Department of Surgery, Divison of Pediatric Surgery at Yale University, 330 Cedar St., FMB 131, New Haven, CT, United States of America.
Department of Surgery, Divison of Pediatric Surgery at Yale University, 330 Cedar St., FMB 131, New Haven, CT, United States of America.
Life Sci. 2020 Nov 1;260:118428. doi: 10.1016/j.lfs.2020.118428. Epub 2020 Sep 12.
The benefits of utilizing laboratory mice include low cost, ease of maintenance, and accessibility of molecular tools. However, the ages of experimental mice in the literature vary drastically. We hypothesized that there exists age-related variation in the murine small intestine across developmental stages.
Segments of small intestine were harvested from C57BL/6J mice of varying ages (E17 to 24 weeks; n = 3-4/group). Slides were analyzed for morphometric parameters, cell types, and crypt proliferation index (CPI). Secondary analysis comparing age-matched males and females (n = 4/group) was performed. Means were compared with Student's t-test and variance of proportions with the Chi-squared test to a significance of p < 0.05.
There were small but significant differences including regional variation in villus height, which abolished when examining the small intestine as a whole. Sexually immature mice had increased CPI compared to mature animals. The most dramatic differences were seen in mice at weaning, which demonstrated shallower crypts, increased CPI, fewer Paneth and goblet cells, and more enterochromaffin cells. Examination of embryonic intestine revealed an underdeveloped mucosa lacking differentiated cells. There were minimal differences when comparing age-matched males and females.
Small, but statistically significant differences in villus height, crypt depth, and crypt proliferation are present in mice across early developmental stages. Mice at weaning exhibit variation in crypt-villus cell composition compared to older animals, which may explain the propensity for certain intestinal conditions in the very young. Investigators studying the GI mucosa should employ consistent age-matching in order to allow direct comparison between studies.
利用实验小鼠的优点包括成本低、易于维护和易于获得分子工具。然而，文献中实验小鼠的年龄差异很大。我们假设在不同发育阶段的小鼠小肠中存在与年龄相关的变化。
从小鼠的不同年龄（E17 至 24 周；n=3-4/组）中采集小肠段。对切片进行形态计量学参数、细胞类型和隐窝增殖指数（CPI）分析。对年龄匹配的雄性和雌性（n=4/组）进行了二次分析。使用学生 t 检验比较平均值，使用卡方检验比较比例方差，p<0.05 具有统计学意义。
尽管存在微小但显著的差异，包括绒毛高度的区域差异，但当整个小肠进行检查时，这种差异就消失了。未成熟的性成熟小鼠的 CPI 高于成熟动物。在断奶的小鼠中，差异最为显著，其隐窝较浅、CPI 增加、潘氏细胞和杯状细胞减少、肠嗜铬细胞增多。对胚胎肠的检查显示，黏膜发育不全，缺乏分化细胞。在比较年龄匹配的雄性和雌性时，差异最小。
在早期发育阶段，小鼠的绒毛高度、隐窝深度和隐窝增殖存在微小但有统计学意义的差异。与老年动物相比，断奶期的小鼠隐窝-绒毛细胞组成存在差异，这可能解释了某些肠道疾病在非常年幼时发生的原因。研究胃肠道黏膜的研究人员应采用一致的年龄匹配，以便在研究之间进行直接比较。
