Genetic profiling of fatty acid desaturase polymorphisms identifies patients who may benefit from high-dose omega-3 fatty acids in cardiac remodeling after acute myocardial infarction-Post-hoc analysis from the OMEGA-REMODEL randomized controlled trial.

BACKGROUND: The double-blind OMEGA-REMODEL placebo-controlled randomized trial of high-dose omega-3 fatty acids (O-3FA) post-acute myocardial infarction (AMI) reported improved cardiac remodeling and attenuation of non-infarct myocardial fibrosis. Fatty acid desaturase 2 (FADS2) gene cluster encodes key enzymes in the conversion of essential omega-3 and omega-6 fatty acids into active arachidonic (ArA) and eicosapentaenoic acids (EPA), which influence cardiovascular outcomes. METHODS AND RESULTS: We tested the hypothesis that the genotypic status of FADS2 (rs1535) modifies therapeutic response of O-3FA in post-AMI cardiac remodeling in 312 patients. Consistent with known genetic polymorphism of FADS2, patients in our cohort with the guanine-guanine (GG) genotype had the lowest FADS2 activity assessed by arachidonic acid/linoleic acid (ArA/LA) ratio, compared with patients with the adenine-adenine (AA) and adenine-guanine (AG) genotypes (GG:1.62±0.35 vs. AA: 2.01±0.36, p<0.0001; vs. AG: 1.76±0.35, p = 0.03). When randomized to 6-months of O-3FA treatment, GG patients demonstrated significant lowering of LV end-systolic volume index (LVESVi), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and galectin-3 levels compared to placebo (-4.4 vs. 1.2 ml/m2, -733 vs. -181 pg/mL, and -2.0 vs. 0.5 ng/mL; p = 0.006, 0.006, and 0.03, respectively). In contrast, patients with either AA or AG genotype did not demonstrate significant lowering of LVESVi, NT-proBNP, or galectin-3 levels from O-3FA treatment, compared to placebo. The odds ratios for improving LVESVi by 10% with O-3FA treatment was 7.2, 1.6, and 1.2 in patients with GG, AG, and AA genotypes, respectively. CONCLUSION: Genetic profiling using FADS2 genotype can predict the therapeutic benefits of O-3FA treatment against adverse cardiac remodeling during the convalescent phase of AMI. CLINICAL TRIAL REGISTRATION INFORMATION: clinicaltrials.gov Identifier: NCT00729430.

Yin Yang 1 Suppresses Dilated Cardiomyopathy and Cardiac Fibrosis Through Regulation of Bmp7 and Ctgf.

RATIONALE: Pathogenic variations in the lamin gene (LMNA) cause familial dilated cardiomyopathy (DCM). LMNA insufficiency caused by LMNA pathogenic variants is believed to be the basic mechanism underpinning LMNA-related DCM. OBJECTIVE: To assess whether silencing of cardiac Lmna causes DCM and investigate the role of Yin Yang 1 (Yy1) in suppressing Lmna DCM. METHODS AND RESULTS: We developed a Lmna DCM mouse model induced by cardiac-specific Lmna short hairpin RNA. Silencing of cardiac Lmna induced DCM with associated cardiac fibrosis and inflammation. We demonstrated that upregulation of Yy1 suppressed Lmna DCM and cardiac fibrosis by inducing Bmp7 expression and preventing upregulation of Ctgf. Knockdown of upregulated Bmp7 attenuated the suppressive effect of Yy1 on DCM and cardiac fibrosis. However, upregulation of Bmp7 alone was not sufficient to suppress DCM and cardiac fibrosis. Importantly, upregulation of Bmp7 together with Ctgf silencing significantly suppressed DCM and cardiac fibrosis. Mechanistically, upregulation of Yy1 regulated Bmp7 and Ctgf reporter activities and modulated Bmp7 and Ctgf gene expression in cardiomyocytes. Downregulation of Ctgf inhibited TGF-ß (transforming growth factor-ß)/Smad signaling in DCM hearts. Regulation of both Bmp7 and Ctgf further suppressed TGFß/Smad signaling. In addition, co-modulation of Bmp7 and Ctgf reduced CD3+ T cell numbers in DCM hearts. CONCLUSIONS: Our findings demonstrate that upregulation of Yy1 or co-modulation of Bmp7 and Ctgf offer novel therapeutic strategies for the treatment of DCM caused by LMNA insufficiency.