Antagonists of myostatin, a blood-borne negative regulator of muscle growth produced in muscle cells, have shown
considerable promise for enhancing muscle mass and strength in rodent studies and could serve as potential
therapeutic agents for human muscle diseases. One of the most potent of these agents,
follistatin, is both safe
and effective in mice, but similar tests have not been performed in nonhuman primates. To assess this important
criterion for clinical translation,
we tested an alternatively spliced form of human follistatin that affects skeletal muscle
but that has only minimal effects on nonmuscle cells. When injected into the quadriceps of cynomolgus macaque
monkeys, a follistatin isoform expressed from an adeno-associated virus serotype 1 vector, AAV1-FS344, induced
pronounced and durable increases in muscle size and strength. Long-term expression of the transgene did not produce
any abnormal changes in the morphology or function of key organs, indicating the safety of gene delivery by intramuscular
injection of an AAV1 vector. Our results, together with the findings in mice, suggest that therapy with AAV1-FS344
may improve muscle mass and function in patients with certain degenerative muscle disorders.
Follistatin Gene Delivery Enhances Muscle Growth and Strength in Nonhuman Primates ? Sci TM
The future is gonna be interesting...