Non-neural expression of SARS-CoV-2 entry genes in the olfactory epithelium suggests mechanisms underlying anosmia in COVID-19 patients

David Brann; Tatsuya Tsukahara; Caleb Weinreb; Darren W. Logan; Sandeep Robert Datta

The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.03.25.009084 doi: bioRxiv preprint visualized using AlexaFluor 594 Goat anti-Mouse (Jackson ImmunoResearch, Ca# 115-585-146; RRID:AB_2338881). Sections were counterstained with 4',6-daimidino-2phenylindole (DAPI) and coverslips were mounted using Prolong Gold (Invitrogen) for imaging, using a Leica DMi8 microscope system. Images were processed using Fiji ImageJ software (NIH). Scale bars were applied directly from the Leica acquisition software metadata in ImageJ Tools. Unsharp Mask was applied in ImageJ, and brightness/contrast was adjusted globally. The Tuj1 antibody was validated, as previously described (44) . Anti-ACE2 was raised against a C-terminal synthetic peptide for human ACE2, and was validated by the manufacturer to not cross-react with ACE1 for immunohistochemical labeling of ACE2 in fruit bat nasal tissue as well as in human lower airway. Recombinant human ACE2 abolished labeling with this antibody in a previous study in human tissue, further demonstrating its specificity (69) .