Alpha-enolase plasminogen receptor in myogenesis

Area of Science:

• Cell Biology
• Biochemistry
• Physiology

Background:

• Plasmin is a key protease for fibrinolysis, activated by urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA).
• Alpha-enolase, a glycolytic enzyme, functions as a cell-surface receptor for plasminogen, localizing plasmin generation.
• uPA-dependent plasmin generation is essential for myogenesis and muscle regeneration.

Purpose of the Study:

• To investigate the role and expression of the alpha-enolase plasminogen receptor in myogenesis.
• To determine the impact of alpha-enolase on plasmin generation during muscle differentiation and regeneration.

Main Methods:

• Studied alpha-enolase expression in skeletal myoblasts during in vitro differentiation.
• Utilized a monoclonal antibody (MAb 11G1) to inhibit plasmin generation and assess its effect on myoblast fusion and differentiation.
• Analyzed plasmin activity and alpha-enolase expression in regenerating muscle of wild-type and mdx mice.

Main Results:

• Skeletal myoblasts express alpha-enolase, with expression significantly induced during differentiation.
• Inhibition of plasmin generation via MAb 11G1 completely blocked myoblast fusion and differentiation.
• Plasmin activity and alpha-enolase expression were elevated in regenerating and dystrophic muscles.

Conclusions:

• The plasminogen activation system is integral to skeletal myogenesis in vitro and in vivo.
• Alpha-enolase concentrates plasminogen on myoblast surfaces, enhancing plasmin generation for effective muscle repair.
• Alpha-enolase plays a critical role in myoblast differentiation and muscle regeneration.