Carbonic Anhydrases II and IX in Non-ampullary Duodenal Adenomas and Adenocarcinoma

Non-ampullary duodenal adenocarcinoma (DAC) is a rare malignancy. Little information is available concerning the histopathological prognostic factors associated with DAC. Carbonic anhydrases (CAs) are metalloenzymes catalyzing the universal reaction of CO2 hydration. Isozymes CAII, CAIX, and CAXII are associated with prognosis in various cancers. Our aim was to analyze the immunohistochemical expressions of CAII, CAIX, and CAXII in normal duodenal epithelium, duodenal adenomas, and adenocarcinoma and their associations with clinicopathological variables and survival. Our retrospective study included all 27 DACs treated in Oulu University Hospital during years 2000–2020. For comparison, samples of 42 non-ampullary adenomas were collected. CAII expression was low in duodenal adenomas and adenocarcinoma. CAIX expression in adenomas and adenocarcinoma was comparable with the high expression of normal duodenal crypts. Expression patterns in carcinomas were largely not related to clinicopathological features. However, low expression of CAII associated with poorer differentiation of the tumor ( p=0.049) and low expression of CAIX showed a trend for association with nodal spread, although statistical significance was not reached ( p=0.091). CAII and CAIX lost their epithelial polarization and staining intensity in adenomas. CAXII expression was not detected in the studied samples. CAs were not associated with survival. The prognostic value of CAII and CAIX downregulation should be further investigated. Both isozymes may serve as biomarkers of epithelial dysplasia in the duodenum. (J Histochem Cytochem XX: XXX–XXX, XXXX)

Basal-to-classical phenotypic switch of pancreatic cancer cells upon integration into the duodenal epithelium

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive solid tumors. Based on transcriptomic classifiers, basal-like and classical PDAC subtypes can be defined that differ in prognosis. Single-cell sequencing has recently revealed that these subtypes coexist in individual tumors. However, the contribution of either clonal heterogeneity or microenvironmental cues to subtype heterogeneity is unclear. Here, we report the tumor phenotype dynamics in a cohort of patients in whom PDAC infiltrated the duodenal wall. Using multiplex immunohistochemistry, we show that PDAC cells revert to non-destructive growth and undergo differentiation towards the classical subtype upon integration into the duodenal epithelium. Our results tightly link microenvironmental cues to the PDAC molecular subtype and open the door to a systematic investigation of microenvironmental control in human pancreatic cancer.

Immunohistochemical Study of Glucose Transporter GLUT-5 in Duodenal Epithelium in Norm and in T-2 Mycotoxicosis

Although patterns of glucose transporter expression and notes about diseases leading to adaptive changes in intestinal fructose transport have been well-characterized, the connection between infection and fructose transportation has been lightly investigated. Up to now only few studies on GLUT-5 expression and function under pathological conditions in bird intestines have been carried out. The aim of our current research was to immunolocalize GLUT-5 in chicken duodenal epithelium in norm and during T-2 mycotoxicosis. Material from chicken (Gallus gallus domesticus) duodenum was collected from twelve seven-day-old female broilers, divided into control group and broilers with T-2 mycotoxicosis. The material was fixed with 10% formalin and thereafter embedded into paraffin; slices 7 μm in thickness were cut, followed by immunohistochemical staining, according to the manufacturers guidelines (IHC kit, Abcam, UK) using polyclonal primary antibody Rabbit anti-GLUT-5. Our study revealed the strong expression of GLUT-5 in the apical parts of the duodenal epithelial cells in the control group chickens and weak staining for GLUT-5 in the intestinal epithelium in the T-2 mycotoxicosis group. Our results confirmed decreased the expression of GLUT-5 in the duodenal epithelium during T-2 mycotoxicosis.

Immunolocalization of hexose transporters in ostriches' intestinal epithelial cells during their first postnatal week

Although hexoses glucose and fructose serve as important energy sources of food, up to now, there is little information about hexose transporters in birds’ intestinal epithelium during their first postnatal week. The aim of the investigation was to carry out an immunohistochemical study of integral membrane proteins glucose transporter-2 and -5 (GLUT-2 and GLUT-5) on intestinal epithelial cells of ostrich chicks during their first postnatal week. The material from duodenum and ileum was collected from 9 female ostriches (Struthio camelus var. Domesticus) divided into three age groups, three birds in each group: chicks immediately after hatching, 3-day-old ostriches and 7-day-old chicks. The material was fixed in 10% formalin, embedded into paraffin, slices 7μm thick were cut followed by immunohistochemical staining with polyclonal primary antibodies Rabbit anti- GLUT-2 and Rabbit anti-GLUT-5, carried out according to the manufacturer’s guidelines (IHC kit, Abcam, UK). Immunohistochemical localization of GLUT-2 and -5 in the intestinal epithelial cells in ostriches of different age groups was determined. In the groups of chicks after hatching and 3-day-old ostriches, enterocytes in duodenal epithelium were mostly unstained and goblet cells stained weakly for both antibodies. Weak staining of enterocytes and goblet cells was also noted in the ileal epithelium of the chick after hatching. Moderate staining of goblet cells was noted in the 3-day-old chicks’ ileal epithelium. In 7-day-old ostriches, the expression of both antibodies was weak in duodenal but moderate in ileal epithelial cells. The pattern of immunohistochemical expression of GLUT-2 and GLUT-5 in ostriches’ intestinal epithelial cells confirms our hypothesis that the intestinal tract of ostriches after hatching is not yet entirely capable of transportation of hexoses and showed that it is completing gradually during the first postnatal week.

KCa3.1 Transgene Induction in Murine Intestinal Epithelium Causes Duodenal Chyme Accumulation and Impairs Duodenal Contractility

The epithelial intermediate-conductance calcium/calmodulin-regulated KCa3.1 channel is considered to be a regulator of intestine function by controlling chloride secretion and water/salt balance. Yet, little is known about the functional importance of KCa3.1 in the intestinal epithelium in vivo. Our objective was to determine the impact of epithelial-specific inducible overexpression of a KCa3.1 transgene (KCa3.1+) and of inducible suppression (KCa3.1−) on intestinal homeostasis and function in mice. KCa3.1 overexpression in the duodenal epithelium of doxycycline (DOX)-treated KCa3.1+ mice was 40-fold above the control levels. Overexpression caused an inflated duodenum and doubling of the chyme content. Histology showed conserved architecture of crypts, villi, and smooth muscle. Unaltered proliferating cell nuclear antigen (PCNA) immune reactivity and reduced amounts of terminal deoxynucleotide transferase mediated X-dUTP nick end labeling (TUNEL)-positive apoptotic cells in villi indicated lower epithelial turnover. Myography showed a reduction in the frequency of spontaneous propulsive muscle contractions with no change in amplitude. The amount of stool in the colon was increased and the frequency of colonic contractions was reduced in KCa3.1+ animals. Senicapoc treatment prevented the phenotype. Suppression of KCa3.1 in DOX-treated KCa3.1− mice caused no overt intestinal phenotype. In conclusion, inducible KCa3.1 overexpression alters intestinal functions by increasing the chyme content and reducing spontaneous contractions and epithelial apoptosis. Induction of epithelial KCa3.1 can play a mechanistic role in the process of adaptation of the intestine.

Epstein-Barr Virus Association with Peptic Ulcer Disease

Background.Helicobacter pylori(HP) infection and nonsteroidal anti-inflammatory drugs (NSAID) use are considered the main risk to develop peptic ulcer disease (PUD). However, PUD also occurs in the absence ofHPinfection and/or NSAID use. Recently, we have found evidence that Epstein-Barr virus (EBV) reactivation increases the risk to develop premalignant and malignant gastric lesions.Objective. To study a possible association between EBV and PUD.Methods. Antibodies against an EBV reactivation antigen,HP, and theHPvirulence factor CagA were measured in sera from 207 Mexican subjects, controls (healthy individuals,n= 129), and PUD patients (n= 78, 58 duodenal and 20 gastric ulcers). Statistical associations were estimated.Results. Duodenal PUD was significantly associated with high anti-EBV IgG titers (p= 0.022, OR = 2.5), while anti-EBV IgA was positively associated with gastric PUD (p= 0.002, OR = 10.1).Conclusions. Our study suggests that EBV reactivation in gastric and duodenal epithelium increases the risk to develop PUD.

Red kidney bean (Phaseolus vulgaris) lectin stimulation increases the number of enterochromaffin cells in the small intestine of suckling piglets

The quantities and distribution patterns of serotonin-immunoreactive (serotonin-IR) enterochromaffin cells (EC) were studied immunohistochemically in the small intestine of suckling piglets stimulated with red kidney bean lectin, and in nonstimulated, control animals. The co-expression patterns of serotonin with somatostatin (SOM) or corticotropin releasing-factor (CRF) were also studied. After the lectin treatment, the increased numbers of EC were noted in the duodenum of experimental animals. Lectin stimulation did not change the proportions of EC in the jejunum and ileum. In the duodenal epithelium of the lectin-stimulated piglets, the vast majority of serotonin-IR EC were distributed at the basis of crypts. After the lectin administration, the proportions of serotonin-IR/SOM-IR EC were statistically similar in all sections of the small intestine. No upregulation of CRF was found in duodenal, jejunal, and ileal EC of lectin-treated animals. The findings demonstrated that red kidney bean lectin increased the serotonin reservoir in the duodenum, and thus may be an effective stimulant of the gut maturation in suckling mammals.