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AICAR induces effectively autophagy clearance in ARPE‐19 cells
Author(s) -
KAARNIRANTA K,
VIIRI J,
HYTTINEN J,
SALMINEN A
Publication year - 2012
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2012.4481.x
Subject(s) - autophagy , bafilomycin , sequestosome 1 , microbiology and biotechnology , atg5 , proteasome , lysosome , chemistry , confocal microscopy , organelle , atg12 , lamp1 , proteasome inhibitor , activator (genetics) , apoptosis , biology , biochemistry , gene , enzyme
Purpose The ubiquitin‐proteasome pathway and lysosomal pathway including autophagy are the master clearance systems in cells. The p62/sequestosome 1 (p62) and LC3 have been observed to be key players linking the proteasomal and lysosomal clearance systems. In this study, crosstalk of proteasomes and autophagy was examined. Methods Effect of autophagy activator (AICAR) and inhibitor (bafilomycin) on protein aggregation and autophagy markers were studied in the ARPE‐19 cells treated with proteasome inhibitor (MG‐132, 5µM) with or without AICAR (2mM) or bafilomycin (50nM) for 24h hours. Autophagy gene activation was studied by cDNA PCR array. The protein levels of LC3 were evaluated by western blotting. The localization and movement of p62 and LC3 were analyzed by live confocal microscopy. Cellular organelles were visualized by transmission electron microscopy. Results MG‐132 clearly increased perinuclear protein aggregation, while AICAR robustly decreased the amount of aggregates together with LC3 activation. AICAR upregulates the most important autophagy genes. We show that p62 and LC3 colocalizes with the protein aggregates that all are finally degraded in autophagy. Conclusion Autophagy is effective clearance machine in RPE cells that might be a novel therapy target to prevent cell degeneration.