scholarly journals Cell Culture Analysis of the Phagocytosis of Photoreceptor Outer Segments by Primary Mouse RPE Cells

2018 ◽  
pp. 63-71 ◽  
Author(s):  
Roni A. Hazim ◽  
David S. Williams
Keyword(s):  
Cell Culture ◽  
Rpe Cells ◽  
Photoreceptor Outer Segments ◽  
Outer Segments ◽  
Primary Mouse

scholarly journals THE CIRCADIAN CLOCK IN THE RETINAL PIGMENT EPITHELIUM CONTROLS THE DIURNAL RHYTHM OF PHAGOCYTIC ACTIVITY

2020 ◽  
Author(s):  
Christopher DeVera ◽  
Jendayi Dixon ◽  
Micah A. Chrenek ◽  
Kenkichi Baba ◽  
P. Michael Iuvone ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Circadian Clock ◽  
Phagocytic Activity ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Optomotor Response ◽  
Rpe Cells ◽  
Photoreceptor Outer Segments ◽  
Outer Segments ◽  
Old Mice

AbstractThe diurnal peak of phagocytosis by the retinal pigment epithelium (RPE) of photoreceptor outer segments (POS) is under circadian control, and it is believed that this process involves interactions from both the retina and RPE. Previous studies have demonstrated that a functional circadian clock exists within multiple retinal cell types and RPE cells. Thereby, the aim of the current study was to determine whether the circadian clock in the retina and or RPE controls the diurnal phagocytic peak of photoreceptor outer segments and whether selective disruption of the circadian clock in the RPE would affect RPE cells function and the viability during aging. To that aim, we first generated and validated an RPE tissue-specific KO of the essential clock gene, Bmal1, and then we determined the daily rhythm in phagocytic activity by the RPE in mice lacking a functional circadian clock in the retina or RPE. Then using electroretinography, spectral domain-optical coherence tomography, and optomotor response measurements of visual function we determined the effect of Bmal1 removal in young (6-month old) and old (18-month old) mice. RPE morphology and lipofuscin accumulation was also determined in young and old mice. Our data show that the circadian clock in the RPE controls the daily diurnal phagocytic peak of POS. Surprisingly, the lack of a functional RPE circadian clock or the diurnal phagocytic peak does not result in any detectable age-related degenerative phenotype in the retina or RPE. Thus, our results demonstrate that the loss of the circadian clock in the RPE or the lack of the daily peak in phagocytosis of POS does not result in deterioration of photoreceptors or the RPE during aging.

scholarly journals Toll-Like Receptor 4 (TLR4) of Retinal Pigment Epithelial Cells Participates in Transmembrane Signaling in Response to Photoreceptor Outer Segments

2004 ◽  
Vol 124 (2) ◽  
pp. 139-149 ◽  
Author(s):  
Andrei L. Kindzelskii ◽  
Victor M. Elner ◽  
Susan G. Elner ◽  
Dongli Yang ◽  
Bret A. Hughes ◽  
...  
Keyword(s):  
Retinal Pigment Epithelial ◽  
Retinal Pigment ◽  
Transmembrane Signaling ◽  
Calcium Signals ◽  
Rpe Cells ◽  
Photoreceptor Outer Segments ◽  
Pigment Epithelial ◽  
Outer Segments ◽  
Cell Interface ◽  
Human Rpe Cells

Retinal pigment epithelial (RPE) cells mediate the recognition and clearance of effete photoreceptor outer segments (POS), a process central to the maintenance of normal vision. Given the emerging importance of Toll-like receptors (TLRs) in transmembrane signaling in response to invading pathogens as well as endogenous substances, we hypothesized that TLRs are associated with RPE cell management of POS. TLR4 clusters on human RPE cells in response to human, but not bovine, POS. However, TLR4 clustering could be inhibited by saturating concentrations of an inhibitory anti-TLR4 mAb. Furthermore, human POS binding to human RPE cells elicited transmembrane metabolic and calcium signals within RPE cells, which could be blocked by saturating doses of an inhibitory anti-TLR4 mAb. However, the heterologous combination of bovine POS and human RPE did not trigger these signals. The pattern recognition receptor CD36 collected at the POS–RPE cell interface for both homologous and heterologous samples, but human TLR4 only collected at the human POS–human RPE cell interface. Kinetic experiments of human POS binding to human RPE cells revealed that CD36 arrives at the POS–RPE interface followed by TLR4 accumulation within 2 min. Metabolic and calcium signals immediately follow. Similarly, the production of reactive oxygen metabolites (ROMs) was observed for the homologous human system, but not the heterologous bovine POS–human RPE cell system. As (a) the bovine POS/human RPE combination did not elicit TLR4 accumulation, RPE signaling, or ROM release, (b) TLR4 arrives at the POS–RPE cell interface just before signaling, (c) TLR4 blockade with an inhibitory anti-TLR4 mAb inhibited TLR4 clustering, signaling, and ROM release in the human POS–human RPE system, and (d) TLR4 demonstrates similar clustering and signaling responses to POS in confluent RPE monolayers, we suggest that TLR4 of RPE cells participates in transmembrane signaling events that contribute to the management of human POS.

scholarly journals Annexin A2 Regulates Phagocytosis of Photoreceptor Outer Segments in the Mouse Retina

2009 ◽  
Vol 20 (17) ◽  
pp. 3896-3904 ◽  
Author(s):  
Ah-Lai Law ◽  
Qi Ling ◽  
Katherine A. Hajjar ◽  
Clare E. Futter ◽  
John Greenwood ◽  
...  
Keyword(s):  
Retinal Pigment ◽  
Polymerase Chain Reaction Analysis ◽  
Functional Differentiation ◽  
Mouse Retina ◽  
Rpe Cells ◽  
Photoreceptor Outer Segments ◽  
Pigment Epithelial ◽  
Outer Segments

The daily phagocytosis of shed photoreceptor outer segments by pigment epithelial cells is critical for the maintenance of the retina. In a subtractive polymerase chain reaction analysis, we found that functional differentiation of human ARPE19 retinal pigment epithelial (RPE) cells is accompanied by up-regulation of annexin (anx) A2, a major Src substrate and regulator of membrane–cytoskeleton dynamics. Here, we show that anx A2 is recruited to the nascent phagocytic cup in vitro and in vivo and that it fully dissociates once the phagosome is internalized. In ARPE19 cells depleted of anx A2 by using small interfering RNA and in ANX A2−/− mice the phagocytosis of outer segments was impaired, and in ANX A2−/− mice there was an accumulation of phagocytosed outer segments in the RPE apical processes, indicative of retarded phagosome transport. We show that anx A2 is tyrosine phosphorylated at the onset of phagocytosis and that the synchronized activation of focal adhesion kinase and c-Src is abnormal in ANX A2−/− mice. These findings reveal that anx A2 is involved in the circadian regulation of outer segment phagocytosis, and they provide new insight into the protein machinery that regulates phagocytic function in RPE cells.

Gas6 Binding to Photoreceptor Outer Segments Requires γ-Carboxyglutamic Acid (Gla) and Ca2+ and is Required for OS Phagocytosis by RPE Cells in vitro

2002 ◽  
Vol 75 (4) ◽  
pp. 391-400 ◽  
Author(s):  
Michael O. Hall ◽  
Martin S. Obin ◽  
Anne L. Prieto ◽  
Barry L. Burgess ◽  
Toshka A. Abrams
Keyword(s):  
Rpe Cells ◽  
Photoreceptor Outer Segments ◽  
Outer Segments ◽  
Carboxyglutamic Acid

Regeneration of Photoreceptor Outer Segments After Scleral Buckling Surgery for Rhegmatogenous Retinal Detachment

2017 ◽  
Vol 177 ◽  
pp. 17-26 ◽  
Author(s):  
Eimei Ra ◽  
Yasuki Ito ◽  
Kenichi Kawano ◽  
Takeshi Iwase ◽  
Hiroki Kaneko ◽  
...  
Keyword(s):  
Retinal Detachment ◽  
Rhegmatogenous Retinal Detachment ◽  
Scleral Buckling ◽  
Photoreceptor Outer Segments ◽  
Outer Segments

scholarly journals Human Photoreceptor Outer Segments Shorten During Light Adaptation

2013 ◽  
Vol 54 (5) ◽  
pp. 3721 ◽  
Author(s):  
Michael D. Abràmoff ◽  
Robert F. Mullins ◽  
Kyungmoo Lee ◽  
Jeremy M. Hoffmann ◽  
Milan Sonka ◽  
...  
Keyword(s):  
Light Adaptation ◽  
Photoreceptor Outer Segments ◽  
Outer Segments

scholarly journals Retrograde intraciliary trafficking of opsin during the maintenance of cone-shaped photoreceptor outer segments ofXenopus laevis

2014 ◽  
Vol 522 (16) ◽  
pp. 3577-3589 ◽  
Author(s):  
Guilian Tian ◽  
Kerrie H. Lodowski ◽  
Richard Lee ◽  
Yoshikazu Imanishi
Keyword(s):  
Photoreceptor Outer Segments ◽  
Outer Segments
Sign in / Sign up

Export Citation Format

Share Document