Project description:Diabetes leads to cardiomyopathy and heart failure, the leading cause of death for diabetic patients. Monoamine oxidase (MAO)-dependent reactive oxygen species (ROS) formation contributes to the development of diabetic cardiomyopathy by inducing mitochondrial and cardiomyocyte dysfunction. Yet, it is unclear whether, in addition to the direct effects exerted by MAO-dependent ROS on mitochondria, MAO activity is able to post-transcriptionally regulate cardiomyocyte function and survival in diabetes. To this aim, we performed gene and miRNA expression profiling in cardiac tissue from a mouse model of type 1 diabetes (T1D) with or without pharmacological MAO inhibition. We found that MAO-dependent ROS generation in T1D hearts leads to profound transcriptomic changes, affecting autophagy and pro-survival pathways activation. MAO activity in T1D hearts affected expression levels of miR-133a-3p, -193a-3p, and -27a-3p that target insulin-like growth factor receptor 1 (Igf1r), growth factor receptor bound protein 10 and inositol polyphosphate 4 phosphatase type 1A, respectively, all components of the Igf1r/PI3K/Akt signaling pathway. Indeed, Akt activation was significantly downregulated in T1D hearts, whereas MAO inhibition restored the activation of this pro-survival pathway. The present study provides an important link between MAO activity, transcriptomic changes, and activation of pro-survival signaling and autophagy in diabetic cardiomyopathy.
Project description:Diabetes leads to cardiomyopathy and heart failure, the leading cause of death for diabetic patients. Monoamine oxidase (MAO)-dependent reactive oxygen species (ROS) formation contributes to the development of diabetic cardiomyopathy by inducing mitochondrial and cardiomyocyte dysfunction. Yet, it is unclear whether, in addition to the direct effects exerted by MAO-dependent ROS on mitochondria, MAO activity is able to post-transcriptionally regulate cardiomyocyte function and survival in diabetes. To this aim, we performed gene and miRNA expression profiling in cardiac tissue from a mouse model of type 1 diabetes (T1D) with or without pharmacological MAO inhibition. We found that MAO-dependent ROS generation in T1D hearts leads to profound transcriptomic changes, affecting autophagy and pro-survival pathways activation. MAO activity in T1D hearts affected expression levels of miR-133a-3p, -193a-3p, and -27a-3p that target insulin-like growth factor receptor 1 (Igf1r), growth factor receptor bound protein 10 and inositol polyphosphate 4 phosphatase type 1A, respectively, all components of the Igf1r/PI3K/Akt signaling pathway. Indeed, Akt activation was significantly downregulated in T1D hearts, whereas MAO inhibition restored the activation of this pro-survival pathway. The present study provides an important link between MAO activity, transcriptomic changes, and activation of pro-survival signaling and autophagy in diabetic cardiomyopathy.
