Association of the MicroRNA-146a SNP rs2910164 with Ischemic Stroke Incidence and Prognosis in a Chinese Population.

We conducted a case-control study investigating the association between the single-nucleotide polymorphism rs2910164 in microRNA (miR)-146a and the risk and prognosis of stroke. We recruited a total of 1139 ischemic stroke patients and 1585 sex- and age-matched control subjects. After a median follow-up period of 4.5 years, 1071 of these ischemic stroke patients were then recruited for a prospective study. Our study revealed that rs2910164 was not associated with ischemic stroke incidence (odds ratio = 1.00; 95% confidence interval (CI) = 0.80-1.24; p = 0.985) by multivariate logistic regression. Meta-analysis of our case-control study and three others on Asian populations also suggested that there was no relationship between rs2910164 and ischemic stroke incidence. The significance of differences in long-term outcomes was examined by the log-rank test of the respective comparison groups. The prospective study showed that rs2910164 led to a 1.56-fold increased risk of stroke recurrence (hazard ratio (HR) = 1.56; 95% CI = 1.10-2.20; p = 0.013) and a 2.13-fold increased risk of death caused by cardiovascular disease or stroke (Csdeath) (HR = 2.13; 95% CI = 1.31-3.46; p = 0.002). The independent association of rs2910164 with stroke prognosis was evaluated using Cox regression models. Therefore, rs2910164 appears to be a strong predictor of stroke prognosis but not of stroke incidence in Asian populations.

A functional variant in the coding region of CAMTA2 is associated with left ventricular hypertrophy by affecting the activation of Nkx2.5-dependent transcription.

OBJECTIVE: The calmodulin-binding transcription activator 2 (CAMTA2) promotes transcription of genes involved in cardiac hypertrophy through its interaction with Nkx2.5 and is an indispensable transcription coactivator for cardiac hypertrophy. We hypothesized that variants in the coding region of CAMTA2 would affect its function and confer a risk of cardiac hypertrophy. METHODS: The effects of the variant rs238234 on the activity of the atrial natriuretic factor promoter and on the cardiomyocytes hypertrophy were assessed in the H9C2 cell line and primary neonatal rat cardiomyocytes, respectively. Furthermore, the association of this variant with left ventricular hypertrophy (LVH) was tested in hypertensive patients with and without hypertrophy (N = 325 and 697), and this analysis was replicated in an independent population of 987 hypertensive patients without hypertrophy and 463 hypertensive patients with hypertrophy. RESULTS: We found that the G allele of rs238234 activated the atrial natriuretic factor promoter more strongly than the C allele. The cell size of cardiomyocytes was larger in the presence of the Ad-CAMTA2 G allele, and the G allele was associated with significantly increased susceptibility to LVH in hypertensive [odds ratio (OR), 1.29; P = 0.009]. In the discovery cohort, after adjusting for age and sex, the GG genotype was significantly associated with increased LVH risk (OR, 1.75; P = 0.015). There was little attenuation of the ORs (1.62; P < 0.05) when adjusting for BMI, heart rate, blood pressure, smoking, and drinking and further adjusting all covariates including lipid levels and other major risk factors. However, the GC genotype did not show any association with LVH using three regressive models. Replication in the second study yielded similar results. CONCLUSION: Our results provide evidence that the rs238234 GG genotype in the coding region of CAMTA2 may increase the risk of LVH by affecting the activation of Nkx2.5-dependent transcription.

Plasma concentrations of interleukin-6, C-reactive protein, tumor necrosis factor-α and matrix metalloproteinase-9 in aortic dissection.

BACKGROUND: The role of inflammation in aortic dissection (AD) has not fully been investigated. We evaluated the potential relationships between interleukin-6 (IL-6), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and matrix metalloproteinase-9 (MMP-9) and AD. METHODS: Plasma concentrations of IL-6, TNF-α, MMP-9 and CRP were determined in 64 acute AD patients, 42 patients with chronic AD, 98 patients with hypertension alone, and 96 healthy subjects. RESULTS: IL-6 concentrations were higher in acute AD than that in hypertension and healthy controls (10.98±2.38 vs. 3.79±1.56 and 3.32±1.60 pg/ml, P<0.05, respectively). Increased CRP concentrations were found in acute AD compared with chronic AD and hypertension as well as healthy subjects (13.48±3.74 vs. 4.12±2.99, 1.62±0.65 and 1.12±0.35 mg/l, P<0.001, respectively). Higher MMP-9 concentrations were detected in acute AD, chronic AD and hypertension compared with healthy controls (37.75±9.38, 55.78±6.41 and 31.03±7.94 vs. 21.24±7.28 ng/ml, P<0.05, P<0.001 and P<0.05, respectively), and in the dead compared to the survived (107.29±9.38 vs. 86.80±7.93 ng/ml, P<0.001) among acute AD patients. In acute AD, the time after onset had positive correlation with TNF-α (r=0.497, P=0.000), and negative correlation with CRP (r=-0.424, P=0.000). Plasma CRP levels decreased significantly when the onset time increased (P=0.013). Moreover, in the patients with acute AD who underwent surgery and stenting, plasma MMP-9 concentrations increased immediately after surgical treatment and stenting, and reached the peak values at 24h, then decreased at 1 week (P<0.001). CONCLUSIONS: Our findings confirmed and extended previous studies that increased plasma inflammatory markers were significantly associated with AD.

Protective effect of chrysoeriol against doxorubicin-induced cardiotoxicity in vitro.

BACKGROUND: The use of doxorubicin (DOX) is limited by its dose-dependent cardiotoxicity. Reactive oxygen species (ROSs) play an important role in the pathological process of DOX-induced cardiotoxicity. The aim of this study was to evaluate the protective effect of chrysoeriol, a flavone compound, against DOX-induced apoptosis and death in H9c2 cells and to find out its preliminary mechanism. METHODS: We used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, Hoechst33258 staining and measurement of lactate dehydrogenase (LDH) release to evaluate the protective effect of chrysoeriol against DOX-induced apoptosis and death in H9c2 cells. To find out the mechanism of this protective effect, we observed the immunofluorescence of intracellular ROS and measured the activities of malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPx). Furthermore, we evaluated the effect of chrysoeriol on the antitumor activity of DOX in HeLa cells with MTT assay. RESULTS: The results of MTT assay, Hoechst 33258 staining and measurement of LDH release showed that chrysoeriol significantly reduced doxorubicin-induced apoptosis and cell death. Chrysoeriol at a dose of 20 microg/ml notably reduced intracellular ROS, decreased the concentration of MDA in the supernatant of DOX-treated H9c2 cells and increased SOD and GPx activities to their normal levels. Further study showed that the addition of chrysoeriol did not affect the antitumor activity of DOX. CONCLUSION: Chrysoeriol could potentially serve as a novel cardioprotective agent against DOX-induced cardiotoxicity without affecting the antitumor activity of DOX.

[The genotype-phenotype correlation of the MYH7 gene c.1273G > a mutation in familial hypertrophic cardiomyopathy].

To investigate the genotype-phenotype correlation in Chinese familial hypertrophic cardiomyopathy (HCM), peripheral blood samples were collected from 7 members of a Chinese HCM family, and 120 normal subjects were recruited as control. The full encoding exons and flanking sequences of the cardiac troponin T (TNNT2) gene, beta-myosin heavy chain (MYH7) gene and myosin binding protein C (MYBPC3) gene were amplified and the products were sequenced directly to detect the mutations. A missense mutation, c.1273G>A, was identified in exon 14 of the MYH7 gene in 4 members of the Chinese HCM family, which resulted a glycine (Gly) to arginine (Arg) exchange at amino acid residue 425. The 425th glycine amino acid residue is highly conservative across the different species. The clinical phenotypes among the family members who carried this mutation presented significant individual differences. The c.1273G>A mutation of the MYH7 gene might be the causal mutation of the familial HCM. The heterogeneity of phenotypes suggested that multiple factors may be involved in the pathogenesis of HCM.

[A novel hot-spot mutation S236G in the cardiac myosin binding protein C gene in Chinese patient with hypertrophic cardiomyopathy].

OBJECTIVE: To identify the disease-causing gene mutations and to reveal the relationship between the genotype and the phenotype in Chinese patients with hypertrophic cardiomyopathy (HCM). METHODS: One hundred unrelated patients with HCM and 120 controls were enrolled in this study. The full encoding exons and flanking sequences of the cardiac myosin binding protein C gene (MYBPC3) were amplified with PCR and the products were sequenced. RESULTS: A novel missense mutation c.706T > C was identified in exon 6 of MYBPC3 gene in three HCM patients, which resulted a Serine (S) to Glycine (G) exchange at amino acid residue 236 (S236G). The clinical phenotypes of the three patients were different (2 obstructive HCM, 1 non-obstructive HCM). The 120 controls were normal in the genetic test. CONCLUSIONS: The novel S236G mutation in MYBPC3 gene was a hot-spot mutation in Chinese patients with HCM.

[Genetic heterogeneity of myosin heavy chain 7 gene G823E mutation in familial hypertrophic cardiomyopathy in Chinese].

OBJECTIVE: To study the disease-causing gene mutations in familial hypertrophic cardiomyopathy (HCM) in Chinese and to reveal the relationship between the genotype and the phenotype. METHODS: Peripheral blood samples were collected from 12 members of a HCM family, and 120 healthy volunteers in China. PCR and double deoxygenation chain termination method were used to analyze the cardiac troponin T gene (TNNT2), beta-myosin heavy chain gene (MYH7) gene and myosin binding protein C gene (MYBPC3) and to detect mutations. RESULTS: Mutation G14452A was identified in exon 22 of MYH7 gene in 4 family members, causing the conversion of glycine (G) into glutamic acid (E). The onset ages and clinical manifestations of the family members carrying the mutation G823E, including 2 patients (the proband, male, with the onset age of 51, and his 26-year-old second son with the onset age of 20), and 2 carriers (his 31-year-old elder son and 29-year-old elder daughter), presented significant individual differences. CONCLUSIONS: The G823E mutation of MYH7 gene is the causal mutation of familial HCM. The heterogeneity of phenotypes suggests that multiple factors may be involved in the pathogenesis of HCM.

[The genotype-phenotype correlation of MYH7 gene G15391A mutation and MYBPC3 gene G12101A mutation in familial hypertrophic cardiomyopathy].

OBJECTIVE: To reveal genotype-phenotype correlation of disease-causing gene mutations in Chinese hypertrophic cardiomyopathy (HCM) pedigree. METHODS: Peripheral venous blood samples were collected from two Chinese HCM families and 120 healthy subjects were recruited as normal control. The full encoding exons and flanking sequences of the cardiac troponin T gene (TNNT2), beta-myosin heavy chain gene (MYH7) and myosin binding protein C gene (MYBPC3) were amplified with the polymerase chain reaction method, DNA sequencing was used to detect the mutation. RESULTS: In ZZJ family, mutation G12101A was identified in exon 21 of MYBPC3 gene in 4 family members [the arginine (R) converted to histidine (H)]. In this pedigree, three out of eight family members were diagnosed as HCM and with a penetrance of 75%. In FHL family, mutation G15391A was identified in exon 23 of MYH7 gene in 3 family members [the glutamic acid (E) converted to lysine (K)]. In this pedigree, three out of six family members were diagnosed as HCM and with a penetrance of 100%. Echocardiography showed obstruction of left ventricular outflow tract in two out of the three HCM patients. CONCLUSIONS: Our results showed that the G12101A mutation of MYBPC3 gene is the causal mutation of familial HCM with mild phenotype. The G15391A mutation of MYH7 gene is the causal mutation of familial HCM with malignant phenotype and a penetrance of 100%. Screening mutations in the MYH7 gene should be viewed as a reasonable procedure in obstructive HCM patients.

Epigallocathechin-3 gallate inhibits cardiac hypertrophy through blocking reactive oxidative species-dependent and -independent signal pathways.

Cardiac hypertrophy is a major cause of morbidity and mortality worldwide. Recent in vitro and in vivo studies have suggested that reactive oxygen species (ROS) may play an important role in cardiac hypertrophy. It was therefore thought to be of particular value to examine the effects of antioxidants on cardiac hypertrophy. Epigallocatechin-3-gallate (EGCG) is a major bioactive polyphenol present in green tea and a potent antioxidant. The current study was designed to test the hypothesis that EGCG inhibits cardiac hypertrophy in vitro and in vivo. In this study, we investigated the effects of EGCG on angiotensin II- (Ang II) and pressure-overload-induced cardiac hypertrophy. Our results showed that EGCG attenuated Ang II- and pressure-overload-mediated cardiac hypertrophy. Both reactive oxygen species generation and NADPH oxidase expressions induced by Ang II and pressure overload were suppressed by EGCG. The increased hypertension by pressure overload was almost completely blocked after EGCG treatment. Further studies showed that EGCG inhibited Ang II-induced NF-kappaB and AP-1 activation. Inhibition of the activity of NF-kappaB was through blocking ROS-dependent p38 and JNK signaling pathways, whereas inhibition of AP-1 activation was via blocking EGFR transactivation and its downstream events ERKs/PI3K/Akt/mTOR/p70(S6K). The combination of these actions resulted in repressing the reactivation of ANP and BNP, and ultimately preventing the progress of cardiac hypertrophy. These findings indicated that EGCG prevents the development of cardiac hypertrophy through ROS-dependent and -independent mechanisms involving inhibition of different intracellular signaling transductional pathways.

Isorhapontigenin, a new resveratrol analog, attenuates cardiac hypertrophy via blocking signaling transduction pathways.

Cardiac hypertrophy is a major cause of morbidity and mortality worldwide. The hypertrophic process is mediated, in part, by oxidative stress-mediated signaling pathways. We hypothesized that isorhapontigenin (ISO), a new resveratrol analog, inhibits cardiac hypertrophy by blocking oxidative stress and oxidative stress-mediated signaling pathways. We treated cardiomyocytes with angiotensin II (Ang II) with or without ISO and found that ISO inhibited Ang II-induced cardiac hypertrophy. These effects were associated with a decrease in the levels of reactive oxygen species and H2O2 and the content of intracellular malonaldehyde and an increase in the activities of superoxide dismutase and glutathione peroxidase. Ang II induced the phosphorylation of PKC, Erk1/2, JNK, and p38 in cardiomyocytes and such phosphorylation was inhibited by ISO. ISO also blocked the PKC-dependent PI3K-Akt-GSK3beta/p70S6K pathway. These effects lead to direct or indirect inhibition of NF-kappaB and AP-1 activation. Our results revealed that pretreatment with ISO significantly inhibited Ang II-mediated NF-kappaB through affecting the degradation and phosphorylation of IkappaBalpha and the activity of IKKbeta and AP-1 activation by influencing the expression of c-Fos and c-Jun proteins. In addition, we also established the molecular link between activation of PKC and MAPKs and activation of NF-kappaB and AP-1 in cardiomyocytes. We also found that ISO treatment significantly attenuated heart weight/body weight ratio by approximately 25%, decreased posterior wall thickness and left ventricle diastolic and systolic diameters, and increased 10% fractional shortening in an aortic-banded rat model. Furthermore, treatment with ISO significantly decreased cardiac myocyte size and systolic blood pressure. These findings suggest that ISO prevents the development of cardiac hypertrophy through an antioxidant mechanism involving inhibition of different intracellular signaling transduction pathways.