Purchase this article with an account.
Rachel Sartaj, Aihong Liu, Elaine Fuchs, Mark Rosenblatt; Sox9, a determinant of hair follicle stemness, identifies a subset of murine basal corneal epithelial cells expressing putative stem cell markers. Invest. Ophthalmol. Vis. Sci. 2013;54(15):1000.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To localize the expression of Sox9 in the cornea and to identify genes co-expressed with this determinant of hair follicle stemness.
Antibodies against Sox9 were used to immunostain corneal sections from wild-type mice, and the nuclear localization of Sox9 determined by wide field and confocal microscopy. Localization of Sox9 within the cornea epithelium was confirmed by immunostaining for GFP in Sox9-eGFP mice expressing GFP under the control of the sox9 promoter region. Corneal epithelial cells were isolated from Sox9-egfp mice via sequential enzymatic treatments, and the cell suspension used for FACS sorting to obtain purified population of Sox9-expressing (GFP +) cells and Sox9 non-expressing (GFP-) cells. RNA was separately isolated from GFP + and GFP - populations and qRT-PCR performed to determine the relative expression of putative corneal epithelial stem cell markers ABCG2, p63 and N-cadherin (Cdh2) as well as the differentiation markers keratin-12 (Krt12) and involucrin (Ivl).
In the mouse cornea, Sox9 and GFP proteins were located in the basal cells of central and limbal cornea epithelium in postnatal day 12 (P12) and adult mice (P70). The expression of Sox9 and GFP proteins are restricted to the basal layer of the corneal epithelium at P12 and increases to 2 layers as the Sox9 progeny divides from the basal layer to one row above. Quantitative PCR experiments showed a significantly higher relative expression of known corneal epithelial stem cell markers in the Sox9- expressing cells obtained by FACS sorting. We found that there was up regulation of ABCG2 (5 fold), p63 (18 fold), and Cdh2 (3.6 fold), in the sox9 expressing cells. In contrast, when we analyzed the corneal differentiation markers in these cells, we found down regulation of Krt12 (5 fold) and Ivl (2.5 fold).
Sox9 may be a novel marker of corneal epithelial stem cells given its localization to basal corneal epithelial layers an its co-expression with other putative stem cell markers. A possible role for Sox9 in mediating corneal epithelial stemness could have utility in the diagnosis and treatment of corneal limbal stem cell deficiency.
This PDF is available to Subscribers Only