Oesophageal damage and defence in reflux oesophagitis: pathophysiological and cell biological mechanisms

Expression of CAIII and Hsp70 Is Increased the Mucous Membrane of the Posterior Commissure in Laryngopharyngeal Reflux Disease

PURPOSE

We tried to evaluate the difference in the expression of carbonic anhydrase (CA) III and heat shock protein (Hsp) 70 between laryngopharyngeal reflux disease (LPRD) and non-LPRD patients.

MATERIALS AND METHODS

The study involved 28 patients who underwent laryngeal microsurgery due to benign laryngeal disease from March to August 2008. Reflux symptom index (RSI) and reflux finding score (RFS) were measured for each person, and they were assigned either to the LPRD group (n=10) or non-LPRD group (n=18). Tissue samples were obtained from the mucosa of posterior commissure, and immunohistochemistry (IHC) staining of CAIII and Hsp70 was performed. The IHC scores were measured and compared with clinical features including RSI and RFS.

RESULTS

Total 10 patients were assigned as LPRD group, and 18 patients were as control group. The mean IHC score of CAIII and Hsp70 was 1.70 ± 1.06 and 1.90 ± 0.88, respectively, in LPRD patients, whereas the mean IHC score of CAIII and Hsp70 was 0.78 ± 0.73 and 0.94 ± 0.87, respectively, in non-LPRD patients. The difference between two groups was statistically significant (p<0.05).

CONCLUSION

CAIII and Hsp70 expressions were higher in LPRD patients that in non-LPRD patients, suggesting the possibility as one of biomomarker in LPRD diagnosis.

Laryngeal epithelial defenses against laryngopharyngeal reflux: investigations of E-cadherin, carbonic anhydrase isoenzyme III, and pepsin

OBJECTIVES

This is the third annual report of an international research network studying the cellular impact of laryngopharyngeal reflux (LPR) on laryngeal epithelium. The objective of this study was to investigate the presence of E-cadherin (epithelial cadherin; the intercellular junctional complex protein) in relation to the presence of (intracellular) pepsin and carbonic anhydrase isoenzyme III (CAIII).

METHODS

Fifty-four laryngeal biopsy specimens from 18 LPR patients were studied by immunohistochemistry and Western blotting for pepsin, E-cadherin, and CAIII. These data were compared to those from normal control subjects analyzed in another research study.

RESULTS

Intracellular pepsin was detected in LPR patients, but not in controls. E-cadherin expression was reduced in patients with LPR. Carbonic anhydrase III expression was not found in the vocal fold or in the majority of samples taken from the ventricle of LPR patients and was inversely associated with E-cadherin membranous expression.

CONCLUSIONS

The findings of depleted E-cadherin and CAIII and the presence of pepsin appear to correlate with LPR. The reduced protective response indicated by the reduced expression of CAIII may play an important role in the disruption of the intercellular barrier associated with the down-regulation of E-cadherin.

Cell biology of laryngeal epithelial defenses in health and disease: further studies

This is the second annual report of an international collaborative research group that is examining the cellular impact of laryngopharyngeal reflux (LPR) on laryngeal epithelium. The results of clinical and experimental studies are presented. Carbonic anhydrase (CA), E-cadherin, and MUC gene expression were analyzed in patients with LPR, in controls, and in an in vitro model. In patients with LPR, we found decreased levels of CAIII in vocal fold epithelium and increased levels in posterior commissure epithelium. The experimental studies confirm that laryngeal CAIII is depleted in response to reflux. Also, cell damage does occur well above pH 4.0. In addition, E-cadherin (transmembrane cell surface molecules, which have a key function in epithelial cell adhesion) was not present in 37% of the LPR laryngeal specimens. In conclusion, the laryngeal epithelium lacks defenses comparable to those in esophageal epithelium, and these differences may contribute to the increased susceptibility of laryngeal epithelium to reflux-related injury.