title: A multilevel screening strategy defines a molecular fingerprint of proregenerative olfactory ensheathing cells and identifies SCARB2, a protein that improves regenerative sprouting of injured sensory spinal axons.
abstract: Olfactory ensheathing cells (OECs) have neuro-restorative properties in animal models for spinal cord injury, stroke, and amyotrophic lateral sclerosis. Here we used a multistep screening approach to discover genes specifically contributing to the regeneration-promoting properties of OECs. Microarray screening of the injured olfactory pathway and of cultured OECs identified 102 genes that were subsequently functionally characterized in cocultures of OECs and primary dorsal root ganglion (DRG) neurons. Selective siRNA-mediated knockdown of 16 genes in OECs (ADAMTS1, BM385941, FZD1, GFRA1, LEPRE1, NCAM1, NID2, NRP1, MSLN, RND1, S100A9, SCARB2, SERPINI1, SERPINF1, TGFB2, and VAV1) significantly reduced outgrowth of cocultured DRG neurons, indicating that endogenous expression of these genes in OECs supports neurite extension of DRG neurons. In a gain-of-function screen for 18 genes, six (CX3CL1, FZD1, LEPRE1, S100A9, SCARB2, and SERPINI1) enhanced and one (TIMP2) inhibited neurite growth. The most potent hit in both the loss- and gain-of-function screens was SCARB2, a protein that promotes cholesterol secretion. Transplants of fibroblasts that were genetically modified to overexpress SCARB2 significantly increased the number of regenerating DRG axons that grew toward the center of a spinal cord lesion in rats. We conclude that expression of SCARB2 enhances regenerative sprouting and that SCARB2 contributes to OEC-mediated neuronal repair.
authors.affiliation: Department of Neuroregeneration, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and Sciences, 1105 BA Amsterdam, The Netherlands. kasperroet@gmail.com
authors.forename: Kasper C D
authors.initials: KC
authors.lastname: Roet
authors.forename: Elske H P
authors.initials: EH
authors.lastname: Franssen
authors.forename: Frederik M
authors.initials: FM
authors.lastname: de Bree
authors.forename: Anke H W
authors.initials: AH
authors.lastname: Essing
authors.forename: Sjirk-Jan J
authors.initials: SJ
authors.lastname: Zijlstra
authors.forename: Nitish D
authors.initials: ND
authors.lastname: Fagoe
authors.forename: Hannah M
authors.initials: HM
authors.lastname: Eggink
authors.forename: Ruben
authors.initials: R
authors.lastname: Eggers
authors.forename: August B
authors.initials: AB
authors.lastname: Smit
authors.forename: Ronald E
authors.initials: RE
authors.lastname: van Kesteren
authors.forename: Joost
authors.initials: J
authors.lastname: Verhaagen
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology*; D002478:Cells, Cultured; D005260:Female; D005820:Genetic Testing / Q000379:methods; D057809:HEK293 Cells; D006801:Humans; D051907:Lysosomal Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D000090204:Mesothelin; D054802:Molecular Imprinting / Q000379:methods*; D009416:Nerve Regeneration / Q000502:physiology*; D009830:Olfactory Bulb / Q000502:physiology; D009831:Olfactory Mucosa / Q000166:cytology / Q000502:physiology*; D011247:Pregnancy; D051381:Rats; D011916:Rats, Inbred F344; D017208:Rats, Wistar; D051116:Receptors, Scavenger / Q000096:biosynthesis* / Q000235:genetics; D011984:Sensory Receptor Cells / Q000166:cytology / Q000502:physiology*
chemical_list: D051907:Lysosomal Membrane Proteins; C000715527:MSLN protein, human; C000715529:Msln protein, rat; D051116:Receptors, Scavenger; C074299:SCARB2 protein, human; D000090204:Mesothelin