Characterization of the inflammatory infiltrate in peptic oesophagitis

Serotonin disrupts esophageal mucosal integrity: an investigation using a stratified squamous epithelial model

BACKGROUND

Serotonin regulates gastrointestinal function, and mast cells are a potential nonneuronal source of serotonin in the esophagus. Tight junction (TJ) proteins in the esophageal epithelium contribute to the barrier function, and the serotonin signaling pathway may contribute to epithelial leakage in gastroesophageal reflux disease. Therefore, the aim of this study was to investigate the role of serotonin on barrier function, TJ proteins, and related signaling pathways.

METHODS

Normal primary human esophageal epithelial cells were cultured with use of an air-liquid interface system. Serotonin was added to the basolateral compartment, and transepithelial electrical resistance (TEER) was measured. The expression of TJ proteins and serotonin receptor 7 (5-HT₇) was assessed by Western blotting. The involvement of 5-HT₇ was assessed with use of an antagonist and an agonist. The underlying cellular signaling pathways were examined with use of specific blockers.

RESULTS

Serotonin decreased TEER and reduced the expression of TJ proteins ZO-1, occludin, and claudin 1, but not claudin 4. A 5-HT₇ antagonist blocked the serotonin-induced decrease in TEER, and a 5-HT₇ agonist decreased TEER. Inhibition of p38 mitogen-activated protein kinase (MAPK) reduced the serotonin-induced decrease in TEER. Inhibition of p38 MAPK blocked the decrease of ZO-1 levels, whereas extracellular-signal-regulated kinase (ERK) inhibition blocked the decrease in occludin levels. Cell signaling pathway inhibitors had no effect on serotonin-induced alterations in claudin 1 and claudin 4 levels. Serotonin induced phosphorylation of p38 MAPK and ERK, and a 5-HT₇ antagonist partially blocked serotonin-induced phosphorylation of p38 MAPK but not that of ERK.

CONCLUSIONS

Serotonin disrupted esophageal squamous epithelial barrier function by modulating the levels of TJ proteins. Serotonin signaling pathways may mediate the pathogenesis of gastroesophageal reflux disease.

Gastroesophageal reflux in young children and adolescents: Is there a relation between symptom severity and esophageal histological grade?

BACKGROUND

The pediatric literature about the correlation between symptoms and histological lesions in patients investigated for gastroesophageal reflux disease is scarce and inconclusive. The primary aim of the present study was to assess the relation between the complained symptom severity and the esophageal histological grade, through the use of validated and reliable scores.

METHODS

All children ages between 2 and 17 years referred to perform upper gastrointestinal endoscopy because of gastroesophageal reflux disease symptoms were asked to complete the Pediatric Gastroesophageal Symptom and Quality of Life validated questionnaire, investigating the main symptoms complained and their impact on daily life and school activities. Esophageal mucosal samples taken during the procedure were analyzed and scored according to the Yerian-Fiocca classification.

RESULTS

A total of 164 children were included in the study. No significant association was found between symptomatic score and histological score (r(s): 0.05, P: 0.49). Even when focusing only on adolescents with heartburn or chest pain, no correlation between symptom severity and esophageal lesions was found (r(s): -0.18, P: 0.264). Intercellular space diameter values did not mirror symptom severity.

CONCLUSIONS

The main finding of this study on children with reflux symptoms is the lack of correlation between symptom severity and esophageal histological grade. The magnitude of intercellular spaces was found not to be related with the clinical score as well.

Secretory phospholipase A2 inhibition attenuates intercellular adhesion molecule-1 expression in human esophageal adenocarcinoma cells

BACKGROUND

Esophageal adenocarcinoma is an aggressive malignancy, with most patients succumbing to metastatic disease. The presence of intercellular adhesion molecule-1 (ICAM-1) in these cancer cells contributes to their metastatic potential. The ICAM-1 production in other cell types is stimulated by the actions of phospholipase enzymes. We hypothesize that inhibition of the enzyme secretory phospholipase A2 (sPLA2), which contributes to the growth potential of normal esophageal mucosa and esophageal cancer cells, may attenuate ICAM-1 production and nuclear factor-kappa beta activation in human esophageal adenocarcinoma cells.

METHODS

The FLO-1 verified human esophageal adenocarcinoma cells were treated with 5-(4-benzyloxyphenyl)-4S-(7-phenylheptanoylamino) pentanoic acid, a specific inhibitor of group IIa sPLA2 (5 μM, 10 μM, and 15 μM doses), followed by tumor necrosis factor-alpha stimulation (20 ng/mL). Cells and medium were collected and analyzed by immunoblotting, flow cytometry, and enzyme-linked immunosorbent assay. Statistical analysis was performed using analysis of variance with the Fisher's least significant difference post-hoc test.

RESULTS

Treatment with sPLA2 inhibitor attenuated total cellular ICAM-1 expression in a dose-dependent manner (p<0.005). Cell-surface and secreted ICAM-1 expression decreased significantly with sPLA2 inhibitor treatment (p<0.001 and p<0.05, respectively). sPLA2 inhibition attenuated nuclear factor-kappa beta activation dose-dependently (p<0.05).

CONCLUSIONS

Esophageal adenocarcinoma has significant metastatic potential, and inhibiting its metastasis would significantly advance the treatment of this disease. We demonstrate here that treatment of human esophageal adenocarcinoma cells with sPLA2 inhibitor attenuates the expression of ICAM-1, a marker of metastatic potential, and nuclear factor-kappa beta activation, suggesting a common pathway between the two. These findings identify inhibition of sPLA2 as a potential therapeutic target for esophageal adenocarcinoma.

Evidence for neurotrophic factors associating with TRPV1 gene expression in the inflamed human esophagus

BACKGROUND

Transient receptor potential vanilloid-1 (TRPV1) receptor has been implicated in the mechanism of acid induced inflammation in gastro-esophageal reflux disease (GERD). It has been demonstrated that the increase in nerve growth factor (NGF) and glial derived neurotrophic factor (GDNF) was associated with the increased expression of TRPV1. We aimed to determine whether expression of TRPV1 was increased in severe inflamed human esophagus, and to test the hypothesis whether the expression of TRPV1 was mediated by neurotrophic factors such as NGF and GDNF.

METHODS

We compared biopsies taken from the distal esophagus of 15 patients with erosive GERD, 16 asymptomatic patients (AP), and 10 healthy controls. We assessed the biopsies with reverse transcription polymerase chain reaction (RT-PCR) and real-time quantitative polymerase chain reaction (qPCR) for TRPV1, NGF, and GDNF. Immunohistochemical analysis of TRPV1 protein expression was also determined.

KEY RESULTS

Transient receptor potential vanilloid-1 mRNA level and its protein expression were significantly greater in patients with erosive esophagitis than AP (P < 0.001) and healthy controls (P < 0.001). Nerve growth factor and GDNF gene levels in the esophageal mucosa were also significantly increased in patients with erosive esophagitis compared with AP and healthy controls (all P < 0.001). Transient receptor potential vanilloid-1 mRNA correlated well with NGF (r = 0.61, P < 0.001) and GDNF (r = 0.58, P < 0.001).

CONCLUSIONS & INFERENCES

These results support the association of NGF and GDNF in the up-regulation of TRPV1 receptors in patients with erosive esophagitis.

Do eosinophil numbers differentiate eosinophilic esophagitis from gastroesophageal reflux disease?

CONTEXT

Although the healthy esophageal mucosa contains no eosinophils, eosinophilic infiltration is observed in 2 major clinicopathologic settings: gastroesophageal reflux disease (GERD) and eosinophilic esophagitis (EE). The prevalence of EE is increasing in many countries, and this increase seems only partly to be due to a better awareness of the pathology, following the relatively recent description of EE. Gastroesophageal reflux disease and EE represent 2 entities that do not respond to the same treatment modalities and, thus, need to be distinguished. However, diagnostic criteria of EE have been defined arbitrarily, and the more recent articles tend to prove that the overlap with GERD is probably greater than initially believed, leading the authors to advise strict exclusion of GERD before considering the diagnosis of EE.

OBJECTIVES

To provide pathologists with the currently proposed histologic criteria of GERD and EE, to stress the need to combine these criteria with clinical data and endoscopic findings, and to outline the remaining controversies.

DATA SOURCES

This review is based on selected articles identified by a PubMed (US National Library of Medicine, Bethesda, Maryland) search of the literature in English for GERD and EE, a recent review by the American Gastroenterological Association (Bethesda), the Proceedings of the First International Gastrointestinal Eosinophil Research Symposium, and the authors' experience.

CONCLUSION

Proper identification of the etiology of eosinophilic infiltration of the esophagus allows accurate medical or surgical treatment and follow-up. Eosinophilic esophagitis and GERD diagnoses require integration of the histologic findings with the clinical and endoscopic data.

Comparative Multi-Epitope-Ligand-Cartography reveals essential immunological alterations in Barrett's metaplasia and esophageal adenocarcinoma

Background

Barrett's esophagus (BE) is caused by gastroesophageal reflux with consecutive mucosal inflammation, predisposing patients to the development of esophageal adenocarcinoma (EAC). We investigated changes in T cell-related mucosal combinatorial molecular protein patterns in both diseases using the novel Multi-Epitope-Ligand-Cartography, a unique robotic whole-cell imaging technology that simultaneously visualizes dozens of proteins in structurally intact tissues and correlates cellular localization of proteins with function.

Results

Biopsies were taken during endoscopy from BE, EAC, and normal control tissue, and proteomic microscopy was performed on 32 different epitopes. When the significance level was set to p < 0.0005 and the search depth to five antibody combinations, controls and BE can be differentiated by 63, controls and EAC by 3222, and BE from EAC by 1521 distinct protein combinations.

For example, the number of activated apoptotic naïve and memory T cells was significantly increased only in BE, whereas the number of activated apoptotic helper and regulatory T cells was significantly elevated in BE and EAC. In contrast, the number of activated apoptotic cytotoxic T cells was significantly elevated only in EAC. Confirming different pathways in BE and EAC, the number of T lymphocytes with p53 expression and downregulation of bcl2 expression (CD3⁺p53⁺Bcl2^-NfkB^-) was significantly increased in EAC compared to BE and controls. Interestingly, the number of precursor T cells (CD7⁺) was significantly elevated only in EAC. These cells lack Bax and caspase-8, suggesting impaired apoptosis in the early stages of T cell differentiation.

Conclusion

Proteomic analysis showed for the first time that proteins, which are critically involved in the mucosal immune system of the esophagus, are distinctly expressed in BE and EAC, whereas others are comparably altered in both diseases, suggesting that many pathogenic events might be shared by both diseases. Topological proteomic analysis, therefore, helps us to understand the different pathogenic events in the underlying disease pathways.

Direct evidence of mast cell participation in acute acid-induced esophageal inflammation in mice

OBJECTIVES

Mast cells have been implicated in the pathogenesis of esophagitis resulting from gastroesophageal acid reflux, but their precise role has been difficult to define. We proposed to directly examine the contribution of mast cells to neutrophil infiltration in a mouse model of acid-induced esophageal injury.

MATERIALS AND METHODS

Normal and mast cell-deficient (Kit) mice underwent either a surgical procedure to induce acute acid reflux injury of the esophagus or sham surgery. Neutrophil infiltration in the esophagus was determined by morphometrical quantification. To further delineate the involvement of mast cells, acid-induced esophageal injury was elicited in mast cell-deficient mice that had undergone mast cell reconstitution by bone marrow transplantation.

RESULTS

Normal mice exhibited significant neutrophil infiltration into the esophagus as a result of acid-induced injury. The neutrophil accumulation was significantly diminished in mast cell-deficient mice. However, the neutrophil infiltration that resulted from acid-induced injury in mast cell-reconstituted Kit mice was similar to that seen in normal mice.

CONCLUSIONS

Our findings provide direct evidence that mast cells participate in the recruitment of neutrophils during acid-induced esophageal injury in mice.

Reflux oesophagitis in children; the role of endoscopy. A multicentric Italian survey

BACKGROUND

The decision whether to perform endoscopy in children with suspected reflux oesophagitis is not a straightforward one. Few symptoms are specific for oesophagitis and the diagnosis is not always correlated even to visual findings on endoscopy.

AIM

The aim of this study was to define the role of endoscopy and especially of histology in the diagnosis of reflux oesophagitis and to examine the correlations between symptoms, endoscopic findings and histology in children with suspected gastroesophageal reflux disease.

PATIENTS AND METHODS

One hundred and thirty-six patients with a clinical diagnosis of reflux oesophagitis, aged 1-18 years (mean 8.43; standard deviation +/-4.4), were enrolled from 12 Italian Paediatrics Gastroenterology Centres; symptom score, endoscopic and histologic oesophagitis scores were observed before and after therapy with proton pump inhibitors.

RESULTS

Before therapy, a high correlation between the prevailing symptom score and endoscopic score was demonstrated, but not with histologic score: there was a significant tendency for histologic grade to exceed visual findings. After therapy, endoscopic score and histologic score were significantly improved.

CONCLUSIONS

Oesophageal biopsies increase the diagnostic accuracy of upper endoscopy. Histologic grading is often much more important than the endoscopic appearance, so that endoscopic oesophageal biopsies are very important aids in the diagnosis of oesophagitis. Appropriate clinical evaluation of symptoms must occur before endoscopic examination.

Acid challenge to the human esophageal mucosa: effects on epithelial architecture in health and disease

The histological changes that occur in the squamous epithelium in response to acute acid challenge was examined in healthy controls and proton pump inhibitor-treated gastroesophageal reflux disease (GERD) patients and related to the state of untreated erosive GERD in a saline-controlled, randomized perfusion study. In the basal state a stepwise significant increase in the thickness of the basal cell layer, papillary length, and dilatation of intercellular spaces (DIS) was seen when the three groups were compared. Acid perfusion induced a slight increase in the height of the basal cell layer mainly in healthy volunteers; this layer appears to be reactive to acute acid challenge as well as to acid suppressive therapy. DIS increases promptly in response to acute acid exposure in the healthy epithelium but no changes were seen in the lengths of the papillae or regarding DIS in the GERD patients. A protective effect of luminal nitric oxide on DIS development is suggested.

Gastroesophageal reflux disease in infants: how much is predictable with questionnaires, pH-metry, endoscopy and histology?

Symptoms of gastroesophageal reflux disease (GERD) are common in infants. It is often difficult to discriminate between physiological and pathologic gastroesophageal reflux, although this discrimination is essential to determine which infants to evaluate and treat.

OBJECTIVES

To identify the prevalence of reflux symptoms in infants and to evaluate the predictive value of a questionnaire and the correlation between pH study, histology and clinical score.

METHODS

Parents of 100 unselected infants visiting the well-baby clinic and 100 infants suspected of having gastroesophageal reflux disease were asked to fill in a 35-item questionnaire. A validated score, the Orenstein I-GERQ, was applied for selected questions. All infants suspected of having gastroesophageal reflux disease underwent prolonged esophageal pH monitoring and 44 or 100 underwent upper gastrointestinal tract endoscopy with esophageal biopsy.

RESULTS

Parents of infants with suspected gastroesophageal reflux disease reported significantly more regurgitation (68% versus 45%, P < 0.05) and crying (51% versus 20%, P < 0.01) compared with the parents of healthy infants. A pathologic pH study (reflux index > 10%) was found in 21 of 100 (21%) infants and was significantly associated only with pneumonia, apnea with fussing (P = 0.013 for both), defecation less than once a day (P = 0.033) and constipation (P = 0.05). Esophagitis was present in 17 of 44 (39%) and no one question was found to be significantly predictive. 38% of infants with a pathologic pH study had a normal esophageal biopsy and 53% of infants with histologic esophagitis had a normal pH study. Discordance between pH study and biopsies occurred in 14 of 44 (32%) patients. The Orenstein I-GERQ cut-off score failed to identify eight of 31 (26%) infants with gastroesophageal reflux disease. Conversely, the score was positive in 17 of 22 (81%) infants with normal biopsy and pH study and in 14 of 47 (30%) infants with normal pH study.

CONCLUSIONS

Clinical symptoms, histology and pH study show poor correlation in infants. Clinical symptoms such as regurgitation and crying are less frequent in unselected infants than in infants suspected of gastroesophageal reflux disease. However, questionnaires are poorly predictive for the severity of gastroesophageal reflux disease, as they do not correlate with esophageal acid exposure as measured by pH-metry and with esophagitis as evaluated by histology of esophageal biopsies.

Increased capsaicin receptor TRPV1 nerve fibres in the inflamed human oesophagus

BACKGROUND

Gastro-oesophageal reflux disease (GORD) patients commonly describe symptoms of heartburn and chest pain. The capsaicin receptor vanilloid receptor 1 (TRPV1) (VR1) is a cation channel expressed by sensory neurones and activated by heat, acid pH and ethanol, which may trigger burning pain.

AIM

To study the distribution of TRPV1-expressing nerve fibres in oesophageal mucosal biopsies from patients with symptomatic oesophagitis and in control subjects.

METHODS

Biopsies were taken at gastroscopy from the distal oesophagus of seven symptomatic oesophagitis patients and seven asymptomatic patients undergoing investigation for iron-deficiency anaemia. These biopsies were studied by immunohistochemistry using affinity-purified antibodies to TRPV1 and to the neuronal marker peripherin. The density of oesophageal epithelial TRPV1 innervation was assessed by calculating the proportion of papillae in each oesophageal epithelium biopsy specimen containing TRPV1-immunoreactive fibres.

RESULTS

TRPV1-immunoreactive nerves were distributed within the lamina propria in healthy subjects and in oesophagitis patients. The percentage of papillae positive for TRPV1 was elevated in oesophagitis patients compared with controls. Peripherin fibre density was not significantly different between the groups.

CONCLUSIONS

TRPV1-immunoreactive sensory nerve fibres are expressed in human oesophageal mucosa both in health and in disease. Increased TRPV1 expression in the inflamed oesophagus may mediate the heartburn in oesophagitis, and TRPV1 blockers may provide novel treatment.

Histological score for cells with irregular nuclear contours for the diagnosis of reflux esophagitis in children

Histological criteria for the diagnosis of reflux esophagitis include basal zone hyperplasia, stromal papillae elongation, and inflammatory infiltrate. However, endoscopic esophageal biopsy specimens may include little or no lamina propria. Intraepithelial T lymphocytes, seen in hematoxylin and eosin-stained sections as cells with irregular nuclear contours (CINC), may have a higher density in children with esophagitis. We evaluated the diagnostic accuracy of a numerical score built up by grading the "classical" parameters and its correlation with CINC density in grasp biopsy specimens obtained from children undergoing esophagogastroduodenoscopy with and without esophagitis. We analyzed esophageal biopsy specimens from 349 children (median age, 5 years) subdivided in 4 groups according to the previous routine histology report: group 1, 144 children with esophagitis; group 2, 65 controls; group 3, 51 children with dubious esophagitis; and group 4, 75 children with esophagitis on endoscopy but a normal histology report. A numerical value was assigned to each parameter; the sum of these values represented the histological score. We also evaluated intraepithelial CINC density (ie, number of CINC per high-power field). We separately analyzed histological sections with and without lamina propria. For both total score and for CINC density, we calculated a cutoff using a receiver operating characteristic curve. Cutoffs of 6 for score and of 4 for CINC density provided the best sensitivity and specificity. Sensitivity of the histological score was better in biopsy specimens containing lamina propria (94%) than in those without lamina propria (4%). Sensitivity of CINC density was satisfactory in both specimens with (78%) and without (75%) lamina propria. Specificity was satisfactory for both parameters. In conclusion, when lamina propria was present in sections of endoscopic esophageal biopsy specimens, histological score provided a better diagnostic accuracy for the diagnosis of esophagitis. However, when no lamina propria was present, as was the case in 67% of our children, CINC density had better sensitivity. In addition, this latter parameter showed esophageal mucosa damage in 34% of previously dubious cases or cases with esophagitis at endoscopy but a previous routine histology report of normal mucosa.