Engineered Circular RNA Sponges Act as miRNA Inhibitors to Attenuate Pressure Overload-Induced Cardiac Hypertrophy

Abstract

Circular RNAs (circRNAs) sequester microRNAs (miRNAs) and repress their endogenous activity. We hypothesized that artificial circRNA sponges (circmiRs) can be constructed to target miRNAs therapeutically, with a low dosage requirement and extended half-lives compared to current alternatives. This could present a new treatment approach for critical global pathologies, including cardiovascular disease. Here, we constructed a circmiR sponge to target known cardiac pro-hypertrophic miR-132 and -212. Expressed circmiRs competitively inhibited miR-132 and -212 activity in luciferase rescue assays and showed greater stability than linear sponges. A design containing 12 bulged binding sites with 12 nucleotides spacing was determined to be optimal. Adeno-associated viruses (AAVs) were used to deliver circmiRs to cardiomyocytes in vivo in a transverse aortic constriction (TAC) mouse model of cardiac disease. Hypertrophic disease characteristics were attenuated, and cardiac function was preserved in treated mice, demonstrating the potential of circmiRs as novel therapeutic tools. Subsequently, group I permutated intron-exon sequences were used to directly synthesize exogenous circmiRs, which showed greater in vitro efficacy than the current gold standard antagomiRs in inhibiting miRNA function. Engineered circRNAs thus offer exciting potential as future therapeutics.

CircRNA—Protein Interactions in Muscle Development and Diseases

“…Currently, a few studies have preliminarily used circRNA for disease treatment. Lavenniah et al constructed a circRNA sponge (circmiR) that can target the degradation of miR-132/212 family in vitro; after delivering circmiR to cardiomyocytes, the hypertrophy is weakened, and cardiac function is stable [ 111 ]. Moreover, Yang et al used rabies virus glycoprotein-circSCMH1-extracellular vesicles to selectively deliver circSCMH1 to the brain; circSCMH1 binds to methyl-CpG binding protein 2 (MeCP2) and blocks MeCP2 transporting to the nucleus, promoting the expression of downstream target genes of MeCP2, enhancing neuronal plasticity, and effectively improving the functional recovery after stroke in mice and monkeys [ 112 ].…”

The Potential Regulatory Roles of Circular RNAs in Tumor Immunology and Immunotherapy

“…In speaking of translational study of circRNAs, one study suggested that artificially designed circRNA could act as a miRNA sponge to sequester miR-122, which plays an important role in the transfer of hepatitis, to inhibit the replication of HCV ( 143 ). And another study showed that artificially designed circRNA sponging miR-132 and miR-212 could attenuate pressure overloaded-induced cardiac hypertrophy ( 144 ). These studies show a great potential for translational application of circRNAs.…”

CircRNAs: Emerging Bladder Cancer Biomarkers and Targets

“…These results suggested that BC can be treated by synthesizing related circRNAs sponges. Recently, synthetic circRNA presented a new treatment approach for critical global pathologies, including cardiovascular disease, hepatitis, esophageal carcinoma, and Gastric Carcinoma ( 91 – 94 ). These findings establish that the design and construction of highly efficient artificial circRNAs sponges represent a novel strategy in the treatment of cancer and other diseases.…”