LY-411575

LY-411575 is a potent  inhibitor of γ-secretase with IC50 value of 0.078 nM in membrane assay.[1]
γ-Secertase is one of intramenbrane-cleaving aspartyl protease which cleaves many type-I membrane proteins and many of them have important biological functions. γ-Secretase is a multi-subunit protease and it contains presenilin, nicastrin, APH-1(Anterior Pharynx- defective 1) and PEN-2. Presenilin contains Asp258 and Asp385 embedded in the sixth and seventh transmembrane domain and forms the active site. The feature of being a membrane integrated protease complex makes it difficult to be purified as well as studying its mechanism.γ-secretase is responsible for the generation Aβfrom the amyloid precursor protein.γ-Secertase has been considered as an important drug target for Alzheimer's disease.γ-Secertase also is responsible for Notch processing which is related to cancer such as leukemia.[2]
LY-411,575 significantly inhibits theγ-secretase activity in vitro. LY-411,575 inhibits the production of Aβproduction with IC50 value of 0.078 nM in membrane-assay and 0.082 nM in cell-basedγ-secretase assays, respectively. LY-411,575 also affects the Notch pathway by inhibiting Notch S3 cleavage with IC50 value of 0.39 nM.[1] LY-411,575 treatment also significantly inhibited the Notch pathway by inhibiting the γ-secretase activity luciferase activity in primary KS cells. LY-411,575 also induced the apoptosis though Notch pathway inhibition in primary and immortalized Kaposi's sarcoma (KS) tumor cells.[2]
LY-411,575 decreases the levels of brain and plasma Aβ40 and -42 at 10 mg/kg oral doses.[1] LY-411,575 also decreases cortical Aβ40 levels in transgenic CRND8 mice with ED50 ≈ 0.6 mg/kg. LY-411,575 also induced significantly intestinal goblet cell hyperplasia and thymus atrophy by inhibiting Notch signaling pathway at higher doses in vivo.[3]
References:
1.Wong GT, Manfra D, Poulet FM, Zhang Q, Josien H, Bara T, Engstrom L, Pinzon-Ortiz M, Fine JS, Lee HJ et al: Chronic treatment with the gamma-secretase inhibitor LY-411,575 inhibits beta-amyloid peptide production and alters lymphopoiesis and intestinal cell differentiation. J Biol Chem 2004, 279(13):12876-12882.
2.Curry CL, Reed LL, Golde TE, Miele L, Nickoloff BJ, Foreman KE: Gamma secretase inhibitor blocks Notch activation and induces apoptosis in Kaposi's sarcoma tumor cells. Oncogene 2005, 24(42):6333-6344.
3.Hyde LA, McHugh NA, Chen J, Zhang Q, Manfra D, Nomeir AA, Josien H, Bara T, Clader JW, Zhang L et al: Studies to investigate the in vivo therapeutic window of the gamma-secretase inhibitor N2-[(2S)-2-(3,5-difluorophenyl)-2-hydroxyethanoyl]-N1-[(7S)-5-methyl-6-oxo-6,7-di hydro-5H-dibenzo[b,d]azepin-7-yl]-L-alaninamide (LY411,575) in the CRND8 mouse. J Pharmacol Exp Ther 2006, 319(3):1133-1143.