Gfralpha1-containing neurite outgrowth promoter and pharmaceutical composition for inducing nerve regeneration

A composition for promoting neurite outgrowth for neurons of postnatal mammalian individuals, comprising at least one protein selected from the group consisting of the following a) to d), and an antibody that inhibits glial cell-derived neurotrophic factor (GDNF) function or a nucleic acid that suppresses GDNF expression:

• a) GFRα1,
• b) a GFRα1 mutant having an amino acid sequence having at least 90% sequence identity with an amino acid sequence of GFRα1, and having neurite outgrowth activity,
• c) a fusion protein having neurite outgrowth activity, formed by fusing GFRα1 or a GFRα1 mutant with another peptide, and
• d) a chemically modified protein having neurite outgrowth activity, formed by chemically modifying at least one amino acid residue in GFRα1, a GFRα1 mutant, or a fusion protein.

18:

• A method for treating nerve injury, the method comprising:
• administering an effective amount of at least one protein selected from the group consisting of the following a) to d):
• a) GDNF family receptor al (GFRα1),
• b) a GFRα1 mutant having an amino acid sequence having at least 90% sequence identity with an amino acid sequence of GFRα1, and having neurite outgrowth activity,
• c) a fusion protein having neurite outgrowth activity, formed by fusing GFRα1 or a GFRα1 mutant with another peptide, and
• d) a chemically modified protein having neurite outgrowth activity, formed by chemically modifying at least one amino acid residue in GFRα1, a GFRα1 mutant, or a fusion protein,
• to a postnatal mammalian individual with a nerve injury in which an effective amount of GDNF is not present at or near the site of the nerve injury.

25:

• A method for promoting neurite outgrowth for neurons of postnatal mammalian individuals, the method comprising:
• applying an effective amount of at least one protein selected from the group consisting of the following a) to d):
• a) GDNF family receptor α1 (GFRα1),
• b) a GFRα1 mutant having an amino acid sequence having at least 90% sequence identity with an amino acid sequence of GFRα1, and having neurite outgrowth activity,
• c) a fusion protein having neurite outgrowth activity, formed by fusing GFRα1 or a GFRα1 mutant with another peptide, and
• d) a chemically modified protein having neurite outgrowth activity, formed by chemically modifying at least one amino acid residue in GFRα1, a GFRα1 mutant, or a fusion protein,
• to the neurons which are under a condition in which an effective amount of GDNF is not present.