Amiodarone Alters Late Endosomes and Inhibits SARS Coronavirus Infection at a Post-Endosomal Level

Abstract

Amiodarone interferes with the endocytic pathway, inhibits proteolysis, and causes the formation of vacuoles, but uptake and intracellular distribution of the drug, origin of vacuoles, and functional consequences of amiodarone accumulation remain unclear. Our objective was to study amiodarone uptake, clarify the origin of vacuoles, and investigate the effect of amiodarone on the life cycle of the coronavirus responsible for the Severe Acute Respiratory Syndrome (SARS), which, to enter cells, relies on the proteolytic cleavage of a viral spike protein by the endosomal proteinase cathepsin L. Using alveolar macrophages, we studied uptake of (125)I-amiodarone and (125)I-B2, an analog lacking the lateral group diethylamino-beta-ethoxy, and analyzed the effects of amiodarone on the distribution of endosomal markers and on the uptake of an acidotropic dye. Furthermore, using Vero cells, we tested the impact of amiodarone on the in vitro spreading of the SARS coronavirus. We found that (1) amiodarone associates with different cell membranes and accumulates in acidic organelles; (2) the diethylamino-beta-ethoxy group is an important determinant of uptake; (3) vacuoles forming upon exposure to amiodarone are enlarged late endosomes; (4) amiodarone inhibits the spreading in vitro of SARS coronavirus; and (5) trypsin cleavage of the viral spike protein before infection, which permits virus entry through the plasma membrane, does not impair amiodarone antiviral activity. We conclude that amiodarone alters late compartments of the endocytic pathway and inhibits SARS coronavirus infection by acting after the transit of the virus through endosomes.

Single-Cell Analysis: Visualizing Pharmaceutical and Metabolite Uptake in Cells with Label-Free 3D Mass Spectrometry Imaging

“…This observation is supported by conventional radio-labeling studies preformed by Stadler and co-workers. 30 Through the systematic inhibition of the endocytotic pathways (i.e.…”

“…30 Unfortunately, since the quantity of the radiation released by radio-isotope is independent of the structure of the tracer molecule, it is impossible to differentiate the drug molecule from its metabolites.…”

The spike protein of SARS-CoV — a target for vaccine and therapeutic development

“…For example, amiodarone blocks the in vitro spread of SARS-CoV by inhibiting virus infection at a post-endosomal level107. Yi et al 108 identified two small molecules, tetra-o-galloyl-beta-d-glucose (TGG) and luteolin, which have inhibitory activity, that blocked SARS-CoV or SARS pseudovirus entry into Vero E6 cells.…”

Anti-SARS coronavirus agents: a patent review (2008 – present)

“…A patent [76] as detailed in paper [77] owns the idea for treatment and prophylaxis of viral diseases using diiodobenzoylbenzofuran derivatives like amiodarone (11 of Figure 1), dronedarone, mono-desethyl-amiodarone, and di-desethyl-amiodarone. These compounds are claimed to be effective when administered in forms of suitable pharmaceutical preparations and administered either as tablets, capsules (soft, hard, oily, operculate), dragees or powders (as suspension or emulsion).…”