Ablation of the Pro-Apoptotic Protein Bax Protects Mice from Glucocorticoid-Induced Bone Growth Impairment
Figure 4
Conformational changes in Bax and translocation to mitochondria.
(A) Immunocytochemistry of HCS cells in proliferation phase, treated or untreated with Dexa (25 µM) for 72 hrs. Cells were analyzed for conformational changes in Bax using a specific antibody that only detects conformationally altered Bax. Chondrocytes were labeled with Bax antibody (red) and MitoTracker (green). Bax was mainly found in the mitochondria of Dexa-treated cells, as shown by the yellow-orange staining that is due to the merged red and green fluorescence. (B) Cultured fetal rat metatarsal bones treated with Dexa stained for DAPI (blue) and conformationally altered Bax (Conf- Bax; red). (C) Growth plate sections (tibia) of 7-week-old rats treated with Dexa (5 mg/kg/day) for 7 days. Immunohistochemistry was performed by triple-fluorescent labeling for conformationally changed Bax (Conf- Bax; red), HSP60 antibody (green), and DAPI (nuclei; blue). Conformationally changed Bax was mainly found in the chondrocyte mitochondria of those animals treated with Dexa, as shown by the yellow-orange staining that is due to the merging of red and green fluorescence.