Group of scientists reported a tremendously interesting study on skeletal muscle aging.
It is known that skeletal muscle undergoes a progressive age-related loss in mass and function.
Preservation of muscle mass depends in part on satellite cells, the resident stem cells of skeletal muscle.
Reduced satellite cell function may contribute to the age-associated decrease in muscle mass.
The scientists focused on characterizing the effect of age on satellite cell migration.
They reported that aged satellite cells migrate at less than half the speed of young cells.
In addition, aged cells show abnormal membrane extension and retraction characteristics required for amoeboid-based cell migration.
Aged satellite cells displayed low levels of integrin expression.
By deploying a mathematical model approach to investigate mechanism of migration, the scientists have found that young satellite cells move in a random "memoryless" manner, whereas old cells demonstrate superdiffusive tendencies.
Most importantly, they show that nitric oxide, a key regulator of cell migration, reversed the loss in migration speed and reinstated the unbiased mechanism of movement in aged satellite cells.
Finally, they found that although hepatocyte growth factor increased the rate of aged satellite cell movement, it did not restore the memoryless migration characteristics displayed in young cells.
This study shows that satellite cell migration, a key component of skeletal muscle regeneration, is compromised during aging.
However, it is proposed that clinically approved drugs could be used to overcome these detrimental changes.