Inflammation and Proliferation Act Together to Mediate Intestinal Cell Fusion
Figure 3
Increased epithelial proliferation occurred after gamma-irradiation.
Wild-type (WT) mice were transplanted with GFP-expressing whole bone marrow (WBM). The distal small intestine was analyzed at 24 h increments for 1 week. (A–B) At 1 day post-transplantation, few GFP-positive cells (green) were located in the mesenchyme (arrowheads) and none were found in the epithelium. (C–D) H&E and Ki67 detection (red) with Hoechst dye (blue) indicated normal morphology at one day post-transplant. (E–F) At 4 days post-transplant, more GFP-positive cells were found surrounding the crypt (arrowheads), while none were detected in the epithelium. (G–H) H&E and Ki67 staining (red) revealed a dramatic increase in proliferation of the crypts. (I–J) By 7 days post-transplant, single plane confocal microscopy depicts the presence of GFP-positive cells in the mesenchyme surrounding the crypt as well as in the villi core (red arrowheads). GFP-positive epithelium was observed in the stem cell (yellow arrowheads) and transient-amplifying (yellow bracket) zones of crypts. Epithelial cells are marked with antibodies against E-cadherin (red). (K–L) H&E and Ki67 staining depicted morphology close to normal by 7 days post-transplant. Dashed white lines indicate epithelial/mesenchymal border. Red boxes in (A,E,I) are displayed in higher magnification in (B,F,J). Yellow brackets denote the depth of the Ki67-positive cells in (C,G,K). The nuclear dye Hoechst is depicted in grayscale in (A,E,I) and in blues in (D,H,L). D & H are the same tissue sections as A & E, respectively. Bars = 25 µm.