Biochemistry/Molecular Biology - ARVO

ARVO 2013 Annual Meeting Abstracts by Scientific Section/Group - Biochemistry/Molecular BiologyCommercial Relationships: Payam Falatoonzadeh, None; GraceB. Woo, None; Nitin Udar, Illumina (E); Shari Atilano, None;Marilyn Chwa, None; Miceli V. Michael, None; S MichalJazwinski, None; Cristina M. Kenney, NoneSupport: Supported by Discovery Eye Foundation, GuentherFoundation, Beckman Macular Research Initiative, Polly andMichael Smith foundation, Max Factor Family Foundation, SkirballFoudnation, Lincy Foundation, Iris and B. Gerald Cantor Foundation,Unrestricted grant from Research to Prevent Blindness, grant fromNational Institute on Aging (AG006168)Program Number: 4999 Poster Board Number: A0128Presentation Time: 2:45 PM - 4:30 PMExpression of VEGF-C, VEGF-D and their Cognate Receptors inExperimental Choroidal Neovascularization and Clinical AMDKameran Lashkari 1 , Jie Ma 1 , Gianna Teague 1 , Jorge G. Arroyo 2 .1 Schepens Eye Research Institute/ Massachusetts Eye & Ear, HarvardMed School, Boston, MA; 2 Beth Israel Deaconess Medical Center,Harvard Med School, Boston, MA.Purpose: VEGF-C has been implicated in tumor-associated andcorneal angiogenesis through its effects on lymphangiogenesis andactivation of VEGFR3. However, recent evidence implicates VEGF-C and D in pathological angiogenesis in absence of lymphaticinvolvement, possibly through activation of VEGFR2. The goal ofthis study is to define the role of VEGF-C and its cognate receptors inretinal angiogenesis including neovascular AMD and relateddisorder.Methods: The levels of VEGF-C and D, and soluble VEGFreceptors, R1, R2 and R3 were measured in vitreous samples ofsubjects with various vitreoretinal conditions using combination ofLuminex and Elisa assays. The mouse model of laser-inducedchoroidal neovascularization (CNV) was used to detect theexpression of VEGF-C, D and receptors, R2 and R3 using imagingand immunohistochemistry. Expression of these factors was alsoexamined in donor eyes with various stages of AMD.Results: Both VEGF-C and D and soluble (s) R1, R2 and R3 weredetectable in the human vitreous. sR3 levels averaged 200 pg/ml incontrol subjects, and one log order higher than sR2 levels. Therespective concentrations of VEGF-C and D positively correlatedwith age and were affected by retinal diseases including AMD.VEGF-C and its cognate receptors were detected within cellularcomponents of laser-induced CNV membranes. A similar expressionpattern was seen in clinical specimens of AMD.Conclusions: Based on these examinations, VEGF-C, D andsVEGFRs are detectable in the human vitreous, positively associatedwith age, and affected by disease states such as AMD. VEGF-C andD were detected within experimental and clinical CNV membranes.VEGF-C and D may participate in pathological angiogenic processessuch as neovascular AMD in absence of any observedlymphangiogenesis.Commercial Relationships: Kameran Lashkari, CircadianTechnologies (F), Regeneron (R); Jie Ma, None; Gianna Teague,None; Jorge G. Arroyo, NoneSupport: Circadian TechnologiesProgram Number: 5000 Poster Board Number: A0129Presentation Time: 2:45 PM - 4:30 PMMitochondrial DNA Damage Increases with Age-related MacularDegeneration in the RPE but not Neural RetinaMARCIA R. TERLUK 1 , Lauren M. Soukup 2 , Sandra R. Montezuma 1 ,Deborah A. Ferrington 1 . 1 Ophthalmology and Visual Neurosciences,University of Minnesota, Minneapolis, MN; 2 Biology, University ofSt. Thomas, St. Paul, MN.Purpose: Reports of increased mitochondrial DNA (mtDNA)damage in the retinal pigment epithelium (RPE) from human donorswith age-related macular degeneration (AMD) provide compellingevidence supporting the hypothesis that mitochondrial dysfunctionplays a prominent role in AMD pathology (Karunadharma et al.,2010; Lin et al., 2011). However, it is still not clear whether thisdamage is limited to the RPE or if it also involves the neural retina.The purpose of this study was to determine if (1) mtDNA damageincreases in the neural retina with AMD, and (2) the extent ofmtDNA damage in the RPE correlates with the extent of damage inthe neural retina in individual donors.Methods: Human donor eyes were obtained from the MinnesotaLions Eye Bank, Minneapolis, MN. Genomic DNA was isolated froma 5 mm trephine punch of the macular region of the RPE and neuralretina from human donor eyes categorized into four progressivestages of AMD (MGS 1-4, Olsen and Feng, 2003). MitochondrialDNA damage was assessed in 32 donors (n=8/stage) using the longextension polymerase chain reaction. In this assay, decreasedamplification reflects increased DNA damage. The amplified productwas quantified using Pico Green fluorescent dye. Statistical analysisincluded one way ANOVA and Tukey’s post-hoc tests to determine ifthere was a significant increase in mtDNA damage with AMDprogression. Pearson Product-Moment Correlation analysis wasperformed comparing the extent of damage in the RPE and retina foreach donor to determine if there was an association between damagein these two ocular regions.Results: There was no significant change in mtDNA damage in themacula of the neural retina when comparing age-matched controlsand donors with AMD (p=0.29). Furthermore, comparison of mtDNAdamage in the RPE and retina from individual donors showed nocorrelation (Pearson’s r=0.03; p>0.10) between the extent of mtDNAdamage in these two macular tissues.Conclusions: Collectively our data indicates that mtDNA damagethat increases with AMD is limited to the RPE and not the retina.These results suggest that targeting treatments that protect themitochondria in the RPE may be the most efficacious therapeuticstrategy for AMD.Commercial Relationships: MARCIA R. TERLUK, None;Lauren M. Soukup, None; Sandra R. Montezuma, None; DeborahA. Ferrington, NoneSupport: Unrestricted grant to the Department of OVNS fromResearch to Prevent Blindness; Beckman Initiative for MacularResearch, Minnesota Lions Club.Program Number: 5001 Poster Board Number: A0130Presentation Time: 2:45 PM - 4:30 PMOxidative Stress-Induced Necrosis in RPE CellsJakub Hanus 1 , William C. Anderson 1 , Peng Jin 3 , Qinghua Liu 4 ,Shusheng Wang 1, 2 . 1 Cell and Molecular Biology, Tulane University,New Orleans, LA; 2 Ophthalmology, Tulane University, New Orleans,LA; 3 Human Genetics, Emory University, Atlanta, GA;4 Biochemistry, University of Texas Southwestern Medical Center,Dallas, TX.Purpose: Atrophy of retinal pigment epithelial (RPE) cells andphotoreceptors in the macula is characteristic of geographic atrophy(GA), an advanced state of dry age-related macular degeneration(AMD). RPE cells are subjected to chronic oxidative stress.Currently, the mechanism of oxidative stress-induced RPE cell deathis controversial, with most pointing to a dominant role for apoptosis.However, apoptosis does not induce inflammatory response, which isnot consistent with chronic inflammation observed in dry AMD. Weset out to clarify the mechanism of oxidative stress-induced RPE celldeath using cultured RPE cells. We test the hypothesis that necrosis is©2013, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permissionto reproduce any abstract, contact the ARVO Office at arvo@arvo.org.