Erratum to: Mitochondrial control of cell death induced by hyperosmotic stress

Erratum to: Apoptosis (2007) 12:3–18 DOI 10.1007/s10495-006-0328-x

Errors were inadvertently included in Fig. 6b of the article mentioned above. In particular, the immunoblots depicting the levels of Bcl-X_L and Mcl-1, which were originally intended to constitute loading controls for the assessment of Bak and Bax depletion, respectively, were both improperly associated with to Bak- and Bax-related immunoblots, due to pasting errors at figure composition. The amended version of the figure is reported below. Neither quantitative determinations nor the conclusions of this article are altered. The authors apologize for these errors.

Fig. 6

Involvement of the Bcl-2 protein family in hyperosmotic stress-induced death of A549 cells. (a) A549 cells were treated with the indicated dose of sorbitol for 6 h, followed by the cytofluorometric assessment of mitochondrial membrane potential (DiOC₆(3) staining) and viability (PI staining). White columns illustrate the percentage of cells with a low mitochondrial membrane potential but still viable (DiOC₆(3)^low). Black columns indicate the percentage of cells with disrupted plasma membrane (PI⁺). Data are mean of duplicate experiments ± SEM. (b, c) A549 cells were transfected with empty liposomes (Mock) or with siRNAs targeting Bax, Bak, Bcl-2, Bcl-X_L, p53, the voltage-dependent anion channel 1 (VDAC1) or an irrelevant “unrelated” control (UNR). (b) To check for the effects of siRNAs, total proteins were purified from transfected A549 cells at different time points (12, 24 or 48 h), separated according to molecular weight on mono-dimensional SDS-PAGE, and finally analyzed by immunoblotting with the indicated antibodies. Antibodies specific for Mcl-1 and Bcl-X_L or for GAPDH were employed as loading controls. (c) A549 cells transfected for 48 h with the indicated siRNAs were treated with 600 mM sorbitol for additional 6 h, then analyzed at FACS for mitochondrial membrane potential (DiOC₆(3) staining) and viability (PI staining). White columns depict the percentage of cells that have dissipated the mitochondrial membrane potential but are still viable (DiOC₆(3)^low). The percentage of cells with disrupted plasma membrane (PI⁺) is illustrated by black columns. Data are mean of duplicate experiments ± SEM. Dashed lines indicate the range of statistical insignificance from control cells (p > 0.05, ± 3 SEM). For additional details please see also “Materials and methods”