Generation of a Functional, Differentiated Porcine Urothelial Tissue In Vitro

Alexander M. Turner, Ramnath Subramaniam, David F. M. Thomas, Jennifer Southgate

Research output: Contribution to journalArticlepeer-review


Background: The primary function of urothelium is to serve as a physical urinary barrier. This function is dependent on features expressed at the molecular level that are acquired during cytodifferentiation. Urothelial cells lose differentiated and functional characteristics when propagated in vitro.

Objective: To investigate methods of inducing molecular and functional differentiation of normal porcine urothelial (NPU) cells in vitro.

Design and Measurements: NPU cells were isolated from normal porcine bladders and propagated in a low-calcium keratinocyte serum-free medium. Effects of 5% fetal bovine serum (FBS) and exogenous calcium were investigated. Molecular differentiation was assessed by immunolabelling for urothelial differentiation-associated proteins (UPIIIa, CK20, ZO-1), and barrier function was assessed by measurement of transepithelial electrical resistance (TER).

Results: NPU cell cultures grew as monolayers in low-calcium, serum-free medium. Supplementation with 5% FBS and/or physiological calcium resulted in stratification into basal, intermediate, and superficial cell zones. Superficial cells were positive for UPIIIa, CK20, and ZO-1. TER measurement showed that NPU cells grown with FBS had significantly enhanced barrier function (6720 +/- 1312 SD) compared with cells grown without FBS (102 34 SD; p < 0.001).

Limitations: importantly, our study demonstrates that expression of differentiation-associated immunohistochernical markers by cultured urothelial cells can be regarded as evidence of only morphological differentiation and does not represent a surrogate marker of function.

Conclusions: We have shown that normal porcine bladder urothelium has many cell biological properties equivalent to normal human urothelium, making it an excellent research substitute for difficult-to-obtain tissue. A differentiated, functional barrier urothelium has been produced from porcine bladder urothelial cells propagated in vitro and displays molecular and functional properties equivalent to native urothelium. This tissue has application in developing tissue-engineered bladders with urinary barrier properties and as a research tool for understanding the relationship between molecular and functional tissue differentiation. (c) 2008 European Association of Urology. Published by Elsevier B.V. All rights reserved

Original languageEnglish
Pages (from-to)1423-1432
Number of pages10
JournalEuropean Urology Supplements
Issue number6
Publication statusPublished - Dec 2008


  • Urothelium
  • Tissue engineering
  • Differentiation
  • Porcine
  • Bladder
  • Cell culture

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