Retinal Degenerative Diseases pp 757-763 | Cite as
RPE Cell and Sheet Properties in Normal and Diseased Eyes
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Abstract
Previous studies of human retinal pigment epithelium (RPE) morphology found spatial differences in density: a high density of cells in the macula, decreasing peripherally. Because the RPE sheet is not perfectly regular, we anticipate that there will be differences between conditions and when and where damage is most likely to begin. The purpose of this study is to establish relationships among RPE morphometrics in age, cell location, and disease of normal human and AMD eyes that highlight irregularities reflecting damage. Cadaveric eyes from 11 normal and 3 age-related macular degeneration (AMD) human donors ranging from 29 to 82 years of age were used. Borders of RPE cells were identified with phalloidin. RPE segmentation and analysis were conducted with CellProfiler. Exploration of spatial point patterns was conducted using the “spatstat” package of R. In the normal human eye, with increasing age, cell size increased, and cells lost their regular hexagonal shape. Cell density was higher in the macula versus periphery. AMD resulted in greater variability in size and shape of the RPE cell. Spatial point analysis revealed an ordered distribution of cells in normal and high spatial disorder in AMD eyes. Morphometrics of the RPE cell readily discriminate among young vs. old and normal vs. diseased in the human eye. The normal RPE sheet is organized in a regular array of cells, but AMD exhibited strong spatial irregularity. These findings reflect on the robust recovery of the RPE sheet after wounding and the circumstances under which it cannot recover.
Keywords
Retinal pigmented epithelium (RPE) Flatmount En face Spatial point patterns Age related macular degeneration (AMD) Cadaveric eyes Spatstat CellProfiler Macula Periphery Nearest neighbor distanceNotes
Acknowledgments
Support provided by Research to Prevent Blindness; NIH R01EY021592, P30EY06360, R01EY016470, R01EY014026, UL1TR000454, and TL1TR000456; Abraham J. and Phyllis Katz Foundation; USAMRAA DOD W81XWH-12-1-0436; The Emory Neurosciences Initiative.
References
- Ambati J, Fowler BJ (2012) Mechanisms of age-related macular degeneration. Neuron 75:26–39CrossRefPubMedPubMedCentralGoogle Scholar
- Baddeley A, Turner R (2005) Spatstat: an R package for analyzing spatial point patterns. J Statistic Soft 12:1–42Google Scholar
- Bhutto I, Lutty G (2012) Understanding age-related macular degeneration (AMD): relationships between the photoreceptor/retinal pigment epithelium/Bruch’s membrane/choriocapillaris complex. Mol Aspect Med 33:295–317CrossRefGoogle Scholar
- Burke JM, Hjelmeland LM (2005) Mosaicism of the retinal pigment epithelium: seeing the small picture. Mol Intervent 5:241–249CrossRefGoogle Scholar
- Chrenek MA, Dalal N, Gardner C et al (2012) Analysis of the RPE sheet in the rd10 retinal degeneration model. Adv Exp Med Biol 723:641–647CrossRefPubMedPubMedCentralGoogle Scholar
- Gao H, Hollyfield JG (1992) Aging of the human retina. Differential loss of neurons and retinal pigment epithelial cells. Investig Ophthalmol Vis Sci 33:1–17Google Scholar
- Jiang Y, Qi X, Chrenek MA et al (2013) Functional principal component analysis reveals discriminating categories of retinal pigment epithelial morphology in mice. Investig Ophthalmol Vis Sci 54:7274–7283CrossRefGoogle Scholar
- Jiang Y, Qi X, Chrenek MA et al (2014) Analysis of mouse RPE sheet morphology gives discriminatory categories. Adv Exp Med Biol 801:601–607CrossRefPubMedPubMedCentralGoogle Scholar
- Kalnins VI, Sandig M, Hergott GJ et al (1995) Microfilament organization and wound repair in retinal pigment epithelium. Biochem Cell Biol 73:709–722CrossRefPubMedGoogle Scholar
- Lamprecht MR, Sabatini DM, Carpenter AE (2007) CellProfiler: free, versatile software for automated biological image analysis. Biotechniques 42:71–75CrossRefPubMedGoogle Scholar
- Liang F-Q, Godley BF (2003) Oxidative stress-induced mitochondrial DNA damage in human retinal pigment epithelial cells: a possible mechanism for RPE aging and age-related macular degeneration. Exp Eye Res 76:397–403CrossRefPubMedGoogle Scholar
- Nagai H, Kalnins VI (1996) Normally occurring loss of single cells and repair of resulting defects in retinal pigment epithelium in situ. Exp Eye Res 62:55–61CrossRefPubMedGoogle Scholar
- Negi A, Marmor MF (1984) Healing of photocoagulation lesions affects the rate of subretinal fluid resorption. Ophthalmol 91:1678–1683CrossRefGoogle Scholar
- Rizzolo LJ (2014) Barrier properties of cultured retinal pigment epithelium. Exp Eye Res 126:16–26CrossRefPubMedGoogle Scholar
- Roider J, Michaud NA, Flotte TJ et al (1992) Response of the retinal pigment epithelium to selective photocoagulation. Arch Ophthalmol 110:1786–1792CrossRefPubMedGoogle Scholar
- Shirinifard A, Glazier JA, Swat M et al (2012) Adhesion failures determine the pattern of choroidal neovascularization in the eye: a computer simulation study. PLoS Comp Biol 8:e1002440CrossRefGoogle Scholar
- Thompson DW (1942). On Growth and From. A new edition. Cambridge at the University Press. Cambridge, England, UK.Google Scholar
- van Lookeren CM, LeCouter J, Yaspan BL et al (2014) Mechanisms of age-related macular degeneration and therapeutic opportunities. J Pathol 232:151–164CrossRefGoogle Scholar
- Watzke RC, Soldevilla JD, Trune DR (1993) Morphometric analysis of human retinal pigment epithelium: correlation with age and location. Curr Eye Res 12:133–142CrossRefPubMedGoogle Scholar