Bone marrow mesenchymal stem cell transplantation combined with perindopril treatment attenuates infarction remodelling in a rat model of acute myocardial infarction

Objective: This study was performed to evaluate whether implantation of mesenchymal stem cell (MSC) would reduce left ventricular remodelling from the molecular mechanisms compared with angiotensin-converting enzyme inhibitors (ACEIs) perindopril into ischemic myocardium after acute myocardial infarction. Methods: Forty rats were divided into four groups: control, MSC, ACEI, MSC+ACEI groups. Bone marrow stem cell derived rat was injected immediately into a zone made ischemic by coronary artery ligation in MSC group and MSC+ACEI group. Phosphate-buffered saline (PBS) was injected into control group. Perindopril was administered p.o. to ACEI group and MSC+ACEI group. Six weeks after implantation, the rats were killed and heart sample was collected. Fibrillar collagen was observed by meliorative Masson’s trichome stain. Western Blotting was employed to evaluate the protein expression of matrix metalloproteinase (MMP)-2, matrix metalloproteinase (MMP)-9 in infarction zone. The transcriptional level of MMP2, MMP9 and tissue inhibitor of matrix metalloproteinase (TIMP)-1 in infarction area was detected by reverse transcriptase PCR (RT-PCR) analysis. Results: The fibrillar collagen area, the protein expression of MMP2, MMP9 and the transcriptional level of MMP2, MMP9 mRNA in infarction zone reduced in MSC group, ACEI group, and MSC+ACEI group. No significant difference was detected in the expression of TIMP1 mRNA among the 4 groups. Conclusion: Both MSC and ACEI could reduce infarction remodelling by altering collagen metabolism.

Effect of transplantation of bone marrow stem cells on myocardial infarction size in a rabbit model

BACKGROUND:Intravenous transplantation has been regarded as a most safe method in stem cell therapies.There is evidence showing the homing of bone marrow stem cells(BMSCs) into the injured sites,and thus these cells can be used in the treatment of acute myocardial infarction(Ml).This study aimed to investigate the effect of intravenous and epicardial transplantion of BMSCs on myocardial infarction size in a rabbit model.METHODS:A total of 60 New Zealand rabbits were randomly divided into three groups:control group,epicardium group(group Ⅰ) and ear vein group(group Ⅱ).The BMSCs were collected from the tibial plateau in group Ⅰ and group Ⅱ,cultured and labeled.In the three groups,rabbits underwent thoracotomy and ligation of the middle left anterior descending artery.The elevation of ST segment>0.2 mV lasting for 30 minutes on the lead Ⅱ and Ⅲ of electrocardiogram suggested successful introduction of myocardial infarction.Two weeks after myocardial infarction,rabbits in group Ⅰ were treated with autogenous BMSCs at the infarct region and those in group Ⅱ received intravenous transplantation of BMSCs.In the control group,rabbits were treated with PBS following thoracotomy.Four weeks after myocardial infarction,the heart was collected from all rabbits and the infarct size was calculated.The heart was cut into sections followed by HE staining and calculation of infarct size with an image system.RESULTS:In groups Ⅰ and Ⅱ,the infarct size was significantly reduced after transplantation with BMSCs when compared with the control group(P<0.05).However,there was no significant difference in the infarct size between groups Ⅰ and Ⅱ(P>0.05).CONCLUSION:Transplantation of BMSCs has therapeutic effect on Ml.Moreover,epicardial and intravenous transplantation of BMSCs has comparable therapeutic efficacy on myocardial infarction.

Experimental study of qishen yiqi drop pill combined with bone marrow mesenchymal stem cell transplantation on angiogenesis and cardiac function in mice with myocardial infarction

Objective:To investigate the effects ofQishengyiqi drop pill combined with bone marrow mesenchymal stem cell transplantation on angiogenesis and cardiac function in mice after myocardial infarction through in vitro cell molecular biology experiments.Methods:The animals used in this experiment were male mice with eGFP+/-.Sixty mice were randomly divided into three groups(n=20):myocardial infarction group(MI+PBS),myocardial infarction+mesenchyme plasma stem cell transplantation group(MI+MSCs)and myocardial infarction+Qishenyiqi drip pill combined with mesenchymal stem cell transplantation group(MI+MSCs+QSYQ).Qishenyiqi dripping pills were prepared into a medicinal solution with a concentration of 3.9 mg/mL with distilled water.The MI+MSCs+QSYQ group was orally administered with 0.1 mL/kg/day,and the other two groups were orally administered with an equal amount of normal saline.Mice in each group were adaptively fed continuously for 2 weeks,and the myocardial infarction model was established by ligation of the anterior descending coronary artery by thoracic ligation.Twenty-four hours after the model was established,bone marrow mesenchymal stem cells were isolated from the tibia of the mice and injected intracardiacly Bone marrow-derived mesenchymal stem cells were transplanted,and multiple injections were made around the myocardial infarction area of mice.The control group was injected with the same amount of PBS.0h,3 days,7 days,and 14 days after cell transplantation,observe the stem cell morphology under a microscope;on day 7 of cell transplantation,track the expression of eGFP-positive cells with a fluorescence microscope;before modeling,14 and 21 days after cell transplantation,use Cardiac function was measured by echocardiography.After 21 days of modeling,the mice were sacrificed,and heart samples were taken.The angiogenesis of the mice was observed by immunohistochemical staining and microvascular density determination.Results:The morphological growth of transplanted stem cells was proportional to the time of cell transplantation.Compared with MI+PBS group,CD90.2 and y6A were highly expressed on the surface of bone marrow mesenchymal stem cells in MI+MSCs group and MI+MSCs+QSYQ group,while CD31 and CD117 were almost not expressed.On the 21st day after stem cell transplantation,the values of LVDd and LVSD in MI+MSCs+QSYQ group were significantly lower than those in MI+PBS group and MI+MSCs group.At the same time,LVEF and LVFS increased significantly.The results of quantitative immunohistochemical analysis showed that the angiogenesis density in the MI+MSCs+QSYQ group increased significantly,and the difference between the groups was statistically significant(P<0.05).Conclusion:Qishen Yiqi dripping pills combined with bone marrow mesenchymal stem cell transplantation can not only promote angiogenesis in mice with myocardial infarction,but also play a positive role in improving cardiac function.

Influence of Transplantation of Allogenic Bone Marrow Mononuclear Cells on the Left Ventricular Remodeling of Rat after Acute Myocardial Infarction

To probe into the influence of transplantation of allogenic bone marrow mononuclear cells （BM-MNCs） on the left ventricular remodeling of rat after acute myocardial infarction （AMI）, 60 male Wistar rats were evenly divided into three groups at random： control group 1, control group 2 and transplantation group. In control group 1, chest was opened without ligation of coronary artery; in control group 2 and transplantation group, the left anterior descending branch of coronary artery was ligated to establish AMI model. Prepared culture medium and allogenic BM-MNCs suspension were respectively implanted the surrounding area of infracted cardiac muscle via epicardium of control group 2 and transplantation group. Four weeks after the operation, the osteopontin gene （OPN mRNA, P〈0.01）, type Ⅰ collagen （P〈0.01） and angiotensin Ⅱ （AngⅡ, P〈0.01） content in the left ventricular non-infracted myocardium, and the Ang Ⅱ density in blood plasma （P〈0.05） of transplantation group and control group 2 were all significantly higher than that of control group Ⅰ. In the transplantation group, the myocardial OPN InRNA, type Ⅰ collagen and Ang Ⅱ content of non-infracted zone in left ventricle, and the Ang Ⅱ concentration in blood plasma were all significantly lower than those of control group 2 （P〈0.05 for all）. It is concluded that allogenic BM-MNCs transplantation may ease left ventricular remodeling after AMI by inhibiting the synthesis of type Ⅰ collagen in the cardiac muscle and down-regulating the expression of Ang Ⅱ and OPN gene.

VEGF-expressing Bone Marrow Mesenchymal Stem Cells Transplantation Improved Heart Function of Myocardial Infarct Rabbits

Objectives To treat myocardial infarction with MSCs transplantation combined with VEGF gene therapy in rabbits and to study its mechanisms. Methods Forty-eight rabbits were randomly divided into MI group （n=12）, MSCs group （n=12）, VEGF group （n=12）, MSCs＋VEGF group （M＋V group, n=12）. Rabbit myocardial infarction models were founded by the ligation of left anterior descending artery. 107 MSCs were injected into the infarct-zone in four sites 2 weeks later in MSCs and M＋ V group, phVEGF gene were injected in infarct-zone in VEGF group and MSCs transfected with phVEGF gene were injected in M＋V group. Heart function including LVEDP, LVSP, LVDP, -dp/dtmax, ＋dp/dtmax, were measured in vivo. The hearts were harvested at 4 weeks after transplantation and sectioned for HE stain, immunohistochemical stain of BrdU and VIII factor antigen. Results The left ventricular hemodynamics parameters showed that heart function were improved more in M＋V group than MSCs group, MI group and VEGF group. The numbers of BrdU positive cells in M＋ V group（61±8）were more than in MSCs group （44±8, P 〈 0.01）. The numbers of vessels in infarcted zone were more in M＋V group （49±8） than in MSCs group （33±6, P 〈 0.01）,VEGF group（30±8, P 〈 0.01）and Mlgroup （18±4, P〈0.01）. Conclusions VEGF-expressing MSCs transplantation could improve heart function after myocardial infarction, and they were more effective than sole MSCs transplantation. Keeping more MSCs survival and ameliorating the blood supply of infarct-zone might be involved in the mechanisms.

Fifteen years of bone marrow mononuclear cell therapy in acute myocardial infarction

In spite of modern treatment, acute myocardial infarction(AMI) still carries significant morbidity and mortality worldwide. Even though standard of care therapy improves symptoms and also long-term prognosis of patients with AMI, it does not solve the critical issue, specifically the permanent damage of cardiomyocytes. As a result, a complex process occurs, namely cardiac remodeling, which leads to alterations in cardiac size, shape and function. This is what has driven the quest for unconventional therapeutic strategies aiming to regenerate the injured cardiac and vascular tissue. One of the latest breakthroughs in this regard is stem cell(SC) therapy. Based on favorable data obtained in experimental studies, therapeutic effectiveness of this innovative therapy has been investigated in clinical settings. Of various cell types used in the clinic, autologous bone marrow derived SCs were the first used to treat an AMI patient, 15 years ago. Since then, we have witnessed an increasing body of data as regards this cutting-edge therapy. Although feasibility and safety of SC transplant have been clearly proved, it's efficacy is still under dispute. Conducted studies and meta-analysis reported conflicting results, but there is hope for conclusive answer to be provided by the largest ongoing trial designed to demonstrate whether this treatment saves lives. In the meantime, strategies to enhance the SCs regenerative potential have been applied and/or suggested, position papers and recommendations have been published. But what have we learned so far and how can we properly use the knowledge gained? This review will analytically discuss each of the above topics, summarizing the current state of knowledge in the field.

Human bone marrow-derived mesenchymal stem cells transplanted into damaged rabbit heart to improve heart function

Objective: The present study was designed to test whether transplantation of human bone marrow-derived mesen- chymal stem cells (hMSCs) in New Zealand rabbits with myocardial infarction can improve heart function; and whether engrafted donor cells can survive and transdifferentiated into cardiomyocytes. Methods: Twenty milliliters bone marrow was obtained from healthy men by bone biopsy. A gradient centrifugation method was used to separate bone marrow cells (BMCs) and red blood cells. BMCs were incubated for 48 h and then washed with phosphate-buffered saline (PBS). The culture medium was changed twice a week for 28 d. Finally, hematopoietic cells were washed away to leave only MSCs. Human MSCs (hMSCs) were premarked by BrdU 72 h before the transplantation. Thirty-four New Zealand rabbits were randomly divided into myocardial infarction (MI) control group and cell treated group, which received hMSCs (MI+MSCs) through intramyocardial injection, while the control group received the same volume of PBS. Myocardial infarction was induced by ligation of the left coronary artery. Cell treated rabbits were treated with 5×106 MSCs transplanted into the infarcted region after ligation of the coronary artery for 1 h, and the control group received the same volume of PBS. Cyclosporin A (oral solution; 10 mg/kg) was provided alone, 24 h before surgery and once a day after MI for 4 weeks. Echocardiography was measured in each group before the surgery and 4 weeks after the surgery to test heart function change. The hearts were harvested for HE staining and immunohistochemical studies after MI and cell transplantation for 4 weeks. Results: Our data showed that cardiac function was significantly improved by hMSC transplan- tation in rabbit infarcted hearts 4 weeks after MI (ejection fraction: 0.695±0.038 in the cell treated group (n=12) versus 0.554±0.065 in the control group (n=13) (P<0.05). Surviving hMSCs were identified by BrdU positive spots in infarcted region and transdifferentiated into cardiomyocytes characterized with a positive cardiac phenotype: troponin I. Conclusion: Transplan- tation of hMSCs could transdifferentiate into cardiomyocytes and regenerate vascular structures, contributing to functional im- provement.

Allograftic bone marrow-derived mesenchymal stem cells transplanted into heart infarcted model of rabbit to renovate infarcted heart

Objective: To investigate the directed transplantation of allograftic bone marrow-derived mesenchymal stem cells (MSCs) in myocardial infarcted (MI) model rabbits. Materials and Methods: Rabbits were divided into 3 groups, heart infarcted model with MSCs transplanted treatment (MSCs group, n=12), heart infarcted model with PBS injection (control group, n=20), sham operation with PBS injection (sham group, n=17). MSCs labelled by BrdUrd were injected into the MI area of the MSCs group. The same volume of PBS was injected into the MI area of the control group and sham group. The mortality, LVIDd, LVIDs and LVEF of the two groups were compared 4 weeks later. Tropomyosin inhibitory component (Tn I) and BrdUrd immunohistochemistry identified the engrafted cells 4 weeks after transplantation. Result: The mortality of the MSCs group was 16.7% (2/12), and remarkably lower than the control group's mortality [35% (7/20) (P<0.05)]. Among the animals that survived for 4 weeks, the LVIDd and LVIDs of the MSCs group after operation were 1.17±0.21 cm and 0.74±0.13 cm, and remarkably lower than those of the model group, which were 1.64±0.14 cm and 1.19±0.12 cm (P<0.05); the LVEF of the MSCs group after operation was 63±6%, and remarkably higher than that of the model group, which was 53±6% (P<0.05). Among the 10 cases of animals that survived for 4 weeks in the MSCs group, in 8 cases (80%), the transplanted cells survived in the non MI, MI region and its periphery, and even farther away; part of them differentiated into cardiomyocytes; in 7 cases (70%), the transplanted cells participated in the formation of blood vessel tissue in the MI region. Conclusion: Transplanted allograftic MSCs can survive and differentiate into cardiomyocytes, form the blood vessels in the MI region. MSCs transplantation could improve the heart function after MI.

Therapeutic and regenerative potential of different sources of mesenchymal stem cells for cardiovascular diseases

Mesenchymalstemcells(MSCs)areidealcandidatesfortreatingmanycardiovasculardiseases.MSCscanmodify the internal cardiac microenvironment to facilitate their immunomodulatory and differentiation abilities,which are essential to restore heart function.MSCs can be easily isolated from different sources,including bone marrow,adipose tissues,umbilical cord,and dental pulp.MSCs from various sources differ in their regenerative and therapeutic abilities for cardiovascular disorders.In this review,we will summarize the therapeutic potential of each MSC source for heart diseases and highlight the possible molecular mechanisms of each source to restore cardiac function.

Improvement of cardiac function after transplantation of autologous bone marrow mesenchymal stem cells in patients with acute myocardial infarction

Background The infarct size determines the long-term prognosis of patients with acute myocardial infarction (AMI). There is a growing interest in repairing scar area by transplanting bone marrow stem cells. However, effectiveness of intracoronary injection of bone marrow mesenchymal stem cells (BMSCs) in patients with AMI still remains unclear.Methods Sixty-nine patients with AMI after percutaneous coronary intervention (PCI) were randomly divided into intracoronary injection of BMSCs (n=34) and saline (control group, n=35) groups. Serial single positron emission computer tomography (SPECT), cardiac echo and cardiac electromechanical mapping were done at the designed time intervals until six months after transplantation of BMSCs or injection of saline. Results The proportion with functional defect decreased significantly in the BMSCs patients after three months [(13±5)%] compared with that pre-transplantation [(32±11)%] and the control group [(28±10)%] at three month follow-up (P<0.05, respectively). Wall movement velocity over the infracted region increased significantly in the BMSCs group [(4.2±2.5) cm/s vs (2.2±1.3) cm/s, P<0.05], but not in the control group [(2.2±1.5) cm/s vs (2.7±1.7) cm/s, P>0.05]. Left ventricular ejection fraction (LVEF) three months after transplantation in BMSCs group increased significantly compared with that pre-implantation and with that of the control group at three months post-injection [(67±11)% vs (49±9)% and (53±8)%, P<0.05 respectively]. SPECT scan results showed that perfusion defect was improved significantly in BMSCs group at three-month follow-up compared with that in the control group [(134±66)cm2 vs (185±87)cm2, P<0.01]. At the same time, left ventricular end-diastolic volume [(136±31) ml vs (162±27) ml, P<0.05] and end-systolic volume [(63±20) ml vs (88±19) ml, P<0.05] decreased synchronously. The ratio of end-systolic pressure to end-systolic volume [P_ syst/ESV, (2.84±1.30) mmHg/ml vs (1.72±1.23) mmHg/ml, P<0.05] increased significantly. Cardiac electromechnical mapping demonstrated significant improvement at three months after implantation of BMSCs compared with that pre-injection in both cardiac mechanical capability as left line local shorting [LLS, (11.29±1.64)% vs (7.32± 1.86)%, P<0.05] and electrical property as left ventricular endocardial unipolar voltage [UV, (10.38±1.12) mV vs (7.61±1.09) mV, P<0.01]; perfusion defect decreased from (36.2±6.2) % to (20.3±5.31)% (P<0.01). Twenty-four-hour electrocardiographic monitoring demonstrated no arrhythmias occurred at three-months follow-up.Conclusions The transplantation of BMSCs might improve the cardiac function and it is safe and feasible with no deaths or malignant arrhythmias.

Timing of transplantation of autologous bone marrow derived mesenchymal stem cells for treating myocardial infarction

It is still unclear whether the timing of intracoronary stem cell therapy affects the therapeutic response in patients with myocardial infarction.The natural course of healing the infarction and the presence of putative homing signals within the damaged myocardium appear to favor cell engraftment during the transendothelial passage in the early days after reperfusion.However,the adverse inflammatory environment,with its high oxidative stress,might be deleterious if cells are administered too early after reperfusion.Here we highlight several aspects of the timing of intracoronary stem cell therapy.Our results showed that transplantation of bone marrow mesenchymal stem cells at 2 4 weeks after myocardial infarction is more favorable for reduction of the scar area,inhibition of left ventricular remodeling,and recovery of heart function.Coronary injection of autologous bone marrow mesenchymal stem cells at 2 4 weeks after acute myocardial infarction is safe and does not increase the incidence of complications.

Recent advances in the diagnosis and treatment of acute myocardial infarction

The Third Universal Definition of Myocardial Infarction(MI) requires cardiac myocyte necrosis with an increase and/or a decrease in a patient's plasma of cardiac troponin(cT n) with at least one cT n measurement greater than the 99 th percentile of the upper normal reference limit during:(1) symptoms of myocardialischemia;(2) new significant electrocardiogram(ECG) ST-segment/T-wave changes or left bundle branch block;(3) the development of pathological ECG Q waves;(4) new loss of viable myocardium or regional wall motion abnormality identified by an imaging procedure; or(5) identification of intracoronary thrombus by angiography or autopsy.Myocardial infarction,when diagnosed,is now classified into five types.Detection of a rise and a fall of troponin are essential to the diagnosis of acute MI.However,high sensitivity troponin assays can increase the sensitivity but decrease the specificity of MI diagnosis.The ECG remains a cornerstone in the diagnosis of MI and should be frequently repeated,especially if the initial ECG is not diagnostic of MI.There have been significant advances in adjunctive pharmacotherapy,procedural techniques and stent technology in the treatment of patients with MIs.The routine use of antiplatelet agents such as clopidogrel,prasugrel or ticagrelor,in addition to aspirin,reduces patient morbidity and mortality.Percutaneous coronary intervention(PCI) in a timely manner is the primary treatment of patients with acute ST segment elevation MI.Drug eluting coronary stents are safe and beneficial with primary coronary intervention.Treatment with direct thrombin inhibitors during PCI is non-inferior to unfractionated heparin and glycoprotein Ⅱb/Ⅲa receptor antagonists and is associated with a significant reduction in bleeding.The intra-coronary use of a glycoprotein Ⅱb/Ⅲa antagonist can reduce infarct size.Pre- and post-conditioning techniques can provide additional cardioprotection.However,the incidence and mortality due to MI continues to be high despite all these recent advances.The initial ten year experience with autologous human bone marrow mononuclear cells(BMCs) in patients with MI showed modest but significant increases in left ventricular(LV) ejection fraction,decreases in LV endsystolic volume and reductions in MI size.These studies established that the intramyocardial or intracoronary administration of stem cells is safe.However,many of these studies consisted of small numbers of patients who were not randomized to BMCs or placebo.The recent LateT ime,Time,and Swiss Multicenter Trials in patientswith MI did not demonstrate significant improvement in patient LV ejection fraction with BMCs in comparison with placebo.Possible explanations include the early use of PCI in these patients,heterogeneous BMC populations which died prematurely from patients with chronic ischemic disease,red blood cell contamination which decreases BMC renewal,and heparin which decreases BMC migration.In contrast,cardiac stem cells from the right atrial appendage and ventricular septum and apex in the SCIPIO and CADUCEUS Trials appear to reduce patient MI size and increase viable myocardium.Additional clinical studies with cardiac stem cells are in progress.

Granulocyte-macrophage colony stimulating factor improves cardiac function in rabbits following myocardial infarction

Objective: To investigate the therapeutic potency of recombinant human Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) in a rabbit myocardial infarction model. Methods: A myocardial infarction was created by the ligation of the major ventricular branch of the left coronary artery in rabbits. After myocardial infarction, the animals were randomly assigned to GM-CSF treatment group, untreated groups and sham-operated group. The rabbits of the treated group were injected into GM-CSF by subcutaneous administration, 10 μg/kg/day, once a day for 5 days. The untreated and sham-operated group received a equal saline in the same manner as treated group. Six weeks later echocardiography and haemodynamic assessment were undertaken to assesse cardiac function. The size of the infarct region of the heart were also studied. Results: The untreated group exhibited significant higher left ventricle end-diastolic pressure, higher central venous pressure, and with significant lower mean blood pressure, lower peak first derivative of left ventricle pressure (dP/dt) than the sham group. Also, Rabbits in untreated group display significant systolic dysfunction shown by the decreased ejection fraction, diastolic dysfunction shown by increasing in the ratio of E wave to A wave (E/A), and display left ventricle enlargement. However, GS-CSF singnificantly prevented heart dysfunction, left ventricle enlargement, and reduced infarct size in treatment group. Conclusion: Administration GM-CSF after cardiac infarction can improve heart function. These findings indicate the technique may be a novel and simple therapeutic method for ischemic myocardium.

运动预处理联合骨髓间充质干细胞移植治疗大鼠心肌梗死

背景:干细胞疗法在改善心肌梗死后心脏重构方面具有广阔前景,但心肌微环境改变影响干细胞疗效。运动预处理类似于缺血预处理,能够对心肌产生保护作用。然而,运动预处理与干细胞移植联合作用的效果与机制鲜有关注。目的:观察运动预处理对心肌梗死大鼠骨髓间充质干细胞移植效果的影响,探讨局部炎症微环境在其中的作用机制。方法:80只雌性SD大鼠随机分为假手术组、模型组、移植组和联合组,每组20只。利用结扎冠状动脉左前降支的方法制作心肌梗死大鼠模型,假手术组仅穿线不结扎。移植组和联合组造模后于心肌内注射雄性大鼠来源骨髓间充质干细胞,此外,联合组在造模前还需进行8周跑台运动(即运动预处理)。干细胞移植后4周,采用递增负荷运动力竭实验测定运动能力,超声心动术测定心脏结构与功能,压力容积导管法检测左心室血液动力学,原位染色法进行心肌组织病理学观察并获取心肌胶原容积分数。干细胞移植后1,7 d和4周,采用定量反转录聚合酶链反应检测左心室促炎症因子(白细胞介素1β、白细胞介素6、肿瘤坏死因子α)、抗炎症因子(白细胞介素10)、Y染色体性别决定区和胚胎基因(心房钠尿肽、脑钠肽、β-肌球蛋白重链)m RNA表达量。结果与结论:(1)干细胞移植后4周:与假手术组比较,模型组运动能力、左心室射血分数降低(P <0.05);心肌梗死面积、心肌细胞横截面积、胶原容积分数增加(P <0.05);胚胎基因以及促炎因子m RNA表达量上调(P <0.05),白细胞介素10 m RNA表达量下调(P <0.05)。与模型组比较,移植组运动能力、左心室射血分数增加(P <0.05);心肌梗死面积、心肌细胞横截面积、胶原容积分数下降(P <0.05);胚胎基因以及促炎因子m RNA表达量下调(P <0.05),白细胞介素10 m RNA表达量无显著性变化(P> 0.05)。与移植组比较,联合组上述各指标均进一步改善(P<0.05)。(2)干细胞移植后1,7d:与移植组比较,联合组Y染色体性别决定区m RNA表达量升高(P<0.05)。(3)相关分析显示,白细胞介素1β、白细胞介素6(除移植后1 d)、肿瘤坏死因子α与Y染色体性别决定区m RNA表达量呈负相关(P <0.05),白细胞介素10与Y染色体性别决定区m RNA表达量呈正相关(P <0.05)。结果表明:运动预处理能够增强骨髓间充质干细胞移植治疗心肌梗死大鼠的效果,表现为心脏重构得到抑制、心功能进一步提升,其机制与心肌炎症微环境改善促进骨髓间充质干细胞滞留和存活有关。

骨髓间充质干细胞移植治疗大鼠心肌梗死:急性和慢性运动的影响

背景:干细胞移植对治疗心肌梗死具有可观的治疗前景,但移植细胞向心脏归巢效率及在心脏内的滞留率和存活率较低限制了干细胞疗效。运动疗法是心肌梗死患者心脏康复的重要有机组成部分,然而运动在干细胞移植治疗心肌梗死中的作用尚未明确。目的:探讨运动(包括急性和慢性运动)对骨髓间充质干细胞移植治疗大鼠心肌梗死的影响。方法:取80只雌性SD大鼠,采用随机数字表法分为假手术组、模型组、移植组或联合组,每组20只。模型组、移植组或联合组大鼠通过冠状动脉结扎术制作心肌梗死模型,造模24 h后,联合组进行8周有氧运动(慢性运动,30 min/d,每周运动5 d),于首次运动(急性运动)后5 min内,移植组和联合组尾静脉输注绿色荧光蛋白标记的SD大鼠骨髓间充质干细胞,首次运动后24 h取部分大鼠,检测大鼠心肌内移植的干细胞存活率、Y染色体性别决定区mRNA表达、归巢因子蛋白表达以及氧化应激和炎症反应参数;末次运动后72 h取剩余大鼠,检测心脏结构与功能、心肌组织学变化和Ki67^(+)细胞数量。结果与结论:(1)急性运动后:与假手术组比较,模型组心肌活性氧、丙二醛、肿瘤坏死因子α和白细胞介素1β水平升高(P <0.05),超氧化物歧化酶活性降低(P <0.05);与模型组比较,移植组和联合组活性氧、丙二醛水平及肿瘤坏死因子α和白细胞介素1β蛋白表达降低(P <0.05),超氧化物歧化酶活性及基质细胞衍生因子1α、CXC趋化因子受体4蛋白表达升高(P <0.05);与移植组比较,联合组活性氧、丙二醛水平及肿瘤坏死因子α和白细胞介素1β蛋白表达降低(P <0.05),干细胞存活率、Y染色体性别决定区mRNA表达、超氧化物歧化酶活性及基质细胞衍生因子1α和CXC趋化因子受体4蛋白表达升高(P <0.05)。(2)慢性运动后:与假手术组比较,模型组心肌细胞横截面积、胶原含量增加(P <0.05),左心室射血分数、左心室短轴缩短率下降(P <0.05);与模型组比较,移植组心肌细胞横截面积与胶原含量降低(P <0.05),Ki67+细胞升高(P <0.05);与移植组比较,联合组胶原含量降低(P <0.05),心肌细胞横截面积、左心室射血分数、左心室短轴缩短率、Ki67+细胞升高(P <0.05)。(3)急性运动通过促进干细胞归巢、改善心肌微环境提高外源性干细胞存活率,慢性运动可刺激干细胞移植后心肌细胞增殖、抑制心脏重塑并增强心功能,提示运动有助于优化大鼠心肌梗死后干细胞移植疗效。

Mechanisms of improvement of left ventricle remodeling by transplanting two kinds of autologous bone marrow stem cells in pigs

Background The necrosis of a large number of myocardial cells after acute myocardial infarction （AMI） results in a decrease of cardiac function and ventricle remodeling. Stem cell transplantation could improve cardiac function after AMI, but the involving mechanisms have not been completely understood. The present study aimed to investigate the effects of transplantation of autologous bone marrow mononuclear cells （BM-MNC） and mesenchymal stem cells （MSCs） via the coronary artery on the ventricle remodeling after AMI as well as the mechanisms of the effects of transplantation of different stem cells on ventricle remodeling. Methods A total of 36 male pigs were enrolled in this study, which were divided into 4 groups： control group, simple infarct model group, BM-MNC transplantation group, and MSCs transplantation group. At 90 minutes when a miniature porcine model with AMI was established, transplantation of autologous BM-MNC （（4.7±1.7）×10^7） and MSCs （（6.2±1.6）×10^5） was performed in the coronary artery via a catheter. Ultrasound, electron microscope, immunohistochemical examination and real time reverse transcriptase-pelymerase chain reaction were used respectively to observe cardiac functions, counts of blood vessels of cardiac muscle, cardiac muscle nuclear factor （NF）-κB, myocardial cell apoptosis, and the expression of the mRNA of vascular endothelial growth factor （VEGF） and basic fibroblast growth factor （bFGF） in cardiac muscles. Multivariate Logistic regression was used to analyze the correlation factors of left ventricular end-diastolic diameter （EDD）. Results The number of blood vessels in the infarct zone and around its border in the BM-MNC transplantation group was more than those in the infarct model group and MSCs group （P=0.0001） and there was less myocardial cell apoptosis in the stem cell transplantation group than that in the infarct model group （all P 〈0.01）. The positive rate of NF-κB in the stem cell transplantation group was lower than that in the infarct model group （P=0.001）. The gene expression of VEGF in the infarct border zone of the BM-MNC group was higher than that in the MSCs group （P=0.0001）. The gene expression of bFGF in the infarct border zone in the MSCs transplantation group was higher than that in the infarct model group and the BM-MNC group （P=-0.0001）. Left ventricular ejection fraction was inversely proportional to the apoptotic rate of myocardial cells and cardiac muscle NF-κB but positively correlated with the number of blood vessels and the expression of VEGF and bFGF in the infarct zone and infarct border zone. The Multivariate Logistic regression analysis on the factors influencing the left ventricular end-diastolic diameter after stem cell transplantation showed that the expression of VEGF mRNA in the cardiac muscles in the infarct zone, the number of apoptotic myocardial cells and the expression of NF-κB in the infarct border zone were independent factors for predicting the inhibitory effect on the dilation of left ventricular EDD after stem cell transplantation. Conclusions Transplantation of autologous BM-MNC and MSCs in pigs can improve the condition of left ventricular remodeling and recover the cardiac functions after AMI. The improvement of cardiac functions is related to the increase of blood vessels, the increased expression of VEGF and bFGF, the reduction of myocardial cell apoptosis, and the decrease of NF-κB level in cardiac muscle tissues after stem cell transplantation.

有氧运动预适应改善骨髓间充质干细胞治疗急性心肌梗死的效果

背景:干细胞疗法是急性心肌梗死后恢复受损心肌组织的替代治疗策略,运动预适应可诱导机体产生内源性心脏保护效应,然而两者联合应用的疗效及机制尚不清楚。目的:探讨运动预适应联合骨髓间充质干细胞对急性心肌梗死大鼠治疗效果的影响及其可能机制。方法:70只雄性SD大鼠随机分为假手术组、模型组、干细胞治疗组、运动预适应组和联合干预组。运动预适应组和联合干预组于造模前进行8周跑台有氧运动,然后通过结扎冠状动脉前降支制作急性心肌梗死模型,干细胞治疗组和联合干预组于造模后隔天尾静脉注射骨髓间充质干细胞(1×10^(9)L^(-1),1 mL),治疗4周后,利用递增负荷跑台运动实验评估运动能力,超声心动图检测心脏结构与功能;分离左心室,2,3,5-氯化三苯基四氮唑染色评估心肌梗死面积,Masson染色检测胶原容积分数,CD31免疫组织化学染色检测心肌毛细血管密度,TUNEL染色检测心肌细胞凋亡情况,免疫印迹法检测基质细胞衍生因子1、CXC趋化因子受体蛋白4、肿瘤坏死因子α、白细胞介素10和血管内皮生长因子蛋白表达量。结果与结论:①干预疗效:与假手术组比较,模型组运动能力、左心室射血分数、左心室缩短分数、CD31阳性细胞率下降(P<0.05),心肌梗死面积、胶原容积分数和心肌细胞凋亡率增加(P<0.05)。与模型组比较,干细胞治疗组运动能力无显著差异(P>0.05),运动预适应组和联合干预组运动能力提高(P<0.05);干细胞治疗组、运动预适应组、联合干预组左心室射血分数、左心室缩短分数、CD31阳性细胞率升高(P<0.05),心肌梗死面积、胶原容积分数、心肌细胞凋亡率降低(P<0.05)。与干细胞治疗组比较,联合干预组运动能力、左心室射血分数、左心室缩短分数、CD31阳性细胞率增加(P<0.05),心肌梗死面积、胶原容积分数、心肌细胞凋亡率降低(P<0.05)。②蛋白表达:与假手术组比较,模型组肿瘤坏死因子α表达升高(P<0.05),白细胞介素10和血管内皮生长因子表达下降(P<0.05)。与模型组比较,干细胞治疗组和联合干预组CXC趋化因子受体蛋白4表达升高(P<0.05),干细胞治疗组、运动预适应组和联合干预组肿瘤坏死因子α表达下降(P<0.05),白细胞介素10和血管内皮生长因子表达增加(P<0.05)。与干细胞治疗组比较,联合干预组肿瘤坏死因子α表达降低(P<0.05),CXC趋化因子受体蛋白4、白细胞介素10和血管内皮生长因子表达升高(P<0.05)。结果表明:运动预适应可增强急性心肌梗死大鼠骨髓间充质干细胞治疗的效果(抑制心脏重塑、改善心功能、延缓心力衰竭进程),其机制与促进干细胞归巢、抑制炎症反应以及促进血管新生有关。

凋亡诱导因子基因敲减对骨髓间充质干细胞移植治疗心肌梗死的影响

背景:众多基础与临床试验证实:骨髓间充质干细胞移植后的低存活率严重制约着其发挥长期的治疗效果。课题组前期研究发现凋亡相关因子在骨髓间充质干细胞凋亡过程中发挥了重要作用,其中凋亡诱导因子(apoptosis-inducing factor,AIF)蛋白可能是其中一个关键因子。目的:将AIF敲减的骨髓间充质干细胞移植至小鼠梗死心肌中,验证低AIF表达骨髓间充质干细胞移植后的存活情况以及对进一步改善心功能的重要性。方法:首先,通过LV-AIF-shRNA慢病毒感染骨髓间充质干细胞下调AIF蛋白表达,应用流式细胞术及Western blot、RT-qPCR检测慢病毒的感染效率,CCK-8检测AIF敲减骨髓间充质干细胞在缺血缺氧条件下的细胞活力;然后,构建急性心肌梗死小鼠模型,分别将正常及AIF敲减的骨髓间充质干细胞移植至心肌梗死区域,免疫荧光检测AIF蛋白的表达,ELISA检测血清脑钠尿肽水平,心脏超声检测心功能,Masson染色观察心肌纤维化情况,RT-qPCR检测AIF敲减骨髓间充质干细胞移植后SRY基因表达反映细胞存活情况。结果与结论:①LV-AIF-shRNA慢病毒感染成功构建AIF基因敲减的骨髓间充质干细胞,感染效率为97.7%,且AIF表达有显著下降(P<0.001);②在缺血缺氧培养状态下,AIF基因敲减骨髓间充质干细胞较正常骨髓间充质干细胞的细胞活力显著增加;③与移植正常骨髓间充质干细胞相比,AIF基因敲减骨髓间充质干细胞移植后在梗死心肌中的存活数目显著升高至3.71倍(P<0.001),并且显著减少了梗死区域AIF蛋白表达、心肌纤维化程度;④与移植正常骨髓间充质干细胞相比,AIF基因敲减骨髓间充质干细胞移植后血清脑钠尿肽水平显著降低(P<0.05),左室射血分数、左室缩短分数均有显著改善(P<0.05);⑤结果表明:AIF基因敲减可通过增强骨髓间充质干细胞移植后的细胞活力、增加骨髓间充质干细胞在供体内的存活从而减少心肌纤维化,改善急性心肌梗死后心功能。

透明质酸水凝胶包裹骨髓间充质干细胞改善心肌梗死大鼠的心功能(Ⅲ)

背景:作者前期的研究结果显示透明质酸水凝胶包裹骨髓间充质干细胞显著改善大鼠心肌梗死后心功能。目的:探索透明质酸水凝胶及骨髓间充质干细胞促进心肌修复的分子机制。方法:分离培养雄性SD大鼠骨髓间充质干细胞,然后用透明质酸水凝胶包裹骨髓间充质干细胞在培养皿中进行体外三维培养。结扎雌性SD大鼠左冠状动脉前降支制作心肌梗死模型,1周后行超声检测,将符合条件的大鼠随机分为4组:①PBS组(n=12);②透明质酸组(n=12);③骨髓间充质干细胞组(n=15);④骨髓间充质干细胞+透明质酸组(n=15)。造模1周后将模型鼠行二次开胸,按照分组将PBS、透明质酸水凝胶、骨髓间充质干细胞、透明质酸水凝胶包裹骨髓间充质干细胞注射到梗死边缘区及梗死区。移植后1 d、1周、2周,Western blot检测梗死区域及周边的基质金属蛋白酶2、血管内皮生长因子、胸腺素β4以及c-Kit的蛋白表达水平,移植后2周免疫荧光检测移植细胞的分化情况。结果与结论:①在移植后1周时,骨髓间充质干细胞组的基质金属蛋白酶2及血管内皮生长因子蛋白表达水平明显高于其他3组(P<0.05);在移植后2周时,透明质酸组的基质金属蛋白酶2及血管内皮生长因子的表达水平明显低于其他3组(P<0.05),但骨髓间充质干细胞+透明质酸组的基质金属蛋白酶2及血管内皮生长因子表达水平与骨髓间充质干细胞组相比无差异,这可能反映了透明质酸水凝胶对骨髓间充质干细胞分泌的因子起到缓释作用以至于移植细胞的旁分泌效应得到延长,这种延长的旁分泌效应抵消了2周时透明质酸水凝胶引发的抑制效应;②与PBS组相比,透明质酸组、骨髓间充质干细胞组及骨髓间充质干细胞+透明质酸组的胸腺素β4及c-Kit表达水平明显升高(P<0.05);③移植后2周未检测到移植细胞向心肌细胞或血管分化;④提示:移植的骨髓间充质干细胞是通过旁分泌作用促进心肌修复,透明质酸水凝胶延长了移植骨髓间充质干细胞的旁分泌作用。