Fig. 7
Macrophages are required for red blood cell (RBC) transfusion-associated necrotizing enterocolitis (NEC). a Representative scatter plots from naive control, anemic-transfused, and corresponding clodronate-treated groups show depletion of F4/80 (hi) macrophages in clodronate-treated naive control, and of both F4/80 (hi) and F4/80 (mid) populations in clodronate-treated anemic-transfused mice. N = 8 mice per group. b Kaplan–Meier curves show survival without intestinal injury in anemic-transfused vs. clodronate-treated anemic-transfused pups; N = 8 mice per group, Mantel–Cox log-rank test, **P < 0.01. c Top: Representative photographs show intestinal injury in an anemic-transfused pup (arrows) and the absence of injury in a clodronate-treated anemic-transfused pup; bottom: d Scatter plots show severity of bowel injury in anemic-transfused vs. clodronate-treated anemic-transfused mice. N = 8 mice per group; 2 mice in the clodronate-treated group died within 1 h of presumed procedure-related causes and were excluded; Mann–Whitney U test, *P < 0.05. d Schematic (left) of the bacterial artificial chromosome (BAC) encoding a diphtheria toxin receptor (DTR)-mCherry fusion protein preceded by a loxP-flanked transcriptional Stop element, driven by the CD115 promoter in C57BL/6-Tg(Csf1r-HBEGF/mCherry)1Mnz/J mice; IRES = internal ribosome entry site. Right: representative scatter plots from anemic CSF1R-DTR/mCherry × Lyz2 (lysozyme 2)-cre mice show depletion of F4/80 (mid) CD115 (+) Ly6Chi macrophages following DT administration. e Kaplan–Meier curves below show survival without intestinal injury of mock- and DT-treated anemic-transfused mice; N = 6 mock-treated, 4 DT-treated anemic-transfused mice, Mantel–Cox log-rank test, **P < 0.01. f Top: Representative photographs show intestinal injury in anemic-transfused (arrows) vs. the absence of injury in a DT-treated, anemic-transfused pup. Bottom: Scatter plots show severity of bowel injury in the mock- vs. DT-treated anemic-transfused CSF1R-DTR/mCherry × Lyz2-cre mice. N = 6 mock-treated, 4 DT-treated anemic-transfused mice; Mann–Whitney U test, **P < 0.01. All scatter plots summarize the data as means ± standard error of the mean
