Brain natriuretic peptide in pregnant women with heart disease.

BACKGROUND: Plasma brain natriuretic peptide levels were prospectively studied in pregnant women with heart disease. METHODS: Fifty pregnant women with heart disease and 25 controls were evaluated at 24 weeks or under, 30-32 weeks, 34 weeks or more of gestation, and 6 weeks postpartum. Adverse maternal cardiac events were hospitalization for worsening heart failure, stroke, and death. RESULTS: Thirty-eight (76%) women had rheumatic heart disease. Plasma brain natriuretic peptide levels were (in cases and controls) 118.3 ± 46.5 pg/ml and 66.3 ± 15.9 pg/ml (at 24 weeks or under), 124.8 ± 30.4 pg/ml and 68.4 ± 16.5 pg/ml (30-32 weeks), 135.8 ± 34.9 pg/ml and 68.6 ± 15.6 pg/ml (34 weeks or more), and 110.1 ± 21.9 pg/ml and 65.0 ± 16.1 pg/ml (6 weeks postpartum) (p = .0001). Eighteen women had adverse events. Of these, only 1 had a level less than 100 pg/ml, 12 were between 100 and 200 pg/ml, and 5 more than 200 pg/ml. CONCLUSIONS: Plasma brain natriuretic peptide levels were higher in women with heart disease at all periods of gestation as well as six weeks postpartum. No woman with a plasma brain natriuretic peptide levels of 98 pg/ml or less had an adverse event.

Myocardin ablation in a cardiac-renal rat model.

Cardiorenal syndrome is defined by primary heart failure conditions influencing or leading to renal injury or dysfunction. Dilated cardiomyopathy (DCM) is a major co-existing form of heart failure (HF) with renal diseases. Myocardin (MYOCD), a cardiac-specific co-activator of serum response factor (SRF), is increased in DCM porcine and patient cardiac tissues and plays a crucial role in the pathophysiology of DCM. Inhibiting the increased MYOCD has shown to be partially rescuing the DCM phenotype in porcine model. However, expression levels of MYOCD in the cardiac tissues of the cardiorenal syndromic patients and the effect of inhibiting MYOCD in a cardiorenal syndrome model remains to be explored. Here, we analyzed the expression levels of MYOCD in the DCM patients with and without renal diseases. We also explored, whether cardiac specific silencing of MYOCD expression could ameliorate the cardiac remodeling and improve cardiac function in a renal artery ligated rat model (RAL). We observed an increase in MYOCD levels in the endomyocardial biopsies of DCM patients associated with renal failure compared to DCM alone. Silencing of MYOCD in RAL rats by a cardiac homing peptide conjugated MYOCD siRNA resulted in attenuation of cardiac hypertrophy, fibrosis and restoration of the left ventricular functions. Our data suggest hyper-activation of MYOCD in the pathogenesis of the cardiorenal failure cases. Also, MYOCD silencing showed beneficial effects by rescuing cardiac hypertrophy, fibrosis, size and function in a cardiorenal rat model.

Correction to: ACE2, CALM3 and TNNI3K polymorphisms as potential disease modifiers in hypertrophic and dilated cardiomyopathies.

In the original publication of the article, the location and rs number of TNNI3K mouse SNP (3784 C>T) (rs49812611) has been mentioned inadvertently in place of its human homologue. The correct information for human SNP is rs760769780 located at position 74436534, resulting in (G>A) change in human TNNI3K gene.

ACE2, CALM3 and TNNI3K polymorphisms as potential disease modifiers in hypertrophic and dilated cardiomyopathies.

The marked clinical and genetic heterogeneity seen in hypertrophic (HCM) and dilated cardiomyopathies (DCM) suggests involvement of disease modifiers and environmental factors in the pathophysiology of these diseases. In the current study, we examined association of single nucleotide polymorphisms (SNPs) of three candidate genes, ACE2 (rs6632677), TNNI3K (rs49812611) and CALM3 (rs13477425) with clinical phenotypes of HCM and DCM patients of North Indian ethnicity. Prevalence of ACE2 (7160726 C>G) variant genotypes (CG and GG) was significantly higher in DCM subjects as compared to controls. Prevalence of TNNI3K (3784 C>T) and CALM3 (-34T>A) variant homozygous genotype were significantly higher in HCM and DCM subjects as compared to controls. DCM patients with CT genotype showed significant decrease in LVEF as compared to CC genotype (p < 0.03). There was significant gene-gene interaction between these SNPs and three-way SNP combination of ACE2 C>G, TNN13K C>T, CALM3 A>T gene variants and was associated with high risk of HCM and DCM. Presence of ACE2 (7160726 C>G) and CALM3 (-34T>A) variant genotypes in HCM Patients with mutations (sarcomeric or non sarcomeric genes) was associated with increased mean septal thickness, further suggesting a role of these gene variants in modifying disease phenotype. Our results suggest that ACE2, TNNI3K and CALM3 polymorphisms are associated with increased risk of HCM and DCM and may act as disease modifiers of these diseases.

Renin-angiotensin system gene polymorphisms as potential modifiers of hypertrophic and dilated cardiomyopathy phenotypes.

The renin-angiotensin (RAS) pathway has an important role in the etiology of heart failure and given the importance of RAS as a therapeutic target in various cardiomyopathies, genetic polymorphisms in the RAS genes may modulate the risk and severity of disease in cardiomyopathy patients. In the present study, we examined the association of RAS pathway gene polymorphisms, angiotensin converting enzyme (ACE), angiotensinogen (AGT), and angiotensin receptor type 1 (AGTR1) with risk and disease severity in Asian Indian idiopathic cardiomyopathy patients. The case-control study was conducted in 400 cardiomyopathy patients diagnosed with HCM, DCM, or restrictive cardiomyopathy (RCM) and 235 healthy controls. Genotyping of patients and controls was done by PCR-RFLP assays. Left ventricular wall thickness and left ventricular ejection fraction were measured by means of M-mode echocardiography. We observed significantly higher prevalence of ACE DD and AGTR1 1166CC genotypes in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) patients. Also, 235TT genotype of AGT (M235T) was significantly associated with enhanced risk of the disease phenotype in HCM, DCM, and RCM.

MicroRNA-200c modulates DUSP-1 expression in diabetes-induced cardiac hypertrophy.

Mitogen-activated protein kinases (MAPKs) (ERK1/2, JNK, and p38) are upregulated in diabetic cardiomyopathy (DCM). Dual-specific phosphatase-1 (DUSP-1) has been reported to regulate the activity of MAPKs in cardiac hypertrophy; however, the role of DUSP-1 in regulating MAPKs activity in DCM is not known. MicroRNAs have been reported to regulate the expression of several genes in hypertrophied failing hearts. However, little is known about the microRNAs regulating DUSP-1 expression in diabetes-related cardiac hypertrophy. In the present study, we investigated the role of DUSP-1 and miR-200c in diabetes-induced cardiac hypertrophy. DCM was induced in Wistar rats by low-dose Streptozotocin high-fat diet for 12 weeks. Cardiac expression of ERK, p-38, JNK, DUSP-1, miR-200c, and hypertrophy markers (ANP and ß-MHC) was studied in DCM in control rats and in high-glucose (HG)-treated rat neonatal cardiomyocytes. miR-200c inhibition was performed to validate DUSP-1 as target. A significant increase in phosphorylated ERK, p38, and JNK was observed in DCM model and in HG-treated cardiomyocytes (p < 0.05). Expression of DUSP-1 was significantly decreased in diabetes group and in HG-treated cardiomyocytes (p < 0.05). Increased expression of miR-200c was observed in DCM model and in HG-treated cardiomyocytes (p < 0.05). Inhibition of miR-200c induces the expression of the DUSP-1 causing decreased expression of phosphorylated ERK, p38, and JNK and attenuated cardiomyocyte hypertrophy in HG-treated cardiomyocytes. miR-200c plays a role in diabetes-associated cardiac hypertrophy by modulating expression of DUSP-1.

miR-30c and miR-181a synergistically modulate p53-p21 pathway in diabetes induced cardiac hypertrophy.

p53-p21 pathway mediates cardiomyocyte hypertrophy and apoptosis and is upregulated in diabetic cardiomyopathy (DbCM). We investigated role of microRNAs in regulating p53-p21 pathway in high glucose (HG)-induced cardiomyocyte hypertrophy and apoptosis. miR-30c and miR-181a were identified to target p53. Cardiac expression of microRNAs was measured in diabetic patients, diabetic rats, and in HG-treated cardiomyocytes. Effect of microRNAs over-expression and inhibition on HG-induced cardiomyocyte hypertrophy and apoptosis was examined. Myocardial expression of p53 and p21 genes was increased and expression of miR-30c and miR-181a was significantly decreased in diabetic patients, DbCM rats, and in HG-treated cardiomyocytes. Luciferase assay confirmed p53 as target of miR-30c and miR-181a. Over-expression of miR-30c or miR-181a decreased expression of p53, p21, ANP, cardiomyocyte cell size, and apoptosis in HG-treated cardiomyocytes. Concurrent over-expression of these microRNAs resulted in greater decrease in cardiomyocyte hypertrophy and apoptosis, suggesting a synergistic effect of these microRNAs. Our results suggest that dysregulation of miR-30c and miR-181a may be involved in upregulation of p53-p21 pathway in DbCM.

Role of cardiac TBX20 in dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is an important cause of heart failure and sudden cardiac death worldwide. Transcription factor TBX20 has been shown to play a crucial role in cardiac development and maintenance of adult mouse heart. Recent studies suggest that TBX20 may have a role in pathophysiology of DCM. In the present study, we examined TBX20 expression in idiopathic DCM patients and in an animal model of cardiomyopathy, and studied its correlation with echocardiographic indices of LV function. Endomyocardial biopsies (EMBs) from intraventricular septal from the right ventricle region were obtained from idiopathic DCM patients (IDCM, n = 30) and from patients with ventricular septal defect (VSD, n = 14) with normal LVEF who served as controls. An animal model of DCM was developed by right renal artery ligation in Wistar rats. Cardiac TBX20 mRNA levels were measured by real-time PCR in IDCM, controls, and in rats. The role of DNA promoter methylation and copy number variation (CNVs) in regulating TBX20 gene expression was also investigated. Cardiac TBX20 mRNA levels were significantly increased (8.9 fold, p < 0.001) in IDCM patients and in RAL rats as compared to the control group. Cardiac TBX20 expression showed a negative correlation with LVEF (r = -0.71, p < 0.001) and a positive correlation with left ventricular end-systolic volume (r = 0.39, p = 0.038). No significant difference in TBX20 CNVs and promoter methylation was observed between IDCM patients and control group. Our results suggest a potential role of TBX20 in pathophysiology of DCM.