Carotid Body Dysfunction Contributes to Respiratory Dysfunction in Rett Syndrome

Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in MECP2. Disordered breathing is a hallmark feature of RTT that negatively impacts quality of life and can be life-threatening. Despite this, mechanisms underlying disordered breathing in RTT are poorly understood. Although RTT is primarily considered a central nervous system disorder, we found that increased drive from peripheral respiratory chemoreceptors may contribute to unstable breathing in MeCP2 deficient mice. Consistent with this, breathing pure oxygen to limit output of peripheral chemoreceptors stabilized breathing in MeCP2 deficient mice. Also, knockdown of MeCP2 within the carotid body recapitulates RTT-like unstable breathing. We also found that MeCP2 deficiency alters the carotid body transcriptome, including disruption of genes involved in dopaminergic signaling; and treatment with a dopamine receptor agonist stabilized breathing in MeCP2 deficient mice. These results identify the peripheral chemoreceptors as high priority therapeutic targets for disordered breathing in RTT.