Discovery, Synthesis, and Optimization of Diarylisoxazole-3-carboxamides as Potent Inhibitors of the Mitochondrial Permeability Transition Pore.
The mitochondrial permeability transition pore (mtPTP) is a Ca(2+) -requiring mega-channel which, under pathological conditions, leads to the deregulated release of Ca(2+) and mitochondrial dysfunction, ultimately resulting in cell death. Although the mtPTP is a potential therapeutic target for many human pathologies, its potential as a drug target is currently unrealized. Herein we describe an optimization effort initiated around hit 1, 5-(3-hydroxyphenyl)-N-(3,4,5-trimethoxyphenyl)isoxazole-3-carboxamide, which was found to possess promising inhibitory activity against mitochondrial swelling (EC50 <0.39 μM) and showed no interference on the inner mitochondrial membrane potential (rhodamine 123 uptake EC50 >100 μM). This enabled the construction of a series of picomolar mtPTP inhibitors that also potently increase the calcium retention capacity of the mitochondria. Finally, the therapeutic potential and in vivo efficacy of one of the most potent analogues, N-(3-chloro-2-methylphenyl)-5-(4-fluoro-3-hydroxyphenyl)isoxazole-3-carboxamide (60), was validated in a biologically relevant zebrafish model of collagen VI congenital muscular dystrophies.
University of Kansas Specialized Chemistry Center, 2304 Becker Drive, Lawrence, KS 66049 (USA).
Sudeshna
S
Roy
CNR Neuroscience Institute and Department of Biomedical Sciences, University of Padova, Padova, 35131 (Italy).
Justina
J
Šileikytė
CNR Neuroscience Institute and Department of Biomedical Sciences, University of Padova, Padova, 35131 (Italy).
Marco
M
Schiavone
University of Kansas Specialized Chemistry Center, 2304 Becker Drive, Lawrence, KS 66049 (USA).
Benjamin
B
Neuenswander
Department of Biology, University of Padova, Padova, 35131 (Italy).
Francesco
F
Argenton
University of Kansas Specialized Chemistry Center, 2304 Becker Drive, Lawrence, KS 66049 (USA).
Jeffrey
J
Aubé
Conrad Prebys Center for Chemical Genomics, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037 (USA).
Michael P
MP
Hedrick
Conrad Prebys Center for Chemical Genomics, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037 (USA).
Thomas D Y
TD
Chung
Vollum Institute, Oregon Health & Science University, Portland, OR 97239 (USA). forte@ohsu.edu.
Michael A
MA
Forte
CNR Neuroscience Institute and Department of Biomedical Sciences, University of Padova, Padova, 35131 (Italy). bernardi@bio.unipd.it.
Paolo
P
Bernardi
University of Kansas Specialized Chemistry Center, 2304 Becker Drive, Lawrence, KS 66049 (USA). schoenen@ku.edu.
Frank J
FJ
Schoenen
D002118:Calcium / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D055808:Drug Discovery; D006801:Humans; D007555:Isoxazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D033681:Mitochondrial Membrane Transport Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D015394:Molecular Structure; D013329:Structure-Activity Relationship
D007555:Isoxazoles; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; C000608761:N-(3-chloro-2-methylphenyl)-5-(4-fluoro-3-hydroxyphenyl)isoxazole-3-carboxamide; D002118:Calcium
calcium retention capacity; mitochondria; muscular dystrophy; permeability transition; zebrafish