Erratum

In the article "Angiotensin II/Angiotensin II Receptor Blockade Affects Osteoporosis via the AT1/AT2-Mediated cAMP-Dependent PKA Pathway" [Cells Tissues Organs. 2017;204(1):25-37; https://doi.org/10.1159/000464461] by Yi Zhou et al., the authors noted there was an error in Figure 4c.Fig. 4.c Osteoclastic activity was estimated by TRAP staining. After completing osteoclast induction in the cell plate, cells were gently washed and fixed in 4% formaldehyde at room temperature for 30 s, followed by the TRAP staining procedure.An error in image naming and processing resulted in an incorrect image being placed in the fourth experimental group (AngII+ ARB1- ARB2+ group). The authors have verified the corrected image by checking laboratory records and timestamp of raw pictures. Due to the errors in labelling the first two images of each group, the authors have also replaced the blank control (AngII-; ARB1-; ARB2-) in Figure 4c.Detailed Protocol for TRAP StainingAlthough Figure 4c may visually suggest heterogeneity in staining among the groups, quantitative cell counting confirmed that the trends across groups were consistent and supported the conclusions of the article. The apparent visual differences are likely attributable to insufficient staining. The authors have outlined the contours of insufficiently stained cells with yellow dashed lines for clarity. Sample preparation was performed as follows: after completing osteoclast induction in the cell plate, the culture medium was discarded. The cell layer was gently washed with pre-warmed (37°C) PBS to prevent cell detachment. Cells were then fixed in 4% formaldehyde at room temperature for 30 s, followed by the TRAP staining procedure. Under light microscopy, TRAP-positive cells containing three or more nuclei were defined as multinucleated cells (MNCs).The corrected Figure 4c is shown here.