Effect of 5-lipoxygenase inhibitor MK591 on early molecular and signaling events induced by staphylococcal enterotoxin B in human peripheral blood mononuclear cells.
Staphylococcal enterotoxin B (SEB) has been the focus of a number of studies due to its ability to promote septic shock and a massive impact on the human immune system. Even though symptoms and pathology associated with SEB is well known, early molecular events that lead to lethality are still poorly understood. Our approach was to utilize SEB induced human peripheral blood mononuclear cells (PBMCs) as a prototype module to further investigate the complexity of signaling cascades that may ultimately lead to lethal shock. Our study revealed the activation of multiple divergent intracellular pathways within minutes of SEB induction including components that interconnect investigated pathways. A series of performed inhibitor studies identified a specific inhibitor of 5-LO (MK591), which has the ability to block JNK, MAPK, p38kinase and 5-LO signaling-cascades and drastically reducing the activity of pro-inflammatory cytokine TNF-alpha. Further evaluation of MK591 utilizing cell proliferation assays in PBMCs, human proximal tubule cells and in vivo studies (monkey) showed a decrease in cell proliferation. The inhibitory effect of MK591 was reconfirmed at a genetic level through the utilization of a set of SEB specific genes. Signaling activities, inhibitor studies, cellular analysis and gene expression analysis in unison illustrated the significance of pathway interconnectors such as 5-LO as well as inhibiting such inter-connectors (using MK591) in SEB induced human PBMCs.
Mendis
Chanaka
C
Department of Chemistry and Engineering Physics, University of Wisconsin-Platteville, 1 University Plaza, Platteville, WI, USA. mendisc@uwplatt.edu
Campbell
Katherine
K
Das
Rina
R
Yang
David
D
Jett
Marti
M
D000328:Adult; D000818:Animals; D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D004768:Enterotoxins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D000882:Haplorhini; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000187:drug effects; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology*; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D011804:Quinolines / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D004768:Enterotoxins; D007211:Indoles; D016859:Lipoxygenase Inhibitors; D011804:Quinolines; D014409:Tumor Necrosis Factor-alpha; C078266:MK 0591; C031818:enterotoxin B, staphylococcal; D001094:Arachidonate 5-Lipoxygenase; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases