Epithelial-mesenchymal transition and proliferation of retinal pigment epithelial cells initiated upon loss of cell-cell contact
| Autor: | Shigeo Tamiya, LanHsin Liu, Henry J. Kaplan |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Swine
Cellular differentiation Blotting Western Cell Communication Retinal Pigment Epithelium Cell morphology Phagocytosis medicine Cell Adhesion Animals Vimentin Epithelial–mesenchymal transition Cell adhesion Eye Proteins Fluorescent Antibody Technique Indirect Cells Cultured Cell Proliferation Retinal pigment epithelium Cadherin Chemistry Mesenchymal stem cell Cell Differentiation Epithelial Cells Cadherins Rod Cell Outer Segment Actins Cell biology medicine.anatomical_structure Microscopy Electron Scanning sense organs Sodium-Potassium-Exchanging ATPase Myofibroblast |
| Zdroj: | Investigative ophthalmologyvisual science. 51(5) |
| ISSN: | 1552-5783 |
| Popis: | Purpose Molecular mechanisms that initiate epithelial-mesenchymal transition (EMT) involved in ocular fibrotic complications remain elusive. Studies were conducted to examine the role of cell-cell contact in regulating EMT and proliferation of retinal pigment epithelial (RPE) cells. Methods Porcine RPE cells were isolated as sheets and cultured in vitro on lens capsules. Cell morphology was examined by microscopy. Western blot analysis and immunostaining were used to follow protein expression. Cell proliferation and RPE function were assessed by BrdU incorporation and phagocytosis assay, respectively. Results RPE cells in the center of each sheet maintained cell-cell contacts and retained a differentiated phenotype. Disruption of cadherin function in these cells resulted in the loss of cell-cell contact and the concomitant induction of mesenchymal marker protein expression and cell proliferation. RPE cells at the edge of the sheet migrated away from the sheet, underwent EMT, and initiated proliferation, which was accompanied by a switch in cadherin expression from P-cadherin to N-cadherin. Although TGF-beta is thought to be a classic inducer of EMT, it was unable to initiate EMT in RPE cells maintaining cell-cell contact. However, change to alpha-SMA-positive myofibroblasts was induced by TGF-beta in cells that had already undergone EMT. Conclusions EMT and the onset of proliferation in RPE cells is initiated by loss of cell-cell contact. TGF-beta cannot initiate EMT or the proliferation of RPE cells maintaining cell-cell contact but appears to play an important secondary role downstream of EMT in inducing transition to a myofibroblast phenotype-a phenotype linked to the development of fibrotic complications. |
| Databáze: | OpenAIRE |
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