label deep in the membrane mimic. The polar end of the wedge may engage and displace lipid head groups and bind Ca2+ ions for membrane fusion. Polar helix 3 protrudes from the bilayer where it might be accessible to antibodies.


Subject(s)
Micelles , Peptides/metabolism , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , COVID-19/pathology , COVID-19/virology , Humans , Hydrophobic and Hydrophilic Interactions , Peptides/chemistry , Phospholipids/chemistry , Phospholipids/metabolism , Protein Binding , Protein Conformation, alpha-Helical , Protein Subunits/chemistry , Protein Subunits/metabolism , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/metabolism
6.
Science ; 373(6554): 541-547, 2021 07 30.
Article in English | MEDLINE | ID: covidwho-1334531

ABSTRACT

Repurposing drugs as treatments for COVID-19, the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has drawn much attention. Beginning with sigma receptor ligands and expanding to other drugs from screening in the field, we became concerned that phospholipidosis was a shared mechanism underlying the antiviral activity of many repurposed drugs. For all of the 23 cationic amphiphilic drugs we tested, including hydroxychloroquine, azithromycin, amiodarone, and four others already in clinical trials, phospholipidosis was monotonically correlated with antiviral efficacy. Conversely, drugs active against the same targets that did not induce phospholipidosis were not antiviral. Phospholipidosis depends on the physicochemical properties of drugs and does not reflect specific target-based activities-rather, it may be considered a toxic confound in early drug discovery. Early detection of phospholipidosis could eliminate these artifacts, enabling a focus on molecules with therapeutic potential.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Drug Repositioning , Lipidoses/chemically induced , Phospholipids/metabolism , SARS-CoV-2/drug effects , A549 Cells , Animals , Antiviral Agents/chemistry , Antiviral Agents/therapeutic use , Antiviral Agents/toxicity , COVID-19/virology , Cations , Chlorocebus aethiops , Dose-Response Relationship, Drug , Female , Humans , Mice , Microbial Sensitivity Tests , SARS-CoV-2/physiology , Surface-Active Agents/chemistry , Surface-Active Agents/pharmacology , Surface-Active Agents/toxicity , Vero Cells , Virus Replication/drug effects
7.
Biochim Biophys Acta Biomembr ; 1863(11): 183697, 2021 11 01.
Article in English | MEDLINE | ID: covidwho-1316392

ABSTRACT

Fusion peptides (FP) are prominent hydrophobic segments of viral fusion proteins that play critical roles in viral entry. FPs interact with and insert into the host lipid membranes, triggering conformational changes in the viral protein that leads to the viral-cell fusion. Multiple membrane-active domains from the severe acute respiratory syndrome (SARS) coronavirus (CoV) spike protein have been reported to act as the functional fusion peptide such as the peptide sequence located between the S1/S2 and S2' cleavage sites (FP1), the S2'-adjacent fusion peptide domain (FP2), and the internal FP sequence (cIFP). Using a combined biophysical approach, we demonstrated that the α-helical coiled-coil-forming internal cIFP displayed the highest membrane fusion and permeabilizing activities along with membrane ordering effect in phosphatidylcholine (PC)/phosphatidylglycerol (PG) unilamellar vesicles compared to the other two N-proximal fusion peptide counterparts. While the FP1 sequence displayed intermediate membranotropic activities, the well-conserved FP2 peptide was substantially less effective in promoting fusion, leakage, and membrane ordering in PC/PG model membranes. Furthermore, Ca2+ did not enhance the FP2-induced lipid mixing activity in PC/phosphatidylserine/cholesterol lipid membranes, despite its strong erythrocyte membrane perturbation. Nonetheless, we found that the three putative SARS-CoV membrane-active fusion peptide sequences here studied altered the physical properties of model and erythrocyte membranes to different extents. The importance of the distinct membranotropic and biological activities of all SARS-CoV fusion peptide domains and the pronounced effect of the internal fusion peptide sequence to the whole spike-mediated membrane fusion process are discussed.


Subject(s)
Erythrocyte Membrane/metabolism , Phospholipids/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Calcium/chemistry , Calcium/metabolism , Erythrocyte Membrane/chemistry , Humans , Phospholipids/chemistry , Protein Binding , Protein Conformation, alpha-Helical , Protein Domains , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Unilamellar Liposomes/chemistry , Unilamellar Liposomes/metabolism
8.
Cell Metab ; 33(8): 1655-1670.e8, 2021 08 03.
Article in English | MEDLINE | ID: covidwho-1233395

ABSTRACT

How amphipathic phospholipids are shuttled between the membrane bilayer remains an essential but elusive process, particularly at the endoplasmic reticulum (ER). One prominent phospholipid shuttling process concerns the biogenesis of APOB-containing lipoproteins within the ER lumen, which may require bulk trans-bilayer movement of phospholipids from the cytoplasmic leaflet of the ER bilayer. Here, we show that TMEM41B, present in the lipoprotein export machinery, encodes a previously conceptualized ER lipid scramblase mediating trans-bilayer shuttling of bulk phospholipids. Loss of hepatic TMEM41B eliminates plasma lipids, due to complete absence of mature lipoproteins within the ER, but paradoxically also activates lipid production. Mechanistically, scramblase deficiency triggers unique ER morphological changes and unsuppressed activation of SREBPs, which potently promotes lipid synthesis despite stalled secretion. Together, this response induces full-blown nonalcoholic hepatosteatosis in the TMEM41B-deficient mice within weeks. Collectively, our data uncovered a fundamental mechanism safe-guarding ER function and integrity, dysfunction of which disrupts lipid homeostasis.


Subject(s)
Endoplasmic Reticulum , Phospholipids , Animals , Endoplasmic Reticulum/metabolism , Homeostasis , Lipogenesis , Lipoproteins/metabolism , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice , Phospholipids/metabolism
9.
Ultrastruct Pathol ; 44(4-6): 519-523, 2020 Nov 20.
Article in English | MEDLINE | ID: covidwho-960391

ABSTRACT

COVID-19 (from SARS-CoV-2) is the cause of an ongoing pandemic, with an increasing number of cases and significant mortality worldwide. Clinical trials and extensive studies are being conducted on a large scale for a better understanding of the pathophysiology of this disease and its effect on different organs. Several experimental treatment protocols have been introduced, in which hydroxychloroquine (HCQ) was one of the first drugs used. While patients can develop many side effects of HCQ, studies have documented a rare association of long-term HCQ treatment with zebra-like bodies in the ultrastructural examination of kidney biopsies, a finding typically seen in Fabry's disease, as well as in association with chronic HCQ use, among other drugs. We present a similar finding in the postmortem examination of a male in his early seventies with COVID-19 infection, who received five days of HCQ treatment before stopping the medication due to cardiac and renal toxicity.


Subject(s)
Acute Kidney Injury/chemically induced , Antiviral Agents/adverse effects , COVID-19/drug therapy , Hydroxychloroquine/adverse effects , Kidney Tubules/drug effects , Organelles/drug effects , Phospholipids/metabolism , Acute Kidney Injury/metabolism , Acute Kidney Injury/pathology , Aged , Autopsy , Fatal Outcome , Humans , Kidney Tubules/metabolism , Kidney Tubules/ultrastructure , Male , Organelles/metabolism , Organelles/ultrastructure
11.
Cell Stress Chaperones ; 25(6): 979-991, 2020 11.
Article in English | MEDLINE | ID: covidwho-679678

ABSTRACT

Heat shock proteins (HSPs) are ubiquitous polypeptides expressed in all living organisms that participate in several basic cellular processes, including protein folding, from which their denomination as molecular chaperones originated. There are several HSPs, including HSPA5, also known as 78-kDa glucose-regulated protein (GRP78) or binding immunoglobulin protein (BIP) that is an ER resident involved in the folding of polypeptides during their translocation into this compartment prior to the transition to the Golgi network. HSPA5 is detected on the surface of cells or secreted into the extracellular environment. Surface HSPA5 has been proposed to have various roles, such as receptor-mediated signal transduction, a co-receptor for soluble ligands, as well as a participant in tumor survival, proliferation, and resistance. Recently, surface HSPA5 has been reported to be a potential receptor of some viruses, including the novel SARS-CoV-2. In spite of these observations, the association of HSPA5 within the plasma membrane is still unclear. To gain information about this process, we studied the interaction of HSPA5 with liposomes made of different phospholipids. We found that HSPA5 has a high affinity for negatively charged phospholipids, such as palmitoyl-oleoyl phosphoserine (POPS) and cardiolipin (CL). The N-terminal and C-terminal domains of HSPA5 were independently capable of interacting with negatively charged phospholipids, but to a lesser extent than the full-length protein, suggesting that both domains are required for the maximum insertion into membranes. Interestingly, we found that the interaction of HSPA5 with negatively charged liposomes promotes an oligomerization process via intermolecular disulfide bonds in which the N-terminus end of the protein plays a critical role.


Subject(s)
Heat-Shock Proteins/metabolism , Liposomes/metabolism , Phospholipids/chemistry , Amino Acid Sequence , Betacoronavirus/isolation & purification , Betacoronavirus/metabolism , COVID-19 , Calorimetry , Cardiolipins/chemistry , Cardiolipins/metabolism , Coronavirus Infections/pathology , Coronavirus Infections/virology , Endoplasmic Reticulum/metabolism , HSP70 Heat-Shock Proteins/chemistry , HSP70 Heat-Shock Proteins/metabolism , Heat-Shock Proteins/chemistry , Heat-Shock Proteins/genetics , Humans , Liposomes/chemistry , Pandemics , Phosphatidylserines/chemistry , Phosphatidylserines/metabolism , Phospholipids/metabolism , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Protein Domains , Protein Multimerization , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/isolation & purification , SARS-CoV-2 , Sequence Alignment
12.
Biomed Pharmacother ; 130: 110582, 2020 Oct.
Article in English | MEDLINE | ID: covidwho-688980

ABSTRACT

Given the speed of viral infection spread, repurposing of existing drugs has been given the highest priority in combating the ongoing COVID-19 pandemic. Only drugs that are already registered or close to registration, and therefore have passed lengthy safety assessments, have a chance to be tested in clinical trials and reach patients quickly enough to help in the current disease outbreak. Here, we have reviewed available evidence and possible ways forward to identify already existing pharmaceuticals displaying modest broad-spectrum antiviral activity which is likely linked to their high accumulation in cells. Several well studied examples indicate that these drugs accumulate in lysosomes, endosomes and biological membranes in general, and thereby interfere with endosomal pathway and intracellular membrane trafficking crucial for viral infection. With the aim to identify other lysosomotropic drugs with possible inherent antiviral activity, we have applied a set of clear physicochemical, pharmacokinetic and molecular criteria on 530 existing drugs. In addition to publicly available data, we have also used our in silico model for the prediction of accumulation in lysosomes and endosomes. By this approach we have identified 36 compounds with possible antiviral effects, also against coronaviruses. For 14 of them evidence of broad-spectrum antiviral activity has already been reported, adding support to the value of this approach. Presented pros and cons, knowledge gaps and methods to identify lysosomotropic antivirals, can help in the evaluation of many drugs currently in clinical trials considered for repurposing to target COVID-19, as well as open doors to finding more potent and safer alternatives.


Subject(s)
Antiviral Agents/therapeutic use , Betacoronavirus , Coronavirus Infections/drug therapy , Drug Repositioning , Lysosomes/drug effects , Pandemics , Pneumonia, Viral/drug therapy , Anti-Inflammatory Agents/pharmacokinetics , Antiviral Agents/adverse effects , Antiviral Agents/pharmacokinetics , Arrhythmias, Cardiac/chemically induced , Azithromycin/pharmacokinetics , Azithromycin/therapeutic use , COVID-19 , Chemical and Drug Induced Liver Injury/etiology , Chloroquine/pharmacokinetics , Chloroquine/therapeutic use , Computer Simulation , Drug Evaluation, Preclinical , Endosomes/drug effects , Humans , Hydrogen-Ion Concentration , Hydroxychloroquine/pharmacokinetics , Hydroxychloroquine/therapeutic use , Intracellular Membranes/physiology , Lysosomes/chemistry , Membrane Lipids/metabolism , Models, Biological , Phospholipids/metabolism , SARS-CoV-2 , Surface-Active Agents/pharmacokinetics , Virus Internalization
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