Huan-Chun Ni

HLA-DR4 antigen and idiopathic dilated cardiomyopathy susceptibility: a meta-analysis involving 11,761 subjects.

Idiopathic dilated cardiomyopathy (IDC) has been hypothesized as a multifactorial disorder initiated by an environment trigger in individuals with predisposing human leukocyte antigen (HLA) alleles. Published data on the association between HLA-DR4 antigen and IDC risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Studies in English-language articles were identified by a search of PubMed and Embase database (inception to June 2010). A total of 19 case-control studies including 1378 cases and 10,383 controls provided data on the association between HLA-DR4 antigen and genetic susceptibility to IDC. Overall, statistically elevated frequency of HLA-DR4 allele [OR (odds ratio), 1.58; 95% CI (confidence interval), 1.21-2.07; P = 0.0009] was found in patients with IDC compared with controls. When stratified by myocardial biopsy or non-biopsy cases, statistically increased risks were found for IDC in both subgroups. In the subgroup analysis by ethnicity, significantly increased risk was found among Europeans from 12 case-control studies (OR, 1.54; 95% CI, 1.11-2.12; P = 0.009). In conclusion, our results suggest that HLA-DR4 antigen is a low-penetrant risk factor for developing IDC in Europeans.

Cardiac matrix remodeling following intracoronary cell transplantation in dilated cardiomyopathic rabbits

Cellular cardiomyoplasty has been proposed as a promising therapeutic strategy for chronic heart failure. Previous studies focused on structural changes in cardiomyocytes to explain the potential benefits for contractile function. However, limited information is available about the cardiac matrix remodeling following cell transplantation in dilated cardiomyopathy (DCM). Here, we established a new animal model of intracoronary bone marrow mononuclear cells (BMMNCs) transplantation to explore extracellular matrix remodeling in adriamycin-induced cardiomyopathic rabbits. In vivo studies demonstrated that BMMNCs transplantation can dramatically delay the progress of collagen metabolism and decrease myocardial collagen volume fraction. The beneficial effects were mediated by attenuating stress-generated over-expression of matrix metalloproteinases (MMPs) in ventricular remodeling. Improved cardiac function may be contributed in part by stem-associated inhibition of extracellular matrix remodeling.

Phosphodiesterase type 5 inhibitors for high-altitude pulmonary hypertension: a meta-analysis.

AbstractBackground: High-altitude pulmonary hypertension (HAPH) is a public health problem in mountainous areas of the world. Treatment options for this condition are unsatisfactory. Recent interest in use of selective phosphodiesterase type 5 (PDE5) inhibitors for pulmonary hypertension has suggested a possible role for these agents in the treatment of HAPH. Preliminary data from several small studies have shown beneficial haemodynamic effects of empirical PDE5 treatment of HAPH but the results of these studies have been challenged. Objective: We performed a meta-analysis to explore the potential therapeutic effects of PDE5 inhibitors for HAPH. p ]Methods: Randomized controlled trials were identified to test the effects of PDE5 inhibitors in HAPH by searching PubMed (inception to June 2009). A standardized protocol with predefined criteria was used to extract details on study design, Jadad score, demographic data, interventions and outcomes. The main outcomes assessed were cardiopulmonary parameters. Treatment effects for continuous variables were presented as weighted mean differences with 95% confidence intervals. Results: Ten clinical trials were identified and included for the meta-analysis. The weighted mean difference in systolic pulmonary artery pressure post-treatment at rest in PDE5 inhibitor-treated subjects was −7.51 mmHg (95% CI −10.87, −4.16; p <0.0001) compared with controls, whereas the analysis of systolic blood pressure and heart rate demonstrated that no significant effects were observed in the active treatment group at rest and during exercise. Conclusions: The available evidence suggests PDE5 inhibitors can attenuate altitude-induced pulmonary hypertension without significantly affecting systemic blood pressure or heart rate.

The Impact of Circulating Mitochondrial DNA on Cardiomyocyte Apoptosis and Myocardial Injury After TLR4 Activation in Experimental Autoimmune Myocarditis

Background/Aims: Mitochondrial DNA (mtDNA), acting as a newly found ‘danger-associated molecular patterns’ (DAMPs), is released into circulation upon tissue injury and performs as a considerable activator of inflammation and immune response. However, the role of circulating mtDNA in experimental autoimmune myocarditis (EAM) as well as Toll like receptor4 (TLR4) mediated cardiac inflammation and injury remains unknown. Methods: A model of EAM was established in BALB/c mice by immunization with porcine cardiac myosin. Lipopolysaccharide (LPS) was used to stimulate TLR4 activation in EAM mice and H9C2 cells. Results: LPS stimulation significantly aggravated cardiac inflammation and tissue injury in EAM, as demonstrated by increased myocardium inflammatory cell infiltration, and up-regulated inflammatory cytokines and troponin I(TnI) level in serum. Circulating mtDNA level was increased in EAM and TLR4 activation led to a greater elevation, which may be related to Reactive oxygen species (ROS) stress involved mtDNA damage characterized by reduced mtDNA copy number in myocardium tissue. In addition, the expression of Toll like receptor9 (TLR9), a ligand of mtDNA, was significantly up-regulated in the myocardium of EAM and EAM LPS group; meanwhile, TLR9 inhibition by ODN 2088 caused an inhibited apoptosis in LPS treated H9C2 cells. Moreover, in EAM and EAM LPS group, simultaneously giving ODN 2088 treatment significantly ameliorated cardiac inflammation and tissue injury compared with untreated group. Conclusion: Increased circulating mtDNA combined with upregulated TLR9 expression may corporately play a role in EAM as well as TLR4 activation mediated cardiac inflammation and injury.

Tissue Factor Pathway Inhibitor-2 Gene Polymorphisms Associate With Coronary Atherosclerosis in Chinese Population.

Abstract Tissue factor pathway inhibitor-2 (TFPI-2) may play critical roles in the pathogenesis of atherosclerosis. In this study, we aimed to investigate the association between TFPI-2 gene polymorphisms and coronary atherosclerosis. Four hundred and seven patients with coronary atherosclerosis and 306 individuals with normal coronary artery were enrolled in the present study. Nine single-nucleotide polymorphisms (SNPs) (rs3763473, rs59805398, rs60215632, rs59999573, rs59740167, rs34489123, rs4517, rs4264, and rs4271) were detected with polymerase chain reaction-direct sequencing method. Severity of coronary atherosclerosis was assessed by Gensini score. After the baseline investigation, patients with coronary atherosclerosis were followed up for incidence of cardiovascular events (CVEs). Eight SNPs were in accordance with the Hardy–Weinberg equilibrium, and 8 haplotypes were constructed based on rs59999573, rs59740167, and rs34489123 after linkage disequilibrium and haplotype analysis. Two SNPs (rs59805398 and rs34489123) and 5 haplotypes correlated with coronary atherosclerosis even after adjustment by Gensini score. At follow-up (median 53 months, range 1–60 months), 85 patients experienced CVE. However, there was no strong association between the gene polymorphisms and the occurrence of CVE. Tissue factor pathway inhibitor-2 gene polymorphisms were associated with coronary atherosclerosis in the Chinese population, suggesting that the information about TFPI-2 gene polymorphisms was useful for assessing the risk of developing coronary atherosclerosis, but there was not enough evidence showing it could predict occurrence of CVE.

Cardiac arrhythmias as the initial manifestation of adult primary Sjögren's syndrome: a case report and literature review.

Two middle‐aged female patients presenting with heart palpitation and electrocardiogram revealed complex cardiac arrhythmias. A review of systems was positive for dry mouth and transient arthralgia, while laboratory and instrumental tests enabled us to make the diagnosis of primary Sjögrens syndrome (pSS). Cardiac electrophysiology revealed atrioventricular node dysfunction and impaired intraventricular conduction. Prednisone therapy induced a significant improvement in symptoms and electrocardiographic readings. The diagnosis of pSS should be considered in a patient presenting with complex cardiac arrhythmias.

High levels of LDL-C combined with low levels of HDL-C further increase platelet activation in hypercholesterolemic patients

High levels of low-density lipoprotein cholesterol (LDL-C) enhance platelet activation, whereas high levels of high-density lipoprotein cholesterol (HDL-C) exert a cardioprotective effect. However, the effects on platelet activation of high levels of LDL-C combined with low levels of HDL-C (HLC) have not yet been reported. We aimed to evaluate the platelet activation marker of HLC patients and investigate the antiplatelet effect of atorvastatin on this population. Forty-eight patients with high levels of LDL-C were enrolled. Among these, 23 had HLC and the other 25 had high levels of LDL-C combined with normal levels of HDL-C (HNC). A total of 35 normocholesterolemic (NOMC) volunteers were included as controls. Whole blood flow cytometry and platelet aggregation measurements were performed on all participants to detect the following platelet activation markers: CD62p (P-selectin), PAC-1 (GPIIb/IIIa), and maximal platelet aggregation (MPAG). A daily dose of 20 mg atorvastatin was administered to patients with high levels of LDL-C, and the above assessments were obtained at baseline and after 1 and 2 months of treatment. The expression of platelets CD62p and PAC-1 was increased in HNC patients compared to NOMC volunteers (P<0.01 and P<0.05). Furthermore, the surface expression of platelets CD62p and PAC-1 was greater among HLC patients than among HNC patients (P<0.01 and P<0.05). Although the expression of CD62p and PAC-1 decreased significantly after atorvastatin treatment, it remained higher in the HLC group than in the HNC group (P<0.05 and P=0.116). The reduction of HDL-C further increased platelet activation in patients with high levels of LDL-C. Platelet activation remained higher among HLC patients regardless of atorvastatin treatment.

TLR4 Activation Promotes the Progression of Experimental Autoimmune Myocarditis to Dilated Cardiomyopathy by Inducing Mitochondrial Dynamic Imbalance

Mitochondrial dynamic imbalance associates with several cardiovascular diseases. However, the role of mitochondrial dynamics in TLR4 activation-mediated dilated cardiomyopathy (DCM) progress remains unknown. A model of experimental autoimmune myocarditis (EAM) was established in BALB/c mice on which TLR4 activation by LPS-EB or TLR4 inhibition by LPS-RS was performed to induce chronic inflammation for 5 weeks. TLR4 activation promoted the transition of EAM to DCM as demonstrated by increased cardiomyocyte apoptosis, myocardial fibrosis, ventricular dilatation, and declined heart function. TLR4 inhibition mitigated the above DCM changes. Transmission electron microscope study showed that mitochondria became fragmented, also with damaged crista in ultrastructure in EAM mice. TLR4 activation aggravated the above mitochondrial aberration, and TLR4 inhibition alleviated it. The mitochondrial dynamic imbalance and damage in DCM development were mainly associated with OPA1 downregulation, which may be caused by elevated TNF-α level and ROS stress after TLR4 activation. Furthermore, OMA1/YME1L abnormal degradation was involved in the OPA1 dysfunction, and intervening OMA1/YME1L in H9C2 significantly alleviated mitochondrial fission, ultrastructure damage, and cell apoptosis induced by TNF-α and ROS. These data indicate that TLR4 activation resulted in OPA1 dysfunction, promoting mitochondrial dynamic imbalance and damage, which may involve in the progress of EAM to DCM.

Tenascin C: A Potential Biomarker for Predicting the Severity of Coronary Atherosclerosis

Aims: Coronary artery disease (CAD) is the leading cause of mortality and morbidity worldwide and one of the greatest threats to public health. Tenascin C (TNC) is an extracellular matrix glycoprotein that is found in low concentrations in normal tissues and is enhanced by a range of cardiovascular pathologies. This study aimed to evaluate the value of TNC in assessing the severity of atherosclerosis measured by the Gensini score. Methods: A total of 157 patients with chest pains who underwent selective coronary angiography for suspected coronary atherosclerosis were enrolled. The patients were divided into the CAD group and non-CAD group according to symptoms and angiography. Demographic data and laboratory analyses were collected. Results: The mean TNC level was significantly higher in the CAD group than in the non-CAD group (p < 0.001). A significant positive correlation between TNC levels and Gensini score (p < 0.01, r = 0.672) was found. ROC curve analysis demonstrated that the cutoff value for TNC at 89.48 ng/mL was well differentiated in the CAD and non-CAD groups. Furthermore, TNC was also a good predictor for a higher Gensini score (the third tertile) in the ROC curve analysis. When the cutoff was accepted as 100.91 ng/mL, the sensitivity and specificity were 82.7% and 79%, respectively. Conclusion: A significant relationship was found between the Gensini score and serum TNC level. TNC levels can be considered in risk assessments for CAD before angiography.