ABSTRACT
We investigated the effects of LASSBio-998 (L-998), a compound designed to be a p38 MAPK (mitogen-activated protein kinase) inhibitor, on lipopolysaccharide (LPS)-induced acute lung inflammation in vivo. BALB/c mice were challenged with aerosolized LPS inhalation (0.5 mg/ml) 4 h after oral administration of L-998. Three hours after LPS inhalation, bronchoalveolar lavage fluid was obtained to measure the levels of the proinflammatory cytokines TNF-α (tumor necrosis factor-α) and IL-1 (interleukin-1) and the chemokines MCP-1 (monocyte chemoattractant protein-1) and KC (keratinocyte chemoattractant). In addition, neutrophil infiltration and p38 MAPK phosphorylation was measured. L-998 inhibited LPS-induced production of TNF-α and IL-1ß and did not alter KC and MCP-1 levels. Furthermore, L-998 also significantly decreased neutrophil accumulation in lung tissues. As expected, L-998 diminished p38 MAPK phosphorylation and reduced acute lung inflammation. Inhibition of p38 MAPK phosphorylation by L-998 was also demonstrated in LPS-challenged murine C57BL/6 peritoneal macrophages in vitro, with concentration-dependent effects. L-998 suppressed LPS-induced lung inflammation, most likely by inhibition of the cytokine-p38 MAPK pathway, and we postulate that L-998 could be a clinically relevant anti-inflammatory drug candidate.
Subject(s)
Anti-Inflammatory Agents/pharmacology , Inflammation/drug therapy , Quinolines/pharmacology , Urea/pharmacology , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , Animals , Anti-Inflammatory Agents/administration & dosage , Bronchoalveolar Lavage Fluid , Disease Models, Animal , Dose-Response Relationship, Drug , In Vitro Techniques , Inflammation/pathology , Inflammation Mediators/metabolism , Lipopolysaccharides/toxicity , Lung/drug effects , Lung/pathology , Macrophages, Peritoneal/drug effects , Macrophages, Peritoneal/metabolism , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Neutrophils/drug effects , Neutrophils/metabolism , Phosphorylation/drug effects , Quinolines/administration & dosage , Urea/administration & dosageABSTRACT
We have showed that a phospholipase A(2) isolated from Lachesis muta snake venom, denoted LM-PLA(2)-I, had some biological effects. Here, we examined its effects on lymphocytes. Pre-incubation of human peripheral blood lymphocytes with LM-PLA(2)-I plus phosphatidylcholine (PC) stimulated the natural killer (NK) activity. This was accompanied by DNA binding of nuclear transcription factor kappaB and the increase in PKC activity with translocation of the enzyme from the cytoplasma into the plasma membrane. These effects were reproduced when lymphocytes were pre-incubated with commercial lysophosphatidylcholine (LPC) and abolished by stausrosporin or p-bromophenacyl bromide. Evaluation of phosphorylated PKC isoforms showed that pre-incubation with LPC activated the autophosphorylation of the PKCzeta isoform. Taken together, these results confirm that the enzymatic activity of the phospholipase A(2) present in L. muta venom is for the biological activity of the snake venom, and strongly suggest that the LPC produced may be acting as a modulator of PKC isoforms.
Subject(s)
Crotalid Venoms/chemistry , Crotalid Venoms/enzymology , Killer Cells, Natural/drug effects , Lysophosphatidylcholines/metabolism , Phospholipases A/metabolism , Protein Kinase C/metabolism , Animals , Cell Line, Tumor , Humans , Lysophosphatidylcholines/pharmacology , Phosphatidylcholines/metabolism , Phospholipases A2 , Phosphorylation , Protein Isoforms , Staurosporine/pharmacology , Viperidae/metabolismABSTRACT
This paper describes the synthesis and anti-inflammatory activity of new N-phenyl-phthalimide sulfonamides (3a-e) and the isosters N-phenyl-phthalimide amides (4a-e), designed as hybrids of thalidomide (1) and aryl sulfonamide phosphodiesterase inhibitor (2). In these series, compound 3e (LASSBio 468), having a sulfonyl-thiomorpholine moiety, showed potent inhibitory activity on LPS-induced neutrophil recruitment with ED(50)=2.5mg kg(-1), which was correlated with its inhibitory effect on TNF-alpha level.
