Figure 4

Itk expression is modulated by dexamethasone treatment in thymocytes and splenocytes in vivo. The level of Itk mRNA was evaluated in thymocytes (left panels) and splenocytes (right panels) isolated from mice treated with 5 mg/kg (empty symbol) or 25 mg/kg (black symbol) dexamethasone (DEX), or saline solution (S.S., asterisk). The animals were sacrificed 3 or 6 h after treatment. Changes in mRNA level were evaluated by RNA protection assay and evaluated as shown in Figure 2. Fold modulation is represented as the mean (±SD) of three independent experiments, with each experiment performed on cells pooled from three animals. The data are graphed on a logarithmic scale (base 2). *P < 0.05, **P < 0.01, and ***P < 0.001, according to Student’s t-test comparing the levels of Itk mRNA in cells from treated animals to that in cells from untreated animals (A) or from saline-treated animals (B). (C) Levels of Itk protein were evaluated in thymocytes from mice treated for 8 h with 5 mg/kg dexamethasone (DEX) or saline solution (S.S.). The left panel shows one representative experiment (n = 4). After densitometric analysis, the Itk/β-tubulin ratio (middle panel) and fold modulation (right panel) were calculated. ***P < 0.001, according to Student’s t-test comparing the level of Itk protein in thymocytes from DEX-treated animals to that in thymocytes from untreated and saline-treated animals.