Abstract
Endurance exercise has broadly protective effects across organisms, increasing metabolic fitness and reducing incidence of several age-related diseases. Drosophila has emerged as a useful model for studying changes induced by chronic endurance exercise, as exercising flies experience improvements to various aspects of fitness at the cellular, organ and organismal level. The activity of octopaminergic neurons is sufficient to induce the conserved cellular and physiological changes seen following endurance training. All 4 octopamine receptors are required in at least one target tissue, but only one, Octβ1R, is required for all of them. Here, we perform tissue- and adult-specific knockdown of alpha- and beta-adrenergic octopamine receptors in several target tissues. We find that reduced expression of Octβ1R in adult muscles abolishes exercise-induced improvements in endurance, climbing speed, flight, cardiac performance and fat-body catabolism in male Drosophila. Importantly, Octβ1R and OAMB expression in the heart is also required cell-nonautonomously for adaptations in other tissues, such as skeletal muscles in legs and adult fat body. These findings indicate that activation of distinct octopamine receptors in skeletal and cardiac muscle are required for Drosophila exercise adaptations, and suggest that cell non-autonomous factors downstream of octopaminergic activation play a key role.
Highlights
Endurance exercise is a potent, low-cost intervention with broad healthspan-extending effects [1]
Norepinephrine secretion is known to be upregulated during an exercise bout, and affects multiple organ systems
We previously demonstrated that activation of neurons that secrete the invertebrate version of norepinephrine, octopamine, are necessary for fruit flies to respond to chronic exercise by increasing their endurance, speed and cardiac performance
Summary
Endurance exercise is a potent, low-cost intervention with broad healthspan-extending effects [1]. Chronic endurance training simultaneously promotes healthy physiology and prevents disease, improving function in heart, skeletal muscle and brain while reducing obesity, heart disease and cognitive decline [2,3,4] These benefits are associated with adaptive changes to gene expression and metabolism [2,5,6,7,8]. Trained male flies have increased mitophagy in cardiac and skeletal muscle [13], increased mitochondrial enzyme activity [11,14] and changes in transcript expression similar to those found in long-lived flies [5] These genetic and physiological adaptations closely resemble benefits seen in both rodent models [15] and humans [1]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
