A special amino acid has a significant influence on our internal clock (circadian rhythm) and glucose regulation. It could play a key role in healthy sleep and healthy blood sugar levels.
In a recent study on mice, a research team from Osaka University demonstrated that the amino acid D-alanine influences the circadian clock and glucose metabolism in the kidney. The corresponding study results are published in the specialist magazine “Kindey360”.
Amino acids in two forms
Amino acids, the building blocks of proteins, exist in two different forms, the L and the D form, the researchers explain. While all natural proteins consist exclusively of L-amino acids, the function of D-amino acids is still poorly understood, even though they occur in the food we eat every day.
One of these D-amino acids is D-alanine. According to the experts, it was already known from previous studies that trace levels of D-alanine in blood and urine vary with the circadian rhythm and that the so-called gluconeogenesis (metabolic pathway for the formation of glucose) also fluctuates in the course of the circadian rhythm.
In extensive studies, the researchers have now been able to demonstrate that the D-alanine level changes reliably with the circadian clock and that the fluctuations are caused by the removal of D-alanine via the urine, a process that is controlled by the kidneys.
The team also found that sleep appears to play a key role in regulating D-alanine levels.
Activation of genes examined
The researchers also analyzed which genes are expressed when the kidney is exposed to D-alanine.
“We found that D-alanine upregulates both genes associated with gluconeogenesis and genes known to be related to circadian rhythms,” explains Shinsuke Sakai from the Osaka University Graduate School of Medicine .
Treatment with D-alanine also eliminated disruptions in the mice’s circadian rhythm.
Can new treatment approaches be derived?
“Through these experiments, we were able to show that D-alanine represents a connection between gluconeogenesis in the kidney and the circadian clock,” summarizes Tomonori Kimura from the Osaka University Graduate School of Medicine. D-alanine activates gluconeogenesis via the circadian transcription network.
The discovered connection between D-alanine and the circadian rhythm also opens up exciting options for new treatment approaches against diseases related to glucose metabolism (diabetes) and the internal clock (sleep disorders). (fp)