HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (13) Citing Articles via Google Scholar Google Scholar Articles by Wang, X. Articles by Beebe, D. C. Search for Related Content PubMed PubMed Citation Articles by Wang, X. Articles by Beebe, D. C.

Expression and Regulation of -, ß-, and -Crystallins in Mammalian Lens Epithelial Cells

¹From the Departments of Ophthalmology and Visual Sciences and ²Cell Biology and Physiology, Washington University, St. Louis, Missouri.

PURPOSE. In the mammalian lens, the expression of the ß- and -crystallin families is thought to be limited to fiber cells. However, several studies detected these proteins or their mRNAs in human lens epithelial cells. To resolve this apparent discrepancy, 14 crystallin mRNAs were examined and the expression and subcellular distribution of selected crystallin proteins in lens epithelial cells determined.

METHODS. Transcript levels were analyzed by quantitative real-time PCR using mRNA from P3 rat lens epithelia cultured for 0 or 20 hours or 4 or 7 days in basal medium or with added FGF2. Antibodies to ßB1-, S-, A-, and B-crystallins were used for Western blot analysis of proteins extracted from adult mouse, human, bovine, rabbit, and rat lens epithelial and fiber cells. Rat lenses or lens epithelia were rapidly fixed in situ, 30 minutes after death, or after dissection from the lens, and the intracellular distributions of crystallins were examined by immunostaining and confocal microscopy.

RESULTS. Four patterns of crystallin gene expression were detected in cultured lens epithelia. Transcripts encoding most ß- and -crystallins were detectable and, in some cases, abundant at the time of explantation. Changes in crystallin protein levels in P3 epithelia cultured in basal or FGF-supplemented medium generally reflected the changes in their mRNAs. ßB1- and S-crystallins were abundant in adult human, mouse, rat, rabbit, and bovine lens epithelial cells. The -, ß- and -crystallins were found in distinct subcellular locations in adult lens epithelial cells. These proteins dramatically relocalized during fiber cell differentiation and after death and/or dissection of the lens epithelium.

CONCLUSIONS. ßB1- and S-crystallins are normally abundant in adult mammalian lens epithelial cells. Complex programs of transcription and degradation regulate the accumulation of crystallin mRNAs in lens epithelial cells after stress, at different ages, and during cell differentiation. Because crystallins selectively localize in distinct subcellular compartments during differentiation or stress, they may function to protect lens cells from injury. After stress, most A- and B-crystallin subunits are not in the same macromolecular complexes.

This article has been cited by other articles:

				M. A. Cooper, A. I. Son, D. Komlos, Y. Sun, N. J. Kleiman, and R. Zhou Loss of ephrin-A5 function disrupts lens fiber cell packing and leads to cataract PNAS, October 28, 2008; 105(43): 16620 - 16625. [Abstract] [Full Text] [PDF]

				S. Lofgren, M. R. Fernando, K.-Y. Xing, Y. Wang, C. A. Kuszynski, Y.-S. Ho, and M. F. Lou Effect of Thioltransferase (Glutaredoxin) Deletion on Cellular Sensitivity to Oxidative Stress and Cell Proliferation in Lens Epithelial Cells of Thioltransferase Knockout Mouse Invest. Ophthalmol. Vis. Sci., October 1, 2008; 49(10): 4497 - 4505. [Abstract] [Full Text] [PDF]

				J.-h. Xi, F. Bai, J. Gross, R. R. Townsend, A. S. Menko, and U. P. Andley Mechanism of Small Heat Shock Protein Function in Vivo: A KNOCK-IN MOUSE MODEL DEMONSTRATES THAT THE R49C MUTATION IN {alpha}A-CRYSTALLIN ENHANCES PROTEIN INSOLUBILITY AND CELL DEATH J. Biol. Chem., February 29, 2008; 283(9): 5801 - 5814. [Abstract] [Full Text] [PDF]

				L. M. Hodgkinson, G. Duncan, L. Wang, C. J. Pennington, D. R. Edwards, and I. M. Wormstone MMP and TIMP Expression in Quiescent, Dividing, and Differentiating Human Lens Cells Invest. Ophthalmol. Vis. Sci., September 1, 2007; 48(9): 4192 - 4199. [Abstract] [Full Text] [PDF]

				T. Blankenship, L. Bradshaw, B. Shibata, and P. FitzGerald Structural Specializations Emerging Late in Mouse Lens Fiber Cell Differentiation Invest. Ophthalmol. Vis. Sci., July 1, 2007; 48(7): 3269 - 3276. [Abstract] [Full Text] [PDF]

				W. Guo, F. Shang, Q. Liu, L. Urim, M. Zhang, and A. Taylor Ubiquitin-proteasome pathway function is required for lens cell proliferation and differentiation. Invest. Ophthalmol. Vis. Sci., June 1, 2006; 47(6): 2569 - 2575. [Abstract] [Full Text] [PDF]

				S. A. Riazuddin, A. Yasmeen, W. Yao, Y. V. Sergeev, Q. Zhang, F. Zulfiqar, A. Riaz, S. Riazuddin, and J. F. Hejtmancik Mutations in {beta}B3-Crystallin Associated with Autosomal Recessive Cataract in Two Pakistani Families Invest. Ophthalmol. Vis. Sci., June 1, 2005; 46(6): 2100 - 2106. [Abstract] [Full Text] [PDF]