Anand Swaroop

National Institutes of Health, 베서스다, Maryland, United States

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Publications (287)1824.45 Total impact

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    ABSTRACT: Retinal neurodegenerative diseases are especially attractive targets for gene replacement therapy, which appears to be clinically effective for several monogenic diseases. X-linked forms of retinitis pigmentosa (XLRP) are relatively severe blinding disorders, resulting from progressive photoreceptor dysfunction primarily caused by mutations in RPGR or RP2 gene. With a goal to develop gene therapy for the XLRP-RP2 disease, we first performed detailed characterization of the Rp2-knockout (Rp2-KO) mice and observed early onset cone dysfunction, which was followed by progressive cone degeneration, mimicking cone vision impairment in XLRP patients. The mice also exhibited distinct and significantly delayed falling phase of photopic b-wave of electroretinogram (ERG). Concurrently, we generated a self-complementary adeno-associated viral (AAV) vector carrying human RP2 coding sequence and demonstrated its ability to mediate stable RP2 protein expression in mouse photoreceptors. A long-term efficacy study was then conducted in Rp2-KO mice following AAV-RP2 vector administration. Preservation of cone function was achieved with wide dose range over 18-month duration, as evidenced by photopic ERG and optomotor tests. The slower b-wave kinetics was also completely restored. Morphologically, the treatment preserved cone viability, corrected mis-trafficking of M-cone opsin and restored cone PDE6 expression. The therapeutic effect was achieved even in mice that received treatment at an advanced disease stage. The highest AAV-RP2 dose group demonstrated retinal toxicity, highlighting the importance of careful vector dosing in designing future human trials. The wide range of effective dose, a broad treatment window and long-lasting therapeutic effects should make the RP2 gene therapy attractive for clinical development.
    Human Molecular Genetics 09/2015; DOI:10.1093/hmg/ddv354 · 6.39 Impact Factor
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    ABSTRACT: Whole exome sequencing (WES) is a powerful technique for identifying sequence changes in the human genome. The goal of this study was to delineate the genetic defects in patients with inherited retinal diseases (IRDs) using WES. WES was performed on 90 patient DNA samples from 68 families and 226 known genes for IRDs were analyzed. Sanger sequencing was used to validate potential pathogenic variants that were also subjected to segregation analysis in families. Thirty-three causative mutations (19 novel and 14 known) in 25 genes were identified in 33 of the 68 families. The vast majority of mutations (30 out of 33) have not been reported in the Israeli and the Palestinian populations. Nine out of the 33 mutations were detected in additional families from the same ethnic population, suggesting a founder effect. In two families, identified phenotypes were different from the previously reported clinical findings associated with the causative gene. This is the largest genetic analysis of IRDs in the Israeli and Palestinian populations to date. We also demonstrate that WES is a powerful tool for rapid analysis of known disease genes in large patient cohorts.
    Scientific Reports 08/2015; 5:13187. DOI:10.1038/srep13187 · 5.58 Impact Factor
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    ABSTRACT: The derivation of three-dimensional (3-D) stratified neural retina from pluripotent stem cells has permitted investigations of human photoreceptors. We have generated a H9 human embryonic stem cell subclone that carries a GFP reporter under the control of the promoter of cone-rod homeobox (CRX), an established marker of post-mitotic photoreceptor precursors. The CRXp-GFP reporter replicates endogenous CRX expression in vitro when the H9 subclone is induced to form self-organizing 3-D retina-like tissue. At day 37, CRX+ photoreceptors appear in the basal or middle part of neural retina and migrate to apical side by day 67. Temporal and spatial patterns of retinal cell type markers recapitulate the predicted sequence of development. Cone gene expression is concomitant with CRX, whereas rod differentiation factor NRL is first observed at day 67. At day 90, robust expression of NRL and its target nuclear receptor NR2E3 is evident in many CRX+ cells, while minimal S-opsin and no rhodopsin or L/M-opsin is present. The transcriptome profile, by RNA-seq, of developing human photoreceptors is remarkably concordant with mRNA and immunohistochemistry data available for human fetal retina although many targets of CRX, including phototransduction genes, exhibit a significant delay in expression. We report on temporal changes in gene signatures, including expression of cell surface markers and transcription factors; these expression changes should assist in isolation of photoreceptors at distinct stages of differentiation and in delineating co-expression networks. Our studies establish the first global expression database of developing human photoreceptors, providing a reference map for functional studies in retinal cultures. This article is protected by copyright. All rights reserved. © 2015 AlphaMed Press.
    Stem Cells 07/2015; DOI:10.1002/stem.2122 · 6.52 Impact Factor
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    ABSTRACT: Mutations in the Retinitis Pigmentosa GTPase Regulator (RPGR) gene account for over 70% of X-linked retinitis pigmentosa (XLRP) and 15-20% of all inherited retinal degeneration. Gene replacement therapy for RPGR-XLRP was hampered by the relatively slow disease progression in mouse models and by difficulties in cloning the full-length RPGR-ORF15 cDNA that includes a purine-rich 3'-coding region; however, its effectiveness has recently been demonstrated in four dogs with RPGR mutations. To advance the therapy to clinical stage, we generated new stable vectors in AAV8 or AAV9 carrying mouse and human full-length RPGR-ORF15 coding sequence and conducted a comprehensive long-term dose-efficacy study in Rpgr-knockout mice. After validating their ability to produce full-length proteins that localize to photoreceptor connecting cilia, we evaluated various vector doses in mice during a two-year study. We demonstrate that eyes treated with a single injection of mouse or human RPGR-ORF15 vector at an optimal dose maintained the expression of RPGR-ORF15 throughout the study duration and exhibited higher ERG amplitude, thicker photoreceptor layer, and better targeting of opsins to outer segments compared to sham-treated eyes. Furthermore, mice that received treatment at an advanced age also showed remarkable preservation of retinal structure and function. Retinal toxicity was observed at high vector doses, highlighting the importance of careful dose optimization in future clinical experiments. Our long-term dose-efficacy study should facilitate the design of human trials with human RPGR-ORF15 vector as a clinical candidate.
    Human Molecular Genetics 07/2015; 24(14). DOI:10.1093/hmg/ddv134 · 6.39 Impact Factor
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    ABSTRACT: Age-related macular degeneration (AMD) is a major cause of blindness in the western world. While genetic studies have linked both common and rare variants in genes involved in regulation of the complement system to increased risk of development of AMD, environmental factors, such as smoking and nutrition, can also significantly affect the risk of developing the disease and the rate of disease progression. Since epigenetics has been implicated in mediating, in part, the disease risk associated with some environmental factors, we investigated a possible epigenetic contribution to AMD. We performed genome-wide DNA methylation profiling of blood from AMD patients and controls. No differential methylation site reached genome-wide significance; however, when epigenetic changes in and around known GWAS-defined AMD risk loci were explored, we found small but significant DNA methylation differences in the blood of neovascular AMD patients near age-related maculopathy susceptibility 2 (ARMS2), a top-ranked GWAS locus preferentially associated with neovascular AMD. The methylation level of one of the CpG sites significantly correlated with the genotype of the risk SNP rs10490924, suggesting a possible epigenetic mechanism of risk. Integrating genome-wide DNA methylation analysis of retina samples with and without AMD together with blood samples, we further identified a consistent, replicable change in DNA methylation in the promoter region of protease serine 50 (PRSS50). These methylation changes may identify sites in novel genes that are susceptible to non-genetic factors known to contribute to AMD development and progression.
    Epigenetics: official journal of the DNA Methylation Society 06/2015; 10(8). DOI:10.1080/15592294.2015.1060388 · 4.78 Impact Factor
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    ABSTRACT: Genetic analysis of clinical phenotypes in consanguineous families is complicated by co-inheritance of large DNA regions carrying independent variants. Here we characterized a family with early onset cone-rod dystrophy (CRD) and muscular dystrophy. Homozygosity mapping followed by whole exome sequencing revealed a nonsense mutation, p.R270*, in ALMS1 and two novel potentially disease-causing missense variants, p.R1581C and p.Y2070C, in DYSF. ALMS1 and DYSF are genetically and physically linked on chromosome 2 in a genomic region suggested by homozygosity mapping and associated with Alström syndrome, which includes CRD, and with limb girdle muscular dystrophy, respectively. Affected family members lack additional systemic manifestations of Alström syndrome but exhibit mild muscular dystrophy. RNA-seq data did not reveal any significant variations in ALMS1 transcripts in the human retina. Our study thus implicates ALMS1 as a non-syndromic retinal disease gene and suggests a potential role of variants in interacting cilia genes in modifying clinical phenotypes. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Human Mutation 06/2015; 36(9):n/a-n/a. DOI:10.1002/humu.22822 · 5.14 Impact Factor
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    ABSTRACT: Worldwide, age-related macular degeneration (AMD) is a serious threat to vision loss in individuals over 50 years of age with a pooled prevalence of approximately 9%. For 2020, the number of people afflicted with this condition is estimated to reach 200 million. While AMD lesions presenting as geographic atrophy (GA) show high inter-individual variability, only little is known about prognostic factors. Here, we aimed to elucidate the contribution of clinical, demographic and genetic factors on GA progression. Analyzing the currently largest dataset on GA lesion growth (N = 388), our findings suggest a significant and independent contribution of three factors on GA lesion growth including at least two genetic factors (ARMS2-rs10490924 [P < 0.00088] and C3-rs2230199 [P < 0.00015]) as well as one clinical component (presence of GA in the fellow eye [P < 0.00023]). These correlations jointly explain up to 7.2% of the observed inter-individual variance in GA lesion progression and should be considered in strategy planning of interventional clinical trials aimed at evaluating novel treatment options in advanced GA due to AMD.Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
    PLoS ONE 05/2015; 10(5):e0126636. DOI:10.1371/journal.pone.0126636 · 3.23 Impact Factor
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    ABSTRACT: Distinct mutations in the centrosomal-cilia protein CEP290 lead to diverse clinical findings in syndromic ciliopathies. We show that CEP290 localizes to the transition zone in ciliated cells, precisely to the region of Y-linkers between central microtubules and plasma membrane. To create models of CEP290-associated ciliopathy syndromes, we generated Cep290(ko/ko) and Cep290(gt/gt) mice that produce no or a truncated CEP290 protein, respectively. Cep290(ko/ko) mice exhibit early vision loss and die from hydrocephalus. Retinal photoreceptors in Cep290(ko/ko) mice lack connecting cilia, and ciliated ventricular ependyma fails to mature. The minority of Cep290(ko/ko) mice that escape hydrocephalus demonstrate progressive kidney pathology. Cep290(gt/gt) mice die at mid-gestation, and the occasional Cep290(gt/gt) mouse that survives shows hydrocephalus and severely cystic kidneys. Partial loss of CEP290-interacting ciliopathy protein MKKS mitigates lethality and renal pathology in Cep290(gt/gt) mice. Our studies demonstrate domain-specific functions of CEP290 and provide novel therapeutic paradigms for ciliopathies. Published by Oxford University Press 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.
    Human Molecular Genetics 04/2015; 24(13). DOI:10.1093/hmg/ddv123 · 6.39 Impact Factor
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    ABSTRACT: Genomics and genetics have invaded all aspects of biology and medicine, opening uncharted territory for scientific exploration. The definition of "gene" itself has become ambiguous, and the central dogma is continuously being revised and expanded. Computational biology and computational medicine are no longer intellectual domains of the chosen few. Next generation sequencing (NGS) technology, together with novel methods of pattern recognition and network analyses, has revolutionized the way we think about fundamental biological mechanisms and cellular pathways. In this review, we discuss NGS-based genome-wide approaches that can provide deeper insights into retinal development, aging and disease pathogenesis. We first focus on gene regulatory networks (GRNs) that govern the differentiation of retinal photoreceptors and modulate adaptive response during aging. Then, we discuss NGS technology in the context of retinal disease and develop a vision for therapies based on network biology. We should emphasize that basic strategies for network construction and analyses can be transported to any tissue or cell type. We believe that specific and uniform guidelines are required for generation of genome, transcriptome and epigenome data to facilitate comparative analysis and integration of multi-dimensional data sets, and for constructing networks underlying complex biological processes. As cellular homeostasis and organismal survival are dependent on gene-gene and gene-environment interactions, we believe that network-based biology will provide the foundation for deciphering disease mechanisms and discovering novel drug targets for retinal neurodegenerative diseases. Copyright © 2015. Published by Elsevier Ltd.
    Progress in Retinal and Eye Research 02/2015; 46. DOI:10.1016/j.preteyeres.2015.01.005 · 8.73 Impact Factor
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    ABSTRACT: Retinal neurodegeneration associated with the dysfunction or death of photoreceptors is a major cause of incurable vision loss. Tremendous progress has been made over the last two decades in discovering genes and genetic defects that lead to retinal diseases. The primary focus has now shifted to uncovering disease mechanisms and designing treatment strategies, especially inspired by the successful application of gene therapy in some forms of congenital blindness in humans. Both spontaneous and laboratory-generated mouse mutants have been valuable for providing fundamental insights into normal retinal development and for deciphering disease pathology. Here, we provide a review of mouse models of human retinal degeneration, with a primary focus on diseases affecting photoreceptor function. We also describe models associated with retinal pigment epithelium dysfunction or synaptic abnormalities. Furthermore, we highlight the crucial role of mouse models in elucidating retinal and photoreceptor biology in health and disease, and in the assessment of novel therapeutic modalities, including gene- and stem-cell-based therapies, for retinal degenerative diseases. © 2015. Published by The Company of Biologists Ltd.
    Disease Models and Mechanisms 02/2015; 8(2):109-129. DOI:10.1242/dmm.017913 · 4.97 Impact Factor
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    ABSTRACT: Purpose: The Israeli population has a unique genetic make-up, with a high prevalence of consanguineous marriages and autosomal recessive diseases. In rod-dominated phenotypes, disease-causing genes and mutations that differ from those identified in other populations are often incurred. Here we use whole exome sequencing (WES) to identify genetic defects in Israeli families with cone-dominated retinal phenotypes. Methods: Clinical analysis included family history, detailed ocular examination, visual function testing and retinal imaging. WES, followed by segregation analysis, was performed in 6 cone-dominated retinopathy families in which prior mutation analysis did not reveal the causative gene. Based on the WES findings, we screened 106 additional families with cone-dominated phenotypes. Results: WES analysis revealed mutations in known retinopathy genes in five out of the six families: two pathogenic mutations in the GUCY2D gene in three families, and one each in CDHR1 and C8orf37. Targeted screening of additional cone-dominated families led to identification of GUCY2D mutations in four other families, which included two highly probable novel disease-causing variants. Conclusions: Our study suggest that GUCY2D is a major cause of autosomal dominant cone- and cone-rod dystrophies in Israel; this is similar to other Caucasian populations and is in contrast to retinitis pigmentosa (primary rod disease) where the genetic make-up of the Israeli population is distinct from other ethnic groups. We also conclude that WES permits more comprehensive and rapid analyses that can be followed by targeted screens of larger samples to delineate the genetic structure of retinal disease in unique population cohorts. Copyright © 2014 by Association for Research in Vision and Ophthalmology.
    Investigative Ophthalmology &amp Visual Science 12/2014; 56(1). DOI:10.1167/iovs.14-15647 · 3.40 Impact Factor
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    ABSTRACT: Neural retina leucine zipper (NRL) is an essential transcription factor for cell fate specification and functional maintenance of rod photoreceptors in the mammalian retina. In the Nrl�/� mouse retina, photoreceptor precursors fail to produce rods and generate functional cone photoreceptors that predominantly express S-opsin. Previous global expression analysis using microarrays revealed dramatically reduced expression of myocyte enhancer factor Mef2c in the adult Nrl�/� retina. We undertook this study to examine the biological relevance of Mef2c expression in retinal rod photoreceptors. Bioinformatics analysis, rapid analysis of cDNA ends (5�-RACE), and reverse transcription coupled with qPCR using splice site-specific oligonucleotides suggested that Mef2c is expressed in the mature retina from an alternative promoter. Chromatin immunoprecipitation (ChIP) studies showed the association of active RNA polymerase II and acetylated histone H3 just upstream of Mef2c exon 4, providing additional evidence for the utilization of an alternative promoter in the retina. In concordance, we observed the binding of NRL to a putative NRL-response element (NRE) at this location by ChIP-seq and electrophoretic mobility shift assays. NRL also activated the Mef2c alternative promoter in vitro and in vivo. Notably,MEF2Ccould support Rhodopsin promoter activity in rod photoreceptors. We conclude that Mef2c expression from an alternative promoter in the retina is regulated by NRL. Our studies also implicate MEF2C as a transcriptional regulator of homeostasis in rod photoreceptor cells.
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    ABSTRACT: The mechanisms that specify photoreceptor cell-fate determination, especially as regards to short-wave-sensitive (S) versus medium-wave-sensitive (M) cone identity, and maintain their nature and function, are not fully understood. Here we report the importance of general transcription factor II-I repeat domain-containing protein 1 (GTF2IRD1) in maintaining M cone cell identity and function as well as rod function. In the mouse, GTF2IRD1 is expressed in cell-fate determined photoreceptors at postnatal day 10. GTF2IRD1 binds to enhancer and promoter regions in the mouse rhodopsin, M- and S-opsin genes, but regulates their expression differentially. Through interaction with the transcription factors CRX and thyroid hormone receptor β 2, it enhances M-opsin expression, whereas it suppresses S-opsin expression; and with CRX and NRL, it enhances rhodopsin expression. In an apparent paradox, although GTF2IRD1 is widely expressed in multiple cell types across the retina, knock-out of GTF2IRD1 alters the retinal expression of only a limited number of annotated genes. Interestingly, however, the null mutation leads to altered topology of cone opsin expression in the retina, with aberrant S-opsin overexpression and M-opsin underexpression in M cones. Gtf2ird1-null mice also demonstrate abnormal M cone and rod electrophysiological responses. These findings suggest an important role for GTF2IRD1 in regulating the level and topology of rod and cone gene expression, and in maintaining normal retinal function.
    The Journal of Neuroscience : The Official Journal of the Society for Neuroscience 11/2014; 34(46):15356-68. DOI:10.1523/JNEUROSCI.2089-14.2014 · 6.34 Impact Factor
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    ABSTRACT: Objective To determine whether genotypes at 2 major loci associated with late age-related macular degeneration (AMD), complement factor H (CFH) and age-related maculopathy susceptibility 2 (ARMS2), influence the relative benefits of Age-Related Eye Disease Study (AREDS) supplements. Design Unplanned retrospective evaluation of a prospective, randomized, placebo-controlled clinical trial of vitamins and minerals for the treatment of AMD. Subjects AREDS participants (mean age, 69 years) who were at risk of developing late AMD and who were randomized to the 4 arms of AREDS supplement treatment. Methods Analyses were performed using the Cox proportional hazards model to predict progression to late AMD (neovascular or central geographic atrophy). Statistical models, adjusted for age, gender, smoking status, and baseline AMD severity, were used to examine the influence of genotypes on the response to therapy with 4 randomly assigned arms of AREDS supplement components: placebo, antioxidants (vitamin C, vitamin E, β-carotene), zinc or a combination. Main Outcome Measures The influence of the genotype on the relative treatment response to the randomized components of the AREDS supplement, measured as progression to late AMD. Results Of the 1237 genotyped AREDS participants of white ethnicity, late AMD developed in 385 (31.1%) during the mean follow-up of 6.6 years. As previously demonstrated, CFH genotype (P = 0.005), ARMS2 (P< 0.0001), and supplement were associated individually with progression to late AMD. An interaction analysis found no evidence that the relative benefits of AREDS supplementation varied by genotype. Analysis of (1) CFH rs1061170 and rs1410996 combined with ARMS2 rs10490924 with the 4 randomly assigned arms of AREDS supplement and (2) analysis of the combination of CFH rs412852 and rs3766405 with ARMS2 c.372_815del443ins54 with the AREDS components resulted in no interaction (P = 0.06 and P = 0.45, respectively, before multiplicity adjustment). Conclusions The AREDS supplements reduced the rate of AMD progression across all genotype groups. Furthermore, the genotypes at the CFH and ARMS2 loci did not statistically significantly alter the benefits of AREDS supplements. Genetic testing remains a valuable research tool, but these analyses suggest it provides no benefits in managing nutritional supplementation for patients at risk of late AMD.
    Ophthalmology 11/2014; 121(11). DOI:10.1016/j.ophtha.2014.05.008 · 6.14 Impact Factor
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    ABSTRACT: Vision requires the generation of cone and rod photoreceptors that function in daylight and dim light, respectively. The neural retina leucine zipper factor (NRL) transcription factor critically controls photoreceptor fates as it stimulates rod differentiation and suppresses cone differentiation. However, the controls over NRL induction that balance rod and cone fates remain unclear. We have reported previously that the retinoid-related orphan receptor β gene (Rorb) is required for Nrl expression and other retinal functions. We show that Rorb differentially expresses two isoforms: RORβ2 in photoreceptors and RORβ1 in photoreceptors, progenitor cells, and other cell types. Deletion of RORβ2 or RORβ1 increased the cone:rod ratio ∼2-fold, whereas deletion of both isoforms in Rorb−/− mice produced almost exclusively cone-like cells at the expense of rods, suggesting that both isoforms induce Nrl. Electroporation of either RORβ isoform into retinal explants from Rorb−/− neonates reactivated Nrl and rod genes but, in Nrl−/− explants, failed to reactivate rod genes, indicating that NRL is the effector for both RORβ isoforms in rod differentiation. Unexpectedly, RORβ2 expression was lost in Nrl−/− mice. Moreover, NRL activated the RORβ2-specific promoter of Rorb, indicating that NRL activates Rorb, its own inducer gene. We suggest that feedback activation between Nrl and Rorb genes reinforces the commitment to rod differentiation.
    Journal of Biological Chemistry 10/2014; 289(47). DOI:10.1074/jbc.M114.605774 · 4.57 Impact Factor
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    ABSTRACT: Planar cell polarity (PCP) signaling plays a critical role in tissue morphogenesis. In mammals, disruption of three of the six ‘‘core PCP’’ components results in polarity-dependent defects with rotated cochlear hair cell stereocilia and open neural tube. We recently demonstrated a role of Prickle1, a core PCP molecule in Drosophila, in mammalian neuronal development. To examine Prickle1function along a broader developmental window, we generated three mutant alleles in mice. We show that the complete loss of Prickle1 leads to systemic tissue outgrowth defects, aberrant cell organization and disruption of polarity machinery. Curiously, Prickle1 mutants recapitulate the characteristic features of human Robinow syndrome and phenocopy mouse mutants with Wnt5a or Ror2 gene defects, prompting us to explore an association of Prickle1 with the Wnt pathway. We show that Prickle1 is a proteasomal target of Wnt5a signaling and that Dvl2, a target of Wnt5a signaling, is misregulated in Prickle1 mutants. Our studies implicate Prickle1 as a key component of the Wnt-signaling pathway and suggest that Prickle1 mediates some of the WNT5A-associated genetic defects in Robinow syndrome
    Biology Open 09/2014; 3(9):861-870. DOI:10.1242/bio.20148375 · 2.42 Impact Factor
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    ABSTRACT: Purpose: The aryl hydrocarbon receptor (AHR) is a ligand-activated nuclear receptor that regulates cellular response to environmental signals, including UV and blue wavelength light. This study was undertaken to elucidate AHR function in retinal homeostasis. Methods: RNA-seq data sets were examined for Ahr expression in the mouse retina and rod photoreceptors. The Ahr(-/-) mice were evaluated by fundus imaging, optical coherence tomography, histology, immunohistochemistry, and ERG. For light damage experiments, adult mice were exposed to 14,000 to 15,000 lux of diffuse white light for 2 hours. Results: In mouse retina, Ahr transcripts were upregulated during development, with continued increase in aging rod photoreceptors. Fundus examination of 3-month-old Ahr(-/-) mice revealed subretinal autofluorescent spots, which increased in number with age and following acute light exposure. Ahr(-/-) retina also showed subretinal microglia accumulation that correlated with autofluorescence changes, RPE abnormalities, and reactivity against immunoglobulin, complement factor H, and glial fibrillary acidic protein. Functionally, Ahr(-/-) mice displayed reduced ERG c-wave amplitudes. Conclusions: The Ahr(-/-) mice exhibited subretinal accumulation of microglia and focal RPE atrophy, phenotypes observed in AMD. Together with a recently published report on another Ahr(-/-) mouse model, our study suggests that AHR has a protective role in the retina as an environmental stress sensor. As such, its altered function may contribute to human AMD progression and provide a target for pharmacological intervention.
    Investigative Ophthalmology &amp Visual Science 08/2014; 55(9). DOI:10.1167/iovs.14-15091 · 3.40 Impact Factor
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    ABSTRACT: The primary cilium originates from the mother centriole and participates in critical functions during organogenesis. Defects in cilia biogenesis or function lead to pleiotropic phenotypes. Mutations in centrosome-cilia gene CC2D2A result in Meckel and Joubert syndromes. Here we generate a Cc2d2a(-/-) mouse that recapitulates features of Meckel syndrome including embryonic lethality and multiorgan defects. Cilia are absent in Cc2d2a(-/-) embryonic node and other somatic tissues; disruption of cilia-dependent Shh signalling appears to underlie exencephaly in mutant embryos. The Cc2d2a(-/-) mouse embryonic fibroblasts (MEFs) lack cilia, although mother centrioles and pericentriolar proteins are detected. Odf2, associated with subdistal appendages, is absent and ninein is reduced in mutant MEFs. In Cc2d2a(-/-) MEFs, subdistal appendages are lacking or abnormal by transmission electron microscopy. Consistent with this, CC2D2A localizes to subdistal appendages by immuno-EM in wild-type cells. We conclude that CC2D2A is essential for the assembly of subdistal appendages, which anchor cytoplasmic microtubules and prime the mother centriole for axoneme biogenesis.
    Nature Communications 06/2014; 5:4207. DOI:10.1038/ncomms5207 · 11.47 Impact Factor

Publication Stats

12k Citations
1,824.45 Total Impact Points


  • 2009–2015
    • National Institutes of Health
      • Laboratory of Neurobiology-Neurodegeneration and Repair
      베서스다, Maryland, United States
  • 2008–2014
    • National Eye Institute
      Maryland, United States
    • University of California, San Diego
      San Diego, California, United States
  • 1992–2014
    • University of Michigan
      • • Department of Human Genetics
      • • Department of Ophthalmology and Visual Sciences
      • • Department of Psychology
      Ann Arbor, Michigan, United States
  • 2010–2013
    • NEI Corporation
      Сомерсет, New Jersey, United States
  • 2011
    • University of Massachusetts Medical School
      • Department of Ophthalmology
      Worcester, Massachusetts, United States
  • 2007
    • Champalimaud Neuroscience Program
      Lisboa, Lisbon, Portugal
  • 2002
    • University of Pennsylvania
      • Scheie Eye Institute
      Philadelphia, Pennsylvania, United States
  • 1999
    • University of Houston
      • Department of Biology and Biochemistry
      Houston, TX, United States
    • Johns Hopkins University
      • Department of Molecular Biology and Genetics
      Baltimore, Maryland, United States
  • 1997–1998
    • Lund University
      • Department of Ophthalmology
      Lund, Skane, Sweden
  • 1995
    • Massachusetts Institute of Technology
      • Department of Biology
      Cambridge, MA, United States
  • 1985–1995
    • Yale University
      • • Department of Genetics
      • • Department of Molecular Biophysics and Biochemistry
      New Haven, Connecticut, United States
  • 1991
    • Stanford Medicine
      Stanford, California, United States
  • 1990
    • Howard Hughes Medical Institute
      Ашбърн, Virginia, United States
  • 1988–1990
    • Yale-New Haven Hospital
      New Haven, Connecticut, United States