Preliminary study of carotid variables under ultrasound analysis as predictors for the risk of coronary arterial atherosclerosis.

BACKGROUND: Carotid atherosclerosis by ultrasound scanning can be considered as an ideal window to reflect systemic artery atherosclerosis, which has aroused wide concern for predicting the severity of coronary artery atherosclerosis clinically. Ultrasound radio frequency (RF) data technology has enabled us to evaluate the carotid structure and elastic function precisely, for predicting the severity of coronary artery atherosclerosis. METHODS: Patients with suspected coronary artery disease (CAD) underwent coronary angiography and were assigned to four groups according to whether atherosclerotic plaque was found or not and it caused stenosis. Carotid artery intima-media thickness (IMT) and arterial stiffness were investigated by quality intima-media thickness (QIMT) and quality arterial stiffness (QAS) techniques during ultrasound scanning. Univariable and multivariable modeling were used to investigate correlations of carotid parameters to coronary artery atherosclerosis. Receive operating characteristic (ROC) curves were used to evaluate diagnostic performance of these ultrasound variables. RESULTS: Carotid IMT and stiffness variables pulse wave velocity (PWV), α, ß and compliance coefficient (CC) were statistically different between every two-group's comparisons. IMT correlated with stiffness variables significantly with r = 0.70, 0.77, 0.63, and -0.39, respectively. All variables correlated with the severity of coronary atherosclerosis with the odd ratio (OR) of 1.73, 1.67, 1.19, 1.23, and 0.56 accordingly as IMT, PWV, α, ß and CC were concerned. The AUC of IMT, PWV, α, ß and CC were 0.9257, 0.8910, 0.8016, 0.9383, 0.8581 with correctly classified rate of 88.16%, 83.77%, 78.07%, 86.84%, and 81.58%, respectively. CONCLUSIONS: Carotid artery IMT and stiffness variable PWV, α, ß and CC presented favorable predicting and differentiating values for patients with coronary atherosclerosis of different severity.

High-mobility group box 1 induces calcineurin-mediated cell hypertrophy in neonatal rat ventricular myocytes.

Cardiac hypertrophy is an independent predictor of cardiovascular morbidity and mortality. In recent years, evidences suggest that high-mobility group box 1 (HMGB1) protein, an inflammatory cytokine, participates in cardiac remodeling; however, the involvement of HMGB1 in the pathogenesis of cardiac hypertrophy remains unknown. The aim of this study was to investigate whether HMGB1 is sufficient to induce cardiomyocyte hypertrophy and to identify the possible mechanisms underlying the hypertrophic response. Cardiomyocytes isolated from 1-day-old Sprague-Dawley rats were treated with recombinant HMGB1, at concentrations ranging from 50 ng/mL to 200 ng/mL. After 24 hours, cardiomyocytes were processed for the evaluation of atrial natriuretic peptide (ANP) and calcineurin A expression. Western blot and real-time RT-PCR was used to detect protein and mRNA expression levels, respectively. The activity of calcineurin was also evaluated using a biochemical enzyme assay. HMGB1 induced cardiomyocyte hypertrophy, characterized by enhanced expression of ANP, and increased protein synthesis. Meanwhile, increased calcineurin activity and calcineurin A protein expression were observed in cardiomyocytes preconditioned with HMGB1. Furthermore, cyclosporin A pretreatment partially inhibited the HMGB1-induced cardiomyocyte hypertrophy. Our findings suggest that HMGB1 leads to cardiac hypertrophy, at least in part through activating calcineurin.

Evidence that apoptotic signalling in hypertrophic cardiomyocytes is determined by mitochondrial pathways involving protein kinase Cδ.

1. Cardiomyocyte apoptosis plays an important role in the transition from cardiac hypertrophy to heart failure. Hyper-trophic cardiomyocytes show an increased susceptibility to apoptotic stimuli, but the mechanisms remain unclear. 2. We hypothesized that activated protein kinase Cδ (PKCδ) associated with cardiomyocyte hypertrophy could move from the cytoplasm to mitochondria, and subsequently trigger the apoptotic signalling pathway. 3. Hypertrophy was induced in cultured neonatal rat cardiomyocytes using endothelin-1 (ET-1), insulin-like growth factor-1 (IGF-1), thyroid hormone (T(3) ) or angiotensin-II (AngII). AngII at high concentrations (1 and 10 nmol/L) also induced apoptosis. Hypertrophic cells were then treated with AngII with or without specific inhibitors of the angiotensin receptors AT(1) and AT(2) (losartan and PD123319, respectively), endothelin receptor A (BQ-123) and PKCδ (rottlerin). ET-1 plus AngII had a threefold and significant increase in apoptosis in the hypertrophic cultures compared with AngII alone. In association with the increase in apoptosis, this treatment also promoted mitochondrial translocation of PKCδ, and increased expression of cleaved caspase 9 and activity of caspase 3. All of these increases were modulated by concurrent use of the PKCδ inhibitor, rottlerin. 4. The results suggest that apoptotic signalling in hypertrophic cardiomyocytes is determined by mitochondrial pathways involving PKCδ.

Simvastatin inhibits angiotensin II-induced cardiac cell hypertrophy: role of Homer 1a.

1. The scaffolding protein Homer 1a is constitutively expressed in the myocardium, although its function in cardiomyocytes remains poorly understood. The aim of the present study was to investigate Homer 1a expression in hypertrophic cardiac cells and its role in angiotensin (Ang) II-induced cardiac hypertrophy. 2. After serum starvation for 24 h, cells were treated with 1 micromol/L simvastatin, 100 nmol/L angiotensin (Ang) II or their combination added to Dulbecco's modified Eagle's medium containing 0.5% serum. For combination treatment with AngII plus simvastatin, cells were exposed to simvastatin 12 h before the addition of AngII to the medium and cells were then incubated in the presence of both drugs for a further 24 h. Western blotting was used to determine Homer 1a protein expression. Hypertrophy was evaluated by determining the protein content per cell. 3. Homer 1a protein levels were upregulated following AngII-induced hypertrophy in H9C2 cells and neonatal rat cardiomyocytes, and these increases were augmented by simvastatin pretreatment. Concomitantly, simvastatin pretreatment inhibited extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and AngII-induced hypertrophy. 4. The inhibitory effects of simvastatin against AngII-induced hypertrophy were attenuated by Homer 1a silencing, suggesting that simvastatin suppresses cardiac hypertrophy in a Homer 1a-dependent manner. Furthermore, AngII-induced hypertrophy and ERK1/2 phosphorylation in neonatal rat cardiomyocytes were significantly inhibited following the overexpression of Homer 1a using an adenovirus. 5. These results suggest a possible role for Homer 1a in inhibiting cardiac hypertrophy perhaps in part through inhibition of ERK1/2 activation.

Dystrophin: from non-ischemic cardiomyopathy to ischemic cardiomyopathy.

Dystrophin and its associated proteins form a scaffold underneath the cardiomyocyte membrane and connect the intracellular cytoskeleton to the extracellular matrix. Dystrophin localizes at the X chromosome, whose mutations might result in Duchenne muscular dystrophy, Becker muscular dystrophy and X-linked dilated cardiomyopathy. In addition to these genetic dilated cardiomyopathies, some acquired dilated cardiomyopathy like viral dilated cardiomyopathy is also related to dystrophin disruption or aberrant cleavage. In this review, we summarize the structure and distribution of dystrophin and researches of dystrophin in genetic and viral dilated cardiomyopathy. Moreover, we hypothesize that dystrophin play a critical role in ventricular remodeling in ischemic myocardium and treatment targeting restoration of dystrophin onto membrane could benefit for ischemic cardiomyopathy.

[Protein kinase Cdelta is possibly involved in the transition from hypertrophy to apoptosis of myocardiocytes].

Cardiac hypertrophy is an adaptive process to an increased hemodynamic overload. However, the adaption may lead to the fragility of myocardium facing pathological stimuli. In the present study, experiments were designed to explore the susceptibility of hypertrophic myocardiocytes to apoptotic stimuli and the role of protein kinase Cdelta (PKCdelta) during the transition from hypertrophy to apoptosis. Endothelin-1 (ET-1)-treated cardiomyocytes were used as model of cardiac hypertrophy. Angiotensin II (Ang II) was used as an apoptotic stimulus. Cell surface area was measured to determine the extent of hypertrophy. The apoptotic rate in cardiomyocytes was detected by Hoechst 33258. (1) Cell surface area was increased by 42.5% and 67.3% following 1 nmol/L and 10 nmol/L ET-1 treatment, respectively, as compared with serum-free cultured myocytes. So the mildly and moderately hypertrophic myocyte models were set up. (2) Apoptotic rates in serum-free cultured, mildly and moderately hypertrophic myocytes after Ang II treatment were (15.54+/-1.32) %, (20.65+/-1.40) % and (29.33+/-3.52) %, respectively. It is suggested that hypertrophic myocytes are more susceptive to apoptotic stimulus. (3) Rottlerin, a specific inhibitor of PKCdelta depressed apoptotic rates induced by Ang II to (15.88+/-2.25) % in mildly hypertrophic myocytes and to (15.01+/-1.37) % in moderately hypertrophic myocytes; but rottlerin did not affect apoptotic rate induced by Ang II in serum-free cultured myocytes. These results suggest that inhibition of PKCdelta can reduce Ang II-induced apoptosis of hypertrophic cardiomyocytes and that PKCdelta is possibly involved in the apoptotic process of hypertrophic cardiomyocytes.

Validation of the Andon KD-5917 automatic upper arm blood pressure monitor, for clinic use and self-measurement, according to the European Society of Hypertension International Protocol revision 2010.

OBJECTIVE: To validate the Andon KD-5917 automatic upper arm blood pressure monitor according to the European Society of Hypertension International Protocol revision 2010. MATERIALS AND METHODS: Sequential same-left-arm measurements of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were obtained in 33 participants using the mercury sphygmomanometer and the test device. According to the validation protocol, 99 pairs of test device and reference blood pressure measurements (three pairs for each of the 33 participants) were obtained in the study. RESULTS: The device produced 73, 98, and 99 measurements within 5, 10, and 15 mmHg for SBP and 86, 98, and 99 for DBP, respectively. The mean ± SD device-observer difference was 3.07 ± 3.68 mmHg for SBP and -0.89 ± 3.72 mmHg for DBP. The number of patients with two or three of the device-observer difference within 5 mmHg was 26 for SBP and 29 for DBP, and no patient had a device-observer difference within 5 mmHg. CONCLUSION: The Andon KD-5917 automatic upper arm blood pressure monitor can be recommended for clinical use and self-measurement in an adult population on the basis of the European Society of Hypertension International Protocol revision 2010.

The long-term differentiation of embryonic stem cells into cardiomyocytes: an indirect co-culture model.

BACKGROUND: Embryonic Stem Cells (ESCs) can differentiate into cardiomyocytes (CMs) in vitro but the differentiation level from ESCs is low. Here we describe a simple co-culture model by commercially available Millicell™ hanging cell culture inserts to control the long-term differentiation of ESCs into CMs. METHODOLOGY/PRINCIPAL FINDINGS: Mouse ESCs were cultured in hanging drops to form embryoid bodies (EBs) and treated with 0.1 mmol/L ascorbic acid to induce the differentiation of ESCs into CMs. In the indirect co-culture system, EBs were co-cultured with epidermal keratinocytes (EKs) or neonatal CMs (NCMs) by the hanging cell culture inserts (PET membranes with 1 µm pores). The molecular expressions and functional properties of ESC-derived CMs in prolonged culture course were evaluated. During time course of ESC differentiation, the percentages of EBs with contracting areas in NCMs co-culture were significantly higher than that without co-culture or in EKs co-culture. The functional maintenance of ESC-derived CMs were more prominent in NCMs co-culture model. CONCLUSIONS/SIGNIFICANCE: These results indicate that NCMs co-culture promote ESC differentiation and has a further effect on cell growth and differentiation. We assume that the improvement of the differentiating efficiency of ESCs into CMs in the co-culture system do not result from the effect of co-culture directly on cell differentiation, but rather by signaling effects that influence the cells in proliferation and long-term function maintenance.