Figure 2.
IGF-1 growth factor expression increases after irradiation-induced intestinal damage. Duodenal tissue from UNIRR and 12-Gy–treated mice at the damage (48 HPI), regeneration (4 DPI), and recovery (6 DPI) phases was isolated and tested for expression of 84 growth factors by RT2 Profiler PCR array analysis. (A) Heat map of growth factor expression after irradiation injury, with red representing higher and blue representing lower expression relative to UNIRR control (n = 3 mice/group). Arrowhead points to growth factor gene of interest Igf1. (B) Quantitative reverse transcriptase polymerase chain reaction (qPCR) analysis of Igf1 mRNA abundance post-irradiation. (C) Analysis of Igf1 mRNA abundance by qPCR in intestinal epithelial or mesenchymal compartments, with validation of tissue fractionation by expression of villin (Vil) or vimentin (Vim), respectively. (D) RNAScope in situ hybridization (ISH) for Igf1 on UNIRR and 48 HPI duodenum. Arrowheads indicate some Igf1-expressing cells at the crypt base. (E) Single-cell RNA-seq analysis of IGF-1 receptor (Igf1r) expression in crypt cells. tSNE plots of cell clusters (left) and Igf1r expression (right). Quantitative data are displayed as mean ± SEM (n = 3 mice/group; ∗∗P < .01 by 1-way ANOVA with Dunnett post-test).