Figure 5. Suppression of TGFβ-induced changes in αSMA and Pax6 expression by catalase. Explants were cultured for two days with catalase alone at a concentration of 300 units/ml (A-C) or with 75 pg/ml TGFβ2 in the absence (D-F) or presence (G-I) of catalase and then fixed as whole mounts and processed for immunolocalization of Pax6 (red; B,E,H) and αSMA (green; C,F,I) by a double labeling technique. Nuclei were counterstained using Hoechst dye (blue; A,D,G). Images of the same explant region are shown in each row. Explants cultured with catalase alone were indistinguishable from the controls in that they exhibited strong nuclear expression of the lens epithelial cell marker, Pax6 (B), and lacked reactivity for the transdifferentiation marker, αSMA (C). Explants cultured with TGFβ lost reactivity for Pax6 (E) and contained many αSMA-positive cells (F). Catalase protected against TGFβ-induced loss of Pax6 expression (H) and and strongly suppressed the induction of αSMA by TGFβ (I). The scale bar represents 60 μm (A-I). Cat, catalase.