Biochemistry/Molecular Biology - ARVO

ARVO 2013 Annual Meeting Abstracts by Scientific Section/Group - Biochemistry/Molecular Biology(rods) and synuclein gamma (ganglion cells) were reduced. We thentested some candidate genes implicated in biochemical pathwaystaking place in the retina such as visual cycle and retinoic acidmetabolism. ALDH1A1, ALDH1A3, RDH5 and RDH10 were foundto be reduced within the MacTel area while PPARG was increased.From differential display, after testing ‘’macula’’ compared to‘’temporal to macula’’ areas, ADARB1 was found to be reduced inthe macula.Conclusions: Human retina up to 7 hours post mortem can be usedfor gene expression analysis experiments. Using qPCR anddifferential display techniques, genes differentially expressedbetween the macula and the peripheral retina were found.Confirmation of the differentially expressed genes needs to be doneby immunohistochemistry.Figure 1: Schematic representation of the location of the fivedifferent dissected retinal regions.Commercial Relationships: Kristis Vevis, None; Michael B.Powner, Novartis (R); Jenny Mckenzie, None; Meidong Zhu,None; Mark C. Gillies, Novartis (R), Pfizer (R), Allergan (F), Bayer(F); Marcus Fruttiger, AstraZeneca (F), Novartis (F), Novartis (C),Amakem (F)Support: Lowy Medical Research Institute LTDProgram Number: 1592 Poster Board Number: D0019Presentation Time: 8:30 AM - 10:15 AMIdentification of piRNAs in the RetinaYingfeng Zheng 1, 2 , Qilin Wang 1 , Xinyang Lin 1 , Mingguang He 1 .1 Zhongshan Ophthalmic Center, Guangzhou, China; 2 Singapore EyeResearch Institute, Singapore, Singapore.Purpose: Piwi-interacting RNAs (piRNAs), a class of small noncodingRNAs associated with Piwi, maintain genomic integrity bytransposon silencing. Outside of the germline, the roles of piRNAs insomatic tissues are not fully understood. We examine if piRNAs andPiwi-like molecules are expressed in retina.Methods: Mice aged 8 weeks were sacrificed and the retina, liver,and testis tissues were obtained. piRNA level was assessed byquantitative reverse transcription PCR (qPCR) in mouse retina.Mouse liver and testis served as controls. In another experiment, weassessed the expression of Piwi-like genes (Piwi-like-1 to -4) inhuman retinal pigment epithelial (RPE) cells in vitro using qPCR.Results: Expression of several piRNAs was observed in mouse retinatissue. These included DQ541777, DQ555094, DQ689086,DQ705026, and DQ719597 that have previously been reported toexpress in somatic tissues such as liver, heart and brain. We alsodemonstrated mRNA expression of Piwi-like genes, particularlyPiwi-like-2 and -4 genes, in cultured RPE cells.Conclusions: These findings indicate that piRNAs and Piwi-familyproteins exist in retina. They might play important roles in the properfunction of the eye.Commercial Relationships: Yingfeng Zheng, None; Qilin Wang,None; Xinyang Lin, None; Mingguang He, NoneSupport: This work is supported by National Natural ScienceFoundation of China 81100686Program Number: 1593 Poster Board Number: D0020Presentation Time: 8:30 AM - 10:15 AMUnpredictable Consequences of Systemic Valproic AcidTreatment on the Rate of Photoreceptor Loss in Different Pde6bRd-mutationsKenneth P. Mitton 1, 2 , David W. Byrd 1 , Eduardo Guzman 1, 2 , AdrianneWallace 1, 2 , Trung Tran 1 , Jason Sotzen 1 . 1 Control of Gene ExpressionLab, Eye Research Institute of Oakland University, Rochester, MI;2 Pediatric Retinal Research Laboratory, Eye Research Institute ofOakland University, Rochester, MI.Purpose: VPA is an FDA approved anticonvulsant whose activity asa histone deacetylase inhibitor was discovered only recently,generating intense interest for its potential use in epigenetic therapy.Clinical trials are recruiting patients to evaluate VPA’s therapeuticpotential for AD-RP. Given that VPA’s effects on gene expressionare non-specific, could VPA reduce or accelerate photoreceptor lossin RP-patients harboring different mutations? We compared systemicVPA treatment on retinal neurotrophic gene expression andphotoreceptor loss in rd-mice with different mutations of Pde6b.Methods: Expression of Bdnf, Gdnf, Cntf, and Fgf2 were measuredby real-time PCR after single and multiple VPA doses in wild-typeand Pde6b rd1/rd1 mice. Pde6b rd10/rd10 mice were also treated toevaluate a partial loss-of-function model. Retinal morphology wasassessed with virtual microscopy.Results: In post-natal mice, a single systemic dose of VPA causedsubstantial increases in the expression of Bdnf (3x) and Gdnf (10x) inthe neural retina within 18 hours. Cntf and Fgf2 expression decreased70%. These large gene expression changes did not persist aftermultiple days of dosing. Daily injections with VPA (P9-P19) reducedphotoreceptor loss in Pde6b rd1/rd1 mice. By P20, VPA treated micehad several rows of rod nuclei, compared to a single row remainingin PBS injected littermates. Starting treatment later, or dosing everysecond day, also rescued photoreceptors. VPA treatment did notreduce rod loss in Pde6b rd10/rd10 mice. Some PBS-treatedPde6b rd10/rd10 littermates may have had slightly more rod-nuclei thantheir VPA treated counterparts, although this difference was notstatistically significant with the numbers tested. VPA disrupted thelens bow region morphology in some mice.Conclusions: A single systemic dose of VPA caused increases anddecreases the retinal expression of different neurotrophic factorgenes. While systemic VPA treatment slowed the rate ofphotoreceptor loss in Pde6b rd1/rd1 mice, it did not benefit degeneratingphotoreceptors in Pde6b rd10/rd10 mice. We conclude that systemicVPA was not universally beneficial for degenerations involvingdifferent functional mutations of the same gene. These results suggestthat human clinical trials with VPA should best be limited to AD-RPpatients with identified molecular mutations.Commercial Relationships: Kenneth P. Mitton, None; David W.Byrd, None; Eduardo Guzman, None; Adrianne Wallace, None;Trung Tran, None; Jason Sotzen, NoneSupport: 1. ROPARD 2. OU Center for Biomedical Research 3.NIH/NEIProgram Number: 1594 Poster Board Number: D0021Presentation Time: 8:30 AM - 10:15 AMMicroRNA-21 (miR-21) Induces Down-regulation Of PEDF InRetinal Pigmented Epithelial Cells By Suppression Of PPARAlphaManuela Bartoli 1 , Chaunte E. Stampley 2 , Sean Shaw 1 , Pamela M.Martin 3 , Folami Lamoke 1 . 1 Ophthalmology, Georgia Health Sciences©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.