D21 IMMUNE PATHWAYS IN ACUTE LUNG INJURY AND FIBROSIS: Novel Non-Catalytic Substrate-Selective P38α-Specific Mapk Inhibitors With Endothelial-Stabilizing And Anti-Inflammatory Activity That Mitigates Experimental Acute Lung Injury

Background: p38 MAPK signaling is important in regulating lung inflammation and injury, but the currently available p38 catalytic inhibitors (e.g. SB203580), which target the kinase active site, were poorly effective and caused toxicity in clinical trials. Methods: We used CADD to search a 60,000 compound database for those that fit in a 10-amino-acid pocket near the p38a ED site. 20 compounds were screened for binding to p38a but not ERK2 using Differential Scanning Fluorimetry (DSF), then compared with SB203580 in assays of TNFa- and hyperthermia-induced 10 kDa dextran leak and IL-8-directed neutrophil transendothelial migration in human lung microvascular endothelial cells (HMVECLs), LPS-induced THP1 cytokine expression by qRT-PCR array, TNFa-induced gene expression in HMVECLs, and an intratracheal LPS-induced acute lung injury in mice.