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Shoji Kishi - One of the best experts on this subject based on the ideXlab platform.

  • Restored Photoreceptor Outer Segment in commotio retinae.
    Ophthalmic surgery lasers & imaging : the official journal of the International Society for Imaging in the Eye, 2011
    Co-Authors: Hirotaka Itakura, Shoji Kishi
    Abstract:

    The authors report the retinal findings of the healing phase in commotio retinae. Retinal images were obtained using spectral-domain optical coherence tomography (SD-OCT) on 3 eyes from 3 patients with commotio retinae after blunt ocular trauma. The best-corrected visual acuity (BCVA) and fundus appearance from the medical records were retrospectively studied. All cases had commotio retinae in the posterior pole. OCT showed increased reflectivity of the line at the junction between the Photoreceptor inner and Outer Segments (IS/OS) in the area of the opacified retina in all cases. The initial BCVA in cases 1, 2, and 3 was 1.5, 1.2, and 0.7, respectively. In all eyes, the neurosensory retinal edema had resolved and the IS/OS line returned to normal architecture. The final BCVA in cases 1, 2, and 3 was 2.0, 1.5, and 1.5, respectively. The authors found restored Photoreceptor Outer Segment in commotio retinae by SD-OCT and improvement of BCVA.

  • restoration of Photoreceptor Outer Segment after vitrectomy for retinal detachment
    American Journal of Ophthalmology, 2010
    Co-Authors: Yukitoshi Shimoda, Morihiko Sano, Hideaki Hashimoto, Yukihiro Yokota, Shoji Kishi
    Abstract:

    Purpose To report Photoreceptor restoration and visual outcomes after vitrectomy for retinal detachment. Design Retrospective, observational case series. Methods We prospectively studied the tomographic features of reattached retinas in 20 eyes with a macula-off rhegmatogenous retinal detachment using spectral-domain optical coherence tomography 1, 3, and 6 months after 3-port vitrectomy with SF 6 gas tamponade. All eyes were examined more than 3 months after surgery. Results The optical coherence tomography foveal findings were classified as a disrupted inner Segment and Outer Segment (IS/OS) line, a residual foveal detachment, and a continuous IS/OS line. A disrupted IS/OS line was seen in 11 eyes (55%) at 1 month and in 8 eyes (40%) at 3 months, a foveal detachment was seen in 8 eyes (40%) at 1 month and in 7 eyes (35%) at 3 months, and a continuous IS/OS line was seen in 1 eye (5%) at 1 month and in 5 eyes (25%) at 3 months. In 18 eyes followed up for 6 months, optical coherence tomography showed a disrupted IS/OS line in 3 eyes (17%), a foveal detachment in 6 eyes (33%), and a continuous IS/OS line in 9 eyes (50%). The mean best-corrected visual acuities at 1 and 6 months were 0.26 and 0.16 with a disrupted IS/OS line, 0.60 and 0.95 with a foveal detachment, and 0.8 and 0.95 with a continuous IS/OS line. The mean best-corrected visual acuity was significantly ( P Conclusions The IS/OS line at the fovea recovered gradually after surgery. The postoperative visual acuity was correlated with a restored IS/OS line.

  • restored Photoreceptor Outer Segment damage in multiple evanescent white dot syndrome
    Ophthalmology, 2009
    Co-Authors: Danjie Li, Shoji Kishi
    Abstract:

    Purpose To report retinal tomography and function in the course of multiple evanescent white dot syndrome (MEWDS). Design Prospective case series. Participants Seven patients with unilateral MEWDS. Methods We performed optical coherence tomography (OCT), multifocal electroretinography (mfERG), full-field electroretinography (ffERG), fluorescein and indocyanine green angiography, and visual field examinations in 7 patients with active to resolved MEWDS. Main Outcome Measures OCT imaging of the posterior fundus with a 6×6-mm square, best-corrected visual acuity (BCVA), fundus characteristics, visual field measurements, mfERG, and ffERG responses. Results All patients reported unilateral blurred vision and spotty visual field defects. The fundi had yellow or white dots of various sizes and extent in the affected eyes. The visual fields had enlarged blind spots in all affected eyes and scotomas in 3 of the 7 eyes. In 5 of the all fellow eyes, 4 fellow eyes had an enlarged blind spot, peripheral visual field defects, or both; 1 eye had only a peripheral field defect. OCT showed a disrupted or irregular Photoreceptor inner/Outer Segment (IS/OS) junction line of varied extent in 7 affected eyes and 1 fellow eye. During 1.5 weeks to 6 months follow-up (mean, 3.4 months), the BCVA returned to 1.2 along with resolution of the white dots in all eyes. The IS/OS line was restored in 7 eyes, but 1 eye had focal disruption. The visual fields returned to normal in 5 affected eyes; however, an enlarged blind spot remained in 2 affected eyes and a peripheral defect remained in 2 fellow eyes. On ffERG and mfERG, the decreased responses recovered markedly in the 7 affected eyes. Conclusions The lesions responsible for MEWDS appear to disrupt the Photoreceptor Outer Segments; morphologic and functional recovery can occur. Although the symptoms and fundus lesions were visible unilaterally, the Photoreceptor dysfunction was bilateral in most cases. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

  • restored Photoreceptor Outer Segment and visual recovery after macular hole closure
    American Journal of Ophthalmology, 2009
    Co-Authors: Morihiko Sano, Yukitoshi Shimoda, Hideaki Hashimoto, Shoji Kishi
    Abstract:

    Purpose To evaluate restoration of the Photoreceptor Outer Segment and visual outcomes in closed macular holes. Design Retrospective case series. Methods We retrospectively observed the reparative process of macular holes in 28 eyes one, three, and six months postoperatively using spectral-domain optical coherence tomography. We evaluated the reflective line at the junction between the Photoreceptor inner and Outer Segment (IS/OS) and the best-corrected visual acuity (BCVA). Results The Outer Photoreceptor layer showed a foveal detachment, a disrupted IS/OS line, or both one month postoperatively. No eye had a continuous IS/OS line. These abnormalities were gradually restored at various levels. At six months, nine eyes had a normal Outer Photoreceptor layer, four eyes Outer foveal defects with a continuous IS/OS line, 12 eyes a disrupted IS/OS line, and three eyes Outer foveal defects with a disrupted IS/OS line. The mean BCVAs were significantly ( P = .017) lower in groups with a disrupted IS/OS line compared to groups with a continuous IS/OS line with or without Outer foveal defects. Conclusions Macular hole closure is attained by bridge formation (foveal detachment) and the IS/OS line heals in varying degrees. The visual outcomes were significantly better in eyes with a continuous IS/OS line than in those with a disrupted IS/OS line.

  • elongation of Photoreceptor Outer Segment in central serous chorioretinopathy
    American Journal of Ophthalmology, 2008
    Co-Authors: Hidetaka Matsumoto, Shoji Kishi, Tetsuya Otani, Taku Sato
    Abstract:

    Purpose To investigate Photoreceptor Segment morphologic changes at the detached retina in central serous chorioretinopathy (CSC). Design Observational case series. Methods We measured and compared the distance between the internal limiting membrane (ILM) and the external limiting membrane (ELM), between the ELM and the Photoreceptor inner and Outer Segment junction (IS/OS) at the central fovea, and the length of the longest Outer Segment in 20 consecutive CSC eyes and 10 normal eyes on Fourier domain optical coherence tomography (FD-OCT) images. We evaluated the correlation between the length of the Outer Segment and age, best-corrected visual acuity (BCVA), and symptom duration in CSC eyes and the correlation between retinal thickness from the ILM to ELM and the other parameters. Results The median distance between the ILM and ELM was 75 μm in the CSC eyes and was significantly ( P = .0001) shorter than the median 135 μm in normal eyes. The median distance between the ELM and IS/OS was 35 μm in normal eyes and CSC eyes. The median longest Outer Segment length in CSC eyes was 90 μm and was significantly ( P = .01) longer than the 60 μm in normal eyes. The Outer Segment length was not or weakly correlated with age ( r s = 0.38), BCVA ( r s = 0.09), or symptom duration ( r s = 0.19). The distance between the ILM and ELM was weakly correlated with age ( r s = 0.34), BCVA ( r s = 0.34), or symptom duration ( r s = 0.28). Conclusions FD-OCT showed elongation of Photoreceptor Outer Segments and decreased thickness of the Outer nuclear layer in CSC.

Nagahisa Yoshimura - One of the best experts on this subject based on the ideXlab platform.

Brian D Perkins - One of the best experts on this subject based on the ideXlab platform.

  • the ciliopathy gene ahi1 is required for zebrafish cone Photoreceptor Outer Segment morphogenesis and survival
    Investigative Ophthalmology & Visual Science, 2017
    Co-Authors: Ping Song, Joseph Fogerty, Robert J Gaivin, Brian D Perkins, Emma M Lessieur
    Abstract:

    Purpose Joubert syndrome (JBTS) is an autosomal recessive ciliopathy with considerable phenotypic variability. In addition to central nervous system abnormalities, a subset of JBTS patients exhibit retinal dystrophy and/or kidney disease. Mutations in the AHI1 gene are causative for approximately 10% of all JBTS cases. The purpose of this study was to generate ahi1 mutant alleles in zebrafish and to characterize the retinal phenotypes.

  • arl13b interacts with vangl2 to regulate cilia and Photoreceptor Outer Segment length in zebrafish
    Investigative Ophthalmology & Visual Science, 2016
    Co-Authors: Ping Song, Lynn Dudinsky, Joseph Fogerty, Robert J Gaivin, Brian D Perkins
    Abstract:

    Purpose Mutations in the gene ARL13B cause the classical form of Joubert syndrome, an autosomal recessive ciliopathy with variable degrees of retinal degeneration. As second-site modifier alleles can contribute to retinal pathology in ciliopathies, animal models provide a unique platform to test how genetic interactions modulate specific phenotypes. In this study, we analyzed the zebrafish arl13b mutant for retinal degeneration and for epistatic relationships with the planar cell polarity protein (PCP) component vangl2.

  • early defects in Photoreceptor Outer Segment morphogenesis in zebrafish ift57 ift88 and ift172 intraflagellar transport mutants
    Vision Research, 2009
    Co-Authors: Sujita Sukumaran, Brian D Perkins
    Abstract:

    Abstract Intraflagellar Transport (IFT) refers to a highly conserved process occurring in eukaryotic ciliated structures. In vertebrate Photoreceptors, IFT mediates protein trafficking to the Outer Segments. The IFT particle is a multi-subunit complex and mutations in many individual components causes Photoreceptor defects. In zebrafish, mutations in the ift57 , ift88 , and ift172 genes result in retinal degeneration by 5 days post fertilization (dpf). Although the effects of these mutations on Photoreceptor survival have been described, early developmental morphogenesis remains poorly understood. We used transmission electron microscopy and immunohistochemistry to examine these mutants at 60, 72, and 96 h post fertilization (hpf) and describe early Photoreceptor morphogenesis defects.

Janet R Sparrow - One of the best experts on this subject based on the ideXlab platform.

  • photooxidation of a2 pe a Photoreceptor Outer Segment fluorophore and protection by lutein and zeaxanthin
    Experimental Eye Research, 2006
    Co-Authors: Koji Nakanishi, Yasuhiro Itagaki, Janet R Sparrow
    Abstract:

    Abstract A2-PE is a pigment that forms as a byproduct of the visual cycle, its synthesis from all- trans -retinal and phosphatidylethanolamine occurring in Photoreceptor Outer Segments. A2-PE is deposited in retinal pigment epithelial (RPE) cells secondary to phagocytosis of shed Outer Segment membrane and it undergoes hydrolysis to generate the RPE lipofuscin fluorophores, A2E, iso-A2E and other minor cis -isomers of A2E. We have demonstrated that A2-PE can initiate photochemical processes that involve the oxidation of A2-PE and that, by analogy with A2E are likely to include the formation of reactive moieties. We also show that potential sources of protection against the photooxidation of A2-PE are the lipid-soluble carotenoids zeaxanthin and lutein (xanthophylls), that constitute the yellow pigment of the macula. Irradiation of A2-PE in the presence of lutein or zeaxanthin suppressed A2-PE photooxidation and in experiments in which we compared the antioxidant capability of zeaxanthin and lutein to α-tocopherol, the carotenoids were more potent. Additionally, the effect with zeaxanthin was consistently more robust than with lutein and when α-tocopherol was combined with either carotenoid, the outcome was additive. Lutein, zeaxanthin and α-tocopherol were all efficient quenchers of singlet oxygen. We have also shown that lutein and zeaxanthin can protect against A2-PE/A2E photooxidation without appreciable consumption of the carotenoid by chemical reaction. This observation contrasts with the pronounced susceptibility of A2E and A2-PE to photooxidation and is of interest since lutein, zeaxanthin, A2E and A2-PE all have conjugated systems of carbon–carbon double bonds terminating in cyclohexenyl end-groups. The structural features responsible for the differences in quenching mechanisms are discussed. It has long been suspected that macular pigment protects the retina both by filtering high-energy blue light and by serving an antioxidant function. Evidence presented here suggests that the photochemical reactions against which lutein and zeaxanthin protect, may include those initiated by the A2-PE. Quantitative HPLC analysis revealed that in eyecups of C57BL/6J and BALB/cByJ mice, levels of A2-PE were several fold greater than the cleavage product, A2E. Taken together, these results may have implications with respect to the involvement of A2-PE formation in mechanisms underlying blue light-induced Photoreceptor cell damage and may be significant to retinal degenerative disorders, such as those associated with ABCA4 mutations, wherein there is a propensity for increased A2-PE synthesis.

  • the biosynthesis of a2e a fluorophore of aging retina involves the formation of the precursor a2 pe in the Photoreceptor Outer Segment membrane
    Journal of Biological Chemistry, 2000
    Co-Authors: Yasuhiro Itagaki, Shimon Benshabat, Koji Nakanishi, Janet R Sparrow
    Abstract:

    Abstract The autofluorescent lipofuscin that accumulates in retinal pigment epithelial cells with age may contribute to an age-related decline in cell function. The major lipofuscin fluorophore, A2E, is a pyridinium bisretinoid. We previously proposed that the biogenesis of A2E involves the following: (i) formation of the Schiff base, N-retinylidene phosphatidylethanolamine from all-trans-retinal and phosphatidylethanolamine in the Photoreceptor Outer Segment membrane; (ii) further reaction ofN-retinylidene phosphatidylethanolamine with retinal to yield phosphatidylethanolamine-bisretinoid, A2-PE; (iii) hydrolysis of A2-PE to generate A2E. To provide evidence for this biogenic scheme, all-trans-retinal was reacted with dipalmitoyl-l-α-phosphatidylethanolamine to yield DP-A2-PE (A2-PE), as confirmed by UV, with mass spectrometry revealing the molecular ion at m/z 1222.9 (C77H124O8PN) accompanied by product ion at m/z 672.8, representing the phosphoryl-A2E fragment of A2-PE. In reaction mixtures of retinal and Outer Segments and in samples of Royal College of Surgeons rat retina containing Outer Segment membranous debris, A2-PE was detected as a series of high performance liquid chromatography peaks, each with UV similar to reference A2-PE. By mass spectrometry, A2-PE consisted of multiple peaks, representing fatty acids with different chain lengths, and the phosphoryl-A2E moiety, m/z 673. Incubation of the retinal/Outer Segment reaction mixture with phospholipase D generated A2E, as detected by high performance liquid chromatography, thus confirming A2-PE as the A2E precursor.

Muayyad R Alubaidi - One of the best experts on this subject based on the ideXlab platform.

  • oligomerization of prph2 and rom1 is essential for Photoreceptor Outer Segment formation
    Human Molecular Genetics, 2018
    Co-Authors: Rahel Zulliger, Muayyad R Alubaidi, Shannon M Conley, Maggie L Mwoyosvi, Muna I Naash
    Abstract:

    Mutations in peripherin 2 (PRPH2, also known as Rds), a tetraspanin protein found in Photoreceptor Outer Segments (OSs), cause retinal degeneration ranging from rod-dominant retinitis pigmentosa (RP) to cone-dominant macular dystrophy (MD). Understanding why some Prph2 mutants affect rods while others affect cones remains a critical unanswered question. Prph2 is essential for OS structure and function and exhibits a very specific pattern of oligomerization with its homolog Rom1. Non-covalent Prph2/Rom1 homo- and hetero-tetramers assemble into higher-order covalently linked complexes held together by an intermolecular disulfide bond at Prph2-C150/Rom1-C153. Here we disrupt this crucial bond using a C150S-Prph2 knockin mouse line to study the role of Prph2 higher-order complex formation. We find that C150S-Prph2 traffics to the OS, interacts with Rom1 and forms non-covalent tetramers, but alone cannot support normal OS structure and function. However, C150S-Prph2 supports the initiation or elaboration of OS disc structures, and improves rod OS ultrastructure in the presence of wild-type (WT) Prph2 (i.e. Prph2C150S/+ versus Prph2+/−). Prph2C150S/+ animals exhibit haploinsufficiency in rods, but a dominant-negative phenotype in cones, suggesting cones have a different requirement for large Prph2 complexes than rods. Importantly, cone but not rod function can be improved by the addition of one Prph2Y141C allele, a mutation responsible for pattern dystrophy owing to the extra cysteine. Combined these findings show that covalently linked Prph2 complexes are essential for OS formation, but not for Prph2 targeting to the OS, and that cones are especially sensitive to having a broad distribution of Prph2 complex types (i.e. tetramers and large complexes).

  • glycosylation of rhodopsin is necessary for its stability and incorporation into Photoreceptor Outer Segment discs
    Human Molecular Genetics, 2015
    Co-Authors: Anne Murray, Muna I Naash, Steven J Fliesler, Linda Vuong, Daniel Brobst, Neal S Peachey, Marina S Gorbatyuk, Muayyad R Alubaidi
    Abstract:

    Rhodopsin, a G-protein coupled receptor, most abundant protein in retinal rod Photoreceptors, is glycosylated at asparagines-2 and 15 on its N-terminus. To understand the role of rhodopsin's glycosylation in vivo, we generated and characterized a transgenic mouse model that expresses a non-glycosylated form of rhodopsin. We show that lack of glycosylation triggers a dominant form of progressive retinal degeneration. Electron microscopic examination of retinas at postnatal day 17 revealed the presence of vacuolar structures that distorted rod Photoreceptor Outer Segments and became more prominent with age. Expression of non-glycosylated rhodopsin alone showed that it is unstable and is regulated via ubiquitin-mediated proteasomal degradation at the base of Outer Segments. We observed similar vacuolization in Outer Segments of transgenic mice expressing human rhodopsin with a T17M mutation (hT17M), suggesting that the mechanism responsible for the degenerative process in mice expressing the non-glycosylated rhodopsin and the RHOhT17M mice is likely the cause of phenotype observed in retinitis pigmentosa patients carrying T17M mutation.

  • rim formation is not a prerequisite for distribution of cone Photoreceptor Outer Segment proteins
    The FASEB Journal, 2014
    Co-Authors: Shannon M Conley, Muayyad R Alubaidi, Muna I Naash
    Abstract:

    Retinal degeneration slow (RDS/PRPH2) is critical for the formation of the disc/lamella rim in Photoreceptor Outer Segments (OSs), but plays a different role in rods vs. cones. Without RDS, rods fail to form OSs, however, cones lacking RDS (in the rds−/−/Nrl−/−) exhibit balloon-like OSs devoid of lamellae. We show that distribution of most proteins in the lamella and PM domains is preserved even in the absence of RDS, rim, and lamella structures. However, the rim protein prominin-1 exhibits altered trafficking and OS localization, suggesting that proper targeting and distribution of rim proteins may require RDS. Our ultrastructural studies show that in cones, OS formation is initiated by the growth of opsin-containing membrane with RDS-mediated rim formation as a secondary step. This is directly opposite to rods and significantly advances our understanding of the role of the rim in cone OS morphogenesis. Furthermore, our results suggest that the unique folded lamella architecture of the cone OS may maximi...

  • lack of protein tyrosine sulfation disrupts Photoreceptor Outer Segment morphogenesis retinal function and retinal anatomy
    European Journal of Neuroscience, 2010
    Co-Authors: David M Sherry, Anne Murray, Yogita Kanan, Kelsey L Arbogast, Robert A Hamilton, Steven J Fliesler, Marie E Burns, Kevin L Moore, Muayyad R Alubaidi
    Abstract:

    To investigate the role(s) of protein-tyrosine sulfation in the retina, we examined retinal function and structure in mice lacking tyrosylprotein sulfotransferases (TPST) 1 and 2. Tpst double knockout (DKO; Tpst1 -/- /Tpst2 -/- ) retinas had drastically reduced electroretinographic responses, although their Photoreceptors exhibited normal responses in single cell recordings. These retinas appeared normal histologically; however, the rod Photoreceptors had ultrastructurally abnormal Outer Segments, with membrane evulsions into the extracellular space, irregular disc membrane spacing and expanded intradiscal space. Photoreceptor synaptic terminals were disorganized in Tpst DKO retinas, but established ultrastructurally normal synapses, as did bipolar and amacrine cells; however, the morphology and organization of neuronal processes in the inner retina were abnormal. These results indicate that protein-tyrosine sulfation is essential for proper Outer Segment morphogenesis and synaptic function, but is not critical for overall retinal structure or synapse formation, and may serve broader functions in neuronal development and maintenance.

  • Photoreceptor Outer Segment development in xenopus laevis influence of the pigment epithelium
    Developmental Biology, 1994
    Co-Authors: Monica M Stiemke, R A Landers, Muayyad R Alubaidi, Mary E Rayborn, Joe G Hollyfield
    Abstract:

    Abstract Opsin gene expression, synthesis, and Photoreceptor Outer Segment morphology were evaluated during retinal development in Xenopus laevis . Retinal rudiments were harvested during in vivo development from embryonic stages 31 through 46 or were allowed to develop in vitro after removal from stage 33/34 embryos for 1, 2, or 3 days either with or without an investing pigment epithelium. Opsin mRNA was detected at stage 33/34 and the transcript level increased until stage 40 and remained at this level through stage 46. Opsin was first detected at stage 37/38 and progressively increased through stage 46. Rudimentary Photoreceptor Outer Segment membranes occasionally appeared as early as stage 33/34 and they gradually increased in length, forming well-defined stacks of collapsed membranous saccules (discs) during in vivo development. The maturation of eye rudiments in culture was followed to determine how closely in vivo and in vitro development compare and to examine the ability of Photoreceptors to differentiate when maintained in the absence of an overlying pigment epithelium (PE) layer. With the PE present, opsin mRNA as well as opsin content steadily increased over the entire culture period. After 1 day of culture, short cilia with minimal amounts of Outer Segment membranous material were present. By Day 3, the degree of Outer Segment differentiation corresponded morphologically to approximately stage 43 of in vivo development. When cultured in the absence of an investing PE, the opsin mRNA level increased minimally during the 3 days in culture. Opsin content increased, yet the relative amount was approximately 50% less than that present in retinas developing in the presence of the PE. Membranous material was elaborated; however, the Outer Segments appeared to be highly disorganized and formed whorl-like structures rather than the normal stacked disc morphology. These results suggest that the PE may be involved in regulating opsin at the transcriptional and/or translational levels and also participates in the organization of rod Outer Segment membranes.