Inhibition of acid sphingomyelinase by ambroxol prevents SARS-CoV-2 entry into epithelial cells.

Inhibition of acid sphingomyelinase by ambroxol prevents SARS-CoV-2 entry into epithelial cells.

Barbara Gripp, Katrin Anne Becker, Alexander Carpinteiro, Markus Hoffmann, Stefan Pöhlmann, Nicolas Hoertel, Michael J Edwards, Markus Kamler, Johannes Kornhuber, Erich Gulbins

The acid sphingomyelinase/ceramide system has been shown to be important for cellular infection with at least some viruses, for instance rhinovirus or SARS-CoV-2. Functional inhibition of the acid sphingomyelinase using tricyclic antidepressants prevented infection of epithelial cells, for instance with SARS-CoV-2. The structure of ambroxol, i.e. trans-4-[(2,4-dibromanilin-6-yl)-methyamino]-cyclohexanol, a mucolytic drug applied by inhalation, suggests that the drug might inhibit the acid sphingomyelinase, and thereby infection with SARS-CoV-2. To test this, we used spike protein pseudotyped viral particles (pp-VSV-SARS-CoV-2 spike), a bona fide system for mimicking SARS-CoV-2 entry into cells. Viral uptake and formation of ceramide localization were determined by fluorescence microscopy, activity of the acid sphingomyelinase by consumption of [14C]sphingomyelin and ceramide was quantified by a kinase method. We found that entry of pp-VSV-SARS-CoV-2 spike required activation of acid sphingomyelinase and release of ceramide, events that were all prevented by pretreatment with ambroxol. We also obtained nasal epithelial cells from human volunteers prior to and after inhalation of ambroxol. Inhalation of ambroxol reduced acid sphingomyelinase activity in nasal epithelial cells, and prevented pp-VSV-SARS-CoV-2 spike-induced acid sphingomyelinase activation, ceramide release, and entry of pp-VSV-SARS-CoV-2 spike ex vivo. The addition of purified acid sphingomyelinase or C16 ceramide restored entry of pp-VSV-SARS-CoV-2 spike into ambroxol-treated epithelial cells. We propose that ambroxol might be suitable for clinical studies to prevent COVID-19.

2021

infection, SARS-CoV-2, ambroxol, acid sphingomyelinase, ceramide, human nasal epithelial cells

10.1016/j.jbc.2021.100701

The Journal of biological chemistry