Figure 3
α 1 -antitrypsin (A1AT) reduces intracellular calcium levels and calpain activity in microglial cells. To detect intracellular calcium levels, BV-2 microglial cells were loaded with Fluo-4 and baseline calcium levels for each well were measured and subtracted from the values. Cells were treated with 0.1 μg/ml lipopolysaccharide (LPS) and/or 2 and 4 mg/ml A1AT, and the course of intracellular calcium was measured over 200 minutes. RFU (relative fluorescence units) were normalized to time point zero. A shows the course of the values for LPS and LPS + 4 mg/ml A1AT co-treated cells. One representative experiment out of three is shown. B shows the mean values and standard deviations of the mean of the RFU of six wells after 100 minutes for LPS and/or A1AT-treated cells (***P value ≤ 0.001). C. Calpain activity was detected 24 hours after A1AT treatment with different concentrations of A1AT by using a calpain activity assay. Calpain activity of untreated cells was referred to as 100% activity. Means and standard deviations of the mean of three independent experiments are shown (*P value ≤ 0.05, **P value ≤ 0.01).