PDGF Suppresses Oxidative Stress Induced Ca²⁺ Overload and Calpain Activation in Neurons

Figure 1

Effects of PDGF-AA and PDGF-BB on the H₂O₂-induced increase in [Ca²⁺]_𝑖. [Ca²⁺]_𝑖 was determined using Fura-2-AM fluorescent dye. (a) Pseudocolor images representing the relative [Ca²⁺]_𝑖 indicated by the fluorescence ratio between 340 and 380 nm (F340/380) in individual cortical neurons 15 and 30 min after the H₂O₂ treatment. Following a 24 h preincubation with 50 ng/mL PDGF-BB, neurons were loaded with Fura-2-AM and exposed to different concentrations of H₂O₂ (5, 10, and 20 μM). The inserted bar indicates the relationship between colors and fluorescent intensity ratios at 340 and 380 nm. (b) Histogram analyses of the mean F340/380 of (a). Three pictures were taken from each well, and the means of the F340/380 of each neuron were calculated. Data are expressed as means ± SEM derived from three different sets of experiments. (c) To compare the effects of PDGF-AA and PDGF-BB on [Ca²⁺]_𝑖 overload induced by H₂O₂, cells were pretreated with 50 ng/mL PDGF-AA or PDGF-BB for 24 h followed by exposure to 10 μM H₂O₂ for 15 and 30 min. (d) Histogram analysis of (c). Data are expressed as means ± SEM of three independent experiments. ^a1𝑃<0.01 and ^a2𝑃<0.05 versus the untreated control; ^b𝑃<0.01 versus the same H₂O₂ exposure without the PDGF pretreatment; ^c1𝑃<0.01 and ^c2𝑃<0.05 versus the same H₂O₂ exposure with the PDGF-AA pretreatment.

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