TY - JOUR
T1 - Intracellular degradation of sulforhodamine-GM1
T2 - Use for a fluorescence-based characterization of GM2-gangliosidosis variants in fibroblasts and white blood cells
AU - Agmon, Vered
AU - Khosravi, Rami
AU - Marchesini, Sergio
AU - Dinur, Tama
AU - Dagan, Arie
AU - Gatt, Shimon
AU - Navon, Ruth
PY - 1996/3/29
Y1 - 1996/3/29
N2 - A novel fluorescent ganglioside, sulforhodamine-GM1 was administered into cells derived from carriers and patients with different subtypes of GM2 gangliosidosis, resulting from various mutations in the gene encoding the lysosomal enzyme hexosaminidase (Hex) A. The cells used were skin fibroblasts and white blood cells, i.e. lymphocytes, monocytes and macrophages. In the severe infantile form of the GM2 gangliosidosis, Tay-Sachs disease, the sulforhodamine-GM1 was hydrolyzed within the lysosomes to the corresponding sulforhodamine-GM2 which, because of lack of Hex A activity, was not further degraded. In comparison, in the cells derived from GM2 gangliosidoses carriers, as well as pseudodeficient and adult forms of GM2 gangliosidosis, the sulforhodamine-GM2 was further processed and sequentially degraded by the lysosomal glycosidases to sulforhodamme-ceramide. The latter was converted to sulforhodamine-sphingomyelin, which was secreted into the culture medium. The fluorescence of the sulforhodamine ceramide in cell extracts and/or sulforhodamine-sphingomyelin in the culture medium was quantified and related to parallel data obtained using cells of normal individuals. This permitted distinguishing between the various GM2 gangliosidoses subtypes and relating the intracellular hydrolysis of sulforhodamine-GM1 to the genotypes of the respective GM2 gangliosidoses variants.
AB - A novel fluorescent ganglioside, sulforhodamine-GM1 was administered into cells derived from carriers and patients with different subtypes of GM2 gangliosidosis, resulting from various mutations in the gene encoding the lysosomal enzyme hexosaminidase (Hex) A. The cells used were skin fibroblasts and white blood cells, i.e. lymphocytes, monocytes and macrophages. In the severe infantile form of the GM2 gangliosidosis, Tay-Sachs disease, the sulforhodamine-GM1 was hydrolyzed within the lysosomes to the corresponding sulforhodamine-GM2 which, because of lack of Hex A activity, was not further degraded. In comparison, in the cells derived from GM2 gangliosidoses carriers, as well as pseudodeficient and adult forms of GM2 gangliosidosis, the sulforhodamine-GM2 was further processed and sequentially degraded by the lysosomal glycosidases to sulforhodamme-ceramide. The latter was converted to sulforhodamine-sphingomyelin, which was secreted into the culture medium. The fluorescence of the sulforhodamine ceramide in cell extracts and/or sulforhodamine-sphingomyelin in the culture medium was quantified and related to parallel data obtained using cells of normal individuals. This permitted distinguishing between the various GM2 gangliosidoses subtypes and relating the intracellular hydrolysis of sulforhodamine-GM1 to the genotypes of the respective GM2 gangliosidoses variants.
KW - Fluorescent G ganglioside
KW - G ganglioside
KW - G gangliosidosis
KW - Lipid storage diseases
KW - Tay-Sachs disease
KW - β-N-acetyl hexosaminidase A
UR - http://www.scopus.com/inward/record.url?scp=0029670551&partnerID=8YFLogxK
U2 - 10.1016/0009-8981(96)85130-8
DO - 10.1016/0009-8981(96)85130-8
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AN - SCOPUS:0029670551
SN - 0009-8981
VL - 247
SP - 105
EP - 120
JO - Clinica Chimica Acta
JF - Clinica Chimica Acta
IS - 1-2
ER -