MiR-150 blunts cardiac dysfunction in mice with cardiomyocyte loss of β 1 -adrenergic receptor/β-arrestin signaling and controls a unique transcriptome.

The β 1 -adrenergic receptor (β 1 AR) is found primarily in hearts (mainly in cardiomyocytes [CMs]) and β-arrestin-mediated β 1 AR signaling elicits cardioprotection through CM survival. We showed that microRNA-150 (miR-150) is upregulated by β-arrestin-mediated β 1 AR signaling and that CM miR-150 inhibits maladaptive remodeling post-myocardial infarction. Here, we investigate whether miR-150 rescues cardiac dysfunction in mice bearing CM-specific abrogation of β-arrestin-mediated β 1 AR signaling. Using CM-specific transgenic (TG) mice expressing a mutant β 1 AR (G protein-coupled receptor kinase [GRK] - β 1 AR that exhibits impairment in β-arrestin-mediated β 1 AR signaling), we first generate a novel double TG mouse line overexpressing miR-150. We demonstrate that miR-150 is sufficient to improve cardiac dysfunction in CM-specific GRK - β 1 AR TG mice following chronic catecholamine stimulation. Our genome-wide circular RNA, long noncoding RNA (lncRNA), and mRNA profiling analyses unveil a subset of cardiac ncRNAs and genes as heretofore unrecognized mechanisms for beneficial actions of β 1 AR/β-arrestin signaling or miR-150. We further show that lncRNA Gm41664 and GDAP1L1 are direct novel upstream and downstream regulators of miR-150. Lastly, CM protective actions of miR-150 are attributed to repressing pro-apoptotic GDAP1L1 and are mitigated by pro-apoptotic Gm41664. Our findings support the idea that miR-150 contributes significantly to β 1 AR/β-arrestin-mediated cardioprotection by regulating unique ncRNA and gene signatures in CMs.