The extracellular matrix glycoprotein tenascin-C promotes locomotor recovery after spinal cord injury in adult zebrafish

• Published in: Neuroscience Vol. 183; pp. 238 - 250
• Main Authors: Yu, Y.-M, Cristofanilli, M, Valiveti, A, Ma, L, Yoo, M, Morellini, F, Schachner, M
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 02-06-2011; Elsevier
• Subjects: Analysis of Variance; Animals; Biological and medical sciences; Brain Stem - pathology; Cell Count; Choline O-Acetyltransferase - metabolism; Danio rerio; Disease Models, Animal; extracellular matrix; Freshwater; Fundamental and applied biological sciences. Psychology; Humans; Indoles; Lysine - analogs & derivatives; Lysine - metabolism; Membrane Glycoproteins - metabolism; Motor Activity - drug effects; Motor Neurons - metabolism; Nerve Regeneration - drug effects; Neural Pathways - pathology; Neurology; Oligodeoxyribonucleotides, Antisense - therapeutic use; Recovery of Function - drug effects; Recovery of Function - physiology; regeneration; RNA, Messenger - metabolism; spinal cord; Spinal Cord Injuries - drug therapy; Spinal Cord Injuries - metabolism; Spinal Cord Injuries - pathology; Spinal Cord Injuries - physiopathology; Synapses - pathology; Tenascin - genetics; Tenascin - metabolism; tenascin-C; Transcription Factors - metabolism; Up-Regulation - drug effects; Up-Regulation - physiology; Vertebrates: nervous system and sense organs; Zebrafish; Zebrafish Proteins - metabolism; PBS; MO; regeneration; tenascin-C; phosphate-buffered saline; choline acetyltransferase; ChAT; spinal cord; zebrafish; nucleus of median longitudinal fascicle; morpholino; NMLF; extracellular matrix; Tenascin; Regeneration; Vertebrata; Brachydanio rerio; Spinal cord; Pisces; Central nervous system; Glycoprotein; Extracellular matrix; Lesion
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/j.neuroscience.2011.03.043

Abstract Adult zebrafish, by virtue of exhibiting spontaneous recovery after spinal lesion, have evolved into a paradigmatic vertebrate model system to identify novel genes vital for successful regeneration after spinal cord injury. Due to a remarkable level of conservation between zebrafish and human genomes, such genes, once identified, could point to possibilities for addressing the multiple issues on how to deal with functional recovery after spinal cord injury in humans. In the current study, the extracellular matrix glycoprotein tenascin-C was studied in the zebrafish spinal cord injury model to assess the often disparate functions of this multidomain molecule under in vivo conditions. This in vivo study was deemed necessary since in vitro studies had shown discrepant functional effects on neurite outgrowth: tenascin-C inhibits neurite outgrowth when presented as a molecular barrier adjacent to a conducive substrate, but enhances neurite outgrowth when presented as a uniform substrate. Thus, our current study addresses the question as to which of these features prevails in vivo : whether tenascin-C reduces or enhances axonal regrowth after injury in a well accepted vertebrate model of spinal cord injury. We show upregulation of tenascin-C expression in regenerating neurons of the nucleus of median longitudinal fascicle (NMLF) in the brainstem and spinal motoneurons. Inhibition of tenascin-C expression by antisense oligonucleotide (morpholino) resulted in impaired locomotor recovery, reduced regrowth of axons from brainstem neurons and reduced synapse formation by the regrowing brainstem axons on spinal motoneurons, all vital indicators of regeneration. Our results thus point to an advantageous role of tenascin-C in promoting spinal cord regeneration, by promoting axonal regrowth and synapse formation in the spinal cord caudal to the lesion site after injury.