Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina.
Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina.
Cell Mol Gastroenterol Hepatol. 2019;8(4):549-560. doi: 10.1016/j.jcmgh.2019.07.003. Epub 2019 Jul 19.
Paneth cells are professional secretory cells found within the small intestinal crypt epithelium. Although their role as part of the innate immune complex providing antimicrobial secretory products is well-known, the mechanisms that control secretory capacity are not well-understood. MIST1 is a scaling factor that is thought to control secretory capacity of exocrine cells.
Mist1 and Mist1 mice were used to evaluate the function of MIST1 in small intestinal Paneth cells. We used histologic and immunofluorescence staining to evaluate small intestinal tissue for proliferation and lineage allocation. Total RNA was isolated to evaluate gene expression. Enteroid culture was used to evaluate the impact of the absence of MIST1 expression on intestinal stem cell function.
Absence of MIST1 resulted in increased numbers of Paneth cells exhibiting an intermediate cell phenotype but otherwise did not alter overall epithelial cell lineage allocation. Muc2 and lysozyme staining confirmed the presence of intermediate cells at the crypt base of Mist1 mice. These changes were not associated with changes in mRNA expression of transcription factors associated with lineage allocation, and they were not abrogated by inhibition of Notch signaling. However, the absence of MIST1 expression was associated with alterations in Paneth cell morphology including decreased granule size and distended rough endoplasmic reticulum. Absence of MIST1 was associated with increased budding of enteroid cultures; however, there was no evidence of increased intestinal stem cell numbers in vivo.
MIST1 plays an important role in organization of the Paneth cell secretory apparatus and managing endoplasmic reticulum stress. This role occurs downstream of Paneth cell lineage allocation.
潘氏细胞是存在于小肠隐窝上皮内的专业分泌细胞。虽然它们作为提供抗菌分泌产物的先天免疫复合物的一部分的作用是众所周知的，但控制分泌能力的机制还没有很好地理解。MIST1 是一种缩放因子，被认为控制着外分泌细胞的分泌能力。
使用 Mist1 和 Mist1 小鼠来评估 MIST1 在小肠潘氏细胞中的功能。我们使用组织学和免疫荧光染色来评估小肠组织的增殖和谱系分配。分离总 RNA 以评估基因表达。使用肠类器官培养来评估缺乏 MIST1 表达对肠干细胞功能的影响。
缺乏 MIST1 导致表现出中间细胞表型的潘氏细胞数量增加，但不会改变上皮细胞谱系分配的整体情况。Muc2 和溶菌酶染色证实 Mist1 小鼠的隐窝底部存在中间细胞。这些变化与与谱系分配相关的转录因子的 mRNA 表达变化无关，并且不会被 Notch 信号转导抑制所消除。然而，缺乏 MIST1 表达与潘氏细胞形态的改变有关，包括颗粒大小减小和粗面内质网扩张。缺乏 MIST1 与肠类器官培养物的出芽增加有关；然而，在体内没有证据表明肠干细胞数量增加。
MIST1 在潘氏细胞分泌装置的组织和管理内质网应激中发挥重要作用。这种作用发生在潘氏细胞谱系分配的下游。
