Gene expression of colony‐stimulating factors and stem cell factor after myocardial infarction in the mouse

Recent studies have suggested that cytokines such as macrophage colony‐stimulating factor (M‐CSF) might be involved in the pathogenesis of ischaemic heart disease. Macrophage colony‐stimulating factor, granulocyte‐colony stimulating factor (G‐CSF), granulocyte‐macrophage‐colony stimulating factor (GM‐CSF), stem cell factor (SCF), interleukin‐3 (IL‐3) and interleukin‐7 (IL‐7) are potent cytokines belonging to the same structual class that may affect function, growth and apoptosis both in the heart and other organs. The aims of the present study were to characterize a post‐infarction model in the mouse and to examine mRNA expression of M‐CSF, GM‐CSF, SCF, IL‐3 and IL‐7 during the development of heart failure. Myocardial infarction (MI) was induced in mice by ligation of the left coronary artery. Average infarct size was 40% and the mice developed myocardial hypertrophy and pulmonary oedema. Ribonuclease (RNAase) protection assays showed abundant cardiac expression of M‐CSF and SCF. After MI, we measured down‐regulation of cytokine mRNA expression in the heart (M‐CSF, SCF), lung (M‐CSF), liver (M‐CSF) and spleen (M‐CSF) compared with sham. Cardiac G‐CSF, GM‐CSF and IL‐7 mRNAs were not detected. In conclusion, abundant cardiac gene expression of M‐CSF and SCF was found. In our mouse model of MI, M‐CSF and SCF were down‐regulated in the heart and several other organs suggesting specific roles for these cytokines during development of ischaemic heart failure.     

干细胞生长因子和粒细胞集落刺激因子与心肌梗死大鼠体内骨髓间充质干细胞的迁移

背景：外周静脉移植间充质干细胞只有1%~5%的移植细胞能归巢到心肌梗死区域。 目的：观察干细胞生长因子、粒细胞集落刺激因子对骨髓间充质干细胞归巢的影响。 方法：采用贴壁培养法分离培养SD大鼠骨髓间充质干细胞,取传至3~5代细胞。建立SD大鼠急性心肌梗死模型,干细胞生长因子组、粒细胞集落刺激因子组、干细胞生长因子+粒细胞集落刺激因子组在骨髓间充质干细胞移植前3 d和移植后3 d单独或混合皮下注射干细胞生长因子、粒细胞集落刺激因子,骨髓间充质干细胞组不注射细胞因子。 结果与结论：荧光显微镜下观察,骨髓间充质干细胞迁移至心肌梗死组织,骨髓间充质干细胞组、干细胞生长因子组、粒细胞集落刺激因子组迁移至心肌梗死区的骨髓间充质干细胞数量没有明显的区别(P > 0.05),干细胞生长因子+粒细胞集落刺激因子组的骨髓间充质干细胞数量明显高于其他3组(P < 0.05)。免疫荧光组织化学显示,植入的部分骨髓间充质干细胞表达心肌特异蛋白cTnI。结果说明干细胞生长因子和粒细胞集落刺激因子两种细胞因子联合应用可以促进骨髓间充质干细胞归巢至心肌梗死区域,在体内微环境的诱导下,骨髓间充质干细胞能够转化为心肌样细胞。     

粒细胞集落刺激因子动员骨髓干细胞治疗大鼠急性心肌梗塞

目的:探讨G-CSF动员的骨髓来源干细胞对急性心肌梗塞动物模型的治疗作用与对缺血濒死心肌的保护作用。方法:用异丙肾上腺素(ISO)复制急性心肌梗塞大鼠动物模型,于3h后用G-CSF动员骨髓干细胞释放和迁移至心肌梗塞部位,并分别于24h、48h和2周后杀死大鼠,取出心脏,检测心肌的病理变化情况。结果:用ISO后24h对照组可见散在心肌梗塞灶,坏死区周围有多量以中性粒细胞为主的炎症细胞浸润,而治疗组大鼠心肌坏死程度较对照组轻,浸润的细胞以单个核细胞为主;48h后对照组心肌梗塞灶进一步扩大,呈散在片状分布,而治疗组心肌梗塞灶扩大不明显,呈散在灶性分布,并可见成堆或散在分布的淋巴细胞样细胞;2周后,治疗组未见明显心肌梗塞后疤痕组织,可见新生的心肌细胞生长。结论:G-CSF对缺血濒死心肌有保护作用,用G-CSF动员骨髓来源的干细胞进行"自我移植",可用于急性心肌梗塞的治疗。     

Administration of granulocyte colony-stimulating factor after myocardial infarction enhances the recruitment of hematopoietic stem cell-derived myofibroblasts and contributes to cardiac repair

The administration of granulocyte colony-stimulating factor (G-CSF) after myocardial infarction (MI) improves cardiac function and survival rates in mice. It was also reported recently that bone marrow (BM)-derived c-kit(+) cells or macrophages in the infarcted heart are associated with improvement of cardiac remodeling and function. These observations prompted us to examine whether BM-derived hematopoietic cells mobilized by G-CSF administration after MI play a beneficial role in the infarct region. A single hematopoietic stem cell from green fluorescent protein (GFP)-transgenic mice was used to reconstitute hematopoiesis in each experimental mouse. MI was then induced, and the mice received G-CSF for 10 days. In the acute phase, a number of GFP(+) cells showing the elongated morphology were found in the infarcted area. Most of these cells were positive for vimentin and alpha-smooth muscle actin but negative for CD45, indicating that they were myofibroblasts. The number of these cells was markedly enhanced by G-CSF administration, and the enhanced myofibroblast-rich repair was considered to lead to improvements of cardiac remodeling, function, and survival rate. Next, G-CSF-mobilized monocytes were harvested from the peripheral blood of GFP-transgenic mice and injected intravenously into the infarcted mice. Following this procedure, GFP(+) myofibroblasts were observed in the infarcted myocardium. These results indicate that cardiac myofibroblasts are hematopoietic in origin and could arise from monocytes/macrophages. MI leads to the recruitment of monocytes, which differentiate into myofibroblasts in the infarct region. Administration of G-CSF promotes this recruitment and enhances cardiac protection.     

大鼠急性心肌梗死后干细胞抗原-1和Nanog阳性细胞的动态变化

目的观察大鼠急性心肌梗死后心肌干细胞在梗死病程中的动态变化。方法成年SD大鼠50只,结扎冠状动脉前降支制备急性心肌梗死模型,在术前及术后1周、2周、3周和4周分别检测心功能指标:左室射血分数(LVEF)、左室短轴缩短率(LVFS)、左室舒张末期内径(LVEDD)、左室舒张末期容积(LVEDV)和左室后壁舒张末期厚度(LVPWT)。取各组大鼠新鲜心脏,石蜡切片、Masson染色,确定心肌梗死的病理变化。利用免疫组织化学技术对各组心脏切片进行免疫染色,观察干细胞抗原-1(Sca-1)、Nanog阳性心肌干细胞的动态变化。对每组切片阳性表达的细胞数进行定量分析。利用Western blotting技术观察Sca-1、Nanog的蛋白含量。结果大鼠心功能于术后1周开始降低,自第3周稳定于较低水平;Masson染色显示心肌梗死区域瘢痕组织明显,证实模型制备成功;免疫组织化学结果显示,Sca-1、Nanog阳性心肌干细胞数量在2周时上升至高峰,随后下降。结论 Sca-1、Nanog阳性心肌干细胞在心肌梗死病理演变过程中呈先上升后下降的趋势,提示心肌干细胞在心肌损伤和修复过程中发挥了重要作用。     

骨髓间充质干细胞移植心肌梗死大鼠的心功能

背景：前期研究发现移植的骨髓间充质干细胞能在受损心肌组织内存活和分化。 目的：进一步观察局部注射移植同种异体骨髓间充质干细胞对心肌梗死模型大鼠心功能的影响。 方法：体外培养的同种异体骨髓间充质干细胞达到一定数量(10⁶)后用BrdU标记。24只SD大鼠随机分为3组：正常对照组未行冠状动脉前降支结扎,取骨髓间充质干细胞约1 mL直接注射到冠状动脉前降支心肌的周围;假移植组：在冠状动脉前降支结扎后7 d,取等量DMEM培养液直接注射到梗死心肌的周围;骨髓间充质干细胞移植组：冠状动脉前降支结扎后7 d,取等量骨髓间充质干细胞直接注射到梗死心肌的周围;分别于移植前、移植后5周测定大鼠心功能。 结果与结论：①移植后5周假移植组最大左室收缩末压、左室内压最大(最小)变化速率均低于移植前(P < 0.01),而左室舒张末压高于移植前(P < 0.01);移植后5周骨髓间充质干细胞移植组最大左室收缩末压、左室内压最大(最小)变化速率高于移植前(P < 0.01),而左室舒张末压低于移植前(P < 0.01)。②移植后5周,骨髓间充质干细胞移植组大鼠的最大左室收缩末压、左室内压最大(最小)变化速率均高于假移植组(P < 0.01),而左室舒张末压明显低于假移植组(P < 0.01)。结果可见骨髓间充质干细胞移植可明显改善心肌梗死模型大鼠心功能。     

Gene expression profiling of mouse embryonic stem cell progeny differentiated by Lumelsky's protocol

Successful conversion of embryonic stem (ES) cells into insulin-producing cells has been reported by Lumelsky et al. (Science 2001;292:1389-1394); however, it remains controversial. In this study, we investigated the properties of ES cell progeny-induced differentiation according to Lumelsky's protocol by immunocytochemistry, oligonucleotide microarray and real-time RT-PCR. Insulin-positive cells were observed at stages 3, 4 and 5. Microarray analysis demonstrated upregulation and appearance of some genes involved in pancreatic development but not beta-cell-specific functional genes in cells at stage 5. Similarly, real-time RT-PCR revealed that expression of beta-cell-specific functional genes such as islet amyloid polypeptide, insulin I and II was not increased in cells at stage 5. These results suggest that terminal differentiation of ES cell progeny toward functional pancreatic beta-cell is insufficient. This study also demonstrates the usefulness of multiple time-course expression profiles for validating differentiation fates of ES cell progeny.     

裸鼠心梗模型及外周血干细胞移植模型的建立

目的：建立裸小鼠心肌梗死的模型并进行细胞移植，探讨这种免疫缺陷的心肌缺血模型在人类来源的干细胞尤其是外周血干细胞移植中的作用。方法：22只裸小鼠在辅助通气的条件下，开胸并结扎其冠状动脉前降支，以结扎即刻心电图描记的ST段是否明显抬高作为结扎成功的指标。采用经尾静脉注射及心肌局部注射2种 方法将分离的外周血干细胞导入动物体内。2－4周后处死动物并取心脏制备冰冻切片并用免疫荧光方法检测HLA（人类白细胞抗原）。结果:11只手术鼠术后病理肉眼观和显微镜检均可见心脏出现梗死区，成功率50％，并且免疫荧光发现裸小鼠心肌内有表达HLA的细胞。结论:通过建立免疫缺陷的裸小鼠心肌梗死模型，为观察人外周血干细胞移植提供了一种直接可行的方法。     

Connective tissue growth factor expression and Smad signaling during mouse heart development and myocardial infarction.

Connective tissue growth factor (CTGF) is reported to be a target gene of transforming growth factor beta (TGFbeta) and bone morphogenetic protein (BMP) in vitro. Its physiological role in angiogenesis and skeletogenesis during mouse development has been described recently. Here, we have mapped expression of CTGF mRNA during mouse heart development, postnatal adult life, and after experimental myocardial infarction. Furthermore, we investigated the relationship between CTGF and the BMP/TGFbeta signaling pathway in particular during heart development in mutant mice. Postnatally, CTGF expression in the heart became restricted to the atrium. Strikingly, 1 week after myocardial infarction, when myocytes have disappeared from the infarct zone, CTGF and TGFbeta expression as well as activated forms of TGFbeta but not BMP, Smad effector proteins are colocalized exclusively in the fibroblasts of the scar tissue, suggesting possible cooperation between CTGF and TGFbeta during the pathological fibrotic response.     

Tests for rheumatoid factor after myocardial infarction

An investigation was carried out into the occurrence of positive tests for rheumatoid factor after myocardial infarction. Fifty-five patients, 41 males and 14 females, were studied in 56 separate admissions for acute myocardial infarction. Tests for thyroid antibodies were also performed on all patients.In 16 patients a positive rheumatoid factor test was obtained in the post-infarction period on at least one occasion. The reaction was usually a weak positive one, and in most cases had disappeared on discharge from hospital. Transient false positive tests for thyroid complement-fixing antibody were obtained in seven male patients.Positive tests tended to occur in older patients, with a previous history of infarction, and usually with more severe infarcts, as judged from the maximum level of serum glutamic oxaloacetic transaminase obtained in the first 48 hours after infarction, and the occurrence of clinical cardiac failure.This is probably a relatively non-specific manifestation of tissue damage, the clinical importance of which is unknown.     

干细胞移植治疗心肌坏死的基础与临床研究

干细胞治疗心肌坏死是一种新的很有前景的治疗手段,但其机制尚不十分清楚。我国目前临床研究发现干细胞移植可以明显改善急性心肌梗死及梗死后心衰心脏功能,但由于关于干细胞移植的安全性还没有定论,因此还需慎重对待。     

同种异体骨髓间充质干细胞移植在心肌梗死后心室重建中的作用

BACKGROUND:Myocardial infarction leads to ischemic changes in the myocardium, triggering the emergence of ventricular remodeling, which is an important cause of death. Myocardial infarction is a common disease in the middle-aged and elderly population, but autologous bone marrow mesenchymal stem cells from these patients exhibit a weak ability of proliferation and differentiation. Therefore, a positive attempt of allogeneic stem cell transplantation is required in order to obtain better therapeutic outcomes. OBJECTIVE:To explore the effect of allogeneic bone marrow mesenchymal stem cells on ventricular remodeling after myocardial infarction.   METHODS:Bone marrow mesenchymal stem cells from 10 neonatal rats and 10 adult rats were isolated, cultured and identified. Another 40 rats were randomly assigned into four groups (n=10/group): model group, neonatal rat cell transplantation group, adult rat cell transplantation group, or sham group. Animal models of myocardial infarction were made in rats in the all groups except for the sham group in which the rats were given sham operation. Rats in the two cell transplantation groups were given the corresponding cell transplantation. Four weeks postoperatively, heart function of rats was detected in each group, and cardiac tissues were taken to detect changes in collagen formation and blood vessel density in the infarct area. RESULTS AND CONCLUSION:Four weeks after surgery, rats in the model group showed significant changes in cardiac function indexes as compared with the other groups (P < 0.05), while compared with the model group, these cardiac function indexes improved in both two cell transplantation groups, but there was no significant difference between the two cell transplantation groups (P > 0.05). Meanwhile, compared with the model group, significantly decreased collagen formation and increased blood vessel density were found in both two cell transplantation groups (P < 0.05). Additionally, the vascular density of the infarct area was highest in the sham group (P < 0.05). Experimental results show that both neonatal and adult rat bone marrow mesenchymal stem cell transplantation can improve cardiac function of rats, reduce the formation of collagen in the infarct area and delay ventricular remodeling after myocardial infarction.     

干细胞治疗心肌梗死的研究概况

心肌梗死引起的瘢痕形成和并发的心肌功能降低,可继而导致心室重构和心力衰竭的发生。因此,恢复受损心肌组织功能的治疗必不可少,以干细胞为基础的心肌再生与修复治疗最终能够避免心室重构的进程和心力衰竭的发生。心脏疾病的细胞治疗是一个快速发展的领域,但目前仍然存在许多难以解决的问题。     

干细胞因子和粒细胞集落刺激因子动员自身骨髓干细胞治疗缺血再灌注肾损伤

背景：骨髓干细胞可分化为肾脏组织固有细胞、修复损伤肾组织。正常情况下,外周血干细胞数目较少,骨髓干细胞动员剂可提高外周血干细胞数目。 目的：观察动员自身骨髓干细胞对缺血再灌注损伤肾脏修复作用及对缺氧诱导因子1α系统的影响,分析骨髓干细胞修复损伤肾脏的机制。 方法：SD大鼠随机分为4组。对照组不作处置;模型组制备肾缺血再灌注模型;治疗组给予缺血再灌注模型大鼠皮下注射骨髓干细胞动员剂干细胞因子200 μg/(kg•d)及粒细胞集落刺激因子50 μg/(kg•d),治疗对照组给予正常大鼠皮下注射与治疗组相同的药物,连续5 d。于术后5,10,17,24,31 d观察大鼠肾脏病理改变、骨髓干细胞表面抗原标记CD34⁺细胞表达以及缺氧诱导因子1α、血管内皮生长因子、血红素加氧酶1的表达变化。 结果与结论：①联合应用骨髓干细胞动员剂能明显增加损伤肾组织骨髓干细胞的数量,减轻肾组织损伤程度。②骨髓干细胞能促进肾组织缺氧诱导因子1α系统的表达,缺氧诱导因子1α系统及其靶基因产物血管内皮生长因子、血红素加氧酶1表达增加是骨髓干细胞促进急性肾损伤修复的可能机制之一。③骨髓干细胞动员剂对缺氧诱导因子1α系统的表达有一定的增强作用。     

脂肪间充质干细胞移植急性心肌梗死区域对心肌组织的保护作用

BACKGROUND: Adipose-derived mesenchymal stem cells have rich sources that are easily obtained, which can be used to treat acute myocardial infarction. OBJECTIVE: To investigate the therapeutic effect of adipose-derived mesenchymal stem cell transplantation on acute myocardial infarction in rats. METHODS: Rat models of acute myocardial infarction were made and subjected to adipose-derived mesenchymal stem cell transplantation in comparison with model and control (sham operation) groups. RESULTS AND CONCLUSION: Echocardiography findings showed significant improvement in the left ventricular end-systolic diameter, left ventricular end-diastolic diameter and ejection fraction in the cell transplantation group compared with the model group (P < 0.05). Hematoxylin-eosin staining showed that myocardial infarction was evident in the model group, in which, there were rarely viable myocardial tissues and few vessels in the infarcted region, but in the cell transplantation group, there were evident survived myocardial tissues and transplanted cells. The percentage of infarct size was significantly lower in the cell transplantation group than the model group (P < 0.05). Immunohistochemical staining showed that adipose-derived mesenchymal stem cells were able to survive in the infarcted myocardial tissues, and the expression of cardiac troponin T in the cell transplantation group was significantly higher than that in the model group (P < 0.05). Experimental data show that adipose-derived mesenchymal stem cell transplantation can protect the myocardial tissues after myocardial infarction, and effectively improve the myocardial function.       

Gene expression of macrophage colony-stimulating factor and its receptor in human placenta and decidua.

Macrophage colony-stimulating factor (M-CSF) induces proliferation of monocyte/macrophage progenitor cells and can also activate some functions of mature cells including fetally derived placental cells. To study the role of M-CSF in the pregnant female reproductive tract, the expression of M-CSF mRNA and its receptor, c-fms proto-oncogene, in human placenta and decidua was identified. M-CSF and c-fms mRNAs, 4.7Kb and 3.9Kb respectively, were detected by Northern blotting in the early stage placenta and subsequently increased during pregnancy. These mRNAs were not detected in the nonpregnant endometrium but were strongly induced in maternal decidua with the same mRNA size as in the placenta. Northern blot hybridization on the endometrium of a pseudopregnant uterus revealed that the expression of endometrial M-CSF and c-fms mRNAs is regulated by synergistic action of female sex steroid hormones. These findings indicate that, in an autocrine and/or paracrine manner, M-CSF is deeply involved in the local proliferation and differentiation of cells at the materno-fetal interface, and support the placental immunotrophism hypothesis.     

自体骨髓间充质干细胞移植梗死心肌猪的心功能变化

背景：干细胞移植可改善缺血性心肌血供并改善心功能。 目的：进一步验证自体骨髓间充质干细胞在心肌梗死后的应用及效果评价。 方法：15只健康太湖梅山猪通过冠脉栓塞建立心肌梗死模型。随机分为3组,每组5只,其中2组分别在心肌梗死后3 h,2周行自体骨髓干细胞移植,模型组不移植细胞。行心脏超声观察心脏功能各指标的改变;并在不同时间点检测血清血管内皮生长因子值;在实验终点取大体标本并通过免疫组织化学检测移植细胞在心肌内定植及分化情况,检测心肌血管密度。 结果与结论：心肌梗死3 h组与模型组比较,射血分数、左室舒张期内径、左室收缩期内径各项心功能指标及心肌血管密度、不同时间点血清血管内皮生长因子水平差异无显著性意义。心肌梗死后2周移植组与模型组相比,心功能指标均有改善,心肌血管密度大于模型组,血清血管内皮生长因子水平明显高于较移植前(P < 0.05)。提示不同时间点心肌微环境对于骨髓来源的间充质干细胞分化及定植的影响,心肌梗死后急性期内局部微环境不利于移植细胞的存活,在瘢痕修复早期行骨髓干细胞移植对骨髓干细胞的分化和定植以及对心功能的改善有较好的效果。     

A degradable,bioactive, gelatinized alginate hydrogel to improve stem cell/growth factor delivery and facilitate healing after myocardial infarction

Despite remarkable effectiveness of reperfusion and drug therapies to reduce morbidity and mortality following myocardial infarction (MI), many patients have debilitating symptoms and impaired left ventricular (LV) function highlighting the need for improved post-MI therapies. A promising concept currently under investigation is intramyocardial injection of high-water content, polymeric biomaterial gels (e.g., hydrogels) to modulate myocardial scar formation and LV adverse remodeling. We propose a degradable, bioactive hydrogel that forms a unique microstructure of continuous, parallel capillary-like channels (Capgel). We hypothesize that the innovative architecture and composition of Capgel can serve as a platform for endogenous cell recruitment and drug/cell delivery, therefore facilitating myocardial repair after MI.