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The Inhibitory Core of the Myostatin Prodomain: Its Interaction with Both Type I and II Membrane Receptors, and Potential to Treat Muscle Atrophy.

Ohsawa Y, Takayama K, Nishimatsu S, Okada T, Fujino M, Fukai Y, Murakami T, Hagiwara H, Itoh F, Tsuchida K, Hayashi Y, Sunada Y - PLoS ONE (2015)

Bottom Line: We identified a 29-amino acid region that inhibited myostatin-induced transcriptional activity by 79% compared with the full-length prodomain.Moreover, intramuscular injection of p29 alleviated muscle atrophy and decreased the absolute force in caveolin 3-deficient limb-girdle muscular dystrophy 1C model mice.The injection suppressed activation of myostatin signaling and restored the decreased numbers of muscle precursor cells caused by caveolin 3 deficiency.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Kawasaki Medical School, Kurashiki, Okayama, 701-0192, Japan.

ABSTRACT
Myostatin, a muscle-specific transforming growth factor-β (TGF-β), negatively regulates skeletal muscle mass. The N-terminal prodomain of myostatin noncovalently binds to and suppresses the C-terminal mature domain (ligand) as an inactive circulating complex. However, which region of the myostatin prodomain is required to inhibit the biological activity of myostatin has remained unknown. We identified a 29-amino acid region that inhibited myostatin-induced transcriptional activity by 79% compared with the full-length prodomain. This inhibitory core resides near the N-terminus of the prodomain and includes an α-helix that is evolutionarily conserved among other TGF-β family members, but suppresses activation of myostatin and growth and differentiation factor 11 (GDF11) that share identical membrane receptors. Interestingly, the inhibitory core co-localized and co-immunoprecipitated with not only the ligand, but also its type I and type II membrane receptors. Deletion of the inhibitory core in the full-length prodomain removed all capacity for suppression of myostatin. A synthetic peptide corresponding to the inhibitory core (p29) ameliorates impaired myoblast differentiation induced by myostatin and GDF11, but not activin or TGF-β1. Moreover, intramuscular injection of p29 alleviated muscle atrophy and decreased the absolute force in caveolin 3-deficient limb-girdle muscular dystrophy 1C model mice. The injection suppressed activation of myostatin signaling and restored the decreased numbers of muscle precursor cells caused by caveolin 3 deficiency. Our findings indicate a novel concept for this newly identified inhibitory core of the prodomain of myostatin: that it not only suppresses the ligand, but also prevents two distinct membrane receptors from binding to the ligand. This study provides a strong rationale for the use of p29 in the amelioration of skeletal muscle atrophy in various clinical settings.

No MeSH data available.


Related in: MedlinePlus

p29 inhibits activation of intramuscular myostatin signaling in caveolin 3-deficient LGMD1C model mice.Immunoblot (n = 5). (A) and northern blot (n = 7). (B) analyses of TA muscles treated with or without p29 (upper). Densitometric analyses (lower). Values are mean ± SD fold increases compared with untreated wild-type muscles. *P < 0.05.
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pone.0133713.g009: p29 inhibits activation of intramuscular myostatin signaling in caveolin 3-deficient LGMD1C model mice.Immunoblot (n = 5). (A) and northern blot (n = 7). (B) analyses of TA muscles treated with or without p29 (upper). Densitometric analyses (lower). Values are mean ± SD fold increases compared with untreated wild-type muscles. *P < 0.05.

Mentions: To investigate the molecular mechanism by which p29 increases muscle mass, the levels of p-Smad2, the intracellular effector of myostatin, were analyzed in muscle homogenates (n = 5; Fig 9A). The amount of total Smad2 protein was comparable between wild-type and CAV3P104L mice with or without p29 treatment. In contrast, the level of p-Smad2 was significantly higher in untreated muscles from CAV3P104L mice. p29 treatment significantly reduced p-Smad2 levels in both wild-type and caveolin 3-deficient mice.


The Inhibitory Core of the Myostatin Prodomain: Its Interaction with Both Type I and II Membrane Receptors, and Potential to Treat Muscle Atrophy.

Ohsawa Y, Takayama K, Nishimatsu S, Okada T, Fujino M, Fukai Y, Murakami T, Hagiwara H, Itoh F, Tsuchida K, Hayashi Y, Sunada Y - PLoS ONE (2015)

p29 inhibits activation of intramuscular myostatin signaling in caveolin 3-deficient LGMD1C model mice.Immunoblot (n = 5). (A) and northern blot (n = 7). (B) analyses of TA muscles treated with or without p29 (upper). Densitometric analyses (lower). Values are mean ± SD fold increases compared with untreated wild-type muscles. *P < 0.05.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4520684&req=5

pone.0133713.g009: p29 inhibits activation of intramuscular myostatin signaling in caveolin 3-deficient LGMD1C model mice.Immunoblot (n = 5). (A) and northern blot (n = 7). (B) analyses of TA muscles treated with or without p29 (upper). Densitometric analyses (lower). Values are mean ± SD fold increases compared with untreated wild-type muscles. *P < 0.05.
Mentions: To investigate the molecular mechanism by which p29 increases muscle mass, the levels of p-Smad2, the intracellular effector of myostatin, were analyzed in muscle homogenates (n = 5; Fig 9A). The amount of total Smad2 protein was comparable between wild-type and CAV3P104L mice with or without p29 treatment. In contrast, the level of p-Smad2 was significantly higher in untreated muscles from CAV3P104L mice. p29 treatment significantly reduced p-Smad2 levels in both wild-type and caveolin 3-deficient mice.

Bottom Line: We identified a 29-amino acid region that inhibited myostatin-induced transcriptional activity by 79% compared with the full-length prodomain.Moreover, intramuscular injection of p29 alleviated muscle atrophy and decreased the absolute force in caveolin 3-deficient limb-girdle muscular dystrophy 1C model mice.The injection suppressed activation of myostatin signaling and restored the decreased numbers of muscle precursor cells caused by caveolin 3 deficiency.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Kawasaki Medical School, Kurashiki, Okayama, 701-0192, Japan.

ABSTRACT
Myostatin, a muscle-specific transforming growth factor-β (TGF-β), negatively regulates skeletal muscle mass. The N-terminal prodomain of myostatin noncovalently binds to and suppresses the C-terminal mature domain (ligand) as an inactive circulating complex. However, which region of the myostatin prodomain is required to inhibit the biological activity of myostatin has remained unknown. We identified a 29-amino acid region that inhibited myostatin-induced transcriptional activity by 79% compared with the full-length prodomain. This inhibitory core resides near the N-terminus of the prodomain and includes an α-helix that is evolutionarily conserved among other TGF-β family members, but suppresses activation of myostatin and growth and differentiation factor 11 (GDF11) that share identical membrane receptors. Interestingly, the inhibitory core co-localized and co-immunoprecipitated with not only the ligand, but also its type I and type II membrane receptors. Deletion of the inhibitory core in the full-length prodomain removed all capacity for suppression of myostatin. A synthetic peptide corresponding to the inhibitory core (p29) ameliorates impaired myoblast differentiation induced by myostatin and GDF11, but not activin or TGF-β1. Moreover, intramuscular injection of p29 alleviated muscle atrophy and decreased the absolute force in caveolin 3-deficient limb-girdle muscular dystrophy 1C model mice. The injection suppressed activation of myostatin signaling and restored the decreased numbers of muscle precursor cells caused by caveolin 3 deficiency. Our findings indicate a novel concept for this newly identified inhibitory core of the prodomain of myostatin: that it not only suppresses the ligand, but also prevents two distinct membrane receptors from binding to the ligand. This study provides a strong rationale for the use of p29 in the amelioration of skeletal muscle atrophy in various clinical settings.

No MeSH data available.


Related in: MedlinePlus