fk-866 and Pneumonia

Our previous study indicated that overexpression of nicotinamide phosphoribosyltransferase (NAMPT) aggravated acute lung injury, while knockdown of NAMPT expression attenuated ventilator-induced lung injury. Recently, we found that meta-carborane-butyl-3-(3-pyridinyl)-2E-propenamide (MC-PPEA, MC4), in which the benzoylpiperidine moiety of FK866 has been replaced by a carborane, displayed a 100-fold increase in NAMPT inhibition over FK866. Here, we determined the effects of MC4 and FK866 on cecal ligation and puncture (CLP) surgery-induced sepsis in C57BL/6J mice. MC4 showed stronger inhibitory effects than FK866 on CLP-induced mortality, serum tumor necrosis factor α (TNFα) levels, pulmonary myeloperoxidase activity, alveolar injury, and interleukin 6 and interleukin1β messenger RNA levels. In vitro cell permeability and electric cell-substrate impedance sensing assays demonstrated that MC4 inhibited TNFα- and thrombin-mediated pulmonary endothelial cell permeability better than FK866. MC4 also exerted more potent effects than FK866, at concentrations as low as 0.3 nM, to attenuate TNFα-mediated intracellular cytokine expression, nicotinamide adenine dinucleotide (NAD+) and its reduced form NADH levels, and nuclear factor kappa B p65 phosphorylation and nuclear translocation in A549 cells. Our results strongly suggest that the newly developed MC4 is a more potent suppressor of CLP-induced pulmonary inflammation and sepsis than FK866, with potential clinical application as a new treatment agent for sepsis and inflammation.

Topics: Acrylamides; Acrylates; Animals; Boron Compounds; Cecum; Dose-Response Relationship, Drug; Humans; Ligation; Male; Mice; Mice, Inbred C57BL; Piperidines; Pneumonia; Sepsis; Structure-Activity Relationship; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha

We previously identified the intracellular nicotinamide phosphoribosyltransferase (iNAMPT, aka pre-B-cell colony enhancing factor) as a candidate gene promoting acute respiratory distress syndrome (ARDS) and ventilator-induced lung injury (VILI) with circulating nicotinamide phosphoribosyltransferase potently inducing NF-κB signaling in lung endothelium. iNAMPT also synthesizes intracellular nicotinamide adenine dinucleotide (iNAD) in response to extracellular oxidative stress, contributing to the inhibition of apoptosis via ill-defined mechanisms. We now further define the role of iNAMPT activity in the pathogenesis of ARDS/VILI using the selective iNAMPT inhibitor FK-866. C57/B6 mice were exposed to VILI (40 ml/kg, 4 h) or LPS (1.5 mg/kg, 18 h) after osmotic pump delivery of FK-866 (100 mg/kg/d, intraperitoneally). Assessment of total bronchoalveolar lavage (BAL) protein, polymorphonuclear neutrophil (PMN) levels, cytokine levels (TNF-α, IL-6, IL-1α), lung iNAD levels, and injury scores revealed that FK-866-mediated iNAMPT inhibition successfully reduced lung tissue iNAD levels, BAL injury indices, inflammatory cell infiltration, and lung injury scores in LPS- and VILI-exposed mice. FK-866 further increased lung PMN apoptosis, as reflected by caspase-3 activation in BAL PMNs. These findings support iNAMPT inhibition via FK-866 as a novel therapeutic agent for ARDS via enhanced apoptosis in inflammatory PMNs.

Topics: Acrylamides; Animals; Anti-Inflammatory Agents; Apoptosis; Bronchoalveolar Lavage Fluid; Caspase 3; Cytokines; Disease Models, Animal; Enzyme Inhibitors; Inflammation Mediators; Lung; Mice; Mice, Inbred C57BL; NAD; Neutrophils; Nicotinamide Phosphoribosyltransferase; Piperidines; Pneumonia; Respiratory Distress Syndrome; Ventilator-Induced Lung Injury