Outer segment disc membrane assembly in the absence of the pigment epithelium: the effect of exogenous sugars

Stiemke, Monica M.; Hollyfield, Joe G.

doi:10.1016/0165-3806(94)90115-5

Cited by 21 publications

(15 citation statements)

References 13 publications

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“…The structure of the ROS can be disrupted with the removal of the RPE. In a cell culture system the normal ROS structure (organized stacked flattened membrane disks) can, however, be maintained in a culture system supplemented with permissive sugars: galactose and lactose (Stiemke and Hollyfield, 1994). Early studies in which retinas were treated with tunicamycin Ulshafer et al, 1986), an inhibitor of N-linked glycosylation, documented newly synthesized membrane material to form whorl-like or tubulovesicular structures rather than normal ROS disks (Mercurio and Holtzman, 1982).…”

Section: A Disk Morphogenesismentioning

confidence: 99%

Photoreceptor renewal: A role for peripherin/rds

Boesze‐Battaglia¹,

Goldberg²

2002

International Review of Cytology

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Visual transduction begins with the detection of light within the photoreceptor cell layer of the retina. Within this layer, specialized cells, termed rods and cones, contain the proteins responsible for light capture and its transduction to nerve impulses. The phototransductive proteins reside within an outer segment region that is connected to an inner segment by a thin stalk rich in cytoskeletal elements. A unique property of the outer segments is the presence of an elaborate intracellular membrane system that holds the phototransduction proteins and provides the requisite lipid environment. The maintenance of normal physiological function requires that these postmitotic cells retain the unique structure of the outer segment regions-stacks of membrane saccules in the case of rods and a continuous infolding of membrane in the case of cones. Both photoreceptor rod and cone cells achieve this through a series of coordinated steps. As new membranous material is synthesized, transported, and incorporated into newly forming outer segment membranes, a compensatory shedding of older membranous material occurs, thereby maintaining the segment at a constant length. These processes are collectively referred to as ROS (rod outer segment) or COS (cone outer segment) renewal. We review the cellular and molecular events responsible for these renewal processes and present the recent but compelling evidence, drawn from molecular genetic, biochemical, and biophysical approaches, pointing to an essential role for a unique tetraspanning membrane protein, called peripherin/rds, in the processes of disk morphogenesis.

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Section: A Disk Morphogenesismentioning

confidence: 99%

Photoreceptor renewal: A role for peripherin/rds

Boesze‐Battaglia¹,

Goldberg²

2002

International Review of Cytology

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“…In all other vertebrate models, photoreceptors elaborate very few rudimentary outer segment membranous leaflets when separated from the RPE (Adler 1986; Adler 1987; Adler and Politi 1989; Araki et al 1987; Caffé et al 1989; Lahav 1987; LaVail and Hild 1971; Politi et al 1988; Roof et al 1991; Saga et al 1996; Sehgal et al 2006; Watanabe and Raff 1990). An additional feature of the Xenopus intact eye model is that in the RPE-deprived state, the membranes are disorganized (Jablonski and Ervin 2000; Jablonski et al 1999; Stiemke and Hollyfield 1994; Stiemke et al 1994), but abundant enough to make it possible to determine which proteins may be critical for assembly of outer segments. Moreover, eyes remain intact with no dissociation into single cells, therefore photoreceptors maintain their association with Müller radial glial cells and neighboring neurons.…”

Section: Discussionmentioning

confidence: 99%

“…Thus the influence of the RPE upon photoreceptor development is greatly minimized, yet the cell population remains present and it is therefore not necessary to subtract the RPE proteome from that of the RPE-supported condition to equalize the proteomes of the experimental conditions. In addition, because phagocytosis of outer segments by the RPE is not initiated until several stages after the harvesting of eyes (Stiemke and Hollyfield 1994), any potential proteome differences due to the absence of outer segment engulfment by the RPE are non-existent.…”

Section: Methodsmentioning

confidence: 99%

“…In our previous studies on the Xenopus laevis tadpole retina, we have demonstrated that removal of the RPE not only disrupts outer segment assembly, but also alters the protein expression profiles of both photoreceptors and Müller cells (Jablonski and Iannaccone 2001; Jablonski et al 1999; Stiemke and Hollyfield 1994). It is presently unknown if the ability of the RPE to support outer segment assembly is direct upon photoreceptors themselves, or are indirect via Müller cells and/other retinal neurons.…”

Section: Introductionmentioning

confidence: 98%

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Proteomic analysis of the retina: Removal of RPE alters outer segment assembly and retinal protein expression

Wang¹,

Nookala²,

Narayanan³

et al. 2008

Glia

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The mechanisms that regulate the complex physiologic task of photoreceptor outer segment assembly remain an enigma. One limiting factor in revealing the mechanism(s) by which this process is modulated is that not all of the role players that participate in this process are known. The purpose of this study was to determine some of the retinal proteins that likely play a critical role in regulating photoreceptor outer segment assembly. To do so, we analyzed and compared the proteome map of tadpole Xenopus laevis retinal pigment epithelium (RPE)-supported retinas containing organized outer segments with that of RPE-deprived retinas containing disorganized outer segments. Solubilized proteins were labeled with CyDye fluors followed by multiplexed two-dimensional separation. The intensity of protein spots and comparison of proteome maps was performed using DeCyder software. Identification of differentially regulated proteins was determined using nanoLC-ESI-MS/MS analysis. We found a total of 27 protein spots, 21 of which were unique proteins, which were differentially expressed in retinas with disorganized outer segments. We predict that in the absence of the RPE, oxidative stress initiates an unfolded protein response. Subsequently, downregulation of several candidate Müller glial cell proteins may explain the inability of photoreceptors to properly fold their outer segment membranes. In this study we have used identification and bioinformatics assessment of proteins that are differentially expressed in retinas with disorganized outer segments as a first step in determining probable key molecules involved in regulating photoreceptor outer segment assembly.

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“…Subsequently, GDNF has been found to be expressed in numerous areas including the retina and to have effects upon peripheral sensory and motor neurons (Trupp et al, 1995 ;Norsat et al, 1996). N-acetyl -galactosamine (NAD-gal) is one of several sugars that has been shown to be permissive of outer segment formation in vitro in the absence of an RPE cell layer in Xenopus (Stiemke and Hollyfield, 1994). Pigment epithelial cell derived factor (PEDF) is a retinal factor that increases viability of cerebeller granule cells in vitro (Taniwaki et al, 1995(Taniwaki et al, , 1997.…”

Section: Introductionmentioning

confidence: 99%