Inhibition of phagocytic activity of ARPE-19 cells by free radical mediated oxidative stress

Olchawa, Magdalena; Piłat, Anna; Szewczyk, Grzegorz; Sarna, Tadeusz

doi:10.1080/10715762.2016.1194519

Cited by 17 publications

(16 citation statements)

References 55 publications

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“…This results in a vicious circle ultimately leading to apoptosis. The sustained high concentration of intracellular Ca 2+ , followed by activation of calpains, which critically mediates the subsequent ER-mitochondrial cross-talk [ 49 , 50 , 51 , 52 , 53 ]. Recent studies have shown that Ca 2+ is associated with the formation of the autophagosome [ 54 , 55 ].…”

Section: Discussionmentioning

confidence: 99%

Inhibition of Starvation-Triggered Endoplasmic Reticulum Stress, Autophagy, and Apoptosis in ARPE-19 Cells by Taurine through Modulating the Expression of Calpain-1 and Calpain-2

Zhang

Ren

Liu

et al. 2017

IJMS

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Age-related macular degeneration (AMD) is a complex disease with multiple initiators and pathways that converge on death for retinal pigment epithelial (RPE) cells. In this study, effects of taurine on calpains, autophagy, endoplasmic reticulum (ER) stress, and apoptosis in ARPE-19 cells (a human RPE cell line) were investigated. We first confirmed that autophagy, ER stress and apoptosis in ARPE-19 cells were induced by Earle’s balanced salt solution (EBSS) through starvation to induce RPE metabolic stress. Secondly, inhibition of ER stress by 4-phenyl butyric acid (4-PBA) alleviated autophagy and apoptosis, and suppression of autophagy by 3-methyl adenine (3-MA) reduced the cell apoptosis, but the ER stress was minimally affected. Thirdly, the apoptosis, ER stress and autophagy were inhibited by gene silencing of calpain-2 and overexpression of calpain-1, respectively. Finally, taurine suppressed both the changes of the important upstream regulators (calpain-1 and calpain-2) and the activation of ER stress, autophagy and apoptosis, and taurine had protective effects on the survival of ARPE-19 cells. Collectively, this data indicate that taurine inhibits starvation-triggered endoplasmic reticulum stress, autophagy, and apoptosis in ARPE-19 cells by modulating the expression of calpain-1 and calpain-2.

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Section: Discussionmentioning

confidence: 99%

Inhibition of Starvation-Triggered Endoplasmic Reticulum Stress, Autophagy, and Apoptosis in ARPE-19 Cells by Taurine through Modulating the Expression of Calpain-1 and Calpain-2

Zhang

Ren

Liu

et al. 2017

IJMS

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“…Hence, while Lf isolated from human donors of 18–29 years old decreased phagocytosis of POS by 10 and 30% when ARPE‐19 cells when irradiated with blue light for 2 and 3 h, respectively, Lf from donors of 50–59 years old, inhibited the phagocytosis in that case by 20 and 60% . The observed photoinhibition of the phagocytic activity of ARPE‐19 cells, most likely results from sub‐lethal damage of the cell phagocytic apparatus, induced by photodynamic action mediated by an appropriate photosensitizer or by reactive oxygen species accompanying oxidative stress …”

Section: Resultsmentioning

confidence: 94%

“…To quantify the cytotoxic effect of photic stress in ARPE‐19 cells, MTT assay for mitochondrial redox function was used 24 h after the cell irradiation . According to the protocol, MTT solution (final concentration 0.5 mg mL −1 ) in MEM with 10% FBS was added to light treated cultures incubated with HBSS alone (control) or fed with LUV.…”

Section: Methodsmentioning

confidence: 99%

“…The effect of oxidative stress on specific phagocytic activity of the ARPE‐19 cells was determined by challenging light treated cultures incubated with HBSS (control) or LUV with fluorescent labelled bovine photoreceptor outer segments (POS‐FITC) according to previously described protocol . Briefly, control and photodynamically‐treated cells were challenged 30 min after light irradiation with FITC‐labeled POS (3.2 × 10 8 POS/mL) in MEM with 10% FBS, incubated for 5.5 h at 37 °C, then washed three times in PBS.…”

Section: Methodsmentioning

confidence: 99%

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Oxidized Lipids Decrease Phagocytic Activity of ARPE‐19 Cells In Vitro

Pawlak

Olchawa

Kościelniak

et al. 2019

Euro J Lipid Sci & Tech

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Phospholipids, representing 80% of retinal lipids, contain a high level of polyunsaturated fatty acids, which are susceptible to oxidation. It has recently been shown that Folch’ extract of bovine neural retinas reveals moderate photoreactivity by generating reactive oxygen species upon irradiation with blue light. Importantly, the photoreactivity markedly increases upon oxidation of the exctracted lipids. In this work, the phototoxic potential of the Folch’ extract of bovine neural retinas (BRex), subjected to controlled oxidation, is studied in vitro employing a retinal pigment epithelium cell line (ARPE‐19). Multilamellar liposomes prepared from BRex, equilibrated with air, are oxidized in the dark at 37 °C for up to 400 h. The liposomes are then introduced into ARPE‐19 cells by phagocytosis. The impact of BRex at different stages of oxidation on viability and specific phagocytic activity of ARPE‐19 cells exposed to visible light is analyzed. While the oxidized BRex, at the light doses employed, does not induce any measurable killing of the cells, the treatment noticeably decreases their specific phagocytic activity. Practical Applications: Lipid oxidation products are commonly considered as an efficient protein modification factor occurring in the retina. Although possible consequences of oxidation of retinal lipids for the onset and development of age‐related macular degeneration are widely discussed, their potential photoreactivity and possible phototoxicity have not been considered. This is an important issue; taking into account that reactive products of lipid oxidation present in the outer retina, it may be exposed to short‐wavelength visible radiation. If photoreactive, peroxidized retinal lipids may act as acquired endogenous sensitizers increasing the risk of retina photodamage. In this work, the phototoxic potential of the Folch’ extract of bovine neural retinas (BRex), subjected to controlled oxidation, is studied in vitro employing a retinal pigment epithelium cell line (ARPE‐19). Lipids present in the retina are characterized by high level of unsaturation that makes them susceptible to oxidation. When oxidized, retinal lipids become photoreactive under visible light. Treatment of retinal pigment epithelium cells (ARPE‐19) with liposomes prepared from oxidized Folch’ extract of bovine neural retinas followed by irradiation with visible light, reduces phagocytic activity of ARPE‐19 cells.

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“…Indeed, longterm responses to phagocytosis or oxidative stress share common features in human RPE (44). However, an inhibitory effect of reactive oxygen intermediates on phagocytosis has also been observed (45). Considering the dynamic nature of phosphorylation events, we can speculate that the role of particular phosphorylation cascades changes as the phagocytic process progresses, possibly as different stimuli reach the phagocytosing cell.…”

Section: Rpe-j Cellsmentioning

confidence: 90%

Quantitative phosphoproteomics reveals involvement of multiple signaling pathways in early phagocytosis by the retinal pigmented epithelium

Chiang

Tworak²,

Kevany³

et al. 2017

Journal of Biological Chemistry

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One of the major biological functions of the retinal pigmented epithelium (RPE) is the clearance of shed photoreceptor outer segments (POS) through a multistep process resembling phagocytosis. RPE phagocytosis helps maintain the viability of photoreceptors that otherwise could succumb to the high metabolic flux and photo-oxidative stress associated with visual processing. The regulatory mechanisms underlying phagocytosis in the RPE are not fully understood, although dysfunction of this process contributes to the pathogenesis of multiple human retinal degenerative disorders, including age-related macular degeneration. Here, we present an integrated transcriptomic, proteomic, and phosphoproteomic analysis of phagocytosing RPE cells, utilizing three different experimental models: the human-derived RPE-like cell line ARPE-19, cultured murine primary RPE cells, and RPE samples from live mice. Our combined results indicated that early stages of phagocytosis in the RPE are mainly characterized by pronounced changes in the protein phosphorylation level. Global phosphoprotein enrichment analysis revealed involvement of PI3K/Akt, mechanistic target of rapamycin (mTOR), and MEK/ERK pathways in the regulation of RPE phagocytosis, confirmed by immunoblot analyses and phagocytosis assays. Most strikingly, phagocytosis of POS by cultured RPE cells was almost completely blocked by pharmacological inhibition of phosphorylation of Akt. Our findings, along with those of previous studies, indicate that these phosphorylation events allow the RPE to integrate multiple signals instigated by shed POS at different stages of the phagocytic process.

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Inhibition of phagocytic activity of ARPE-19 cells by free radical mediated oxidative stress

Cited by 17 publications

References 55 publications

Inhibition of Starvation-Triggered Endoplasmic Reticulum Stress, Autophagy, and Apoptosis in ARPE-19 Cells by Taurine through Modulating the Expression of Calpain-1 and Calpain-2

Inhibition of Starvation-Triggered Endoplasmic Reticulum Stress, Autophagy, and Apoptosis in ARPE-19 Cells by Taurine through Modulating the Expression of Calpain-1 and Calpain-2

Oxidized Lipids Decrease Phagocytic Activity of ARPE‐19 Cells In Vitro

Quantitative phosphoproteomics reveals involvement of multiple signaling pathways in early phagocytosis by the retinal pigmented epithelium

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