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Qin S.,Peking University | Zhou W.,Hubei University of Medicine | Liu S.,Beijing Hospital of Integrated Traditional Chinese and Western Medicine | Chen P.,Central South University | Wu H.,Peking University
International Journal of Clinical and Experimental Medicine | Year: 2015

Bone mesenchymal stem cells (BMSCs) are able to differentiate into multi types of lineages, so they have been widely applied in the stem cell transplantation. The BMSCs are usually needed to be expanded before transplantation due to their limited content in bone marrow. It has recently been reported that Icariin (ICA), a major constituent of flavonoids from the Chinese medical herb Epimedium brevicornum Maxim, promotes the proliferation of various types of differentiated cells. However, whether ICA can enhance BMSCs proliferation and the possible underlying mechanisms are still unknown. After being isolated and purified from rat bone marrow, cultured BMSCs are stimulated with different concentrations of ICA. The cytotoxicity of ICA is evaluated by the Cell Counting Kit-8 (CCK-8) assay method and the ICA optimal concentration for BMSCs proliferation is determined at 320 μg/L. Our work reveals that ICA induces an obvious phosphorylation of ERK and p38 kinases in BMSCs, no matter serum exists or not. Inhibition of ERK or p38 MAPK signaling by their specific inhibitors PD98059 or SP600125, respectively, not only prevents the activation of these kinases, but also attenuates cell proliferation induced by ICA. Furthermore, the downstream transcription factors of MAPK pathway, Elk1, Stat3, c-Myc and Fos, are also monitored by RT-PCR, and our results show that among them, Elk1 and c-Myc are significantly upregulated after ICA treatment. Taken together, our results demonstrate that ICA promotes the proliferation of rat BMSCs through activating ERK and p38 MAPK signaling which further leads to upregulation of their downstream transcription factors Elk1 and c-Myc. Our work provides a novel effective way to expand the content of BMSCs in vitro, which casts light on clinical applications of stem cell transplantation in the future. © 2015, E-Century Publishing Corporation. All rights reserved. Source

Wu H.-J.,Peking University | Yang J.-Y.,Beijing Hospital of Integrated Traditional Chinese and Western Medicine | Jin M.,Beijing Hospital of Integrated Traditional Chinese and Western Medicine | Wang S.-Q.,Beijing Institute of Radiation Medicine | And 6 more authors.
Cellular Physiology and Biochemistry | Year: 2015

Background/Aims: Licorice has been used to treat many diseases, including palpitations, in both Eastern and Western societies for thousands of years. It has been reported that glycyrrhetinic acid (GA), an aglycone saponin extracted from licorice root, exerts protective effects on the cardiovascular system, limits infarct sizes and protects against the development of arrhythmia. However, the mechanisms underlying the effects of glycyrrhetinic acid on the cardiovascular system remain poorly understood. This study aimed to determine the mechanisms underlying the protective effects of GA against lethal cardiac arrhythmias induced via ischemia-reperfusion in rat hearts, and to examine its electropharmacological properties. Materials and Methods: Anesthetized rats were divided into control (CTL), GA5, GA10, and GA20 groups. GA was administered intravenously 15 min before the occlusion of the left anterior descending coronary artery, at dosages of 5, 10 and 20 mg/kg, respectively. Single ventricular myocytes were isolated using enzymolysis. The whole-cell patch clamp technique was utilized to record Ica, L, Ito and action potentials (APs). Results: During reperfusion, the incidence of ventricular fibrillation (VF) was decreased in each of the groups compared with the CTL group (p<0.05). The ventricular tachycardia (VT)/VF score was significantly decreased in the GA20 group. Action potential durations (APDs) were prolonged by GA; both L-type calcium current (Ica-L) and transient outward potassium current (Ito) were blocked in a concentration-dependent manner by GA. Conclusion: These results suggest that GA attenuates both the susceptibility to and the incidence of fatal ventricular arrhythmia during reperfusion in rat hearts via the prolongation of the APD and the inhibition of both Ica-L and Ito. GA appears to be a promising antiarrhythmic agent in the setting of ischemia/reperfusion. © 2015 S. Karger AG, Basel. Source

Yan X.,Peking University | Tian J.,Institute of Geriatric Cardiology | Wu H.,Peking University | Liu Y.,Beijing Hospital of Integrated Traditional Chinese and Western Medicine | And 6 more authors.
Evidence-based Complementary and Alternative Medicine | Year: 2014

Aim. To investigate the effect of Ginsenoside Rb1 (GS-Rb1) on hypoxia/ischemia (H/I) injury in cardiomyocytes in vitro and the mitochondrial apoptotic pathway mediated mechanism. Methods. Neonatal rat cardiomyocytes (NRCMs) for the H/I groups were kept in DMEM without glucose and serum, and were placed into a hypoxic jar for 24 h. GS-Rb1 at concentrations from 2.5 to 40 μM was given during hypoxic period for 24 h. NRCMs injury was determined by MTT and lactate dehydrogenase (LDH) leakage assay. Cell apoptosis, ROS accumulation, and mitochondrial membrane potential (MMP) were assessed by flow cytometry. Cytosolic translocation of mitochondrial cytochrome c and Bcl-2 family proteins were determined by Western blot. Caspase-3 and caspase-9 activities were determined by the assay kit. Results. GS-Rb1 significantly reduced cell death and LDH leakage induced by H/I. It also reduced H/I induced NRCMs apoptosis induced by H/I, in accordance with a minimal reactive oxygen species (ROS) burst. Moreover, GS-Rb1 markedly decreased the translocation of cytochrome c from the mitochondria to the cytosol, increased the Bcl-2/ Bax ratio, and preserved mitochondrial transmembrane potential (ΔΨm). Its administration also inhibited activities of caspase-9 and caspase-3. Conclusion. Administration of GS-Rb1 during H/I in vitro is involved in cardioprotection by inhibiting apoptosis, which may be due to inhibition of the mitochondrial apoptotic pathway. © 2014 Xu Yan et al. Source

Yan X.,Peking University | Xue J.,Capital Medical University | Wu H.,Peking University | Wang S.,Beijing Institute of Radiation Medicine | And 4 more authors.
Evidence-based Complementary and Alternative Medicine | Year: 2015

Ginsenoside (GS-Rb1) is one of the most important active compounds of ginseng, with extensive evidence of its cardioprotective properties. However, the miRNA mediated mechanism of GS-Rb1 on cardiomyocytes remains unclear. Here, the roles of miRNAs in cardioprotective activity of GS-Rb1 were investigated in hypoxic- and ischemic-damaged cardiomyocytes. Neonatal rat cardiomyocytes (NRCMs) were first isolated, cultured, and then incubated with or without GS-Rb1 (2.5-40 M) in vitro under conditions of hypoxia and ischemia. Cell growth, proliferation, and apoptosis were detected by MTT and flow cytometry. Expressions of various microRNAs were analyzed by real-time PCR. Compared with that of the control group, GS-Rb1 significantly decreased cell death in a dose-dependent manner and expressions of mir-1, mir-29a, and mir-208 obviously increased in the experimental model groups. In contrast, expressions of mir-21 and mir-320 were significantly downregulated and GS-Rb1 could reverse the differences in a certain extent. The miRNAs might be involved in the protective effect of GS-Rb1 on the hypoxia/ischemia injuries in cardiomyocytes. The effect might be based on the upregulation of mir-1, mir-29a, and mir-208 and downregulation of mir-21 and mir-320. This might provide us a new target to explore the novel strategy for ischemic cardioprotection. © 2015 Xu Yan et al. Source

Wu D.,Beijing Hospital of Integrated Traditional Chinese and Western Medicine | Jiang L.,Beijing Hospital of Integrated Traditional Chinese and Western Medicine | Wu H.,Beijing Hospital of Integrated Traditional Chinese and Western Medicine | Wang S.,Beijing Institute of Radiation Medicine | And 5 more authors.
Evidence-based Complementary and Alternative Medicine | Year: 2013

Background. Licorice has long been used to treat many ailments including cardiovascular disorders in China. Recent studies have shown that the cardiac actions of licorice can be attributed to its active component, glycyrrhetinic acid (GA). However, the mechanism of action remains poorly understood. Aim. The effects of GA on the delayed rectifier potassium current (IK), the rapidly activating (IKr) and slowly activating (IKs) components of IK, and the HERG K+ channel expressed in HEK-293 cells were investigated. Materials and Methods. Single ventricular myocytes were isolated from guinea pig myocardium using enzymolysis. The wild type HERG gene was stably expressed in HEK293 cells. Whole-cell patch clamping was used to record IK (IKr, IKs) and the HERG K+ current. Results. GA (1, 5, and 10 M) inhibited IK (IKr, IKs) and the HERG K+ current in a concentration-dependent manner. Conclusion. GA significantly inhibited the potassium currents in a dose- and voltage-dependent manner, suggesting that it exerts its antiarrhythmic action through the prolongation of APD and ERP owing to the inhibition of IK (IKr, IKs) and HERG K+ channel. © 2013 Delin Wu et al. Source

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