A multi-site study confirms abnormal glycosylation in the Tamm-Horsfall protein of patients with interstitial cystitis.

Abstract

PURPOSE:

We confirm the single site observation of decreased sialylation and abnormal glycosylation of Tamm-Horsfall protein in patients with interstitial cystitis compared to control subjects.

MATERIALS AND METHODS:

Urine samples from 41 controls and 48 patients with interstitial cystitis from a total of 5 North American sites were obtained in blinded fashion as to participant status. Tamm-Horsfall protein was isolated from urine samples by salt precipitation. Protein content was determined by size exclusion chromatography and normalized to creatinine. Sialic acid was quantified by 1,2-diamino-4,5-methylene dioxybenzene (Sigma®) high performance liquid chromatography with fluorescence detection. Neutral and amino sugars were determined by high pH anion exchange chromatography with pulsed amperometric detection. N-glycans were labeled with 2-aminobenzamide and profiled using high pH anion exchange chromatography with fluorescence detection. Samples were also analyzed by matrix assisted laser desorption/ionization-time of flight mass spectrometry. Permethylated N-glycans were analyzed in the mass-to-charge ratio range of 3,000 to 6,000.

RESULTS:

There was no difference in the protein-to-creatinine ratio of Tamm-Horsfall protein from patients with interstitial cystitis vs controls (49.12 vs 46.4 mg/gm, p = 0.26). Sialic acid content (67 vs 77 nmol/mg Tamm-Horsfall protein, p = 0.025) and total monosaccharide content (590.9 vs 680.6 nmol/mg Tamm-Horsfall protein, p = 0.003) were significantly decreased in patients with interstitial cystitis vs controls. Results were supported by 2-aminobenzamide N-glycan profiling and mass spectrometry, which showed a 45% decrease in a major tetra-sialylated peak (mass-to-charge ratio 4,590) in Tamm-Horsfall protein from patients with interstitial cystitis compared to controls.

CONCLUSIONS:

These multisite data validate that abnormal glycosylation of Tamm-Horsfall protein occurs in patients with interstitial cystitis and may have a role in interstitial cystitis causation.

• Authors: C Lowell Parsons, Jeffrey Proctor, Joel S Teichman, J Curtis Nickel, Edward Davis, Robert Evans, Paul Zupkas, Cody Phillips, Timothy Shaw, Natasha Naidu, Sulabha Argade
• Journal: The Journal of urology (J Urol) Vol. 186 Issue 1 Pg. 112-6 (Jul 2011) ISSN: 1527-3792 [Electronic] United States
• PMID: 21571325 (Publication Type: Journal Article, Multicenter Study)
• Copyright: Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Chemical References

• UMOD protein, human
• Uromodulin

Topics

• Cystitis, Interstitial (metabolism, urine)
• Glycosylation
• Humans
• Uromodulin (metabolism, urine)