Figure 6

Knockout of TRPM2 or inhibition of lysosomal degradation reduced starvation-induced cell death. (A, B) Representative western blot images (A) and data summary (B) showing starvation-induced caspase-3 activation in mASMCs. 24 h starvation decreased the levels of pro-caspase-3 in mASMCs of WT mice, but the effect was absent in mASMCs of TRPM2 KO mice. (C–E) Representative TUNEL images (C) and data summary (D, E) showing starvation (24 h)-induced cell death of mASMCs. The cells from WT mice showed more cell death compared to the cells from TRPM2 KO mice (D, E). Inhibition of autophagy by bafilomycin A1 reduced the starvation-induced cell death in both WT and TRPM2 KO cells (D). The degradation-related cell death number was also more in cells from WT mice than those from TRPM2 KO mice (E). The green signals in C indicated TUNEL-positive apoptotic cells, while blue dots were DAPI counterstain for nuclei. Values are mean ± SEM (n = 3–4, *P < 0.05, **P < 0.01, ***P < 0.001, ns = not significant). One-way ANOVA was used for statistical test.