Anti s6 2317

Lymphocyte separation medium, aprotinin, dimethyl sulfoxide (DMSO) and solvents for HPLC and LC/MS were purchased from Thermo Fisher Scientific (Ottawa, Ontario, Canada). Dextran, adenosine deaminase, leupeptin and potassium phosphate were obtained from Sigma-Aldrich Canada (Oakville, Ontario, Canada). HBSS was purchased from Wisent Bioproducts (St-Bruno, Quebec, Canada). 19-OH-prostaglandin (PG) B₂, PGB₂, PGB₂-D₄ and 17-octadecynoic acid (17-ODYA) were purchased from Cayman Chemicals (Ann Arbor, Michigan, USA). PF-4708671 was obtained from Abcam (Cambridge, Massachusetts, USA) and LY2584702 from Selleckchem (Houston, Texas, USA). Thapsigargin was obtained from Tocris Bioscience (Ellisville. Missouri, USA). LTB₄ was a generous gift from Dr Louis Flamand (Université Laval, Québec City, Canada). Recombinant CYP4F3A and the NADPH regenerating system were purchased from Corning (Corning, New York, USA). Protease and phosphatase inhibitor cocktail tablets were purchased from Roche (Laval, Quebec, Canada). Primary (anti-phospho-S6 #2211 and anti-S6 #2317) and secondary antibodies were obtained from Cell Signaling (Danvers, Massachusetts, USA). The enhanced chemiluminescent (ECL) substrate was obtained from Millipore Canada Ltd (Toronto, Ontario, Canada).

Pre-warmed neutrophil suspensions (37°C, 5 million cells/ml in HBSS containing 1.6 mM CaCl₂) were stimulated with 100 nM of thapsigargin or N-Formylmethionine-leucyl-phenylalanine (fMLP) for 5 minutes. PF-4708671, LY2584702 or vehicle were added 5 minutes before stimulation. Incubations were stopped using 1 volume of cold (4°C) incubation buffer. The suspensions were centrifuged (350 x g, 5 min, 4°C) and then lysed in a cold (4°C) hypotonic buffer (10 mM Tris-HCl, 10 mM NaCl, 3 mM MgCl2, 1 mM EDTA, pH 7.4) containing 0.1% NP-40, protease inhibitors (10 μg/ml aprotinin, 10 μg/ml leupetin, 1 mM PMSF, protease inhibitor cocktail tablets), 2 mM diisopropyl fluorophosphate (DFP) and phosSTOP. Cells were vortexed for 15 seconds, then immediately solubilized in electrophoresis sample buffer (62.5 mM Tris-HCl, pH 6.8, 10% glycerol, 0.01% bromophenol blue, 5% β-mercaptoethanol, 2% SDS) and boiled for 10 minutes. Proteins were loaded on a 12% polyacrylamide gel for electrophoresis, and transferred onto a PVDF membrane. Membranes were blocked using TBS/Tween buffer containing 5% w/v skim milk and incubated overnight at 4°C with primary antibodies (anti-phospho-S6 #2211 and anti-S6 #2317, Cell Signaling) in TBS/Tween containing 5% skim milk. HRP-linked secondary antibodies and ECL substrate were used for detection.