title: Potential candidate cells for constructing tissue-engineered lacrimal duct epithelium: a histological and cytological study in rabbits.
abstract: OBJECTIVE
  Injury and deficiency of the lacrimal duct epithelium (LDE) can lead to a variety of lacrimal diseases. The purpose of this study was to characterize potential candidate cells for constructing a tissue-engineered LDE.
  
  
  METHODS
  Different areas of the conjunctiva and lacrimal duct tissue were removed from male adult New Zealand white rabbits for histological evaluation. Hematoxylin and eosin staining and immunohistochemical staining of cytokeratin AE1+AE3, cytokeratin 4, Ki-67, and MUC5AC were observed by light microscopy. The surface morphologies of different epithelial tissues and cellular structures were examined using field-emission scanning electron microscopy and transmission electron microscopy. Epithelial cells were isolated from tissues and identified by specific markers. In vitro, proliferative ability and Western blot analyses of the proliferating cell nuclear antigen (PCNA) of different epithelial cells cultured in identical environments were investigated and compared.
  
  
  RESULTS
  Histologically, the epithelial specific markers, cytokeratin AE1+AE3 and cytokeratin 4, were expressed in the conjunctiva epithelium and the LDE. Notably, highly proliferative cells stained with Ki-67 were concentrated under the epithelium in a dome structure of the posterior palpebral conjunctiva. Differentiated goblet cells were also found to a lesser extent in this region. Primary palpebral and fornical conjunctival epithelial cells (PFCECs), bulbar conjunctival epithelial cells (BCECs), and lacrimal duct epithelial cells (LDECs) were successfully separated from tissues. In vitro, rabbit PFCECs and LDECs grew faster and expressed more PCNA than BCECs.
  
  
  CONCLUSIONS
  PFCECs are anatomically similar to LDECs. They also have similar morphological characteristics, immune phenotypes, and proliferation features. PFCECs are therefore potential candidate cells to replace LDECs in tissue engineering to treat lacrimal duct diseases.
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Xie
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China.
authors.forename: Xiu-yi
authors.initials: XY
authors.lastname: Li
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China.
authors.forename: Hong-guang
authors.initials: HG
authors.lastname: Cui
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000166:cytology* / Q000648:ultrastructure; D007150:Immunohistochemistry; D007765:Lacrimal Apparatus / Q000166:cytology* / Q000648:ultrastructure; D008297:Male; D064347:Microscopy, Electrochemical, Scanning; D011817:Rabbits; D023822:Tissue Engineering
keywords: Conjunctival epithelial cells; Cytokeratin; Lacrimal duct epithelial cells; Mucin; Proliferating cell nuclear antigen; Tissue engineering