Direct visualization of a stratified epithelium reveals that wounds heal by unified sliding of cell sheets.
Observing cells in their original niche is a key link between the information gleaned from planar culture and in vivo physiology and pathology. A new approach combining the transparency of the cornea, Hoffman modulation optics, and digital imaging allowed movements of individual corneal cells to be viewed directly in situ. 3-Dimensional time-lapse movies imaging unstained cells within the stratified corneal epithelium during wound healing were made. Tracking cell movements dynamically provided a definitive answer to the long-standing question: does a stratified epithelium heal by "sliding" of cell sheets as a coherent unit or do individual cells "leap frog" each other at the wound margin? A wound in the corneal epithelium healed primarily by sliding of the whole epithelium, with approximately 95% of cells moving with similar speed and trajectories and with little change in their relative position. Only 5% of cells changed layers, with equal proportions moving up or down. Epithelial healing in situ occurred in three phases: a latency, migration, and reconstruction phase. This model provides a unique system to study the behaviors of individual cells in their original niche. It shows that cells slide into a wound as a unified unit to heal a stratified epithelium.
Zhao
Min
M
Department of Biomedical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK. m.zhao@abdn.ac.uk
Song
Bing
B
Pu
Jin
J
Forrester
John V
JV
McCaig
Colin D
CD
D000818:Animals; D002417:Cattle; D002465:Cell Movement; D002478:Cells, Cultured; D019573:Epithelium, Corneal / Q000166:cytology* / Q000502:physiology*; D006801:Humans; D051379:Mice; D008954:Models, Biological; D009924:Organ Culture Techniques; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D017154:Stromal Cells / Q000502:physiology; D014945:Wound Healing