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Glycogen storage disease type III (GSDIII) is a hereditary glycogenosis caused by deficiency of the glycogen debranching enzyme (GDE), an enzyme, encoded by Agl, enabling glycogen degradation by catalyzing alpha-1,4-oligosaccharide side chain transfer and alpha-1,6-glucose cleavage. GDE deficiency causes accumulation of phosphorylase-limited dextrin, leading to liver disorder followed by fatal myopathy. Here, we tested the capacity of the new autophagosomal activator GHF-201 to alleviate disease burden by clearing pathogenic glycogen surcharge in the GSDIII mouse model Agl−/−. We used open field, grip strength, and rotarod tests for evaluating GHF-201's effects on locomotion, a biochemistry panel to quantify hematological biomarkers, indirect calorimetry to quantify in vivo metabolism, transmission electron microscopy to quantify glycogen in muscle, and fibroblast image analysis to determine cellular features affected by GHF-201. GHF-201 was able to improve all locomotion parameters and partially reversed hypoglycemia, hyperlipidemia and liver and muscle malfunction in Agl−/− mice. Treated mice burnt carbohydrates more efficiently and showed significant improvement of aberrant ultrastructural muscle features. In GSDIII patient fibroblasts, GHF-201 restored mitochondrial membrane polarization and corrected lysosomal swelling. In conclusion, GHF-201 is a viable candidate for treating GSDIII as it recovered a wide range of its pathologies in vivo, in vitro, and ex vivo. [ABSTRACT FROM AUTHOR]

While the vast majority of Alzheimer's disease (AD) is non-familial, the animal models of AD that are commonly used for studying disease pathogenesis and development of therapy are mostly of a familial form. We aimed to generate a model reminiscent of the etiologies related to the common late-onset Alzheimer's disease (LOAD) sporadic disease that will recapitulate AD/dementia features. Naïve female mice underwent ovariectomy (OVX) to accelerate aging/menopause and were fed a high fat-sugar-salt diet to expose them to factors associated with increased risk of development of dementia/AD. The OVX mice fed a high fat-sugar-salt diet responded by dysregulation of glucose/insulin, lipid, and liver function homeostasis and increased body weight with slightly increased blood pressure. These mice developed AD-brain pathology (amyloid and tangle pathologies), gliosis (increased burden of astrocytes and activated microglia), impaied blood vessel density and neoangiogenesis, with cognitive impairment. Thus, OVX mice fed on a high fat-sugar-salt diet imitate a non-familial sporadic/environmental form of AD/dementia with vascular damage. This model is reminiscent of the etiologies related to the LOAD sporadic disease that represents a high portion of AD patients, with an added value of presenting concomitantly AD and vascular pathology, which is a common condition in dementia. Our model can, thereby, provide a valuable tool for studying disease pathogenesis and for the development of therapeutic approaches.