title: Inhibition of myostatin with emphasis on follistatin as a therapy for muscle disease.
abstract: In most cases, pharmacologic strategies to treat genetic muscle disorders and certain acquired disorders, such as sporadic inclusion body myositis, have produced modest clinical benefits. In these conditions, inhibition of the myostatin pathway represents an alternative strategy to improve functional outcomes. Preclinical data that support this approach clearly demonstrate the potential for blocking the myostatin pathway. Follistatin has emerged as a powerful antagonist of myostatin that can increase muscle mass and strength. Follistatin was first isolated from the ovary and is known to suppress follicle-stimulating hormone. This raises concerns for potential adverse effects on the hypothalamic-pituitary-gonadal axis and possible reproductive capabilities. In this review we demonstrate a strategy to bypass off-target effects using an alternatively spliced cDNA of follistatin (FS344) delivered by adeno-associated virus (AAV) to muscle. The transgene product is a peptide of 315 amino acids that is secreted from the muscle and circulates in the serum, thus avoiding cell-surface binding sites. Using this approach our translational studies show increased muscle size and strength in species ranging from mice to monkeys. Adverse effects are avoided, and no organ system pathology or change in reproductive capabilities has been seen. These findings provide the impetus to move toward gene therapy clinical trials with delivery of AAV-FS344 to increase size and function of muscle in patients with neuromuscular disease.
authors.affiliation: Center for Gene Therapy, Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205 USA.
authors.forename: Louise R
authors.initials: LR
authors.lastname: Rodino-Klapac
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Haidet
authors.forename: Janaiah
authors.initials: J
authors.lastname: Kota
authors.forename: Chalonda
authors.initials: C
authors.lastname: Handy
authors.forename: Brian K
authors.initials: BK
authors.lastname: Kaspar
authors.forename: Jerry R
authors.initials: JR
authors.lastname: Mendell
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D018076:DNA, Complementary / Q000008:administration & dosage; D000229:Dependovirus / Q000235:genetics; D038681:Follistatin / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology* / Q000627:therapeutic use*; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D051379:Mice; D008817:Mice, Mutant Strains; D009132:Muscles / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D009135:Muscular Diseases / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D055435:Myostatin / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D038681:Follistatin; D055435:Myostatin