骨髓干细胞动员与移植治疗心肌梗死的比较

目的：比较骨髓干细胞动员与骨髓单个核细胞移植对兔心肌梗死的治疗作用，探讨更有效、更适用的干细胞治疗心肌梗死的方法。 方法： 将30只新西兰兔采用结扎前降支的方法复制心肌梗死模型，随机分为动员组、移植组和对照组，动员组（n=10）心梗后3 h开始皮下注射粒细胞集落刺激因子（G-CSF）30 μg·kg-1·d-1，连续使用5 d，第5 d抽取静脉血约10 mL，分离单个核细胞(BMCs)用5-溴脱氧尿嘧啶核苷（BrdU）标记后，经静脉注入动物体内。移植组（n=10）心梗后7-10 d，抽取骨髓3-5 mL,分离MNCs用BrdU标记，然后开胸将细胞移植至梗死区，对照组（n=10）不采取任何治疗措施。心梗后1周及5周采用超声心动图（UCG）检查心脏功能变化，5周时作血液动力学测定，取心脏作免疫组织化学鉴定。 结果： 心梗后5周，动员组左室射血分数（EF）明显高于1周时，移植组无变化，对照组显著下降。5周时动员组及移植组左室舒张末压（LVEDP）、+dp/dtmax和-dp/dtmax与对照组相比均有显著差异。动员组及移植组在心肌梗死区均发现有BrdU标记的阳性细胞，两组梗塞区血管密度明显高于对照组，但均未发现有新生的平滑肌细胞及心肌细胞。 结论： 骨髓干细胞动员及BMCs移植治疗心肌梗死，均能通过促进梗死区血管新生，明显改善心脏功能，骨髓干细胞动员可能为心肌梗死的治疗提供一种新的无创性手段。     

Cardiac stem cells in brown adipose tissue express CD133 and induce bone marrow nonhematopoietic cells to differentiate into cardiomyocytes

Recently, there has been noteworthy progress in the field of cardiac regeneration therapy. We previously reported that brown adipose tissue (BAT) contained cardiac progenitor cells that were relevant to the regeneration of damaged myocardium. In this study, we found that CD133-positive, but not c-Kit- or Sca-1-positive, cells in BAT differentiated into cardiomyocytes (CMs) with a high frequency. Moreover, we found that CD133(+) brown adipose tissue-derived cells (BATDCs) effectively induced bone marrow cells (BMCs) into CMs. BMCs are considered to have the greatest potential as a source of CMs, and two sorts of stem cell populations, the MSCs and hematopoietic stem cells (HSCs), have been reported to differentiate into CMs; however, it has not been determined which population is a better source of CMs. Here we show that CD133-positive BATDCs induce BMCs into CMs, not through cell fusion but through bivalent cation-mediated cell-to-cell contact when cocultured. Moreover, BMCs induced by BATDCs are able to act as CM repletion in an in vivo infarction model. Finally, we found that CD45(-)CD31(-) CD105(+) nonhematopoietic cells, when cocultured with BATDCs, generated more than 20 times the number of CMs compared with lin(-)c-Kit(+) HSCs. Taken together, these data suggest that CD133-positive BATDCs are a useful tool as CM inducers, as well as a source of CMs, and that the nonhematopoietic fraction in bone marrow is also a major source of CMs. Disclosure of potential conflicts of interest is found at the end of this article.     

Percutaneous coronary injection of bone marrow cells in small experimental animals: small is not too small

Intracoronary infusion of bone marrow cells (BMCs) is thought to induce cardiac regeneration in ischemic heart disease and dilated cardiomyopathy. The aim of our study was to develop a new method to inject BMCs into coronary arteries of small experimental animals. Transient atrioventricular block (AVB) was induced in 25 rats and 39 hamsters by intracarotid injection of adenosine 5'-triphosphate (ATP). Contrast echocardiography was obtained. BMCs (0.2-0.5 ml) were collected through femoral puncture, stained with PKH26 and injected into the carotid artery (CA). Animals were immediately sacrificed or followed for 1 month. To evaluate BMCs transfer from CA to myocardium, AVB and BMCs injections were performed in 10 hamsters subjected to coronary ligation for 30 min. Induction of transient AVB was possible in all animals by injecting 20-30 mg of ATP. Animals recovered a basal cardiac activity spontaneously or by dopamine injection. Flash injection of contrast medium through the CA induced staining of aortic root, coronary arteries, and myocardium. BMCs injection was possible in all cases. No immediate or late ECG changes were observed. Immediately after injection in healthy animals, histological examination showed the presence of BMCs in small coronary arteries and, after 1 month, the absence of infarction. In ischemic hearts, the presence of BMCs in the myocardium was observed 24h after ischemia. ATP-induced AVB block allows for percutaneous intracoronary injection of BMCs in small experimental animals with no immediate or late mortality and morbidity. This method offers new perspectives for the investigation of BMCs coronary infusion and engraftment in heart diseases.     

Implantation of bone marrow mononuclear cells using injectable fibrin matrix enhances neovascularization in infarcted myocardium

Neovascularization may improve cardiac function and prevent further scar tissue formation in infarcted myocardium. A number of studies have demonstrated that bone marrow-derived cells have the potential to induce neovascularization in ischemic tissues. In this study, we hypothesized that implantation of bone marrow mononuclear cells (BMMNCs) using injectable fibrin matrix further enhances neovascularization in infarcted myocardium compared to BMMNC implantation without matrix. To test this hypothesis, infarction was induced in rat myocardium by cryoinjury. Three weeks later, rat BMMNCs were mixed with fibrin matrix and injected into the infarcted myocardium. Injection of either BMMNCs or medium alone into infarcted myocardium served as controls. Eight weeks after the treatments, histological analyses indicated that implantation of BMMNCs using fibrin matrix resulted in more extensive tissue regeneration in the infarcted myocardium compared to BMMNC implantation without matrix. Examination with fluorescence microscopy revealed that cells labeled with a fluorescent dye prior to implantation survived in the infarcted myocardium at 8 weeks of implantation. Importantly, implantation of BMMNCs using fibrin matrix resulted in much more extensive neovascularization in infarcted myocardium than BMMNC implantation without matrix. The microvessel density in infarcted myocardium was significantly higher (p < 0.05) when BMMNCs were implanted using fibrin matrix (350 +/- 22 microvessels/mm2) compared to BMMNC implantation without matrix (262 +/- 13 microvessels/mm2) and medium injection (76 +/- 9 microvessels/mm2). In addition, average internal diameter of microvessels was significantly larger (p < 0.05) in BMMNC implantation with fibrin matrix group (14.6 +/- 1.2 microm) than BMMNC implantation without matrix group (10.2 +/- 0.7 microm) and medium injection group (7.3 +/- 0.5 microm). These results suggest that fibrin matrix could serve as a cell implantation matrix that enhances neovascularization efficacy for myocardial infarction treatment.     

骨髓间充质干细胞体外构建工程化心肌组织的生存

背景：到目前为止,工程化心肌组织仍然面临很多的问题。研究证实,骨髓间充质干细胞可分化为心肌样细胞;聚乙交酯、聚己内酯为常用的人工高分子材料,生物相容性良好。 目的：观察体外构建骨髓间充质干细胞-聚乙交酯-聚己内酯共聚物补片在正常心肌组织和梗死后心肌组织中的生长情况。 方法：SD大鼠骨髓间充质干细胞采用贴壁分离筛选法进行分离、培养,选取第3代进行体外DAPI标记。制作骨髓间充质干细胞悬液(2×106/cm2)种植于聚乙交酯-聚己内酯共聚物上形成骨髓间充质干细胞-聚乙交酯-聚己内酯共聚物补片。培养48 h在电镜下观察;苏木精-伊红染色后在光学显微镜下观察。大鼠结扎左冠状动脉前降支制作心肌梗死模型。将补片植入到正常心肌组织和梗死后心肌组织培养5周,行病理学检查了解骨髓间充质干细胞在组织中的存活情况。 结果与结论：光学显微镜和电镜观察结果示,骨髓间充质干细胞在聚乙交酯-聚己内酯共聚物支架中呈三维生长,细胞与支架黏附良好。在激光共聚焦显微镜下,对比观察补片植入正常心肌组织后第1周和第5周切片结果,同第1周相比,第5周的心肌组织内出现DAPI标记的骨髓间充质干细胞;心肌梗死区出现DAPI标记的骨髓间充质干细胞。苏木精-伊红染色结果示,梗死区出现骨髓间充质干细胞。提示骨髓间充质干细胞在聚乙交酯-聚己内酯共聚物支架上贴附生长,黏附良好。骨髓间充质干细胞-聚乙交酯-聚己内酯共聚物补片可用于心肌组织修复。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

Simultaneous injection of bone marrow cells and stromal cells into bone marrow accelerates hematopoiesis in vivo

We have previously demonstrated that stromal cells can support the proliferation and differentiation of hematopoietic cells in vitro and in vivo and that a major histocompatibility complex restriction exists between hematopoietic stem cells and stromal cells. We have also found that intra-bone marrow (IBM) injection of allogeneic bone marrow cells (BMCs) leads to more rapid reconstitution of hematopoietic cells than intravenous injection. In the present study, we examine the effect of simultaneous injection of stromal cells and BMCs into the same bone marrow on the recovery of donor hematopoietic cells and demonstrate that simultaneous IBM injection of BMCs plus stromal cells is more effective in reconstituting recipients with donor hematopoietic cells than intravenous injection of BMCs plus stromal cells or IBM injection of BMCs alone.     

Airway delivery of soluble factors from plastic-adherent bone marrow cells prevents murine asthma

Asthma affects an estimated 300 million people worldwide and accounts for 1 of 250 deaths and 15 million disability-adjusted life years lost annually. Plastic-adherent bone marrow-derived cell (BMC) administration holds therapeutic promise in regenerative medicine. However, given the low cell engraftment in target organs, including the lung, cell replacement cannot solely account for the reported therapeutic benefits. This suggests that BMCs may act by secreting soluble factors. BMCs also possess antiinflammatory and immunomodulatory properties and may therefore be beneficial for asthma. Our objective was to investigate the therapeutic potential of BMC-secreted factors in murine asthma. In a model of acute and chronic asthma, intranasal instillation of BMC conditioned medium (CdM) prevented airway hyperresponsiveness (AHR) and inflammation. In the chronic asthma model, CdM prevented airway smooth muscle thickening and peribronchial inflammation while restoring blunted salbutamol-induced bronchodilation. CdM reduced lung levels of the T(H)2 inflammatory cytokines IL-4 and IL-13 and increased levels of IL-10. CdM up-regulated an IL-10-induced and IL-10-secreting subset of T regulatory lymphocytes and promoted IL-10 expression by lung macrophages. Adiponectin (APN), an antiinflammatory adipokine found in CdM, prevented AHR, airway smooth muscle thickening, and peribronchial inflammation, whereas the effect of CdM in which APN was neutralized or from APN knock-out mice was attenuated compared with wild-type CdM. Our study provides evidence that BMC-derived soluble factors prevent murine asthma and suggests APN as one of the protective factors. Further identification of BMC-derived factors may hold promise for novel approaches in the treatment of asthma.     

Choroidal neovascularization is provided by bone marrow cells

Choroidal neovascularization (CNV) is a known cause of age-related macular degeneration (ARMD). Moreover, the most common cause of blindness in the elderly in advanced countries is ARMD with CNV. It has recently been shown that bone marrow cells (BMCs) can differentiate into various cell lineages in vitro and in vivo. Adults maintain a reservoir of hematopoietic stem cells included in BMCs that can enter the circulation to reach various organs in need of regeneration. It has recently been reported that endothelial progenitor cells (EPCs) included in BMCs are associated with neovascularization. We examine the role of BMCs in CNV using a model of CNV in adult mice. Using methods consisting of fractionated irradiation (6.0 Gy x 2) followed by bone marrow transplantation (BMT), adult mice were engrafted with whole BMCs isolated from transgenic mice expressing enhanced green fluorescent protein (EGFP). Three months after BMT, we confirmed that the hematopoietic cells in the recipients had been completely replaced with donor cells. We then carried out laser photocoagulation to induce CNV in chimeric mice (donor cells >95%). Two weeks after the laser photocoagulation, by which time CNV had occurred, immunohistochemical examination was carried out. The vascular wall cells of the CNV expressed both EGFP and CD31. These findings indicate that newly developed blood vessels in the CNV are derived from the BMCs and suggest that the inhibition of EPC mobilization from the bone marrow to the eyes could be a new approach to the fundamental treatment of CNV in ARMD.     

Intracardiac fibroblasts, but not bone marrow derived cells, are the origin of myofibroblasts in myocardial infarct repair.

SUMMARY: Origin of myofibroblasts in infarcted myocardium was examined by using rats in which bone marrow of green fluorescent protein (GFP)-transgenic mice had been transplanted. GFP was not detected in myofibroblasts at either 3 or 7 days after infarction, suggesting that proliferating myofibroblasts in infarcted myocardium are derived from resident fibroblasts rather than circulating precursor cells of bone marrow origin. BACKGROUND: Myofibroblasts play important roles in the repair process of myocardial infarct, and their origin has been assumed to be interstitial fibroblasts in the heart. However, bone marrow-derived myofibroblasts have recently been identified in pathological fibrosis in extracardiac tissues. In this study, we aimed to determine whether some of the myofibroblasts in infarcted myocardium are derived from circulating precursor cells of bone marrow origin. METHODS AND RESULTS: Bone marrow (BM) of GFP-transgenic mice was transplanted into nude rats, and their coronary arteries were occluded for 60 min and reperfused for 3 or 7 days. Non-BM-transplanted rats served as controls. At 3 days after infarction, some endothelial cells were GFP-positive, indicating that they were of bone marrow origin. Predominant cells in infarcted regions were macrophages and neutrophils, and there were only a small number of vimentin-positive cells and fewer myofibroblasts, both of which were GFP-negative. At 7 days after infarction, there were numerous myofibroblasts in granulation tissue replacing necrotic myocytes, and none of them showed GFP signals, whereas some cells were positive for both GFP and vimentin. Appearance of myofibroblasts and extent of the infarct repair in BM-transplanted and those in non-transplanted rats were similar. CONCLUSIONS: The findings in this study suggest that proliferating myofibroblasts in infarcted myocardium are derived from resident fibroblasts rather than circulating precursor cells of bone marrow origin.     

Intra-bone marrow injection of donor bone marrow cells suspended in collagen gel retains injected cells in bone marrow, resulting in rapid hemopoietic recovery in mice

We have recently developed an innovative bone marrow transplantation (BMT) method, intra-bone marrow (IBM)-BMT, in which donor bone marrow cells (BMCs) are injected directly into the recipient bone marrow (BM), resulting in the rapid recovery of donor hemopoiesis and permitting a reduction in radiation doses as a pretreatment for BMT. However, even with this IBM injection, some of the injected BMCs were found to enter into circulation. Therefore, we attempted to modify the method to allow the efficient retention of injected BMCs in the donor BM. The BMCs of enhanced green fluorescent protein transgenic mice (C57BL/6 background) were suspended in collagen gel (CG) or phosphate-buffered saline (PBS), and these cells were then injected into the BM of irradiated C57BL/6 mice. The numbers of retained donor cells in the injected BM, the day 12 colony-forming units of spleen (CFU-S) counts, and the reconstitution of donor cells after IBM-BMT were compared between the CG and PBS groups. The number of transplanted cells detected in the injected BM in the CG group was significantly higher than that in the PBS group. We next carried out CFU-S assays. The spleens of mice in the CG group showed heavier spleen weight and considerably higher CFU-S counts than in the PBS group. Excellent reconstitution of donor hemopoietic cells in the CG group was observed in the long term (>100 days). These results suggest that the IBM injection of BMCs suspended in CG is superior to the injection of BMCs suspended in PBS.     

低氧增强骨髓间充质干细胞对缺氧诱导心肌细胞凋亡的可能性

背景：骨髓间充质干细胞移植入缺血心肌后存活率低,而低氧有可能增强骨髓间充质干细胞的增殖,促进其存活。 目的：体外模拟心肌细胞缺血微环境,探索低氧预处理后,骨髓间充质干细胞对持续缺氧诱导的心肌细胞凋亡的保护作用。 方法：取第4代SD大鼠骨髓间充质干细胞用于制备条件培养液。取胚胎大鼠心肌细胞株,随机分成4组：对照组：心肌细胞正常培养组;模型组：心肌细胞单纯缺氧;骨髓间充质干细胞组：心肌细胞与骨髓间充质干细胞条件培养液共缺氧;低氧组：心肌细胞与骨髓间充质干细胞低氧条件培养液共缺氧。MTT检测各组细胞活力变化,Annexin V-FITC双染标记心肌细胞凋亡,免疫组化检测各组Bax和Bcl-2蛋白的表达。 结果与结论：免疫组化显示,低氧组的Bcl-2表达较其他各组增强,而Bax的表达比模型组和骨髓间充质干细胞组减弱,Bcl-2/Bax比值最大。与对照组和骨髓间充质干细胞组相比,低氧组的细胞活力高(P < 0.05),凋亡率降低(P < 0.05)。提示低氧可能是通过增强旁分泌机制,从而对Bax和Bcl-2进行调节,对心肌细胞凋亡有保护效应。     

Chimerism of cardiomyocytes and endothelial cells after allogeneic bone marrow transplantation in chronic myeloid leukemia. An autopsy study

The results of a number of animal experimental studies are in keeping with the finding that hematopoietic progenitors can generate cardiomyocytes and endothelial cells. As a consequence innovative therapeutic strategies have been suggested to possibly ameliorate the outcome of coronary artery disease. However, there is no information available at present whether this pathomechanism is also effective in humans, in particular without prior ischemic lesion of the myocardium. Therefore an autopsy study was performed on cadaver hearts derived from five male patients with chronic myeloid leukemia who received full unmanipulated bone marrow grafts from female donors 21-631 days before death. The purpose of this investigation was to detect and quantify a putative chimerism of cardiomyocytes and endothelial cells (intramural and subepicardial vessels). Genotyping was carried out by applying X- or Y-chromosome-specific DNA probes (fluorescence in-situ hybridisation) on routinely formalin-fixed specimens of the myocardium. To test the sensitivity of our method, cadaver hearts from two males and two females without a history of transplantation served as controls. In contrast to a totally corresponding sex-matched genotyping in 780 cardiomyocytes and 155 endothelial cells of the control group, the five male patients with a previous transplantation revealed significantly different results. A mixed chimerism was identifiable in 57 out of 890 counted cardiomyocytes (6.4%) and in 19 out of 322 endothelial cells (5.8%). These findings support the assumption that in addition to endothelial cells there is also a cardiomyogenic potential of bone marrow stem cells which exists without prior (ischemic) damage to the heart. However, further investigations are necessary to identify, isolate and enrich the cardiomyocytic stem cells more specifically for future curative therapeutic options in patients with severe ischemic cardiomyopathy.     

The mechanical coupling of adult marrow stromal stem cells during cardiac regeneration assessed in a 2-D co-culture model

Postnatal cardiomyocytes undergo terminal differentiation and a restricted number of human cardiomyocytes retain the ability to divide and regenerate in response to ischemic injury. However, whether these neo-cardiomyocytes are derived from endogenous population of resident cardiac stem cells or from the exogenous double assurance population of resident bone marrow-derived stem cells that populate the damaged myocardium is unresolved and under intense investigation. The vital challenge is to ameliorate and/or regenerate the damaged myocardium. This can be achieved by stimulating proliferation of native quiescent cardiomyocytes and/or cardiac stem cell, or by recruiting exogenous autologous or allogeneic cells such as fetal or embryonic cardiomyocyte progenitors or bone marrow-derived stromal stem cells. The prerequisites are that these neo-cardiomyocytes must have the ability to integrate well within the native myocardium and must exhibit functional synchronization. Adult bone marrow stromal cells (BMSCs) have been shown to differentiate into cardiomyocyte-like cells both in vitro and in vivo. As a result, BMSCs may potentially play an essential role in cardiac repair and regeneration, but this concept requires further validation. In this report, we have provided compelling evidence that functioning cardiac tissue can be generated by the interaction of multipotent BMSCs with embryonic cardiac myocytes (ECMs) in two-dimensional (2-D) co-cultures. The differentiating BMSCs were induced to undergo cardiomyogenic differentiation pathway and were able to express unequivocal electromechanical coupling and functional synchronization with ECMs. Our 2-D co-culture system provides a useful in vitro model to elucidate various molecular mechanisms underpinning the integration and orderly maturation and differentiation of BMSCs into neo-cardiomyocytes during myocardial repair and regeneration.     

Autologous bone marrow cell infusion therapy for liver cirrhosis--now and future

Infused (transplanted) green fluorescent protein (GFP)-positive bone marrow cells (BMCs) migrated into the peri-portal regions of the cirrhotic mouse liver induced continuous CCl4 injection without irradiation (without bone marrow ablation). The infused GFP-positive BMCs differentiated into hepatoblasts detected with Liv2-antibody and then differentiated into albumin-producing hepatocytes. The differentiation "niche" induced by persistent liver damage due to continuous CCl4 injection seems to be an essential factor. Microarry analysis showed that at an early stage after BMC infusion through mouse tail vein, the genes related to degradation of extracellular matrix (ECM) e.g. MMP-9 were activated. BMC infusion improved liver fibrosis and the survival rate. Recent our finding indicates that mesencymal bone marrow cells will differentiate to hepatocytes and FGF2 will accelerate this differentiation of BMC to hepatocyte. Based on the results obtained in basic research using the GFP/CCl4 model, human trials are now undergoing. We have done this autologous bone marrow cell infusion therapy for 19 patients with advanced liver cirrhosis. The clinical study of liver cirrhosis (LC) cases that underwent autologous bone marrow cell infusion from peripheral vein is as follows. Subjects were LC patients with T.B. of < 3.0 mg/dl, Plt of > 5(10(10)/l) and no viable hepatocellular carcinoma by diagnostic imaging. Autologous bone marrow cells (BMCs, 400 ml) were isolated from the ilium under general anesthesia. BMCs were separated by cell washing and were infused via the peripheral vein. After BMC infusion, liver function was monitored by blood examination for 24 weeks. We could follow 9 cases more than 6 months so far. After washing, 5.20 +/- 0.63 x 10(9) BMCs were infused into LC patients. Serum albumin level and total protein were significantly improved at 24 weeks after BMC infusion (p < 0.05). The Child-Pugh score was significantly improved at 4 week and 24 weeks after BMC infusion (p < 0.05). No major adverse effects were noted. In conclusion, autologous BMC infusion might be considered as a novel treatment for advanced LC patients.     

大鼠骨髓间充质干细胞移植治疗心肌梗死的实验研究

目的　研究骨髓间充质干细胞(BMSCs)移植对心肌梗死大鼠左心功能的影响以及在心肌病大鼠体内存活、分化的情况。 方法　结扎左冠状动脉前降支制备大鼠心肌梗死模型,采用同种异体大鼠BMSCs 体外分离、纯化、扩增,胶体金标记。按照对BMSCs的处理方式和心肌内注射的成分不同随机分为3组:A组接受BMSCs移植治疗;B组移植经5-氮胞苷体外诱导的BMSCs;C组列为对照组,注射等量培养基;每组12只。4周后通过血流动力学各项指标评价BMSCs移植对大鼠心功能的改善情况;免疫组织化学法检测移植细胞的存活和分化。 结果 与对照组C组相比,移植组A, B两组左心功能显著改善（P<0.01）。A, B两组之间无显著性差异。移植组左心室收缩压（LVSP）、左心室等容期压力最大变化速率（±dp/dtmax）明显高于对照组（P<0.01）,左心室舒张末期压（LVEDP）明显低于对照组（P<0.01）。移植的BMSCs能在心外膜下、梗死区及与正常心肌的交界处存活并向心肌细胞分化, 心肌特异性肌钙蛋白T（cTnT）和α－横纹肌肌动蛋白（α-sarcomeric actin）表达阳性。 结论 同种异体BMSCs移植入大鼠心肌梗死区后能明显改善心功能并向心肌细胞转化。     

Syngenic bone marrow cells restore hepatic function in carbon tetrachloride-induced mouse liver injury

Progenitor cells in bone marrow have been explored for the treatment of liver injury. Stem cell homing to the injured tissue is regulated through stromal cell derived factor-1 (SDF-1) and its receptor CXCR4. We hypothesized that syngenic bone marrow cells (BMCs) would restore hepatic function in the injured liver through the regulation by SDF-1/CXCR4 system. After injecting carbon tetrachloride (CCl(4)), the mice were injected with syngenic BMCs or normal saline. Morphological and functional analysis of the liver was performed. Flow cytometry for the stem cell markers and CXCR4 was done with the liver, BM, and spleen cells from each group. Carboxyfluorescein diacetate succinimidyl ester was used to trace the homing of transplanted BMCs. The SDF-1 expression of the liver was assessed by immunohistochemistry. Hepatosplenomegaly and necrosis of the CCl(4)-injected mouse liver were improved after BMCs transplantation The hepatic enzymes were increased after injury and then decreased after BMCs transplantation. The expression of stem cell markers and CXCR4 was exclusively increased in the damaged liver compared to the BM and spleen, and even more elevated after BMCs transplantation. SDF-1 expression in the liver was observed after CCl(4) injection and it was elevated after BMCs transplantation. The intrinsic and extrinsic BMCs migrate specifically to the injured liver rather than BM or spleen, and the transplanted BMCs contribute to the repair of the damaged liver. SDF-1/CXCR-4 interaction plays a role in stem cell homing toward the damaged organ, and transplanted BMCs are involved in the up-regulated SDF-1 expression seen in the injured liver.     

Angiogenic growth factor release system for in vivo tissue engineering: a trial of bone marrow transplantation into ischemic myocardium

For successful in vivo tissue engineering, a growth factor release system will be useful. We adopted autologous bone marrow transplantation as an angiogenic growth factor release system. Bone marrow transplanted into a synthetic vascular prosthesis produced continuous synthesis of angiogenic growth factors, resulting in rapid neointima formation on the prosthesis after implantation. We expected a similar angiogenic phenomenon to occur if bone marrow was transplanted into ischemic myocardium. Bone marrow was transplanted into ischemic myocardium created in dogs. Marrow cells continued synthesis of angiogenic growth factors, which were effective in protecting the capillary network from ischemia, but not myocytes. Autologous bone marrow was injected intramuscularly into ischemic myocardium created in the left ventricular wall of dogs. Control operations were performed without bone marrow. On days 3 and 7, marrow cells survived, and their adjacent cells and the surrounding extracellular matrix were immunohistochemically bFGF reactive. At 3 weeks, no marrow cells were identified. Myocytes disappeared, but the capillary blood vessel networks remained. With some exceptions, these capillaries did not contain blood cell components. In the controls, scar tissue with a very small number of capillaries was formed. In conclusion, marrow cells survived for a short period of time after transplantation, and continued synthesis of angiogenic growth factors, which were effective in protecting endothelial cells from ischemia, but not myocytes. Therefore, the results also suggest that there are limitations in the treatment of ischemic myocardium using angiogenic growth factors alone.     

基质细胞衍生因子对骨髓干细胞迁移分化的影响

骨髓干细胞具有很强的可塑性，可向多种组织细胞横向分化，是细胞移植的最好种子之一。体内外许多试验证实，某些细胞因子可以影响移植细胞的微环境，进而影响骨髓干细胞的动员、迁移及分化。基质细胞衍生因子属于趋化因子中CXC亚家族，特异性引起表达CXCR4的骨髓干细胞趋化反应，就基质细胞衍生因子对骨髓干细胞动员、迁移及分化的影响作一综述。     

体外心肌梗死微环境下大鼠骨髓间充质干细胞向内皮样细胞的分化

背景：间充质干细胞来源于中胚层,具有多向分化的能力。有研究显示骨髓间充质干细胞有向内皮细胞分化的能力,从而有助于心肌梗死后心脏新生血管的形成和心肌修复。 目的：观察骨髓间充质干细胞体外成内皮样细胞分化的特点,以及体外模拟心肌梗死微环境对骨髓间充质干细胞向内皮样细胞分化的影响。 方法：骨髓取自SD大鼠股骨和胫骨,骨髓分离培养骨髓间充质干细胞,体外扩增,对其形态学、增殖能力及多向分化能力进行鉴定;建立大鼠心肌梗死模型,制备8 h、3 d、1周、2周、4周梗死后不同时间点心肌组织的匀浆,分别加入到由血管内皮生长因子、碱性成纤维细胞生长因子β、胰岛素样生长因子1组成的内皮细胞诱导体系中,共同诱导2周后,观察不同时间的心肌组织匀浆对骨髓间充质干细胞增殖和成内皮分化的影响,检测vWF特异性抗原及表达的阳性率。 结果与结论：通过对培养细胞的形态学及功能鉴定,证明其为骨髓间充质干细胞,并具有成骨、成脂肪细胞、成内皮样细胞分化的能力。加入生长因子诱导体系诱导后的细胞部分表达vWF,梗死心肌匀浆与生长因子共同作用,能促进骨髓间充质干细胞向内皮细胞分化,vWF阳性率提高(P < 0.05)。RT-PCR显示加入梗死1周心肌组织匀浆诱导的骨髓间充质干细胞其vWF阳性表达率最高。提示骨髓间充质干细胞是一种具有多向分化能力的有别于造血干细胞的另一种骨髓干细胞。骨髓间充质干细胞具有向内皮分化的能力,且加入梗死心肌组织匀浆的诱导体系在体外可促进骨髓间充质干细胞向内皮细胞的分化。应用骨髓间充质干细胞治疗的最佳时机在1周为宜。