Pompe mice have improved respiration during hypercapnic challenge following acute intermittent hypoxia

Pompe disease results in cardiorespiratory distress secondary to glycogen accumulation in the lysosomes of all muscle types and motor neurons. The only approved treatment is enzyme replacement therapy (ERT), which improves survival, however, it cannot completely correct skeletal muscle or motor neuron pathology, therefore respiratory failure persists. To prevent respiratory distress effectively in Pompe patients, there is a need to develop novel approaches that can improve respiratory muscle and motor neuron function. Acute intermittent hypoxia (AIH) is a non-invasive therapy capable of improving respiratory motor function and has has been successful in studies of spinal cord injury and ALS. The hypothesis of this study is that AIH will promote plasticity in skeletal muscle and motor neurons to improve respiration in Pompe mice.2-month-old Pompe and wildtype (WT) mice were exposed to 10 cycles of alternating room air (21% O2) and hypoxia (10% O2) for 5 minutes each, once per day for 7 consecutive days. After the initial week of exposures, mice were given a reminder dose twice per week. An additional group of Pompe and WT mice were only exposed to room air to serve as untreated controls. Mice underwent whole body plethysmography (WBP) immediately before and after the initial week of AIH exposure and again at 6 months of age. During WBP, unanesthetized mice were placed in a Plexiglas chamber and exposed to room air (21% O2) for 2 hours, during which a 5-minute baseline period of quiet breathing was recorded, then the mice were exposed to 3, 10-minute respiratory challenges, first hypoxic air (10% O2), then hypercapnic air (7% CO2), and finally hypoxic and hypercapnic air together. At 6 months of age, respiration (frequency, tidal volume, minute ventilation, and peak inspiratory flow) was slightly improved in Pompe mice receiving AIH during the hypercapnia and hypercapnia + hypoxia challenges compared to untreated Pompe mice. The next steps of this study include evaluating glycogen accumulation and subsequent pathology in the carotid bodies, characterizing proteins associated with hypoxia induced plasticity in the medulla and spinal cord, and analyzing the health and integrity of diaphragm neuromuscular junctions. Our conclusion is that AIH improved respiration under hypercapnia conditions in Pompe mice. NIH/NHLBI K99HL161420 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Duke Scholars

Author Mai ElMallah Pediatrics, Pulmonary and Sleep Medicine