Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; therapeutic use ; Hypolipidemic Agents ; therapeutic use ; Pharmacogenetics

Atherosclerosis ; metabolism ; Cyclooxygenase 2 ; metabolism ; Humans

OBJECTIVETo explore the possible relationship between the ultrastructural characteristics of pulmonary veins and the pathogenesis of atrial fibrillation originating from pulmonary veins.

METHODSThe pulmonary veins from domestic pigs were serially sectioned (2 mm) transversely along the vessels. The odd number sections were fixed in 10% phosphate buffered formalin solution and the even number sections were fixed in 3% Glutaral for further electron microscopy observations.

RESULTSTwo cell types were found in the pulmonary veins of pigs. One cell type was the P-like cells that had an empty-appearing cytoplasm containing only sparse myofibrils and small mitochondria, both of which were randomly distributed. Another cell type was slender transitional cells with plenty of longitudinally displayed myofibrils.

CONCLUSIONP-like cells in the pig pulmonary veins were found using electron microscopy in this study and ectopic beats from P-like cells in the myocardial sleeves in the pulmonary veins might be responsible for atrial fibrillation originating from pulmonary veins.

Animals ; Microscopy, Electron ; Myocytes, Cardiac ; ultrastructure ; Pulmonary Veins ; ultrastructure ; Swine

OBJECTIVEDendritic cells play an important role in the pathogenesis of atherosclerosis. To explore the effects of hyperglycemia on the maturation and immune function of human monocyte derived dendritic cells (MDCs).

METHODSImmature MDCs were cultured in RPMI1640 medium with either 5.5 mmol/L D-glucose (NG), 25 mmol/L D-glucose (HG) or 5.5 mmol/L D-glucose + 19.5 mmol/L mannitol (HM) in the absence or presence of 30 mmol/L N-acetylcysteine [NAC, a reactive oxygen species inhibitor (ROS)] for 48 hours. FACS was used to investigate the MDCs immunophenotypic expression. Immune function was evaluated by allogeneic mixed T lymphocyte reaction and measurement of cytokine levels from culture supernatants. Intracellular ROS production in MDCs was also measured by 2', 7'-dichlorodihydrofluorescein (DCF, 10 micromol/L) fluorescence using confocal laser-scanning microscopy techniques.

RESULTSCompared with NG and HM treated MDCs, the expression of maturation markers such as CD1a, HLA-DR, CD83, CD86 were significantly upregulated, allogeneic T cells proliferation as well as the cytokines secretions (IL-2, IL-12, IL-10 and IFN-gamma) significantly increased in HG treated MDCs. Intracellular ROS production in MDCs was also significantly increased and all these stimulatory effects of HG could be partially attenuated by NAC.

CONCLUSIONHigh glucose promote the maturation of MDCs and augment their capacity to stimulate T-cell proliferation and cytokine secretions at least in part through enhancing intracellular ROS generation. These stimulating effects of high glucose on MDCs maturation may be one of the mechanisms of accelerated atherosclerosis found in patients with diabetes.

Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Culture Media ; Cytokines ; biosynthesis ; Dendritic Cells ; drug effects ; immunology ; metabolism ; Glucose ; adverse effects ; pharmacology ; Humans ; Immunophenotyping ; Monocytes ; cytology ; Reactive Oxygen Species ; metabolism ; T-Lymphocytes ; cytology

OBJECTIVETo selectively knockdown the expression of Angiotensin II receptor subtype 1a (AT1aR) in rat vascular smooth muscle cells (VSMCs) by RNA interference and the sequential effects on cellular viability and proliferation.

METHODSThe primary cultured rat aortic VSMCs were transfected by plasmids pAT1a-shRNA1 and pAT1a-shRNA2, each carrying an U6 promoter and an AT1a-specific shRNA-coding template sequence, or by a control plasmid pGenesil-Control (pCon) carrying a nonspecific shRNA-coding sequence. The mRNA and protein expressions of AT1a, AT2 were analyzed by semi-quantified RT-PCR and Western blot, respectively and normalized to the internal control gene beta-actin. Cellular viability and proliferation were determined with methylthiazoletetrazolium (MTT) assay.

RESULTSAT1a mRNA and protein were reduced by 82% and 69% by pAT1a-shRNA1, 77% and 56% by pAT1a-shRNA2, respectively while no change was found in pCon treated VSMCs. AT2 receptor level in VSMCs remains unchanged after various treatments. The A(490nm) values obtained by MTT measurements were similar among groups in the absence of Ang II but decreased significantly in pAT1a-shRNA1 and pAT1a-shRNA2 treated VSMCs in the presence of Ang II.

CONCLUSIONRNA interference can selectively knockdown AT1a expression in cultured VSMCs and attenuate the Ang II induced cell proliferation. Future studies are warranted to explore the potential role of RNA interference on AT1 function and as a new gene therapy tool for cardiovascular diseases.

Animals ; Cells, Cultured ; Gene Knockdown Techniques ; Male ; Muscle, Smooth, Vascular ; metabolism ; Plasmids ; RNA Interference ; RNA, Small Interfering ; Rats ; Rats, Sprague-Dawley ; Receptors, Angiotensin ; metabolism ; Transfection

OBJECTIVEPhosphorylation of myosin light chain (MLC) is one of the most important steps for vascular smooth muscle contraction and Rho-kinase is involved in this process. We investigated the role of Rho-kinase in a porcine coronary artery spasm model with interleukin-1beta.

METHODSSegments of left coronary artery adventitia were surrounded by normal saline (n = 8) or IL-1beta agarose microne (n = 8) for 2 weeks. Vasospastic responses to intracoronary serotonin or histamine then studied at the saline or IL-1beta-treated site. The Rho-kinase mRNA expression in the treated site was measured by reverse transcription-polymerase chain reaction analysis (RT-PCR). The extent of phosphorylation of myosin-binding subunit of myosin phosphates (MBS, one of the major substrates of Rho-kinase) were quantified by Western blot analysis.

RESULTSIntracoronary serotonin or histamine repeatedly induced coronary artery spasm and coronary arterial stenosis was evidenced at IL-1beta-treated site. Expression of Rho-kinase mRNA in IL-1beta-treated site was significantly increased compared to saline treated site (98.20% +/- 7.66% vs. 63.70% +/- 4.26%, P < 0.05). Western blot analysis showed that during the serotonin-induced contractions the extent of phosphorylation of MBS was also significantly increased in the spastic site (25,485 +/- 4745 vs. 6510 +/- 779, P < 0.05).

CONCLUSIONRho-kinase upregulation at the spastic site and increased phosphorylation of myosin-binding subunit of myosin phosphates are key players in inducing vascular smooth muscle hypercontraction in this porcine model.

Animals ; Coronary Vasospasm ; metabolism ; pathology ; Disease Models, Animal ; Interleukin-1beta ; adverse effects ; metabolism ; Male ; Myosin Light Chains ; metabolism ; Phosphorylation ; RNA, Messenger ; metabolism ; Swine ; rho-Associated Kinases ; metabolism

OBJECTIVETo investigate whether p53 pathway participates in the effect of emodin on vascular smooth muscle cell proliferation.

METHODSThe effects of emodin on vascular smooth muscle cell proliferation were evaluated by cell count, senescent-associated beta-galactosidase staining, and annexin V staining. DNA synthesis was determined by (3)H-thymidine corporation, cell cycle was analyzed by FACS, the p53 protein level was measured by Western blot and cDNA expression array technology was used to demonstrate the effect of emodin on the simultaneous expression of a large number of genes in cultured vascular smooth muscle cells.

RESULTSEmodin at 1.6-3.1 microg/ml inhibited VSMC growth, at 6.3-12.5 microg/ml promoted VSMC aging and induced VSMC apoptosis at 25.0 microg/ml 24 hours after exposure. Unscheduled DNA synthesis, which was a sensitive indicator for DNA injury, was observed in VSMC following 24 hours emodin exposure. The mRNA and protein levels of p53 were up-regulated in a concentration-dependent manner. Proliferation/carcinogenesis-related genes were down-regulated and other genes related to cell senescence, apoptosis, and DNA damage/repair were up-regulated in VSMC after exposure to emodin for 24 hours. Emodin readily permeated VSMC membrane and mostly located in the cytoplasm and few of them in the nucleus.

CONCLUSIONSThe p53 pathway in VSMC was activated post emodin exposure in a concentration-dependent manner and which might be responsible for the observed antiproliferative effects of emodin in vascular smooth muscle cells.

Apoptosis ; drug effects ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; DNA Damage ; Emodin ; pharmacology ; Humans ; Myocytes, Smooth Muscle ; cytology ; drug effects ; metabolism ; RNA, Messenger ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

OBJECTIVESalt-sensitivity plays an important role in essential hypertension and is associated with more severe target organ injury and higher mortality in patients with essential hypertension. However, the pathologic mechanism of salt-sensitivity is poorly understood and endothelial dysfunction might be involved in salt-sensitive hypertension. We, therefore, observed the endothelial function changes by measuring plasma and urine nitric oxide (NO) concentrations in salt-sensitive (SS) normotensive and mild hypertensive subjects underwent various salt loading protocols and the effects of potassium supplement.

METHODSThirty-nine normotensive and mild hypertensive subjects (< 160/100 mm Hg), aged 16-60, were enrolled and the study protocol is as follows: 3 days baseline investigation, 1 week low-salt loading (3 g/day), 1 week. high-salt loading (18 g/day) and 1 week high-salt loading plus potassium chloride (4.5 g/day).

RESULTSPlasma and urine NO levels were significantly lower in SS (n = 8) subjects at baseline, low-salt and high-salt loading phases compared with salt-resistant subjects (SR, n = 31) and oral potassium supplement to SS subjects with high salt loading significantly increased plasma and urine NO levels.

CONCLUSIONEndothelial function is impaired in normotensive and mild hypertensive SS subjects. Oral potassium supplement could improve endothelial function in normotensive and mild hypertensive SS subjects.

Adult ; Antihypertensive Agents ; Blood Pressure ; Endothelium ; physiology ; Female ; Humans ; Hypertension ; epidemiology ; physiopathology ; Male ; Nitric Oxide ; blood ; urine ; Potassium, Dietary ; administration & dosage

OBJECTIVETo compare the changes of both inward rectifying K(+) (Kir) current(I(k1)) density and mRNA expression level of Kir2.1, a major subfamily of Kir in chronic human atrial fibrillation (CAF) with those in normal sinus rhythm (NSR).

METHODSI(k1) density was measured with whole-cell patch clamp technique in single myocyte isolated by an enzymatic dissociation method from right atrial appendages in patients with CAF (n = 8) and those with NSR (n = 12). The mRNA expression levels of Kir2.1 was determined in right atrial appendages from CAF (n = 19) and NSR (n = 18) by semiquantitative reverse-transcription polymerase chain reaction (RT-PCR).

RESULTThe average resting membrane potentials were similar between CAF and NSR (-78.95 mV +/- 4.67 mV and -70.22 mV +/- 11.08 mV, P>0.05). I(k1) density in single myocyte significantly increased at hyperpolarized potential level (-100 mV) in CAF compared to that in NSR (-9.59 pA/pF +/- 2.47 pA/pF vs. -5.58 pA/pF +/- 2.52 pA/pF, P<0.01). The mRNA level of Kir2.1 was also significantly higher in CAF than that of NSR (0.50+/-0.16 vs. 0.34+/-0.09, P<0.05).

CONCLUSIONThe data suggest that Kir2.1 up-regulation and I(k1) current increase might contribute to the electrical remodeling in CAF patients.

Atrial Fibrillation ; genetics ; metabolism ; physiopathology ; Gene Expression ; Humans ; Myocytes, Cardiac ; metabolism ; physiology ; Patch-Clamp Techniques ; Potassium Channels, Inwardly Rectifying ; genetics ; metabolism ; RNA, Messenger ; genetics

OBJECTIVEHeart failure is responsible for a huge burden in hospital care. Our goal was to evaluate the value of N-terminal-pro-brain natriuretic peptide (Nt-proBNP) on predicting death or hospital readmission after hospital discharge in patients with chronic heart failure (CHF).

METHODSFrom March 2003 to April 2005, 135 consecutive patients (97 male and 38 female, mean age 60.7 years +/- 13.1 years) with chronic heart failure [dilated cardiomyopathy (44%) and coronary heart disease (35%)] were included in this study. Plasma concentrations of the Nt-proBNP were measured by ELISA on admission. All patients received conventional therapy and were followed up for 24 months. The primary end point was death or readmission.

RESULTS(1) During the follow up period (640 days +/- 100 days), 11 patients died and 39 patients rehospitalized, the median Nt-proBNP level on admission was significantly higher in patients died during the follow up period (5908 ng/L) than that of rehospitalized patients (2768 ng/L, P = 0.038). Plasma Nt-proBNP level on admission were significantly higher in primary end point group (n = 50, 2947 ng/L) than that in non-primary end point group (n = 85, 917 ng/L, P < 0.01). (2) Variables associated with an increased hazard of death and/or rehospitalization were Nt-proBNP and NYHA degree when analyzed by logistic regression models. Increased Log Nt-proBNP was the strongest independent predictor of an adverse outcome of CHF (odds ratio 13.8, 95% confidence interval 2.29 to 2.78, P < 0.01). (3) Area under the curve for Nt-proBNP in evaluating prognosis of CHF patients was 0.885 (positive predictive value 88.5%, negative predictive value 11.5%).

CONCLUSIONNt-proBNP level on admission is a strong predictor of rehospitalization and death within 24 months after hospital discharge in patients with chronic heart failure.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Cardiac Output, Low ; Chronic Disease ; Female ; Heart Failure ; blood ; diagnosis ; Humans ; Male ; Middle Aged ; Natriuretic Peptide, Brain ; blood ; Peptide Fragments ; blood ; Prognosis ; Ventricular Function ; Young Adult