title: Caspase vinyl sulfone small molecule inhibitors prevent axonal degeneration in human neurons and reverse cognitive impairment in Caspase-6-overexpressing mice.
abstract: The activation of the aspartate-specific cysteinyl protease, Caspase-6, is proposed as an early pathogenic event of Alzheimer disease (AD) and Huntington's disease. Caspase-6 inhibitors could be useful against these neurodegenerative diseases but most Caspase-6 inhibitors have been exclusively studied in vitro or show acute liver toxicity in humans. Here, we assessed vinyl sulfone small molecule peptide caspase inhibitors for potential use in vivo.
  
  
  
  The IC50of NWL vinyl sulfone small molecule caspase inhibitors were determined on Caspase-1 to 10, and Caspase-6-transfected human colon carcinoma HCT116 cells. Inhibition of Caspase-6-mediated axonal degeneration was assessed in serum-deprived or amyloid precursor protein-transfected primary human CNS neurons. Cellular toxicity was measured by phase contrast microscopy, mitochondrial and lactate dehydrogenase colorimetric activity assays, or flow cytometry. Caspase inhibition was measured by fluorogenic activity assays, fluorescence microscopy, and western blot analyses. The effect of inhibitors on age-dependent cognitive deficits in Caspase-6 transgenic mice was assessed by the novel object recognition task. Liquid chromatography coupled to tandem mass spectrometry assessed the blood-brain barrier permeability of inhibitors in Caspase-6 mice.
  
  
  
  Vinyl sulfone NWL-117 caspase inhibitor has a higher selectivity against Caspase-6, -4, -8, -9, and -10 whereas NWL-154 has higher selectivity against Caspase-6, -8, and -10. The half-maximal inhibitory concentrations (IC50) of NWL-117 and NWL-154 is 192 nM and 100 nM against Caspase-6 in vitro, and 4.82 μM and 3.63 μM in Caspase-6-transfected HCT116 cells, respectively. NWL inhibitors are not toxic to HCT116 cells or to human primary neurons. NWL-117 and NWL-154 inhibit serum deprivation-induced Caspase-6 activity and prevent amyloid precursor protein-mediated neurite degeneration in human primary CNS neurons. NWL-117 crosses the blood brain barrier and reverses age-dependent episodic memory deficits in Caspase-6 mice.
  
  
  
  NWL peptidic vinyl methyl sulfone inhibitors are potent, non-toxic, blood-brain barrier permeable, and irreversible caspase inhibitors with neuroprotective effects in HCT116 cells, in primary human CNS neurons, and in Caspase-6 mice. These results highlight the therapeutic potential of vinyl sulfone inhibitors as caspase inhibitors against neurodegenerative diseases and sanction additional work to improve their selectivity against different caspases.
authors.affiliation: Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3999 Ch. Cote Ste-Catherine, Montreal, QC, H3T 1E2, Canada.|Department of Neurology and Neurosurgery, McGill University, 845 Sherbrooke O, Montreal, QC, H3A 0G4, Canada.
authors.forename: Prateep
authors.initials: P
authors.lastname: Pakavathkumar
authors.affiliation: Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3999 Ch. Cote Ste-Catherine, Montreal, QC, H3T 1E2, Canada.|Department of Neurology and Neurosurgery, McGill University, 845 Sherbrooke O, Montreal, QC, H3A 0G4, Canada.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Noël
authors.affiliation: Laboratory of Cerebrovascular Research, Montreal Neurological Institute, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
authors.forename: Clotilde
authors.initials: C
authors.lastname: Lecrux
authors.affiliation: Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3999 Ch. Cote Ste-Catherine, Montreal, QC, H3T 1E2, Canada.|Department of Neurology and Neurosurgery, McGill University, 845 Sherbrooke O, Montreal, QC, H3A 0G4, Canada.
authors.forename: Agne
authors.initials: A
authors.lastname: Tubeleviciute-Aydin
authors.affiliation: Laboratory of Cerebrovascular Research, Montreal Neurological Institute, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
authors.forename: Edith
authors.initials: E
authors.lastname: Hamel
authors.affiliation: New World Laboratories, 500 Boulevard Cartier Ouest, Laval, QC, H7V 5B7, Canada.
authors.forename: Jan-Eric
authors.initials: JE
authors.lastname: Ahlfors
authors.affiliation: Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3999 Ch. Cote Ste-Catherine, Montreal, QC, H3T 1E2, Canada. andrea.leblanc@mcgill.ca.|Department of Neurology and Neurosurgery, McGill University, 845 Sherbrooke O, Montreal, QC, H3A 0G4, Canada. andrea.leblanc@mcgill.ca.|Molecular and Regenerative Medicine Axis, Lady Davis Institute for Medical Research, Sir Mortimer B Davis Jewish General Hospital, 3755 ch. Côte Ste-Catherine, Montréal, QC, H3T 1E2, Canada. andrea.leblanc@mcgill.ca.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: LeBlanc
mesh_terms: D000818:Animals; D001369:Axons / Q000187:drug effects / Q000201:enzymology; D015153:Blotting, Western; D053178:Caspase 6 / Q000187:drug effects*; D061945:Caspase Inhibitors / Q000494:pharmacology*; D002853:Chromatography, Liquid; D003072:Cognition Disorders / Q000473:pathology; D004195:Disease Models, Animal; D005434:Flow Cytometry; D006801:Humans; D020128:Inhibitory Concentration 50; D051379:Mice; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D008858:Microscopy, Phase-Contrast; D009410:Nerve Degeneration / Q000473:pathology*; D009474:Neurons / Q000187:drug effects* / Q000201:enzymology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D013450:Sulfones / Q000494:pharmacology*; D053719:Tandem Mass Spectrometry
chemical_list: D061945:Caspase Inhibitors; D018696:Neuroprotective Agents; D013450:Sulfones; C009873:divinyl sulfone; D053178:Caspase 6
keywords: Alzheimer disease; Axonal degeneration; Caspase-6; Caspase-6 transgenic mice; Caspases; Peptide inhibitors; Primary human neurons; Vinyl sulfone inhibitors