Mucin gene expression in bile of patients with and without gallstone disease, collected by endoscopic retrograde cholangiography

Abstract

To investigate the pattern of mucin expression and concentration in bile obtained during endoscopic retrograde cholangiography (ERC) in relation to gallstone disease. Bile samples obtained at ERC from 29 consecutive patients, 17 with and 12 without gallstone disease were evaluated for mucin content by gel filtration on a Sepharose CL-4B column. Dot blot analysis for bile mucin apoproteins was performed with antibodies to Mucin 1 (MUC1), MUC2, MUC3, MUC5AC, MUC5B and MUC6. Staining intensity score (0-3) was used as a measure of antigen expression. MUC1, MUC2, MUC3, MUC5AC, MUC5B and MUC6 were demonstrated in 34.4%, 34.4%, 51.7%, 51.7%, 55.1% and 27.5% of bile samples, respectively. The staining intensity scores were 0.62 +/- 0.94, 0.58 +/- 0.90, 0.79 +/- 0.97, 1.06 +/- 1.22, 1.20 +/- 1.26 and 0.41 +/- 0.73, respectively. Mean mucin concentration measured in bile by the Sepharose CL-4B method was 22.8 +/- 24.0 mg/mL (range 3.4-89.0 mg/mL). Mean protein concentration was 8.1 +/- 4.8 mg/mL (range 1.7-23.2 mg/mL). High levels of MUC3, MUC5AC and MUC5B are expressed in bile aspirated during ERC examination. A specific pattern of mucin gene expression or change in mucin concentration was not found in gallstone disease.