title: Mmp25β facilitates elongation of sensory neurons during zebrafish development.
abstract: Matrix metalloproteinases (MMPs) are a large and complex family of zinc-dependent endoproteinases widely recognized for their roles in remodeling the extracellular matrix (ECM) during embryonic development, wound healing, and tissue homeostasis. Their misregulation is central to many pathologies, and they have therefore been the focus of biomedical research for decades. These proteases have also recently emerged as mediators of neural development and synaptic plasticity in vertebrates, however, understanding of the mechanistic basis of these roles and the molecular identities of the MMPs involved remains far from complete. We have identified a zebrafish orthologue of mmp25 (a.k.a. leukolysin; MT6-MMP), a membrane-type, furin-activated MMP associated with leukocytes and invasive carcinomas, but which we find is expressed by a subset of the sensory neurons during normal embryonic development. We detect high levels of Mmp25β expression in the trigeminal, craniofacial, and posterior lateral line ganglia in the hindbrain, and in Rohon-Beard cells in the dorsal neural tube during the first 48 h of embryonic development. Knockdown of Mmp25β expression with morpholino oligonucleotides results in larvae that are uncoordinated and insensitive to touch, and which exhibit defects in the development of sensory neural structures. Using in vivo zymography, we observe that Mmp25β morphant embryos show reduced Type IV collagen degradation in regions of the head traversed by elongating axons emanating from the trigeminal ganglion, suggesting that Mmp25β may play a pivotal role in mediating ECM remodeling in the vicinity of these elongating axons.
authors: Department of Biology, University of New Brunswick, New Brunswick, Canada; Department of Biological Sciences, University of Alberta, Alberta, Canada; Department of Pharmacology, University of Alberta, Alberta, Canada.
authors: Bryan D
authors: BD
authors: Crawford
authors: Michelle D
authors: MD
authors: Po
authors: Pillai V
authors: PV
authors: Saranyan
authors: Daniel
authors: D
authors: Forsberg
authors: Richard
authors: R
authors: Schulz
authors: Dave B
authors: DB
authors: Pilgrim
mesh_terms: D000818:Animals; D024141:Collagen Type IV / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000201:enzymology; D047108:Embryonic Development; D005109:Extracellular Matrix / Q000201:enzymology; D005260:Female; D058851:GPI-Linked Proteins / Q000235:genetics / Q000378:metabolism; D017950:Ganglia, Sensory / Q000196:embryology / Q000201:enzymology*; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D055785:Gene Knockdown Techniques; D008297:Male; D053504:Matrix Metalloproteinases, Membrane-Associated / Q000235:genetics / Q000378:metabolism*; D009928:Organ Specificity; D011984:Sensory Receptor Cells / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D024141:Collagen Type IV; D058851:GPI-Linked Proteins; D029961:Zebrafish Proteins; D053504:Matrix Metalloproteinases, Membrane-Associated; C403928:matrix metalloproteinase 25
keywords: ECM remodeling; Leukolysin; MT6-MMP; Mmp25; axon elongation; axon pathfinding; in vivo zymography