Location: Children's Nutrition Research CenterTitle: Platelet recruitment promotes keratocyte repopulation following corneal epithelial abrasion in the mouse
|LAM, FONG - Children'S Nutrition Research Center (CNRC)|
|PHILLIPS, JENNY - University Of Houston|
|LANDRY, PAUL - University Of Houston|
|MAGADI, SRI - University Of Houston|
|SMITH, C WAYNE - Children'S Nutrition Research Center (CNRC)|
|RUMBAUT, ROLANDO - Michael Debakey Va Medical Center|
|BURNS, ALAN - University Of Houston|
Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/12/2015
Publication Date: 3/16/2015
Citation: Lam, F.W., Phillips, J., Landry, P., Magadi, S., Smith, C., Rumbaut, R.E., Burns, A.R. 2015. Platelet recruitment promotes keratocyte repopulation following corneal epithelial abrasion in the mouse. PLoS One. 29:3151-3159.
Interpretive Summary: This study in young mice on a normal diet focused on the importance of two types of white blood cells in wound healing of the surface of the eye. The experiments relied on genetic engineering to silence some specific genes that are necessary for the cells to carry out their functions. The results reveal for the first time important molecules that allow the white blood cells to leave the blood and assist in the process of normal repair of wounds to the surface of the eye. This work is important because of recent findings that healing of corneal wounds is delayed in mice fed a high fat diet known to alter the function of these white blood cells.
Technical Abstract: Corneal abrasion not only damages the epithelium but also induces stromal keratocyte death at the site of injury. While a coordinated cascade of inflammatory cell recruitment facilitates epithelial restoration, it is unclear if this cascade is necessary for keratocyte recovery. Since platelet and neutrophil recruitment after corneal abrasion is beneficial to epithelial wound healing, we wanted to determine if these cells play a role in regulating keratocyte repopulation after epithelial abrasion. A 2 mm diameter central epithelial region was removed from the corneas of C57BL/6 wildtype, P-selectin deficient (P-sel-/-), and CD18 hypomorphic (CD18hypo) mice using the Algerbrush II. Corneas were studied at 6h intervals out to 48h post-injury to evaluate platelet and platelet and neutrophil cell numbers; additional corneas were studied at 1, 4, 14, and 28 days post injury to evaluate keratocyte numbers. In wild type mice, epithelial abrasion induced a loss of anterior central keratocytes and keratocyte recovery was rapid and incomplete, reaching ~70% of uninjured baseline values by 4 days post-injury but no further improvement at 28 days post-injury. Consistent with a beneficial role for platelets and platelet and neutrophils in wound healing, keratocyte recovery was significantly depressed at 4 days post-injury (~30% of uninjured baseline) in P-sel-/- mice, which are known to have impaired platelet and platelet and neutrophil recruitment after corneal abrasion. Passive transfer of platelets from wild type, but not P-sel-/-, into P-sel-/- mice prior to injury restored anterior central keratocyte numbers at 4 days post-injury to P-sel-/- uninjured baseline levels. While platelet and neutrophil infiltration in injured CD18hypo mice was similar to injured wild type mice, platelet recruitment was markedly decreased and anterior central keratocyte recovery was significantly reduced (~50% of baseline) at 4-28 days post-injury. Collectively, the data suggest platelets and platelet P-selectin are critical for efficient keratocyte recovery after corneal epithelial abrasion.