MTTP as a Mediator of the Benefits of Exercise
MTTP is a longevity-associated gene involved in lipid metabolism and correlated with cardiovascular function. Here, researchers use flies to demonstrate that the fly version of MTTP, called mtp, is involved in the mechanisms by which exercise improves long-term cardiac health. It isn't clear as to how exactly MTTP or mtp is involved in the known set of mechanisms important to the pace of aging and cardiovascular health. That sort of deep dive into establishing connections between cellular processes occurs only after numerous studies have demonstrated an interesting correlation, and even then it is a slow and incremental process.
Microsomal triglyceride transfer protein (mtp) in Drosophila is a direct homolog of human MTTP (microsomal triglyceride transfer protein), a lipid transfer protein found in the liver and intestine. Given its role as a rate-limiting enzyme in lipid metabolism, MTP has been associated with human longevity, coronary artery disease, and other vascular diseases caused by adverse lipid profiles (peripheral vascular disease, renal vascular disease, and stroke), which account for a significant portion of human mortality.
Diastolic dysfunction is a major cardiac dysfunction, and an important predisposing factor is age. Although exercise training is often used for the prevention and treatment of cardiovascular disease nowadays, little is currently known about whether exercise interventions associated with the slowing of cardiac aging are related to mtp-related pathways.
In the present study, after establishing a Drosophila exercise model, we found that cardiac systolic function and mtp expression levels decline with aging in Drosophila. Besides, there is a strong association between age-related diastolic dysfunction and mtp expression levels. Importantly, endurance exercise improves age-related diastolic dysfunction and prolongs lifespan, possibly related to the upregulation of mtp expression, thereby enhancing lipid metabolism in aged Drosophila.