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Do antioxidants inhibit oxidative‐stress‐induced autophagy of tenofibroblasts?
Author(s) -
Kim RaJeong,
Hah YoungSool,
Sung ChangMeen,
Kang JaeRan,
Park Hyung Bin
Publication year - 2014
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1002/jor.22608
Subject(s) - autophagy , atg5 , programmed cell death , apoptosis , oxidative stress , microbiology and biotechnology , chemistry , viability assay , biology , biochemistry
Recent research on tendinopathy has focused on its relationship to programmed cell death. Increased autophagy has been observed in ruptured rotator cuff tendon tissues, suggesting a causal relationship. We investigated whether autophagy occurs in human rotator cuff tenofibroblast death induced by oxidative stress and whether antioxidants protect against autophagic cell death. We used H 2 O 2 (0.75 mM) as oxidative stressor, cyanidin (100 µg/ml) as antioxidant, zVAD (20 µM) as apoptosis inhibitor, and 3‐MA (10 mM) as autophagy inhibitor. We evaluated cell viability and known autophagic markers: LC3‐II expression, GFP‐LC3 puncta formation, autolysosomes, and Atg5‐12 and Beclin 1 expression. H 2 O 2 exposure increased the rates of cell death, LC3‐II expression, GFP‐LC3 puncta formation, and autolysosomes. After we induced apoptosis arrest using zVAD, H 2 O 2 exposure still induced cell death, LC3‐II expression, and GFP‐LC3 puncta formation. H 2 O 2 exposure also increased Atg5‐12 and Beclin 1 expressions, indicating autophagic cell death. However, cyanidin treatment reduced H 2 O 2 ‐induced cell death, LC3‐II expression, GFP‐LC3 puncta formation, and autolysosomes. Cyanidin and 3‐MA similarly reduced the cell‐death rate, and Atg5‐12 and Beclin 1 expression. This study demonstrated that H 2 O 2 , an oxidative stressor, induces autophagic cell death in rotator cuff tenofibroblasts, and that cyanidin, a natural antioxidant, inhibits autophagic cell death. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:937–943, 2014.