Figure 6
From: A ligand-receptor pair that triggers a non-apoptotic form of programmed cell death
Retention of phosphatidylserine asymmetry (lack of phosphatidylserine ‘flipping’) and absence of DNA fragmentation in SP-induced cell death. Cells transfected with NK1R in the absence (A–C) or presence of 10 μM SP for 24 h (D,E) were stained with FITC-Annexin-V (B,E), then fixed and immunostained to detect NK1R (C,F), demonstrating that the cells expressing NK1R were negative for FITC-Annexin-V staining. As a control for apoptosis, cells were transfected with Bax (G,H) and stained with FITC-Annexin-V (H). Scale bar, 50 μm. Note that the few cells that are Annexin-V positive in (E) are not those expressing NK1R (compare F). (I) TUNEL staining of 293T cells transfected with NK1R and treated for 24 h with 10 μM SP. (J) Propidium iodide (PI) staining of the same field as in I, to show the total number of cells. (K) TUNEL staining of cells transfected with Bax as a positive control for apoptosis. (L) Propidium iodide staining of the same field as in K