UDP-glucuronosyltransferases (UGTs) in neuro-olfactory tissues: expression, regulation, and function

Abstract

This work aims to review uridine diphosphate (UDP)-glucuronosyltransferase (UGT) expression and activities along different neuronal structures involved in the common physiological process of olfaction: olfactory epithelium, olfactory bulb, and olfactory cortex. For the first time, using high-throughput in situ hybridization data generated by the Allen Brain Atlas (ABA), we present quantitative analysis of spatial distribution of UGT genes in the mouse brain. The olfactory area is a central nervous system site with the highest expression of UGTs, including UGT isoforms not previously identified in the brain. Since there is evidence of the transfer of xenobiotics to the brain through the nasal pathway, circumventing the blood-brain barrier, olfactory UGTs doubtlessly share the common function of detoxification, but they are also involved in the metabolism and turnover of exogenous or endogenous compounds critical for physiological olfactory processing in these tissues. The function of olfactory UGTs will be discussed with a special focus on their participation in the perireceptor events involved in the modulation of olfactory perception.

Keywords::

• xenobiotic metabolizing enzymes
• olfactory epithelium
• olfactory bulb
• olfactory cortex
• brain distribution
• blood-brain barrier
• perireceptor events

Acknowledgements

EJH wishes to thank Dr Anna Radominska-Pandya for stimulating discussions JMH gratefully thank Dr Anna Radominska-Pandya for her confidence and expert advice. Funding: This work was supported by the Conseil Régional de Bourgogne, the Université de Bourgogne and the Institut National de la Recherche Agronomique.

Declaration of interest: The authors have declared that there are no competing interests.