ABSTRACT
The 2021 Nobel Prize in Physiology or Medicine was awarded to Ardem Patapoutian and David Julius for their research on receptor channels responsible for the perception of touch and temperature. Somatosensation, an overarching sense that enables us to safely interface with the physical forces around and within us, is the fourth sensory modality to be recognized by the Nobel Committee. The story of the discovery of TRP and PIEZO channels, and subsequent investigations into their myriad roles in the perception of noxious and mild temperature, touch, pain, pressure and body position, is an archetype for how translational research into human and animal health is built on a foundation of excellence in basic science.
Subject(s)
Medicine , Nobel Prize , Physiology , Touch/physiology , Animals , Mechanoreceptors/metabolism , Mice, Knockout , TemperatureABSTRACT
Altered olfactory function is a common symptom of COVID-19, but its etiology is unknown. A key question is whether SARS-CoV-2 (CoV-2) - the causal agent in COVID-19 - affects olfaction directly, by infecting olfactory sensory neurons or their targets in the olfactory bulb, or indirectly, through perturbation of supporting cells. Here we identify cell types in the olfactory epithelium and olfactory bulb that express SARS-CoV-2 cell entry molecules. Bulk sequencing demonstrated that mouse, non-human primate and human olfactory mucosa expresses two key genes involved in CoV-2 entry, ACE2 and TMPRSS2. However, single cell sequencing revealed that ACE2 is expressed in support cells, stem cells, and perivascular cells, rather than in neurons. Immunostaining confirmed these results and revealed pervasive expression of ACE2 protein in dorsally-located olfactory epithelial sustentacular cells and olfactory bulb pericytes in the mouse. These findings suggest that CoV-2 infection of non-neuronal cell types leads to anosmia and related disturbances in odor perception in COVID-19 patients.