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<p><b>OBJECTIVE</b>To detect the role of surviving (SVV) in the protective effect of resveratrol against hypoxia/reperfusion injury (H/RI) of cardiac microvascular endothelial cells (CMECs).</p><p><b>METHODS</b>CMECs isolated from the hearts of adult rats were exposed to hypoxia (94% N₂, 5% CO₂, 1% O₂) for 2 h followed by 4 h reoxygenation (95% O₂, 5% CO₂). The cell proliferation of CMECs was measured by MTT assay and Transwell method was used to detect migration ability of CMEC, PI-AnnexinV double staining and flow cytometry technique were employed to observe the apoptotic rate of CMECs. The SVV protein expression was detected with Western blot method.</p><p><b>RESULTS</b>Compared to control group, the proliferation (0.19 ± 0.03 vs. 0.42 ± 0.07, P < 0.01) and migration ((28 ± 2)/5HPF vs. (50 ± 3)/5 HPF, P < 0.01) abilities were impaired and the apoptosis index ((19.7 ± 0.8)% vs. (5.4 ± 0.3)%, (P < 0.05) of CMEC was increased after H/RI. The proliferation (0.36 ± 0.07 vs. 0.19 ± 0.03, P < 0.05) and migration ((55 ± 3)/5HPF vs. (28 ± 2)/5HPF, P < 0.05) abilities of CMEC were significantly improved while the apoptosis index ((9.6 ± 0.7)% vs. (19.7 ± 0.8)%, P < 0.05) was significantly decreased in H/RI+resveratrol group compared to H/RI group.SVV protein expression was also upregulated in H/RI+resveratrol group compared to H/RI group (P < 0.05). To further ascertain the role of SVV in the protective effects of resveratrol, PI3K specific inhibitor LY294002 was added to H/RI+resveratrol group, the proliferation (0.25 ± 0.05 vs. 0.36 ± 0.07, P < 0.05) and migration ((34 ± 3)/5HPF vs. (55 ± 3)/5HPF, P < 0.05) abilities were significantly decreased, the apoptosis index ((16.2 ± 0.6)% vs. (9.6 ± 0.7)%, P < 0.05) was increased and the protein expression of SVV was downregulated (P < 0.05) in LY294002+H/RI+resveratrol group compared to H/RI+resveratrol group.</p><p><b>CONCLUSION</b>Resveratrol could significantly reduce H/RI induced apoptosis and attenuate H/RI induced cardiac microvascular endothelial cells dysfunction through up-regulating PI3K/Akt/SVV pathways.</p>
Subject(s)
Animals , Rats , Apoptosis , Cell Proliferation , Chromones , Endothelial Cells , Enzyme Inhibitors , Pharmacology , Heart , Hypoxia , Morpholines , Myocardium , Myocytes, Cardiac , Phosphatidylinositol 3-Kinases , Metabolism , Proto-Oncogene Proteins c-akt , Metabolism , Rats, Sprague-Dawley , Reperfusion Injury , Drug Therapy , Stilbenes , Pharmacology , Up-RegulationABSTRACT
Objective To establish and evaluate unstable atherosclerotic plaque model in abdominal aorta induced by cold stress. Methods Sixty male New Zealand white rabbits were randomly divided into three groups:cold stress group fed with high fat diet and followed by balloon induced arterial wall injury of abdominal aorta at week 2 and exposed to cold (4℃) for 1 h per day except for the first postoperative week,balloon-injury group treated by high fat diet plus balloon-injury, control group fed a normal chow without any treatment. Pathological changes of atherosclerotic plaques among these groups were evaluated at 20 weeks. Meanwhile, serum concentrations of blood lipid,oxidized low density protein(ox-LDL),hypersensitive C-reaction protein (hs-CRP)and interleukin (IL)-8 were determined. Results There was no difference in blood lipid level between cold-stress and balloon-injury groups.Serum concentrations of ox-LDL[(56.1 +14.3)mg/L vs.(42.9± 13.8)mg/L],hs-CRP[(149.1+78.3)mg/L vs. (94.5±57.3)mg/L],IL-8 [(97.6±17.9)μg/L vs.(57.5±18.3)μg/L]and macrophage infiltration[(30.9±5.6)％ vs,(18.7±4.8) ％] were significantly higher in cold stress group than in balloon-injury group (t =2.78,6.91,14.94,6.88,all P＜0.05). Higher angiogenesis rate of atherosclerotic plaque in cold-stress group (23/31,74.1％) was observed in comparison with group balloon-injury(5/25,20,0％)(x2=16.26,P＜0.05). Conclusions Establishment of rabbit unstable atherosclerotic plaque model induced by cold stress in synergy with high fat diet and balloon-injury is feasible, which is superior to conventional method through high fat diet plus balloon-injury surgery.
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Objective To investigate the effects of constant magnetic field (CMF) on proliferation, apopto-sis and nitric oxide (NO) secretion of rat bone marrow-derived endothelial progenitor cells (EPCs) intervened by C-reactive protein (CRP). Methods EPCs were isolated from rat bone marrow by density gradient centrifugation and cultured on fibronectin-coated dishes. The cells were divided into five groups, i. e., control group, CRP (12 μg/ml) group, CRP plus CMF (0.1, 0. 5, 1.0 mT) groups. Samples were collected 24 hours after incubation. Cell proliferation was measured by MTT chromatometry. Apoptosis rate was detected by flow-cytometry. NO content of culture medium was measured by nitrate reductase method. Results As compared with control group, cell prolifer-ation in CRP group reduced significantly (0. 265±0. 008 vs 0. 316±0. 011, P < 0.05), NO secretion also de-creased significantly [(22.7±4.5) μmol/L vs (37.6±3.8) μmol/L, P < 0.05], cell apoptosis rate elevated sig-nificantly [(10.8±0. 8) % vs (4.2±0.5)% ,P < 0.05]. Cell proliferation in CRP plus 0. 5 mT or 1.0 mT CMF group (0. 295±0. 009,0. 302±0. 010) were much more than those in CRP group (P<0.05), NO secretion contents [(28.3±4.9) μmol/L, (29.2±5.6) μmol/L]were also much more than those in CRP group (P < 0.05) , apopto-sis rate [(7.4±0.5)% ,(6.9±0.6)%]was significantly lower than that in CRP group (P <0.05). Conclusion CMF at intensity of 0.5 mT and 1.0 mT can antagonize the effects of CR, promote proliferation of EPCs and secretion of NO and inhibit apoptosis rate of EPCs.
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Objective To investigate the preventive effect of magnetic stent on coronary restenosis after percutaneous arterial stenting.Methods Twenty rabbits were divided randomly into 2 groups.Bare stent(BS group,n=10)or magnetic stent(MS group,n=10)wasimplanted in the left iliac artery of the rabbits of the 2 groups,respectively.Aspirin (25mg,qd )was administered orally to the rabbitsof both groups from 3 days before stenting until the rabbits were executed.Unfractionated heparin (2500u,qd) was delivered subcuta-neously after stenting for 7days.Five rabbits of each group were randomly selected to be executed at 7 or 30 days.Stmctural changesin the iniured arteries were studied by optical microscopey,transmissive electronic microscopey and immunohistochemistry.ResultsAt 7 days.more myofibroblasts were found migrating from adventitia to tunica media and intima in BS group than in MS group.insidethe media and intima,large amount of smooth muscle cells of synthetic type were observed.At 30 days after stenting,in magnetic group,most uascular smooth musele cells(SMCs)under the intima had transformed to contractile type and only little extracellular matrix(ECM)was observed around the SMCs;whereas,in BS group,the SMCs remained to be synthetic type and large amount of ECM wasobserved around the SMCs.which was composed mainly of proteoglycans and glycoproteins. Conclusions Magnetic stent caninhibit proliferation and migration of SMCs and reducing the production of ECM.and therefore,may prevent restenosis after coronarystenting.
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Objective We aimed to investigate whether magnetic stent has preventive effect on in-stent restenosis by observing expressions of matrix metalioproteinase (MMP)2,MMP9,tissue inhibitor of matrix metalloproteinase (TIMP)1 and TIMP2 after balloon angioplasty,bare and magnetic stent implantation in rabbits.Methods Rabbits underwent balloon angioplasty,bare and magnetic stent implantation in the left iliac arteries.The changes of MMPs and TIMPs were examined at various time points in the injured arteries using the methods of zymography,Western blot analysis,reverse transcription-polymerase chain reaction (RT-PCR) and morphometric analysis.Results Balloon angioplasty group (BA) and magnetic stent group (MS) showed lower intrinsic gelatinolytic activity and higher expression of TIMPs with less intimae hyperplasia;Whereas bare stent (BS) group exhibited higher intrinsic gelatinolytic activity and lower expression of TIMPs with significant intimae hyperplasia.Conclusion Magnetic stent probably has preventive effect on in-stent restenosis by changing intrinsic matrix metalloproteinases activity and expression of TIMPs.
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BACKGROUND: Vascular smooth muscle cell(VSMC) is one of the major cell components of vascular wall and its pathologic effects in atherosclerosis has been verified and recognized. How to inhibit VSMC proliferation and migration becomes one of the hotspots in the researches regarding the prevention of coronary heart disease(CHD).OBJECTIVE: To observe the impacts of diethyl-2, 6-diethyl-4-furny-1,4-dihydropyridine-3, 5-dicarboxylate(EFDP) on angiotensin Ⅱ (Ang Ⅱ)-induced VSMC proliferation.DESIGN: A randomized controlled study based on VSMC of rabbit' s thoracic aorta cultured in vitro.SETTING: Department of cardiology in a military medical university of Chinese PLA.MATERIALS: The study was conducted in the Laboratory of Cardiology of Xijing Hospital of the Fourth Military Medical University of Chinese PLA between August 2003 and June 2004. Five New Zealand rabbits were selected for the harvest of VSMC. Animal cells were randomly divided into control group, Ang Ⅱ group and Ang Ⅱ + EFDP group(EFDP group).METHODS: New Zealand rabbits were fed by high-fat food. Thoracic aorta was harvested for the separation and culture of VSMC after the injury in thoracic aorta intima by sacculus. The experiment introduced the cultured rabbit VSMC to observe the impacts of EFDP on VSMC DNA synthesis and its time effect during VSMC proliferation promoted by Ang Ⅱ by 3H-TdR method.MAIN OUTCOME MEASURES: 3H-TdR intensity of radio activity in cells of each group to display the DNA synthesis during VSMC proliferation process.RESULTS: Ang Ⅱ could promote the synthesis of rabbit VSMC DNA, which hit its peak at the 36th hour compared with that of control group(358. 00± 49.01 vs 272.42 ± 54.96, P ＜ 0. 01 ) . EFDP had significant inhibitive effects on Ang Ⅱ-induced VSMC proliferation, which also displayed a significant dose-dependent relationship, i.e. with the elevation of EFDP concentration, its inhibitive rate on VSMC proliferation also gradually increased. At the 36th hour, 78.40 μ mol/L of EFDP had more significant effect than that of 0. 08 μmol/L of EFDP(281.50 ± 15.28 vs 349. 25 ±32.10, P＜ 0. 05).CONCLUSION: EFDP can significantly inhibit Ang Ⅱ-induced rabbit VSMC proliferation with certain dose-effect dependency and time responses,which provides a theoretical gist for the primary rehabilitative prevention of atherosclerosis.
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BACKGROUND: Angiotensin Ⅱ has been found to induce atrial electrical remodeling, which can be blocked or inhibited by allicin.OBJECTIVE: To study the effects of allicin on angiotensin Ⅱ-induced calcium channel current and intracellular free calcium concentration in human atrial myocytes.DESIGN: A randomized controlled study based on human atrial myocytes freshly isolated.SETTING: Cardiology department of a military medical university of Chinese PLA.METHODS: This study was carried out from June 2003 to June 2004 in the Laboratory of Cardiology Department, Xijing Hospital, the Fourth Military Medical University of Chinese PLA. Ten patients with congenital heart disease who underwent extracorporeal circulation surgery were included in the study. Among them, there were 6 males and 4 females with the average age of 15 ± 6 years. Tissue samples were taken from their right auricle and sent to the lab, where the atrial myocytes were freshly isolated. There were four co-administration of angiotensin Ⅱ (0. 1 μmol/L)and allicin(50 μmol/L).The conventional whole-cell configuration of the patch-clamp technique was used to detect membrane electric current of Ca2 + in L type. Confocal microscope was used with Fluo-3/AM as calcium indicator to detect changes of intracellular free calcium concentration immediately and 15 minutes after drug intervention, respectively.MAIN OUTCOME MEASURES: The peak density of electric current of Ca2 + in L type and alteration of fluoresence intensity of intracellular free calcium concentration.electric current of Ca2 + in L type in human atrial myocytes was significantly increased by angiotensin Ⅱ of 0. 1 μmol/L[( - 12. 77 ± 1. 61) vs ( -5.78affect electric current of Ca2+ in L type in human atrial myocytes group, the peak density of electric current of Ca2 + in L type was significantly lower than that in angiotensin Ⅱ group[ ( - 8.75 ± 0.97) pA/pF, P ＜ 0. 05 ].in angiotensin Ⅱ group was significantly higher than that in control and allicin groups[(2 610.1±112.6, (299.2±27.3)%; 653.9±42.5, 0;simultaneously with angiotensin Ⅱ, the alteration of intracellular fluoresence intensity was much lower than that in angiotensin Ⅱ group[ ( 1284.9 ± 85.2,(96.5±8.4)%;P ＜0.05].CONCLUSION: Allicin antagonizes angiotensin Ⅱ-induced increase in the peak density of electric current of Ca2+ in L type and intracellular calcium overload, which may relieve atrial electrical remodeling.
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Objective: To observe the effect of static magnetic fields(SMF) on the proliferation of bone mesenchymal stem cells(MSC) in human. Methods: The MSC were obtained by using gradient centrifuge method, and then selected by the adhesive method. The third generation cells were irradiated by use of static magnetic fields at different intensities for 5 days(8 h/d). The method of MTT was employed to evaluate the level of proliferation. The parameters regarding the variation of the cell cycle were detected with the flow cytometry(FCM). Results: As compared to the control group, the proliferative rate of the MSC exposed to 0.05 mT SMF was significantly higher; there was no difference between the 0.10 mT group and control group; howere, cell proliferation was attenuated significantly when SMF intensity was 0.50 mT and 1.00 mT. No abnormal ploidy was found in any group. Conclusion: The effect of SMF on the proliferation of MSC is dependent on the magnetic intensity. 0.05 mT SMF can accerate the proliferation of MSC. 0.10 mT SMF have no effects on the growth of MSC. Wherease, 0.50 mT and 1.00 mT SMF can attenuate the growth of MSC.
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Objectives: To examine effects of pinacidil on intracellular free calcium concentration of cardiomyocytes during hypoxia/reoxygenation. Methods:A cell culture model of neonatal rat cardiac myocytes was used. There were three groups, including control group, hypoxia/reoxygenation group and pinacidil group. Confocal microscope was used with Fluo 3/AM as calcium indicator to detect changes of intracellular free calcium concentration. Results:The intracellular fluoresence intensity of singular cardiomyocyte in hypoxia/reoxygenation group was significantly higher than that of the controls( P
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Objective To examine effects of hydrogen peroxide on intracellular free calcium concentration(i) in cardiac myocytes and its antagonism by carvedilol. Methods A cell culture of neonatal rat cardiac myocytes was used for experimentation. They were divided into four groups, i.e. control group, hydrogen peroxide (H 2O 2) group, carvedilol group,and H 2O 2 + carvedilol group. Confocal microscope was used with Fluo-3/AM as calcium indicator to detect changes in i immediately and 15 minutes after H 2O 2 intervention, respectively. Results The intracellular fluoresence intensity of a single cardiae myocyts in the control group and carvedilol group was low. The intracellular fluoresence intensity of a single cardiac myocyte in H 2O 2 group was significantly higher than in the control group 15 minutes after intervention (P
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Objective To observe the effects of constant magnetic fields (CMF) on angiotensinⅡ (AngⅡ)-stimulated proliferation of human umbilical arterial vascular smooth muscle cells (VSMC). Methods The experimental proliferation models of cultured human umbilical arterial VSMC stimulated with AngⅡ was establishea. The VSMC were cultured under 1 and 5 mT CMF for 48 hrs. Proliferation of the VSMC was detected by MTT and 3H-TdR incorporation method (A-value and cpm-value), and cell cycle was analyzed by flow cytometry. Results The CMF of 1 and 5 mT may antagonize proliferation of VSMC stimulated with AngⅡ, and hold-back VSMC from static phase (G 0/G 1)to DNA synthetic (S) and mitotic phase (G 2/M). Conclusion The study demonstrates that CMF of 1 and 5 mT can significantly inhibit the human VSMC proliferation.
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AIM: To examine the effects of L-carnitine on apoptosis in cultured neonatal rat cardiomyocytes induced by hypoxia/reoxygenat ion and its possible mechanism. METHODS: A cell culture model of neonatal rat cardiacmyocytes wa s used. The cultured cardiomyocytes were classified into three groups: control g roup, I/R group (anoxia for 120 min, reoxygenation for 240 min) and L-carnitine group (L-carnitine, which was classified into four different concentrations, was added to the cells 2 h before anoxia). The activities of superoxide dismutase ( S OD), the content of malondialdehyde (MDA) and the apoptosis were determined by f low cytometry (FCM). RESULTS: In I/R group SOD activities were lower, and the apoptos is rate and MDA were higher than those in control group and they were statistica lly significant (P
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AIM: To examine the effects of L-carnitine on apoptosis and oxidant injury in cultured neonatal rat cardiomyocytes induced by hypoxia/reoxygenation and its possible mechanism. METHODS: The cultured cardiomyocytes were divided into three groups, control, A/R group (anoxia for 120 min, reoxygenation for 240 min) and L-carnitine treatment group, in which cells were exposed to 20 mg/L, 50 mg/L, 100 mg/L, 200 mg/L L-carnitine respectively at 2 h before anoxia. The superoxide dismutase (SOD), succinate dehydrogenase (SDH) activities and malondialdehyde (MDA) content were examined, and the apoptosis was determined by flow of cytometry (FCM). In addition, the ultrastructure was observed by transmission electron microscopy. RESULTS: In A/R group, SOD and SDH activities were lower, the apoptosis rate and MDA content were higher than those in control group (P
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AIM: To examine the effects of hydrogen peroxide on intracellular free calcium concentration([Ca~(2+)]i) in cardiomyocytes and its antagonism by taurine. METHODS: A cell culture model of neonatal rat cardiac myocytes was used. There were four groups, control group, hydrogen peroxide (H_2O_2) group, H_2O_2+taurine (simultaneously) group,and H_2O_2+taurine (in sequence) group. Confocal microscope was used with Fluo-3/AM as calcium indicator to detect changes of [Ca~(2+)]i immediately and 15 minutes after H_2O_2 intervention, respectively. RESULTS:The intracellular fluoresence intensity of singular cardiomyocyte in H_2O_2 group was significantly higher than the control group 15 minutes after intervention (P
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Objective To investigate the changes of action potential duration (APD) and transient outward K + current (I to) and inward rectifier K + current(I K1) of ventricular myocytes after 3 weeks of myocardial infarction, and to inquire into the effect of bisoprolol. Methods APD was recorded with microelectrode. Ventricular myocytes were singly isolated from rabbit heart using modified Langendoff perfusion and soaked with collagenase. I to and I K1 of single rabbit ventricular myocytes were recorded by whole-cell path-clamp technique. Results Both APD 50 and APD 90 of the cell from noninfarcted region in MI group were markedly longer than that in sham group (P
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Objective To construct a EGFP-labled recombinant plasmid of VEGF165 (vascular endothelial growth factor) gene, and to study the transfection and expression of VEGF165 eukaryotic expression plasmid in mesenchymal stem cells (MSCs). Methods pIRES2-EGFP-VEGF165 recombinant plasmid was constructed, which was then transfected into rat MSCs. ELISA and MTT were used to detect the expression level and biological activity of VEGF in the conditioned medium after transfection. Results There was a significant increase in VEGF protein in the MSCs after being transfected with pIRES2-EGFP-VEGF165. The conditioned medium after transfection showed the biological activity of stimulating the proliferation of endothelial cells. Conclusions The pIRES2-EGFP-VEGF165, a eukaryotic expression plasmid for VEGF165 gene, is constructed. High levels of VEGF protein expression can be obtained in the MSCs transfected with pIRES2-EGFP-VEGF165. The expressed protein has the biological activity of VEGF.
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Objective\ To study whether gonadotropin releasing hormone receptor (GnRHR)mRNA exist in rat submaxillary gland and it's gene sequence. Methods\ The total RNA isolated from rat submaxillary gland was amplified by RT\|PCR, the PCR products were identified by sequencing with Sanger's method. Results\ The specific amplified band of GnRHR mRNA was detected through agarose gel electrophoresis and gene sequence is identical to the sequence of GnRHR which has been reported in rat pituitary. Conclusion\ GnRHR can be produced by submaxillary and response for modulating biological function of submaxillary.\;