Dynamic histology of the antral epithelilum in the mouse stomach: IV. Ultrastructure and renewal of gland cells

Abstract

The renewal of gland cells was investigated by three-dimensional reconstruction of typical mucous units of the pyloric antrum using electron microscopy and 3H-thymidine radioautography in 3 to 4 month-old CD1 mice. Based on analysis of 42 units, the average gland measured 31 micron in length and was composed of 37 (mucous) gland cells with eight enteroendocrine cells scattered among them. The gland neck cells located close to the isthmus showed the cytoplasmic and nuclear features characteristic of differentiating cells. The mid-gland cells occupying the central portion of the gland appeared to be at a more advanced stage of development and completing differentiation. The gland base cells comprising the blunt end of the gland were fully mature. To quantify the renewal process, the percent of gland cell nuclei carrying label was determined at several times following 3H-thymidine administration. The rate of proliferation was found to be greatest in the gland neck, lower in the mid-gland, and even lower within the gland base. Furthermore, the isthmus contributed to gland-cell renewal by providing an estimated 12.4 cells per day. Labeled cells migrated toward the blunt end of the gland. The migration rate became progressively slower with their descent, and many cells were lost along the migration pathway, mainly in the gland neck. The loss took place without being preceded by gradual cell degeneration, but occurred as a result of rapid extrusion to the lumen or, less frequently by pyknosis, which could be followed by phagocytosis. It is concluded that the rapid rate of mitosis within the isthmus and gland neck generates a pressure causing downward migration of the cells toward the blunt end of the gland. The rate of migration, however, gradually diminishes as cells descend into the gland, presumably owing both to decreasing proliferation rate and to cell loss. Thus, while cells migrate down toward the gland base, many are lost before reaching it. This sequence is described as "the cascade pattern" of renewal.

Thyroid hormone-upregulated expression of Musashi-1 is specific for progenitor cells of the adult epithelium during amphibian gastrointestinal remodeling

“…It is noteworthy that Msi-1 expression is also expressed in the mammalian intestine (Sakakibara et al, 1996), where putative stem cells and at least the next two generations are positive for Msi-1 (Potten et al, 2003). Although Msi-1 expression became hardly detectable towards the end of metamorphosis, possibly due to a low immunoreactive sensitivity in this study, Msi-1 expression could be detectable in the region where proliferating cells were localized in both the intestine and the stomach, that is, in the trough of intestinal folds corresponding to the mammalian crypt (Cheng and Bjerknes, 1985;Potten et al, 1997) or in the neck region of gastric glands similar to that of mammalian glands (Lee and Leblond, 1985). These results indicate that the adult progenitor cells during amphibian metamorphosis include stem cells analogous to the mammalian ones, and molecular mechanisms underlying the control of these stem cells are conserved across the amphibian and mammalian gastrointestines.…”

“…Meanwhile, in the stomach, the adult epithelium acquires the cell renewal system where proliferating cells are localized in the neck region of glands (Oinuma et al, 1992) similar to that of the mammalian gastric glands (Lee and Leblond, 1985;Nomura et al, 1998), and finally differentiates into the surface mucous epithelium and the glandular epithelium, which consists of major glandular cells expressing pepsinogen (Pg) (Inokuchi et al, 1995;Ishizuya-Oka et al, 1998), mucous neck cells, and endocrine cells (Holmberg et al, 2001). Therefore, it is suggested that progenitor cells of the adult epithelium that appear as undifferentiated cells during metamorphosis in these organs include multipotent stem cells analogous to those in the mammalian gastrointestine.…”

Multipotential stem cells in adult mouse gastric epithelium

“…Parietal, enteroendocrine, and caveolated cells migrate in both directions (15,17,20,(22)(23)(24)(25)29). In the antrum, units are similarly organized but consist mostly of mucous cells, although parietal and enteroendocrine cells are also found in some antrum units (18,27,30).…”

“…Some of the granulefree cells located in the isthmus are proposed to act as multipotential stem cells giving rise to prepit, preparietal, and preneck cells, which then act as progenitors committed to their respective cell lineages (22,25,30). However, there is no direct evidence in the adult stomach for multipotential stem cells.…”

Histochemical and biochemical analysis of phospholipase C isoforms in normal human gastric mucosa cells

“…The latter is the largest part of the gland and contains chief cells, parietal cells and sporadic mucous cells. Isolated endocrine cells can be found in all glandular tracts (Lee and Leblond, 1985). Among the molecular signals that regulate the activity of gastric cells, Fig.…”