title: Novel Noncatalytic Substrate-Selective p38α-Specific MAPK Inhibitors with Endothelial-Stabilizing and Anti-Inflammatory Activity.
abstract: The p38 MAPK family is composed of four kinases of which p38α/MAPK14 is the major proinflammatory member. These kinases contribute to many inflammatory diseases, but the currently available p38 catalytic inhibitors (e.g., SB203580) are poorly effective and cause toxicity. We reasoned that the failure of catalytic p38 inhibitors may derive from their activity against noninflammatory p38 isoforms (e.g., p38β/MAPK11) and loss of all p38α-dependent responses, including anti-inflammatory, counterregulatory responses via mitogen- and stress-activated kinase (MSK) 1/2 and Smad3. We used computer-aided drug design to target small molecules to a pocket near the p38α glutamate-aspartate (ED) substrate-docking site rather than the catalytic site, the sequence of which had only modest homology among p38 isoforms. We identified a lead compound, UM101, that was at least as effective as SB203580 in stabilizing endothelial barrier function, reducing inflammation, and mitigating LPS-induced mouse lung injury. Differential scanning fluorimetry and saturation transfer difference-nuclear magnetic resonance demonstrated specific binding of UM101 to the computer-aided drug design-targeted pockets in p38α but not p38β. RNA sequencing analysis of TNF-α-stimulated gene expression revealed that UM101 inhibited only 28 of 61 SB203580-inhibited genes and 7 of 15 SB203580-inhibited transcription factors, but spared the anti-inflammatory MSK1/2 pathway. We provide proof of principle that small molecules that target the ED substrate-docking site may exert anti-inflammatory effects similar to the catalytic p38 inhibitors, but their isoform specificity and substrate selectivity may confer inherent advantages over catalytic inhibitors for treating inflammatory diseases.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201.
authors.forename: Nirav G
authors.initials: NG
authors.lastname: Shah
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201.
authors.forename: Mohan E
authors.initials: ME
authors.lastname: Tulapurkar
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201.
authors.forename: Aparna
authors.initials: A
authors.lastname: Ramarathnam
authors.affiliation: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201.
authors.forename: Amanda
authors.initials: A
authors.lastname: Brophy
authors.affiliation: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201.
authors.forename: Ramon
authors.initials: R
authors.lastname: Martinez
authors.affiliation: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201.
authors.forename: Kellie
authors.identifier: 0000-0002-6030-4992
authors.initials: K
authors.lastname: Hom
authors.affiliation: University of Maryland Institute for Genome Science, Baltimore, MD 21201.
authors.forename: Theresa
authors.initials: T
authors.lastname: Hodges
authors.affiliation: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201.
authors.forename: Ramin
authors.identifier: 0000-0003-4976-8793
authors.initials: R
authors.lastname: Samadani
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201.
authors.forename: Ishwar S
authors.initials: IS
authors.lastname: Singh
authors.affiliation: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201.|Computer-Aided Drug Design Center, Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201; and.
authors.forename: Alexander D
authors.identifier: 0000-0001-8287-6804
authors.initials: AD
authors.lastname: MacKerell
authors.affiliation: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201.
authors.forename: Paul
authors.initials: P
authors.lastname: Shapiro
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201; jhasday@som.umaryland.edu.|Medicine and Research Services, Baltimore Veterans Administration Medical Center, Baltimore, MD 21201.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Hasday
mesh_terms: D055371:Acute Lung Injury / Q000473:pathology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D017076:Computer-Aided Design; D004195:Disease Models, Animal; D015195:Drug Design; D042783:Endothelial Cells / Q000187:drug effects*; D006801:Humans; D051379:Mice; D048308:Mitogen-Activated Protein Kinase 14 / Q000037:antagonists & inhibitors*; D008958:Models, Molecular; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*
chemical_list: D000893:Anti-Inflammatory Agents; D047428:Protein Kinase Inhibitors; D048308:Mitogen-Activated Protein Kinase 14