Electron-microscopic and morphometric investigation of the action of enkad on retinal photoreceptor cells of campbell rats with hereditary retinal degeneration

1990 ◽  
Vol 109 (5) ◽  
pp. 669-672
Author(s):  
O. G. Stroeva ◽  
V. A. Poplinskaya ◽  
I. G. Panova ◽  
I. P. Khoroshilova-Maslova
Keyword(s):  
Retinal Degeneration ◽  
Photoreceptor Cells ◽  
Electron Microscopic ◽  
Retinal Photoreceptor ◽  
Morphometric Investigation ◽  
Hereditary Retinal Degeneration

scholarly journals Differential localizations of and requirements for the two Drosophila ninaC kinase/myosins in photoreceptor cells.

1992 ◽  
Vol 116 (3) ◽  
pp. 683-693 ◽  
Author(s):  
J A Porter ◽  
J L Hicks ◽  
D S Williams ◽  
C Montell
Keyword(s):  
Retinal Degeneration ◽  
Photoreceptor Cells ◽  
Kinase Domain ◽  
Electron Microscopic Level ◽  
Head Region ◽  
Electron Microscopic ◽  
Myosin I ◽  
Microvillar Structure ◽  
The Difference ◽  
The Individual

The ninaC gene encodes two retinal specific proteins (p132 and p174) consisting of a protein kinase domain joined to a domain homologous to the head region of the myosin heavy chain. The putative myosin domain of p174 is linked at the COOH-terminus to a tail which has some similarities to myosin-I tails. In the current report, we demonstrate that the ninaC mutation results in light- and age-dependent retinal degeneration. We also show that ninaC flies display an electrophysiological phenotype before any discernible retinal degeneration indicating that the electrophysiological defect is the primary effect of the mutation. This suggests that ninaC has a role in phototransduction and that the retinal degeneration is a secondary effect resulting from the defect in phototransduction. To examine the requirements for the individual ninaC isoforms, mutant alleles were generated which express only p132 or p174. Elimination of p174 resulted in a ninaC phenotype as strong as the null allele; however, elimination of p132 had little if any effect. As a first step in investigating the basis for the difference in requirements for p174 and p132 we performed immuno-localization at the electron microscopic level and found that the two isoforms display different subcellular distributions in the photoreceptor cells. The p132 protein is restricted primarily to the cytoplasm and p174 to the rhabdomeres, the microvillar structure which is the site of action of many of the steps in phototransduction. This suggests that the p174 myosin-I type tail is the domain responsible for association with the rhabdomeres and that the substrate for the p174 putative kinase may be a rhabdomeric protein important in photo-transduction.

scholarly journals Hereditary retinal degeneration in Drosophila melanogaster. A mutant defect associated with the phototransduction process.

1977 ◽  
Vol 69 (3) ◽  
pp. 261-291 ◽  
Author(s):  
W A Harris ◽  
W S Stark
Keyword(s):  
Acid Phosphatase ◽  
Retinal Degeneration ◽  
Receptor Potential ◽  
Photoreceptor Cells ◽  
Genetic Mosaics ◽  
Hereditary Retinal Degeneration ◽  
Kinetics Of ◽  
Prolonged Depolarizing Afterpotential

Two genes in Drosophila, rdgA and rdgB, which when defective cause retinal degeneration, were discovered by Hotta and Benzer (Hotta, Y., and S. Benzer. 1970. Proc. Natl, Acad. Sci. U. S, A. 67:1156-1163). These mutants have photoreceptor cells that are histologically normal upon eclosion but subsequently degenerate. The defects in the rdgA and rdgB mutants were localized by the study of genetic mosaics to the photoreceptor cells. In rdgB mutants retinal degeneration is light induced. It can be prevented by rearing the flies in the dark or by blocking the receptor potential with a no-receptor-potential mutation, norpA. Vitamin A deprivation and genetic elimination of the lysosomal enzyme acid phosphatase alsoprotect the photoreceptors of rdgB flies against light-induced damage. The photopigment kinetics of dark-reared rdgB flies appear normal in vitro by spectrophotometric measurements, and in vivo by measurements of the M potential. In normal Drosophila, a 1-s exposure to intense 470-nm light produces a prolonged depolarizing afterpotential (PDA) which can last for several hours. In dark-reared rdgB mutants the PDA lasts less than 2 min;; it appears to initiate the degeneration process, since the photoreceptors become permanently unresponsive after a single such exposure. Another mutant was isolated which prevents degeneration in rdgB flies but which has a normal receptor potential. This suppressor of degeneration is an allele of norpA. It is proposed that the normal norpA gene codes for a product which, when activated, leads to the receptor potential, and which is inactivated by the product of the normal rdgB gene.

scholarly journals Lysophosphatidylcholine acyltransferase 1 controls the mitochondrial reactive oxygen species generation and survival of the retinal photoreceptor cells

2021 ◽  
Author(s):  
Katsuyuki Nagata ◽  
Daisuke Hishikawa ◽  
Hiroshi Sagara ◽  
Masamichi Saito ◽  
Sumiko Watanabe ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Retinal Degeneration ◽  
Photoreceptor Cell ◽  
Reactive Oxygen ◽  
Photoreceptor Cells ◽  
Oxygen Species ◽  
Mitochondrial Reactive Oxygen Species ◽  
Retinal Photoreceptor

ABSTRACTDue to the high energy demands and characteristic morphology, retinal photoreceptor cells require a specialized lipid metabolism for survival and function. Accordingly, dysregulation of lipid metabolism leads to the photoreceptor cell death and retinal degeneration. Mice with a frameshift mutation of lysophosphatidylcholine acyltransferase 1 (Lpcat1), which produces saturated phosphatidylcholine (PC) composed of two saturated fatty acids, has been reported to cause spontaneous retinal degeneration (rd11 mice). In this study, we performed a detailed characterization of LPCAT1 in the retina and found that genetic deletion of Lpcat1 induces light-independent and photoreceptor-specific apoptosis in mice. Lipidomic analyses of the retina and isolated photoreceptor outer segment (OS) suggested that loss of Lpcat1 decreases saturated PC production and affects the proper cellular fatty acid flux, presumably by altering saturated fatty acyl-CoA availabilities. Furthermore, we demonstrated that Lpcat1 deletion increased mitochondrial reactive oxygen species (ROS) levels in photoreceptor cells, but not in other retinal cells without affecting the OS structure and trafficking of OS-localized proteins. These results suggest that the LPCAT1-dependent production of saturated PC is critical for metabolic adaptation during photoreceptor maturation. Our findings highlight the therapeutic potential of saturated fatty acid metabolism in photoreceptor cell degeneration-related retinal diseases.

Spindle shaped bodies in foveolar cones of the baboon retina

1989 ◽  
Vol 47 ◽  
pp. 960-961
Author(s):  
W. Krebs ◽  
I. Krebs
Keyword(s):  
Cross Sections ◽  
Inclusion Bodies ◽  
Photoreceptor Cells ◽  
Papio Anubis ◽  
Retinal Photoreceptor ◽  
Age Related ◽  
Cone Cells ◽  
Membrane Bound ◽  
Oriented Parallel ◽  
Shaped Inclusion

Various inclusion bodies occur in vertebrate retinal photoreceptor cells. Most of them are membrane bound and associated with phagocytosis or they are age related residual bodies. We found an additional inclusion body in foveal cone cells of the baboon (Papio anubis) retina.The eyes of a 15 year old baboon were fixed by immersion in cacodylate buffered glutaraldehyde (2%)/formaldehyde (2%) as described in detail elsewhere . Pieces of retina from various locations, including the fovea, were embedded in epoxy resin such that radial or tangential sections could be cut.Spindle shaped inclusion bodies were found in the cytoplasm of only foveal cones. They were abundant in the inner segments, close to the external limiting membrane (Fig. 1). But they also occurred in the outer fibers, the perikarya, and the inner fibers (Henle’s fibers) of the cone cells. The bodies were between 0.5 and 2 μm long. Their central diameter was 0.2 to 0. 3 μm. They always were oriented parallel to the long axis of the cone cells. In longitudinal sections (Figs. 2,3) they seemed to have a fibrous skeleton that, in cross sections, turned out to consist of plate-like (Fig.4) and tubular profiles (Fig. 5).

scholarly journals Nutraceutical Supplementation Ameliorates Visual Function, Retinal Degeneration, and Redox Status in rd10 Mice

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1033
Author(s):  
Lorena Olivares-González ◽  
Sheyla Velasco ◽  
Isabel Campillo ◽  
David Salom ◽  
Emilio González-García ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Retinal Degeneration ◽  
Antioxidant Properties ◽  
Photoreceptor Cells ◽  
Redox Status ◽  
Inherited Retinal Dystrophies ◽  
Stress Markers ◽  
Retinal Dystrophies ◽  
Progressive Degeneration ◽  
Light Stimuli

Background: Retinitis pigmentosa (RP) is a group of inherited retinal dystrophies characterized by progressive degeneration of photoreceptor cells. Ocular redox status is altered in RP suggesting oxidative stress could contribute to their progression. In this study, we investigated the effect of a mixture of nutraceuticals with antioxidant properties (NUT) on retinal degeneration in rd10 mice, a model of RP. Methods: NUT was orally administered to rd10 mice from postnatal day (PD) 9 to PD18. At PD18 retinal function and morphology were examined by electroretinography (ERG) and histology including TUNEL assay, immunolabeling of microglia, Müller cells, and poly ADP ribose polymers. Retinal redox status was determined by measuring the activity of antioxidant enzymes and some oxidative stress markers. Gene expression of the cytokines IL-6, TNFα, and IL-1β was assessed by real-time PCR. Results: NUT treatment delayed the loss of photoreceptors in rd10 mice partially preserving their electrical responses to light stimuli. Moreover, it ameliorated redox status and reduced inflammation including microglia activation, upregulation of cytokines, reactive gliosis, and PARP overactivation. Conclusions: NUT ameliorated retinal functionality and morphology at early stages of RP in rd10 mice. This formulation could be useful as a neuroprotective approach for patients with RP in the future.

scholarly journals Electroretinogram during Development of Hereditary Retinal Degeneration in the Dog

1955 ◽  
Vol 39 (6) ◽  
pp. 349-352 ◽  
Author(s):  
H. B. Parry ◽  
K. Tansley ◽  
L. C. Thomson
Keyword(s):  
Retinal Degeneration ◽  
Hereditary Retinal Degeneration

Retinal Oxygenation and Oxygen Metabolism in Abyssinian Cats with a Hereditary Retinal Degeneration

2006 ◽  
Vol 47 (8) ◽  
pp. 3683 ◽  
Author(s):  
Lissa Padnick-Silver ◽  
Jennifer J. Kang Derwent ◽  
Elizabeth Giuliano ◽  
Kristina Narfstro¨m ◽  
Robert A. Linsenmeier
Keyword(s):  
Retinal Degeneration ◽  
Oxygen Metabolism ◽  
Hereditary Retinal Degeneration
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