Structural optimization of a CXCR2-directed antagonist that indirectly inhibits gamma-secretase and reduces Abeta.
Amyloid beta (Abeta), a key molecule in the pathogenesis of Alzheimer's disease (AD), is derived from the amyloid precursor protein (APP) by sequential proteolysis via beta- and gamma-secretases. Because of their role in generation of Abeta, these enzymes have emerged as important therapeutic targets for AD. In the case of gamma-secretase, progress has been made towards designing potent inhibitors with suitable pharmacological profiles. Direct gamma-secretase inhibitors are being evaluated in clinical trials and new strategies are being explored to block gamma-secretase activity indirectly as well. In this regard, we have previously reported an indirect regulation of gamma-secretase through antagonism of CXCR2, a G-protein coupled receptor (GPCR). We demonstrated that N-(2-hydroxy-4-nitrophenyl)-N'-(2-bromophenyl)urea (SB225002), a selective inhibitor of CXCR2 also plays a role in an indirect inhibition of gamma-secretase. Furthermore, we reported a approximately 5-fold difference in the selective inhibition of APP versus Notch processing via gamma-secretase following treatment with SB225002. Herein we describe the synthesis and optimization of SB225002. By determination of the structure-activity relationship (SAR), we derived small molecules that inhibit Abeta40 production with IC(50) values in the sub-micromolar range in a cell-based assay and also validated the potential of CXCR2 as a new target for therapeutic intervention in AD.
Bakshi
Pancham
P
Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, United States. pbakshi@rfdn.org
Jin
Chao
C
Broutin
Pierre
P
Berhane
Beniam
B
Reed
Jon
J
Mullan
Michael
M
D000544:Alzheimer Disease / Q000188:drug therapy*; D053829:Amyloid Precursor Protein Secretases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D020128:Inhibitory Concentration 50; D009682:Magnetic Resonance Spectroscopy; D010671:Phenylurea Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D023063:Receptors, Interleukin-8B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D017550:Spectroscopy, Fourier Transform Infrared; D013329:Structure-Activity Relationship
D016229:Amyloid beta-Peptides; D004791:Enzyme Inhibitors; D010671:Phenylurea Compounds; D023063:Receptors, Interleukin-8B; C112019:SB 225002; D053829:Amyloid Precursor Protein Secretases