Mucin Gene Expression in Reflux Laryngeal Mucosa : Histological and In Situ Hybridization Observations

Abstract EN

Objectives/Hypothesis.

To determine if laryngopharyngeal reflux alters mucin gene expression in laryngeal mucosa.

Methods.

In situ hybridization was employed to study the expression of the 8 well-characterised mucin genes MUC1-4, 5AC, 5B, 6, and 7 in reflux laryngeal mucosa from laryngeal ventricles, posterior commissures, and vocal folds compared to control/normal laryngeal mucosa.

Results.

MUC1-5 genes are expressed in normal and reflux laryngeal mucosa.

MUC1, 3 and 4 are expressed in respiratory and squamous mucosa whereas MUC2 and 5AC are expressed in respiratory mucosa only.

MUC3, 4 and 5AC are downregulated in reflux mucosa.

MUC5AC expression is significantly reduced in the 3 mucosal sites and when mucosal type was taken into account, this remains significant in combined laryngeal and ventricular mucosa only.

Conclusions.

MUC3, 4 and 5AC expression is downregulated in laryngopharyngeal reflux.

This may be due to laryngeal mucosal metaplasia and/or alteration of mucin gene expression in the preexisting mucosa.

Altered mucin gene expression might predispose laryngeal mucosa to the damaging effect of reflux.