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AS-169 AngiotensinII Promotes Cardiomyocyte Differentiation of Rat Bone Marrow Mesenchymal Stem Cells
Wednesday, April 27 - Friday April 29, 2011 (Poster Abstract Zone) den death syndrome.12 of the rabbits recovered from ventricular fibrillation to normal rhythm when EFs were gradually lowered to 3.0 V/cm. Furthermore, Electrical stimulation for 1h at 3.5 V/cm and 4.0 or 4.5 V/cm only increased the epicardial temperature in the anelectrode by 1.05⫾0.81 0C 1.14⫾0.23 0C respectively, but having no statistical significance P⬎0.05. Additionally, after electrical stimulation for 1h at 3.5 V/cm there were only inflammatory cell infiltrate and denaturation in the myocardium. Howerever, anomalism contraction bands and focal coagulation necrosis of myocardium were still observed after electrical stimulation for 1h at 4.0 or 4.5 V/cm. Conclusion: The weak steady EFs(ⱕ3.5V/cm) failed to cause the cardiac electrical injuries obviously.
AS-168 The Study of Effect of Angiotensin II on The Biological Behavior of Vascular Smooth Muscle Cell (VSMC) in Rats. Xunming CHENG. Southwest Hospital, Chongqing, China. Background: To study the effect of Angiotensin II on the roliferation,migration and apoptosis of vascular smooth muscle cell (VSMC) in rats. Methods: The recombinant adenoviral vector, AdCMV-AT2R, containing rat AT2 receptor gene was constracted by homologous recombination, and then it was used to transfer AT2 receptor gene to rat VSMC in vitro. The expression of AT2R mRNA was detected by RT-PCR and the rate of expression in VSMC was determined by flow cytometer. Cell proliferation was determined by incorporation of bromodeoxyuridine(BrdU). The modified Boyden’s chamber method was used to test the migration of VSMC. Apoptosis was quantified by flow cytometer. Results: RT-PCR showed that the expression of AT2R mRNA increased obviously in transferred VSMC, and the peak value of expression rate was about 89.51% at 48 hours. When the expression of AT2R was at peak value, the OD value of BrdU incorporation were reduced by 51.6%(p⬍0.01), and the number of VSMC migration was also decreased by 62.2%(p⬍0.05). The ratio of apoptosis in VSMC was increased from 7.6⫾1.6% in control group to 32.1⫾5.5% in treated group. Conclusion: The results indicated that the expression of AT2R can inhibit the proliferation and migration of rat VSMC and induce its apoptosis.
AS-169 AngiotensinII Promotes Cardiomyocyte Differentiation of Rat Bone Marrow Mesenchymal Stem Cells. Yu Jie Xing, An Lin Lv, Li Wang, Xue Bo Yan. Xijing Hospital, Xi’an, China. Background: Ischemia heart disease is a major cause of morbidity and mortality in many countries, especially in developed countries. Established pharmacologic treatment can decelerate but not stop the progression of heart failure caused by ischemia heart disease once a significant part of the myocardium is lost. Currently heart transplantation is the only viable treatment option for end-stage heart failure patients. Given the persistent shortage of donor heart organs’ donation, stem cell therapy, especially bone marrow mesenchymal stem cells (BMMSCs), offers a novel therapeutic option in the treatment of ischemia heart diseases. Many studies have showed that 5-aza can induce BMMSCs to differentiate into cardiomyocytes. Our previous work have showed that angiotensin II(ang II) can induce BMMSCs into the cells with cardiac phenotype. In the present study, we induced rat BMMSCs with angiotensinII and 5-aza to investigate the effects of angiotensinII on proliferation and differentiation of rat BMMSCs induced with 5-azacytidine in vitro.
Methods: BMMSCs were isolated from bone marrow of SD mouse by density gradient centrifugation. The third passage cells were divided into four groups: angII group (0. 1 mol/L) (group A) 5-aza group (10mol/L) (group B) angII combined with 5-aza group (0.1mol/L and 10mol/L) (group C) untreated group as control. After 24h induction, the medium was changed to complete culture medium without any inductor and the cells were culture for 4 weeks. The morphological changes were observed under phase contrast microscope. The effect of angII and 5-aza on the BMMSCs proliferation was observed with methyl thiazolyl tetrazolium (MTT) assay. The cardiomyogenic cells were identified by immunofluorescence staining. The induction ratio was examined by flow cytometer. The level of cardiac troponin-I was examined by western blotting. The ultrastructures of the induced cells were viewed with a transmission electron microscope. Results: MTT assay showed that the cell proliferation in group C outweighed that of in group A or group B, but no significance existed in group A and group B. The expression of specific proteins of cardiac troponin I (cTnI) and sarcomeric a-actin in induced BMMSCs were positive. Flow cytometer showed that the induction ratio in group C was higher than that of in group A or group B. The protein levels of cTnI in group C were significantly higher than those of in control group. Transmission electron microscopy showed that the induced cells had myofilaments, Z line-like substances, desmosomes and gap junctions. Conclusion: AngiotensinII can promote the proliferation and differentiation of BMMSCs into cardiomyocyte-like cells induced with 5-azacytidine.
AS-170 A Reliable Porcine Coronary Model of Chronic Total Occlusion Using Copper Wire Stents and Levo-Poly Lactic Acid. Doo Sun Sim1, Myung Ho Jeong1, Kyoung Rae Cha2, Suk Ho Park2, Jong Oh Park2, Heung Soo Shin3, Young Joon Hong1, Youngkeun Ahn1, Robert S. Schwartz4. 1Chonnam National University Hospital, Gwangju, Korea (Republic of); 2Chonnam National University, Gwangju, Korea (Republic of); 3Hangyang University, Seoul, Korea (Republic of); 4Minneapolis Heart Institute, Minneapolis, USA. Background: Copper wire stents may provoke gradual intra-luminal occlusion through inflammatory reactions. Levo-poly lactic acid (LPLA), a bioabsorbable polymer, promotes in-vivo angiogenesis in both mouse and rabbit models and may be utilized to induce CTO in large animals. We investigated the feasibility and reliability of copper wire stents and L-PLA as a means of CTO induction in a porcine model. Methods: In 20 female swine (25-30 kg), copper wire stents were crimped on a 3.0 mm angioplasty balloon and inserted into the mid-left anterior descending coronary artery (LAD) with 1.1: 1 stent: artery ratio. In another group of 20 female swine, L-PLA was wrapped on a guidewire and pushed into the distal LAD with a 3.0 mm balloon catheter to induce embolization. Five weeks later, all pigs were euthanized after follow-up coronary angiography and the arteries were examined histologically. Results: Of 20 pigs which underwent copper stent implantation, 13 died of stent thrombosis (acute: 7, subacute: 6). Total occlusion was observed in 3 and near-total occlusion in 4. Histological studies revealed organized thrombus with fibrosis, calcification, and neovascular channels in pigs with total occlusion. The density of fibrosis was greater at the proximal and distal ends of the occlusive lesions and softer, organizing thrombus was observed in the middle, similar to CTO in humans. Of 20 pigs which underwent L-PLA embolization, 6 suffered death associated with acute myocardial infarction during the procedure or shortly after the experiment. Near total or total occlusion
The American Journal of Cardiology姞 APRIL 27–29, 2011 ANGIOPLASTY SUMMIT ABSTRACTS/Poster
53A
P O S T E R A B S T R A C T S
AS-168 The Study of Effect of Angiotensin II on The Biological Behavior of Vascular Smooth Muscle Cell (VSMC) in Rats. Xunming CHENG. Southwest Hospital, Chongqing, China. Background: To study the effect of Angiotensin II on the roliferation,migration and apoptosis of vascular smooth muscle cell (VSMC) in rats. Methods: The recombinant adenoviral vector, AdCMV-AT2R, containing rat AT2 receptor gene was constracted by homologous recombination, and then it was used to transfer AT2 receptor gene to rat VSMC in vitro. The expression of AT2R mRNA was detected by RT-PCR and the rate of expression in VSMC was determined by flow cytometer. Cell proliferation was determined by incorporation of bromodeoxyuridine(BrdU). The modified Boyden’s chamber method was used to test the migration of VSMC. Apoptosis was quantified by flow cytometer. Results: RT-PCR showed that the expression of AT2R mRNA increased obviously in transferred VSMC, and the peak value of expression rate was about 89.51% at 48 hours. When the expression of AT2R was at peak value, the OD value of BrdU incorporation were reduced by 51.6%(p⬍0.01), and the number of VSMC migration was also decreased by 62.2%(p⬍0.05). The ratio of apoptosis in VSMC was increased from 7.6⫾1.6% in control group to 32.1⫾5.5% in treated group. Conclusion: The results indicated that the expression of AT2R can inhibit the proliferation and migration of rat VSMC and induce its apoptosis.
AS-169 AngiotensinII Promotes Cardiomyocyte Differentiation of Rat Bone Marrow Mesenchymal Stem Cells. Yu Jie Xing, An Lin Lv, Li Wang, Xue Bo Yan. Xijing Hospital, Xi’an, China. Background: Ischemia heart disease is a major cause of morbidity and mortality in many countries, especially in developed countries. Established pharmacologic treatment can decelerate but not stop the progression of heart failure caused by ischemia heart disease once a significant part of the myocardium is lost. Currently heart transplantation is the only viable treatment option for end-stage heart failure patients. Given the persistent shortage of donor heart organs’ donation, stem cell therapy, especially bone marrow mesenchymal stem cells (BMMSCs), offers a novel therapeutic option in the treatment of ischemia heart diseases. Many studies have showed that 5-aza can induce BMMSCs to differentiate into cardiomyocytes. Our previous work have showed that angiotensin II(ang II) can induce BMMSCs into the cells with cardiac phenotype. In the present study, we induced rat BMMSCs with angiotensinII and 5-aza to investigate the effects of angiotensinII on proliferation and differentiation of rat BMMSCs induced with 5-azacytidine in vitro.
Methods: BMMSCs were isolated from bone marrow of SD mouse by density gradient centrifugation. The third passage cells were divided into four groups: angII group (0. 1 mol/L) (group A) 5-aza group (10mol/L) (group B) angII combined with 5-aza group (0.1mol/L and 10mol/L) (group C) untreated group as control. After 24h induction, the medium was changed to complete culture medium without any inductor and the cells were culture for 4 weeks. The morphological changes were observed under phase contrast microscope. The effect of angII and 5-aza on the BMMSCs proliferation was observed with methyl thiazolyl tetrazolium (MTT) assay. The cardiomyogenic cells were identified by immunofluorescence staining. The induction ratio was examined by flow cytometer. The level of cardiac troponin-I was examined by western blotting. The ultrastructures of the induced cells were viewed with a transmission electron microscope. Results: MTT assay showed that the cell proliferation in group C outweighed that of in group A or group B, but no significance existed in group A and group B. The expression of specific proteins of cardiac troponin I (cTnI) and sarcomeric a-actin in induced BMMSCs were positive. Flow cytometer showed that the induction ratio in group C was higher than that of in group A or group B. The protein levels of cTnI in group C were significantly higher than those of in control group. Transmission electron microscopy showed that the induced cells had myofilaments, Z line-like substances, desmosomes and gap junctions. Conclusion: AngiotensinII can promote the proliferation and differentiation of BMMSCs into cardiomyocyte-like cells induced with 5-azacytidine.
AS-170 A Reliable Porcine Coronary Model of Chronic Total Occlusion Using Copper Wire Stents and Levo-Poly Lactic Acid. Doo Sun Sim1, Myung Ho Jeong1, Kyoung Rae Cha2, Suk Ho Park2, Jong Oh Park2, Heung Soo Shin3, Young Joon Hong1, Youngkeun Ahn1, Robert S. Schwartz4. 1Chonnam National University Hospital, Gwangju, Korea (Republic of); 2Chonnam National University, Gwangju, Korea (Republic of); 3Hangyang University, Seoul, Korea (Republic of); 4Minneapolis Heart Institute, Minneapolis, USA. Background: Copper wire stents may provoke gradual intra-luminal occlusion through inflammatory reactions. Levo-poly lactic acid (LPLA), a bioabsorbable polymer, promotes in-vivo angiogenesis in both mouse and rabbit models and may be utilized to induce CTO in large animals. We investigated the feasibility and reliability of copper wire stents and L-PLA as a means of CTO induction in a porcine model. Methods: In 20 female swine (25-30 kg), copper wire stents were crimped on a 3.0 mm angioplasty balloon and inserted into the mid-left anterior descending coronary artery (LAD) with 1.1: 1 stent: artery ratio. In another group of 20 female swine, L-PLA was wrapped on a guidewire and pushed into the distal LAD with a 3.0 mm balloon catheter to induce embolization. Five weeks later, all pigs were euthanized after follow-up coronary angiography and the arteries were examined histologically. Results: Of 20 pigs which underwent copper stent implantation, 13 died of stent thrombosis (acute: 7, subacute: 6). Total occlusion was observed in 3 and near-total occlusion in 4. Histological studies revealed organized thrombus with fibrosis, calcification, and neovascular channels in pigs with total occlusion. The density of fibrosis was greater at the proximal and distal ends of the occlusive lesions and softer, organizing thrombus was observed in the middle, similar to CTO in humans. Of 20 pigs which underwent L-PLA embolization, 6 suffered death associated with acute myocardial infarction during the procedure or shortly after the experiment. Near total or total occlusion
The American Journal of Cardiology姞 APRIL 27–29, 2011 ANGIOPLASTY SUMMIT ABSTRACTS/Poster
53A
P O S T E R A B S T R A C T S