Figure 3.

ERK5 has a key role in induction by apoptotic cell (AC) feeding of efferocytosis-related genes in cultured bone marrow–derived macrophages. A through C, Incubation of bone marrow–derived macrophages with ACs for 16 hours increased mRNA expression of opsonins (n=5; A) and proteins involved in “eat-me” (n=4; B) and “find-me” (n=4; C) signals in an ERK5-dependent manner. Downregulation of CD47 (don’t-eat-me signal) expression by AC feeding did not occur in ERK5-MKO macrophages. Data are mean±SD. NLC vs nontransgenic littermate control (NLC)+ACs, *P<0.05, **P<0.01; NLC+ACs vs ERK5-MKO+ACs, #P<0.05, ##P<0.01. D, Relative mRNA levels of inflammatory (left) and anti-inflammatory (right) genes in bone marrow–derived macrophages isolated from NLC or ERK5-MKO mice were assessed by quantitative reverse transcription polymerase chain reaction. Data are mean±SD (n=4); *P<0.05, **P<0.01. E, Protein expressions of inflammatory (inducible nitric oxide synthase [iNOS] and monocyte chemotactic protein-1 [MCP-1]) and anti-inflammatory (arginine [Arg]-1 and interleukin-10 [IL-10]) proteins in bone marrow–derived macrophages isolated from NLC or ERK5-MKO mice were assessed by Western blotting. Comparison between 2 independent groups was subjected to Wilcoxon rank sum test. A, B, and C, Subjected to multiple group analysis with Kruskal-Wallis test followed by Dunn post hoc analysis.