N-octyl-beta-valienamine up-regulates activity of F213I mutant beta-glucosidase in cultured cells: a potential chemical chaperone therapy for Gaucher disease.
Gaucher disease (GD) is the most common form of sphingolipidosis and is caused by a defect of beta-glucosidase (beta-Glu). A carbohydrate mimic N-octyl-beta-valienamine (NOV) is an inhibitor of beta-Glu. When applied to cultured GD fibroblasts with F213I beta-Glu mutation, NOV increased the protein level of the mutant enzyme and up-regulated cellular enzyme activity. The maximum effect of NOV was observed in F213I homozygous cells in which NOV treatment at 30 microM for 4 days caused a approximately 6-fold increase in the enzyme activity, up to approximately 80% of the activity in control cells. NOV was not effective in cells with other beta-Glu mutations, N370S, L444P, 84CG and RecNciI. Immunofluorescence and cell fractionation showed localization of the F213I mutant enzyme in the lysosomes of NOV-treated cells. Consistent with this, NOV restored clearance of 14C-labeled glucosylceramide in F213I homozygous cells. F213I mutant beta-Glu rapidly lost its activity at neutral pH in vitro and this pH-dependent loss of activity was attenuated by NOV. These results suggest that NOV works as a chemical chaperone to accelerate transport and maturation of F213I mutant beta-Glu and may suggest a therapeutic value of this compound for GD.
Lin
Hou
H
Department of Neurobiology, Division of Child Neurology, Tottori University Faculty of Medicine, 86 Nishi-machi, Yonago 683-850, Japan.
Sugimoto
Yuko
Y
Ohsaki
Yuki
Y
Ninomiya
Haruaki
H
Oka
Akira
A
Taniguchi
Miyako
M
Ida
Hiroyuki
H
Eto
Yoshikatsu
Y
Ogawa
Seiichiro
S
Matsuzaki
Yuji
Y
Sawa
Miwa
M
Inoue
Takehiko
T
Higaki
Katsumi
K
Nanba
Eiji
E
Ohno
Kousaku
K
Suzuki
Yoshiyuki
Y
D015153:Blotting, Western; D002478:Cells, Cultured; D005776:Gaucher Disease / Q000188:drug therapy*; D006595:Hexosamines / Q000494:pharmacology*; D006801:Humans; D015854:Up-Regulation / Q000187:drug effects*; D001617:beta-Glucosidase / Q000378:metabolism*
D006595:Hexosamines; C116532:N-octyl-beta-valienamine; D001617:beta-Glucosidase