The Experts below are selected from a list of 90 Experts worldwide ranked by ideXlab platform
Robert S. Molday - One of the best experts on this subject based on the ideXlab platform.
-
retinoschisin rs1 the protein encoded by the x linked retinoschisis gene is anchored to the surface of Retinal photoreceptor and bipolar cells through its interactions with a na k atpase sarm1 complex
Journal of Biological Chemistry, 2007Co-Authors: Laurie L Molday, Winco W H Wu, Robert S. MoldayAbstract:Abstract Retinoschisin or RS1 is a discoidin domain-containing protein encoded by the gene responsible for X-linked retinoschisis (XLRS), an early onset macular degeneration characterized by a splitting of the Retina. Retinoschisin, expressed and secreted from photoreceptors and bipolar cells as a homo-octameric complex, associates with the surface of these cells where it serves to maintain the cellular organization of the Retina and the photoreceptor-bipolar synaptic structure. To gain insight into the role of retinoschisin in Retinal cell adhesion and the pathogenesis of XLRS, we have investigated membrane components in Retinal extracts that interact with retinoschisin. Unlike the discoidin domain-containing blood coagulation proteins Factor V and Factor VIII, retinoschisin did not bind to phospholipids or Retinal lipids reconstituted into unilamellar vesicles or immobilized on microtiter plates. Instead, co-immunoprecipitation studies together with mass spectrometric-based proteomics and Western blotting showed that retinoschisin is associated with a complex consisting of Na/K ATPase (α3, β2 isoforms) and the sterile alpha and TIR motif-containing protein SARM1. Double labeling studies for immunofluorescence microscopy confirmed the co-localization of retinoschisin with Na/K ATPase and SARM1 in photoreceptors and bipolar cells of Retina Tissue. We conclude that retinoschisin binds to Na/K ATPase on photoreceptor and bipolar cells. This interaction may be part of a novel SARM1-mediated cell signaling pathway required for the maintenance of Retinal cell organization and photoreceptor-bipolar synaptic structure.
-
retinoschisin rs1 the protein encoded by the x linked retinoschisis gene is anchored to the surface of Retinal photoreceptor and bipolar cells through its interactions with a na k atpase sarm1 complex
Journal of Biological Chemistry, 2007Co-Authors: Laurie L Molday, Robert S. MoldayAbstract:Retinoschisin or RS1 is a discoidin domain-containing protein encoded by the gene responsible for X-linked retinoschisis (XLRS), an early onset macular degeneration characterized by a splitting of the Retina. Retinoschisin, expressed and secreted from photoreceptors and bipolar cells as a homo-octameric complex, associates with the surface of these cells where it serves to maintain the cellular organization of the Retina and the photoreceptor-bipolar synaptic structure. To gain insight into the role of retinoschisin in Retinal cell adhesion and the pathogenesis of XLRS, we have investigated membrane components in Retinal extracts that interact with retinoschisin. Unlike the discoidin domain-containing blood coagulation proteins Factor V and Factor VIII, retinoschisin did not bind to phospholipids or Retinal lipids reconstituted into unilamellar vesicles or immobilized on microtiter plates. Instead, co-immunoprecipitation studies together with mass spectrometric-based proteomics and Western blotting showed that retinoschisin is associated with a complex consisting of Na/K ATPase (alpha3, beta2 isoforms) and the sterile alpha and TIR motif-containing protein SARM1. Double labeling studies for immunofluorescence microscopy confirmed the co-localization of retinoschisin with Na/K ATPase and SARM1 in photoreceptors and bipolar cells of Retina Tissue. We conclude that retinoschisin binds to Na/K ATPase on photoreceptor and bipolar cells. This interaction may be part of a novel SARM1-mediated cell signaling pathway required for the maintenance of Retinal cell organization and photoreceptor-bipolar synaptic structure.
Laurie L Molday - One of the best experts on this subject based on the ideXlab platform.
-
retinoschisin rs1 the protein encoded by the x linked retinoschisis gene is anchored to the surface of Retinal photoreceptor and bipolar cells through its interactions with a na k atpase sarm1 complex
Journal of Biological Chemistry, 2007Co-Authors: Laurie L Molday, Winco W H Wu, Robert S. MoldayAbstract:Abstract Retinoschisin or RS1 is a discoidin domain-containing protein encoded by the gene responsible for X-linked retinoschisis (XLRS), an early onset macular degeneration characterized by a splitting of the Retina. Retinoschisin, expressed and secreted from photoreceptors and bipolar cells as a homo-octameric complex, associates with the surface of these cells where it serves to maintain the cellular organization of the Retina and the photoreceptor-bipolar synaptic structure. To gain insight into the role of retinoschisin in Retinal cell adhesion and the pathogenesis of XLRS, we have investigated membrane components in Retinal extracts that interact with retinoschisin. Unlike the discoidin domain-containing blood coagulation proteins Factor V and Factor VIII, retinoschisin did not bind to phospholipids or Retinal lipids reconstituted into unilamellar vesicles or immobilized on microtiter plates. Instead, co-immunoprecipitation studies together with mass spectrometric-based proteomics and Western blotting showed that retinoschisin is associated with a complex consisting of Na/K ATPase (α3, β2 isoforms) and the sterile alpha and TIR motif-containing protein SARM1. Double labeling studies for immunofluorescence microscopy confirmed the co-localization of retinoschisin with Na/K ATPase and SARM1 in photoreceptors and bipolar cells of Retina Tissue. We conclude that retinoschisin binds to Na/K ATPase on photoreceptor and bipolar cells. This interaction may be part of a novel SARM1-mediated cell signaling pathway required for the maintenance of Retinal cell organization and photoreceptor-bipolar synaptic structure.
-
retinoschisin rs1 the protein encoded by the x linked retinoschisis gene is anchored to the surface of Retinal photoreceptor and bipolar cells through its interactions with a na k atpase sarm1 complex
Journal of Biological Chemistry, 2007Co-Authors: Laurie L Molday, Robert S. MoldayAbstract:Retinoschisin or RS1 is a discoidin domain-containing protein encoded by the gene responsible for X-linked retinoschisis (XLRS), an early onset macular degeneration characterized by a splitting of the Retina. Retinoschisin, expressed and secreted from photoreceptors and bipolar cells as a homo-octameric complex, associates with the surface of these cells where it serves to maintain the cellular organization of the Retina and the photoreceptor-bipolar synaptic structure. To gain insight into the role of retinoschisin in Retinal cell adhesion and the pathogenesis of XLRS, we have investigated membrane components in Retinal extracts that interact with retinoschisin. Unlike the discoidin domain-containing blood coagulation proteins Factor V and Factor VIII, retinoschisin did not bind to phospholipids or Retinal lipids reconstituted into unilamellar vesicles or immobilized on microtiter plates. Instead, co-immunoprecipitation studies together with mass spectrometric-based proteomics and Western blotting showed that retinoschisin is associated with a complex consisting of Na/K ATPase (alpha3, beta2 isoforms) and the sterile alpha and TIR motif-containing protein SARM1. Double labeling studies for immunofluorescence microscopy confirmed the co-localization of retinoschisin with Na/K ATPase and SARM1 in photoreceptors and bipolar cells of Retina Tissue. We conclude that retinoschisin binds to Na/K ATPase on photoreceptor and bipolar cells. This interaction may be part of a novel SARM1-mediated cell signaling pathway required for the maintenance of Retinal cell organization and photoreceptor-bipolar synaptic structure.
Lily Vardimon - One of the best experts on this subject based on the ideXlab platform.
-
basic fibroblast growth factor a potential inhibitor of glutamine synthetase expression in injured neural Tissue
Journal of Neurochemistry, 2001Co-Authors: Yelena Kruchkova, Iris Bendror, Avia Herschkovitz, Magda David, Avner Yayon, Lily VardimonAbstract:Basic fibroblast growth factor (bFGF) was recently shown to promote the survival of neural cells and Tissues, raising hopes for its therapeutic potential in degenerative disorders of the CNS. Here we examine the effect of bFGF on the expression of glutamine synthetase, a key enzyme in the detoxification of the neurotransmitter glutamate. Expression of this enzyme is regulated by systemic glucocorticoids and, in chick neural Retina Tissue, is restricted to Muller glial cells. We report that exogenous supply of bFGF to Retinal explants inhibits hormonal induction of glutamine synthetase expression. This inhibition appears to be mediated by the c-Jun protein which accumulated, in response to bFGF, exclusively in Muller glial cells. Ischemic conditions, which reportedly stimulate the release of endogenous bFGF, also led to an increase in c-Jun protein and a decline in glutamine synthetase expression. This decline could be competitively prevented by a soluble fibroblast growth factor receptor but not by a soluble epidermal growth factor receptor. The finding that endogenous release of bFGF or its exogenous supply down-regulates glutamine synthetase expression suggests that in addition to its reported neuroprotective effect, bFGF may exacerbate glutamate mediated neurotoxicity through direct down-regulation of glutamine synthetase.
-
Molecular control of glutamine synthetase expression in the developing Retina Tissue.
Developmental Dynamics, 1993Co-Authors: Lily Vardimon, Iris Ben-dror, Nadav Havazelet, Lyle E. FoxAbstract:Glutamine synthetase is a differentiation marker of the neural Retina, whose expression is restricted to Muller glia cells, is inducible by glucocorticoids and is dependent on Tissue development. The Retina Tissue acquires the competence to express GS in response to glucocorticoids with development, although the level of hormone binding activity in the cells does not alter with age. Using CAT constructs that are controlled by “simple GRE” promoters we demonstrated that glucocorticoid receptor transcription activity in Retina cells increases with development. The increase in receptor activity correlates directly with the increase in inducibility of the glutamine synthetase gene and inversely with the rate of Retina cell proliferation. At early developmental ages, when Retina cells are still proliferating, the glucocorticoid receptor is transcriptionally inactive and glutamine synthetase expression cannot be induced. Receptor activity increases progressively with development and by day 12, when cell proliferation ceases, competence for glutamine synthetase induction is high. This competence for glutamine synthetase induction can be repressed by overexpressing the oncogene v-src, which stimulates Retina cell proliferation. We discuss possible mechanisms for developmental-dependent modulation of glucocorticoid receptor transcriptional activity. © 1993 wiley-Liss, Inc.
Ga Mcconkey - One of the best experts on this subject based on the ideXlab platform.
-
Experimental Toxoplasmosis in Rats Induced Orally with Eleven Strains of Toxoplasma gondii of Seven Genotypes: Tissue Tropism, Tissue Cyst Size, Neural Lesions, Tissue Cyst Rupture without Reactivation, and Ocular Lesions.
'Public Library of Science (PLoS)', 2016Co-Authors: Jp Dubey, Lr Ferreira, Alsaad M, Sk Verma, Da Alves, Gn Holland, Ga McconkeyAbstract:The protozoan parasite Toxoplasma gondii is one of the most widely distributed and successful parasites. Toxoplasma gondii alters rodent behavior such that infected rodents reverse their fear of cat odor, and indeed are attracted rather than repelled by feline urine. The location of the parasite encysted in the brain may influence this behavior. However, most studies are based on the highly susceptible rodent, the mouse.Latent toxoplasmosis was induced in rats (10 rats per T. gondii strains) of the same age, strain, and sex, after oral inoculation with oocysts (natural route and natural stage of infection) of 11 T. gondii strains of seven genotypes. Rats were euthanized at two months post inoculation (p.i.) to investigate whether the parasite genotype affects the distribution, location, Tissue cyst size, or lesions. Tissue cysts were enumerated in different regions of the brains, both in histological sections as well in saline homogenates. Tissue cysts were found in all regions of the brain. The Tissue cyst density in different brain regions varied extensively between rats with many regions highly infected in some animals. Overall, the colliculus was most highly infected although there was a large amount of variability. The cerebral cortex, thalamus, and cerebellum had higher Tissue cyst densities and two strains exhibited tropism for the colliculus and olfactory bulb. Histologically, lesions were confined to the brain and eyes. Tissue cyst rupture was frequent with no clear evidence for reactivation of tachyzoites. Ocular lesions were found in 23 (25%) of 92 rat eyes at two months p.i. The predominant lesion was focal inflammation in the Retina. Tissue cysts were seen in the sclera of one and in the optic nerve of two rats. The choroid was not affected. Only Tissue cysts, not active tachyzoite infections, were detected. Tissue cysts were seen in histological sections of tongue of 20 rats but not in myocardium and leg muscle.This study reevaluated in depth the rat model of toxoplasmosis visualizing cyst rupture and clarified many aspects of the biology of the parasite useful for future investigations
Glenn A. Mcconkey - One of the best experts on this subject based on the ideXlab platform.
-
Experimental Toxoplasmosis in Rats Induced Orally with Eleven Strains of Toxoplasma gondii of Seven Genotypes: Tissue Tropism, Tissue Cyst Size, Neural Lesions, Tissue Cyst Rupture without Reactivation, and Ocular Lesions
2016Co-Authors: Jitender P. Dubey, Leandra R. Ferreira, Mohammad Alsaad, Shiv K. Verma, Derron A. Alves, Gary N. Holland, Glenn A. McconkeyAbstract:BackgroundThe protozoan parasite Toxoplasma gondii is one of the most widely distributed and successful parasites. Toxoplasma gondii alters rodent behavior such that infected rodents reverse their fear of cat odor, and indeed are attracted rather than repelled by feline urine. The location of the parasite encysted in the brain may influence this behavior. However, most studies are based on the highly susceptible rodent, the mouse.Methodology/Principal FindingsLatent toxoplasmosis was induced in rats (10 rats per T. gondii strains) of the same age, strain, and sex, after oral inoculation with oocysts (natural route and natural stage of infection) of 11 T. gondii strains of seven genotypes. Rats were euthanized at two months post inoculation (p.i.) to investigate whether the parasite genotype affects the distribution, location, Tissue cyst size, or lesions. Tissue cysts were enumerated in different regions of the brains, both in histological sections as well in saline homogenates. Tissue cysts were found in all regions of the brain. The Tissue cyst density in different brain regions varied extensively between rats with many regions highly infected in some animals. Overall, the colliculus was most highly infected although there was a large amount of variability. The cerebral cortex, thalamus, and cerebellum had higher Tissue cyst densities and two strains exhibited tropism for the colliculus and olfactory bulb. Histologically, lesions were confined to the brain and eyes. Tissue cyst rupture was frequent with no clear evidence for reactivation of tachyzoites. Ocular lesions were found in 23 (25%) of 92 rat eyes at two months p.i. The predominant lesion was focal inflammation in the Retina. Tissue cysts were seen in the sclera of one and in the optic nerve of two rats. The choroid was not affected. Only Tissue cysts, not active tachyzoite infections, were detected. Tissue cysts were seen in histological sections of tongue of 20 rats but not in myocardium and leg muscle.Conclusion/SignificanceThis study reevaluated in depth the rat model of toxoplasmosis visualizing cyst rupture and clarified many aspects of the biology of the parasite useful for future investigations.