Histochemistry and Cell Biology

, Volume 125, Issue 5, pp 475–485 | Cite as

Distribution of junction- and differentiation-related proteins in urothelial cells at the leading edge of primary explant outgrowths

  • Mateja Erdani Kreft
  • Maksimiljan Sterle
  • Kristijan Jezernik
Original Paper


Leading edge cells, which are located at the forefront of a wound margin, play a significant role in coordinating the wound healing process. In this study, leading edge cells of the urothelial explant outgrowth, resembling leading edge cells during urothelial full-thickness wound healing in vivo, were analyzed for expression and distribution of junction and differentiation-related proteins. Ultrastructural and immunofluorescence studies revealed that urothelial cells at the leading edge expressed ZO-1, claudin-4, occludin, E-cadherin, cytokeratin 7 and cytokeratin 20, while no expression of claudin-8 was noted. ZO-1, claudin-4, occludin and E-cadherin were localized along the cell membranes where neighbouring leading edge cells were in contact. Cytokeratin 7 was detected as filaments and cytokeratin 20 as small dots and sparse filaments. In conclusion, we detected early expression of ZO-1, claudin-4 and occludin at the urothelial leading edge, predicating the later formation of tight junctions as a necessary stage for the differentiation process that subsequently begins. The expression of occludin and cytokeratin 20 in urothelial cells at the leading edge suggests that leading edge cells may develop into fully differentiated superficial cells.


Leading edge Wound healing Differentiation Cell junctions Urothelium 



The authors thank Dr. Marko Kreft (LN-MCP, Medical Faculty, University of Ljubljana) for work with the confocal microscope. The study was supported by the Slovenian Ministry of Higher Education, Science and Technology (Grant No. Z3-6046-0381-04).


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Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • Mateja Erdani Kreft
    • 1
  • Maksimiljan Sterle
    • 1
  • Kristijan Jezernik
    • 1
  1. 1.Institute of Cell Biology, Medical FacultyUniversity of LjubljanaLjubljanaSlovenia

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