Mitochondrial targeted antioxidants, mitoquinone and SKQ1, not vitamin C, mitigate doxorubicin-induced damage in H9c2 myoblast: pretreatment vs. co-treatment

Abstract

Background Preconditioning of the heart ameliorates doxorubicin (Dox)-induced cardiotoxicity. We tested whether pretreating cardiomyocytes by mitochondrial-targeted antioxidants, mitoquinone (MitoQ) or SKQ1, would provide better protection against Dox than co-treatment. Methods We investigated the dose-response relationship of MitoQ, SKQ1, and vitamin C on Dox-induced damage on H9c2 cardiomyoblasts when drugs were given concurrently with Dox (e.g., co-treatment) or 24 h prior to Dox (e.g., pretreatment). Moreover, their effects on intracellular and mitochondrial oxidative stress were evaluated by 2,7-dichlorofluorescin diacetate and MitoSOX, respectively. Results Dox (0.5–50 μM, n = 6) dose-dependently reduced cell viability. By contrast, co-treatment of MitoQ (0.05–10 μM, n = 6) and SKQ1 (0.05–10 μM, n = 6), but not vitamin C (1–2000 μM, n = 3), significantly improved cell viability only at intermediate doses (0.5–1 μM). MitoQ (1 μM) and SKQ1 (1 μM) significantly increased cell viability to 1.79 ± 0.12 and 1.59 ± 0.08 relative to Dox alone, respectively (both p < 0.05). Interestingly, when given as pretreatment, only higher doses of MitoQ (2.5 μM, n = 9) and SKQ1 (5 μM, n = 7) showed maximal protection and improved cell viability to 2.19 ± 0.13 and 1.65 ± 0.07 relative to Dox alone, respectively (both p < 0.01), which was better than that of co-treatment. Moreover, the protective effects were attributed to the significant reduction in Dox-induced intracellular and mitochondrial oxidative stress. Conclusion The data suggest that MitoQ and SKQ1, but not vitamin C, mitigated DOX-induced damage. Moreover, MitoQ pretreatment showed significantly higher cardioprotection than its co-treatment and SKQ1, which may be due to its better antioxidant effects.

Mitochondrial-Targeted Therapy for Doxorubicin-Induced Cardiotoxicity

“…Similarly, SKQ1, another mitochondria-targeted mimetic of coenzyme Q, can also be directed to the mitochondria via a similar strategy. All three compounds have demonstrated the ability to ameliorate the pathological phenotype of a range of diseases involving oxidative stress and can protect against DOX in animal models [154][155][156]. Clinical trials are ongoing to test if they confer similar benefits in patients.…”

Assessing Drug-Induced Mitochondrial Toxicity in Cardiomyocytes: Implications for Preclinical Cardiac Safety Evaluation

“…By sequential selective passaging and culturing with all-trans retinoic acid and 1% serum media, they may overexpress L-type calcium channels, mimicking the adult cardiac muscle phenotype [ 276 , 277 ]. H9c2 cardiomyoblasts have been used for mitochondrial toxicity assessment of DOX, and demonstrated increased mitochondrial swelling [ 278 ], mtROS [ 279 ], mitochondrial fission [ 280 ], decreased MMP [ 281 ], and OCR and ATP production [ 282 ], whereas trastuzumab led to increased mtROS and decreased MMP [ 185 ]. Treatment of H9c2 cells with tyrosine kinase inhibitors, such as imatinib, sorafenib, and sunitinib, resulted in mitochondrial swelling, cristae loss, MMP reduction, inhibition of MRC complexes, superoxide accumulation, and cellular GSH depletion [ 283 , 284 , 285 ].…”

“…H9c2 can be either self-differentiated or purchased from cell banks (e.g., American Tissue Culture Collection (Manassas, VA, USA) [ 185 , 279 ] and Cell Bank of the Type Culture Collection of the Chinese Academy of Sciences (Shanghai, China) [ 280 , 282 ]) and cultured with Dulbecco’s modified Eagle’s Medium (DMEM; Gibco) containing 10% fetal bovine serum (FBS; Gibco), 100 U/mL penicillin, and 100 μg/mL streptomycin. In addition, 2D hiPSC-CMs can be self-differentiated and cultured with RPMI + B27 with insulin [ 338 , 339 ], or purchased from biotechnology companies (e.g., Cellular Dynamics International (Madison, WI, USA) [ 308 ] and FUJIFILM Cellular Dynamics, Inc (FCDI, Madison, WI, USA) [ 309 ]), and maintained in culture according to their protocols.…”

Role of Mitochondrial Dysfunction in the Pathogenesis of Cisplatin-Induced Myotube Atrophy

“…In the current study, we aimed to elucidate the effects of cisplatin on mitochondrial functions, i.e., ATP production, cellular energy metabolism, ROS generation, and regulation of apoptosis in C2C12 myotubes. Further, the efficacy of the mitochondria-targeted antioxidant mitoquinone mesylate (MitoQ) [26][27][28][29] was examined to investigate the mechanism underlying mitochondrial disorder in cisplatin-induced myotube atrophy.…”