| Summary: | 碩士 === 長庚大學 === 基礎醫學研究所 === 94 === Limbal epithelial stem cells (LSC) are the progenitors of corneal epithelium and are known to locate in the basal layer of the limbal epithelium. During corneal wound repair, limbal epithelial stem cells are stimulated to proliferate and generate new epithelial cells to fill the wound surface. Corneal epithelium is strongly positive with Keratin 3, a marker of the mature keratinocyte. In contrast, limbal epithelial basal cells are positive with p63, Keratin 14 and/or PCNA, the markers of either cell undifferentiation or proliferation. Here we show that in the epithelium of wound-healing cornea, the basal cells are positive with p63, Keratin 14 and PCNA, and are negative with Keratin 3, characteristics of that of the limbal basal cells. In contrast, Keratin 3 is expressed in cells located from suprabasal to superficial layers. Interestingly, immuno- fluorescent staining of serial sections shows that all p63 positive cells are also Keratin 14 and PCNA positive. Similar results were obtained with ex vivo cultured limbus. In vivo wounded corneas were allowed to undergo repair to complete the reepithlization. On day 7th post-wounding, central corneas were excised and explanted on AM to evaluate their growth potential. Central corneal epithelium taken from day 7th post-wounding grew vigorously to form an epithelial outgrowth with a rate that was faster than unwounded limbal tissue. In contrast, central corneas taken from day 30th post-wounding were unable to grow and no epithelial outgrowth was formed. The growth potential of the wound-repaired central cornea is positively correlated with the expressions of p63, Keratin 14 and PCNA. Our results suggest that the expression of p63 is an important indicator for the proliferation of corneal epithelial cells.
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