Blocking extracellular activation of myostatin as a strategy for treating muscle wasting

Area of Science:

• Biochemistry
• Molecular Biology
• Cellular Biology

Background:

• Growth factors are often bound to the extracellular matrix, requiring processing for cellular stimulation.
• Myostatin and GDF11, TGFβ family members, need dual proteolytic cleavage for activation.
• Targeting growth factor-receptor interactions for myostatin/GDF11 modulation is difficult.

Purpose of the Study:

• To develop a novel strategy for inhibiting myostatin and GDF11 signaling by blocking their release.
• To create human monoclonal antibodies that selectively target precursor forms of myostatin and GDF11.
• To demonstrate the therapeutic potential of blocking growth factor activation.

Main Methods:

• Development of human monoclonal antibodies against myostatin and GDF11 precursor forms.
• In vitro and in vivo testing of antibody efficacy in inhibiting signaling.
• Assessment of antibody effects on muscle atrophy and muscle performance in mice.

Main Results:

• Antibodies selectively binding precursor forms potently inhibited signaling in vitro and in vivo.
• A subset of antibodies blocked myostatin proteolytic activation, preventing muscle atrophy.
• The most effective myostatin antibodies significantly enhanced muscle growth and performance in healthy mice.

Conclusions:

• Inhibiting extracellular growth factor activation is a potent method for preventing signaling.
• This approach serves as a proof of concept for a new therapeutic strategy.
• The strategy is potentially applicable to other members of the TGFβ family.