Identifying and counting epithelial cell types in the “corpus” of the mouse stomach

The epithelial cells lining the oxyntic mucosa in the stomach “corpus” were identified, localized, and counted in 2-month-old male C57BL-6 mice, using glutaraldehyde-formaldehyde fixation and osmium tetroxide postfixation for studies in the light microscope (LM) while adding tannic acid to the fixative and postfixing in ferrocyanide-osmium for studies in the electron microscope (EM). The cells form a single epithelium, which invaginates into blind tubular units. Each unit is divided into four successive regions: pit, isthmus, neck, and base. On the average, a unit contains 194.2 cells. The cells have been classified into three groups totaling 11 types, listed with their mean number per unit. The first group is composed of three well-characterized cell types, each restricted to a region: (1) 37.0 surface mucous cells, hereafter called pit cells, in the “pit” region, (2) 12.6 mucous neck cells, simply called neck cells, in the “neck” region, and (3) 67.4 zymogenic cells in the “base” region. The second group is also composed of three well-characterized cell types, distributed over the four regions: (1) 26.0 parietal cells, (2) 13.2 entero-endocrine cells, and (3) 0.6 caveolated cell. The third group consists of five cell types, which have been little or not characterized in the past. Four are located in the “isthmus” region and show EM features indicative of immaturity, that is, a nucleus with mainly diffuse chromatin and large reticulated nucleoli, and a scanty cytoplasm rich in free ribosomes: (1) 17.2 cells are the least differentiated in the epithelium; they are devoid of secretory granules and accordingly named granule-free cells, (2) 10.0 cells contain a few dense secretory granules smaller than, but otherwise similar to, those in pit cells; they are referred to as pre-pit cells, (3) 1.8 cells possess a few marbled secretory granules that often exhibit a pale core and are smaller than, but otherwise similar to, those in neck cells; they are called pre-neck cells, (4) 0.6 cells display long microvilli and/or small canaliculi similar to those in parietal cells; they are named pre-parietal cells, and (5) 5.6 cells restricted to the base region are characterized by secretory granules with features intermediate between those of neck and zymogenic cells; they are named pre-zymogenic cells. The observations suggest the following hypothesis on cell filiation. The granulefree cells would function as stem cells and give rise to pre-pit, pre-neck, and preparietal cells, which would, respectively develop into pit, neck, and parietal cells; neck cells would then transform into pre-zymogenic cells, which would finally become zymogenic cells. Entero-endocrine and caveolated cells would come directly from the postulated stem cell.     

Identifying and counting epithelial cell types in the "corpus" of the mouse stomach.

The epithelial cells lining the oxyntic mucosa in the stomach "corpus" were identified, localized, and counted in 2-month-old male C57BL-6 mice, using glutaraldehyde-formaldehyde fixation and osmium tetroxide postfixation for studies in the light microscope (LM) while adding tannic acid to the fixative and postfixing in ferrocyanide-osmium for studies in the electron microscope (EM). The cells form a single epithelium, which invaginates into blind tubular units. Each unit is divided into four successive regions: pit, isthmus, neck, and base. On the average, a unit contains 194.2 cells. The cells have been classified into three groups totaling 11 types, listed with their mean number per unit. The first group is composed of three well-characterized cell types, each restricted to a region: (1) 37.0 surface mucous cells, hereafter called pit cells, in the "pit" region, (2) 12.6 mucous neck cells, simply called neck cells, in the "neck" region, and (3) 67.4 zymogenic cells in the "base" region. The second group is also composed of three well-characterized cell types, distributed over the four regions: (1) 26.0 parietal cells, (2) 13.2 entero-endocrine cells, and (3) 0.6 caveolated cell. The third group consists of five cell types, which have been little or not characterized in the past. Four are located in the "isthmus" region and show EM features indicative of immaturity, that is, a nucleus with mainly diffuse chromatin and large reticulated nucleoli, and a scanty cytoplasm rich in free ribosomes: (1) 17.2 cells are the least differentiated in the epithelium; they are devoid of secretory granules and accordingly named granule-free cells, (2) 10.0 cells contain a few dense secretory granules smaller than, but otherwise similar to, those in pit cells; they are referred to as pre-pit cells, (3) 1.8 cells possess a few marbled secretory granules that often exhibit a pale core and are smaller than, but otherwise similar to, those in neck cells; they are called pre-neck cells, (4) 0.6 cells display long microvilli and/or small canaliculi similar to those in parietal cells; they are named pre-parietal cells, and (5) 5.6 cells restricted to the base region are characterized by secretory granules with features intermediate between those of neck and zymogenic cells; they are named pre-zymogenic cells. The observations suggest the following hypothesis on cell filiation.(ABSTRACT TRUNCATED AT 400 WORDS)     

Dynamics of epithelial cells in the corpus of the mouse stomach. I. Identification of proliferative cell types and pinpointing of the stem cell

In a recent study of the corpus epithelium in the mouse stomach, eleven cell types have been identified and enumerated (Karam and Leblond: Anat. Rec. 232:231–246, 1992). The dynamics of these cells will be examined in a series of five articles, of which this is the first. This article focuses on the proliferative ability of the cells, as measured by the labeling index in radioautographs from mice sacrificed 30 min after an intravenous injection of ³H-thymidine. Furthermore, the ultrastructure of the cells found to be proliferative was examined in the hope of finding features characteristic of stem cells. On the basis of their labeling index, the epithelial cells have been classified into four groups. The first includes three cell types which do not take up any label and accordingly are non-dividing: parietal or oxyntic cells, cells named pre-parietal as they are immature cells suspected of being parietal cell precursors, and the rare caveolated or brush cells. The second group is composed of three cell types which are only rarely labeled and, therefore, divide only occasionally: zymogenic or chief cells, entero-endocrine cells, and cells named pre-zymogenic cells as they are suspected of being zymogenic cell precursors. The third group includes two cell types which are always labeled at a low degree and, therefore, divide regularly, but at a low rate: surface mucous cells, herein called pit cells, whose labeling index is 0.8%, and mucous neck cells, simply known as neck cells, 1.8%. The final group consists of three immature cell types with high labeling indices indicating a high rate of division: granule-free cells, which are devoid of secretory granules and have the highest labeling index, 32.4%, prepit cells, which possess a few dense secretory granules similar to, but smaller than, those in pit cells, 24.6%, and pre-neck cells, with a small number of secretory granules similar to, but smaller than, those in neck cells, 11.3%. These three cell types, as well as pre-parietal cells, are rapidly renewed, with the turnover times estimated at 3.0 days for pre-neck and pre-parietal cells and less than 2.6 days for granule-free and pre-pit cells. Ultrastructural studies of granule-free cells reveal that they may be sub-divided into three subtypes according to their Golgi features: subtype I, which consists of undifferentiated cells in which the Golgi trans face exhibits no prosecretory vesicles; subtype II, named pre-pit cell precursors because the Golgi trans face shows prosecretory vesicles similar to those in pre-pit cells; and subtype III, named pre-neck cell precursors, whose prosecretory vesicles are similar to those in pre-neck cells. On the other hand, pre-parietal cells include three variants that could each arise from a different granule-free subtype: variant I, which has no mucous secretory granules, could arise from the undifferentiated cells; variant II, which possesses dense mucous granules similar to those in pre-pit cells, could come from pre-pit cell precursors; and variant III, which has cored granules as in pre-neck cells, could come from pre-neck cell precursors. Only the undifferentiated granule-free cells have the features expected from stem cells and, therefore, are considered to be the stem cells of the epithelium. A model based on the radioautographic and morphological data (Fig. 17) summarises the filiation of the other immature cell types as follows. The undifferentiated granule-free cells as stem cells reproduce themselves and give rise to three other cell types: (1) the pre-parietal cells lacking secretory granules (i.e., variant I); (2) the pre-pit cell precursors, which mainly give rise to pre-pit cells, but also yield the variant II pre-parietal cells; (3) the pre-neck cell precursors, which mainly give rise to pre-neck cells, but also yield the variant III pre-parietal cells. Further differentiation of these immature cell types into the other cells of the corpus epithelium is examined in the succeeding articles. © 1993 Wiley-Liss, Inc.     

Dynamics of epithelial cells in the corpus of the mouse stomach. III. Inward migration of neck cells followed by progressive transformation into zymogenic cells

The neck cells (or mucous neck cells) present in the neck region and the zymogenic cells (or chief cells) present in the base region of the units in the mouse corpus were examined in the electron microscope (EM) and in radioautographs prepared after administration of ³H-thymidine by single or multiple injections or by continuous infusion for 1–52 days. For these studies, the neck region of the units has been subdivided into three equal segments, respectively named high neck, mid neck, and low neck, while the base region has been similarly subdivided into high base, mid base, and low base. The neck region includes an average of 12.6 neck cells, characterized in the EM by dark, mucous secretory granules that frequently exhibit a light, pepsinogenic core. Continuous ³H-thymidine infusion reveals that neck cells come from pre-neck cells, which are believed to arise in the isthmus region from the undifferentiated granule-free cells through a pre-neck cell precursor stage. The pre-neck cells, characterized by the presence of a few cored secretory granules, migrate inward (i.e., in the direction of the blind end of the units) and enter the neck region to become neck cells. It is estimated that 59% of the neck cells arise from differentiation of pre-neck cells, whereas the other 41% are derived from their own mitoses. Neck cells migrate inward in 1–2 weeks from the high through the mid and low neck segments, while they keep on producing more and larger secretory granules and thus further differentiate as mucus-producing cells. When neck cells reach the high base segment, they become pre-zymogenic cells that produce secretory granules in which appear light, irregular, pepsinogenic patches which encroach on the dark mucous content. With time, the pre-zymogenic cells, of which there are 5.0 per unit on the average, keep on producing new granules with larger and larger light patches, so that in the end the cells produce granules which are entirely filled by light, pepsinogenic material. At this stage, the cells are zymogenic cells. Zymogenic cells, which average 67.5 per unit, further migrate inward, while gradually enlarging and producing pepsinogenic granules of increasing size. In the low base segment, some zymogenic cells show signs of degeneration leading to death by either necrosis or apoptosis. While remnants of the necrotic cells appear to be released to the unit lumen, the apoptotic cells are phagocytosed by a neighboring zymogenic cell or by a connective tissue macrophage breaking through the basement membrane of the oxyntic unit. Briefly, the zymogenic cell lineage, a cell sequence initiated from the stationary undifferentiated granule-free cells, includes pre-neck cell pre-cursors, pre-neck cells, neck cells, pre-zymogenic cells, and finally zymogenic cells, which all migrate in the direction of the unit's blind end, near which zymogenic cells are lost. © 1993 Wiley-Liss, Inc.     

Oxyntic cell differentiation during physiological cell renewal in abomasal mucosa of adult cattle

The origin and differentiation of the oxyntic cell lineage during physiological cell renewal was investigated by light and electron microscopy in the abomasal mucosa of adult cattle. The morphologically heterogeneous oxyntic cell population exhibits various developmental subtypes depending on the position within the oxyntic unit. Pre-oxyntic cells of the isthmus and neck represent the immature precursors. Though heterogeneous with respect to the degree of canalicular and tubulovesicular membrane development, they all contain secretory granules resembling those of either isthmus cells, immature surface mucous cells, neck cells or young chief cells. A secretory granule-free stem cell is not present in the bovine. Downward to the gland base genesis of canalicular as well as tubulovesicular membranes is gradually completed; thus pre-oxyntic cells give rise to mature oxyntic cells. Older degenerative oxyntic cells, primarily located within the gland bottom, are characterized by progressive involution of canalicular and tubulovesicular membranes. Towards the pit, differentiation of pre-oxyntic cells is associated with atypical and incomplete development of canaliculi and tubulovesicles. In consequence, these superficial oxyntic cells have a reduced secretory capacity from a morphological point of view.     

Dynamics of epithelial cells in the corpus of the mouse stomach. IV. Bidirectional migration of parietal cells ending in their gradual degeneration and loss

The life story of parietal cells has been investigated in the corpus of the mouse stomach using electron microscopy and ³H-thymidine radioautography. Parietal cells are scattered in the four regions of the unit. On the average 3.6 cells are in the pit, 6.2 in the isthmus, 5.6 in the neck, and 10.6 in the base. Parietal cells do not divide. They arise from partially differentiated pre-parietal cells, which are believed to be derived in the isthmus from the three subtypes of granule-free cells: undifferentiated cells, pre-pit cell precursors, and pre-neck cell precursors. Radioautography indicates that the transformation of granule-free cells into pre-parietal cells takes at least one day. The pre-parietal cells, of which there are 0.6 per unit on the average, develop into parietal cells through three successive stages. Stage 1 is characterized by small immature cells that are identified by long apical microvilli. Stage 2 is characterized by larger cells, about one-third the size of parietal cells, and by an incipient canaliculus and a few apical tubulovesicles. Stage 3 is characterized by the expansion of the canalicular and tubulovesicular systems as well as mitochondrial enlargement, which cause the pre-parietal cell to gradually approach the size of, and eventually become, a parietal cell. This cell sequence mainly takes place in the isthmus, but may extend to the neck region. Continuous infusion of ³H-thymidine confirms that parietal cells originate in the isthmus and that they migrate in two directions: some go outward to the pit and the others migrate inward to the neck and eventually to the base. It has been estimated that for every six parietal cells produced per month in the isthmus, three migrate to the pit and three migrate to the neck to eventually reach the base. While almost all parietal cells in the isthmus and neck appear normal, a large proportion of those reaching the pit (21%) and base (23%) undergo gradual alteration and degeneration. After the ensuing death, parietal cells are eliminated in one of two major ways: (1) extrusion into the gastric lumen, if they appear necrotic, or (2) phagocytosis by a neighboring cell or even by an invading connective tissue macrophage, if they are apoptotic. The overall turnover time of parietal cells averages 54 days. Briefly, a sequence of cells—the parietal cell lineage—is initiated in the isthmus, where the three subtypes of granule-free cells are presumed to give rise to pre-parietal cells, which then differentiate into parietal cells. Half of the parietal cells migrate away in the direction of the gastric lumen and gradually degenerate as they approach the free surface, while the other half migrate in the other direction toward the unit's blind end, where they degenerate and are eliminated. © 1993 Wiley-Liss, Inc.     

Dynamics of epithelial cells in the corpus of the mouse stomach. II. Outward migration of pit cells

The pit cells (or surface mucous cells) present along pit walls and gastric surface have been investigated by electron microscopy and radioautography after a pulse or continuous infusion of ³H-thymidine. For these studies, the pit region has been subdivided into four segments: three of equal length along the pit wall, respectively named low pit, mid pit and high pit, and a last one at the surface named pit top. The pit region includes an average of 37 pit cells, characterized by dense mucous granules accumulated along the apical membrane in an organelle-free zone referred to as ectoplasm. Continuous ³H-thymidine infusion reveals that pit cells come from pre-pit cells, which are believed to arise in the isthmus region from the undifferentiated granule-free cells through a pre-pit cell precursor stage. The pre-pit cells, characterized by the presence of a few mucous secretory granules scattered in the cytoplasm, migrate outward (i.e., in the direction of the gastric lumen). When the secretory granules line up along the apical membrane in the ectoplasm, the pre-pit cell becomes pit cell. It is estimated that 87% of pit cells differentiate from pre-pit cells, while the remaining 13% come from their own mitoses. Observations at successive times after a ³H-thymidine pulse demonstrate that pit cells, like pre-pit cells, migrate toward the gastric surface where they are eventually lost. The continuous ³H-thymidine infusion results indicate that this migration takes 3.1 days on the average. Cells spend almost a day in each pit wall segment. In the low pit segment, cells produce more and larger mucous secretory granules than do pre-pit cells. In the mid and high pit segments, the number and size of the granules generally keeps on increasing, thus indicating that mucous differentiation is progressing. The secretory granules arising in the Golgi apparatus of pit wall cells are mostly spherical; they retain this shape during the few minutes taken to cross the cytoplasm and enter the apical ectoplasm. They spend about an hour in the ectoplasm, where they change to an ovoid shape as they approach the apical membrane to finally release their content by exocytosis. The mucous differentiation along the pit wall is associated with a progressive decline in the organelles: nucleoli and mitochondria decrease in size while the amount of free ribosomes diminishes. When pit cells reach the free surface, they produce fewer, smaller secretory granules and at a lower rate than in mid and high pit. Meanwhile, organelles decline further, while mitochondria tend to swell and disintegrate. Clearcut signs of degeneration appear in some of the cells. These cells find their way into the gastric lumen either by direct extrusion or indirectly after being phagocytosed by a neighbor cell which is itself eventually extruded. Thus a sequence of cells—the pit cell lineage—derived from the stationary undifferentiated granule-free cells, includes pre-pit cell precursors, pre-pit cells, and pit cells, which all migrate in the direction of the gastric lumen, where pit cells are eventually lost. © 1993 Wiley-Liss, Inc.     

Retinoic acid stimulates the dynamics of mouse gastric epithelial progenitors

The gastric epithelial progenitors proliferate and undergo bipolar migration associated with their differentiation into pit, parietal, and zymogenic cell lineages. Retinoids have long been known to modulate proliferation and differentiation of various renewing epithelia, and the expression of their receptors has been demonstrated in the gastric mucosa. The aim of this study was to examine the effects of retinoic acid on progenitor cell proliferation and cell lineage formation in the mouse stomach. By using subcutaneously inserted osmotic pumps, mice were continuously infused with all-trans retinoic acid (5 mg/kg per day) for 3 days. To label S-phase cells and their progeny, bromodeoxyuridine was administered for different time intervals. Analysis of gastric mucosal tissues of retinoic acid-treated mice revealed a significant increase in the number of S-phase progenitor cells and an enhancement in the production of their progeny. The life span of pit cells was reduced, and their apoptosis became apparent at the luminal surface. Immunofluoresence probing of pit, parietal and enteroendocrine cell lineages in control and retinoic acid-treated mice showed no significant change in their labeling pattern. However, there was an increase in the labeled gland area of zymogenic cells. In conclusion, 3-day treatment of retinoic acid enhances the proliferation of gastric epithelial progenitors and the dynamics of their progeny.     

Foveolar differentiation of mouse gastric mucosa in vitro

We report a novel method that allows the culture of highly differentiated gastric surface mucous cells. Isolated mouse gastric epithelial cells and fibroblasts were co-cultured in a three-dimensional collagen gel system, and the reconstructed mucosal surface treated with an air-liquid interface. Cultured cells were examined by histology, immunohistochemistry, and electron microscopy. Isolated epithelial cells were positive for MUC5AC, and showed immature mucous cell features (pre-pit cell stage) on cell-free collagen gel. However, when given fibroblastic support, the epithelial cells differentiated into mature surface mucous cells (pit cell stage), and showed a tall columnar cell shape, basal round nuclei, and mucus-filled cytoplasm. In the fine structure, the cells showed junctional complexes, basal lamina, and glycogen and secretary granules. Further treatment by the air-liquid interface environment modified the differentiated state of the pit cells (pit top cell stage); resulting in the expression of cathepsin E, the disappearance of glycogen granules and the apical accumulation of secretory granules along with an increase in apoptotic cells. This culture model should provide a useful tool for studying gastric epithelial cell biology and various diseases of the gastric mucosa.     

Polychlorinated biphenyl-induced morphologic changes in the gastric mucosa of the rhesus monkey.

The early morphologic events in polychlorinated biphenyl-induced lesions of the gastric mucosa of immature male rhesus monkeys (Macaca mulatta) were studied in serial biopsies taken during consumption of diets containing 3, 10, 30, and 100 mg. per kg. (p.p.m.) of Aroclor 1242. The severity of the lesions correlated directly with both the duration and the level of exposure. The first changes were seen after ingestion of 30 and 100 mg. per kg. for 2 weeks; changes were not seen until 10 weeks at 3 and 10 mg. per kg. The principal effect was an apparent arrest of the differentiation of generative cells of the isthmus and neck regions into parietal and zymogenic (chief) cells. Mature parietal and zymogenic cells were found only in the bases of the glands, where the oldest cells are normally found, and these showed signs of injury including dilation of the rough endoplasmic reticulum in zymogenic cells, irregularity of the mitochondria in parietal cells and irregular luminal membranes, and an increase in the number of large autophagic vesicles in both cell types.     

Proliferation of the glandular epithelium of the resected rat stomach

Between 45 and 50% of the wall of the gastric fundus was resected in adult male rats. By pulse labeling and 5 injections of thymidine-H³ in the course of the 24 h an increase in the number of cells synthesizing DNA and the number of dividing cells of all types was found in the chief glands of the stomach during the first 3 days after resection. On the 5th–10th day the level of proliferation of all types of cells was lower than in intact animals except for the DNA-synthesizing parietal cells. The daily number of DNA-synthesizing cells of all types 3–6 months after the operation has risen to the characteristic level for intact animals. The number of cells on the surface and pit epithelium and the number of mucous neck and parietal cells were increased. Partial reduction and dedifferentiation of the zymogenic cells were observed.     

The ultrastructure of the gastric mucosa in normal and hypophysectomized rats

The objectives of this study were to observe with the electron micro scope (a) the epithelial cell types found in the neck and isthmus of the gastric fundic gland of the rat, and (b) the effects of hypophysectomy on the gland. The following cell types were distinguished in the neck of the fundic gland of the rat: nondifferentiated cell, immature surface cell, mucous neck cell, and neck parietal cell. In the normal gland, these cell types resembled each other in the possession of a ground cytoplasm and nucleoplasm of low density, a poorly developed endoplasmic reticulum, few mitochondria and numerous free ribosomes. The most important structural difference between mucous neck and immature surface cells was the contrasting density of the secretory granules; both cell types differed from the nondifferentiated cell primarily in the presence of their characteristic secretory granules. The neck parietal cell appeared to be a developmental form between the immature surface cell and the mature parietal cell. No changes were observed in these cells to result from hypophysectomy. Hypophysectomy caused marked involutional changes in the chief cell which involved mainly the organelles most directly concerned with protein synthesis, i.e., the ergastoplasm and Golgi apparatus. These effects were correlated with the loss of basophilia and secretory granules and with the reduction in cell size and capacity to secrete pepsinogen which were described previously. In contrast, the parietal cell, which is concerned with electrolyte transport, was affected much less.     

The mucous neck cell in the human gastric corpus: a distinctive,functional cell lineage

There is considerable debate about whether the mucous neck cell (MNC) in the mucosa of the gastric corpus is merely a transit cell population, intermediate between gastric stem cells and the differentiated zymogenic (chief or peptic) cell lineages, or has distinct functions of its own. To cast light on these possibilities, the secretory phenotype of the MNC has been examined. Archival gastric body samples from non-ulcer dyspepsia biopsies and gastrectomies performed for peptic ulcer disease were stained with antibodies to the trefoil peptides TFF1/pS2 and TFF2/SP, pancreatic secretory trypsin inhibitor (PSTI), epidermal growth factor (EGF) and its receptor (EGFR), and to the MUC1 gene product—HMFG2. Human MNCs express PSTI, TFF1/pS2, TFF2/SP, and EGF proteins, while rat MNCs express TFF2/SP; the mucin contained in the MNCs is diastase/periodic acid Schiff (D/PAS)-positive and stains with human milk fat globulin (HMFG2). The canaliculi but not the cytoplasm of adjacent parietal cells were also decorated focally by D/PAS, by HMFG2, and by antibodies to TFF2/SP and TFF1/pS2. These findings favour the hypothesis that MNCs have a defined phenotype and are thus a separate and distinct cell lineage, secreting a number of luminally-active peptides which protect the gastric mucosa, and in particular the adjacent parietal cells, from the effects of secreted gastric acid. Moreover, a considerable degree of similarity in secretory profile is noted between MNCs and the so-called ‘reparative lineages’ in the gut—the ulcer-associated cell lineage (UACL) and hyperplastic polyp epithelium. If, on the other hand, the MNCs are indeed a transit population differentiating into zymogenic or peptic cells, then it is clear that having differentiated into one secretory phenotype producing a range of peptides, the MNC then proceeds to differentiate into a cell with a totally different secretory phenotype, a phenomenon unique in gastrointestinal cell lineage relationships. Copyright © 1999 John Wiley & Sons, Ltd.     

IFNγ contributes to the development of gastric epithelial cell metaplasia in Huntingtin interacting protein 1 related (Hip1r)-deficient mice

Huntingtin interacting protein 1 related (Hip1r) is an F-actin- and clathrin-binding protein involved in vesicular trafficking that is crucial for parietal cell function and epithelial cell homeostasis in the stomach. Gastric parietal cells in Hip1r-deficient mice are lost by apoptotic cell death, which leads to a progressive epithelial cell derangement, including glandular hypertrophy, zymogenic cell loss and expansion of a metaplastic mucous cell lineage known as spasmolytic polypeptide-expressing metaplasia (SPEM). The epithelial cell changes are associated with infiltration of inflammatory cells. As inflammatory mediators, such as IFNγ, have been shown to contribute to the development of the gastric epithelial cell metaplasia after Helicobacter infection, we tested whether IFNγ played a role in the spontaneous progressive epithelial metaplasia observed in Hip1r-deficient mice. Hip1r-deficient mice were crossed with IFNγ-deficient mice and single- and double-mutant mice were analyzed at 3 and 12 months of age. Histopathology scoring showed that loss of IFNγ tempered the spontaneous development of metaplastic lesions in Hip1r-deficient mice. Loss of IFNγ was observed to abrogate the glandular hypertrophy evident in Hip1r mutant stomach, although increased epithelial cell proliferation and elevated gastrin levels were not affected by the presence or absence of this pro-inflammatory cytokine. An analysis of cell lineage markers in the double-mutant mice demonstrated that IFNγ specifically affected the development of metaplastic mucous cells in the neck region, whereas the parietal cell, surface mucous cell and zymogenic cell alterations remained similar to the histopathology in the Hip1r mutant. Morphometric analysis showed that IFNγ was required for the mucous cell hypertrophy and hyperplasia observed in Hip1r-deficient mice. Together, these findings demonstrate that IFNγ is critical for the development of the gastric epithelial cell metaplasia that results from parietal cell atrophy in the Hip1r-deficient mice.     

Light and electron microscopic investigation of the lectin-binding pattern in the oxyntic gland region of bovine abomasum.

For the first time the expression of glycoconjugate residues in the oxyntic gland region of bovine abomasum has been investigated by means of lectin histochemistry. For light microscopic investigations, a battery of ten lectins, Con A, PSA, UEA I, WGA, LEA, SNA, RCA120, MPA, DBA and SBA was used. For electron microscopic examinations, WGA and RCA120 were utilized. The staining pattern of the lectins in all exocrine cell types of the oxyntic gland region is described. Compared to the results of monogastric species our study reveals some similarities, but just as many differences in the composition of glycoconjugate residues in bovine exocrine cell types. Typical for surface mucous cells is the amount of L-fucose, N-acetyl glucosamine residues and Galbeta1, 4GlcNAc sequences in the secretory granules. SNA could serve as a marker for surface mucous cells, because this lectin exclusively stains the plasma membrane and the secretory granules of surface mucous cells and the extracellular mucus. L-fucose and N-acetyl glucosamine are typical for the secretory granules of mucous neck cells. In addition, the secretory granules show the highest amount of N-acetyl galactosamine residues of all exocrine cells, so that DBA and SBA are recommended as marker lectins for mucous neck cells. Most lectins strongly stain the intracellular membrane system of oxyntic cells. The cocktail of glycoconjugates in the vicinity of the HCI production site provide protection against chemical injury. In chief cells only the apical plasma membrane is more or less labeled with all lectins apart from SNA. Specific marker lectins for oxyntic cells or chief cells of the bovine have not been characterized.     

Down-regulation of a morphogen (sonic hedgehog) gradient in the gastric epithelium of Helicobacter pylori-infected Mongolian gerbils

Sonic hedgehog (Shh) is a morphogen involved in many aspects of patterning of the gut during embryogenesis and in gastric fundic gland homeostasis in the adult. Intestinal metaplastic change of the gastric epithelium is associated with the loss of Shh expression, and mice that lack Shh expression show intestinal transformation of the gastric mucosa. The present study was designed to investigate the alteration of Shh expression in the stomach of an experimental model of Helicobacter pylori (H. pylori) colonization. Male Mongolian gerbils were inoculated with H. pylori and examined 4 and 51 weeks later. The level of Shh mRNA expression was determined by quantitative RT-PCR and in situ hybridization. Shh protein expression was determined by immunoblotting and immunohistochemistry. Shh was expressed in the parietal cells, zymogenic cells, and mucous neck cells of the gastric fundic glands of gerbils. Prolonged colonization by H. pylori led to extension of the inflammation from the antrum to the corpus of the stomach, with loss of Shh expression. Loss of Shh expression correlated with loss of parietal cells, disturbed maturation of the mucous neck cell-zymogenic cell lineage, and increased cellular proliferation. Shh expression is significantly reduced in H. pylori-associated gastritis. These data show for the first time that H. pylori infection leads to down-regulation of the expression of a morphogen with an established role (Shh) in gastric epithelial differentiation.     

Do the cardiac glands exist? 7. The cow

The glands distributed in the narrow region of the abomasum contiguous to the omasum of the cow have been described as cardiac glands. We doubted this assertion and therefore performed histological and histochemical investigations of the glands to clarify their characteristics. 1. All glandular cells except the parietal cells in a few glands contiguous to the omasum react strongly to PAS, AB(pH 2.5), and PAS-AB(pH 2.5) staining, and moderately to AB(pH 0.5) staining. 2. Glandular cells at the base of these glands contain fine pepsinogen granules and a few parietal cells are distributed in these glands, indicating that they are undifferentiated gastric glands and that the so-called cardiac glands do not exist in the cow stomach. 3. Glandular cells in undifferentiated gastric glands are filled with PAS, AB(pH 2.5 and 0.5) and PAS-AB(pH 2.5) positive substances. Which gradually decrease and finally disappear with differentiation, remaining only in the neck (mucous neck cells) and the cells in the upper part of the glandular body (immature chief cells), in mature gastric glands. 4. Mature chief cells in differentiated gastric glands are distributed in the middle and lower bodies and base of the glands and contain a number of PAS and PAS-AB(pH 2.5) positive granules and a large number of coarse pepsinogen granules, while pepsinogen granules in the mucous neck cells and immature chief cells are finer. 5. In the cow the region in which undifferentiated gastric glands are located is very narrow. 6. Parietal cells in the cow stomach are numerous.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dynamics of epithelial cells in the corpus of the mouse stomach. V. Behavior of entero-endocrine and caveolated cells: General conclusions on cell kinetics in the oxyntic epithelium

Entero-endocrine cells and the rare cells named caveolated or brush cells have been examined in light microscopic radioautographs of the mouse corpus after various periods of continuous ³H-thymidine infusion. Moreover a search for immature forms and mitoses of these cells was undertaken in the electron microscope. Entero-endocrine cells are present in the four regions of the epithelial units, but their number is low in the pit, intermediate in the isthmus and neck, and high in the base. The labeling pattern after continuous ³H-thymidine infusion indicates that these cells are produced in the isthmus from undifferentiated granule-free cells presumed to be the stem cells of the epithelium, and may retain a limited ability to divide. A few of the newly formed entero-endocrine cells migrate to the pit, but the majority goes to the neck and, from there, to the base where they are present in relatively high numbers. Little information is available on the dynamics of caveolated cells. Since immature forms are present in the isthmus and mature ones in the other regions, it is concluded that they arise in the isthmus and migrate away in both directions. Finally, concluding remarks are presented on the kinetics of each one of the cell lineages described in this and the four previous articles. © 1993 Wiley-Liss, Inc.     

Lysozyme localization in normal and diseased human gastric and colonic mucosa. A correlative histochemical, immunohistochemical and immunoelectron microscopic investigation.

The distribution of lysozyme in normal and pathological human gastric and colonic mucosa was studied by light and electron microscopic immunocytochemical techniques and compared with histological and histochemical features. Lysozyme was localized in pyloric glandular epithelial cells, mucous neck cells of fundic glands, Paneth cells and some crypt cells of the mature colonic mucosa. In addition, lysozyme was detected in a large spectrum of "immature" or "regenerative" epithelium: neck cells of the gastric regenerative zone, undifferentiated columnar cells of surface and hyperplastic interfoveolar crests of the stomach, regenerative cells in a healed gastric ulcer, some goblet cells in incomplete intestinal metaplasia, cells of the regenerative zone at the bottom of colonic crypts and, finally, fetal intestinal epithelium. Electron microscopically, we localized lysozyme in the central core of mucous granules in the pyloric gastric glandular epithelium and in the dense mucous granules in gastric mucous neck cells. Lysozyme was also detected in some immature mucin-producing cells of the gastric regenerative zone and in the rough endoplasmic reticulum of surface hyperplastic columnar gastric cells. At the electron microscopic level, a peculiar correlation between the immunopattern of lysozyme and the morphology of mucous granules has been postulated. All our data support and extend the view that the presence of lysozyme may be related to cell immaturity as well as to a regenerative state of the cell. Finally, the lysozyme distribution and its relation to mucosubstances in gastric and colonic carcinoma suggest that lysozyme should not be considered an exclusive marker of cells of gastric derivation.     

Immunization with gastric H+/K(+)-ATPase induces a reversible autoimmune gastritis.

The gastric H+/K(+)-ATPase has been implicated as a major autoantigen in pernicious anaemia in humans and in thymectomy-induced autoimmune gastritis in mice. Here we have shown that autoimmune gastritis can be generated by direct immunization of non-thymectomized BALB/c mice with mouse gastric H+/K(+)-ATPase in complete Freund's adjuvant. The gastritis was characterized by infiltration of the gastric submucosa and mucosa with macrophages, CD4+ and CD8+ T cells, and B cells and by circulating autoantibodies to the H+/K(+)-ATPase. The mononuclear infiltrate within the gastric mucosa was accompanied by loss of parietal and zymogenic cells and accumulation of small immature epithelial cells. Splenocytes from gastritic mice adoptively transferred gastritis to naive recipients. Cessation of immunization resulted in decrease in autoantibody titre and regeneration of parietal and zymogenic cells. The results directly confirm that the gastric H+/K(+)-ATPase is the causative autoantigen in the genesis of autoimmune gastritis. Recovery of the lesion following cessation of immunization suggests that homeostatic mechanisms can reverse a destructive autoimmune process.