The Effect of Hydrogen Peroxide on Sarco/Endoplasmic and Plasma Membrane Calcium ATPase Gene Expression in Cultured Human Lens Epithelial Cells
M.J Marian1, P Mukhopadhyay2, D Borchman*, 3, D Tang3, C.A Paterson3
Identifiers and Pagination:Year: 2008
First Page: 123
Last Page: 129
Publisher Id: TOOPHTJ-2-123
Article History:Received Date: 25/4/2008
Revision Received Date: 9/6/2008
Acceptance Date: 17/6/2008
Electronic publication date: 7/7/2008
Collection year: 2008
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.5/), which permits unrestrictive use, distribution, and reproduction in any medium, provided the original work is properly cited.
The loss of calcium homeostasis in the lens of the eye appears to be a factor contributing to lens opacity. In the human lens, calcium homeostasis depends on the Ca2+-ATPase pumps found only in the epithelium. A plasma membrane calcium pump, PMCA2 is upregulated in human cataractous lenses. To determine if oxidation caused the plasma membrane Ca2+-ATPases (PMCA) or sarcoplasmic/endoplasmic Ca2+-ATPases (SERCA) to become upregulated, we cultured a human lens epithelial cell line, in the presence of hydrogen peroxide. We observed an increase in PMCA1, PMCA2 SERCA2b and SERCA3 mRNA levels and protein expression with increasing hydrogen peroxide concentrations and treatment times. Hydrogen peroxide caused a rise in the intracellular calcium which could be an initiating factor in the concerted upregulation of PMCA1 and SERCA3. Our data support the idea that oxidative stress could contribute to a selective rise in PMCA/SERCA expression in human cataractous lenses.