Jinfa Jiang

Circulating miR-21, miR-378, and miR-940 increase in response to an acute exhaustive exercise in chronic heart failure patients.

Congestive heart failure (CHF) is a major cause of hospitalizations, morbidity, and mortality in Western societies. In addition to optimal medical and device therapy, exercise training is an important adjunct treatment option for CHF patients. MicroRNAs (miRNAs, miRs) participate in a variety of physiological and pathological processes. Dynamic regulation of circulating miRNAs during exercise in healthy persons and athletes has recently been documented, however, the response of circulating miRNAs to exercise in CHF patients is undetermined. Twenty-eight CHF patients underwent a symptom-limited incremental cardiopulmonary exercise test on a bicycle ergometer using a standardized exercise protocol of revised Ramp10 programs at Shanghai Tongji Hospital. Blood samples were collected before and immediately after an acute exercise session. RNA was extracted from the serum and selected miRNAs were determined using quantitative polymerase chain reactions. Moreover, inflammatory and muscle damage markers were determined by enzyme linked immunosorbent assays. We found that serum miR-21, miR-378 and miR-940 levels were significantly up-regulated immediately following an acute exercise while the rest were not changed. In addition, no robust correlation was identified between changes of these miRNAs and exercise capacity, muscle damage or inflammation. In conclusion, serum miR-21, miR-378, and miR-940 increase in response to an acute exhaustive exercise in CHF patients. Further studies are needed to clarify the potential use of circulating miRNAs as biomarkers of exercise adaptation in CHF patients, and if they have any use as prognostic markers of cardiovascular outcomes.

A novel GATA4 loss-of-function mutation responsible for familial dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is the most common form of primary myocardial disorder and is associated with substantial morbidity and mortality. Increasing evidence suggests that genetic risk factors play an important role in the pathogenesis of idiopathic DCM. However, DCM is a genetically heterogeneous disease, and the genetic defects responsible for DCM in an overwhelming majority of cases remain to be identified. In the present study, the entire coding region and the splice junction sites of the GATA4 gene, which encodes a cardiac transcription factor essential for cardiogenesis, were sequenced in 150 unrelated patients with idiopathic DCM. The available relatives of the index patient harboring an identified mutation and 200 unrelated ethnically matched healthy individuals used as controls were genotyped. The functional characteristics of the mutant GATA4 were delineated in contrast to its wild-type counterpart using a luciferase reporter assay system. As a result, a novel heterozygous GATA4 mutation, p.V291L, was identified in a family with DCM inherited in an autosomal dominant pattern, which co-segregated with DCM in the family with complete penetrance. The missense mutation was absent in 400 control chromosomes, and the altered amino acid was completely conserved evolutionarily among species. Functional analysis revealed that the GATA4 mutant was associated with significantly diminished transcriptional activity. The findings expand the mutational spectrum of GATA4 linked to DCM and provide novel insight into the molecular etiology involved in DCM, suggesting the potential implications in the early prophylaxis and allele-specific treatment for this common type of cardiomyopathy.

HAND1 loss-of-function mutation associated with familial dilated cardiomyopathy

Abstract Background: The basic helix-loop-helix transcription factor HAND1 is essential for cardiac development and structural remodeling, and mutations in HAND1 have been causally linked to various congenital heart diseases. However, whether genetically compromised HAND1 predisposes to dilated cardiomyopathy (DCM) in humans remains unknown. Methods: The whole coding region and splicing junctions of the HAND1 gene were sequenced in 140 unrelated patients with idiopathic DCM. The available family members of the index patient carrying an identified mutation and 260 unrelated ethnically matched healthy individuals used as controls were genotyped for HAND1. The functional effect of the mutant HAND1 was characterized in contrast to its wild-type counterpart by using a dual-luciferase reporter assay system. Results: A novel heterozygous HAND1 mutation, p.R105X, was identified in a family with DCM transmitted as an autosomal dominant trait, which co-segregated with DCM in the family with complete penetrance. The nonsense mutation was absent in 520 control chromosomes. Functional analyses unveiled that the mutant HAND1 had no transcriptional activity. Furthermore, the mutation abolished the synergistic activation between HAND1 and GATA4, another crucial cardiac transcription factors that has been associated with various congenital cardiovascular malformations and DCM. Conclusions: This study firstly reports the association of HAND1 loss-of-function mutation with increased susceptibility to DCM in humans, which provides novel insight into the molecular mechanisms underpinning DCM.

Mutational spectrum of the NKX2-5 gene in patients with lone atrial fibrillation.

Atrial fibrillation (AF) is the most common form of sustained cardiac arrhythmia in humans and is responsible for substantial morbidity and mortality worldwide. Emerging evidence indicates that abnormal cardiovascular development is involved in the pathogenesis of AF. In this study, the coding exons and splice sites of the NKX2-5 gene, which encodes a homeodomain-containing transcription factor essential for cardiovascular genesis, were sequenced in 146 unrelated patients with lone AF as well as the available relatives of the mutation carriers. A total of 700 unrelated ethnically matched healthy individuals used as controls were genotyped. The disease-causing potential of the identified NKX2-5 variations was predicted by MutationTaster and PolyPhen-2. The functional characteristics of the mutant NKX2-5 proteins were analyzed using a dual-luciferase reporter assay system. As a result, two heterozygous NKX2-5 mutations, including a previously reported p.E21Q and a novel p.T180A mutation, were identified in two families with AF transmitted in an autosomal dominant pattern. The mutations co-segregated with AF in the families with complete penetrance. The detected substitutions, which altered the amino acids highly conserved evolutionarily across species, were absent in 700 control individuals and were both predicted to be causative. Functional analyses demonstrated that the NKX2-5 mutants were associated with significantly decreased transcriptional activity compared with their wild-type counterpart. The findings expand the spectrum of NKX2-5 mutations linked to AF and provide additional evidence that dysfunctional NKX2-5 may confer vulnerability to AF, suggesting the potential benefit for the early prophylaxis and personalized treatment of AF.

A novel noninvasive method for measuring fractional flow reserve through three-dimensional modeling

Coronary stenosis with lumen diameter reduction greater than 50% is recognized as coronary artery disease (CAD) [1–4]. Fractional flow reserve (FFR) is an epicardial lesion-specific parameter to determine the functional coronary stenosis, which is determined by pressure difference and resistance [5–8]. Previous studies have demonstrated that FFR guided percutaneous coronary intervention (PCI) could improve outcomes compared with anatomical invasive coronary angiography (ICA) guided PCI [6–10]. This study aims to overcome the deficiencies of invasive FFR and create a novel noninvasive FFR (FFRni). A 70-year-old female patient, diagnosed with CAD, stable angina pectoris, cardiac function III, essential hypertension III (very high-risk group), with blood pressure of 140/85 mm Hg, was enrolled in as a pilot study. Coronary computed tomography angiography (CCTA) was performed using multi-detector computed tomography scanners (Lightspeed 16 Pro). Original images were spilt into thin layers and directly exported into imaging control software MIMICS and processed to form an image sequence. Three-dimensional (3D) geometric models of the narrow coronary arteries including the right coronary artery (RCA), left anterior descending coronary (LAD) and left circumflex artery (LCX) were reconstructed and exported. Then, the geometric model was meshed with 3D Flotran elements in ANSYS software. Finite element analysis (FEA) was applied to analyze the velocity and pressure distribution of selected coronary arteries. Given boundary conditions including average velocity measured by transthoracic Doppler echocardiography with an ultrasound system (Sequoia C256) were applied in an inlet of 3D model. By setting the proper iteration time, the calculation went smoothly. ICA, as the “gold standard”, was performed with standard techniques. Invasive coronary angiography indicated that there was around 80% stenosis in the proximal RCA (Figure 1A). Mild (about 30%) stenosis in the proximal LAD and a diffuse lesion of the LCX (the narrowest was 80%) could also be quantified (Figure 2A). Additionally, the coronal section of CCTA images demonstrated moderate (around 60%) obstructive stenosis in the proximal RCA (Figure 1B). The cross-sectional images indicated 30% stenosis in the proximal and first branch segment of the LAD and diffuse patchy calcified plaques in the LCX leading to intermediate (50%) stenosis (Figure 2B). The diagnostic performance of FFRni was generally consistent with the results of ICA and CCTA. The values of proximal RCA, LAD and distal LCX were 0.73, 0.76 and 0.64, respectively, which suggested the severity of lesion-specific functional ischemia in distal myocardium with 0.75 as the cutoff value (Figures 1C and ​and2C2C). Figure 1 Anatomically obstructive stenosis of right coronary artery (RCA) with a lesion causing ischemia. A – Invasive coronary angiography indicates that stenosis is about 80% in the proximal RCA (black arrow). B – Multi-planar reformat of coronary ... Figure 2 Anatomically obstructive stenosis of left anterior descending coronary (LAD) and left circumflex artery (LCX) with/without functional ischemia. A – Invasive coronary angiography indicates that there exist 30% stenosis in proximal LAD (black arrow) ... Recently, FFR computed from CCTA (FFRCT) was reported. A good correlation between FFRCT and invasive FFR was certified through a randomized clinical controlled trial on 159 vessels in 103 patients [11]. The differences in the calculation process of FFRCT and FFRni in our study mainly reflect the following factors. During FFRCT calculation, coronary flow and pressure are unknown. A method to couple lumped parameter models of the microcirculation to the outflow boundaries of the 3D model was adopted. As a result of the cumbersome workload, it takes approximately 5 h/exam. We utilized FEA of the Flotran CFD module to solve the hemodynamic calculation under given boundary conditions. Therefore, it can greatly reduce the computation time to 3 h/exam. The more relaxed equipment requirements and faster inspection time guarantee potential clinical application of FFRni. Fractional flow reserve is a well-evaluated functional index to assess the ischemic significance of coronary lesions, helping making the decision of revascularization [12–14]. Nevertheless, the invasiveness and costliness are two major reasons restricting its further application. Finite element analysis and CFD over digital 3D modeling were applied in this pilot study and created a novel method to evaluate functional coronary stenosis by FFRni, which showed good consistency with ICA and CCTA. The superiority of no invasiveness and cost-effectiveness establishes the foundation of FFRni for its further applications in clinical practice. However, a large randomized clinical controlled trial assessed by FFRni compared with invasive FFR is urgently needed.

Expression characteristics of neutrophil and mononuclear-phagocyte related genes mRNA in the stable angina pectoris and acute myocardial infarction stages of coronary artery disease

Objective To investigate expression differences of neutrophil and mononuclear phagocyte related gene mRNAs among acute myocardial infarction (AMI), stable angina (SA) and control groups, and then discuss their expression characteristics in the stable angina pectoris (SAP) and AMI stages of coronary artery disease (CAD). Methods Whole Human Genome Oligo Microarrays were applied to assess the differential expression characteristics of neutrophil and mononuclear phagocyte related mRNAs in patients with AMI (n = 20), SA (n = 20) and controls (n = 20). Results (1) Almost all colony-stimulating factors (CSF) and their receptors related mRNAs was up-regulated in AMI and SA groups compared with the control group, and the expression of granulocyte-macrophage colony stimulating factor receptor (GM-CSFR) and granulocyte colony stimulating factor receptor (G-CSFR) mRNAs in the AMI group was significantly up-regulated compared with the other two groups (P < 0.01). (2) The expression of mRNAs related to monocyte chemoattractant protein-1 (MCP-1), CCR2 (MCP-1 receptor) and CXCR2 (IL-8 receptor) was significantly up-regulated (P < 0.01) in AMI group compared with SA and control groups. IL-8 mRNA expression in the AMI group was clearly higher than the controls (P < 0.05). (3) All mRNAs expression related to opsonic receptors (IgG FcR and C3bR/C4bR) was significantly up-regulated in AMI group compared with SA and control group (P < 0.01), and the SA group showed an upward trend compared with controls. (4) Most pattern recognition receptor (PRR)-related mRNAs expression was up-regulated in AMI group compared with SA and control groups. Most toll-like receptor (TLR) mRNAs expression was significantly up-regulated (P < 0.01) than the SA and control groups; macrophage scavenger receptor (MSR) mRNA was significantly up-regulated in AMI group compared with the control group (P < 0.01), and the SA group showed an upward trend compared with the controls. Conclusions The expression of most neutrophil and mononuclear-macrophage function related genes mRNAs was significantly up-regulated by stages during the progression of CAD, suggesting that the adhesive, chemotactic and phagocytic functions of neutrophil and mononuclear-macrophage were strengthened in the occurrence and development of coronary atherosclerosis and AMI. This also showed a stepped upward trend as the disease progressed.

VE/VCO2 slope and its prognostic value in patients with chronic heart failure.

The minute ventilation/carbon dioxide production (VE/VCO2) slope has been widely demonstrated to have strong prognostic value in patients with chronic heart failure (CHF), and the risk of mortality is believed to increase when the VE/VCO2 slope is >32.8; however, there is little evidence concerning the prognostic value of the VE/VCO2 slope in Chinese patients. In the present study, the prognostic value of the VE/VCO2 slope was investigated in patients with CHF. A total of 258 subjects underwent symptom-limited cardiopulmonary exercise testing (CPET) and were divided into CHF (113 males and 16 females; LVEF <0.49) and control (106 males and 23 females) groups. The cardiac-related events over a median 33.7-month follow-up period subsequent to the CPET were evaluated using receiver operating characteristic curve analysis. The VE/VCO2 slope was significantly different between the CHF and control groups (P<0.001). The area under the curve (AUC) for the VE/VCO2 slope in predicting cardiac-related mortalities in the patients with CHF was 0.670 (P<0.05), and the sensitivity and specificity of the VE/VCO2 slope were 0.667 and 0.620, respectively. The optimal threshold of the VE/VCO2 slope for predicting cardiac-related mortalities in patients with CHF was ≥39.3. The AUC for the VE/VCO2 slope in predicting cardiac-related hospitalizations in patients with CHF was 0.682 (P<0.05), and the sensitivity and specificity of the VE/VCO2 slope were 0.631 and 0.778, respectively. The optimal threshold of the VE/VCO2 slope for predicting cardiac-related hospitalizations in patients with CHF was ≥32.9. In conclusion, ventilatory efficiency decreases in patients with CHF. The VE/VCO2 slope is a strong predictor of cardiac-related mortalities in the patients with CHF analyzed.

Transcriptome and miRNA network analysis of familial hypercholesterolemia.

Familial hypercholesterolemia (FH) is a genetic disorder characterized by a high serum concentration of low-density lipoprotein (LDL) cholesterol. The high LDL cholesterol level leads to an excess deposition of cholesterol in the arterial walls and accelerated atherosclerosis, thereby increasing the risk of premature coronary heart disease. In the present study, we used a DNA microarray approach to identify gene expression profiles that distinguish patients with FH from healthy control subjects. Furthermore, transcription factors (TFs), microRNAs (miRNAs), target genes and pathways were analyzed to explore the potential transcriptional interactions occurring in FH. Publicly available microarray and regulation data were used to construct a regulatory network to identify additional genes related to FH and their interactions. The results revealed that specificity protein 1 (SP1), signal transducer and activator of transcription 1 (STAT1) and spleen focus forming virus (SFFV) proviral integration oncogene spi1 (SPI1) play a central role in the FH regulatory network. In addition, the TF, upstream transcription factor 2, c-fos interacting (USF2) and the gene, Wiskott-Aldrich syndrome (WAS), were identified to be associated with FH, although no reports for these proteins exist in the literature. Overall, transcriptional network analysis proved to be effective approach to identify novel targets for FH therapy.

Immune Cell Repertoire and Their Mediators in Patients with Acute Myocardial Infarction or Stable Angina Pectoris

Background: To evaluate the natural innate and adaptive immunity through gene expression and cytology levels in peripheral blood mononuclear cells in patients with acute myocardial infarction (AMI), stable angina pectoris (SAP) and controls. Methods: 210 patients with AMI, 210 with SAP, and 250 clinical controls were recruited. Whole human genome microarray analysis was performed in 20 randomly chosen subjects per group were examined to detect the expressions of complement markers, natural killer cells, T cells and B cells. The quantity of these cells and related cytokines as well as immunoglobulin levels were measured in all subjects. Results: In AMI group, the mRNA expressions of late complement component, markers of natural killer cells, CD3+, CD8+ T cells and B cells were down-regulated, while those of early complement component and CD4+T cells were up-regulated (p<0.05). In both AMI and SAP patients, the quantity of natural killer cells, CD3+, CD8+ T cells, B cells, IgM and IgG were significantly lower than those of the controls. CD4+ T cells, CH50, C3, C4, IL-2, IL-4, IL-6 and IFN-γ were significantly higher (p<0.05). Conclusions: In AMI patients, both of gene expressions related to complement, natural killer cells, CD3+, CD8+ T cells, B cells and the quantity of these immune cells decreased while cell number reduced in SAP patients. Immune function in both AMI and SAP patients decreased especially in AMI patients with declined gene and protein levels. To improve the immune system is a potential target for medical interventions and prevention in AMI.

The Prognostic Value of Peak Cardiac Power Output in Chinese Patients with Chronic Heart Failure.

Background Cardiopulmonary exercise testing has been widely used to risk stratify patients with chronic heart failure (CHF). Peak oxygen consumption (peakVO2) was regarded as a powerful predictor of survival, as it is a surrogate for peak cardiac output (CO), which by most is considered the “true” measure of heart failure. Therefore, it is reasonable to hypothesize that CO is an even stronger predictor than peak VO2. The present study is aimed to investigate the prognostic value of peak cardiac power output (peak CPO) in comparison with peakVO2 in Chinese patients with CHF. Methods Participants provided written informed consent to participate in this study. Totally 129 patients with CHF underwent symptom-limited cardiopulmonary exercise testing (CPET), with mean age 59.1±11.4 years, 87.6% male, 57.4% ischemic etiology, body mass index (BMI) 24.7±3.7 kg/m2 and LVEF 38±9%. CO was measured using an inert gas rebreathing method. The primary endpoints are cardiac deaths. Results Over median 33.7-month follow-up, 19 cardiac deaths were reported. Among peak VO2,VE/VCO2 slope and Peak CPO, their area under ROC were 0.64, 0.67, 0.68, respectively (Ρ<0.05).The optimal thresholds for predicting cardiac deaths were peak VO2≤13.4 ml.kg-1.min-1, and VE/VCO2 slope≥39.3 and peak CPO≤ 1.1 respectively by ROC analysis. Finally, in patients with a peak VO2≤13.4 ml.kg-1.min-1 those with peak CPO>1.1W had better survival than those with peak CPO ≤ 1.1W. However, by multivariate analysis adjusted for age, sex, BMI, resting heart rate, LVMI, LVEF, Peak CPO was not an independent predictor of cardiac deaths (P> 0.05). Conclusions Peak CPO was not a predictor of cardiac death in Chinese CHF patients.