Abstract |
Follistatin is an endogenous glycoprotein that promotes growth and repair of skeletal muscle by sequestering inhibitory ligands of the transforming growth factor-β superfamily and may therefore have therapeutic potential for neuromuscular diseases. Here, we sought to determine the suitability of a newly engineered follistatin fusion protein (FST288-Fc) to promote localized, rather than systemic, growth of skeletal muscle by capitalizing on the intrinsic heparin-binding ability of the follistatin-288 isoform. As determined by surface plasmon resonance and cell-based assays, FST288-Fc binds to activin A, activin B, myostatin (growth differentiation factor GDF8), and GDF11 with high affinity and neutralizes their activity in vitro. Intramuscular administration of FST288-Fc in mice induced robust, dose-dependent growth of the targeted muscle but not of surrounding or contralateral muscles, in contrast to the systemic effects of a locally administered fusion protein incorporating activin receptor type IIB (ActRIIB-Fc). Furthermore, systemic administration of FST288-Fc in mice did not alter muscle mass or body composition as determined by NMR, which again contrasts with the pronounced systemic activity of ActRIIB-Fc when administered by the same route. Subsequent analysis revealed that FST288-Fc in the circulation undergoes rapid proteolysis, thereby restricting its activity to individual muscles targeted by intramuscular administration. These results indicate that FST288-Fc can produce localized growth of skeletal muscle in a targeted manner with reduced potential for undesirable systemic effects. Thus, FST288-Fc and similar agents may be beneficial in the treatment of disorders with muscle atrophy that is focal, asymmetric, or otherwise heterogeneous.
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Authors | Roselyne Castonguay, Jennifer Lachey, Samantha Wallner, Jamie Strand, Katia Liharska, Abigail E Watanabe, Marishka Cannell, Monique V Davies, Dianne Sako, Megan E Troy, Lavanya Krishnan, Aaron W Mulivor, Huiming Li, Sarah Keates, Mark J Alexander, R Scott Pearsall, Ravi Kumar |
Journal | The Journal of pharmacology and experimental therapeutics
(J Pharmacol Exp Ther)
Vol. 368
Issue 3
Pg. 435-445
(03 2019)
ISSN: 1521-0103 [Electronic] United States |
PMID | 30563942
(Publication Type: Journal Article)
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Copyright | Copyright © 2019 The Author(s). |
Chemical References |
- Follistatin
- Immunoglobulin G
- Recombinant Fusion Proteins
- follistatin, 288-amino acid isoform
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Topics |
- Amino Acid Sequence
- Animals
- Dose-Response Relationship, Drug
- Follistatin
(administration & dosage, genetics, metabolism)
- Humans
- Immunoglobulin G
(administration & dosage, genetics, metabolism)
- Injections, Intramuscular
- Male
- Mice
- Mice, Inbred C57BL
- Muscle, Skeletal
(drug effects, growth & development, metabolism)
- Protein Structure, Secondary
- Recombinant Fusion Proteins
(administration & dosage, genetics, metabolism)
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