消化
词汇介绍
拓展阅读
解析
intestinal 英 [ˌɪntes'taɪnl] 美 [ɪnˈtɛstənəl]
释义 adj. 肠的
例句 Normal intestinal absorption is a complex process. 正常的消化道吸收功能是一个复杂的过程。
stem 英 [stem] 美 [stem]
释义 n. 干;茎;船首;血统
vt. 阻止;除去…的茎;给…装柄
vi. 阻止;起源于某事物;逆行
例句 But the flow from the stem tip prevents them from doing this.
但是,来自主干顶端的(激素)流会阻止它们这么做。
cell 英 [sel] 美 [sel]
释义 n. 细胞;电池;蜂房的巢室;单人小室
vi. 住在牢房或小室中
n. (Cell)人名;(英)塞尔
复数 cells
例句 Inside every cell in all organisms, there are strands of DNA. 所有生物的每个细胞内部都存在DNA分子链。
概述
概述
肠道干细胞(intestinal stem cells,ISCs)位于肠黏膜隐窝基底部,即基底隐窝是肠道干细胞的细胞库。正常情况下,位于隐窝基底部的肠道干细胞不断向隐窝顶部(肠腔方向)迁移,整个迁移过程大约3-5d,在迁移过程中肠道干细胞分化形成不同的肠黏膜细胞。
生理功能
定植在隐窝底部的肠道干细胞(intestinal stem cells,ISCs)不断分裂生成新的肠道干细胞或其子代细胞—过渡扩增细胞(transit amplifying cells,TA细胞),TA细胞在离开隐窝底部后不断增殖并分化为各类成熟肠上皮细胞,这些细胞相互挤压推动向肠绒毛顶端迁移,补充绒毛顶端凋亡脱落的肠上皮细胞。肠道上皮组织稳态有赖于ISCs保持自我更新(维持干细胞库)和分化为子代细胞(TA细胞并最终分化为各类成熟肠上皮细胞)之间的动态平衡。
影响ISCs增殖分化的因素
(1)能量;
(2)锌;
(3)维生素D3;
(4)谷氨酰胺;
(5)细菌代谢产物。
临床意义
ISCs处于一个复杂的微环境之中,来自于干细胞巢、肠内营养及微生物代谢产物、内分泌系统等多方面因素协同调节ISCs功能,维持肠道上皮稳态,这种稳态的破坏将导致动物营养不良或者肿瘤的发生。
检测方法
干细胞标记、诱导谱系示踪(lineage tracing)、类器官(organoid)培养等技术。
Tracing the origin of adult intestinal stem cells复制标题
成人肠干细胞的起源追踪
发表时间:2019-06-06
影响指数:43.1
作者: Jordi Guiu
期刊:Nature
Adult intestinal stem cells are located at the bottom of crypts of Lieberkühn, where they express markers such as LGR51,2 and fuel the constant replenishment of the intestinal epithelium1. Although fetal LGR5-expressing cells can give rise to adult intestinal stem cells3,4, it remains unclear whether this population in the patterned epithelium represents unique intestinal stem-cell precursors. Here we show, using unbiased quantitative lineage-tracing approaches, biophysical modelling and intestinal transplantation, that all cells of the mouse intestinal epithelium-irrespective of their location and pattern of LGR5 expression in the fetal gut tube-contribute actively to the adult intestinal stem cell pool. Using 3D imaging, we find that during fetal development the villus undergoes gross remodelling and fission. This brings epithelial cells from the non-proliferative villus into the proliferative inter villus region, which enables them to contribute to the adult stem-cell niche. Our results demonstrate that large-scale remodelling of the intestinal wall and cell-fate specification are closely linked. Moreover, these findings provide a direct link between the observed plasticity and cellular reprogramming of differentiating cells in adult tissues following damage5–9, revealing that stem-cell identity is an induced rather than a hardwired property.
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