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Doxorubicin (DOX) is an anthracycline antibiotic commonly employed for the treatment of various cancers. However, its therapeutic uses are hampered by side effects associated with cumulative doses during the course of treatment. Whereas deregulation of autophagy in the myocardium has been involved in a variety of cardiovascular diseases, the role of autophagy in DOX-induced cardiomyopathy remains debated. Our earlier studies have shown that DOX treatment in a rat animal model leads to increased expression of the novel stress-inducible protein insulin-like growth factor II receptor- (IGF-IIR) in cardiac tissues, which exacerbated the cardiac injury by enhancing oxidative stress and p53-mediated mitochondria-dependent cardiac apoptosis. Through this study, we investigated the contribution of IGF-IIR to dysregulation of autophagy in heart using both in vitro H9c2 cells (DOX treated, 1 M) and in vivo transgenic rat models (DOX treated, 5 mg/kg ip for 6 wk) overexpressing IGF-IIR specifically in the heart. We found that IGF-IIR primarily localized to mitochondria, causing increased mitochondrial oxidative stress that was severely aggravated by DOX treatment. This was accompanied by a significant perturbation in mitochondrial membrane potential and increased leakage of cytochrome c, causing increased cleaved caspase-3 activity. There were significant alterations in phosphorylated AMP-activated protein kinase (p-AMPK), phosphorylated Unc-51 like kinase-1 (p-ULK1), PARKIN, PTENinduced kinase 1 (PINK1), microtubule-associated protein 1 light chain 3 (LC3), and p62 proteins, which were more severely disrupted under the combined effect of IGF-IIR overexpression plus DOX. Finally, LysoTracker Red staining showed that IGF-IIR overexpression causes lysosomal impairment, which was rescued by rapamycin treatment. Taken together, we found that IGF-IIR leads to mitochondrial oxidative stress, decreased antioxidant levels, disrupted mitochondrial membrane potential, and perturbed mitochondrial autophagy contributing to DOX-induced cardiomyopathy. [ABSTRACT FROM AUTHOR]

The present study tests a hypothesis that cardioprotective effects mediated by autologous adipose-derived stem cells (ADSC) in rats afflicted with insulin-dependent diabetes mellitus (IDDM) may be synergistically enhanced by oral treatment with green tea epigallocatechin gallate (EGCG). Wistar rats were divided into sham, DM, DM+ ADSC (autologous transplanted 1 × 106 cells per rat), and DM+ ADSC+E (E, green tea oral administration EGCG). Heart tissues were isolated from all rats, and investigations were performed after 2-mo treatment. In the sham, DM, and DM+ADSC groups, we found that DM induced cardiac dysfunction (sham and DM) and autologous ADSC transplantation could partially recover cardiac functions (DM and DM+ADSC) in DM rats. Compared with DM+ADSC, significant improvement in cardiac functions can be observed in DM+ADSC+E in echocardiographic data, histological observations, and even cellular protein expression. Oral green tea EGCG administration and autologous ADSC transplantation show synergistically beneficial effects on diabetic cardiac myopathy in DM rats. [ABSTRACT FROM AUTHOR]