Ficant increases in villous length (L) and villous width (W) in low expression TG mice in comparison to WT mice at 1 month of age in the duodenum (L: 623 77 vs. 459 11, p 0.001; W: 144 46 vs. 95 26, p 0.005), jejunum (L: 598 27 vs. 490 52, p 0.005; W: 125 27 vs. 85 23, p 0.005), and ileum (L: 241 46 vs. 181 41, p 0.05; W: 122 31 vs. 88 22, p 0.05) (Figure 4B). Interestingly, the villous length and width in the high expression TG mice at 1 month of age had been not statistically distinct from that of WT mice (Figure 4B). By five months of age, there had been no variations in villous height or villous width in any with the groups of mice except for slight variations inside the duodenum. There were no CD93 Proteins site differences in crypt depth amongst any with the groups of miceNIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author ManuscriptGrowth Things. Author manuscript; obtainable in PMC 2013 November 08.CHEN et al.Pageat either 1 or 5 months of age with all the exception of your ileum of low expression and high expression TG mice at 1 month of age (Figure 4B). Overexpression of HB-EGF was connected with enhanced duodenal and ileal muscularis externa thickness in mice at 1 month of age (Figure 4B). Low expression TG mice had the thickest muscular layers. This effect was no longer observed at five months of age, exactly where WT mice had thicker muscle layers in comparison to TG mice. Within the low expression TG mice, enterocyte cell and nuclear volumes within the jejunum and ileum of 1 month old TG mice had been mildly increased compared to WT mice (Figure 4C), resulting in lower enterocyte density (jejunum: 24.two 3.7 vs. 30.2 4.3 cells/10 .. m, p 0.05; ileum: 24.1 2.7 vs. 30.8 four.1 cells/10 .. m, p 0.01, (Figure 4D). There had been no variations in enterocyte density amongst higher expression TG mice and WT mice. As a result of the theoretical concern of no matter if long-term overexpression of HB-EGF could result in hyperplasia or tumor formation in mouse intestine, we examined the tiny and massive intestine of older age low expression and higher expression HB-EGF TG mice. There was no proof of hyperplasia, polyps, or tumor development observed in any TG mice at either 1 year (low, n = 2; high, n = four) or 1.five years (high, n = 8) of age (data not shown). Cell proliferation in HB-EGF TG mice BrdU IHC was employed to identify proliferating cells (Figure 5A). Crypt cell proliferative activity in low expression and high expression HB-EGF TG mice [duodenum (55.three four.8 ; 57.2 9.three), jejunum (52.two 2.1 ; 58.7 five.three), ileum (49.8 4.6 ; 55.6 five.3), and colon (20.5 3.2 ; 20.7 8.9)] was larger than that of WT control mice [duodenum (43 9.0), jejunum (48.1 four.three), ileum (43.6 5.0), and colon (eight.7 0.eight)] at 1 month of age (Figure 5B). The variations in proliferative activity amongst higher expression TG mice and WT mice persisted at five months of age. Even so, the proliferation indices in low expression TG mice showed no differences in comparison with WT mice in the jejunum and ileum at 5 months of age. Given that proliferative cells are derived from SCs, we subsequent examined the impact of HB-EGF overexpression on SCs. SCs under cell +4 level within the jejunum of WT, low expression TG mice, and high expression TG mice at 1 month of age had been identified by anti-prominin-1 antibody immunostaining (Figure 5C). There were no important variations inside the number of SCs per crypt (Figure 5D) or within the quantity of proliferating SCs per crypt (Figure 5E) involving WT mice and HB-EGF TG mice. Cellular apoptosis in HB-EGF TG mice 4-1BBL/CD137L Proteins Molecular Weight Apoptotic cell death was examined in the epi.