title: A mouse model of limbal stem cell deficiency induced by topical medication with the preservative benzalkonium chloride.
abstract: OBJECTIVE
  To develop a mouse model of limbal stem cell deficiency (LSCD) by topical administration of benzalkonium chloride (BAC).
  
  
  METHODS
  BAC solutions (0%-0.5%) were applied to the mouse ocular surface for 4 weeks. Corneal neovascularization, inflammation, and epithelial status were observed under slit-lamp microscope. The eyeball and ocular surface tissues were collected at 4 and 12 weeks and labeled with a series of antibodies. Limbal structure was evaluated by light and transmission electron microscopy (TEM). Corneal impression cytology was performed at 12 weeks, and specimens were labeled with periodic acid Schiff (PAS) reagents.
  
  
  RESULTS
  BAC (0.5%) four times per day for 28 days successfully induced the typical manifestations of LSCD, including corneal neovascularization, severe inflammation in the stroma, and diffuse epithelial defect (P < 0.001). Conjunctival epithelium markers K19 and K13 were positive on the corneal surface. Expression of the putative limbal stem cell markers P63 and ABCG2 was abolished in the limbal epithelium. β-catenin was negative in the basal layer. TEM revealed the irregular basement membrane and the loss of stem cell-specific ultrastructure in the limbal basal epithelium. In the 0.5% BAC group, goblet cells could not be observed on day 28 but emerged after the cessation of BAC, and remained over the cornea after 8 weeks. K13-positive cells were still present over the cornea with the loss of K12.
  
  
  CONCLUSIONS
  Topical administration of BAC at high concentration and frequency in mouse induces ocular surface changes resembling those of LSCD in humans, representing a novel model of LSCD.
authors: Affiliated Xiamen Eye Center and Eye Institute of Xiamen University, Xiamen, People's Republic of China.
authors: Zhirong
authors: Z
authors: Lin
authors: Huan
authors: H
authors: He
authors: Tong
authors: T
authors: Zhou
authors: Xiaochen
authors: X
authors: Liu
authors: Yihui
authors: Y
authors: Wang
authors: Hui
authors: H
authors: He
authors: Huping
authors: H
authors: Wu
authors: Zuguo
authors: Z
authors: Liu
mesh_terms: D000818:Animals; D001548:Benzalkonium Compounds / Q000008:administration & dosage / Q000633:toxicity*; D002478:Cells, Cultured; D003316:Corneal Diseases / Q000139:chemically induced / Q000473:pathology*; D004195:Disease Models, Animal; D016850:Limbus Corneae / Q000187:drug effects / Q000648:ultrastructure*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D046529:Microscopy, Electron, Transmission; D009883:Ophthalmic Solutions; D011310:Preservatives, Pharmaceutical / Q000008:administration & dosage / Q000633:toxicity; D013234:Stem Cells / Q000187:drug effects / Q000648:ultrastructure*
chemical_list: D001548:Benzalkonium Compounds; D009883:Ophthalmic Solutions; D011310:Preservatives, Pharmaceutical
keywords: benzalkonium chloride; goblet cell; inflammation; limbal stem cell deficiency; squamous metaplasia