PDE3A2 modRNA Fine-Tunes Nuclear cAMP Microdomains and Reverses Pathological Cardiac Hypertrophy

Pathological cardiac hypertrophy (PCH) is a precursor to heart failure, driven in part by dysregulated nuclear-localized cAMP (NLS-cAMP) signaling. Phosphodiesterase 3A2 (PDE3A2) is a key regulator of this nuclear cAMP microdomain, yet its selective modulation remains challenging. Here, we developed PDE3A2-modified RNA (PDE3A2-modRNA) to restore nuclear PDE3A2 levels and tested its efficacy in an angiotensin II-induced PCH model. Subcellular FRET imaging revealed that PCH hearts exhibit hyperactive NLS-cAMP due to PDE3A2 depletion. PDE3A2-modRNA selectively reduced NLS-cAMP without altering cytosolic cAMP, demonstrating precise microdomain regulation. In vivo, PDE3A2-modRNA improved cardiac function, attenuated hypertrophy and fibrosis, and shifted transcriptional programs toward physiological remodeling. Single-nucleus transcriptomics and immune profiling further revealed reduced oxidative stress and an improved cardiac microenvironment. These findings highlight PDE3A2-modRNA as a novel gene therapy that selectively restores nuclear cAMP homeostasis, reversing PCH-promoting transcriptional programs while preserving physiological cAMP signaling in cytosolic microdomains.