Fig. 2: Peritoneal Macrophages accumulate into the intestinal injury site directly via the peritoneal route regardless of CCR2 or Nr4a1.

a Luminex assays of chemokines in colon tissue samples at steady state and 24 h after thermal injury. n = 5 (control group) and 8 (injury group). b Representative images of large F4/80^hi cells accumulated in injury site at 48 h after focal intestinal injury in WT, Ccr2^RFP/RFP, and Nr4a1^−/− mouse. Scale bars, 50 μm. c The number of large F4/80^hi cells at indicated time points are quantified (n = 5/group). d Representative images and e quantification of CX3CR1⁺ cells per field of view (FOV) in lamina propria of the colon in control and 2, 7, 14 days after the intraperitoneal administration of CLL. Data were collected by imaging of CX3CR1^GFP/+ mice. n = 4 (CLL 2, 7, 14 d) and 6 (control). Scale bars, 50 μm. f Representative images of large F4/80^hi cells accumulated in intestinal injury site at 48 h post-injury. Mice were treated by PBS-L or CLL 4 days before the injury. Scale bars, 50 μm. g The number of large F4/80^hi cells are quantified. n = 3(PBS-L group) and 5(CLL group). h Schematic protocol for peritoneal cell (PC) transfer experiments (from LysM-eGFP mice to C57BL/6 mice). i Representative images and j the number of LysM-eGFP cells accumulated in C57BL/6 mice (n = 3/group). Scale bars, 100 μm. k Representative images and l quantification of LysM⁺ cells within the injured colon (6 h) of C57BL/6 mice that were transferred PCs intraperitoneally from LysM-eGFP mice with i.p. administration of PBS-L or CLL. Scale bars, 50 μm. n = 3/group. Data represent mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, NS not significant. P values were calculated with a two-tailed unpaired Student t-test (a, g, j, l) and one-way ANOVA followed by Tukey’s post hoc test (c, e). Source data are provided as a Source Data file.