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Abstract: Circulating endothelial progenitor cells (EPCs) play a key role in restoring endothelial function and enhancing angiogenesis. However, the effects of low-dose aspirin on circulating EPCs are not well known. We investigated the effects of low-dose aspirin on EPC migration, adhesion, senescence, proliferation, apoptosis and endothelial nitric oxide synthase (eNOS) expression. EPC migration was detected by a modified Boyden chamber assay. EPC adhesion assay was performed by counting adherent cells on fibronectin-coated culture dishes. EPC senescence was assessed by both senescence-associated-β-galactosidase staining and DAPI staining. EPC proliferation was analyzed by MTT assay. EPC apoptosis was evaluated by flow cytometric analysis. eNOS protein expression was measured by Western blotting analysis. Aspirin promoted EPC migratory and adhesive capacity at concentrations between 0.1 and 100μmol/L and prevented senescence at concentrations between 50 and 100μmol/L. Meanwhile, aspirin in a range of these concentrations did not affect EPC proliferation, apoptosis or eNOS expression. Our findings indicate that low-dose aspirin promotes migration and adhesion and delays the onset of senescence of EPCs. [Copyright &y& Elsevier]

The aim of this present study is to investigate the impacts of combinatorial simvastatin administration and endothelial progenitor cell (EPC) transplantation on therapeutic angiogenesis in an athymic nude mouse model of hind limb ischemia. Athymic nude mice were divided into four groups ( n = 10/group): vehicle administration plus PBS injection (control), simvastatin administration plus PBS injection (simvastatin), vehicle administration plus EPC transplantation (EPC), and simvastatin administration plus EPC transplantation (combination). The combination therapy had the greatest laser Doppler blood perfusion imager (LDPI) index and capillary density among the four groups. Importantly, this combination therapy significantly reduced apoptosis of ischemic skeletal muscle cells in part through downregulation of Bax and upregulation of Bcl-2 compared with the other groups. Moreover, the combination therapy exhibited the highest efficacy of increasing the ratio of phospho-Akt to Akt among the four groups. Taken together, the simvastatin and EPC combination therapy promotes powerful angiogenesis in hindlimb ischemia. The combination therapy not only inhibites apoptosis of ischemic skeletal muscle cells partially via downregulation of Bax and upregulation of Bcl-2, but also activates Akt phosphorylation significantly. These efficacies may be mediated by the angiogenic potency of simvastatin, EPCs, and by the beneficial effects of simvastatin on transplanted EPCs as well. [ABSTRACT FROM AUTHOR]

Ginkgolide B (GB) is a diterpene lactone found in the leaves of the traditional Chinese medicinal plant Ginkgo that has been shown to have various pharmacological effects. However, the anti-apoptotic properties of GB in cardiovascular disease remain poorly understood. The present study aimed to investigate the effect of GB on hydrogen peroxide-induced cell injury in cardiac H9c2 cells, and to further clarify its protective mechanism of action. An in vitro hydrogen peroxide-treated H9c2 cell model was used in order to mimic myocardial ischemia-reperfusion (I/R) injury. Cell viability was assessed by the Cell Counting Kit-8 assay. The induction of apoptosis was determined by flow cytometry and staining was performed using Hoechst 33342. In addition, the effect of GB on the expression levels of apoptosis-associated proteins was evaluated by western blot analysis. The present study demonstrated that GB protected against hydrogen peroxide-induced cytotoxicity and cell apoptosis in H9c2 cardiac cells. GB upregulated the expression level of the anti-apoptotic protein Bcl-2 and downregulated the expression levels of the pro-apoptotic proteins cleaved caspase-3 and Bax in hydrogen peroxide-treated H9c2 cells. The molecular mechanism underlying the anti-apoptotic effects of GB was subsequently detected. GB pretreatment activated the PI3K/Akt/mTOR signaling pathway and caused an increase in the phosphorylation levels of Akt and mTOR in hydrogen peroxide-treated H9c2 cells. These results revealed that GB inhibited hydrogen peroxide-induced apoptosis in H9c2 cells via activation of the PI3K/Akt/mTOR signaling pathway. These findings indicate the potential therapeutic benefits of GB in the treatment of myocardial I/R injury. [ABSTRACT FROM AUTHOR]

Background. The aim of the present study was to observe the effect of RAGE-HMGB1 signal pathway on remote ischemic postconditioning in mice with myocardial ischemia reperfusion injury. Methods. Mice model of MIRI was established and randomly divided into three groups: control group, ischemia reperfusion group, and remote ischemic postconditioning group. Infarction size was detected by Evans blue and TTC staining. Cardiac function was detected by echocardiography measurement. The protein levels of RAGE, HMGB1, P-AKT, and ERK1/2 were detected by Western blot 120 min following reperfusion. Results. RIPostC could decrease the infarct size and increase LVEF and FS compared with I/R group. Two hours after myocardial ischemia reperfusion, the levels of RAGE and HMGB1 were significantly decreased in RIPostC group compared with those in I/R group. The level of p-AKT was significantly higher in the RIPostC group than in the I/R group. LY294002 significantly attenuated RIPostC-increased levels of Akt phosphorylation. Conclusion. RIPostC may inhibit the expression of RAGE and HMGB1 and activate PI3K/Akt signaling pathway to extenuate ischemic reperfusion injury in mice. It could further suppress the oxidative stress, have antiapoptosis effect, and reduce inflammatory reaction, but this effect has certain timeliness. [ABSTRACT FROM AUTHOR]

Background: Hepatocyte growth factor (HGF) is widely known as a protective factor in ischemic myocardium, however HGF sensitive cellular mechanism remained ill-defined. Autophagy at early stage of hypoxia has been demonstrated to play a role in protecting myocardium both in vivo and vitro. We performed this study to investigate the association between the protective effect of HGF and autophagy. Methods: Ventricular myocytes were isolated from neonatal rat heart (NRVMs). We evaluated cardiomyocytes apoptosis by Hoechst staining and flow cytometry. Autophagy was assessed by transmission electron microscope and mRFP-GFPLC3 adenovirus infection. Mitochondrial membrane potential was estimated by JC-1 staining. Western blotting and ELISA assay were used to quantify protein concentrations. Results: We found that autophagy in NRVMs increased at early stage after hypoxia and HGF release was consistent with the change of autophagy. Exogenous HGF enhanced autophagy and decreased apoptosis, while neutralizing HGF yielded opposite effects. Besides, inhibition of autophagy increased apoptosis of myocytes. Furthermore, exogenous HGF induced Parkin, the marker of mitochondrial autophagy, indicating increased clearance of injured mitochondria. Conclusions: Our results revealed a potential mechanism in which exogenous HGF prevented NRVMs from apoptosis after hypoxia. Upregulation of Parkin through administration of exogenous HGF may be a potential therapeutic strategy ptotecting myocytes during ischemia. [ABSTRACT FROM AUTHOR]

Abstract: Iodinated contrast media (CM) can induce apoptosis and necrosis of renal tubular cells. The injuries of endothelial cells induced by CM on the systemic condition have not been fully understood. To assess the toxic effects of non-ionic CM on the glomerular and aortic endothelial cells, iopromide and iodixanol, two kinds of representative non-ionic CM, were used for the in vivo study. Sixty aged rats were respectively received the agents or normal sodium intravascularly. No obvious apoptosis and morphological change was detected in the glomerular and aortic endothelial cells apart from renal tubules after CM administration. However, expressions of the nitric oxide synthase (eNOS) in glomerular endothelium were decreased at 12h after CM injection. Furthermore, plasma creatinine and endothelin-1 were increased and plasma nitric oxide (NO) was decreased significantly after CM administration. However, we failed to observe the significant increase of plasma von Willebrand Factor. These results suggest that non-ionic iodinated CM do not induce apoptosis and necrosis of glomerular and aortic endothelial cells in vivo. Decreased eNOS expression and increased plasma endothelin-1 may be involved in non-ionic iodinated CM-induced endothelial dysfunction and kidney injury. [Copyright &y& Elsevier]

Abstract: Objective: Calcium-sensing receptors (CaSRs) are G-protein coupled receptors which maintain systemic calcium homeostasis and participate in hormone secretion, activation of ion channels, cell apoptosis, proliferation, and differentiation. Previous studies have shown that CaSRs induce apoptosis in isolated adult rat heart and in normal neonatal rat cardiomyocytes by G-protein-PLC-IP3 signaling transduction. However, little knowledge is presently available concerning the role of CaSRs in the apoptosis induced by ischemia and reperfusion in neonatal cardiomyocytes. Methods: Primary neonatal rat ventricular cardiomyocytes were incubated in ischemiamimetic solution for 2 h, and then re-incubated in normal culture medium for 24 h to establish a model of simulated ischemia/reperfusion (I/R). Cardiomyocyte apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). The expression of CaSRs mRNA was detected by real-time reverse transcription polymerase chain reaction (RT-PCR). In addition, the expressions of caspase-3 and Bcl-2 were analyzed by western blot. Results: The simulated I/R enhanced the expression of CaSRs and cardiomyocyte apoptosis. GdCl3, a specific activator of CaSRs, further increased the expression of CaSRs and cardiomyocyte apoptosis, along with up-regulation of caspase-3 and down-regulation of Bcl-2. Conclusion: CaSRs are associated with I/R injury and apoptosis in neonatal rat ventricular cardiomyocytes via suppressing Bcl-2 and promoting caspase-3 expression. [Copyright &y& Elsevier]