Most likely too late for Arnold Schwarzenegger! 😄 This is early stage research! Why does it take so long to research the obvious benefits of hibernation and their implication for humans?
"... Scientists in Japan have made a fascinating discovery in this space, demonstrating how human muscle cells can be infused with serum from hibernating black bears to not just prevent atrophy, but actively promote an increase in mass. ...
This new study focused on skeletal muscle, which is susceptible to wasting caused by immobility. ... the research team took cultured human skeletal muscle cells and infused them with serum drawn from the blood of hibernating black bears, which led to significant protein growth after 24 hours. Importantly, serum collected during the bears' active summer season did not induce these same effects. ..."
This new study focused on skeletal muscle, which is susceptible to wasting caused by immobility. ... the research team took cultured human skeletal muscle cells and infused them with serum drawn from the blood of hibernating black bears, which led to significant protein growth after 24 hours. Importantly, serum collected during the bears' active summer season did not induce these same effects. ..."
"... But what these key blood components are remain unknown. ...
The researchers attributed the diminished capacity of the muscles’ “destruction mechanism” to the suppressed expression of MuRF1 (Muscle RING-finger protein-1), the switch triggering the shredding of unused muscles. According to them, it is likely that suppression of MuRF1 expression was mediated by the activation of the Akt/FOXO3a (protein kinase B/Forkhead box class O 3a) axis responsible for the elevation of protein synthesis.
They also observed increased levels of the growth factor hormone IGF-1 (insulin-like growth factor-1) in the hibernating bear serum. The researchers identified it as a candidate upstream factor that induces activation of the Akt/FOXO3a axis. ..."
From the abstract:
"Hibernating bears remain in their dens for 5–7 months during winter and survive without eating or drinking while staying inactive. However, they maintain their physical functions with minimal skeletal muscle atrophy and metabolic dysfunction. In bears, resistance to skeletal muscle atrophy during hibernation is likely mediated by seasonally altered systemic factors that are independent of neuromuscular activity. To determine whether there are components in bear serum that regulate protein and energy metabolism, differentiated human skeletal muscle cells were treated with bear serum (5% in DMEM/Ham’s F-12, 24 h) collected during active summer (July) and hibernating winter (February) periods. ... Total protein content in cultured skeletal muscle cells was significantly increased following a 24 h treatment with hibernating bear serum. Although the protein synthesis rate was not altered, the expression of MuRF1 protein, a muscle-specific E3 ubiquitin ligase was significantly decreased along with a concomitant activation of Akt/FOXO3a signaling. Increased levels of insulin-like growth factor-1 (IGF-1) were also observed in hibernating bear serum. These observations suggest that protein metabolism in cultured human myotubes may be altered when incubated with hibernating bear serum, with a significant increase in serum IGF-1 and diminished MuRF1 expression, a potential target of Akt/FOXO3a signaling. A protein sparing phenotype in cultured muscle cells by treatment with hibernating bear serum holds potential for the development of methods to prevent human muscle atrophy and related disorders."
Fig 1. Alteration of total protein contents in cultured human skeletal muscle cells: Winter-hibernation period vs. summer-active period.
