Glycogen storage disease type III: A novel Agl knockout mouse model

Area of Science:

• Biochemistry
• Genetics
• Pathology

Background:

• Glycogen storage disease type III (GSDIII) is an autosomal recessive disorder caused by a deficiency in the glycogen debranching enzyme (AGL).
• Key features include hepatomegaly, hypoglycemia, hyperlipidemia, growth retardation, and progressive myopathy, neuropathy, and/or cardiomyopathy in adults.
• Currently, no cure exists for GSDIII.

Purpose of the Study:

• To develop and characterize a mouse model for GSDIII.
• To validate the Agl knockout mouse as a reliable model for studying disease mechanisms and potential therapies.

Main Methods:

• Generation of an Agl knockout mouse model by deleting specific protein domains.
• Assessment of phenotypic features including hepatomegaly, glycogen storage, tissue impairment, and physical activity.
• Biochemical and histological analyses, including electron microscopy.

Main Results:

• Agl knockout mice exhibited significant hepatomegaly without cirrhosis or adenomas.
• Increased glycogen storage was observed in multiple tissues, including the central nervous system, diaphragm, and tongue.
• Mice displayed impaired motor function, exercise intolerance, kyphosis, and accelerated respiratory rate due to diaphragm glycogen accumulation.

Conclusions:

• The generated Agl knockout mouse model effectively recapitulates the essential phenotypic features of human GSDIII.
• This model serves as a valuable tool for investigating GSDIII pathogenesis and evaluating therapeutic strategies.