| Title | Effects of Sp1 overexpression on cultured human corneal stromal cells. | | Author(s) | Shen X, Park JS, Qiu Y, Sugar J, Yue BY | | Institution | Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago College of Medicine, Chicago, IL, USA. | | Source | Genes Cells 2009 Sep 16. | | Abstract | Sp1, a transcription factor, is upregulated in keratoconus, a cornea-thinning disease. Keratoconus corneas have also been shown to contain increased levels of degradative enzymes such as cathepsin B and decreased proteinase inhibitors such as alpha1-proteinase inhibitor (alpha1-PI). We transfected cultured human corneal stromal cells to overexpress Sp1. The resulting effects on cathepsin B and alpha1-PI levels as well as the cellular proliferative and apoptotic activities were examined by Western blotting and cytochemical staining. It was found that the Sp1 transfected cells contained a greater amount of cathepsin B than did mock transfected controls. The activity of cathepsin B was also increased. By contrast, the protein level of alpha1-PI was lowered in corneal stromal cells upon Sp1 overexpression. The Sp1-induced alterations thus mimicked closely those observed in keratoconus, supporting the notion that Sp1 upregulation may be a key factor contributing directly to the disease development. Furthermore, the apoptotic activity was unaffected in Sp1 transfectants but the proliferation was inhibited, consistent with the idea that Sp1 may play a role in differentiation of corneal cells. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 19758310 |
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