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Your search keyword '"Catherine Bowes Rickman"' showing total 2 results
Start Over Author "Catherine Bowes Rickman" Publisher public library of science (plos)
2 results on '"Catherine Bowes Rickman"'

1. Oxidative stress-mediated NFκB phosphorylation upregulates p62/SQSTM1 and promotes retinal pigmented epithelial cell survival through increased autophagy.

Author

Chunjuan Song, Sayak K Mitter, Xiaoping Qi, Eleni Beli, Haripriya V Rao, Jindong Ding, Colin S Ip, Hongmei Gu, Debra Akin, William A Dunn, Catherine Bowes Rickman, Alfred S Lewin, Maria B Grant, and Michael E Boulton

Subjects
Medicine, Science
Abstract

p62 is a scaffolding adaptor implicated in the clearance of protein aggregates by autophagy. Reactive oxygen species (ROS) can either stimulate or inhibit NFκB-mediated gene expression influencing cellular fate. We studied the effect of hydrogen peroxide (H2O2)-mediated oxidative stress and NFκB signaling on p62 expression in the retinal pigment epithelium (RPE) and investigated its role in regulation of autophagy and RPE survival against oxidative damage. Cultured human RPE cell line ARPE-19 and primary human adult and fetal RPE cells were exposed to H2O2-induced oxidative stress. The human apolipoprotein E4 targeted-replacement (APOE4) mouse model of AMD was used to study expression of p62 and other autophagy proteins in the retina. p62, NFκB p65 (total, phosphorylated, nuclear and cytoplasmic) and ATG10 expression was assessed by mRNA and protein analyses. Cellular ROS and mitochondrial superoxide were measured by CM-H2DCFDA and MitoSOX staining respectively. Mitochondrial viability was determined using MTT activity. qPCR-array system was used to investigate autophagic genes affected by p62. Nuclear and cytoplasmic levels of NFκB p65 were evaluated after cellular fractionation by Western blotting. We report that p62 is up-regulated in RPE cells under H2O2-induced oxidative stress and promotes autophagic activity. Depletion of endogenous p62 reduces autophagy by downregulation of ATG10 rendering RPE more susceptible to oxidative damage. NFκB p65 phosphorylation at Ser-536 was found to be critical for p62 upregulation in response to oxidative stress. Proteasome inhibition by H2O2 causes p62-NFκB signaling as antioxidant pre-treatment reversed p62 expression and p65 phosphorylation when RPE was challenged by H2O2 but not when by Lactacystin. p62 protein but not RNA levels are elevated in APOE4-HFC AMD mouse model, suggesting reduction of autophagic flux in disease conditions. Our findings suggest that p62 is necessary for RPE cytoprotection under oxidative stress and functions, in part, by modulating ATG10 expression. NFκB p65 activity may be a critical upstream initiator of p62 expression in RPE cells under oxidative stress.

Published
2017
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2. Oxidative stress-mediated NFκB phosphorylation upregulates p62/SQSTM1 and promotes retinal pigmented epithelial cell survival through increased autophagy

Author

Jindong Ding, Debra Akin, Catherine Bowes Rickman, Chunjuan Song, Eleni Beli, Sayak K. Mitter, Michael E. Boulton, William A. Dunn, Colin S. Ip, Maria B. Grant, Alfred S. Lewin, Hongmei Gu, Haripriya Vittal Rao, and Xiaoping Qi

Subjects
0301 basic medicine, lcsh:Medicine, Fluorescent Antibody Technique, Retinal Pigment Epithelium, Mitochondrion, medicine.disease_cause, Biochemistry, Macular Degeneration, Mice, chemistry.chemical_compound, Superoxides, Sequestosome-1 Protein, Small interfering RNAs, Post-Translational Modification, Phosphorylation, lcsh:Science, Energy-Producing Organelles, chemistry.chemical_classification, Multidisciplinary, Cell Death, NF-kappa B, RNA-Binding Proteins, Animal Models, Mitochondria, Up-Regulation, Cell biology, Nucleic acids, Experimental Organism Systems, Cell Processes, Cellular Structures and Organelles, Research Article, Cell Survival, Autophagic Cell Death, Blotting, Western, Lactacystin, Mouse Models, Bioenergetics, Research and Analysis Methods, Real-Time Polymerase Chain Reaction, Cell Line, 03 medical and health sciences, Model Organisms, Downregulation and upregulation, Genetics, Autophagy, medicine, Animals, Non-coding RNA, Reactive oxygen species, lcsh:R, Biology and Life Sciences, Proteins, Protein Complexes, Proteasomes, Cell Biology, NFKB1, Gene regulation, Oxidative Stress, Disease Models, Animal, 030104 developmental biology, chemistry, RNA, lcsh:Q, Gene expression, sense organs, Reactive Oxygen Species, Oxidative stress
Abstract

p62 is a scaffolding adaptor implicated in the clearance of protein aggregates by autophagy. Reactive oxygen species (ROS) can either stimulate or inhibit NFκB-mediated gene expression influencing cellular fate. We studied the effect of hydrogen peroxide (H2O2)-mediated oxidative stress and NFκB signaling on p62 expression in the retinal pigment epithelium (RPE) and investigated its role in regulation of autophagy and RPE survival against oxidative damage. Cultured human RPE cell line ARPE-19 and primary human adult and fetal RPE cells were exposed to H2O2-induced oxidative stress. The human apolipoprotein E4 targeted-replacement (APOE4) mouse model of AMD was used to study expression of p62 and other autophagy proteins in the retina. p62, NFκB p65 (total, phosphorylated, nuclear and cytoplasmic) and ATG10 expression was assessed by mRNA and protein analyses. Cellular ROS and mitochondrial superoxide were measured by CM-H2DCFDA and MitoSOX staining respectively. Mitochondrial viability was determined using MTT activity. qPCR-array system was used to investigate autophagic genes affected by p62. Nuclear and cytoplasmic levels of NFκB p65 were evaluated after cellular fractionation by Western blotting. We report that p62 is up-regulated in RPE cells under H2O2-induced oxidative stress and promotes autophagic activity. Depletion of endogenous p62 reduces autophagy by downregulation of ATG10 rendering RPE more susceptible to oxidative damage. NFκB p65 phosphorylation at Ser-536 was found to be critical for p62 upregulation in response to oxidative stress. Proteasome inhibition by H2O2 causes p62-NFκB signaling as antioxidant pre-treatment reversed p62 expression and p65 phosphorylation when RPE was challenged by H2O2 but not when by Lactacystin. p62 protein but not RNA levels are elevated in APOE4-HFC AMD mouse model, suggesting reduction of autophagic flux in disease conditions. Our findings suggest that p62 is necessary for RPE cytoprotection under oxidative stress and functions, in part, by modulating ATG10 expression. NFκB p65 activity may be a critical upstream initiator of p62 expression in RPE cells under oxidative stress.

Published
2017

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