PARP-1 Involvement in Autophagy and Their Roles in Apoptosis of Vascular Smooth Muscle Cells under Oxidative Stress.

Autophagy and poly(ADP-ribose) polymerase 1 (PARP-1) are activated and involved in a series of cell processes under oxidative stress, which is associated with pathogenesis of atherosclerosis. Research on their relationship under oxidative stress has been limited. In this study, we aimed to investigate the activation, relationship, and role of autophagy and PARP-1 in vascular smooth muscle cell (VSMC) death under oxidative stress. This study explored the signal molecule PARP-1 and autophagy in VSMCs using gene silencing and the hydrogen peroxide (H2O2)-stimulated oxidative stress model. We observed that H2O2 could induce autophagy in VSMCs, and the inhibition of autophagy could protect VSMCs against oxidative stress-mediated cell death. Meanwhile, PARP-1 could also be activated by H2O2. Additionally, we analysed the regulatory role of PARP-1 in oxidative stress-mediated autophagy and found that PARP-1 was a novel factor involved in the H2O2-induced autophagy via the AMPK-mTOR pathway. Finally, PARP-1 inhibition protected VSMCs against caspase-dependent apoptosis. These data suggested that PARP-1 played a critical role in H2O2-mediated autophagy and both of them were involved in apoptosis of VSMCs.

[Relationship between the risk factors of coronary artery disease and degree of coronary artery plaques assessed by multi-detector row spiral computed tomography].

Objective: To assess the association of the traditional risk factors of coronary artery disease(CAD) and degree of coronary artery plaque. Methods: A total of 3 752 patients who had a suspicion of CAD from September 2011 to November 2012 at the First Hospital of China Medical University underwent the coronary artery computed tomography. The univariable and multivariable Logistic regression were employ to assess the association the traditional risk factors of CAD and degree of coronary artery plaque. Results: Age, diabetes, hypertension and smoking were the independent risk factor for significant stenosis, multivessel lesions and high coronary artery calcium score(all P <0.05), male was an independent risk factor for significant stenosis(P=0.039), however HDL-C was the independent protect factor(all P<0.05). Conclusion: Age, diabetes, hypertension and smoking are the independent risk factor for degree of coronary artery plaque, HDL-C is the independent protect factor.Male is only an independent risk factor for significant stenosis.

[Impact of olmesartan medoxomil on atherosclerosis lesions in apolipoprotein E knockout mice].

OBJECTIVE: To investigate the effect and possible mechanisms of olmesartan medoxomil on atherosclerosis of apolipoprotein E knockout (ApoE(-/-)) mice. METHODS: Sixteen 6-week-old male ApoE(-/-) mice were randomly divided into atherosclerosis model group fed with high fat diet, and olmesartan medoxomil intervention group fed with high fat diet and olmesartan medoxomil (10 mg·kg(-1)·day(-1,) per gavage). Eight C57BL/6 mice were fed with normal diet, and treated for 12 weeks.The blood pressure and the serum level of lipid were detected; the aorta were removed, oil red staining for plaque area, Hematoxylin and eosin (HE) staining for plaque morphology, Elastica van Gieson (EVG) staining for elastin, and picrosirius red (PSR) for collagen respectively; and the expression of cathepsin S (Cat S), smooth action protein (ASMA) and macrophage surface molecule-3 (Mac-3) were detected by immunohistochemisty analysis. RESULTS: Serum cholesterol and low density lipoprotein levels were significantly higher in atherosclerosis model group than in control group[(15.08±1.64) vs (2.06±0.15) mmol/L, (15.60±1.05) vs (0.00±0.00) mmol/L] (all P<0.01), while triglyceride level was similar between the two group.In contrast to model group, the mice in intervention group showed no statistical difference in blood pressure and plasma lipid levels, while the plaque areas in the aorta were significantly decreased (P<0.05) as well as the expression of Cat S and Mac-3[(2.4±1.2) vs (8.8±3.2)%, (2.2±1.2) vs (7.2±2.8)%] (all P<0.01). In addition, the elastin levels, collagen contents, and the expression of ASMA remained significantly higher compared with model group (P<0.05). CONCLUSION: Olmesartan medoxomil could slow down the atherosclerosis process, the possible mechanism was implicated with the suppression of Cat S and decreased inflammatory responses alongside the increased elastin and collagen contents.

Synchronization of time-delayed chemically coupled burst-spiking neurons with correlated noises.

Synchronization of two time-delayed chemically coupled neurons with burst-spiking states is studied. Different from the previous study by N. Buric et al. (Phys. Rev. E 78, 036211 (2008)), it is found that exactly synchronous burst-spiking dynamics can occur for small coupling strengths and time delays. The results are confirmed by common time delays and non-equal time delays. When common noise is added to the two neurons, synchronization is enhanced as noise strength is increased. But the results are different for larger time delay and smaller time delay. When noises are correlated, it is found that only strong noises with large correlation coefficient can induce exact synchronization. Even one percent of independent noises can influence synchronization much.

Predicting the synchronization time in coupled-map networks.

An analytical expression for the synchronization time in coupled-map networks is given. By means of the expression, the synchronization time for any given network can be predicted accurately. Furthermore, for networks in which the distributions of nontrivial eigenvalues of coupling matrices have some unique characteristics, analytical results for the minimal synchronization time are given.

Coexistence of anticipated and layered chaotic synchronization in time-delay systems.

We study the dynamic stabilities of unidirectionally coupled linear arrays of chaotic oscillators with time-delay feedbacks in star configuration, and find that if all oscillators in the network are identical, then the oscillators in the linear arrays can anticipate the driving oscillators, and simultaneously the oscillators in the linear arrays with the same position with respect to the central one are in synchronous chaotic state. Compared with the anticipated synchronization, the layered synchronization is first generated and last destroyed as the coupling constant is increased. This coexistence of anticipated and layered chaotic synchronization is destroyed by long time feedback. If the driving and driven oscillators are different, then only layered chaotic synchronization is possible.

Layered synchronous propagation of noise-induced chaotic spikes in linear arrays.

Stable propagation of noise-induced synchronous spiking in uncoupled linear neuron arrays is studied numerically. The chaotic neurons in the unidirectionally coupled linear array are modeled by Hindmarsh-Rose neurons. Stability analysis shows that the synchronous chaotic spiking can be successfully transmitted to cortical areas through layered synchronization in the neural network under certain conditions of the network structure.

Long-time anticipation of chaotic states in time-delay coupled ring and linear arrays.

We study the time-delay and unidirectionally coupled ring and linear arrays of chaotic systems, and find that under certain conditions, the linear array can spatial periodically "copy" the chaotic dynamics of the ring with very long anticipation times. Numerical calculations of the Lyapunov exponents show that the delay times can result in unsynchronized chaotic waves, periodic waves, and stable states in the ring that are replicated in the linear array, but have no effect on the absolute stability of the anticipatory synchronization. Our results show that such configurations can both enhance the absolute stability of the synchronization manifolds and minimize the effects of convective instabilities.

[Effects of a novel KATP channel opener JTV-506 on myocardial infarct size of isolated rat heart].

AIM: To study the influence of a novel KATP channel opener JTV-506(JTV) on cardiac function and myocardial infarct size of isolated rat heart. METHODS: The Langendorff apparatus was used to study the effect of JTV at different concentrations on the flow of coronary artery and the pressure of left ventricle. The effect of JTV on infarction size was observed on the isolated rat double coronary arteries perfusion model. RESULTS: JTV 1 mumol.L-1 increased the flow of coronary artery obviously. When the concentration reached 10 mumol.L-1, JTV decreased the systolic pressure of the left ventricle. JTV 1 mumol.L-1 reduced the myocardial infarct size whether it was administrated during both preischemic and ischemic period or only during ischemic period. This effect was completely blocked by glibenclamide, but when glibenclamide was administrated alone, it showed no obvious effect on infarct size. CONCLUSION: The KATP channel opener JTV can obviously dilate coronary artery and decrease cardiac systolic function when administrated at high doses. JTV was found to decrease the infarct size when administrated in doses that did not affect cardiac function. These effects were related to the opening of KATP channel.