Fig. 1

The colon epithelium of IL-37-transgenic mice exhibits balanced homeostasis. a Representative H&E-stained sections (left, scale bar: 50 μm) of the distal colon of IL-37tg mice and WT mice, and quantification of the crypt length (right) is shown. At least 15 well-oriented crypts were measured on slides from each mouse, n = 5/group. b Representative alcian blue and PAS staining of distal colon sections obtained from IL-37tg mice and WT mice (left, scale bar: 50 μm). Statistical analysis of enumeration of goblet cells per crypt (right), at least 15 well-oriented crypts were measured on slides from each mouse, n = 5/group. c 50 mg/kg BrdU was administrated to IL-37tg mice and WT mice by intraperitoneal injection. The colon sections were harvested and stained for BrdU-positive cells at 24 h after BrdU injection. Representative BrdU-stained sections are shown (left, scale bar: 50 μm). Statistical analysis of BrdU-positive cells per crypt (right), at least 15 well-oriented crypts were counted on slides from each mouse, n = 5/group. d DNA fragmentation in the colon of IL-37tg mice and WT mice was detected by in situ TUNEL assay. Apoptotic cells were stained brown and nuclei were stained blue by hemotoxylin, at least 15 Well-oriented crypts were counted on slides from each mouse, scale bar: 50 μm, n = 5/group. e Immunoblotting was performed to detect CDK4 and Bcl-xL in colon epithelial cells from IL-37tg and WT mice. β-Actin was used as a loading control. f qRT-PCR analysis of indicated genes from the colons of IL-37tg mice and WT mice, n = 5/group. g The same amount of colon tissue from IL-37tg mice and WT mice was cut into small pieces and incubated in serum-free RPMI medium for 24 h. Secreted chemokines and cytokines in the medium were measured by ELISA assay, n = 5/group. h qRT-PCR analysis was performed for each indicated gene in colon tissues of IL-37tg mice and WT mice. n = 5/group. All data are presented as mean ± SD. Statistics analyzed by Two-tailed Student’s T-test. NS, not significant