Researchers at the Max Planck Institute for Biology of Ageing have made a groundbreaking discovery in their study of killifish that could have important implications for human aging. The study, which focused on the effects of fasting and refeeding on older fish, revealed that changes in adipose tissue lead to older fish being stuck in a fasting state, even when they are ingesting food.
The findings, published in the journal Nature Aging, showed that activating a specific subunit of AMP kinase, an important cellular energy sensor, restored the health and longevity of the older fish. This suggests that new methods for promoting healthier aging in humans could be on the horizon.
The study aimed to understand why fasting interventions, which involve alternating periods of fasting and refeeding, do not work as well in older animals. By studying the short-lived killifish, researchers found that older fish deviate from a youthful fasting and refeeding cycle, instead entering a state of perpetual fasting, even when they are ingesting food.
The researchers observed that the visceral adipose tissue of old fish became less responsive to feeding, leading the fish into a permanent state of fasting where energy metabolism is shut down, protein production is reduced, and tissue is not renewed.
However, when the activity of a specific subunit of AMP kinase was increased through genetic modification, the fasting-like state in the old fish was counteracted, leading to improved health and longevity.
The study also found a link between the specific subunit of AMP kinase and human aging. Lower levels of the subunit were measured in samples from elderly patients, and it was discovered that the less frail a person is in old age, the higher the level of the subunit.
Commenting on the findings, Adam Antebi, Director at the Max Planck Institute for Biology of Ageing and leader of the study, stated, “Of course, we don’t yet know whether in humans the subunit is actually responsible for healthier aging. In the next step, we will try to find molecules that activate precisely this subunit and investigate whether we can use them to positively influence aging.”
The study sheds light on the role of adipose tissue and AMP kinase in the aging process and could pave the way for new strategies to promote healthier aging in humans. It demonstrates the potential for genetic interventions to counteract the negative effects of aging and offers hope for new approaches to tackling age-related health issues.