OBJECTIVETo study the molecular mechanism of GM(2) gangliosidosis.

METHODSThe skin fibroblasts from 4 patients with GM(2) gangliosidosis were subjected to culture. Enzyme activities assay, Western blot and immunocytochemical analysis were performed using the cultured fibroblasts.

RESULTSThe hexosaminidase (Hex) activities of 4 patients with GM(2) gangliosidosis were significantly decreased. The activities were 12% 3% 15% and 6% of control values, respectively. Western blot analysis indicated that the amount of Hex mature alpha- and beta- subunits (alpha m, beta m) was decreased in cells from patients 2 and 3, but only decreased alpha m was found in patient 1 and both alpha m and beta m were normal in cells from patient 4. Immunocytochemical analysis revealed the accumulated GM(2) ganglioside in cells from patients 1-4.

CONCLUSIONThe pathogenesis of GM(2) gangliosidosis was associated with deficiency of Hex alpha m and beta m and GM(2) activator caused by HEXA, HEXB and GM(2)A gene mutations.

Adult ; Blotting, Western ; Cells, Cultured ; Child, Preschool ; Female ; Gangliosidoses, GM2 ; enzymology ; pathology ; Hexosaminidase A ; Hexosaminidase B ; Humans ; Infant ; Male ; Protein Subunits ; metabolism ; beta-N-Acetylhexosaminidases ; metabolism

OBJECTIVETo design and make trial of a new therapy for Gaucher disease.

METHODSA substrate analogue of beta-Glc (glucocerebroside analogue, GCA) was used as a molecular chaperon. Normal and mutant skin fibroblasts were cultured with or without GCA. The activity of beta-Glc was assayed by fluorescent enzymologic techniques. The amount of beta-Glc was determined using Western blot. The beta -Glc was localized by double cell stain experiment. The degradation of glucocerebroside was assessed by thin layer chromatography (TLC) experiment using 14C-Serine.

RESULTSIt was found that GCA could enhance the activity and amount of beta-Glc with F213I mutation. It also promoted the beta-Glc with F213I mutation to the lysosome and accelerated the degradation of glucocerebroside.

CONCLUSIONThe low molecular compound analogous to beta-Glc substrate (GCA ) may be a new therapeutic strategy for Gaucher's disease with F213I mutation.

Amino Acid Substitution ; Blotting, Western ; Cells, Cultured ; Enzyme Induction ; drug effects ; Gaucher Disease ; drug therapy ; enzymology ; genetics ; Glucosylceramidase ; biosynthesis ; genetics ; metabolism ; Glucosylceramides ; metabolism ; pharmacology ; Humans ; Immunohistochemistry ; Mutation ; Substrate Specificity