Purchase this article with an account.
Yasuhiko Tanaka, Jun Utsumi, Mizuo Matsui, Tetsuo Sudo, Noriko Nakamura, Masato Mutoh, Akemi Kajita, Saburo Sone, Kazuteru Kigasawa, Masahiko Shibuya, Venkat N. Reddy, Qiang Zhang, Takeshi Iwata; Purification, Molecular Cloning, and Expression of a Novel Growth-Promoting Factor for Retinal Pigment Epithelial Cells, REF-1/TFPI-2. Invest. Ophthalmol. Vis. Sci. 2004;45(1):245-252. doi: https://doi.org/10.1167/iovs.03-0230.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
purpose. Retinal pigment epithelial (RPE) cells are known to play important roles in maintaining the homeostasis of the retina and in controlling choroidal neovascularization. The purpose of this study was to identify a factor or factors that would stimulate RPE cells to proliferate.
methods. To isolate such a factor, 100 L of human-fibroblast–conditioned medium underwent ion-exchange, hydrophobic, and reverse-phase chromatographies followed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis. The growth-promoting activity of the factor was examined in a human K-1034 RPE cell line and human primary RPE cells.
results. The different chromatographic processes isolated a 31-kDa factor that had RPE cell growth–promoting properties. This factor, which we have named RPE cell factor (REF)-1, promotes growth of RPE cells but not of human umbilical vein endothelial cells (HUVECs). The amino-terminal sequence and molecular cloned cDNA of REF-1 were identical with those of tissue-factor pathway inhibitor (TFPI)-2, a family of TFPIs, and placental protein (PP)-5, a serine protease inhibitor. The cDNA expression of REF-1/TFPI-2 with pcDL-pSRα vector in Chinese hamster ovary (CHO) cells confirmed the growth-promoting activity for RPE cells. The major component of the recombinant REF-1/TFPI-2 expressed in CHO cells had a molecular mass of 31 kDa and exerted growth-promoting activity in RPE cells but not in human endothelial cells and fibroblasts in vitro. REF-1/TFPI-2 also had protease inhibitory activity. The other family factor, TFPI-1, did not promote RPE cell growth.
conclusions. REF-1/TFPI-2 is a novel growth-promoting factor for RPE cells but not for endothelial cells and fibroblasts. Its properties make it potentially beneficial for intraocular therapy for the repair and maintenance of RPE cells.
This PDF is available to Subscribers Only