Lineage development in a patient without goblet, paneth, and enteroendocrine cells: a clue for intestinal epithelial differentiation

Multiple Adenocarcinomas of the Small Bowel in a Patient with Brunner’s Glands Agenesia: A Previously Unreported Association

Adenocarcinoma of the small bowel is rather uncommon and several etio-pathogenic factors have been proposed. We report a case of multiple synchronous adenocarcinomas arising in the non-ampullary duodenum and first tract of the jejunum in a background of Brunner’s glands agenesia, chronic duodenitis, and extensive dysplasia in a 64 year-old woman. To the best of our knowledge such association has not been reported so far.

Intestinal Macrophage Autophagy and its Pharmacological Application in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), comprised of Crohn’s disease (CD) and ulcerative colitis (UC), is a group of chronic inflammatory disorders. IBD is regarded as a severe healthcare problem worldwide, with high morbidity and lethality. So far, despite of numerous studies on this issue, the specific mechanisms of IBD still remain unclarified and ideal treatments are not available for IBD. The intestinal mucosal barrier is vital for maintaining the function of the intestinal self-defensive system. Among all of the components, macrophage is an important one in the intestinal self-defensive system, normally protecting the gut against exotic invasion. However, the over-activation of macrophages in pathological conditions leads to the overwhelming induction of intestinal inflammatory and immune reaction, thus damaging the intestinal functions. Autophagy is an important catabolic mechanism. It has been proven to participate the regulation of various kinds of inflammation- and immune-related disorders via the regulation of inflammation in related cells. Here in this paper, we will review the role and mechanism of intestinal macrophage autophagy in IBD. In addition, several well-studied kinds of agents taking advantage of intestinal macrophage autophagy for the treatment of IBD will also be discussed. We aim to bring novel insights in the development of therapeutic strategies against IBD.

Basal and Infectious Enteritis in Broilers Under the I See Inside Methodology: A Chronological Evaluation

Recently, the inflammation of the intestinal mucosa has been related to many diseases in humans and animals. The concept of Microscopic Enteritis (ME) used in human pathology through the Marsh classification system has no counter-part in veterinary medicine. In poultry science, the I See Inside (ISI) methodology, unlike the current linear measures of villi and crypts, generates possibilities to describe and understand the avian ME. Through specific parameters, graded from 0 to 3, the model links proliferative and/or inflammatory reactions in the intestinal layers to some loss in performance. Herein, two trials were conducted in order to describe the development of ME through the ISI methodology in chickens challenged or not with Eimeria spp. and Clostridium perfringens. In each trial, a total of 64 birds were divided in 2 treatments with 4 replicates containing 8 birds each: non-challenged (NCH) and challenged (CH) through gavage with an Eimeria spp. vaccine at 1 day of age and 10⁸ CFU/mL of Clostridium perfringens administered at 10, 11, and 12 days of age. At 7, 14, 21, and 28 days of age birds were euthanized and samples of ileum and liver were collected for ISI evaluation, cytokines and presence of macrophages, CD4+ and CD8+ cell. The results allowed the description of the avian Microscopic Enteritis and of its two basic components: a basal enteritis (BE) in NCH broilers, over which the infectious enteritis is developed in CH birds. In addition, the chronology of ME translated by the ISI methodology parameters were associated to losses in zootechnical performance.

Function of CSE1L/CAS in the secretion of HT-29 human colorectal cells and its expression in human colon

The secretion of colorectal epithelium is important for maintaining the physiological function of colorectal organ. Herein, we report that cellular apoptosis susceptibility (CAS) (or CSE1L) protein regulates the secretion of HT-29 human colorectal cells. Polarity is essential for directed secretion of substances produced by epithelial cells to the external (luminal) compartment; CAS overexpression induced polarization of HT-29 cells. CAS was punctate stained in the cytoplasm of HT-29 cells, and CAS overexpression increased the translocation of CAS-stained vesicles to the cytoplasm near cell membrane and cell protrusions. CAS overexpression increased the secretion of carcinoembryonic antigen (CEA) and cathepsin D. Immunohistochemistry showed CAS was positively stained in the goblet cells of colon mucosa and cells in the crypts of Lieberkühn of human colon as well as the glands in metastatic colorectal cancer tissue. Our results suggest that CAS regulates the secretion of colorectal cells and may regulate the metastasis of colorectal cancer.

Eimeria vermiformis infection reduces goblet cells by multiplication in the crypt cells of the small intestine of C57BL/6 mice

In the gastrointestinal mucosa, mucus produced by goblet cells plays an important role in the defense against various pathogens. It is well known that some helminth parasites are able to up-regulate goblet cell numbers and alter the mucus components. However, the nature of the interactions between the protozoan parasites and goblet cells is still unclear. To clarify this point, we examined the goblet cell response in the small intestinal epithelium in C57BL/6 mice with Eimeria vermiformis infection. On day 6 post-infection (p.i.), we observed E. vermiformis multiplication followed by their destruction within the epithelium of the crypt. However, this was not observed in the villi. There was no evidence that the parasite destroyed the goblet cells; moreover, the number of goblet cells decreased in association with the development of the endogenous stages of E. vermiformis in the jejunum and ileum, but not in the duodenum. During this time, we observed infiltration into the lamina propria by lymphoid cells, such as plasma cells and lymphocytes with some eosinophils, in addition to villous atrophy. A significant reduction of goblet cell numbers occurred on days 8 and 10 p.i. Starting from day 12 p.i., elimination/termination of E. vermiformis was noted, and there was recovery of the villous epithelium along with regeneration of the crypt and goblet cells. The current study examined the reduction of goblet cells and their possible importance in eimerian infections.

Defensins and cathelicidins in gastrointestinal infections

PURPOSE OF REVIEW

To review recently published studies presenting novel and relevant information on antimicrobial peptides in gastrointestinal infections.

RECENT FINDINGS

Defensins and cathelicidins are important antimicrobial peptides expressed by the gastrointestinal epithelium. Their localization and regulation have been the focus of current research establishing the relevance of these peptides both in counteracting an attack by pathogens as well as in controlling the endogenous bacterial flora. In the small intestine, Paneth cell alpha-defensins maintain a low level of microorganisms and regulate the composition of the bacterial flora. In contrast, a constitutive beta-defensin can be found in nearly all gastrointestinal tissues. Other relevant beta-defensins as well as human cathelicidin are inducible by inflammation or infections. Thus Helicobacter pylori enhances defensin expression in the gastric mucosa and Campylobacter jejuni and Salmonella provoke a similar response in the colon. Other pathogenic bacteria may suppress the antimicrobial peptide response as an escape strategy. Notably, the therapeutic induction of cathelicidins alleviates experimental shigellosis, suggesting a future role of endogenous antibiotics in medical therapy.

SUMMARY

These recent findings together with a better understanding of underlying mechanisms involved in the regulation and biology of antimicrobial peptides will open up new therapeutic avenues to battle infections.

Lysyl oxidase-like 2 expression is increased in colon and esophageal tumors and associated with less differentiated colon tumors

Lysyl oxidase-like 2 (LOXL2) belongs to an amine oxidase family whose members have been implicated in crosslink formation in stromal collagens and elastin, cell motility, and tumor development and progression. We previously demonstrated the association between increased LOXL2 expression and invasive/metastatic behavior in human breast cancer cells and mouse squamous and spindle cell carcinomas, interaction between LOXL2 and SNAIL in epithelial-mesenchymal transition, and localization of the LOXL2 gene to 8p21.2-21.3, within a minimally deleted region in several cancers, including colon and esophagus. In the present study, we analyzed LOXL2 expression in colon and esophageal tumors, and explored methylation as a regulator of LOXL2 expression. Immunohistochemistry using normal tissues demonstrated intracellular localization of LOXL2 in colonic enteroendocrine cells and esophageal squamous cells at the luminal surface, but not in mitotically active cells. Tissue array analysis of 52 colon adenocarcinomas and 50 esophageal squamous cell carcinomas revealed presence of LOXL2 expression in 83 and 92% of the samples, respectively, and a significant association between increased number of LOXL2-expressing cells and less-differentiated colon carcinomas. We determined that the methylation status of the 1150 bp 5' CpG island may contribute to the regulation of the gene. Loss of heterozygosity studies, using a microsatellite within intron 4 of the LOXL2 gene, revealed that loss of LOXL2 was unlikely to play a major role in either colon or esophageal tumors. These results suggest that increased LOXL2 expression in colon and esophageal cancer may contribute to tumor progression.

Paneth cells and the innate immune response

PURPOSE OF REVIEW

To review recently published studies presenting novel and relevant information on Paneth cells and their function.

RECENT FINDINGS

Paneth cells are secretory epithelial cells which are predominantly found in the small-intestinal crypts of Lieberkühn. Their most abundant products are alpha-defensins, which are endogenous antibiotics with activity against gram-negative and gram-positive bacteria, fungi, viruses and protozoa. The differentiation from stem-cell progenitors to Paneth cells is regulated by Wnt signalling via a complex gene programme, terminally including defensins. A disturbance of Paneth-cell differentiation and function may predispose to intestinal infections and appears to be a critical factor in the pathogenesis of ileal Crohn's disease, an inflammatory disease of the intestinal tract.

SUMMARY

It is conceivable that these recent findings together with a better understanding of underlying mechanisms involved in the regulation and biology of Paneth cells will open up new therapeutic avenues for preventing infection as well as for causally treating inflammatory bowel diseases.