Premium
Mitochondrial Fragmentation and Mitophagy Contribute to Doxorubicin‐induced Cardiomyocyte Death
Author(s) -
Catanzaro Michael,
Kobayashi Satoru,
Gerdes Martin,
Liang Qiangrong
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.1036.12
Subject(s) - mitophagy , apoptosis , autophagy , propidium iodide , gene knockdown , programmed cell death , fragmentation (computing) , microbiology and biotechnology , chemistry , doxorubicin , mitochondrion , mitochondrial fission , dna fragmentation , transfection , biology , cancer research , cell culture , biochemistry , ecology , genetics , chemotherapy
Objectives Doxorubicin (DOX) is a widely used and highly effective chemotherapeutic antineoplastic agent that can cause severe cardiotoxicity. Previous studies have demonstrated that DOX‐induced cardiomyocyte (CM) death is accompanied by excessive mitochondrial (MT) fragmentation. However, it is unclear if this MT fragmentation mediates DOX‐induced cardiomyocyte damage. This study aimed to determine whether or not inhibiting MT fragmentation can reduce DOX‐induced CM death, and whether changes in MT autophagic degradation (mitophagy) are involved. Methods H9c2 cardiac myoblast cells were transfected with siRNA targeting DRP‐1, a protein required for MT fission, before DOX administration. Changes in MT morphology and mitophagy were monitored with confocal microscopy after infection with the adenovirus encoding mitochondria‐targeting reporter MitoDsRed or MitoRosella. Propidium iodide (PI) staining was used to quantify the extent of DOX‐induced cell injury, while protein expression levels of apoptotic markers, cleaved Caspase‐3 and cleaved PARP, were measured with western blotting. Results Morphometric analysis demonstrated that DRP‐1 knockdown with siRNA markedly diminished DOX‐induced MT fragmentation as shown by form factor , aspect ratio , and mitochondrial size. This led to reduced CM death as shown by percentage of PI‐positive cells, caspase‐3 cleavage, and PARP cleavage. DRP‐1 knockdown also attenuated DOX‐induced mitophagy as assessed by the dual fluorescent mitophagy reporter MitoRosella. Conclusion These results suggest that DOX‐induced cardiotoxicity may be due to excessive mitochondrial fragmentation and degradation through autophagy.