Paeonol Pretreatment Attenuates Anoxia-Reoxygenation Induced Injury in Cardiac Myocytes via a BRCA1 Dependent Pathway.

Breast cancer type 1 sensitive protein (BRCA1) is a well-known tumor suppressor and its role in oxidative stress has been confirmed. The purpose of this study is to evaluate whether paeonol has a protective effect on myocardial hypoxia-reoxygenation (A/R) injury, and to explore H9C2 cells through a mechanism-dependent pathway mediated by BRCA1. H9C2 cells were pretreated with paeonol (10 µM) for 18 h before hypoxia was induced to establish a cell model of myocardial ischemia/reperfusion (I/R) injury. Use commercial kits to detect antioxidant indicators, including relative oxygen content (ROS) levels, total antioxidant capacity (T-AOC), superoxide dismutase (SOD), lactate dehydrogenase (LDH) activity, and creatine kinase (CK-MB) and nuclear factor-kappaB (NF-κB) activity. The cell viability was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction method. Real-time fluorescent quantitative PCR was used to detect BRCA1 mRNA and protein levels. The expression levels of BRCA1, NLRP3 and ACS were determined by Western blotting. In addition, the release of interleukin (IL)-1ß (IL-1ß), IL-6 and tumor necrosis factor-α (TNF-α) was also evaluated by an enzyme-linked immunosorbent assay (ELISA) kit. The results showed that paeonol (10 µM) can significantly improve the hypoxic A/R damage of H9C2 cells, and the BRCA1 expression of H9C2 cells pretreated with paeonol was significantly increased before A/R damage was induced. BRCA1 is widely known in breast and ovarian cancer. Our data proves that the down-regulation of BRCA1 participates in the decrease of cell viability and the decrease of CK-MB and LDH activities, and protects cells by inhibiting the production of ROS and the activation of Nod-like receptor protein 3 (NLRP3) inflammasomes and NF-κB. In conclusion, paeonol significantly improved the A/R damage of H9C2 cells induced by hypoxia through the BRCA1/ROS-regulated NLRP3 inflammasome/IL-1ß and NF-κB/TNF-α/IL-6 pathways. It may be a potential drug against myocardial I/R injury.

Transplantation of Endothelial Progenitor Cells Overexpressing miR-126-3p Improves Heart Function in Ischemic Cardiomyopathy.

BACKGROUND: In a previous study, a low level of miR-126-3p in endothelial progenitor cells (EPCs) was linked to the outcome of ischemic cardiomyopathy (ICM) patients. However, it remains unclear whether transplantation with miR-126-3p-overexpressing EPCs (MO-EPCs) can improve the cardiac function of ICM animal models. Methods and Results: miR-126-3p overexpression by lentiviral vector significantly increased migration and tube-like structures of EPCs from ICM patients. MO-EPCs or non-modified EPCs (NM-EPCs) were transplanted into nude rats with ICM induced by coronary artery ligation. MO-EPC transplantation increased capillary density and EPC survival rate in myocardial tissues of nude rats. Cytokines were also assessed by antibody array and real-time RT-PCR. G-CSF, VEGF-A, IL-3, IL-10, IGF-1, angiogenin, HGF, TIMP-1 and TIMP-2 were upregulated, and IL-8, MCP-1, MCP-2, TNF-α, TNF-ß and MIP-1ß were downregulated after miR-126-3p overexpression in EPCs. The same results were obtained in infarction tissues of nude rats after MO-EPC transplantation. Eight weeks after MO-EPC transplantation, left ventricular function improved significantly with clearly decreased infarction size, increased anterior wall thickness, and inhibition of inflammation compared with the results for NM-EPC transplantation. However, MO-EPC transplantation showed no increase in survival time of nude rats with ICM during 8 weeks of observation. CONCLUSIONS: miR-126-3p can restore the biology of EPCs from ICM patients. Moreover, MO-EPC transplantation improves cardiac function effectively, representing a promising future treatment for ICM.

Acute Hemodynamic Effects of Remote Ischemic Preconditioning on Coronary Perfusion Pressure and Coronary Collateral Blood Flow in Coronary Heart Disease.

BACKGROUND: The aim of this study was to assess the acute hemodynamic effects of remote ischemic preconditioning (RIPC) on coronary perfusion pressure and coronary collateral blood flow. METHODS: A total of 17 patients with coronary heart disease with severe (70%-85%) stenosis in one or two vessels confirmed by angiography were enrolled into this study. They were randomly divided into the RIPC group (9 patients) and the control group (8 patients). Distal pressure of coronary artery stenosis before balloon dilation (non-occlusive pressure, Pn-occl) and distal coronary artery occlusive pressure (Poccl) during balloon dilation occlusion were measured in all patients. The patients in the RIPC group received three cycles of lower limb ischemia-reperfusion preconditioning (5 minutes inflation of a blood pressure cuff, followed by 5 minutes reperfusion). For controls, the cuff was not inflated. After this process, Pn-occl and Poccl were measured again in each patient. RESULTS: There were no significant differences in angiographic characteristics between the two groups (all p > 0.05). Troponin I (TNI) levels after percutaneous coronary intervention (PCI) were lower in the RIPC group than in the control group (p = 0.004). In the RIPC group, mean Pn-occl and Poccl were significantly increased after RIPC compared to before RIPC [(72.78 ± 10.10) mmHg vs. (79.67 ± 9.79) mmHg, p = 0.002, (20.89 ± 8.61) mmHg vs. (26.78 ± 10.73) mmHg, p = 0.001, respectively]. CONCLUSIONS: RIPC can improve distal coronary perfusion pressure and rapidly increase distal coronary occlusive pressure thereby improving coronary collateral blood flow.

Myocardial protection of early extracorporeal membrane oxygenation (ECMO) support for acute myocardial infarction with cardiogenic shock in pigs.

The aim of this study was to explore myocardial protection of early extracorporeal membrane oxygenation (ECMO) support for acute myocardial infarction with cardiogenic shock in pigs. 24 male pigs (34.6 ± 1.3 kg) were randomly divided into three groups-control group, drug therapy group, and ECMO group. Myocardial infarction model was created in drug therapy group and ECMO group by ligating coronary artery. When cardiogenic shock occurred, drugs were given in drug therapy group and ECMO began to work in ECMO group. The pigs were killed 24 h after cardiogenic shock. Compared with in drug therapy group, left ventricular end-diastolic pressure in ECMO group decreased significantly 6 h after ligation (P < 0.05). At the end of the experiments, LV - dp/dt among three groups was significantly different, drug therapy group < ECMO group < control group. There was no difference in LV + dp/dt between drug therapy group and ECMO group. Compared with drug group, myocardial infarct size of ECMO group did not reduce significantly, but myocardial enzyme and troponin-I decreased significantly. Compared with drug therapy, ECMO improves left ventricular diastolic function, and may improve systolic function. ECMO cannot reduce myocardial infarct size without revascularization, but may have positive effects on ischemic areas by avoiding further injuring.

Advanced glycation endproducts trigger autophagy in cadiomyocyte via RAGE/PI3K/AKT/mTOR pathway.

UNLABELLED: Previous studies showed that the accumulation of advanced glycation end products (AGEs) induce cardiomyocyte apoptoisis, leading to heart dysfunction. However, the effect of AGEs on another cell death pathway, autophagy, in cardiomyocytes remains unknown. METHODS: Rat neonate cardiomyocytes were cultured and treated with AGEs at different concentration. Two classic autophagy markers, microtubule-associated protein 1 light chain 3 (LC3) and Beclin-1, were detected by western blot assay. The inhibition of RAGE and phosphatidylinositol 3-phosphate kinase (PI3K)/Akt/mTOR pathway were applied to cells, respectively. RESULTS: AGEs administration enhanced the expression of Beclin-1 and LC3 II in cardiomyocytes, increased the number of autophagic vacuoles and impaired the cell viability in dose-dependant manners. Also, AGEs inhibited the PI3K/Akt/mTOR pathway via RAGE. Inhibition of RAGE with RAGE antibody reduced expression of Beclin-1 and LC3 II/I and inhibited the cellular autophagy, accompanied by the reactivation of PI3K/Akt/mTOR pathway in cultured cells. Notably, the presence of inhibition of PI3K/Akt/mTOR pathway abolished the protective effect of RAGE inhibition on cardiomyocytes. CONCLUSION: This study provides evidence that AGEs induces cardiomyocyte autophagy by, at least in part, inhibiting the PI3K/Akt/mTOR pathway via RAGE.

Role of stromal cell-derived factor-1 in patients with non-ST elevation acute coronary syndrome.

The predictive value of stromal cell-derived factor-1 (SDF-1) has not been established in patients with non-ST elevation acute coronary syndrome (non-STEACS). A total of 678 consecutive patients with non-STEACS and moderate to high TIMI (Thrombolysis In Myocardial Infarction) risk scores were recruited. All patients underwent an early invasive strategy and then were followed-up for 18 months for clinical events. Left ventricular remodeling was assessed by echocardiography. Plasma concentrations of SDF-1 and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were analyzed. SDF-1 level was an independent predictor of left ventricular remodeling (OR = 2.95, 95% CI = 2.02-4.30, P < 0.001). Cox regression analysis demonstrated that both SDF-1 and NT-proBNP levels were significant independent predictors of death, myocardial infarction, or heart failure (HR = 2.45, 95% CI = 1.71-3.50, P < 0.001; HR = 3.71, 95% CI = 2.41-5.70, P < 0.001, respectively). The area under the ROC curves for SDF-1 (0.776) and NT-proBNP (0.817) were similar. The logistic model with both markers yielded a larger area under the ROC curve (0.862) than that of SDF-1 (P < 0.001) or NT-proBNP (P = 0.0001) alone. In patients stratified by NT-proBNP (above 615.4 pmol/L), SDF-1 (above 2175.1 pg/mL) was associated with poorer outcome (P < 0.001). Findings were similar for death and heart failure as individual endpoints. In non-STEACS, higher SDF-1 levels were a significant predictor of death, myocardial infarction, or heart failure independently of baseline clinical characteristics and NT-proBNP, and the combination of SDF-1 and NTproBNP significantly improved risk stratification. These data highlight the prognostic value of multiple, complementary biomarkers in non-ST elevation acute coronary syndrome.

Common variants in adiponectin gene are associated with coronary artery disease and angiographical severity of coronary atherosclerosis in type 2 diabetes.

BACKGROUND: Adiponectin, an adipokine facilitating insulin action, has antiatherogenic effects. This study investigated whether common single nucleotide polymorphisms (SNPs) in the adiponectin gene influenced plasma adiponectin level and whether they were associated with the risk of coronary artery disease (CAD) and its angiographical severity in type 2 diabetes in Chinese population. METHODS: 11 tagging SNPs were genotyped in 1110 subjects with or without CAD in type 2 diabetes. Variants of adiponectin gene were determined by Taqman polymerase chain reaction method. The plasma adiponectin concentrations were measured by sandwich enzyme-linked immunosorbent assay. The severity and extent of coronary atherosclerosis were assessed using the angiographic Gensini score and Sullivan Extent score. RESULTS: Among the 11 SNPs, the minor G allele of SNP rs266729 was significantly associated with higher odds of CAD (odds ratio (95% CI) = 1.49 (1.10 - 2.16), P = 0.022) after adjusting for covariates. In stepwise multivariate logistic regression, SNP rs266729 was a significant independent factor of CAD. Multivariate linear regression analysis revealed that rs266729 (ß = -0.101, P < 0.0001), rs182052 (ß = -0.044, P = 0.0035), and rs1501299 (ß = 0.073, P < 0.0001) were significantly associated with adiponectin level, and also indicated that the minor G allele of SNP rs266729 had higher Gensini score (ß = 0.139, P < 0.001) and Sullivan Extent score (ß = 0.107, P < 0.001). Haplotypes analysis revealed different haplotype distributions in case and control subjects (P = 0.0003), with two common haplotypes GGG and GAG of the rs266729, rs182052, and rs1501299 being associated in heterozygotes with a greater than threefold increase in cardiovascular risk (odds ratio (95% CI)=3.39 (1.83 - 6.30), P = 0.0001). CONCLUSIONS: In our population, genetic variants in the adiponectin gene influence plasma adiponectin levels, and one of them is a strong determinant of CAD susceptibility and its angiographical severity in type 2 diabetes. This study has provided further evidence for a role of adiponectin in the development of CAD.

[Curative effects on standardized management of community patients with coronary heart disease complicated with chronic heart failure].

OBJECTIVE: To explore the effects on the standardized management of patients with coronary atherosclerotic heart disease complicated with chronic heart failure. METHODS: A total of 823 patients discharged from our department were randomly enrolled. Among 734 patients with follow-up consents, they were divided into management and control groups (n = 440, 294). The management group received standardized out-of-hospital management, regular health education and follow-ups of telephone and outpatient visits. RESULTS: Compared with the control group, the management group had lower rates of all-cause mortality, cardiac death and readmission due to cardiovascular events (CVE) declining by 26.5%, 32.2% and 57.0% respectively. Over a 4-year period, the annular survival rate of management group was 92%, 85%, 83% and 82% while that of control group 95%, 89%, 82% and 75% respectively. Patient compliance of digoxin and diuretics in the control group was inferior to that in the management group. CONCLUSION: Through standardized out-of-hospital management, the patients with coronary atherosclerotic heart disease plus chronic heart failure may achieve significant benefits through reducing the rates of all-cause mortality, cardiac death and readmission due to CVE and improving survival rate.

Impact of plaque characteristics on percutaneous coronary intervention-related microvascular dysfunction: insights from angiographic microvascular resistance and intravascular ultrasound.

Background: The correlation between percutaneous coronary intervention (PCI)-related microvascular dysfunction (MVD) and plaque characteristics remains unclear. To investigate this correlation and its prognosis, we assessed changes in MVD by angiographic microvascular resistance (AMR) and intracoronary ultrasound scans after PCI. Methods: We conducted a retrospective study that enrolled 250 patients with coronary artery disease between July 2016 and December 2018. We collected demographic characteristics, laboratory tests, coronary angiography (CAG) and intracoronary ultrasound findings. We calculated quantitative flow ratio (QFR) and AMR by CAG. The endpoint was vessel-oriented composite outcomes (VOCOs). Results: After 47 exclusions, we divided 203 cases into a deteriorated group (n=139) and an improved group (n=64) based on AMR change after PCI. Compared with the improved group, the deteriorated group had smaller lumen area [3.03 (interquartile range, 2.20-3.91) vs. 3.55 mm2 (interquartile range, 2.45-4.57), P=0.033], higher plaque burden [78.92% (interquartile range, 73.95-82.61%) vs. 71.93% (interquartile range, 62.70-77.51%), P<0.001], and higher proportion of lipidic components (13.86%±4.67% vs. 11.78%±4.41%, P=0.024). Of 186 patients who completed 4.81±1.55 years follow-up, 56 developed VOCOs. Receiver-operating characteristic (ROC) curve analysis showed post-PCI AMR and VOCOs correlation (area under the curve: 0.729, P<0.001). Multivariate regression analysis showed post-PCI AMR >285 mmHg·s/m correlated with adverse outcome (hazard ratio =4.350; 95% confidence interval: 1.95-9.703; P<0.001). Conclusions: Intravascular ultrasound (IVUS) imaging and AMR revealed an association of post-PCI MVD with a smaller lumen area, more severe plaque burden, and a higher percentage of lipidic components. Post-PCI MVD was an independent risk factor for poor prognosis.

[Comparative analysis between cardiopulmonary exercise testing and echocardiography in patients of heart failure with normal ejection fraction].

OBJECTIVE: To assess the clinical and predictive value of cardiopulmonary exercise testing (CPET) used in heart failure with normal left ventricular ejection fraction (HFNEF). METHODS: A total of 49 HFNEF patients of (New York Heart Association) NYHA class II were randomly selected from September 2010 to July 2012. The parameters of CPET and ultrasonic cardiogram (UCG) were collected at Day 3 post-admission. Person's and partial correlations were used to perform to compare CPET and UCG. RESULTS: Pearson's correlation revealed that mitral peak velocity of early filling/early diastolic mitral annular velocity (E/E', 10.14 ± 2.05) was significantly correlated with peak oxygen uptake (VO2 peak, (24.15 ± 8.31) ml×kg⁻¹×min⁻¹, r = -0.287, P = 0.046), carbon dioxide production (VCO2, (1.63 ± 0.51) L/min, r = -0.429, P = 0.002), partial pressure of end-tidal carbon dioxide (PET CO2, (39.50 ± 7.77) mm Hg, r = -0.282, P = 0.050) and minute ventilation/carbon dioxide production (VE/VCO2, 31.69 ± 5.32, r = 0.411, P = 0.003). Early diastolic mitral annular velocity (E', (6.46 ± 1.60) cm/s) was relevant to VO2 peak (r = 0.351, P = 0.013), VCO(2) (r = 0.452, P = 0.001), PET CO2 (r = 0.310, P = 0.030), VE/VCO2 (r = -0.434, P = 0.002) and respiratory exchange ratio (RER, 1.18 ± 0.13, r = 0.350, P = 0.014). After adjustment, VCO2 was correlated with E/E' (r = -0.369, P = 0.019) and E' (r = 0.393, P = 0.010). VE/VCO2 was relevant to E/E' (r = 0.414, P = 0.006) and E' (r = -0.334, P = 0.031). CONCLUSION: For HFNFE patients, CPET has high values of assessment and prognosis.

Adiponectin inhibits lymphotoxin-ß receptor-mediated NF-κB signaling in human umbilical vein endothelial cells.

Adiponectin exerts anti-diabetic and anti-atherogenesis properties through its 2 receptors (AdipoR1 and AdipoR2). However, the signaling pathways responsible for the anti-inflammatory effects of adiponectin are largely unknown. In this study, we identified the lymphotoxin (LT)-ß receptor (LTBR) as an interacting partner of human AdipoR1 by using a yeast two-hybrid screening. The interaction between LTBR and AdipoR1 was confirmed by co-immunoprecipitation and co-localization analysis. Furthermore, adiponectin incubation inhibited lymphotoxin-induced NF-κB activation and the expression of adhesion molecules in human umbilical vein endothelial cells. These results indicated that AdipoR1 interacted with LTBR and mediated the inhibition of LTBR-activated NF-κB pathway.

Association between transforming growth factor beta1 polymorphisms and left ventricle hypertrophy in essential hypertensive subjects.

Left ventricular hypertrophy (LVH) increases the risk of cardiovascular morbid events in hypertension. TGF-beta1 is involved in pathologic states such as cardiac hypertrophy and cardiac fibrosis; we thus postulate that the TGF-beta1 polymorphism is related to LVH in hypertensives. Six hundred and eighty essential hypertensive patients were recruited. Biochemical variables and clinical data were obtained and the determination of LVH was performed by echocardiography. According to the presence of LVH, all subjects were divided into the LVH+ and LVH- group. DNA was obtained, and two coding region polymorphisms of the TGF-beta1 gene (+869 Leu-->Proat codon 10 and +915 ARG-->Pro at codon 25) were analyzed by the polymerase chain reaction. The product was cleaved with the restriction endonucleases. For the polymorphisms of the +869 Leu-->Pro at codon 10, there was no marked difference in the distributions of genotypes and the allele frequencies between the LVH+ and LVH- subjects. For +915 Arg-->Pro at codon 25, a significant difference in the distributions of genotypes of TGF-beta1 was observed. The left ventricular mass index (LVMI) in Arg-Pro genotype carriers was significantly higher than those in the Arg-Arg and Pro-Pro carriers. Multivariate analysis showed that the Arg-Pro genotype was an independent risk factor for LVH (OR 3.23, 95% CI [1.48-5.63, P = 0.002]). The codon 10 genotypes did not show a significant association to LVH. Our data revealed a genetic association of TGF-beta1+915 Arg-->Pro at codon 25 polymorphism with LVH in a Chinese hypertensive population.

[Management of coronary atherosclerotic heart disease through an alliance of community and hospital].

OBJECTIVE: To evaluate the effect of out-hospital normalized management of coronary heart disease (CAD) on the end point events such as mortality, readmission, etc, and on the compliance of patients through normalized management by an alliance of community and hospital. METHODS: The samples were comprised of a total of 2000 patients in 15 communities. And 1642 patients agreed to a follow-up and signed a consent form. Ten communities were chosen as the intensive management group in which community clinicians were trained and the patient management plan was proposed and carried out. The remaining 5 communities were taken as the control group in which the community clinicians were not trained and the patients received only general management. Both groups received a follow-up of 23 months. RESULTS: Compared with the control group, the intensive manage group showed a lower risk of all-cause death, cardiac death and readmission due to cardiovascular events (CVE). They declined by 36.5% (OR 0.635, 95%CI 0.478-0.854), 41.5% (OR 0.585, 95%CI 0.428-0.800) and 56.1% (OR 0.439, 95%CI 0.315-0.612) respectively. The proportion of patients with NYHA III in the intensive management and control groups increased by 3.6% and 7.7% while that of the counterparts of NYHAIV in two groups increased by 1.6% and 6.4% respectively. The cardiac function in the patients of intensive management group was significantly superior to that in control group. Patients in both groups displayed an acceptable compliance to cardiac medications except for aspirin. The proportion of aspirin in the intensive management and control groups increased by 8.4% and 8.7% respectively (P<0.05). CONCLUSION: Through normalized management provided by an alliance of community and hospital, the rates of all-cause death and readmission due to CVE decrease significantly concurrently with an improvement of cardiac function and quality of life in CAD patients.

Coronary plaque tissue characterization in patients with premature coronary artery disease.

Premature coronary artery disease (CAD) studies rarely involve coronary plaque characterization. We characterize coronary plaque tissue by radiofrequency intravascular ultrasound (IVUS) in patients with premature CAD. From July 2015 to December 2017, 220 patients from the Department of Cardiology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine with first occurrence of angina or myocardial infarction within 3 months were enrolled. Patients with premature CAD (n = 47, males aged < 55 years, and females aged < 65 years) or later CAD (n = 155) were retrospectively compared for cardiovascular risk factors, laboratory examination findings, coronary angiography data, gray-scale IVUS, and iMap-IVUS. The mean age was 53.53 ± 7.24 vs. 70.48 ± 8.74 years (p < 0.001). The groups were similar for traditional coronary risk factors except homocysteine (18.60 ± 5.15 vs. 17.08 ± 4.27 µmol/L, p = 0.043). After matching for baseline characteristics, LDL cholesterol (LDL-C) was higher for premature CAD than later CAD (2.50 ± 0.96 vs. 2.17 ± 0.80 mmol/L, p = 0.019). Before the matching procedure, the premature CAD group had shorter target lesion length [18.50 (12.60-32.00) vs. 27.90 (18.70-37.40) mm, p = 0.002], less plaque volume [175.59 (96.60-240.50) vs. 214.73 (139.74-330.00) mm3, p = 0.013] than the later CAD group. After the matching procedure, the premature CAD group appeared to be less plaque burden (72.69 ± 9.99 vs. 74.85 ± 9.80%, p = 0.005), and positive remodeling (1.03 ± 0.12 vs. 0.94 ± 0.18, p = 0.034), and lower high risk feature incidence (p = 0.006) than the later CAD group. At the plaque's minimum lumen, premature CAD had more fibrotic (p < 0.001), less necrotic (p = 0.001) and less calcified areas (p = 0.012). Coronary plaque tissue was more fibrotic with less necrotic and calcified components in premature than in later CAD, and the range and degree of atherosclerosis were significantly lower.

Receptor for activated C-kinase 1, a novel binding partner of adiponectin receptor 1.

Adiponectin is an adipose tissue derived hormone with anti-diabetic and insulin-sensitizing properties. Two adiponectin receptors, AdipoR1 and AdipoR2, have recently been identified, yet the signaling pathways triggered through adiponectin receptors remain to be elucidated. Using a yeast two-hybrid screen, we identified an adaptor protein, receptor for activated protein kinase C1 (RACK1), as an interacting partner of human AdipoR1. RACK1 was confirmed to interact with AdipoR1 by co-immunoprecipitation and co-localization analysis in mammalian cells. The interaction was enhanced by adiponectin stimulation. In addition, the knockdown of RACK1 by RNA interference inhibited adiponectin-stimulated glucose uptake in HepG2 cells. These results suggest that RACK1 may act as a key bridging factor in adiponectin signaling transduction through interacting with AdipoR1.

[Mechanism of cardioprotection induced by noninvasive limb ischemic preconditioning].

OBJECTIVE: To verify the inhibitory effect of mitochondrial calcium uniporter in remote preconditioning-induced cardioprotection. METHODS: By occlusion and reperfusion of left anterior descending artery, the rat hearts were subjected to 30 min regional ischemia and 120 min reperfusion in vivo. Thus the ischemic reperfusion model was established. The rats were randomly assigned to undergo one of the following maneuvers: (1) remote preconditioning; (2) ruthenium red (an inhibitor of mitochondrial calcium uniporter); (3) spermine or SB202190 (an opener of mitochondrial calcium uniporter). Remote preconditioning was elicited by three cycles of 5 min of right femoral artery occlusion interspersed with 5 min of reperfusion. The mean arterial blood pressure, heart rate and lactate dehydrogenase released in plasma were measured during reperfusion but the infarct size was measured after reperfusion. RESULTS: In comparison with I/R group, remote preconditioning limited infarct size [(20.4 +/- 2.5)% vs (51.0 +/- 6.0)%] and lactate dehydrogenase release [(271 +/- 9) U/L vs (339 +/- 39)U/L] during reperfusion. On the contrary, spermine or SB202190 attenuated the reduction of infarct size and lactate dehydrogenase release induced by remote preconditioning. The group of spermine was [(40.8 +/- 9.2)% vs (20.4 +/- 2.5)%] and [(383 +/- 43) U/L vs (271 +/- 9) U/L] while the group of SB202190 was [(44.3 +/- 6.8)% vs (20.4 +/- 2.5)%] and [(356 +/- 26) U/L vs (271 +/- 9) U/L]. CONCLUSION: Inhibition of mitochondrial calcium uniporter opening is involved in the remote preconditioning-induced cardioprotection.

The G501C polymorphism of oxidized LDL receptor gene [OLR-1] is associated with susceptibility and serum C-reactive protein concentration in Chinese essential hypertensives.

BACKGROUND: Oxidized LDL receptor gene 1 (OLR-1) polymorphism is reportedly associated with several cardiovascular conditions. However, its relationship with essential hypertension remains unknown. The aim of this study is to explore the association of OLR-1 polymorphism at position 501 in the open reading frame (G501C), with the susceptibility of essential hypertension. METHODS: 2-hundred eighty Chinese essential hypertensive and 284 control subjects were enrolled and genetic study was performed. The clinical data, i.e., sex, age, blood pressure, body mass index, smoking history, lipid profile and serum C-reactive protein concentration in both hypertensives and controls were obtained. RESULTS: A significant difference in OLR-1 genotype distributions was noted between the hypertensives and the controls (GG: 67.9% vs. 70.8%; GC: 20.0% vs. 23.6%; CC: 12.1% vs. 5.6%, P=0.021). For G and C allele frequencies, the difference between these 2 groups was significant as well (G: 67.5% vs. 23.5%, C: 82.6% vs. 17.4%, P=0.011). Logistic regression analysis revealed that the CC genotype is an independent risk factor for hypertension (OR=3.036, 95% CI: 1.572-6.174, P=0.016). Furthermore, when the serum C-reactive protein concentration in the hypertensive group was studied according to OLR-1 genotypes, the serum CRP concentration in CC homozygous carriers were found significantly higher than that in GC and GG carriers (1.53+/-0.32, 1.31+/-0.32 and 2.94+/-1.29 respectively, P=0.002). CONCLUSIONS: The CC genotype of OLR-1 G501C polymorphism is associated with susceptibility and serum C-reactive protein concentration in Chinese essential hypertensive population.

Gender-specific effect of estrogen receptor-1 gene polymorphisms in coronary artery disease and its angiographic severity in Chinese population.

BACKGROUND: The role of common polymorphisms of the estrogen receptor-1 in coronary artery disease (CAD) and it association with angiographic severity reminds conflicting in sexes and different races. METHODS: Two-hundred ten angiographically defined Chinese CAD patients and 174 control subjects were enrolled. DNA was obtained and the polymorphisms were analyzed by the polymerase chain reaction. The region containing the PvuII T/C and the XbaI A/G sites was amplified. PCR product was cleaved with the restriction endonucleases. RESULTS: No significant differences in PvuII and XbaI genotype and allele frequencies were noted between the CAD and controls.However, when stratified by gender, we noticed the PvuII genotype and allele frequencies were significantly different between CAD and controls, but in male group only, not in female group. Diabetes, hypertension, high LDL levels and the PvuII CC genotype were independent risk factors for CAD. PvuII CC was associated with the angiographic severity of CAD measuring by the number of diseased vessels as well. For XbaI, no association was found with the CAD susceptibility before and after gender stratification. CONCLUSION: This study revealed a gender-specific effect of PvuII polymorphism in Chinese CAD subjects. PvuII gene polymorphisms affect CAD susceptibility in man only. The PvuII CC is a risk factor for CAD and it is associated with angiographic CAD severity.

[The study on inhabiting endothelial cell aging by targeted silencing of p22phox].

The aim of the study was to determine the importance and possible mechanism of NAD (P)H oxidase subunits P (superscript 22phox) involved in human umbilical endothelial cell lines ECV-304 aging by special short interference RNA (siRNA). Three siRNAs targeting p22phox were designed and synthesized in vitro, which were used to transfect ECV-304 cultured in vitro for selecting the most powerful and most suitable transfection concentration and time. The cell line ECV-304 was divided into three groups: control group, angiotensin II (Ang II) group, siRNA group, and Ang II + siRNA group. Cell aging was identified by beta-gal stain. Reactive oxygen species (ROS) and NO level in cells and medium were measured. RT-PCR and Western blot were used to analyze mRNA and protein expression of NAD(P)H oxidase subunit p22phox. Among the 3 siRNAs, siRNA-1 was the most powerful on gene silence with 50 nmol/L transfection concentration at 24 h and 36 h. The number of positive cells stained by beta-gal were increased in ECV-304 stimulated with Ang II, and p22phox mRNA and protein expression were increased in aging ECV-304 stimulated with Ang II, which had lower NO and higher ROS. Compared with Ang II group, ROS level was decreased and NO level was increased in Ang+siRNA group with decreased aging level. The result of the present study suggested that siRNA could induce NAD(P)H oxidase subunit p22phox gene silence, Ang II could induce ECV-304 aging cultured in vitro, and the possible pathway of endothelial cell aging is that Ang II upregulates p22phox expression, and then enhances the cell ROS level.