PROJECT SUMMARY
Candidate & Environment: The short and long-term goals of the candidate are to gain skills, knowledge, and
experience necessary to become a successful independent investigator in gene therapy for neuromuscular
diseases (NMDs) with respiratory pathology, such as Pompe disease. Duke University is the optimal location for
the candidate to achieve these goals with a world-renowned Pompe disease clinical and research center, along
with myology and gene therapy experts, who frequently collaborate and who host monthly research seminars.
Research: Pompe disease is a fatal glycogen storage disease caused by mutations in the gene encoding acid
a-glucosidase (GAA), which is responsible for hydrolyzing lysosomal glycogen. GAA deficiency results in
glycogen accumulation in the lysosomes of muscles (cardiac, skeletal, smooth) and motor neurons. The only
FDA approved treatment is enzyme replacement therapy (ERT) of recombinant human GAA (rhGAA). ERT
effectively treats cardiac muscle glycogen accumulation but cannot completely correct skeletal muscle pathology
due to disrupted autophagy. In addition, ERT cannot cross the blood-brain barrier to treat motor neurons, and
therefore, respiratory failure persists. Thus, to prevent respiratory distress in Pompe patients, there is a need for
therapies that can clear glycogen and repair autophagy in the respiratory muscles and motor neurons. The
overall goal is to identify novel adjunctive therapies to improve respiratory muscle and motor neuron
pathology in Pompe disease. We propose to administer three autophagy activators which can cross the blood-
brain barrier and assess their therapeutic impact on the motor unit of Pompe mice (Gaa-/-). Acute intermittent
hypoxia (AIH), rapamycin, and recombinant adeno-associated virus (rAAV) gene therapy are potential therapies
to treat Pompe disease, which will be evaluated across three aims. Each therapeutic has a unique and
complementary ability to address autophagy, a critical component of Pompe disease cellular therapy, in key
respiratory muscles and motor neurons. (1) Hypoxia is an activator of the autophagosome initiation complex.
Additionally, AIH induces neuroplasticity in respiratory motor neurons in neurogenerative disorders. (2)
Rapamycin is currently administered to Pompe patients as an immune suppressor, however, rapamycin also has
a direct negative impact on master metabolic regulator, mTORC1, thus activating autophagy. (3) rAAV-GAA
provides the deficient enzyme, thereby reducing glycogen and improving lysosome health which is a key to
restoring normal autophagy. In the final aim of this proposal, we will combine rAAV-GAA therapy with AIH and
rapamycin to determine the cumulative effect. Key methods of analysis include neurophysiology to assess neural
output of respiratory nerves, whole body plethysmography to assess respiration, molecular proteomics analysis
for autophagy pathway proteins, and immunohistochemistry to identify cellular architecture of muscle and CNS.
These novel interventions are already used in clinical trials and have the potential to quickly translate to clinical
care in Pompe patients suffering from respiratory distress.