Secret of hibernation: Bear blood protects against muscle breakdown
bears be able five to seven months of hibernation hold without eating and drinking. In humans, that’s enough three weeks of inactivity out, so that the Muscles begin to break down. A Japanese research team has now discovered why the bears have this extraordinary ability. The secret is in the blood of the animals and should now be made available to humans.
researchers of Hiroshima University in Japan found out why bears can survive long periods of inactivity with limited muscle loss and minimal metabolic disturbances. The findings, recently published in the renowned journal “PLOS ONE“ were presented could lead to new therapies against muscle wasting and metabolic disorders.
In humans, muscles break down quickly
Humans are not designed for long periods of inactivity. After just a few weeks without physical exertion, the body begins to breakdown of muscle mass and the build-up of adipose tissue. In the long term arises from lack of exercise an increased risk of obesity, Diabetes and heart diseases.
Bears survive months of inactivity unscathed
Hibernating bears survive long periods of inactivity without significant loss of physical ability. How bears manage to survive this phase unscathed has now been investigated by the Japanese working group at Hiroshima University.
Use it or lose it
“The phenomenon ‘use it or lose it’ (use it or lose it) is a recognized physiological principle for skeletal muscle, which is very plastic depending on the functional load”explains the first author of the study Professor Mitsunori Miyazaki.
“In many animal species, including humans, disuse typically leads to skeletal muscle wasting and metabolic disorders”adds Miyazaki.
Hibernating animals seem to have special resistances
“By contrast, hibernating animals are probably better described by the phenomenon ‘no use, but no lose’ (do nothing and still lose nothing)”, explains the scientist. These animal species seem a potential resistance to muscle wasting to possess during long periods of passivity.
Analysis of black bear blood
To unravel this mystery, the team analyzed the blood of hibernating Japanese black bears and discovered a key difference from the blood of non-hibernating mammals.
Muscle mass is determined by a dynamic balance
As the researchers explain, muscle mass is generally determined by the dynamic balance between the synthesis and breakdown of proteins. In the blood of hibernating bears, however, this balance was upset.
The scientists attributed this to a suppressed expression of a certain Proteins namens MuRF1 (Muscle RING-finger protein-1) that normally ensures that unused muscles are broken down.
In addition, the team was able to determine that the values of the growth factor hormone IGF-1 (insulin-like growth factor-1) was significantly increased in the serum of the wintering bears. This appears to be related to MuRF1 inhibition.
Bear blood serum acted on human cells
In another experiment, the working group made an astonishing discovery. They mixed the blood serum of the wintering black bears with human skeletal muscle cells. The cultured human muscle cells showed one after 24 hours of treatment significant protein growth.
However, when the blood serum of bears from the active summer period was used, this protein increase was not observed. The team thus confirms for the first time that the unique factors present in bears’ blood are only activated during hibernation and despite months of inactivity prevent muscle wasting.
Ability can be transferred to human cells
“We have suggested that some factor present in serum from wintering bears may regulate protein metabolism in cultured human skeletal muscle cells and contribute to the maintenance of muscle mass.”sums up Miyazaki.
The underlying mechanism is not yet sufficiently understood
However, the researchers have not yet been able to decode the exact mechanism underlying this process. The scientists involved hope that the clarification of this unexplored mechanism could lead to new therapies against muscle loss and revolutionize rehabilitation methods. (vb)
Author and source information
This text corresponds to the specifications of medical specialist literature, medical guidelines and current studies and has been checked by medical professionals.
Author:
Graduate editor (FH) Volker Blasek
Sources:
- Hiroshima University: Bears got hibernation power in their blood but identity of ‘superhero’ components still a mystery (veröffentlicht: 15.07.2022), hiroshima-u.ac.jp
- Mitsunori Miyazaki, Michito Shimozuru, Toshio Tsubota, et al.: Supplementing cultured human myotubes with hibernating bear serum results in increased protein content by modulating Akt/FOXO3a signaling; in: PLOS ONE (2022), journals.plos.org
Important NOTE:
This article contains general advice only and should not be used for self-diagnosis or treatment. He can not substitute a visit at the doctor.