Fig. 7: Pancreatic macrophages release a panel of growth factors regulating organ fibrosis.

a Bone marrow derived macrophages were isolated from C57Bl/6 mice and co-incubated with CCK-stimulated acini for 6 h. Total RNA was isolated from BMDMs and transcriptome profiling was performed using Affymetrix GeneChip Mouse Gene 2.0 ST Arrays. Expression changes of genes encoding growth factors are visualized by a heat map. The gene-specific transcript levels of Ngf, Inhba, Fst, Fgf1, Ereg, and Areg encoding Nerve growth factor, inhibin A subunit β, follistatin, fibroblast growth factor 1, epiregulin, and amphiregulin, respectively, were significantly increased in BMDMs after co-incubation with acini. b Growth factor gene expression was also investigated in pancreatic tissue from DEREG mice +/− DT by RT-qPCR. Expression of Inhba encoding Inhibin βA was significantly increased in DT-treated mice (p = 0.0242, PBS n = 10/DT n = 7) whereas transcript levels of Inha encoding inhibin α were not affected (PBS n = 6/DT n = 6). Expression of Fst encoding follistatin was significantly decreased in DT-treated mice (p = 0.0049, PBS n = 7/DT n = 6). Transcript levels as determined by RT-qPCR were normalized using Rn5s as internal calibrator gene and were related to the corresponding mRNA amounts in control mice. c Immunofluorescence labeling of inhibin βA and CD206 demonstrates co-localisation. c, d Gene expression of growth factors FGF1 (p = 0.0173, PBS n = 7/DT n = 6) and TGFB (p = 0.0113, PBS n = 8/DT n = 6) was also upregulated in the pancreas of DT-treated mice and an higher expression of collagen 1 was shown by immunofluorescence labeling and RT-qPCR (two-tailed Mann-Whitney test p = 0.0053, PBS n = 13/DT n = 8). e Additional labeling of the FGF-receptor on α-SMA⁺ PSCs demonstrates increased fibrogenesis in DT-treated mice, scale bars represent 20 µm. Significantly differential mRNA levels as detected by microarray-based transcriptome analysis were defined using the following criteria: one-way ANOVA with Benjamini and Hochberg false discovery rate (p ≤ .05), signal correction statistics (Ratio Builder software; p ≤ .05), and an expression value ratio between the different conditions ≥1.5-fold (n = 3). All data were presented as means ± SEM, statistically significant differences were tested by unpaired two-tailed students t-test for independent samples, except the collagen 1 gene expression was tested by two-tailed Mann-Whitney test for nonparametric samples, significance levels of p < 0.05 are marked by an asterisk (b, d). Source data are provided as a Source Data file.