Extracellular matrix protein anosmin-1 modulates olfactory ensheathing cell maturation in chick olfactory bulb development

Hu, Youli, Butts, Thomas, Poopalasundaram, Subathra, Graham, Anthony and Bouloux, Pierre-Marc (2019) Extracellular matrix protein anosmin-1 modulates olfactory ensheathing cell maturation in chick olfactory bulb development. EUROPEAN JOURNAL OF NEUROSCIENCE, 50 (9). pp. 3472-3486.

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Official URL: http://dx.doi.org/10.1111/ejn.14483

Abstract

Olfactory ensheathing cells (OECs) are a specialized class of glia, wrapping around olfactory sensory axons that target the olfactory bulb (OB) and cross the peripheral nervous system/central nervous system boundary during development and continue to do so post-natally. OEC subpopulations perform distinct subtype-specific functions dependent on their maturity status. Disrupted OEC development is thought to be associated with abnormal OB morphogenesis, leading to anosmia, a defining characteristic of Kallmann syndrome. Hence, anosmin-1 encoded by Kallmann syndrome gene (KAL-1) might modulate OEC differentiation/maturation in the OB. We performed in ovo electroporation of shRNA in the olfactory placode to knock-down kal in chick embryos, resulting in abnormal OB morphogenesis and loss of olfactory sensory axonal innervation into OB. BLBP-expressing OECs appeared to form a thinner and poorly organized outmost OB layer where SOX10 expressing OECs were completely absent with emergence of GFAP-expressing OECs. Furthermore, in embryonic day 10 chick OB explant cultures, GFAP expression in OECs accumulating along the OB nerve layers was dramatically reduced by recombinant anosmin-1. We then purified immature OECs from embryonic day 10 chick OB. These cells express GFAP after 7 days in vitro, exhibiting a multipolar morphology. Overexpression of chick anosmin, exogenous anosmin-1 or FGF2 could inhibit GFAP expression with cells presenting elongated morphology, which was blocked by the FGF receptor inhibitor Su5402. These data demonstrate that anosmin-1 functions via FGF signalling in regulating OEC maturation, thereby providing a permissive glial environment for axonal innervation into the OB during development.

Item Type:	Article
Uncontrolled Keywords:	astrocyte, embryo, fibroblast growth factor receptor, Kallmann syndrome
Depositing User:	Symplectic Admin
Date Deposited:	20 Jun 2019 08:02
Last Modified:	19 Jan 2023 00:39
DOI:	10.1111/ejn.14483
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3046630