Significance of paneth cell metaplasia in Barrett esophagus: a morphologic and clinicopathologic study

Interleukin-9 production by type 2 innate lymphoid cells induces Paneth cell metaplasia and small intestinal remodeling

Paneth cell metaplasia (PCM) typically arises in pre-existing gastrointestinal (GI) diseases; however, the mechanistic pathway that induces metaplasia and whether PCM is initiated exclusively by disorders intrinsic to the GI tract is not well known. Here, we describe the development of PCM in a murine model of chronic myelogenous leukemia (CML) that is driven by an inducible bcr-abl oncogene. Mechanistically, CML induces a proinflammatory state within the GI tract that results in the production of epithelial-derived IL-33. The binding of IL-33 to the decoy receptor ST2 leads to IL-9 production by type 2 innate lymphoid cells (ILC2) which is directly responsible for the induction of PCM in the colon and tissue remodeling in the small intestines, characterized by goblet and tuft cell hyperplasia along with expansion of mucosal mast cells. Thus, we demonstrate that an extra-intestinal disease can trigger an ILC2/IL-9 immune circuit, which induces PCM and regulates epithelial cell fate decisions in the GI tract.

Paneth cell development in the neonatal gut: pathway regulation, development, and relevance to necrotizing enterocolitis

Paneth cells (PCs) are intestinal epithelial cells (IECs) that contain eosinophilic granules, which are located in Lieberkühn crypts. An increasing number of animal and human experiments have indicated that PCs are involved in the progression of a variety of intestinal as well as systemic inflammatory responses including necrotizing enterocolitis (NEC). NEC is an enteric acquired disease with high mortality that usually occurs in premature infants and neonates, however the underlying mechanisms remain unclear. In this review, we summarize the features of PCs, including their immune function, association with gut microbiota and intestinal stem cells, and their mechanism of regulating IEC death to explore the possible mechanisms by which PCs affect NEC.

Mechanisms and pathophysiology of Barrett oesophagus

Barrett oesophagus, in which a metaplastic columnar mucosa that can predispose individuals to cancer development lines a portion of the distal oesophagus, is the only known precursor of oesophageal adenocarcinoma, the incidence of which has increased profoundly over the past several decades. Most evidence suggests that Barrett oesophagus develops from progenitor cells at the oesophagogastric junction that proliferate and undergo epithelial-mesenchymal transition as part of a wound-healing process that replaces oesophageal squamous epithelium damaged by gastroesophageal reflux disease (GERD). GERD also seems to induce reprogramming of key transcription factors in the progenitor cells, resulting in the development of the specialized intestinal metaplasia that is characteristic of Barrett oesophagus, probably through an intermediate step of metaplasia to cardiac mucosa. Genome-wide association studies suggest that patients with GERD who develop Barrett oesophagus might have an inherited predisposition to oesophageal metaplasia and that there is a shared genetic susceptibility to Barrett oesophagus and to several of its risk factors (such as GERD, obesity and cigarette smoking). In this Review, we discuss the mechanisms, pathophysiology, genetic predisposition and cells of origin of Barrett oesophagus, and opine on the clinical implications and future research directions.

[Paneth Cell Carcinoma of the Stomach]

Paneth cell carcinoma is a rare carcinoma composed predominantly or purely of malignant Paneth cells. An 83-year-old woman presented for evaluation of an elevated lesion in the stomach. On endoscopy, a 15 mm, discolored, elevated lesion with a central depression was found on the greater curvature of the gastric lower body. Endoscopic forceps biopsy revealed chronic gastritis with intestinal metaplasia. Magnifying endoscopy revealed an irregularly oval/tubular microsurface pattern and an irregular loop microvascular pattern with a demarcation line, suggestive of early gastric cancer. Therefore, endoscopic submucosal dissection was performed. Histopathological examination revealed a well-differentiated tubular adenocarcinoma limited to the muscularis mucosae and the tumor cells contained coarse eosinophilic granules in the cytoplasm. These tumor cells were diffusely and strongly stained for lysozyme, confirming the tumor diagnosis as Paneth cell carcinoma. Herein, we report a rare case of Paneth cell carcinoma and its endoscopic and histopathologic findings.

Differences in Regression Patterns of Complete and Incomplete Intestinal Metaplasia at Ten Years after Helicobacter pylori Eradication

This study was conducted to reveal the reversibility of subtype of intestinal metaplasia (IM) and Paneth cells after H. pylori eradication (HPE). Among 75 patients, we retrospectively examined the proportions of patients with complete type of IM (CIM), incomplete type of IM (IIM) and Paneth cells in their biopsy specimens obtained from the greater curvature of the antrum (A2) and the greater curvature of the middle corpus (B2) before and during a follow-up period of 10 years after HPE. Immunohistochemistry was used to determine IM type. Compared to before HPE, the proportion of patients with CIM did not decrease significantly during the 10-year follow-up after HPE both in A2 (32% vs. 21.3%, P = 0.13) and in B2 (6.7% vs. 2.7%, P = 0.60). IIM rates in A2 was significantly lower during this time (26.7% vs. 10.7%, P = 0.04), whereas no patients showed IIM in B2 before HPE. The proportion of patients with Paneth cells decreased significantly in A2 after 3, 8, and 9 years of HPE and in B2 after 4, 6 and 9 years of HPE (P < 0.05 for all). Thus, IIM and Paneth cells regressed during a period of 10 years after HPE.

Secretory Sorcery: Paneth Cell Control of Intestinal Repair and Homeostasis

Paneth cells are professional secretory cells that classically play a role in the innate immune system by secreting antimicrobial factors into the lumen to control enteric bacteria. In this role, Paneth cells are able to sense cues from luminal bacteria and respond by changing production of these factors to protect the epithelial barrier. Paneth cells rely on autophagy to regulate their secretory capability and capacity. Disruption of this pathway through mutation of genes, such as Atg16L1, results in decreased Paneth cell function, dysregulated enteric microbiota, decreased barrier integrity, and increased risk of diseases such as Crohn's disease in humans. Upon differentiation Paneth cells migrate downward and intercalate among active intestinal stem cells at the base of small intestinal crypts. This localization puts them in a unique position to interact with active intestinal stem cells, and recent work shows that Paneth cells play a critical role in influencing the intestinal stem cell niche. This review discusses the numerous ways Paneth cells can influence intestinal stem cells and their niche. We also highlight the ways in which Paneth cells can alter cells and other organ systems.

Metaplastic Paneth Cells in Extra-Intestinal Mucosal Niche Indicate a Link to Microbiome and Inflammation

Paneth cells are residents of the intestinal epithelium. Abnormal appearance of Paneth cells has been widely documented in non-intestinal tissues within the digestive tract and even observed in non-gastrointestinal organs. Although metaplastic Paneth cells are part of the overarching pathology of intestinal metaplasia (IM), only a fraction of intestinal metaplastic lesions contain Paneth cells. We survey literature documenting metaplastic Paneth cells to gain insights into mechanism underlying their etiologic development as well as their potential relevance to human health. A synthesized view from this study suggests that the emergence of metaplastic Paneth cells at extra-intestinal mucosal sites likely represents a protective, anti-bacterial, and inflammatory response evoked by an altered microbial activity.

Gastroesophageal junction Paneth cell carcinoma with extensive cystic and secretory features - case report and literature review

Background

Carcinomas composed predominantly or purely of malignant Paneth cells were rarely reported in gastrointestinal system. They have not been reported at gastroesophageal junction nor has the association with Barrett esophagus been explored. None of the previous studies has mentioned any peculiar histologic features other than typical adenocarcinoma containing neoplastic Paneth cells. The Her2/neu status and the expression of beta-catenin in Paneth cell carcinoma at gastroesophageal junction have not been studied although the activated beta-catenin pathway was recently demonstrated in neoplastic Paneth cells in colon.

Case presentation

A 70-year-old Caucasian male who initially presented in the emergency room due to upper gastrointestinal bleeding was subsequently found to have a submucosal nodule at gastroesophageal junction. A diagnosis of adenocarcinoma was rendered on biopsy. Histologic examination of the subsequent endoscopic mucosal resection revealed an adenocarcinoma with various levels of differentiation which are zonally distributed. The deeper portion of the tumor showed well-differentiated bland-appearing glands with extensive cystic and secretory changes. The cytoplasm of tumor cells and secretion demonstrated marked reactivity with lysozyme antibody on immunohistochemical stain. The tumor had a peculiar Her2/neu staining pattern with cytoplasmic and nuclear stain in poorly-differentiated area and no stain in well-differentiated area. Only membranous stain was detected with beta-catenin antibody.

Conclusion

We reported the first case of Paneth cell carcinoma at gastroesophageal junction. The tumor had well-differentiated area which, when sampled in small biopsies, can mimic benign lesions including those related to proton pump inhibitor therapy. Lysozyme immunohistochemical stain may be helpful when difficulty in diagnosis arises. Her-2/neu was negative but showed a distinct staining pattern. In contrast to neoplastic Paneth cells in colon, beta-catenin pathway did not seem to be activated. More studies are needed for the etiology, pathogenesis, clinical course, prognosis and treatment of Paneth cell carcinoma.

Extensive Paneth cell metaplasia in an ovarian Krukenberg tumor: report of an unusual case and literature review

Paneth cells are classified as secretory cells which are normally found in the cecum and ascending colon. Their presence in other parts of the gastrointestinal tract is regarded as abnormal and indicates metaplasia. Paneth cells may also be rarely found in gastrointestinal, biliary and prostatic tumors. The presence of Paneth cells in ovarian Krukenberg tumors is rare and to the best of our knowledge is restricted to metastatic appendiceal goblet cells tumors. We report a rare case of unilateral metastatic gastric carcinoma to the ovary in a 23-year-old female. This tumor showed unusual extensive Paneth cells metaplasia with classical signet ring cell morphology.

Paneth cells in intestinal physiology and pathophysiology

Small intestinal mucosa is characterised by villus forming connective tissues with highly specialised surface lining epithelial cells essentially contributing to the establishment of the intestinal border. In order to perform these diverse functions, spatially distinct compartments of epithelial differentiation are found along the crypt-villus axis, including Paneth cells as a highly specialised cell type. Paneth cells locate in crypts and assist undifferentiated columnar cells, called crypt base columnar cells, and rapidly amplifying cells in the regeneration of absorptive and secretory cell types. There is some evidence that Paneth cells are involved in the configuration and function of the stem cell zone as well as intestinal morphogenesis and crypt fission. However, the flow of Paneth cells to crypt bottoms requires strong Wnt signalling guided by EphB3 and partially antagonised by Notch. In addition, mature Paneth cells are essential for the production and secretion of antimicrobial peptides including α-defensins/cryptdins. These antimicrobials are physiologically involved in shaping the composition of the microbiome. The autophagy related 16-like 1 (ATG16L1) is a genetic risk factor and is involved in the exocytosis pathway of Paneth cells as well as a linker molecule to PPAR signalling and lipid metabolism. There is evidence that injuries of Paneth cells are involved in the etiopathogenesis of different intestinal diseases. The review provides an overview of the key points of Paneth cell activities in intestinal physiology and pathophysiology.