Novel Role for Pleckstrin Homology‐Like Domain Family A, Member 3 in the Regulation of Pathological Cardiac Hypertrophy

BACKGROUND: Pleckstrin homology‐like domain family A, member 3 (PHLDA3), a crucial member of the PHLDA family, is involved in tumor suppression, kidney injury, liver injury, and glucose metabolism. However, the role of PHLDA3 in pathological cardiac hypertrophy and heart failure remains unclear. METHODS AND RESULTS: In the present study, PHLDA3 expression was downregulated in hypertrophic murine hearts and angiotensin II‐treated cardiomyocytes. Next, an in vitro study suggested, by using gain‐ and loss‐of‐function approaches, that PHLDA3 attenuates Ang II exposure‐induced cardiomyocyte hypertrophy. Consistent with the cell phenotype, disruption of PHLDA3 aggravated the effects of pressure overload‐induced pathological cardiac hypertrophy, fibrosis, and dysfunction. In contrast, PHLDA3 overexpression resulted in an attenuated hypertrophic phenotype. Molecular analysis revealed that PHLDA3 suppressed the activation of AKT‐mTOR‐GSK3β‐P70S6K signaling in response to hypertrophic stress, and the blockage of AKT activation rescued these adverse pathological effects of PHLDA3 deficiency‐induced by AB and Ang II, respectively, in vivo and in vitro. CONCLUSIONS: Collectively, our data indicated that PHLDA3 could ameliorate pressure overload‐induced cardiac remodeling mainly by blocking the AKT signaling pathway, suggesting that PHLDA3 may represent a therapeutic target for the treatment of pathological cardiac hypertrophy and heart failure.