title: Cambinol, a novel inhibitor of neutral sphingomyelinase 2 shows neuroprotective properties.
abstract: Ceramide is a bioactive lipid that plays an important role in stress responses leading to apoptosis, cell growth arrest and differentiation. Ceramide production is due in part to sphingomyelin hydrolysis by sphingomyelinases. In brain, neutral sphingomyelinase 2 (nSMase2) is expressed in neurons and increases in its activity and expression have been associated with pro-inflammatory conditions observed in Alzheimer's disease, multiple sclerosis and human immunodeficiency virus (HIV-1) patients. Increased nSMase2 activity translates into higher ceramide levels and neuronal cell death, which can be prevented by chemical or genetic inhibition of nSMase2 activity or expression. However, to date, there are no soluble, specific and potent small molecule inhibitor tool compounds for in vivo studies or as a starting point for medicinal chemistry optimization. Moreover, the majority of the known inhibitors were identified using bacterial, bovine or rat nSMase2. In an attempt to identify new inhibitor scaffolds, two activity assays were optimized as screening platform using the recombinant human enzyme. First, active hits were identified using a fluorescence-based high throughput compatible assay. Then, hits were confirmed using a 14C sphingomyelin-based direct activity assay. Pharmacologically active compounds and approved drugs were screened using this strategy which led to the identification of cambinol as a novel uncompetitive nSMase2 inhibitor (Ki = 7 μM). The inhibitory activity of cambinol for nSMase2 was approximately 10-fold more potent than for its previously known target, silence information regulator 1 and 2 (SIRT1/2). Cambinol decreased tumor necrosis factor-α or interleukin-1 β-induced increases of ceramide and cell death in primary neurons. A preliminary study of cambinol structure and activity allowed the identification of the main structural features required for nSMase2 inhibition. Cambinol and its analogs may be useful as nSMase2 inhibitor tool compounds to prevent ceramide-dependent neurodegeneration.
authors.affiliation: Brain Science Institute Drug Discovery Program, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Mariana
authors.initials: M
authors.lastname: Figuera-Losada
authors.affiliation: Brain Science Institute Drug Discovery Program, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Marigo
authors.initials: M
authors.lastname: Stathis
authors.affiliation: Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Joelle M
authors.initials: JM
authors.lastname: Dorskind
authors.affiliation: Brain Science Institute Drug Discovery Program, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Ajit G
authors.initials: AG
authors.lastname: Thomas
authors.affiliation: Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Veera Venkata Ratnam
authors.initials: VV
authors.lastname: Bandaru
authors.affiliation: Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Seung-Wan
authors.initials: SW
authors.lastname: Yoo
authors.affiliation: School of Chemistry and Biomedical Sciences Research Centre, University of Saint Andrews and EaStCHEM, North Haugh, Saint Andrews, Fife, KY16 9ST, United Kingdom.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Westwood
authors.affiliation: School of Chemistry and Biomedical Sciences Research Centre, University of Saint Andrews and EaStCHEM, North Haugh, Saint Andrews, Fife, KY16 9ST, United Kingdom.
authors.forename: Graeme W
authors.initials: GW
authors.lastname: Rogers
authors.affiliation: Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Justin C
authors.initials: JC
authors.lastname: McArthur
authors.affiliation: Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Richard T. Johnson Division of Neuroimmunology and Neurological Infections, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Norman J
authors.initials: NJ
authors.lastname: Haughey
authors.affiliation: Brain Science Institute Drug Discovery Program, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Barbara S
authors.initials: BS
authors.lastname: Slusher
authors.affiliation: Brain Science Institute Drug Discovery Program, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Camilo
authors.initials: C
authors.lastname: Rojas
mesh_terms: D000818:Animals; D002417:Cattle; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002518:Ceramides / Q000096:biosynthesis; D016207:Cytokines / Q000494:pharmacology; D003712:Dendrites / Q000187:drug effects / Q000473:pathology; D004353:Drug Evaluation, Preclinical; D057075:Enzyme Assays; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005453:Fluorescence; D057809:HEK293 Cells; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology; D009281:Naphthalenes / Q000737:chemistry / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D018696:Neuroprotective Agents / Q000737:chemistry / Q000494:pharmacology*; D011744:Pyrimidinones / Q000737:chemistry / Q000494:pharmacology*; D011851:Radioactivity; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000494:pharmacology; D013108:Sphingomyelin Phosphodiesterase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013329:Structure-Activity Relationship; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D002518:Ceramides; D016207:Cytokines; D004791:Enzyme Inhibitors; D053583:Interleukin-1beta; D009281:Naphthalenes; D018696:Neuroprotective Agents; D011744:Pyrimidinones; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; C510718:cambinol; D013108:Sphingomyelin Phosphodiesterase