Japanese scientists have found that exposing human muscle cells to serum produced by black bears during hibernation not only prevents the atrophy of these tissues but also promotes an increase in their mass.
A factor preventing muscle breakdown
While a few weeks of inactivity is enough to cause significant loss of muscle mass in humans, ours in hibernation can remain immobile for up to seven months without serious repercussions on their hibernation or their overall health. Not prone to heart disease, diabetes or cancer, these iconic animals gorge themselves on food during the summer and fall, in order to accumulate fat reserves that will allow them to spend the winter remaining largely inactive.
In the context of work published in the journal PLOS Oneresearchers from the universities of Hiroshima and Hokkaido exposed human skeletal muscle cells (sensitive to mass loss caused by immobility) to serum extracted from the blood of hibernating black bears and found that it ” dope literally these cells, unlike its counterpart collected during the summer season.
According to the team, such differences would be linked to the presence of a particular factor in the serum of hibernating bears, blocking the destruction mechanism (involving the protein MuRF1) at the origin of the degradation of musclesnormally occurring when these are not used for an extended period.
« This factor appears to regulate protein metabolism in cultured human skeletal muscle cells and contribute to the maintenance of muscle mass “, explains Mitsunori Miyazaki, lead author of the study. ” Their next steps will be to identify the hormones and pathways that suppress MuRF1. »
Effectively Prevent Muscle Loss in Men
Japanese researchers believe that such discoveries could lead to new treatments that can much more effectively prevent the loss of muscle mass during prolonged missions in the cosmos, as well as in the elderly, immobilized or sedentary.
« Since physical inactivity typically leads to skeletal muscle loss and metabolic dysfunction in many animal species, identifying this factor in the serum of hibernating bears and clarifying the mechanism preventing the muscles of these creatures from weakening would potentially avoid this scenario in humans Miyazaki concludes.