Maduramicin induces apoptosis and necrosis, and blocks autophagic flux in myocardial H9c2 cells

Abstract

Maduramicin, a polyether ionophore antibiotic, is widely used as an anticoccidial agent in the poultry industry. It has been reported that maduramicin may cause heart and skeletal muscle cell damage, resulting in heart failure, skeletal muscle degeneration and even death in animals and humans, if improperly used. However, the molecular mechanism behind its capability to cause death of cardiac cells is not known. Here, we show that maduramicin induced apoptosis and necrosis in rat myocardial cells (H9c2). Maduramicin did not apparently upregulate the expression of pro-apoptotic proteins (e.g., BAD, BAK and BAX) or downregulate the expression of anti-apoptotic proteins (e.g. Bcl-2, Bcl-xL, Mcl-1 and survivin). Interestingly, maduramicin increased the expression of DR4 and TRAIL, activating caspases 8/3 and triggering cleavage of poly ADP ribose polymerase (PARP). In addition, maduramicin induced nuclear translocation of apoptosis inducing factor. Furthermore, maduramicin blocked autophagic flux, as evidenced by inducing accumulation of both LC3-II and p62/SQSTM1. Taken together, the above results suggest that maduramicin executes its toxicity in the myocardial cells at least by inducing caspase-dependent cell death through TRAIL/DR4-mediated extrinsic pathway and caspase-independent cell death by inducing apoptosis inducing factor nuclear translocation and blocking autophagic flux. Our findings provide a new insight into the molecular mechanism of maduramicin's toxicity in myocardial cells.

Maduramicin induces cardiotoxicity via Rac1 signaling‐independent methuosis in H9c2 cells

“…We herein report cytoplasmic vacuolization‐related methuosis in mammalian cell line (H9c2) induced by the toxic drug maduramicin, which frequently causes intoxication of target and nontarget animals (Britzi et al, 2017; Shimshoni et al, 2014; Singh & Gupta, 2003) as well as humans who ingested this drug accidently (Sharma et al, 2005). However, our previous findings demonstrate that apoptotic and non‐apoptotic cell death mediates maduramicin‐induced cardiotoxicity in vitro model using H9c2 cells (Chen, Chen, et al, 2018). Maduramicin‐triggered non‐apoptosis puzzled us for a long period until we found this unique phenotype “cytoplasmic vacuolization,” which occurred along with cytotoxicity.…”

Nanotherapeutics against malaria: A decade of advancements in experimental models

“…The median survival time exceeded 40 days for both strains, compared to only 27 days in the group receiving the free drug (Rajendran et al, 2018). Following the same line, maduramicin, an ionophore antibiotic with good gametocytocidal activity (Sun et al, 2014) but of high toxicity and lipophilic character (Chen et al, 2018), was incorporated in SPC‐Chol and PEGylated liposomes, (Raza et al, 2018). The PEGylated liposomal formulations (Table 1) not only prevented the unwanted toxic side effects of this drug but also showed IC 50 values of 1.25 and 1.20 ng/mL in P .…”

Ionophore Toxicity in Animals: A Review of Clinical and Molecular Aspects

“…In chickens, the approved dose of maduramicin is 5 mg/kg [ 70 ], but such a dose can be toxic in chickens. Five ppm and 10 ppm doses of maduramicin were applied to chickens, and they were considered safe during the first seven days of the administration.…”

“…Using rat myocardial cell lines, Chen et al showed that maduramicin induced apoptosis via caspase-dependent and independent mechanisms, necrosis, and autophagy in a dose-dependent manner [ 70 ]. These in vitro studies showed that the mechanisms of maduramicin toxicity could follow the same molecular patterns in myocardial cells.…”