Figure 1.

Characterization of mesenchymal stem cells (MSCs) isolated from male rat bone marrow and time course of Hsp20 expression in response to H₂O₂ treatment (200 μM). (A): Cultured P3 MSCs were immunostained with primary antibodies as indicated. Alexa Fluor 594 goat anti-rabbit or mouse IgG was used as a secondary antibody and also negative controls. Images of phase contrast are at original magnification, ×100; the immunocytochemistry images are at original magnification, ×400. (B): At the indicated intervals, MSCs treated with H₂O₂ were lysed to assess Hsp20 expression by Western blot analysis. Panel (C) shows the quantitative results from the Western blots. Similar results were observed in three additional, independent experiments. β-Actin was used as internal control. Abbreviations: Hsp, heat-shock protein; P1, passage 1; P3, passage 3.