Mechanisms of SARS-CoV-2-associated anosmia

Anosmia, the loss of the sense of smell, is one of the main neurological manifestations of COVID-19. Although the SARS-CoV-2 virus targets the nasal olfactory epithelium, current evidence suggests that neuronal infection is extremely rare in both the olfactory periphery and the brain, prompting the need for mechanistic models that can explain the widespread anosmia in COVID-19 patients. Starting from work identifying the non-neuronal cell types that are infected by SARS-CoV-2 in the olfactory system, we review the effects of infection of these supportive cells in the olfactory epithelium and in the brain and posit the downstream mechanisms through which sense of smell is impaired in COVID-19 patients. We propose that indirect mechanisms contribute to altered olfactory system function in COVID-19-associated anosmia, as opposed to neuronal infection or neuroinvasion into the brain. Such indirect mechanisms include tissue damage, inflammatory responses through immune cell infiltration or systemic circulation of cytokines, and downregulation of odorant receptor genes in olfactory sensory neurons in response to local and systemic signals. We also highlight key unresolved questions raised by recent findings.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:103

Enthalten in:

Physiological reviews - 103(2023), 4 vom: 01. Okt., Seite 2759-2766

Sprache:

Englisch

Beteiligte Personen:

Tsukahara, Tatsuya [VerfasserIn]
Brann, David H [VerfasserIn]
Datta, Sandeep Robert [VerfasserIn]

Links:

Volltext

Themen:

Anosmia
COVID-19
Journal Article
Neuroinflammation
Olfaction
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Review
SARS-CoV-2

Anmerkungen:

Date Completed 03.10.2023

Date Revised 23.03.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1152/physrev.00012.2023

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM358435498