Pompe disease (glycogen storage disease type II) is a lysosomal storage disorder due to a mutation in the gene
that encodes acid alpha-glucosidase (GAA). GAA deficiency causes the excessive storage of lysosomal glycogen in
many cell types, leading to cell and, subsequently, tissue dysfunction. Cardiac, respiratory and skeletal muscles are the
most severely affected. Enzyme replacement therapy (ERT) with recombinant human GAA (rhGAA, Myozyme®, Genzyme,
Cambridge) is the only approved treatment for Pompe disease. A new therapeutic strategy was developed consisting of
delivering adeno-associated virus serotype 9 (AAV9) and serotype 10 (AAV10) vectors expressing human GAA into
cerebrospinal fluid of GAA-KO 6neo/6neo Pompe mice. The purpose of this work was to investigate synchrotron Fourier
transform infrared (sFT-IR) and deep ultraviolet (sDUV) microspectroscopies to detect new biomarkers of the disease and
the AAV gene therapy in the cardiac muscle, one of the most affected organs in Pompe disease. Multivariate statistics
applied to sFT-IR spectra between 4000 cm–1 and 950 cm–1 highlighted the potential of sFT-IR to discriminate Pompe (-/-),
Wild type and AAV-treated animals from C–H stretching vibrations of CH3, from C–O, C–N and C–C stretching vibrations of
amide I, II, III bands and from specific IR signature of the glycogen. Investigations performed by sDUV microscopy showed
a significant increase of the tryptophan autofluorescent signal in the right ventricle for the AAV9-treated Pompe mice. The
high-resolution sDUV microspectroscopy experiments suggested a correlation between the tryptophan-rich area and the
GAA-rich area. These unprecedented results demonstrate that high-resolution UV microspectroscopy can be a
complementary innovative approach to monitor the chemical change in label-free cardiac muscle section. Moreover, this
non-destructive technology can be applied to a small amount of tissue allowing therapeutic assessment from biopsy of
human patients.
Safety of Intradiaphragmatic Delivery of Adeno-Associated Virus-Mediated Alpha-Glucosidase (rAAV1-CMV-hGAA) Gene Therapy in Children Affected by Pompe Disease