[Studies on the molecular mechanism of GM(2) gangliosidosis].
OBJECTIVE
To study the molecular mechanism of GM(2) gangliosidosis.


METHODS
The 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.


RESULTS
The 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.


CONCLUSIONS
The 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.
Hou
Lin
L
Medical College, Qingdao University, Qingdao  Shandong  266021 P. R. China. qdhoulin@yahoo.com
Kousaku
Ohno
O
D000328:Adult; D015153:Blotting, Western; D002478:Cells, Cultured; D002675:Child, Preschool; D005260:Female; D020143:Gangliosidoses, GM2 / Q000201:enzymology* / Q000473:pathology; D054818:Hexosaminidase A; D054819:Hexosaminidase B; D006801:Humans; D007223:Infant; D008297:Male; D021122:Protein Subunits / Q000378:metabolism; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism*
D021122:Protein Subunits; D054818:Hexosaminidase A; D054819:Hexosaminidase B; D001619:beta-N-Acetylhexosaminidases