Institute of Molecular Biology and Medicinal Chemistry, Otto-von-Guericke-University Magdeburg, Leipziger Str. 44, D-39120 Magdeburg, Germany.
Curr Med Chem. 2012;19(35):5975-83.
The gastric mucosa and its glands show continuous bidirectional self-renewal via differentiation from stem and progenitor cells. Here, two types of gastric units, i.e., fundic and antral units, form delicate homeostatic systems. This review focuses on recent developments concerning the different types of gastric stem cells, the central function of parietal cells as organizing centres of fundic units, the stepwise differentiation of zymogenic cells via trans-differentiation of mucous neck cells, and unexpected differences between fundic and antral surface mucous cells. Within the last years, the central role of Sonic hedgehog (Shh) for correct self-renewal of fundic units has become much clearer. Furthermore, also the knowledge concerning the genesis of gastric cancer increased substantially. Here, chronic inflammation leads to dysregulated differentiation processes and finally to cancer. Remarkable progress has been made particularly concerning the genesis of two metaplastic cell lineages, i.e., the TFF2/spasmolytic polypeptide expressing metaplasia (SPEM) and intestinal metaplasia, which both arise in intestinal-type cancers in fundic units by dysregulated trans-differentiation of the zymogenic cell lineage. Additionally, Shh has been recognized as a target for inflammatory processes and an important player for innate immunity processes. Thus, stem cells, self-renewal, and gastric cancer are intimately linked.
胃黏膜及其腺体通过干细胞和祖细胞的分化实现连续的双向自我更新。在这里，两种胃单位，即胃底单位和胃窦单位，形成了精细的稳态系统。本文综述了近年来关于不同类型胃干细胞、壁细胞作为胃底单位组织中心的核心功能、通过粘液颈细胞的转分化逐步分化为酶原细胞，以及胃底和胃窦表面粘液细胞之间出人意料的差异等方面的最新进展。在过去的几年中，Sonic hedgehog（Shh）对于胃底单位正确的自我更新的核心作用变得更加清晰。此外，关于胃癌的发生也有了实质性的进展。在这里，慢性炎症导致分化过程失调，最终导致癌症。特别在两个化生细胞谱系的发生方面取得了显著进展，即 TFF2/舒血管肠肽表达化生（SPEM）和肠化生，它们都是通过酶原细胞谱系的失调转分化在胃底单位的肠型癌症中产生的。此外，Shh 已被认为是炎症过程的靶点和先天免疫过程的重要参与者。因此，干细胞、自我更新和胃癌密切相关。
