Fig. 4.

The anion transport mutant exerts a dominant negative effect on efferocytosis. (A, B) LR73 cells expressing the proton leak mutations of Ucp2, Ucp2^D28N and Ucp2^D212N, were incubated with apoptotic thymocytes (A) or 2 μm carboxylate-modified beads (B) for 2 h and analyzed by flow cytometry. (C, D) LR73 cells were transfected with the indicated plasmids and incubated with apoptotic thymocytes (C) or 2 μm carboxylate-modified beads (D) for 2 h. Phagocytes ingesting apoptotic thymocytes (C) or the beads (D) were evaluated by flow cytometry. (E) The Ucp2 and mutated Ucp2 proteins were expressed in LR73 cells and then the cells were incubated with TAMRA-stained apoptotic thymocytes for 1 h to 5 h. The mean fluorescence intensity (MFI) of TAMRA of the cells ingesting apoptotic cells was measured by flow cytometry. NS, not significant; ^*P < 0.05, ^**P < 0.01, ^***P < 0.001.