Treatment agent for cognitive impairment induced by amyloid beta-protein, therapeutic agent for alzheimer's disease, and treatment method and pathological analysis method related to these

A method for treatment of cognitive impairment induced by amyloid β protein or Alzheimer's disease, comprising:

• a step of administering an effective amount of a peptide selected from the group consisting of the following (I) to (VI) to a mammal which developed cognitive impairment induced by amyloid β protein or Alzheimer's disease, or to an animal model thereof:
• (I) a peptide consisting of the amino acid sequence of SEQ ID NO:
• 1:
• VLSSQQFLHRGHQPPPEMAGHSLASSHRNSMIPSAAT (SEQ ID NO:
• 1);
• (II) a peptide which is the amino acid sequence of SEQ ID NO:
• 1 except that one to three amino acids are altered by any one or more of deletion, addition, substitution, and side-chain modification;
• (III) a peptide which is a partial sequence of the amino acid sequence of SEQ ID NO:
• 1, comprising the amino acid sequence of SEQ ID NO:
• 2:
• HRGHQPPPEMA (SEQ ID NO:
• 2);
• (IV) a peptide which is a partial sequence of the amino acid sequence of SEQ ID NO:
• 1, comprising the amino acid sequence of SEQ ID NO:
• 2 except that one or two amino acids are altered by any one or more of deletion, addition, substitution, and side-chain modification;
• (V) a peptide which is the amino acid sequence of SEQ ID NO:
• 2 and a total of 1 to 50 amino acids added to the N-terminus and/or the C-terminus of the amino acid sequence of SEQ ID NO:
• 2 (excluding amino acid sequences which are identical to all or part of the amino acid sequence of SEQ ID NO:
• 1);
• and
• (VI) a peptide which is the amino acid sequence of SEQ ID NO:
• 2, except that one or two amino acids are altered by any one or more of deletion, addition (excluding addition to the N-terminus and/or the C-terminus), substitution, and side-chain modification and a total of 1 to 50 amino acids are added to the N-terminus and/or the C-terminus of said altered amino acid sequence.