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Suppression of glypican-1 autodegradation by NO-deprivation correlates with nuclear accumulation of amyloid beta in normal fibroblasts.

Cheng, Fang LU ; Fransson, Lars-Åke LU and Mani, Katrin LU (2015) In Glycoconjugate Journal 32(9). p.675-684
Abstract
Heparan sulfate (HS)-containing, S-nitrosylated (SNO) glypican-1 (Gpc-1) releases anhydromannose-containing HS (anMan-HS) by SNO-catalyzed autodegradation in endosomes. Transport of anMan-HS to the nucleus requires processing of the amyloid precursor protein (APP) to amyloid beta peptides (Aβ). To further examine the relationship between APP and Gpc-1 processing in normal fibroblasts we have suppressed Gpc-1 autodegradation by aminoguanidine inhibition of NO synthesis and prevented lysosomal degradation of anMan-HS by using chloroquine. Deconvolution immunofluorescence microscopy and SDS-PAGE using anMan- and APP/Aβ-specific antibodies and markers for nuclei and autophagosomes were used to identify subcellular localization of Aβ and its... (More)
Heparan sulfate (HS)-containing, S-nitrosylated (SNO) glypican-1 (Gpc-1) releases anhydromannose-containing HS (anMan-HS) by SNO-catalyzed autodegradation in endosomes. Transport of anMan-HS to the nucleus requires processing of the amyloid precursor protein (APP) to amyloid beta peptides (Aβ). To further examine the relationship between APP and Gpc-1 processing in normal fibroblasts we have suppressed Gpc-1 autodegradation by aminoguanidine inhibition of NO synthesis and prevented lysosomal degradation of anMan-HS by using chloroquine. Deconvolution immunofluorescence microscopy and SDS-PAGE using anMan- and APP/Aβ-specific antibodies and markers for nuclei and autophagosomes were used to identify subcellular localization of Aβ and its oligomeric state. Wild-type mouse embryonic fibroblasts (WT MEF) grown during NO-deprivation accumulated 95-98 % of Aβ as oligomers in the nucleus. WT MEF treated with chloroquine accumulated both anMan-HS and Aβ, first in the nucleus then in autophagosomes. Maximal nuclear anMan-HS and Aβ accumulation was obtained after 4 and 7 h of growth, respectively. Both yielded similar banding patterns on SDS-PAGE which were also similar to the Aβ oligomers obtained after NO-deprivation. Nuclear Aβ accumulation was marginally increased (from 54 to 58 %) by suppression of both release and degradation of anMan-HS. Nuclear exit of Aβ, accumulated during growth in aminoguanidine, was enhanced by ascorbate-induced reactivation of anMan-HS production. Transgenic Alzheimer disease mouse (Tg2576) MEF, which produces excess amount of Aβ was used for comparison. Overall, nuclear Aβ exit and lysosomal degradation was compromised by inhibition of the autophagosome-lysosome pathway in both WT and Tg2576 MEF, while only WT MEF was sensitive to suppression of Gpc-1 autodegradation. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Glycoconjugate Journal
volume
32
issue
9
pages
675 - 684
publisher
Springer
external identifiers
  • pmid:26318599
  • wos:000365281700003
  • scopus:84947617998
ISSN
1573-4986
DOI
10.1007/s10719-015-9616-4
language
English
LU publication?
yes
id
91894542-d941-4606-a91e-c8ee8f8a1b51 (old id 8043775)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/26318599?dopt=Abstract
date added to LUP
2015-10-08 17:57:40
date last changed
2017-01-01 03:21:22
@article{91894542-d941-4606-a91e-c8ee8f8a1b51,
  abstract     = {Heparan sulfate (HS)-containing, S-nitrosylated (SNO) glypican-1 (Gpc-1) releases anhydromannose-containing HS (anMan-HS) by SNO-catalyzed autodegradation in endosomes. Transport of anMan-HS to the nucleus requires processing of the amyloid precursor protein (APP) to amyloid beta peptides (Aβ). To further examine the relationship between APP and Gpc-1 processing in normal fibroblasts we have suppressed Gpc-1 autodegradation by aminoguanidine inhibition of NO synthesis and prevented lysosomal degradation of anMan-HS by using chloroquine. Deconvolution immunofluorescence microscopy and SDS-PAGE using anMan- and APP/Aβ-specific antibodies and markers for nuclei and autophagosomes were used to identify subcellular localization of Aβ and its oligomeric state. Wild-type mouse embryonic fibroblasts (WT MEF) grown during NO-deprivation accumulated 95-98 % of Aβ as oligomers in the nucleus. WT MEF treated with chloroquine accumulated both anMan-HS and Aβ, first in the nucleus then in autophagosomes. Maximal nuclear anMan-HS and Aβ accumulation was obtained after 4 and 7 h of growth, respectively. Both yielded similar banding patterns on SDS-PAGE which were also similar to the Aβ oligomers obtained after NO-deprivation. Nuclear Aβ accumulation was marginally increased (from 54 to 58 %) by suppression of both release and degradation of anMan-HS. Nuclear exit of Aβ, accumulated during growth in aminoguanidine, was enhanced by ascorbate-induced reactivation of anMan-HS production. Transgenic Alzheimer disease mouse (Tg2576) MEF, which produces excess amount of Aβ was used for comparison. Overall, nuclear Aβ exit and lysosomal degradation was compromised by inhibition of the autophagosome-lysosome pathway in both WT and Tg2576 MEF, while only WT MEF was sensitive to suppression of Gpc-1 autodegradation.},
  author       = {Cheng, Fang and Fransson, Lars-Åke and Mani, Katrin},
  issn         = {1573-4986},
  language     = {eng},
  number       = {9},
  pages        = {675--684},
  publisher    = {Springer},
  series       = {Glycoconjugate Journal},
  title        = {Suppression of glypican-1 autodegradation by NO-deprivation correlates with nuclear accumulation of amyloid beta in normal fibroblasts.},
  url          = {http://dx.doi.org/10.1007/s10719-015-9616-4},
  volume       = {32},
  year         = {2015},
}