caa a22 4500 605543682 CHVBK 20210128100927.0 cr unu---uuuuu 210128e20150801xx s 000 0 eng 10.1007/s00109-015-1275-1 doi (NATIONALLICENCE)springer-10.1007/s00109-015-1275-1 Light induces NLRP3 inflammasome activation in retinal pigment epithelial cells via lipofuscin-mediated photooxidative damage [Elektronische Daten] [Carolina Brandstetter, Lena Mohr, Eicke Latz, Frank Holz, Tim Krohne] Photooxidative damage and chronic innate immune activation have been implicated in retinal pigment epithelium (RPE) dysfunction, a process that underlies blinding diseases such as age-related macular degeneration (AMD). To identify a potential molecular link between these mechanisms, we investigated whether lipofuscin-mediated phototoxicity activates the NLRP3 inflammasome in RPE cells in vitro. We found that blue light irradiation (dominant wavelength 448nm, irradiance 0.8mW/cm2, duration 6h) of lipofuscin-loaded primary human RPE cells and ARPE-19 cells induced photooxidative damage, lysosomal membrane permeabilization (79.5% of cells vs. 3.8% in nonirradiated controls), and cytosolic leakage of lysosomal enzymes. This resulted in activation of the inflammasome with activation of caspase-1 and secretion of interleukin-1β (14.6 vs. 0.9pg/ml in nonirradiated controls) and interleukin-18 (87.7 vs. 0.2pg/ml in nonirradiated controls). Interleukin secretion was dependent on the activity of NLRP3, caspase-1, and lysosomal proteases cathepsin B and L. These results demonstrate that accumulation of lipofuscin-like material in vitro renders RPE cells susceptible to phototoxic destabilization of lysosomes, resulting in NLRP3 inflammasome activation and secretion of inflammatory cytokines. This new mechanism of inflammasome activation links photooxidative damage and innate immune activation in RPE pathology and may provide novel targets for therapeutic intervention in retinal diseases such as AMD. Key message: • Visible light irradiation of lipofuscin-loaded RPE cells activates inflammasome. • Inflammasome activation results from lysosomal permeabilization and enzyme leakage. • Inflammasome activation induces secretion of inflammatory cytokines by RPE cells. • Photooxidative damage by visible light as new mechanism of inflammasome activation. • Novel link between hallmark pathogenetic features of retinal degenerative diseases. The Author(s), 2015 Age-related macular degeneration nationallicence Retinal pigment epithelium nationallicence Interleukin-1β nationallicence Lysosomal membrane permeabilization nationallicence Lipid peroxidation nationallicence A2E : N-retinylidene-N-retinyl-ethanolamine nationallicence AMD : Age-related macular degeneration nationallicence ASC : Apoptosis-associated speck-like protein containing a caspase recruitment domain (CARD) nationallicence CEP : Carboxyethylpyrrole nationallicence DABCO : 1,4-Diazabicyclooctane nationallicence FAM-YVAD-FMK : Carboxyfluorescein-Tyr-Val-Ala-Asp-fluoromethylketone nationallicence FLICA : Fluorochrome-labeled inhibitor of caspases nationallicence HNE : 4-Hydroxynonenal nationallicence IL : Interleukin nationallicence Leu-Leu-OMe : L-leucyl-L-leucine methyl ester nationallicence LPS : Lipopolysaccharide nationallicence MDA : Malondialdehyde nationallicence NLRP3 : Nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family, pyrin domain-containing protein 3 nationallicence POS : Photoreceptor outer segments nationallicence RPE : Retinal pigment epithelium nationallicence Z-FF-FMK : Z-Phe-Phe-fluoromethylketone nationallicence Z-YVAD-FMK : Z-Tyr-Val-Ala-Asp-fluoromethylketone nationallicence Brandstetter Carolina Department of Ophthalmology, University of Bonn, Ernst-Abbe-Str. 2, 53127, Bonn, Germany aut Mohr Lena Department of Ophthalmology, University of Bonn, Ernst-Abbe-Str. 2, 53127, Bonn, Germany aut Latz Eicke Institute of Innate Immunity, University of Bonn, Bonn, Germany aut Holz Frank Department of Ophthalmology, University of Bonn, Ernst-Abbe-Str. 2, 53127, Bonn, Germany aut Krohne Tim Department of Ophthalmology, University of Bonn, Ernst-Abbe-Str. 2, 53127, Bonn, Germany aut Journal of Molecular Medicine Springer Berlin Heidelberg 93/8(2015-08-01), 905-916 0946-2716 93:8<905 2015 93 109 https://doi.org/10.1007/s00109-015-1275-1 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00109-015-1275-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Brandstetter Carolina Department of Ophthalmology, University of Bonn, Ernst-Abbe-Str. 2, 53127, Bonn, Germany aut NATIONALLICENCE 700 1- Mohr Lena Department of Ophthalmology, University of Bonn, Ernst-Abbe-Str. 2, 53127, Bonn, Germany aut NATIONALLICENCE 700 1- Latz Eicke Institute of Innate Immunity, University of Bonn, Bonn, Germany aut NATIONALLICENCE 700 1- Holz Frank Department of Ophthalmology, University of Bonn, Ernst-Abbe-Str. 2, 53127, Bonn, Germany aut NATIONALLICENCE 700 1- Krohne Tim Department of Ophthalmology, University of Bonn, Ernst-Abbe-Str. 2, 53127, Bonn, Germany aut NATIONALLICENCE 773 0- Journal of Molecular Medicine Springer Berlin Heidelberg 93/8(2015-08-01), 905-916 0946-2716 93:8<905 2015 93 109