title: 6-Sulphated chondroitins have a positive influence on axonal regeneration.
abstract: Chondroitin sulphate proteoglycans (CSPGs) upregulated in the glial scar inhibit axon regeneration via their sulphated glycosaminoglycans (GAGs). Chondroitin 6-sulphotransferase-1 (C6ST-1) is upregulated after injury leading to an increase in 6-sulphated GAG. In this study, we ask if this increase in 6-sulphated GAG is responsible for the increased inhibition within the glial scar, or whether it represents a partial reversion to the permissive embryonic state dominated by 6-sulphated glycosaminoglycans (GAGs). Using C6ST-1 knockout mice (KO), we studied post-injury changes in chondroitin sulphotransferase (CSST) expression and the effect of chondroitin 6-sulphates on both central and peripheral axon regeneration. After CNS injury, wild-type animals (WT) showed an increase in mRNA for C6ST-1, C6ST-2 and C4ST-1, but KO did not upregulate any CSSTs. After PNS injury, while WT upregulated C6ST-1, KO showed an upregulation of C6ST-2. We examined regeneration of nigrostriatal axons, which demonstrate mild spontaneous axon regeneration in the WT. KO showed many fewer regenerating axons and more axonal retraction than WT. However, in the PNS, repair of the median and ulnar nerves led to similar and normal levels of axon regeneration in both WT and KO. Functional tests on plasticity after the repair also showed no evidence of enhanced plasticity in the KO. Our results suggest that the upregulation of 6-sulphated GAG after injury makes the extracellular matrix more permissive for axon regeneration, and that the balance of different CSs in the microenvironment around the lesion site is an important factor in determining the outcome of nervous system injury.
authors: Department of Clinical Neurosciences, Cambridge Centre for Brain Repair, University of Cambridge, Cambridge, United Kingdom.
authors: Rachel
authors: R
authors: Lin
authors: Thomas W
authors: TW
authors: Rosahl
authors: Paul J
authors: PJ
authors: Whiting
authors: James W
authors: JW
authors: Fawcett
authors: Jessica C F
authors: JC
authors: Kwok
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism*; D001522:Behavior, Animal / Q000502:physiology; D011508:Chondroitin Sulfate Proteoglycans / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D055786:Gene Knockout Techniques; D018737:Hand Strength / Q000502:physiology; D051379:Mice; D009473:Neuronal Plasticity / Q000502:physiology; D017933:Peripheral Nervous System / Q000166:cytology / Q000293:injuries / Q000378:metabolism / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012038:Regeneration; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D013378:Substantia Nigra / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D013431:Sulfates / Q000378:metabolism*; D015238:Sulfotransferases / Q000172:deficiency / Q000235:genetics; D015854:Up-Regulation; D000097811:Carbohydrate Sulfotransferases
chemical_list: D011508:Chondroitin Sulfate Proteoglycans; D012333:RNA, Messenger; D013431:Sulfates; D015238:Sulfotransferases; D000097811:Carbohydrate Sulfotransferases