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Effects of Sp1 overexpression on cultured human corneal stromal cells
Author(s) -
Shen Xiang,
Park JeongSeok,
Qiu Ye,
Sugar Joel,
Yue Beatrice Y J T
Publication year - 2009
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/j.1365-2443.2009.01340.x
Subject(s) - stromal cell , biology , cathepsin b , transfection , downregulation and upregulation , cathepsin , cathepsin d , keratoconus , microbiology and biotechnology , cathepsin l , cornea , blot , cell culture , cancer research , enzyme , biochemistry , genetics , neuroscience , gene
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 α1‐proteinase inhibitor (α1‐PI). We transfected cultured human corneal stromal cells to overexpress Sp1. The resulting effects on cathepsin B and α1‐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 α1‐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.