Fig. 2

BM-MSC apoptosis induced by IFNγ and TNFα is mediated by NO. a Wild-type, Fas^−/−, and iNOS^−/− BM-MSCs were treated with IFNγ plus TNFα for 24 h or for the indicated time. The levels of iNOS expression were quantified by real-time PCR. b Wild-type and iNOS^−/− BM-MSCs were treated with IFNγ/TNFα (10 ng/ml each) for 48 h. Apoptotic cells were analyzed using flow cytometry. The percentage of Annexin V-positive cells relative to untreated controls is indicated in a bar chart. c Wild-type BM-MSCs were treated with IFNγ/TNFα (10 ng/ml each) in the absence or presence (1 h pre-incubation) of L-NMMA (1 mM) for 48 h. Apoptotic cells were analyzed using flow cytometry. The percentage of Annexin V-positive cells relative to untreated controls is indicated in a bar chart. d Percentage of iNOS^−/− BM-MSC survival after treatment with various concentrations of different cytokines. e Wild-type MSCs were treated with SNAP (0.5 mM) for 48 h. Apoptotic cells were analyzed using flow cytometry. The percentage of Annexin V-positive cells relative to untreated controls is indicated in a bar chart. f iNOS^−/− BM-MSCs were treated with the indicated conditions for 48 h. Apoptotic cells were analyzed using flow cytometry. The percentage of Annexin V-positive cells relative to untreated controls is indicated in a bar chart. g Wild-type BM-MSCs were treated with SNAP; pro-apoptotic and anti-apoptotic transcripts were quantified by real-time PCR. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001