PMNs were resuspended in Hank’s balanced salt solution (HBSS) without divalent cations (HBSS-) at 5 × 105 PMNs/ml and were incubated with 5 μM calcein-AM (Invitrogen) for 30 min at 37°C [46]. PMNs were washed three times with HBSS- after which their purity was > 95% and viability 98% by trypan blue dye exclusion. PMNs were resuspended in HBSS with divalent cations (HBSS+) immediately prior to use. Assay for TEM of PMNs TEM of PMNs was assayed as previously described [46]. Briefly, gelatin-impregnated polycarbonate filters (13 mm diameter, 3 μm pore size; Nucleopore, Pleasanton, CA) were mounted in polysterene

chemotactic chambers (ADAPS, Dedham, MA), and sterilized overnight with UV irradiation. These chambers, which serve as the upper compartment for each assay chamber, were inserted into the wells of 24-well plates, each well serving as

the lower compartment of the assay chamber and containing 1.5 mL of medium. Each upper compartment Doramapimod concentration was seeded with 2.0 × 105 HMVEC-Ls/chamber in 0.5 mL and cultured GSK690693 to confluence (48 h, 37°C, 5% CO2). The EC monolayers cultured on filter supports were treated for 4 h with either ET at increasing concentrations or medium alone. In other experiments, the EC monolayers were treated for either 0.5 h or 4 h with either FSK (10 μM), IBMX (1 mM), or medium alone. These same chambers were then inserted into wells containing IL-8 (10 ng/mL) or medium alone. Calcein-AM-labeled PMNs (5 × 105 cells/well) were introduced into the upper compartments of assay chambers, incubated for 2 h at 37°C, after which time the contents of each lower compartment were fluorometrically assayed in a Thermo Scientific Fluoroskan Ascent fluorometer

(excitation 485 nm, emission 530 nm). Etoposide in vitro The fluorescence of 5 × 105 calcein-AM labeled PMNs was used to generate total fluorescence. % TEM was expressed as fluorescence signal in the lower chamber/total fluorescence signal in the upper compartment × 100%. Chemotaxis of PMNs Chemotaxis of PMNs was assayed as described [47]. Briefly, gelatin-impregnated polycarbonate filters were mounted in chemotactic chambers, and the chambers inserted into the wells of 24-well plates containing IL-8 (10 ng/mL) or medium alone, as described above. Calcein-AM-labeled PMNs (5 × 105 cells/well) were suspended in either medium alone learn more versus medium containing increasing concentrations of ET before being placed into the upper compartment of assay chambers and incubated for 2 h at 37°C. The lower compartment was then sampled and fluorometrically assayed. The fluorescence of 5 × 105 calcein-AM-labeled PMNs was used to generate total fluorescence. % chemotaxis was then expressed as fluorescence signal in the lower chamber/total fluorescence signal in the upper compartment × 100%. In other experiments, unlabeled PMNs were introduced into the upper compartment of a modified Boyden chemotaxis chamber (Neuroprobe Inc.