Fig. 2.

The keratocyte lineage is involved in tissue repair post injury but stromal cells in maturing scars (up to 2 months after injury) are not keratocytes. (A) The first strategy was to trace keratocyte lineage after the penetrating stromal injury by first labeling keratocytes with eGFP (doxycycline diet for 1 week) and then creating an injury. (B,C) Cells in the injury were derived from the keratocyte lineage as shown by eGFP expression in repaired/regenerated stroma at 1 month (B) and 3 months (C) post injury. (D) The second strategy was to evaluate the phenotype of cells present within maturing scars after the penetrating stromal injury by feeding mice a doxycycline diet for the last week before harvesting. At 1 and 2 months after the penetrating injury, cells did not express eGFP, suggesting that they were not keratocytes. (E) At 1 month post injury (n=6), cells present in the repaired stroma did not express keratocan. However, keratocytes were noted in the peripheral cornea outside the repaired injury area (eGFP expression shown by asterisks). (F) At 2 months after injury (n=6), cells present in the scar still did not express keratocan. White lines indicate scars. Images are representative of at least three experimental repeats from 16 mice. Epi, epithelium; Str, stroma; Endo, endothelium. Scale bars: 25 µm (B,C, right; E,F).