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Conference Paper: The Mechanisms of Chondroitin Sulphate Lyases Treatment in Promotion of Axonal Growth

TitleThe Mechanisms of Chondroitin Sulphate Lyases Treatment in Promotion of Axonal Growth
Authors
Issue Date2012
Citation
Hong Kong-Taiwan Physiology Symposium 2012 and Joint Scientific Meeting of Hong Kong Society of Neurosciences (HKSN) & The Biophysical Society of Hong Kong (BPHK), The Chinese University of Hong Kong, Hong Kong, China, 14-15 June 2012, p. 72-73, abstract no. P57 How to Cite?
AbstractIn Injured nerves, chondroitin sulphate (CS) is upregulated forming barriers with astrocytes/fibroblasts and other extracellular matrix molecules, and thereby hampering nerve regeneration. Cleavage of CS using chondroitin sulphate lyases (Proteus vulgaris) promises axon regrowth through the barrier but the enzymatic efficacy remains to be improved. Two subtypes, endolyase and exolyase, have been found coexisting in the original host but only the former has been exploited for treatment of injured nerve tracts. We hypothesise that the two subtypes are necessary for enzymatic efficacy on CSs. We therefore prepared recombinant enzymes of both subtypes. Enzyme kinetics study revealed feedback inhibition by limit digestion products: that of the endolyase by tetrasaccharides and that of the exolyase by the disaccharides. When the two subtypes were used in combination, the digestion efficiency increased. We then used TGF beta-1 to induce CS production by astrocytes in culture, mimicking reactive glia in injured nerves. In co-cultures of such astrocytes with cortical neurons, treatment with combinations of the two subtypes resulted in increased neurite lengths as compared to co-cultures treated with one of the subtypes. The limit digestion products of CS were further tested for their effects on neurite extension on astrocytes that had been treated with TGF beta-1. The CS disaccharides, both 4- and 6-sulphated but not the tetrasaccharides, promoted neurite extension significantly. Taken together, the combinatorial use of the ChABC subtypes not only improved efficacy of enzyme activity on the axon-restrictive CS moiety, but also increased the yield of CS disaccharides which contributed to axonal growth.
DescriptionPoster presentation
Persistent Identifierhttp://hdl.handle.net/10722/153015

 

DC FieldValueLanguage
dc.contributor.authorTam, KWen_US
dc.contributor.authorChan, YSen_US
dc.contributor.authorShum, DKYen_US
dc.date.accessioned2012-07-16T09:54:55Z-
dc.date.available2012-07-16T09:54:55Z-
dc.date.issued2012en_US
dc.identifier.citationHong Kong-Taiwan Physiology Symposium 2012 and Joint Scientific Meeting of Hong Kong Society of Neurosciences (HKSN) & The Biophysical Society of Hong Kong (BPHK), The Chinese University of Hong Kong, Hong Kong, China, 14-15 June 2012, p. 72-73, abstract no. P57en_US
dc.identifier.urihttp://hdl.handle.net/10722/153015-
dc.descriptionPoster presentation-
dc.description.abstractIn Injured nerves, chondroitin sulphate (CS) is upregulated forming barriers with astrocytes/fibroblasts and other extracellular matrix molecules, and thereby hampering nerve regeneration. Cleavage of CS using chondroitin sulphate lyases (Proteus vulgaris) promises axon regrowth through the barrier but the enzymatic efficacy remains to be improved. Two subtypes, endolyase and exolyase, have been found coexisting in the original host but only the former has been exploited for treatment of injured nerve tracts. We hypothesise that the two subtypes are necessary for enzymatic efficacy on CSs. We therefore prepared recombinant enzymes of both subtypes. Enzyme kinetics study revealed feedback inhibition by limit digestion products: that of the endolyase by tetrasaccharides and that of the exolyase by the disaccharides. When the two subtypes were used in combination, the digestion efficiency increased. We then used TGF beta-1 to induce CS production by astrocytes in culture, mimicking reactive glia in injured nerves. In co-cultures of such astrocytes with cortical neurons, treatment with combinations of the two subtypes resulted in increased neurite lengths as compared to co-cultures treated with one of the subtypes. The limit digestion products of CS were further tested for their effects on neurite extension on astrocytes that had been treated with TGF beta-1. The CS disaccharides, both 4- and 6-sulphated but not the tetrasaccharides, promoted neurite extension significantly. Taken together, the combinatorial use of the ChABC subtypes not only improved efficacy of enzyme activity on the axon-restrictive CS moiety, but also increased the yield of CS disaccharides which contributed to axonal growth.-
dc.languageengen_US
dc.relation.ispartofHong Kong-Taiwan Physiology Symposium and Joint Scientific Meeting of Hong Kong Society of Neurosciences & The Biophysical Society of Hong Kongen_US
dc.rightsCreative Commons: Attribution 3.0 Hong Kong License-
dc.titleThe Mechanisms of Chondroitin Sulphate Lyases Treatment in Promotion of Axonal Growthen_US
dc.typeConference_Paperen_US
dc.identifier.emailTam, KW: antam@graduate.hku.hken_US
dc.identifier.emailChan, YS: yschan@hku.hken_US
dc.identifier.emailShum, DKY: shumdkhk@hkucc.hku.hken_US
dc.identifier.authorityChan, YS=rp00318en_US
dc.identifier.authorityShum, DKY=rp00321en_US
dc.description.naturepublished_or_final_version-
dc.identifier.hkuros200594en_US
dc.identifier.spage72, abstract no. P57-
dc.identifier.epage73, abstract no. P57-
dc.publisher.placeHong Kong, China-

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