Role of salivary and seric epidermal growth factor in pathogenesis of reflux esophagitis in chronic alcoholics and nondrinkers

Lack of Association between Epidermal Growth Factor or Its Receptor and Reflux Esophagitis, Barrett’s Esophagus, and Esophageal Adenocarcinoma: A Case-Control Study

The epidermal growth factor (EGF) and its receptor (EGFR) gene-gene interactions were shown to increase the susceptibility to esophageal cancer. However, the role of the EGF/EGFR pathway in the development of gastroesophageal reflux disease (GERD) and its complications (reflux esophagitis (RE), Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC)) remains unclear. This association study is aimed at investigating functional EGF and EGFR gene polymorphisms, their mRNA expression in esophageal tissues, and EGF plasma levels in relation to RE, BE, and EAC development in the Central European population. 301 patients with RE/BE/EAC (cases) as well as 98 patients with nonerosive reflux disease (NERD) and 8 healthy individuals (controls) were genotyped for +61 A>G EGF (rs4444903) and +142285 G>A EGFR (rs2227983) polymorphisms using the TaqMan quantitative polymerase chain reaction (qPCR). In random subgroups, the EGF and EGFR mRNA expressions were analyzed by reverse transcription qPCR in esophageal tissue with and without endoscopically visible pathological changes; and the EGF plasma levels were determined by enzyme-linked immunosorbent assay. None of the genotyped SNPs nor EGF-EGFR genotype interactions were associated with RE, BE, or EAC development (p > 0.05). Moreover, mRNA expression of neither EGF nor EGFR differed between samples of the esophageal tissue with and without endoscopically visible pathology (p > 0.05) nor between samples from patients with different diagnoses, i.e., RE, BE, or EAC (p > 0.05). Nevertheless, the lower EGF mRNA expression in carriers of combined genotypes AA +61 EGF (rs4444903) and GG +142285 EGFR (rs2227983; p < 0.05) suggests a possible direct/indirect effect of EGF-EGFR gene interactions on EGF gene expression. In conclusion, EGF and EGFR gene variants and their mRNA/protein expression were not associated with RE, BE or EAC development in the Central European population.

Stimulated saliva secretion is reduced in proton pump inhibitor-resistant severe reflux esophagitis patients

BACKGROUND

Salivary secretion in patients with proton-pump inhibitor (PPI)-resistant severe reflux esophagitis has not been examined. In this study, saliva secretion and salivary epidermal growth factor (EGF) in patients with PPI-resistant severe reflux esophagitis were investigated.

METHODS

We recruited 22 PPI-resistant and 22 PPI-responsive severe reflux esophagitis patients who were not infected with Helicobacter pylori. Saliva secretion testing and esophageal manometry using high-resolution manometry were performed. Saliva secretion was assessed as follows: each patient chewed sugar-free gum for 3 min prior to endoscopy and the amount and pH of saliva as well as the pH of saliva after acid loading as an index of the acid-buffering capacity were measured. The salivary EGF concentration was assessed by ELISA.

RESULTS

The amount of saliva secreted was significantly lower in the PPI-resistant group than in the PPI-responsive group, with medians (25th-75th percentile) of 3.7 (2.2-6.8) and 4.9 (4.0-7.8) mL, respectively (p = 0.029). Salivary pH was significantly lower in the PPI-resistant group [6.9 (6.7-7.2)] than in the PPI-responsive group [7.2 (7.1-7.4), p = 0.001]. Salivary pH after acid loading was significantly lower in the PPI-resistant group [5.6 (5.3-5.9)] than in the PPI-responsive group [6.4 (6.1-6.5), p = 0.002]. The salivary EGF concentration was significantly higher in the PPI-resistant group [3211.5 (1865.0-4121.5)] than in the PPI-responsive group [1816.0 (1123.5-2792.3), p = 0.041]. No significant differences were observed in the proportion of esophageal motility abnormalities.

CONCLUSION

Stimulated saliva secretion was reduced in PPI-resistant severe reflux esophagitis patients.

Salivary proteome characterization of alcohol and tobacco dependents

BACKGROUND

Alcohol and substances found in tobacco may alter salivary flow and amount of saliva proteins. This study aimed to compare salivary proteins between alcohol dependent smokers and controls.

METHODS

This is a case-control study with men older than 18 years of age, matched by age. The alcohol-dependent group was composed by heavy smokers and alcohol consumers. Unstimulated whole saliva was collected from all subjects. Analysis of digested peptides was performed in mass spectrometer. Data were processed using ProteinLynx GlobalServer software. Results were obtained by searching theHomo sapiens database from the UniProt catalog. The search tool IBI-IMIM was used to identify candidate proteins for biomarkers.

RESULTS

Alcohol-dependent and control groups were composed of nine participants each, with mean age of 36.89 ± 2.57 and 35.78 ± 1.64 years, respectively. 404 salivary proteins were found in both groups; 282 in the alcohol-dependent. Among the 96 proteins presented in both groups, 32 were up-regulated in the alcohol dependents (i.e. "Hemoglobin subunit beta" and "Forkhead box protein P2" were up-regulated at least 10-fold), 23 were down-regulated (i.e. "Statherin" and "RNA-binding protein 25" were down-regulated at least 10-fold), and 41 presented similar expression in both groups. 71 proteins were candidates for biomarkers of disorders 58 presented in alcohol dependents' saliva. The most common disorders were neoplasms, genetic, cardiovascular, metabolic and glandular diseases.

CONCLUSIONS

Salivary protein profile undergoes strong changes in alcohol and tobacco dependents. 34% of salivary proteins present in alcohol and tobacco dependents were present in controls; 14.5% of them were expressed in similar quantity.

Alcohol Disrupts Human Liver Stem/Progenitor Cell Proliferation and Differentiation

OBJECTIVE

Excessive alcohol consumption injures the liver resulting in various liver diseases including liver cirrhosis. Advanced liver disease continues to be a major challenge to human health. Liver stem/progenitor cells (LSPCs) are tissue specific precursors with a distinct capacity of multi-lineage differentiation. These precursor cells may play an important role in the process of tissue injury repair and pathological transition of liver structures. At the present time, knowledge about the effect of alcohol on LSPC function during the development of alcoholic liver disease remains absent. This study was conducted to investigate changes in LSPC activity of proliferation and differentiation following alcohol exposure. The disruption of cell signaling mechanisms underlying alcohol-induced alteration of LSPC activities was also examined.

METHODS

Primary and immortalized human liver stem cells (HL1-1 cells and HL1-hT1 cells, respectively) were cultured in media optimized for cell proliferation and hepatocyte differentiation in the absence and presence of ethanol. Changes in cell morphology, proliferation and differentiation were determined. Functional disruption of cell signaling components following alcohol exposure was examined.

RESULTS

Ethanol exposure suppressed HL1-1 cell growth [as measured by cell 5-bromo-2-deoxyuridine (BrdU) incorporation] mediated by epidermal growth factor (EGF) or EGF plus interleukin-6 (IL-6) in an ethanol dose-dependent manner. Similarly, ethanol inhibited BrdU incorporation into HL1-hT1 cells. Cyclin D1 mRNA expression by HL1-hT1 cells was suppressed when cells were cultured with 50 and 100 mM ethanol. Ethanol exposure induced morphological change of HL1-1 cells toward a myofibroblast-like phenotype. Furthermore, ethanol down-regulated E-cadherin expression while increasing collagen I expression by HL1-1 cells. Ethanol also stimulated Snail transcriptional repressor (Snail) and α-smooth muscle actin (α-SMA) gene expression by HL1-1 cells.

CONCLUSION

These results demonstrate that the direct effect of alcohol on LSPCs is inhibiting their proliferation and promoting mesenchymal transition during their differentiation. Alcohol interrupts LSPC differentiation through interfering Snail signaling.

The effect of pre-storage whole-blood leukocyte reduction on cytokines/chemokines levels in autologous CPDA-1 whole blood

BACKGROUND

In this study, we aimed to investigate the effectiveness of pre-storage leukocyte filtration of autologous blood (AB), especially focusing on the cytokines/chemokines accumulation on blood products.

MATERIALS AND METHODS

After approval of the ethics committee of the University of Tokyo, a total of 26 orthopedic patients, who donated AB prior to surgery after informed consent, were enrolled. The effects of filtration on blood cell counts were analyzed, and the accumulation of cytokines and chemokines were measured on pre- and post-leukoreduced (LR) samples, using the Luminex system. The time-dependent changes of the cytokines/chemokines and the effect of the filtration on their concentration were analyzed, and compared with the normal plasma levels reported in the literature.

RESULTS

LR effectively reduced the number of leukocytes and platelets, without affecting that of red cells. The concentration of most of the cytokines/chemokines analyzed, except the EGF, sCD40-L and sFas-L, decreased time-dependently of storage or did not change in pre-LR samples. However, EGF, sCD40L and sFas-L were significantly reduced by LR. Some, such as IL-8 and RANTES, were also importantly decreased by LR, and others, such as IL-1β and TNF-α, were not significantly affected by LR.

CONCLUSIONS

Leukocyte filtration effectively removes platelets and leukocytes from AB, thus preventing the accumulation of cytokines/chemokines. Since adverse effects due to AB transfusion, although rare, are observed, there is need to consider the implementation of pre-storage leukocyte reduction (PSLR) for AB.

Role of salivary function in patients with globus pharyngeus

BACKGROUND

Our aim was to investigate the prevalence and the clinical role of salivary hypofunction in patients with globus sensation.

METHODS

We conducted a prospective observational study in 340 patients with globus pharyngeus. A standard questionnaire and (99m)Tc-pertechnate salivary scintigraphy were used to evaluate salivary hypofunction, with a full examination from the nasal cavity to the larynx (N = 303). We also investigated the effect of xerostomia management on globus symptoms (N = 252).

RESULTS

The symptom scores for xerostomia were higher in patients with severe globus (p < .05). Objective salivary hypofunction was noted in 57.4% of the patients, based on the reference values from control groups. Globus symptoms were more severe in the subgroup with salivary hypofunction (p = .0447). Conservative management of xerostomia significantly reduced the severity of globus at 1 and 3 months (p = .0002) regardless of salivary function.

CONCLUSIONS

Salivary hypofunction seems to be an aggravating factor in globus pharyngeus, but not a direct cause. Conservative management of xerostomia improves globus symptoms.

Is There a Relationship Between the pH and Volume of Saliva and Esophageal pH-metry Results?

There are several implications in the buffer capacity and in the protective role of saliva in gastroesophageal reflux disease (GERD) and other digestive disorders. The lack of knowledge about the production and quality of saliva and the fact that saliva plays an important role in digestive homeostasis motivated the authors to study the relationship between reflux measured by esophageal pH-metry and the pH and volume of saliva in individuals with GERD and its laryngopharyngeal manifestations (LPR). The study was designed as a randomized clinical trial. The studied population consisted of 39 adults with GERD and LPR confirmed by a positive 24-hour double-probe esophageal pH-metry. Unstimulated whole saliva was collected and its pH and volume were compared to pH-metry results. Patients were divided into four groups according to the number of distal episodes of reflux and two groups according to the presence or absence of proximal reflux. A highly significant difference was found between the groups with distal reflux when comparing salivary volume alone and salivary volume/salivary pH. The same occurred for the presence or absence of proximal reflux. These results suggest a direct correlation between salivary volume and "salivary pH x volume" with the number of distal and proximal episodes of reflux on the esophageal pH-metry. If larger studies confirm this finding, in the future it might be possible to diagnose GERD and LPR through a simple "spit test," avoiding more costly and invasive procedures.

Increased expression of transforming growth factor-alpha and epidermal growth factor receptors in rat chronic reflux esophagitis

BACKGROUND AND AIM

Transforming growth factor-alpha (TGF-alpha), which binds to epidermal growth factor receptors (EGF-R), stimulates esophageal epithelial cell proliferation, enabling rapid repair after mucosal injury. The aim of the present study was to examine epithelial proliferation and dynamics of TGF-alpha and EGF-R gene and protein expression in rat chronic acid reflux esophagitis.

METHODS

Gastric acid reflux esophagitis was induced in Wistar rats by ligating the transitional region between the forestomach and the glandular portion, and by covering the duodenum near the pyloric ring with a small piece of an 18Fr Nélaton catheter. Epithelial cell proliferation was assessed by bromodeoxyuridine (BrdU) uptake. Expression of TGF-alpha and EGF-R mRNA and protein was assessed by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry.

RESULTS

Esophageal lesions were observed in the lower and middle esophagus. Histologically, a significant increase in mucosal thickening with elongation of lamina propria papillae and basal cell hyperplasia was observed. The BrdU labeling index was significantly increased from 2.7 +/- 1.0 in normal mucosa and 2.8 +/- 1.2 in background mucosa adjacent to the esophageal lesion, to 60.3 +/- 32.7 in the lesions of chronic esophagitis. Expression of TGF-alpha and EGF-R mRNA in the esophageal lesion significantly increased compared to those in the control and background tissue, whereas treatment with rabeprazole significantly inhibited increases in TGF-alpha and EGF-R mRNA expression. According to immunohistochemical study, TGF-alpha and EGF-R revealed strong expression in esophageal lesions compared with control and background mucosa. The superficial layer of the esophagus was strongly positive for TGF-alpha and most cells in regions of basal hyperplasia had a positive reaction for EGF-R in the esophagitis lesion.

CONCLUSION

Epithelial proliferation and expression of TGF-alpha and EGF-R were significantly increased in rat chronic reflux esophagitis. Activation of TGF-alpha and EGF-R genes in response to acid reflux may facilitate rapid mucosal healing by stimulating epithelial proliferation. These results suggest that TGF-alpha and EGF-R play crucial roles in rat chronic reflux esophagitis.

Correlação do pH e volume salivares com sintomas laringofaríngeos

Apesar do grande entusiasmo despertado pelo avanço dos conceitos definidores do conjunto sintomático denominado refluxo laringofaríngeo (RLF), ainda é muito difícil, para o otorrinolaringologista, estabelecer com segurança se esta síndrome poderá ser considerada no futuro como uma doença semelhante ao refluxo gastroesofágico¹. A nosso ver, os sinais inflamatórios no segmento laringofaríngeo encontrados em alguns pacientes que apresentam phmetria com presença de pH abaixo de 4 na sonda proximal podem ser mimificados por outras situações que agridem a região, não sendo, portanto, patognomônicos de RLF. As condições de fluxo salivar, seu volume, clearence e alterações das condições eletrolíticas da saliva podem influenciar na capacidade de proteção da mucosa regional. OBJETIVO: Este estudo teve como principal objetivo observar a relação entre os sintomas laringofaríngeos de inflamação e o pH e volume salivares. FORMA DE ESTUDO: Observacional coorte com corte transversal. MATERIAL E MÉTODO: Foram estudados 59 sujeitos com idades variando de 24 a 76 anos, com média 50,5 anos, sendo 44 mulheres e 15 homens. Todos os pacientes responderam a questionário sobre sintomas laringofaríngeos e tiveram sua saliva coletada e seu volume e pH mensurados. RESULTADOS: O volume médio de saliva coletado no total de pacientes foi 4,3 ml, com o mínimo de 1,5 e um máximo de 7,5. O pH médio foi de 7,1, se estendendo de 6 a 8. Do total de sintomas apresentados, 31 pacientes apresentaram disfonia, 39 apresentaram pigarro, 2 dispnéia, 24 halitose, 4 caseo, 4 amigdalite de repetição, 6 problemas dento-gengivais, 9 aftas, 6 xerostomia, 12 glossodínia, 36 globus pharingeus, 2 odinofagia, 16 tosse e 8 disfagia. As diversas correlações entre pH, volume salivar e sintomas foram observadas mostrando, em alguns casos, forte correlação positiva ou negativa. CONCLUSÃO: O pH salivar, na dependência do volume salivar, pode ter forte interferência na sintomatologia faringolaríngea.

Increased expression of epidermal growth factor receptors in basal cell hyperplasia of the oesophagus after acid reflux oesophagitis in rats

BACKGROUND

Epidermal growth factor (EGF), which binds to EGF receptors (EGF-R), stimulates oesophageal epithelial cell proliferation, enabling rapid repair after mucosal injury. In the normal human oesophageal epithelium, EGF-R expression is present and confined to the basal layer.

AIM

To examine histological changes in and dynamics of EGF-R expression during healing after acid reflux oesophagitis in a rat model.

METHODS

Gastric acid reflux oesophagitis was induced in Wistar rats by ligation of the pylorus and the transitional region between the forestomach and the grandular portion for 5 h, followed by release of both ligations. Rats were killed 7 and 14 days after production of oesophagitis to examine macroscopic and histological changes as well as dynamics of EGF-R expression. Epithelial cell proliferation was assessed by bromodeoxyuridine (BrdU) uptake, and expression of EGF-R mRNA and protein by RT-PCR and Western blotting or immunohistochemistry.

RESULTS

Gastric acid reflux induced erosive and ulcerative mucosal lesions in the lower and middle part of the oesophagus. These lesions were healed by 14 days and histologically showed thickening of the oesophageal epithelium from 41.11 +/- 3.09 microm in controls to 142.73 +/- 11.59 microm (P < 0.001) in ligated rats, as well as elongation of papillae and basal cell hyperplasia. The number of BrdU-positive cells among basal cells on day 14 was significantly increased from 7.1 +/- 0.8/field in controls to 30.9 +/- 3.0/field in ligated rats. Expression of EGF-R mRNA and protein was significantly increased on day 14 and most basal cells were immunohistochemically positive in both BrdU and EGF-R staining.

CONCLUSION

Acid reflux-induced oesophageal injury caused basal cell hyperplasia with an increase in cell proliferation and EGF-R expression. Activation of EGF-R gene and protein in response to acid reflux-induced injury may facilitate mucosal healing. These results suggest that epidermal growth factor receptors play a crucial role in healing after acid reflux oesophagitis in rats.

Gastroesophageal reflux disease: New oral findings

OBJECTIVE

The objective of this study was to investigate the effects of gastroesophageal reflux disease (GERD) on dentition, salivary function, and oral mucosa.

STUDY DESIGN

Thirty-one patients with esophagitis underwent medical evaluation, which included taking their medical history, performing both an esophagogastroduodenoscopy and esophagus biopsy, and conducting a stomatologic examination. The latter consisted of an extraoral and intraoral physical examination, saliva tests (flow, buffer capacity, and pH), and biopsy and morphometry of the palatal mucosa, as well as taking a history of the patients' habits. Fourteen healthy volunteers from the same population were used as a control group.

RESULTS

No relationship between GERD and changes in the oral cavity was shown by saliva tests, oral clinical examination, or histopathologic examination of the palatal mucosa. However, morphometric analysis of the palatal epithelium showed a statistically significant difference between the patients with GERD and the control group.

CONCLUSIONS

GERD is associated with microscopic alterations in the palatal mucosa (epithelial atrophy and increased fibroblast number), which are only detected by morphometry.

Saliva and esophageal protection

There has been much interest in recent years in the potential protective role of saliva in the esophagus. Variables such as salivary volume and neutralizing capacity have been studied both during basal conditions and in response to esophageal acid exposure, in healthy subjects and in patients with esophagitis. In addition to its known neutralizing capacity, saliva also contains growth factors. These polypeptides (of which epidermal growth factor has been studied most) have cytoprotective and healing properties in various segments of the gastrointestinal tract. Therefore, a deficiency in one or more of these growth factors might be a contributing factor in the development of gastroesophageal reflux disease (GERD) or its complication, such as Barrett's metaplasia. However, human studies have produced contradictory results regarding salivary growth factor deficiency in such patients. Current methods of investigation make it difficult to assess the importance of saliva in GERD. This may be due in part to the multifactorial nature of the disease and the difficulty in long-term, selective manipulation of salivary function in humans. Given the present data in the literature, it is therefore unknown if saliva plays an important role in esophageal protection.

Role of epidermal growth factor (EGF) in oesophageal mucosal integrity

Oesophageal mucosa has well established protective mechanisms, which operate within pre-epithelial, epithelial and post-epithelial compartments. Since refluxed acid and pepsin always act from the luminal side of the mucosa, protective factors like EGF, operating as a part of pre-epithelial defence, are thought to be pivotal in the maintenance of the integrity of the oesophageal mucosa. The significant contribution of salivary EGF to the quality of the oesophageal mucosal barrier has been demonstrated in an experimental setting and in a clinical scenario. Patients with low salivary EGF levels are predisposed to severe oesophageal damage if they develop gastro-oesophageal reflux and are a high-risk group for development of Barrett's oesophagus. Not only the salivary glands but also the human oesophagus has a profound ability to elaborate and release EGF. Some changes in luminal release of EGF during oesophageal mucosal exposure to intraluminal damaging factors imply its role in the oesophageal protective mechanisms. To exert biological effects within the oesophageal mucosal compartment, EGF requires binding to the ligand-binding domain of its receptor. This process results in receptor dimerisation, autophosphorylation and activation of intracellular signal transduction pathways. EGF receptors are localised on the basolateral and luminal aspect of the mucosal cells playing an important role in fast regeneration of oesophageal epithelium through the high mitotic activity of its proliferative zone. An increase in the rate of salivary EGF secretion during masticatory stimulation suggests its potential therapeutic benefit in the treatment of patients with damaged oesophageal mucosa.