Screening and treatment methods using IGS5 enzymes of the metalloprotease family
Polypeptides which are related to the neprilysin enzyme family and have zinc metalloprotease activities and are referred to as IGS5, polynucleotides encoding such polypeptides, vectors containing such polynucleotides, host cells containing such vectors, processes for producing such polypeptides and/or polynucleotides, screening methods for identifying compounds which stimulate or inhibit IGS5 polypeptides and/or polynucleotides, and the use of such polypeptides and/or polynucleotides in therapy of various dysfunctions, disorders or diseases, particularly cardiovascular diseases, metabolic diseases such as diabetes mellitus type II, and neurodegenerative disorders, such as Parkinson's Disease.
1. A method for the treatment of a neurodegenerative disease in a mammalian subject, the method comprising the step of administering to said subject an effective amount of a compound inhibiting or decreasing activity of an neprilysin II (IGS5) polypeptide wherein said IGS5 polypeptide has a zinc metallopeptidase activity and comprises a human amino acid sequence having at least 95% sequence identity to SEQ ID NO:2, SEQ ID NO:4 or SEQ ID NO:6 and wherein said compound is selected from the group consisting of:
(i) Phosphoramidon;
(ii) (3S,2′R)-3-{1-[2′-(ethoxycarbonyl)-4′-phenylbutyl]-cyclopentane-1-carbonylamino}-2,3,4,5-tetrahydro-2-oxo-1H-1-benzazepine-1-acetic acid; and
(iii) a compound inhibiting expression of IGS5 selected from antisense sequences, oligonucleotides which form triple helices or ribozymes.
2. A method according to claim 1 , wherein the neurodegenerative disease is selected from the group consisting of Parkinson's disease, multiple sclerosis, Alzheimer disease, Huntington's disease, stroke, and cerebral ischemia.
3. A method according to claim 1 , wherein said compound is a selective inhibitor of said IGS5 polypeptide.
4. A method according to claim 1 , wherein said compound does not inhibit the activity of a neprisysin (NEP) polypeptide and/or endothelin converting enzyme-1 (ECE-1) polypeptide.
5. A method according to claim 1 , wherein said IGS5 polypeptide comprises an amino acid sequence having at least 99% sequence identity to SEQ ID NO:4 or SEQ ID NO:6.
6. The method according to claim 1 , wherein said neurodegenerative disease is associated with pituitary adenylate cyclase-activating polypeptide (PACAP) (1-27) levels decreased below normal baseline levels of PACAP(1-27).