Quantifying the reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide

Quantifying the reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, Sigma-Aldrich) to formazan, a reaction catalyzed by cellular reductases and dependent on the availability of reducing equivalents in the cell [47]. After synchronization (serum order 58-49-1 deprivation for 48 h), THP-1 cells were plated at 16105 cells/well in 96-well plates. To compare effects in monocytic THP1 cells versus THP-1 macrophages, PMA (20 ng/ml) was added to the latter cultures 24 h prior to experimentation. For undifferentiated THP-1, cells were plated onto poly-D-lysine (100 mg/ml, Sigma-Aldrich)-coated wells immediately prior to initiating the experiment. MTT was added to the wells at 500 mg/ml final concentration and cells were incubated at 37uC under the culture conditions indicated in Figure 2 for 3 h. The supernatant 23115181 was carefully aspirated and 5 triton X-100 (Fisher Scientific) in phosphate-buffered saline (PBS, 1 mM KH2PO4, 2.97 mM Na2HPO4.7H2O, and 155 mM NaCl, pH 7.4) was added to each well. The cells were then incubated at 37uC for 2 h prior to determining the optical density (OD) at 562 nm using a TECAN spectrophotometer (Spectra FLUOR Plus, Tecan Systems, Inc., San Jose, CA). Results were normalized against protein concentration as Indolactam V site determined using the BCATM Protein Assay Kit (Thermo Scientific, Rockford, IL, USA).upon lysosomal uptake and subsequent acidification. Cells were synchronized for 48 h, plated at a density of 105 cells/well in a 96well plate and differentiated by PMA treatment for 48 h without 2-ME and FBS. Negative controls were incubated with 2 mM cytochalasin D (Sigma-Aldrich) for 1 h before the addition of the E. coli BioParticlesH to inhibit phagocytosis. For some experiments, THP-1 were PMA-differentiated at low or high oxygen tension for 24 h and then switched to high and low oxygen tension, respectively, 1 h before the addition of the BioParticlesH. Cells were incubated with BioParticlesH for 90 minutes, washed and fluorescence was quantified using the Molecular Devices SpectraMax plate reader (Molecular Device, Sunnyvale, CA, USA) with the excitation wavelength set at 550 nm and the emission wavelength detection set at 600 nm. Results were normalized against protein concentration as determined using the BCA protein assay.NF-kB ActivationTHP-1 XBlue cells grown without 2-ME and FBS were synchronized by serum deprivation for 48 h followed by PMAdifferentiation for 48 h in 96-well plates at 16105 cells/well under 5 or 18 oxygen. Differentiated THP-1 XBlue cells were washed twice with PBS and stimulated by 1 mg/ml of lipopolysaccharide (LPS) derived from gram-negative bacteria (clone 055:B5, Sigma). NF-kB activation was determined by quantifying the secretion of embryonic alkaline phosphatase (SEAP), which was detected by Quanti-Blue reagent (Invitrogen) using a Synergy H1 microplate reader (BioTek Instruments, Inc., Winooski, VT). To determine whether oxidative stress influenced LPS-induced NF-kB activation, differentiated THP-1 XBlue cells were incubated for 4 h with diphenylene iodinium (DPI, Sigma) at 0.3?10 mM or nordihydroguaiaretic (NGA, Sigma) at 3?00 mM) before LPS stimulation.Quantifying the Rate of THP-1 Macrophage DifferentiationUndifferentiated THP-1 cells were synchronized by serum deprivation for 48 h prior to re-plating at 16105 cells in 96-well plates in media containing 20 ng/ml PMA. Cells were then cultured at 37uC in 18 or 5 O2 with or without 2-ME and/or FBS. After 3 or 24 h of PMA stim.Quantifying the reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, Sigma-Aldrich) to formazan, a reaction catalyzed by cellular reductases and dependent on the availability of reducing equivalents in the cell [47]. After synchronization (serum deprivation for 48 h), THP-1 cells were plated at 16105 cells/well in 96-well plates. To compare effects in monocytic THP1 cells versus THP-1 macrophages, PMA (20 ng/ml) was added to the latter cultures 24 h prior to experimentation. For undifferentiated THP-1, cells were plated onto poly-D-lysine (100 mg/ml, Sigma-Aldrich)-coated wells immediately prior to initiating the experiment. MTT was added to the wells at 500 mg/ml final concentration and cells were incubated at 37uC under the culture conditions indicated in Figure 2 for 3 h. The supernatant 23115181 was carefully aspirated and 5 triton X-100 (Fisher Scientific) in phosphate-buffered saline (PBS, 1 mM KH2PO4, 2.97 mM Na2HPO4.7H2O, and 155 mM NaCl, pH 7.4) was added to each well. The cells were then incubated at 37uC for 2 h prior to determining the optical density (OD) at 562 nm using a TECAN spectrophotometer (Spectra FLUOR Plus, Tecan Systems, Inc., San Jose, CA). Results were normalized against protein concentration as determined using the BCATM Protein Assay Kit (Thermo Scientific, Rockford, IL, USA).upon lysosomal uptake and subsequent acidification. Cells were synchronized for 48 h, plated at a density of 105 cells/well in a 96well plate and differentiated by PMA treatment for 48 h without 2-ME and FBS. Negative controls were incubated with 2 mM cytochalasin D (Sigma-Aldrich) for 1 h before the addition of the E. coli BioParticlesH to inhibit phagocytosis. For some experiments, THP-1 were PMA-differentiated at low or high oxygen tension for 24 h and then switched to high and low oxygen tension, respectively, 1 h before the addition of the BioParticlesH. Cells were incubated with BioParticlesH for 90 minutes, washed and fluorescence was quantified using the Molecular Devices SpectraMax plate reader (Molecular Device, Sunnyvale, CA, USA) with the excitation wavelength set at 550 nm and the emission wavelength detection set at 600 nm. Results were normalized against protein concentration as determined using the BCA protein assay.NF-kB ActivationTHP-1 XBlue cells grown without 2-ME and FBS were synchronized by serum deprivation for 48 h followed by PMAdifferentiation for 48 h in 96-well plates at 16105 cells/well under 5 or 18 oxygen. Differentiated THP-1 XBlue cells were washed twice with PBS and stimulated by 1 mg/ml of lipopolysaccharide (LPS) derived from gram-negative bacteria (clone 055:B5, Sigma). NF-kB activation was determined by quantifying the secretion of embryonic alkaline phosphatase (SEAP), which was detected by Quanti-Blue reagent (Invitrogen) using a Synergy H1 microplate reader (BioTek Instruments, Inc., Winooski, VT). To determine whether oxidative stress influenced LPS-induced NF-kB activation, differentiated THP-1 XBlue cells were incubated for 4 h with diphenylene iodinium (DPI, Sigma) at 0.3?10 mM or nordihydroguaiaretic (NGA, Sigma) at 3?00 mM) before LPS stimulation.Quantifying the Rate of THP-1 Macrophage DifferentiationUndifferentiated THP-1 cells were synchronized by serum deprivation for 48 h prior to re-plating at 16105 cells in 96-well plates in media containing 20 ng/ml PMA. Cells were then cultured at 37uC in 18 or 5 O2 with or without 2-ME and/or FBS. After 3 or 24 h of PMA stim.