scholarly journals A photoreceptor calcium binding protein is recognized by autoantibodies obtained from patients with cancer-associated retinopathy.

1991 ◽  
Vol 112 (5) ◽  
pp. 981-989 ◽  
Author(s):  
A S Polans ◽  
J Buczyłko ◽  
J Crabb ◽  
K Palczewski
Keyword(s):  
Calcium Binding ◽  
Photoreceptor Cells ◽  
Specific Protein ◽  
Exchange Chromatography ◽  
Rod Photoreceptor ◽  
Outer Segments ◽  
Binding Domains ◽  
Retinal Photoreceptors ◽  
Diagnosis Of Cancer ◽  
Cancer Associated Retinopathy

Cancer-associated retinopathy (CAR), a paraneoplastic syndrome, is characterized by the degeneration of retinal photoreceptors under conditions where the tumor and its metastases have not invaded the eye. The retinopathy often is apparent before the diagnosis of cancer and may be associated with autoantibodies that react with specific sites in the retina. We have examined the sera from patients with CAR to further characterize the retinal antigen. Western blot analysis of human retinal proteins reveals a prominent band at 26 kD that is labeled by the CAR antisera. Antibodies to the 26-kD protein were affinity-purified from complex CAR antisera and used for EM-immunocytochemical localization of the protein to the nuclei, inner and outer segments of both rod and cone cells. Other antibodies obtained from the CAR sera did not label photoreceptors. Using the affinity-purified antibodies for detection, the 26-kD protein, designated p26, was purified to homogeneity from the outer segments of bovine rod photoreceptor cells by Phenyl-Sepharose and ion exchange chromatography. Partial amino acid sequence of p26 was determined by gas phase Edman degradation and revealed extensive homology with a cone-specific protein, visinin. Based upon structural relatedness, both the p26 rod protein and visinin are members of the calmodulin family and contain calcium binding domains of the E-F hand structure.

scholarly journals Visualization of intracellular concanavalin A binding sites in retinal photoreceptors.

1978 ◽  
Vol 26 (10) ◽  
pp. 822-828 ◽  
Author(s):  
I Nir
Keyword(s):  
Concanavalin A ◽  
Binding Sites ◽  
Photoreceptor Cells ◽  
Con A ◽  
Thin Sections ◽  
Glycol Methacrylate ◽  
Outer Segments ◽  
Retinal Photoreceptors ◽  
Carbohydrate Components ◽  
The Relationship

Localization of carbohydrate components in retinal photoreceptor cells and membranes was studied. Frog and rat retinas were fixed with glutaraldehyde and embedded in glycol methacrylate or in a mixture of glycol methacrylate, glutaraldehyde and urea. Thin sections were incubated with ferritin-labeled concanavalin A (F-Con A) and stained with osmium vapors. Intensive binding was observed in both rod and cone outer segments. In the rod inner segment, differential binding of F-Con A was demonstrated. While numerous ferritin granules were observed in the myoid zone, only a few were seen in the ellipsoid zone, except for a local accumulation along the plasma membrane. In the rod outer segment, Con A binding sites were closely associated with the disk membranes. Ferritin granules were observed on both sides of the membranes. The relationship between the localization of Con A binding sites and the orientation of visual pigment molecules within the rod outer segments disk membranes was discussed.

scholarly journals Immunocytochemical localization of opsin in the cell membrane of developing rat retinal photoreceptors.

1984 ◽  
Vol 98 (5) ◽  
pp. 1788-1795 ◽  
Author(s):  
I Nir ◽  
D Cohen ◽  
D S Papermaster
Keyword(s):  
Plasma Membrane ◽  
Outer Segment ◽  
Plasma Membranes ◽  
Photoreceptor Cells ◽  
Rod Photoreceptor ◽  
Rod Photoreceptors ◽  
Retinal Photoreceptors ◽  
Retinal Rod ◽  
Ros Formation ◽  
Developing Rat

Mature retinal rod photoreceptors sequester opsin in the disk and plasma membranes of the rod outer segment (ROS). Opsin is synthesized in the inner segment and is transferred to the outer segment along the connecting cilium that joins the two compartments. We have investigated early stages of retinal development during which the polarized distribution of opsin is established in the rod photoreceptor cell. Retinas were isolated from newborn rats, 3-21 d old, and incubated with affinity purified biotinyl-sheep anti-bovine opsin followed by avidin-ferritin. At early postnatal ages prior to the development of the ROS, opsin is labeled by antiopsin on the inner segment plasma membrane. At the fifth postnatal day, as ROS formation begins opsin was detected on the connecting cilium plasma membrane. However, the labeling density of the ciliary plasma membrane was not uniform: the proximal cilium was relatively unlabeled in comparison with the distal cilium and the ROS plasma membrane. In nearly mature rat retinas, opsin was no longer detected on the inner segment plasma membrane. A similar polarized distribution of opsin was also observed in adult human rod photoreceptor cells labeled with the same antibodies. These results suggest that some component(s) of the connecting cilium and its plasma membrane may participate in establishing and maintaining the polarized distribution of opsin.

scholarly journals Localization of peripherin/rds in the disk membranes of cone and rod photoreceptors: relationship to disk membrane morphogenesis and retinal degeneration.

1992 ◽  
Vol 116 (3) ◽  
pp. 659-667 ◽  
Author(s):  
K Arikawa ◽  
L L Molday ◽  
R S Molday ◽  
D S Williams
Keyword(s):  
Plasma Membrane ◽  
Retinal Degeneration ◽  
Outer Segment ◽  
Photoreceptor Cells ◽  
Growth Stages ◽  
Rod Outer Segments ◽  
Rod Photoreceptor ◽  
Outer Segments ◽  
Disk Membrane ◽  
Membrane Morphogenesis

The outer segments of vertebrate rod photoreceptor cells consist of an ordered stack of membrane disks, which, except for a few nascent disks at the base of the outer segment, is surrounded by a separate plasma membrane. Previous studies indicate that the protein, peripherin or peripherin/rds, is localized along the rim of mature disks of rod outer segments. A mutation in the gene for this protein has been reported to be responsible for retinal degeneration in the rds mouse. In the present study, we have shown by immunogold labeling of rat and ground squirrel retinas that peripherin/rds is present in the disk rims of cone outer segments as well as rod outer segments. Additionally, in the basal regions of rod and cone outer segments, where disk morphogenesis occurs, we have found that the distribution of peripherin/rds is restricted to a region that is adjacent to the cilium. Extension of its distribution from the cilium coincides with the formation of the disk rim. These results support the model of disk membrane morphogenesis that predicts rim formation to be a second stage of growth, after the first stage in which the ciliary plasma membrane evaginates to form open nascent disks. The results also indicate how the proteins of the outer segment plasma membrane and the disk membranes are sorted into their separate domains: different sets of proteins may be incorporated into membrane outgrowths during different growth stages of disk morphogenesis. Finally, the presence of peripherin/rds protein in both cone and rod outer segment disks, together with the phenotype of the rds mouse, which is characterized by the failure of both rod and cone outer segment formation, suggest that the same rds gene is expressed in both types of photoreceptor cells.

scholarly journals FINE STRUCTURE OF THE PINEAL ORGANS OF THE ADULT FROG, RANA PIPIENS

1964 ◽  
Vol 22 (3) ◽  
pp. 653-674 ◽  
Author(s):  
Douglas E. Kelly ◽  
Stuart W. Smith
Keyword(s):  
Rana Pipiens ◽  
Photoreceptor Cells ◽  
Rods And Cones ◽  
Adult Frog ◽  
Outer Segments ◽  
Lateral Eye ◽  
Retinal Photoreceptors ◽  
Retinal Rods ◽  
Cytological Features ◽  
Pineal Photoreceptors

Frontal organs and epiphyses of the pineal system from the adult frog, Rana pipiens, were fixed in s-collidine-buffered osmium tetroxide, embedded in Epon 812, and examined by electron microscopy. Epiphyseal material was also fixed in a variety of ways and subjected to a series of cytochemical tests for light microscopy. An ultrastructure resembling that of lateral eye retina is confirmed in this species. Photoreceptor cells of the epiphysis and frontal organ display many cytological features similar to those of retinal rods and cones in the arrangement of their outer and inner segments and synaptic components. However, in these pineal organs the outer segments are disoriented relative to each other and may display a disarranged internal organization unlike normal retinal photoreceptors. Furthermore, other pineal outer segments often appear degenerate. Since immature stages in the development of new outer segments also appear to be present, adult pineal photoreceptors are probably engaged in a constant renewal of outer segment membranes. The evidence further suggests that macrophages are involved in phagocytosis of degenerated outer segments. Postulated photoreceptor activities and the possibility of secondary pineal functions, such as secretion, are discussed in view of current morphological and cytochemical findings.

Calbindin D-28K immunoreactivity of human cone cells varies with retinal position

1995 ◽  
Vol 12 (2) ◽  
pp. 301-307 ◽  
Author(s):  
Tammie L. Haley ◽  
Roland Pochet ◽  
Larry Baizer ◽  
Miriam D. Burton ◽  
John W. Crabb ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Photoreceptor Cells ◽  
Rod Photoreceptor ◽  
Amino Acid Sequence Analysis ◽  
Retinal Position ◽  
Partial Amino Acid Sequence ◽  
Retinal Tissue ◽  
Cone Cells ◽  
The One ◽  
Calbindin D

AbstractCalbindin D-28K is a calcium-binding protein found in the cone but not rod photoreceptor cells in the retinas of a variety of species. Recent studies of the monkey retina indicated that calbindin D-28K may be expressed preferentially in non-foveal regions of the retina. In the current studies of human retinas, immunohistochemical experiments demonstrated that calbindin D-28K is reduced or absent in the fovea and parafovea, but prevalent in the perifovea and periphery. These findings were supported by the quantification of calbindin D-28K in 1-mm trephine punches obtained from different regions of the human retina. The specificity of the anti-calbindin D-28K antibodies used in these studies was confirmed by Western blot analysis using purified calbindin D-28K. The protein was purified from retinal tissue and its identity confirmed by partial amino-acid sequence analysis. The expression of calbindin D-28K did not correlate with the spectral properties of the cones, rather to their position in the retina. The study of spatially expressed genes, like the one encoding calbindin D-28K, may help explain the patterns of retinal degeneration seen in some human cone-rod dystrophies.

Ayurvedic management of Retinitis Pigmentosa (Doshandha) - A Case Study

2017 ◽  
Vol 2 (05) ◽  
Author(s):  
Anju D. ◽  
Pushpa Raj Poudel ◽  
Ajoy Viswam ◽  
Ashwini M. J.
Keyword(s):  
Retinitis Pigmentosa ◽  
Low Vision ◽  
Symptomatic Relief ◽  
Retinal Dystrophy ◽  
Treatment Protocol ◽  
Signs And Symptoms ◽  
Photoreceptor Cells ◽  
Rod Photoreceptor ◽  
Night Time ◽  
Initial Symptoms

Retinitis pigmentosa (RP) is an inherited, degenerative eye disease that causes severe vision impairment due to the progressive degeneration of rod photoreceptor cells in retina. This form of retinal dystrophy manifests initial symptoms independentof age; thus, RP diagnosis occurs anywhere from early infancy to late adulthood. This primary pigmentary retinal dystrophy is a hereditary disorder predominantly affecting the rods more than the cones. The main classical triads of retinitis pigmentosa are arteriolar attenuation, Retinal bone spicule pigmentation and Waxy disc pallor. The main treatment of retinitis pigmentosa is by using Low vision aids (LVA) and Genetic counseling. As such a complete cure for retinitis pigmentosa is not present. So a treatment protocol has to be adopted that helps in at least the symptomatic relief. In Ayurveda, the signs and symptoms of this can be compared with the Lakshanas of Doshandha which is one among the Dristigata Roga. It is considered as a diseased condition in which sunset will obliterate the Dristi Mandala and makes the person blind at night time. During morning hours the rising sunrays will disperse the accumulated Dosas from Dristi to clear vision. This disease resembles Kaphajatimira in its pathogenesis, but the night blindness is the special feature. Since the disease is purely Kaphaja, a treatment attempt is planned in Kaphara and Brimhana line. The present paper discusses a case of retinitis pigmentosa and it’s Ayurvedic Treatment.

scholarly journals Mutations in calphotin, the gene encoding a Drosophila photoreceptor cell-specific calcium-binding protein, reveal roles in cellular morphogenesis and survival.

Genetics ◽  
1994 ◽  
Vol 138 (2) ◽  
pp. 413-421 ◽  
Author(s):  
Y Yang ◽  
D Ballinger
Keyword(s):  
Calcium Binding ◽  
Photoreceptor Cell ◽  
Cell Structure ◽  
Specific Protein ◽  
Cell Organelle ◽  
Cell Type ◽  
Gene Encoding ◽  
Cellular Morphogenesis ◽  
Transgenic Flies ◽  
Drosophila Photoreceptor

Abstract Calphotin is a Drosophila photoreceptor cell-specific protein expressed very early in eye development, at the time when cell-type decisions are being made. Calphotin is a very hydrophobic and proline-rich protein which lacks obvious transmembrane domains. The cDNA encoding Calphotin was mapped to a region removed by a set of existing chromosomal deletions. Mutations that alter photoreceptor cell structure and development were isolated that fail to complement these deletions. These mutations fall into two classes. Class I mutations alter the structure of the rhabdomere, a photoreceptor cell organelle specialized for phototransduction. Class II mutations have rough eyes, due to misorientation of the rhabdomeres and photoreceptor cell death. Transformation rescue of these phenotypes in transgenic flies bearing calphotin genomic DNA indicates that both classes of mutations are in the calphotin gene. Analysis of these mutations suggest that Calphotin plays important roles in both rhabdomere development and in photoreceptor cell survival.

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