The Pathogenesis of Duodenal Gastric Metaplasia: the Role of Local Goblet Cell Transformation Gut: First Published As 10.1136/Gut.46.5.632 on 1 May 2000
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632 Gut 2000;46:632–638 The pathogenesis of duodenal gastric metaplasia: the role of local goblet cell transformation Gut: first published as 10.1136/gut.46.5.632 on 1 May 2000. Downloaded from R Shaoul, P Marcon, Y Okada, E Cutz, G Forstner Abstract Gastric metaplasia is characterised by the Background and aims—Gastric metapla- appearance of clusters of epithelial cells of gas- sia is frequently seen in biopsies of the tric phenotype in non-gastric epithelium and duodenal cap, particularly when inflamed may occur anywhere in the intestine and colon. or ulcerated. In its initial manifestation In the duodenum it is found in a small small patches of gastric foveolar cells percentage of otherwise normal biopsies1 but is appear near the tip of a villus. These cells much more frequently seen in association with contain periodic acid-SchiV (PAS) posi- inflammation.2–4 During the past decade the tive neutral mucins in contrast with the frequent association of duodenal gastric meta- alcian blue (AB) positive acidic mucins plasia with Helicobacter pylori gastritis has been 5–9 within duodenal goblet cells. Previous recognised and its potential importance investigations have suggested that these highlighted as a possible starting site for peptic 5 PAS positive cells originate either in ulceration. Gastric metaplasia has also been Brunner’s gland ducts or at the base of reported in Crohn’s disease of the duodenum10–12 and non-specific chronic duodenal crypts and migrate in distinct 23612 streams to the upper villus. To investigate duodenitis. the origin of gastric metaplasia in superfi- In the small intestine the earliest manifesta- cial patches, we used the PAS/AB stain to tion usually occurs as a small island of transformed epithelium on the tip or side of a distinguish between neutral and acidic 513 mucins and in addition specific antibodies villous. Metaplastic cells resemble the super- to immunolocalise foveolar cell mucin ficial gastric mucous secreting cell of the antral and gastric pits or foveoli.9 14–16 These cells con- MUC5AC, the foveolar cell secretory tain a periodic acid-SchiV (PAS) neutral mucin product, gastric trefoil factor (TFF1), the which contrasts with the alcian blue positive mature goblet cell mucin MUC2, and acidic mucins elaborated by intestinal goblet MUC2 core antigen. cells. The superficial origin of these cells Results—Cells in focal patches of gastric http://gut.bmj.com/ suggests that they might originate by local metaplasia contained secretory granules transformation of neighbouring cells. Liu and of both gastric and goblet cell phenotypes. Wright,16 however, described tight cohorts or Division of MUC5AC and TFF1 were present as Gastroenterology and migration streams of PAS positive cells that Nutrition, Hospital for expected in gastric foveolar cells but in appeared to be derived from Brunner’s gland Sick Children, addition, MUC2 core antigen, normally duct epithelium or from basal buds beginning Departments of present only in the Golgi of intestinal gob- in the crypts of Lieberkühn. Evidence from the Paediatrics and let cells, was expressed in secretory gran- Pathology, University same laboratory, indicating that gastric trefoil on September 30, 2021 by guest. Protected copyright. ules. Goblet cells in the vicinity of 17 18 of Toronto, Toronto, factor (TFF1, formerly pS2) protein and Ontario, Canada metaplastic patches also expressed both mRNA18 were expressed in both gastric meta- P Marcon gastric and intestinal antigens. MUC5AC/ plasia and Brunner’s duct cells also suggested E Cutz MUC2 containing goblet cells were most that metaplastic cells might originate in Brun- G Forstner common near the villus tip but were also ner’s gland ducts. Rio and colleagues19 found seen at the base of crypts. Where crypts Department of no evidence, however, that Brunner’s gland Pediatrics, B’nai Zion and Brunner’s gland ducts merged they elements expressed immunoreactive TFF1 Medical Center, Haifa, were always seen on the crypt side of the protein or mRNA. In any case Brunner’s Israel junction. Goblet cells were the only cells to glands are not essential as gastric metaplasia R Shaoul express gastric antigens in these areas. In clearly develops in areas of the intestine that advanced metaplastic lesions, dual pheno- lack them. In these areas Wright and Department of type goblet cells were less evident and 12 20 21 Nutritional Science, colleagues have provided evidence that Faculty of Health and fewer cells expressed intestinal mucin gastric metaplasia originates in a novel PAS Welfare Science, antigens. positive cell line, the so called ulcer associated Okayama Perfectural Conclusions—We suggest that goblet cells cell lineage (UACL) that buds from the base of University, Soja, that express both intestinal and gastric a regenerating crypt and migrates as an Okayama, Japan antigens may represent local precursors of elongating tube through the lamina propria Y Okada gastric metaplasia undergoing a transition until it reaches and fuses with the surface epi- Correspondence to: to foveolar-like cells of mixed phenotype at thelium. Dr G G Forstner, Division of the site of early metaplastic patches. As In the present study we have examined the Gastroenterology and Nutrition, The Hospital for metaplasia becomes more widespread, a origin of superficial gastric metaplasia in the Sick Children, 555 more pure gastric phenotype emerges. duodenum using histochemistry and immuno- University Avenue, Toronto, This progression is likely to be controlled histochemistry to detect gastric and intestinal Ontario, M5G 1X8, Canada email: [email protected] by local inflammatory signals. (Gut 2000;46:632–638) Abbreviations used in this paper: PAS, periodic Accepted for publication acid-SchiV; AB, alcian blue; TFF1, gastric trefoil 20 October 1999 Keywords: gastric metaplasia; goblet cells; mucin factor; UACL, ulcer associated cell lineage. Pathogenesis of duodenal gastric metaplasia 633 mucins as well as TFF1, paying particular Results attention to focal lesions and junctional areas Antibodies to the gastric mucin MUC5AC and between crypts and Brunner’s glands. We TFF1 were used to identify cells with a gastric present evidence that suggests that transforma- phenotype. MUC5AC was localised to the Gut: first published as 10.1136/gut.46.5.632 on 1 May 2000. Downloaded from tion of local intestinal goblet cells to a gastric mucous secreting cells of the upper segment phenotype may be the initial event leading to and surface of the glands of the gastric antrum the appearance of metaplasia. (fig 1A) and was not ordinarily present in the mucous secreting goblet cells of the duodenum (fig 1B). TFF1 was confined to cells that con- Methods tained MUC5AC in the normal antrum but We studied biopsies from 18 patients with was present in more superficial cells (fig 1C). duodenitis (non-specific (n=3), associated with Figure 1D shows a goblet cell on a normal Helicobacter pylori (n=7), or Crohn’s disease duodenal villous with granules that are weakly (n=8)) and 10 age matched normal controls stained for TFF1. This cell was MUC5AC (ages 8–18 years), obtained from our histology negative. In general very few goblet cells in the archives. Biopsies were fixed in 10% formalin, normal duodenum were TFF1 positive. embedded in paraYn, and stained with haema- When gastric metaplasia was localised to toxylin and eosin and PAS/alcian blue (PAS/ segmental areas of duodenal biopsies it was AB). Antigen retrieval was achieved by micro- found in superficial areas of the villus. Cells in waving sections on slides22 in 0.01 mol/l these areas were strongly MUC5AC positive sodium citrate, pH 6.0, standardised for the (fig 1E). TFF1 was expressed in MUC5AC microwave in our pathology laboratory.23 containing cells in metaplastic areas (fig 1F, Immunostaining utilised antibodies raised arrows) but, as in the normal antrum, was lim- against MUC2 core (Novocastra Lab. Ltd, ited to fewer and more superficial metaplastic Newcastle upon Tyne, UK), glycosylated cells. Areas of gastric metaplasia contained MUC2,24 MUC5AC,25 and TFF1,26 and was cells with apical mucous granules that stained performed using an indirect immunoperoxi- an intense red with the PAS/AB stain (fig 1G, dase method.27 In brief, endogenous peroxi- arrowhead) in contrast with the bluish purple dase was blocked with 3% H2O2 for 15 AB positive colour of neighbouring duodenal minutes. The sections were blocked with 5% goblet cells. In fig 1G, PAS positive staining is normal goat serum (Vector Labs., Burlingame, also present in metaplastic cells in a tangen- California, USA) and then incubated with the tially sectioned upper crypt zone (arrow). A primary antibody for one hour at room serial section of the same biopsy (fig 1H) temperature. In control sections, incubation stained with MUC5AC antibody shows that with the primary antibody was omitted. The these PAS positive cells express MUC5AC slides were then washed three times with PBS- (arrows). In addition, fig 1H shows that many http://gut.bmj.com/ BSA, incubated for 45 minutes at room of the AB positive goblet cells in the surround- temperature with biotinylated goat antirabbit ing area are positively stained for MUC5AC. IgG (Molecular Probes, Eugene, Oregon, Some of these goblet cells also expressed USA) for glycosylated MUC2, or donkey anti- TFF1. mouse IgG (Jackson ImmunoResearch Labs., In spite of the positive staining for West Grove, Pennsylvania, USA) for MUC2 MUC5AC and TFF1, goblet cells near meta- core, MUC5AC, and TFF1, washed three plastic zones were alcian blue positive, suggest- times as above, and then incubated with avidin ing that they must also contain significant on September 30, 2021 by guest. Protected copyright. peroxidase (Molecular Probes, Eugene, Or- amounts of intestinal mucin. To confirm this egon, USA) for 45 minutes at room tempera- we studied the distribution of MUC2, the ture, followed by three final washes in Tris principal intestinal mucin, using an antibody buVered saline.