PNU-120596

SH-EP1 human epithelial cells expressing a variant of theα7 nAChR (α7^*) are grown in minimal essential medium (MEM) containing nonessential amino acids supplemented with 10% fetal bovine serum, L-glutamine, 100 U/ml penicillin/streptomycin, 250 ng/mL fungizone, 400 μg/mL hygromycin B, and 800 μg/mL geneticin. α7^* is a variant of the human α7 nAChR, with two point mutations in the first transmembrane domain (T230P and C241S) that allow for high functional expression in SH-EP1 cells [Groppi VE, Wolfe ML, Berkenpas MB (2003) U.S. Patent 6,693,172 B1]. Cells are grown in a 37 °C incubator with 6% CO₂. Cells are trypsinized and plated in 96-well plates with dark side walls and clear bottoms at a density of 2 × 10⁴ cells/well 2 days before analysis. Cells are loaded with a mixture of Calcium reen-1AM in anhydrous dimethylsulfoxide and 20% pluronic F-127. This reagent is added directly to the growth medium of each well to achieve a final concentration of 2 μM Calcium Green-1 AM. Cells are then incubated in the dye for 1 hour at 37 °C and then washed four times with Mark's modified Earle's balanced salt solution (MMEBSS) composed of the following (inmM): 4 CaCl₂, 0.8 MgSO₄, 20 NaCl, 5.3 KCl, 5.6 D-glucose, 20 Tris-HEPES, and 120 N-methyl-D-glucamine, pH 7.4. After the fourth cycle, the cells are allowed to incubate at 37 °C for at least 10 minutes. The final volume of MMEBSS in each well is 100 μL and atropine is added to all wells for a final concentration of 1 μM. A fluorometric imaging plate reader (FLIPR; Molecular Devices, Union City, CA) is set up to excite Calcium Green at 488 nm using 500 mW of power and reading fluorescence emission of >525 nm. A 0.5 seconds exposure is used to illuminate each well. Fluorescence is detected using an F-stop set of either 2.0 or 1.2. After 30 seconds of baseline recording, test compounds are added to each well of a 96-well plate in 50 μL of a 3 × stock. In each experiment, four wells are used as vehicle (0.2% DMSO) controls.

SH-SY5Y-α7 cells

3-10 μM

24 hours

SH-SY5Y-α7 cells are plated on 96-well plates at a density of 15,000 cells per well (100 μL of 1.5 × 10⁵ cells per mL) in complete growth medium and placed into a 37 °C incubator for 20 to 24 hours. Complete growth medium then is replaced with experimental medium alone ("PNU-120596 free") or containing appropriate concentrations of PNU-120596 and returns to the 37 °C ncubator for 20 to 24 hours. The medium is then replaced with fresh experimental medium and 20 μL per well MTS solution and returned to the 37 °C incubator for 3 hours, after which the plate is read on a microplate spectrophotometer at an absorbance of 490 nm. For all data analysis, data are normalized to untreated compound-free wells (100% cell viability) and a background absorbance taken from wells containing experimental medium and MTS solution.

male Sprague Dawley rats (weighing 250–300 g)

1 mg/kg

PNU-120596 is intravenously administrated 5 minutes before auditory gating measurements.