Abstract: One aspect of the present invention is directed to search receptors based on the information of HN signaling pathways in order to find Humanin receptor or Humanin-like polypeptide receptor (HNR), and to reveal a mechanism of promoting or suppressing the intracellular signal transduction for neuroprotecting activity of HN and identify a compound involved in the mechanism. The aspect of the invention is directed to a method for screening of HNR agonist and HNR antagonist, to utilize the screened compound in development of a drug for the treatment of neurodegenerative disease, and to provide an assay system of AD neuronal cell death, and to provide methods for the compulsory expression of HNR gene or knocking-out of intracellular genes.

Abstract: The present invention relates to a pharmaceutical composition for the treatment and/or prevention of a neurodegenerative disease, comprising the following polypeptide shown in any of (a) to (c): (a) a polypeptide comprising the amino acid sequence represented by Ser-Ala-Leu-Leu-Arg-Ser-Ile-Pro-Ala-Pro-Ala-Gly-Ala-Ser-Arg-Leu-Leu-Leu-Leu-Thr-Gly-Glu-Ile-Asp-Leu-Pro (SEQ ID NO: 1); (b) a polypeptide comprising an amino acid sequence having a deletion, substitution, insertion, and/or addition of one or several amino acids in the amino acid sequence consisting of Ser-Ala-Leu-Leu-Arg-Ser-Ile-Pro-Ala-Pro-Ala-Gly-Ala-Ser-Arg-Leu-Leu-Leu-Leu-Thr-Gly-Glu-Ile-Asp-Leu-Pro (SEQ ID NO: 1), and having an activity that inhibits neuronal cell death associated with neurodegenerative disease; and (c) a modified polypeptide from the polypeptide (a) or (b), or a pharmaceutically acceptable salt thereof, as an effective ingredient.

Abstract: An object of the present invention is to provide an agent effective for the treatment and/or prevention of motor neuron disease such as amyotrophic lateral sclerosis (ALS). The present invention provides a therapeutic and/or preventive agent for motor neuron disease comprising the following oligopeptide shown in any of (a) to (c) or a pharmaceutically acceptable salt thereof as an active ingredient: (a) an oligopeptide consisting of the amino acid sequence represented by Ser-Ala-Leu-Leu-Arg-Ser-Ile-Pro-Ala (SEQ ID NO: 1); (b) an oligopeptide consisting of an amino acid sequence having a deletion, substitution, insertion, or addition of one or several amino acids in Ser-Ala-Leu-Leu-Arg-Ser-Ile-Pro-Ala (SEQ ID NO: 1), and having an activity that inhibits neuronal cell death caused by a mutant superoxide dismutase-1 gene; and (c) a modified oligopeptide from the oligopeptide (a) or (b).

Abstract: The present invention relates to a pharmaceutical composition for the treatment and/or prevention of a neurodegenerative disease, comprising the following polypeptide shown in any of (a) to (c): (a) a polypeptide comprising the amino acid sequence represented by Ser-Ala-Leu-Leu-Arg-Ser-Ile-Pro-Ala-Pro-Ala-Gly-Ala-Ser-Arg-Leu-Leu-Leu-Leu-Thr-Gly-Glu-Ile-Asp-Leu-Pro (SEQ ID NO: 1); (b) a polypeptide comprising an amino acid sequence having a deletion, substitution, insertion, and/or addition of one or several amino acids in the amino acid sequence consisting of Ser-Ala-Leu-Leu-Arg-Ser-Ile-Pro-Ala-Pro-Ala-Gly-Ala-Ser-Arg-Leu-Leu-Leu-Leu-Thr-Gly-Glu-Ile-Asp-Leu-Pro (SEQ ID NO: 1), and having an activity that inhibits neuronal cell death associated with neurodegenerative disease; and (c) a modified polypeptide from the polypeptide (a) or (b), or a pharmaceutically acceptable salt thereof, as an effective ingredient.

Abstract: Humanin (HN), which has the sequence: Met-Ala-Pro-Arg-Gly-Phe-Ser-Cys-Leu-Leu-Leu-Leu-Thr-Ser-Glu-Ile-Asp-Leu-Pro-Val-Lys-Arg-Arg-Ala, is a polypeptide that was identified by screening for molecules that suppress neuronal cell death induced by a gene mutant associated with an familial Alzheimer's disease. The present application provides polypeptides derived from Humanin, which contain one or more D-amino acids or phosphorylated amino acids, or amino acids that form a multimer. The HN derivatives are useful in protecting neuronal cells from cytotoxicity related to neurodegenerative diseases. With higher potency and resulting lower effective amounts, HN derivatives represent better therapeutic agents than the naturally occurring form of RN.