MicroRNA-146a is a therapeutic target and biomarker for peripartum cardiomyopathy
Julie Halkein, … , Denise Hilfiker-Kleiner, Ingrid Struman
Julie Halkein, … , Denise Hilfiker-Kleiner, Ingrid Struman
Published April 24, 2013
Citation Information: J Clin Invest. 2013;123(5):2143-2154. https://doi.org/10.1172/JCI64365.
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Research Article

MicroRNA-146a is a therapeutic target and biomarker for peripartum cardiomyopathy

Abstract

Peripartum cardiomyopathy (PPCM) is a life-threatening pregnancy-associated cardiomyopathy in previously healthy women. Although PPCM is driven in part by the 16-kDa N-terminal prolactin fragment (16K PRL), the underlying molecular mechanisms are poorly understood. We found that 16K PRL induced microRNA-146a (miR-146a) expression in ECs, which attenuated angiogenesis through downregulation of NRAS. 16K PRL stimulated the release of miR-146a–loaded exosomes from ECs. The exosomes were absorbed by cardiomyocytes, increasing miR-146a levels, which resulted in a subsequent decrease in metabolic activity and decreased expression of Erbb4, Notch1, and Irak1. Mice with cardiomyocyte-restricted Stat3 knockout (CKO mice) exhibited a PPCM-like phenotype and displayed increased cardiac miR-146a expression with coincident downregulation of Erbb4, Nras, Notch1, and Irak1. Blocking miR-146a with locked nucleic acids or antago-miRs attenuated PPCM in CKO mice without interrupting full-length prolactin signaling, as indicated by normal nursing activities. Finally, miR-146a was elevated in the plasma and hearts of PPCM patients, but not in patients with dilated cardiomyopathy. These results demonstrate that miR-146a is a downstream-mediator of 16K PRL that could potentially serve as a biomarker and therapeutic target for PPCM.

Authors

Julie Halkein, Sebastien P. Tabruyn, Melanie Ricke-Hoch, Arash Haghikia, Ngoc-Quynh-Nhu Nguyen, Michaela Scherr, Karolien Castermans, Ludovic Malvaux, Vincent Lambert, Marc Thiry, Karen Sliwa, Agnes Noel, Joseph A. Martial, Denise Hilfiker-Kleiner, Ingrid Struman

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Figure 2

NRAS is a target gene of miR-146a in HUVECs.

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NRAS is a target gene of miR-146a in HUVECs. (A) NRAS mRNA (qRT-PCR) ...
(A) NRAS mRNA (qRT-PCR) and (B) protein levels (Western blot) in HUVECs transfected with pre-miR-146a and pre-miR-control. (C) Luciferase activity from NRAS 3′UTR WT reporter plasmid and mutated NRAS 3′UTR cotransfected into HEK293T cells with pre-miR-146a or pre-miR-control 48 hours after transfection. (D) BrdU incorporation, (E) FACS analysis for apoptosis by annexin V–PI staining, and (F) DNA fragmentation analysis in HUVECs transfected with NRAS or control siRNA for 48 hours. (G) Representative images of laser-induced choroidal neovascularization 7 days after transfection with NRAS or control siRNA injected intravitreously (n ≥ 8 eyes/condition; 4 lesions/eyes). Dashed outlines denote lesion area. Scale bars: 100 μm. (H) Quantification (by ImageJ) of the green signal present in lesion area. CNV, choroidal neovascularization. (I) NRAS mRNA level in HUVECs stimulated with 16K PRL (50 nM, 8 hours), with pretransfection (48 hours) with anti-miR-control or anti-miR-146a. All data are mean ± SD (n ≥ 3) or mean ± SEM (H). *P < 0.05 vs. respective control. See also Supplemental Figure 2.