Submitted by Dr R. Inchingolo on Wed, 09/09/2020 - 13:34
Study by the Baker lab identifies novel markers for developing olfactory ensheathing cells and unexpected parallels with oligodendrocytes
Olfactory ensheathing cells (OECs) wrap around and protect the tiny nerve fibres that transmit information about smells from the lining of the nose to the brain. For years, OECs were thought to be unique in arising from the nasal lining. However, Clare Baker’s lab previously showed that OECs originate from an embryonic cell population known as the neural crest, just like the 'Schwann cells' that ensheath all other nerve fibres in the peripheral nervous system (i.e., outside the brain and spinal cord).
To gain a better understanding of how neural crest cells develop into OECs versus Schwann cells, a Wellcome-funded PhD student in Clare Baker's lab, Surangi Perera (now a postdoctoral fellow at the National Institutes of Health in the USA), isolated pieces of embryonic mouse olfactory nerve and trigeminal nerve at different stages and compared their gene expression profiles. The project, which involved collaborations with other groups in the UK, USA and Japan, was recently published in Glia. The study identified 25 novel markers for developing OECs, including genes that distinguish them from developing Schwann cells, and genes that distinguish different subpopulations of OECs in the lining of the nose and close to the brain. The work also uncovered intriguing parallels between the development of OECs and oligodendrocytes, which ensheath nerve fibres in the central nervous system (i.e., inside the brain and spinal cord).
The olfactory nerve is unusual in being regenerated throughout life, as the nasal lining is continually damaged and replaced. OECs remove debris and secrete factors that promote the sprouting of new olfactory nerve fibres. Transplantation studies have shown that OECs can help to promote spinal cord injury repair, as well as repair of other peripheral nerves. In addition to providing new insight into OEC development, therefore, this study may provide a foundation for future translational work to identify and expand patient-specific OECs for the long-term goal of promoting repair of the damaged nervous system.
Reference: Perera SN, Williams RM, Lyne R, Stubbs O, Buehler DP, Sauka-Spengler T, Noda M, Micklem G, Southard-Smith EM, Baker CVH (2020): ‘Insights into olfactory ensheathing cell development from a laser-microdissection and transcriptome-profiling approach.’ Glia, doi: 10.1002/glia.23870