Autoradiographic detection of mucopolysaccharide accumulation in single fibroblasts

Area of Science:

• Cell Biology
• Biochemistry
• Histology

Background:

• Acid mucopolysaccharides (glycosaminoglycans) accumulate in cells in certain genetic disorders.
• Mucopolysaccharidosis II (MPS II) is a lysosomal storage disease characterized by the accumulation of specific glycosaminoglycans.
• Accurate detection of cellular storage is crucial for diagnosis and research.

Purpose of the Study:

• To develop and validate an autoradiographic method for localizing acid mucopolysaccharides at the single-cell level.
• To assess the feasibility of this technique for identifying cellular storage in MPS II.
• To compare 35SO4 incorporation in normal fibroblasts and MPS II fibroblasts.

Main Methods:

• Culturing normal and MPS II fibroblasts with 35SO4.
• Rapid quenching, freeze-drying, osmium tetroxide fixation, and Epon embedding of cells.
• Autoradiography and grain counting on 2 µm sections.

Main Results:

• A significant difference (P < 0.001) in 35SO4 incorporation was observed in the perinuclear cytoplasm of MPS II cells compared to control cells.
• Autoradiography confirmed the ratio of labeled to unlabeled cells when mixed.
• The method demonstrated feasibility for single-cell detection of acid mucopolysaccharide storage.

Conclusions:

• The described autoradiographic technique is effective for detecting acid mucopolysaccharide storage in cultured cells.
• This method allows for the identification of storage at the single-cell level, aiding in the study of MPS II.
• The technique provides a valuable tool for research into lysosomal storage diseases.