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1.
Mol Cancer Res ; 20(3): 446-455, 2022 03 01.
Article in English | MEDLINE | ID: covidwho-1518187

ABSTRACT

AXL, a receptor tyrosine kinase from the TAM (TYRO3 AXL and MER) subfamily, and its ligand growth arrest-specific 6 (GAS6) are implicated in pathogenesis of a wide array of cancers, acquisition of resistance to diverse anticancer therapies and cellular entry of viruses. The continuous development of AXL inhibitors for treatment of patients with cancer and COVID-19 underscores the need to better characterize the cellular effects of AXL targeting.In the present study, we compared the cellular phenotypes of CRISPR-Cas9-induced depletion of AXL and its pharmacological inhibition with bemcentinib, LDC1267 and gilteritinib. Specifically, we evaluated GAS6-AXL signaling, cell viability and invasion, the endo-lysosomal system and autophagy in glioblastoma cells. We showed that depletion of AXL but not of TYRO3 inhibited GAS6-induced phosphorylation of downstream signaling effectors, AKT and ERK1/2, indicating that AXL is a primary receptor for GAS6. AXL was also specifically required for GAS6-dependent increase in cell viability but was dispensable for viability of cells grown without exogenous addition of GAS6. Furthermore, we revealed that LDC1267 is the most potent and specific inhibitor of AXL activation among the tested compounds. Finally, we found that, in contrast to AXL depletion and its inhibition with LDC1267, cell treatment with bemcentinib and gilteritinib impaired the endo-lysosomal and autophagy systems in an AXL-independent manner. IMPLICATIONS: Altogether, our findings are of high clinical importance as we discovered that two clinically advanced AXL inhibitors, bemcentinib and gilteritinib, may display AXL-independent cellular effects and toxicity.


Subject(s)
Aniline Compounds/therapeutic use , Benzocycloheptenes/therapeutic use , Lysosomes/drug effects , Protein Kinase Inhibitors/therapeutic use , Proto-Oncogene Proteins/antagonists & inhibitors , Pyrazines/therapeutic use , Receptor Protein-Tyrosine Kinases/antagonists & inhibitors , Triazoles/therapeutic use , Aniline Compounds/pharmacology , Autophagy , Benzocycloheptenes/pharmacology , Cell Line, Tumor , Cell Proliferation , Humans , Protein Kinase Inhibitors/pharmacology , Pyrazines/pharmacology , Signal Transduction , Transfection , Triazoles/pharmacology
2.
Exp Mol Med ; 53(5): 956-972, 2021 05.
Article in English | MEDLINE | ID: covidwho-1243283

ABSTRACT

An ongoing pandemic of coronavirus disease 2019 (COVID-19) is now the greatest threat to global public health. Herbal medicines and their derived natural products have drawn much attention in the treatment of COVID-19, but the detailed mechanisms by which natural products inhibit SARS-CoV-2 have not been elucidated. Here, we show that platycodin D (PD), a triterpenoid saponin abundant in Platycodon grandiflorum (PG), a dietary and medicinal herb commonly used in East Asia, effectively blocks the two main SARS-CoV-2 infection routes via lysosome- and transmembrane protease serine 2 (TMPRSS2)-driven entry. Mechanistically, PD prevents host entry of SARS-CoV-2 by redistributing membrane cholesterol to prevent membrane fusion, which can be reinstated by treatment with a PD-encapsulating agent. Furthermore, the inhibitory effects of PD are recapitulated by the pharmacological inhibition or gene silencing of NPC1, which is mutated in patients with Niemann-Pick type C (NPC) displaying disrupted membrane cholesterol distribution. Finally, readily available local foods or herbal medicines containing PG root show similar inhibitory effects against SARS-CoV-2 infection. Our study proposes that PD is a potent natural product for preventing or treating COVID-19 and that briefly disrupting the distribution of membrane cholesterol is a potential novel therapeutic strategy for SARS-CoV-2 infection.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , SARS-CoV-2/drug effects , Saponins/pharmacology , Serine Endopeptidases/metabolism , Triterpenes/pharmacology , Virus Internalization/drug effects , Antiviral Agents/chemistry , COVID-19/metabolism , Cell Line , Humans , Lysosomes/drug effects , Lysosomes/metabolism , Models, Molecular , Platycodon/chemistry , SARS-CoV-2/physiology , Saponins/chemistry , Triterpenes/chemistry
3.
Cells ; 10(5)2021 05 07.
Article in English | MEDLINE | ID: covidwho-1223961

ABSTRACT

The flavonoid naringenin (Nar), present in citrus fruits and tomatoes, has been identified as a blocker of an emerging class of human intracellular channels, namely the two-pore channel (TPC) family, whose role has been established in several diseases. Indeed, Nar was shown to be effective against neoangiogenesis, a process essential for solid tumor progression, by specifically impairing TPC activity. The goal of the present review is to illustrate the rationale that links TPC channels to the mechanism of coronavirus infection, and how their inhibition by Nar could be an efficient pharmacological strategy to fight the current pandemic plague COVID-19.


Subject(s)
COVID-19/drug therapy , Calcium Channel Blockers/pharmacology , Calcium Channels/metabolism , Flavanones/pharmacology , Neoplasms/drug therapy , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Arabidopsis/metabolism , COVID-19/epidemiology , COVID-19/pathology , COVID-19/virology , Calcium Channel Blockers/therapeutic use , Drug Evaluation, Preclinical , Endosomes/drug effects , Endosomes/metabolism , Endosomes/virology , Flavanones/therapeutic use , Humans , Lysosomes/drug effects , Lysosomes/metabolism , Lysosomes/virology , Neoplasms/blood supply , Neoplasms/pathology , Neovascularization, Pathologic/drug therapy , Neovascularization, Pathologic/pathology , Pandemics/prevention & control , SARS-CoV-2/pathogenicity , Vacuoles/metabolism , Virus Internalization/drug effects
4.
Int J Mol Sci ; 22(4)2021 Feb 11.
Article in English | MEDLINE | ID: covidwho-1079663

ABSTRACT

Lysosomotropism is a biological characteristic of small molecules, independently present of their intrinsic pharmacological effects. Lysosomotropic compounds, in general, affect various targets, such as lipid second messengers originating from lysosomal enzymes promoting endothelial stress response in systemic inflammation; inflammatory messengers, such as IL-6; and cathepsin L-dependent viral entry into host cells. This heterogeneous group of drugs and active metabolites comprise various promising candidates with more favorable drug profiles than initially considered (hydroxy) chloroquine in prophylaxis and treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections/Coronavirus disease 2019 (COVID-19) and cytokine release syndrome (CRS) triggered by bacterial or viral infections. In this hypothesis, we discuss the possible relationships among lysosomotropism, enrichment in lysosomes of pulmonary tissue, SARS-CoV-2 infection, and transition to COVID-19. Moreover, we deduce further suitable approved drugs and active metabolites based with a more favorable drug profile on rational eligibility criteria, including readily available over-the-counter (OTC) drugs. Benefits to patients already receiving lysosomotropic drugs for other pre-existing conditions underline their vital clinical relevance in the current SARS-CoV2/COVID-19 pandemic.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Drug Discovery , Lysosomes/drug effects , SARS-CoV-2/drug effects , Small Molecule Libraries/pharmacology , Antiviral Agents/pharmacokinetics , Antiviral Agents/therapeutic use , COVID-19/immunology , COVID-19/metabolism , COVID-19/virology , Chlorpromazine/pharmacokinetics , Chlorpromazine/pharmacology , Chlorpromazine/therapeutic use , Cytokine Release Syndrome/drug therapy , Drug Discovery/methods , Drug Repositioning/methods , Fluvoxamine/pharmacokinetics , Fluvoxamine/pharmacology , Fluvoxamine/therapeutic use , Humans , Hydroxychloroquine/pharmacokinetics , Hydroxychloroquine/pharmacology , Hydroxychloroquine/therapeutic use , Interleukin-1/antagonists & inhibitors , Interleukin-1/immunology , Interleukin-6/antagonists & inhibitors , Interleukin-6/immunology , Lung/drug effects , Lung/immunology , Lung/metabolism , Lung/virology , Lysosomes/immunology , Lysosomes/metabolism , Lysosomes/virology , SARS-CoV-2/immunology , SARS-CoV-2/physiology , Small Molecule Libraries/pharmacokinetics , Small Molecule Libraries/therapeutic use , Virus Replication/drug effects
5.
Toxicol Appl Pharmacol ; 414: 115412, 2021 03 01.
Article in English | MEDLINE | ID: covidwho-1039572

ABSTRACT

COVID-19 is a pandemic with no end in sight. There is only one approved antiviral agent but global stocks are deemed insufficient. Despite in vitro antiviral activity, clinical trials of chloroquine and hydroxychloroquine were disappointing, and they may even impair outcomes. Chloroquine causes zebroid deposits reminiscent of Fabry disease (α-galactosidase A deficiency) and endothelial cells are key targets of COVID-19. We have explored the effect of chloroquine on cultured endothelial cells and its modulation by recombinant α-galactosidase A (agalsidase). Following dose-response studies, 0.5 µg/mL chloroquine was added to cultured human endothelial cells. Neutral red and Lysotracker were used to assess lysosomes. Cytotoxicity was evaluated by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) - MTT assay and cell stress by assessing reactive oxygen species (ROS) and nitric oxide (NO). In endothelial cells, chloroquine induced dose-dependent cytotoxicity at in vitro test concentrations for COVID-19 therapy. At a sublethal concentration, chloroquine significantly induced the accumulation of acid organelles (P < 0.05), increased ROS levels, and decreased NO production (P < 0.05). These adverse effects of chloroquine on endothelial cell biology were decreased by agalsidase-ß (P < 0.05). Chloroquine-induced endothelial cell cytotoxicity and stress is attenuated by agalsidase-ß treatment. This suggests that endothelial cell injury may contribute to the failure of chloroquine as therapy for COVID-19 and may be at least in part related to causing dysfunction of the lysosomal enzyme α-galactosidase A.


Subject(s)
COVID-19/drug therapy , Chloroquine/adverse effects , Endothelial Cells/drug effects , Endothelium, Vascular/drug effects , Lysosomes/drug effects , Oxidative Stress/drug effects , Cell Survival/drug effects , Cells, Cultured , Chloroquine/administration & dosage , Chloroquine/therapeutic use , Endothelial Cells/metabolism , Endothelial Cells/pathology , Endothelium, Vascular/metabolism , Endothelium, Vascular/pathology , Fabry Disease/chemically induced , Humans , Pandemics , Reactive Oxygen Species , SARS-CoV-2
6.
FEBS J ; 287(17): 3664-3671, 2020 09.
Article in English | MEDLINE | ID: covidwho-960850

ABSTRACT

The quest for the effective treatment against coronavirus disease 2019 pneumonia caused by the severe acute respiratory syndrome (SARS)-coronavirus 2(CoV-2) coronavirus is hampered by the lack of knowledge concerning the basic cell biology of the infection. Given that most viruses use endocytosis to enter the host cell, mechanistic investigation of SARS-CoV-2 infection needs to consider the diversity of endocytic pathways available for SARS-CoV-2 entry in the human lung epithelium. Taking advantage of the well-established methodology of membrane trafficking studies, this research direction allows for the rapid characterisation of the key cell biological mechanism(s) responsible for SARS-CoV-2 infection. Furthermore, 11 clinically approved generic drugs are identified as potential candidates for repurposing as blockers of several potential routes for SARS-CoV-2 endocytosis. More broadly, the paradigm of targeting a fundamental aspect of human cell biology to protect against infection may be advantageous in the context of future pandemic outbreaks.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Drug Repositioning , Endocytosis/drug effects , SARS-CoV-2/drug effects , Virus Internalization/drug effects , Alveolar Epithelial Cells/drug effects , Alveolar Epithelial Cells/virology , Amiloride/pharmacology , COVID-19/metabolism , COVID-19/pathology , COVID-19/virology , Caveolae/drug effects , Caveolae/virology , Chlorpromazine/pharmacology , Clathrin-Coated Vesicles/drug effects , Clathrin-Coated Vesicles/virology , Endosomes/drug effects , Endosomes/virology , Humans , Itraconazole/pharmacology , Lung/drug effects , Lung/metabolism , Lung/pathology , Lung/virology , Lysosomes/drug effects , Lysosomes/virology , Nystatin/pharmacology , Pinocytosis/drug effects , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Vinblastine/pharmacology
7.
J Cell Mol Med ; 25(1): 591-595, 2021 01.
Article in English | MEDLINE | ID: covidwho-934013

ABSTRACT

COVID-19 can present with a variety of clinical features, ranging from asymptomatic or mild respiratory symptoms to fulminant acute respiratory distress syndrome (ARDS) depending on the host's immune responses and the extent of the associated pathologies. This implies that several measures need to be taken to limit severely impairing symptoms caused by viral-induced pathology in vital organs. Opioids are most exploited for their analgesic effects but their usage in the palliation of dyspnoea, immunomodulation and lysosomotropism may represent potential usages of opioids in COVID-19. Here, we describe the mechanisms involved in each of these potential usages, highlighting the benefits of using opioids in the treatment of ARDS from SARS-CoV-2 infection.


Subject(s)
Analgesics, Opioid/therapeutic use , COVID-19/drug therapy , COVID-19/etiology , Respiratory Distress Syndrome/drug therapy , Analgesics, Opioid/administration & dosage , COVID-19/complications , Cytokine Release Syndrome/drug therapy , Cytokine Release Syndrome/virology , Dyspnea/drug therapy , Dyspnea/etiology , Humans , Immunomodulation/drug effects , Immunomodulation/physiology , Lysosomes/drug effects , Receptors, Opioid/immunology
9.
Life Sci ; 262: 118541, 2020 Dec 01.
Article in English | MEDLINE | ID: covidwho-816772

ABSTRACT

The possibility is examined that immunomodulatory pharmacotherapy may be clinically useful in managing the pandemic coronavirus disease 2019 (COVID-19), known to result from infection by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a positive-sense single-stranded RNA virus. The dominant route of cell entry of the coronavirus is via phagocytosis, with ensconcement in endosomes thereafter proceeding via the endosomal pathway, involving transfer from early (EEs) to late endosomes (LEs) and ultimately into lysosomes via endolysosomal fusion. EE to LE transportation is a rate-limiting step for coronaviruses. Hence inhibition or dysregulation of endosomal trafficking could potentially inhibit SARS-CoV-2 replication. Furthermore, the acidic luminal pH of the endolysosomal system is critical for the activity of numerous pH-sensitive hydrolytic enzymes. Golgi sub-compartments and Golgi-derived secretory vesicles also depend on being mildly acidic for optimal function and structure. Activation of endosomal toll-like receptors by viral RNA can upregulate inflammatory mediators and contribute to a systemic inflammatory cytokine storm, associated with a worsened clinical outcome in COVID-19. Such endosomal toll-like receptors could be inhibited by the use of pharmacological agents which increase endosomal pH, thereby reducing the activity of acid-dependent endosomal proteases required for their activity and/or assembly, leading to suppression of antigen-presenting cell activity, decreased autoantibody secretion, decreased nuclear factor-kappa B activity and decreased pro-inflammatory cytokine production. It is also noteworthy that SARS-CoV-2 inhibits autophagy, predisposing infected cells to apoptosis. It is therefore also suggested that further pharmacological inhibition of autophagy might encourage the apoptotic clearance of SARS-CoV-2-infected cells.


Subject(s)
Antiviral Agents/pharmacology , Autophagy/drug effects , COVID-19/drug therapy , COVID-19/virology , Endosomes/drug effects , Lysosomes/drug effects , SARS-CoV-2/drug effects , Azithromycin/adverse effects , Azithromycin/pharmacology , Azithromycin/therapeutic use , Humans , Hydroxychloroquine/adverse effects , Hydroxychloroquine/pharmacology , Hydroxychloroquine/therapeutic use , Pandemics
10.
Int J Mol Sci ; 21(12)2020 Jun 20.
Article in English | MEDLINE | ID: covidwho-742794

ABSTRACT

Resistance to chemotherapeutics and targeted drugs is one of the main problems in successful cancer therapy. Various mechanisms have been identified to contribute to drug resistance. One of those mechanisms is lysosome-mediated drug resistance. Lysosomes have been shown to trap certain hydrophobic weak base chemotherapeutics, as well as some tyrosine kinase inhibitors, thereby being sequestered away from their intracellular target site. Lysosomal sequestration is in most cases followed by the release of their content from the cell by exocytosis. Lysosomal accumulation of anticancer drugs is caused mainly by ion-trapping, but active transport of certain drugs into lysosomes was also described. Lysosomal low pH, which is necessary for ion-trapping is achieved by the activity of the V-ATPase. This sequestration can be successfully inhibited by lysosomotropic agents and V-ATPase inhibitors in experimental conditions. Clinical trials have been performed only with lysosomotropic drug chloroquine and their results were less successful. The aim of this review is to give an overview of lysosomal sequestration and expression of acidifying enzymes as yet not well known mechanism of cancer cell chemoresistance and about possibilities how to overcome this form of resistance.


Subject(s)
Drug Resistance, Neoplasm , Lysosomes/enzymology , Neoplasms/enzymology , Vacuolar Proton-Translocating ATPases/antagonists & inhibitors , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Drug Resistance, Neoplasm/drug effects , Exocytosis , Gene Expression Regulation, Neoplastic/drug effects , Humans , Hydrogen-Ion Concentration , Lysosomes/drug effects , Neoplasms/drug therapy
11.
Cells ; 9(9)2020 08 25.
Article in English | MEDLINE | ID: covidwho-730305

ABSTRACT

An outbreak of the novel coronavirus (CoV) SARS-CoV-2, the causative agent of COVID-19 respiratory disease, infected millions of people since the end of 2019, led to high-level morbidity and mortality and caused worldwide social and economic disruption. There are currently no antiviral drugs available with proven efficacy or vaccines for its prevention. An understanding of the underlying cellular mechanisms involved in virus replication is essential for repurposing the existing drugs and/or the discovery of new ones. Endocytosis is the important mechanism of entry of CoVs into host cells. Endosomal maturation followed by the fusion with lysosomes are crucial events in endocytosis. Late endosomes and lysosomes are characterized by their acidic pH, which is generated by a proton transporter V-ATPase and required for virus entry via endocytic pathway. The cytoplasmic cAMP pool produced by soluble adenylyl cyclase (sAC) promotes V-ATPase recruitment to endosomes/lysosomes and thus their acidification. In this review, we discuss targeting the sAC-specific cAMP pool as a potential strategy to impair the endocytic entry of the SARS-CoV-2 into the host cell. Furthermore, we consider the potential impact of sAC inhibition on CoV-induced disease via modulation of autophagy and apoptosis.


Subject(s)
Adenylyl Cyclase Inhibitors/therapeutic use , Adenylyl Cyclases/metabolism , Betacoronavirus/physiology , Coronavirus Infections/drug therapy , Coronavirus Infections/prevention & control , Cyclic AMP/antagonists & inhibitors , Pandemics/prevention & control , Pneumonia, Viral/drug therapy , Pneumonia, Viral/prevention & control , Antiviral Agents/pharmacology , Apoptosis/drug effects , Autophagy/drug effects , COVID-19 , Coronavirus Infections/metabolism , Coronavirus Infections/virology , Cyclic AMP/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism , Endocytosis/drug effects , Endosomes/drug effects , Endosomes/metabolism , Humans , Lysosomes/drug effects , Lysosomes/metabolism , Pneumonia, Viral/metabolism , Pneumonia, Viral/virology , SARS-CoV-2 , Virus Internalization/drug effects , Virus Replication/drug effects
12.
Cell Death Dis ; 11(8): 656, 2020 08 19.
Article in English | MEDLINE | ID: covidwho-725491

ABSTRACT

The current epidemic of coronavirus disease-19 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) calls for the development of inhibitors of viral replication. Here, we performed a bioinformatic analysis of published and purported SARS-CoV-2 antivirals including imatinib mesylate that we found to suppress SARS-CoV-2 replication on Vero E6 cells and that, according to the published literature on other coronaviruses is likely to act on-target, as a tyrosine kinase inhibitor. We identified a cluster of SARS-CoV-2 antivirals with characteristics of lysosomotropic agents, meaning that they are lipophilic weak bases capable of penetrating into cells. These agents include cepharentine, chloroquine, chlorpromazine, clemastine, cloperastine, emetine, hydroxychloroquine, haloperidol, ML240, PB28, ponatinib, siramesine, and zotatifin (eFT226) all of which are likely to inhibit SARS-CoV-2 replication by non-specific (off-target) effects, meaning that they probably do not act on their 'official' pharmacological targets, but rather interfere with viral replication through non-specific effects on acidophilic organelles including autophagosomes, endosomes, and lysosomes. Imatinib mesylate did not fall into this cluster. In conclusion, we propose a tentative classification of SARS-CoV-2 antivirals into specific (on-target) versus non-specific (off-target) agents based on their physicochemical characteristics.


Subject(s)
Betacoronavirus/physiology , Coronavirus Infections/metabolism , Drug Evaluation, Preclinical/methods , Pneumonia, Viral/metabolism , Virus Replication/drug effects , Animals , Antiviral Agents/pharmacology , COVID-19 , Cell Death/drug effects , Chlorocebus aethiops , Coronavirus Infections/virology , Hydroxychloroquine/pharmacology , Imatinib Mesylate/pharmacology , Lysosomes/drug effects , Pandemics , Pneumonia, Viral/virology , Protein Kinase Inhibitors/pharmacology , RNA, Viral/drug effects , SARS-CoV-2 , Vero Cells , Viral Load/drug effects
13.
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
14.
Cell Signal ; 73: 109706, 2020 09.
Article in English | MEDLINE | ID: covidwho-625663

ABSTRACT

Chloroquine (CQ) and its analogue hydroxychloroquine (HCQ) have been thrust into our everyday vernacular because some believe, based on very limited basic and clinical data, that they might be helpful in preventing and/or lessening the severity of the pandemic coronavirus disease 2019 (COVID-19). However, lacking is a temperance in enthusiasm for their possible use as well as sufficient perspective on their effects and side-effects. CQ and HCQ have well-known properties of being diprotic weak bases that preferentially accumulate in acidic organelles (endolysosomes and Golgi apparatus) and neutralize luminal pH of acidic organelles. These primary actions of CQ and HCQ are responsible for their anti-malarial effects; malaria parasites rely on acidic digestive vacuoles for survival. Similarly, de-acidification of endolysosomes and Golgi by CQ and HCQ may block severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) integration into host cells because SARS-CoV-2 may require an acidic environment for its entry and for its ability to bud and infect bystander cells. Further, de-acidification of endolysosomes and Golgi may underly the immunosuppressive effects of these two drugs. However, modern cell biology studies have shown clearly that de-acidification results in profound changes in the structure, function and cellular positioning of endolysosomes and Golgi, in signaling between these organelles and other subcellular organelles, and in fundamental cellular functions. Thus, studying the possible therapeutic effects of CQ and HCQ against COVID-19 must occur concurrent with studies of the extent to which these drugs affect organellar and cell biology. When comprehensively examined, a better understanding of the Janus sword actions of these and other drugs might yield better decisions and better outcomes.


Subject(s)
Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Chloroquine/pharmacology , Endosomes/drug effects , Golgi Apparatus/drug effects , Hydroxychloroquine/pharmacology , Antimalarials/pharmacology , Antimalarials/therapeutic use , Antiviral Agents/therapeutic use , Betacoronavirus/enzymology , Betacoronavirus/metabolism , Betacoronavirus/pathogenicity , COVID-19 , Chloroquine/therapeutic use , Coronavirus Infections/drug therapy , Cytokines/metabolism , Endocytosis/drug effects , Endosomes/metabolism , Golgi Apparatus/metabolism , Humans , Hydrogen-Ion Concentration , Hydroxychloroquine/therapeutic use , Lysosomes/drug effects , Lysosomes/metabolism , Malaria/drug therapy , Pandemics/prevention & control , Pneumonia, Viral/drug therapy , SARS-CoV-2
15.
Cells ; 9(6)2020 06 13.
Article in English | MEDLINE | ID: covidwho-603067

ABSTRACT

There is no vaccine or specific antiviral treatment for COVID-19, which is causing a global pandemic. One current focus is drug repurposing research, but those drugs have limited therapeutic efficacies and known adverse effects. The pathology of COVID-19 is essentially unknown. Without this understanding, it is challenging to discover a successful treatment to be approved for clinical use. This paper addresses several key biological processes of reactive oxygen, halogen and nitrogen species (ROS, RHS and RNS) that play crucial physiological roles in organisms from plants to humans. These include why superoxide dismutases, the enzymes to catalyze the formation of H2O2, are required for protecting ROS-induced injury in cell metabolism, why the amount of ROS/RNS produced by ionizing radiation at clinically relevant doses is ~1000 fold lower than the endogenous ROS/RNS level routinely produced in the cell and why a low level of endogenous RHS plays a crucial role in phagocytosis for immune defense. Herein we propose a plausible amplification mechanism in immune defense: ozone-depleting-like halogen cyclic reactions enhancing RHS effects are responsible for all the mentioned physiological functions, which are activated by H2O2 and deactivated by NO signaling molecule. Our results show that the reaction cycles can be repeated thousands of times and amplify the RHS pathogen-killing (defense) effects by 100,000 fold in phagocytosis, resembling the cyclic ozone-depleting reactions in the stratosphere. It is unraveled that H2O2 is a required protective signaling molecule (angel) in the defense system for human health and its dysfunction can cause many diseases or conditions such as autoimmune disorders, aging and cancer. We also identify a class of potent drugs for effective treatment of invading pathogens such as HIV and SARS-CoV-2 (COVID-19), cancer and other diseases, and provide a molecular mechanism of action of the drugs or candidates.


Subject(s)
Antiviral Agents/chemistry , Coronavirus Infections/drug therapy , Coronavirus Infections/immunology , Heterocyclic Compounds/therapeutic use , Hydrocarbons, Halogenated/therapeutic use , Pneumonia, Viral/drug therapy , Pneumonia, Viral/immunology , Animals , Antiviral Agents/therapeutic use , COVID-19 , Coronavirus Infections/metabolism , Humans , Hydrogen Peroxide/metabolism , Lysosomes/drug effects , Pandemics , Phagocytosis , Pneumonia, Viral/metabolism , Respiratory Burst/drug effects , Signal Transduction
16.
Autophagy ; 16(12): 2260-2266, 2020 12.
Article in English | MEDLINE | ID: covidwho-593676

ABSTRACT

During the last week of December 2019, Wuhan (China) was confronted with the first case of respiratory tract disease 2019 (coronavirus disease 2019, COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Due to the rapid outbreak of the transmission (~3.64 million positive cases and high mortality as of 5 May 2020), the world is looking for immediate and better therapeutic options. Still, much information is not known, including origin of the disease, complete genomic characterization, mechanism of transmission dynamics, extent of spread, possible genetic predisposition, clinical and biological diagnosis, complete details of disease-induced pathogenicity, and possible therapeutic options. Although several known drugs are already under clinical evaluation with many in repositioning strategies, much attention has been paid to the aminoquinoline derivates, chloroquine (CQ) and hydroxychloroquine (HCQ). These molecules are known regulators of endosomes/lysosomes, which are subcellular organelles central to autophagy processes. By elevating the pH of acidic endosomes/lysosomes, CQ/HCQ inhibit the autophagic process. In this short perspective, we discuss the roles of CQ/HCQ in the treatment of COVID-19 patients and propose new ways of possible treatment for SARS-CoV-2 infection based on the molecules that selectivity target autophagy.Abbreviation: ACE2: angiotensin I converting enzyme 2; CoV: coronavirus; CQ: chloroquine; ER: endoplasmic reticulum; HCQ: hydroxychloroquine; MERS-CoV: Middle East respiratory syndrome coronavirus; SARS-CoV: severe acute respiratory syndrome coronavirus; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2.


Subject(s)
Autophagy/physiology , COVID-19/immunology , Chloroquine/pharmacology , SARS-CoV-2/drug effects , SARS-CoV-2/immunology , Autophagy/drug effects , COVID-19/drug therapy , COVID-19/pathology , COVID-19/virology , Chloroquine/therapeutic use , Endosomes/drug effects , Endosomes/metabolism , Humans , Hydrogen-Ion Concentration/drug effects , Hydroxychloroquine/pharmacology , Hydroxychloroquine/therapeutic use , Immunity, Innate/physiology , Lysosomes/drug effects , Lysosomes/metabolism , Molecular Targeted Therapy/methods , Molecular Targeted Therapy/trends , SARS-CoV-2/pathogenicity , Severity of Illness Index
17.
Int J Antimicrob Agents ; 56(2): 106044, 2020 Aug.
Article in English | MEDLINE | ID: covidwho-548972

ABSTRACT

While the coronavirus disease 2019 (COVID-19) pandemic advances, the scientific community continues to struggle in the search for treatments. Several improvements have been made, including discovery of the clinical efficacy of chloroquine (CQ) in patients with COVID-19, but effective treatment protocols remain elusive. In the search for novel treatment options, many scientists have used the in-silico approach to identify compounds that could interfere with the key molecules involved in entrance, replication or dissemination of severe acute respiratory syndrome coronavirus-2. However, most of the identified molecules are not available as pharmacological agents at present, and assessment of their safety and efficacy could take many months. This review took a different approach based on the proposed pharmacodynamic model of CQ in COVID-19. The main mechanism of action responsible for the favourable outcome of patients with COVID-19 treated with CQ seems to be related to a pH-modulation-mediated effect on endolysosomal trafficking, a characteristic of chemical compounds often called 'lysosomotropic agents' because of the physico-chemical properties that enable them to diffuse passively through the endosomal membrane and undergo protonation-based trapping in the lumen of the acidic vesicles. This review discusses lysosomotropic and lysosome targeting drugs that are already in clinical use and are characterized by good safety profiles, low cost and wide availability. Some of these drugs -particularly azithromycin and other macrolides, indomethacin and some other non-steroidal anti-inflammatory drugs, proton pump inhibitors and fluoxetine - could provide additional therapeutic benefits in addition to the potential antiviral effect that is still to be confirmed by well-controlled clinical trials. As some of these drugs have probably been used empirically in the treatment of COVID-19, it is hoped that colleagues worldwide will publish patient data to enable evaluation of the potential efficacy of these agents in the clinical context, and rapid implementation in therapeutic protocols if they are shown to have a beneficial effect on clinical outcome.


Subject(s)
Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Lysosomes/drug effects , Pneumonia, Viral/drug therapy , Antiviral Agents/pharmacology , Betacoronavirus/physiology , COVID-19 , Coronavirus Infections/virology , Drug Repositioning , Humans , Pandemics , Pneumonia, Viral/virology , SARS-CoV-2 , Virus Replication/drug effects
18.
J Lipid Res ; 61(7): 972-982, 2020 07.
Article in English | MEDLINE | ID: covidwho-382050

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus (SARS-CoV)-2 has resulted in the death of more than 328,000 persons worldwide in the first 5 months of 2020. Herculean efforts to rapidly design and produce vaccines and other antiviral interventions are ongoing. However, newly evolving viral mutations, the prospect of only temporary immunity, and a long path to regulatory approval pose significant challenges and call for a common, readily available, and inexpensive treatment. Strategic drug repurposing combined with rapid testing of established molecular targets could provide a pause in disease progression. SARS-CoV-2 shares extensive structural and functional conservation with SARS-CoV-1, including engagement of the same host cell receptor (angiotensin-converting enzyme 2) localized in cholesterol-rich microdomains. These lipid-enveloped viruses encounter the endosomal/lysosomal host compartment in a critical step of infection and maturation. Niemann-Pick type C (NP-C) disease is a rare monogenic neurodegenerative disease caused by deficient efflux of lipids from the late endosome/lysosome (LE/L). The NP-C disease-causing gene (NPC1) has been strongly associated with viral infection, both as a filovirus receptor (e.g., Ebola) and through LE/L lipid trafficking. This suggests that NPC1 inhibitors or NP-C disease mimetics could serve as anti-SARS-CoV-2 agents. Fortunately, there are such clinically approved molecules that elicit antiviral activity in preclinical studies, without causing NP-C disease. Inhibition of NPC1 may impair viral SARS-CoV-2 infectivity via several lipid-dependent mechanisms, which disturb the microenvironment optimum for viral infectivity. We suggest that known mechanistic information on NPC1 could be utilized to identify existing and future drugs to treat COVID-19.


Subject(s)
Anticholesteremic Agents/therapeutic use , Antiviral Agents/therapeutic use , Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Intracellular Signaling Peptides and Proteins/genetics , Niemann-Pick Disease, Type C/drug therapy , Pandemics , Pneumonia, Viral/drug therapy , Androstenes/therapeutic use , Angiotensin-Converting Enzyme 2 , Betacoronavirus/metabolism , Betacoronavirus/pathogenicity , COVID-19 , Cholesterol/metabolism , Coronavirus Infections/diagnosis , Coronavirus Infections/epidemiology , Drug Repositioning/methods , Humans , Hydroxychloroquine/therapeutic use , Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Intracellular Signaling Peptides and Proteins/metabolism , Lysosomes/drug effects , Lysosomes/metabolism , Lysosomes/virology , Niemann-Pick C1 Protein , Niemann-Pick Disease, Type C/genetics , Niemann-Pick Disease, Type C/metabolism , Niemann-Pick Disease, Type C/pathology , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/diagnosis , Pneumonia, Viral/epidemiology , Protein Binding , Receptors, Virus/antagonists & inhibitors , Receptors, Virus/genetics , Receptors, Virus/metabolism , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism
19.
Int J Antimicrob Agents ; 55(6): 106007, 2020 Jun.
Article in English | MEDLINE | ID: covidwho-197691

ABSTRACT

A recent report identified significant reductions or disappearance of viral load in COVID-19 patients given a combination of hydroxychloroquine and azithromycin. The present communication discusses some common pharmacokinetic properties of these two drugs that may be linked to a potential underlying mechanism of action for these antiviral effects. The physicochemical properties of both hydroxychloroquine and azithromycin are consistent with particularly high affinity for the intracellular lysosomal space, which has been implicated as a target site for antiviral activity. The properties of both drugs predict dramatic accumulation in lysosomes, with calculated lysosomal drug concentrations that exceed cytosolic and extracellular concentrations by more than 50 000-fold. These predictions are consistent with previously reported experimentally measured cellular and extracellular concentrations of azithromycin. This is also reflected in the very large volumes of distribution of these drugs, which are among the highest of all drugs currently in use. The combination of hydroxychloroquine and azithromycin produces very high local concentrations in lysosomes. The clinical significance of this observation is unclear; however, the magnitude of this mechanism of drug accumulation via ion-trapping in lysosomes could be an important factor for the pharmacodynamic effects of this drug combination.


Subject(s)
Azithromycin/pharmacology , Azithromycin/pharmacokinetics , Hydroxychloroquine/pharmacology , Hydroxychloroquine/pharmacokinetics , Lysosomes/drug effects , Antiviral Agents/pharmacokinetics , Antiviral Agents/pharmacology , Betacoronavirus/drug effects , COVID-19 , Coronavirus Infections/drug therapy , Humans , Pandemics , Pneumonia, Viral/drug therapy , SARS-CoV-2 , Viral Load/drug effects
20.
Cell Calcium ; 88: 102212, 2020 06.
Article in English | MEDLINE | ID: covidwho-186635
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