液氮冻伤术建立动脉粥样硬化破裂斑块及血栓模型

目的创建一种操作简单、经济实用的动脉粥样硬化（AS）破裂斑块及血栓动物模型。方法21只雄性纯种新西兰白兔随机分为两组：液氮冻伤＋高脂喂养组（A组=11只）和高脂喂养组（B组=10只）。A组实施右颈总动脉内膜液氮冻伤术结合高脂饲料喂养,B组单纯给予高脂饲料喂养。8周末以液氮激发斑块破裂,激发前后分别采血检测血脂、hsC-RP、MMP-9及PAI-1水平;激发48h后处死所有动物,取出右颈总动脉作HE染色及免疫组化染色等,光镜及电镜观察破裂斑块及血栓形成情况。结果8周后兔血脂水平明显升高;激发后血浆hsC-RP、MMP-9及PAI-1均明显升高;所有A组兔子的右颈总动脉均可见AS破裂斑块及血栓形成,而B组兔子未见斑块或血栓形成;所建立的破裂斑块在组织结构、细胞构成、生长特征和脂质沉积方面与人类斑块相似。结论液氮冻伤术能简便、快速、高效地建立AS破裂斑块及血栓模型,从而为研究人类AS破裂斑块及血栓形成的机理和药物干预治疗提供了一种新型动物模型。     

自体骨髓单核细胞移植在肝纤维化兔肝脏内的定植能力

目的建立四氯化碳诱导的兔肝纤维化动物模型,观察体外分离标记的自体骨髓单核细胞（ABM-MNCs）经肠系膜上静脉自体移植至肝纤维化区及周边区后的存活、定植状况。方法将40只普通级日本大耳家兔随机分为细胞移植组和对照组各20只,实验组腹腔注射40%CCl4橄榄油溶液建立肝纤维化模型,对照组腹腔注射等量生理盐水。细胞移植组于模型稳定后自体髂骨处抽取骨髓,采用氯化氨红细胞溶解法分离得到单核细胞,以5溴-2脱氧尿嘧啶核苷（BrdU）标记体外ABM-MNCs及鉴定;分离培养ABM-MNCs,将3×10^9个ABM-MNCs经肠系膜上静脉回输体内,对照组回输等量生理盐水,移植前、移植后3、7、14、21 d分别取肝组织固定,进行免疫组织化学检测。结果BrdU体外标记ABM-MNCs的免疫组织化学表现示：20μmol/L BrdU孵育ABM-MNCs 72 h的阳性标记率达95%;肝组织20μmol/L BrdU免疫组化染色切片显示：自体骨髓单核细胞移植后第3天,肝小叶中央静脉周围BrdU染色阳性,随着时间的推移,阳性染色逐渐增强,并逐步向肝组织内部延伸。阳性染色主要分布于肝组织汇管区周围组织,而对照组BrdU染色则阴性。结论ABM-MNCs经肠系膜上静脉移植后,可在纤维化区及周边区存活,定植。     

同种异体骨髓干细胞移植联合VEGF干预对心肌梗死后左室功能的影响

目的:探讨同种异体骨髓间质干细胞(BMSCs)移植联合血管内皮生长因子VEGF静脉注射对兔急性心肌梗死心功能的影响.方法:体外分离、纯化、培养兔BMSCs,以BrdU标记细胞.结扎冠状动脉建立急性心肌梗死模型后,随机将其分为4组(n=8),进行心肌内BMSCs移植和/或VEGF静脉注射,组Ⅰ:BMSCs移植+VEGF静脉注射;组Ⅱ:BMSCs移植;组Ⅲ:VEGF静脉注射:组Ⅳ:DMEM注射作为对照组.4周后行免疫组化和超声心动图检查.结果:组Ⅰ和组Ⅱ梗死及缺血心肌处可见大量BrdU标记的移植细胞,EF值组Ⅰ>组Ⅱ>组Ⅲ,组Ⅳ(均为P<0.01).结论:同种异体骨髓间质干细胞移植联合VEGF静脉注射能改善心功能,有利于心肌梗死后的康复.     

骨髓动员对骨髓造血干细胞在心肌梗死后心脏中定植及分化的影响

目的观察小鼠心肌梗死后骨髓造血干细胞在心脏内的分化及细胞因子的影响。方法C57/BL6小鼠60只分为骨髓动员组和对照组,先后行脾切除、骨髓移植（骨髓供体为增强绿色荧光蛋白转基因小鼠）、骨髓动员及建立心肌梗死模型。心肌梗死后3周将小鼠心脏取出并切片行组织学及激光共聚焦显微镜免疫荧光检查。结果骨髓动员可以增加EGFP阳性细胞在心脏中梗死区和边缘区的定植,但绝大多数EGFP阳性细胞都同时表达CD45。仅发现有极少数骨髓来源的心肌细胞、成纤维细胞及血管内皮细胞,且与骨髓动员无相关性。结论骨髓动员能够明显促进骨髓来源细胞定植入小鼠心脏的梗死区;极少数骨髓造血干细胞可以分化为心肌细胞,其数量远不足以修复梗死心肌及改善心功能;骨髓造血干细胞不参与梗死区疤痕形成的病理过程。     

Simvastatin 与rhG-CSF 促进兔颈总动脉球囊损伤后内膜修复 的实验研究

目的:观察辛伐他汀及重组人粒细胞集落刺激因子(rhG-CSF)在兔颈总动脉内膜损伤后对血管壁变化及外周血中CD34+细胞含量的影响。方法:雄性新西兰大白兔48只,随机均分为:单纯损伤组,辛伐他汀组,rhG-CSF组及辛伐他汀和rhG-CSF联合组(简称联合组),建立兔左颈总动脉内膜球囊导管损伤模型,术后给予辛伐他汀(10mg/kg/d经胃灌入)及rhG-CSF(100μg/d皮下注射)干预治疗,每组分别于术前1d、术后7d、14d、21d、28d抽取静脉血2ml,经流式细胞仪检测外周血中CD34+细胞含量;4周后处死所有动物取损伤段血管,弹力纤维染色,计算内膜厚度、中膜厚度、管腔面积(S)、内膜面积(Si)、中膜面积(Sm)及Si/Sm比值评价血管再狭窄程度。结果:①术前4组之间相比外周血CD34+细胞含量无明显差异(P>0.05);术后7d时各组外周血CD34+细胞含量最高,后逐渐下降,28d较低,但仍高于术前含量;rhG-CSF组及联合组与对照组相比外周血CD34+细胞明显增多(P<0.01,P<0.01);术后7d、14天时辛伐他汀组与单纯损伤组相比外周血CD34+细胞无明显差别(P>0.05)。术后21d、28天时辛伐他汀组与单纯损伤组相比外周血CD34+细胞有显著差异(P<0.05)。②与单纯损伤组相比辛伐他汀组、rhG-CSF组及联合组Si/Sm比值明显减小(P<0.05);辛伐他汀组和rhG-CSF组两组间比较无显著差别(P>0.05);联合组分别与辛伐他汀组、rhG-CSF组比较血管内膜增生更少,具有显著性(P<0.01,P<0.01)。结论:本实验研究发现辛伐他汀可促进损伤内膜修复及预防血管再狭窄,长期服用可以增加外周血CD34+细胞;rhG-CSF可明显增加外周血CD34+细胞及预防血管在狭窄;辛伐他汀与rhG-CSF联合用药可明显增加外周血CD34+细胞、加速内皮修复与预防再狭窄,较单一用药具有更好的疗效。     

粒细胞集落刺激因子对失代偿期肝硬化患者骨髓干细胞的动员效果及安全性观察

目的观察失代偿期肝硬化患者行自体骨髓干细胞移植前粒细胞集落刺激因子（G-CSF）对骨髓干细胞的动员效果及安全性。方法在51例失代偿期肝硬化患者行自体骨髓干细胞经肝动脉移植术前,连续2 d给予G-CSF 4μg/（kg·d）动员骨髓干细胞。抽取骨髓的当日化验血常规、肝肾功等指标;从患者髂后上棘抽取骨髓150-200 ml,分离收集骨髓单个核细胞并计数,应用流式细胞仪检测CD34＋细胞并计数,观察应用G-CSF期间不良反应的类型和发生率。患者治疗前后比较采用配对t检验进行统计学分析。结果G-CSF皮下注射后,外周血白细胞由术前（3.31±0.96）×10^9/L升至（11.35±1.92）×10^9/L（P〈0.01）,骨髓单个核细胞数（1.91±0.83）×10^9/kg,CD34＋细胞为（2.02±1.29）×10^7/kg;患者皮下注射后,发热率17.6﹪,体温最高38℃,停药后降至正常;腹部胀痛3例,四肢皮肤散发皮疹2例,均未给予特殊处理,2-3 d后恢复正常。结论给予G-CSF皮下注射后提取骨髓干细胞移植治疗失代偿期肝硬化的是一种临床确切有效的、安全的干细胞动员方法。     

BrdU体内示踪骨髓基质干细胞生物学状态的效果分析

目的:探讨5-溴脱氧尿嘧啶核苷(Brd U)体内示踪骨髓基质干细胞(BMSCs)生物学状态的效果。方法:抽取健康成年比格狗骨髓,在传代培养中进行Brd U标记并鉴定,体外实验中测定细胞周期、凋亡率和细胞活力;在体内实验中将标记Brd U的骨髓基质干细胞植入自体股骨头缺损处,另一侧单纯植入自体骨作为对照,记录成骨量与分子标记物的表达情况。结果:骨髓基质干细胞的Brd U体外标记率为85.2%。Brd U组的细胞凋亡率为3.62±1.33%,未标记组为3.52±1.08%;Brd U组与未标记组的细胞成活率分别为96.31±1.39%和95.20±2.10%,两组对比差异均无统计学意义(P0.05)。移植侧Brd U标记的骨髓基质干细胞免疫组化观察可见Brd U免疫组化染色阳性,阳性率为81.6%。骨髓基质干细胞移植侧缺损区的骨钙素、Ⅰ型胶原阳性细胞表达数量与强度明显高于对照侧缺损区;骨髓基质干细胞移植侧成骨量为17.46±2.12%,对照侧为9.06±1.24%,两两对比差异有统计学意义(P0.05)。结论:Brd U在体外示踪骨髓基质干细胞能有效反映细胞的生物学状态,体内示踪显示移植的骨髓基质干细胞能成活,能促进骨组织形成和坏死骨修复。     

生长激素-海藻酸钠-壳聚糖微胶囊促进骨折愈合的组织学研究

目的:观察生长激素-海藻酸钠-壳聚糖微胶囊促进兔挠骨骨折愈合的作用。方法:实验将新西兰兔80只,在制备新西兰兔右桡骨中段3mm骨缺损模型的基础上,随机分成四组:口服生长激素-海藻酸钠-壳聚糖微胶囊组、皮下注射生长激素组、口服空微胶囊组和生理盐水对照组。实验组口服生长激素-海藻酸钠-壳聚糖微胶囊和皮下注射生长激素,对照组口服空微胶囊。并于术后9、17、30、42d定期HE染色和地衣红染色观察各组的骨折愈合情况。结果:本实验HE染色结果表明,由于在骨缺损部位成纤维细胞产生的大量胶原纤维为基质,形成透明软骨及成骨细胞,骨小梁生长的基础,连接骨痂形成和骨髓腔贯通。而观察到生长激素微胶囊组各期提前生长及改建提前的形态。地衣红染色图像结果分析及直方图的分析表明:生长激素微胶囊组胶原纤维产生促进骨小梁提前形成,进而骨折处骨性骨痂的提前愈合和髓腔的提前贯通。结论:生长激素-海藻酸钠-壳聚糖微胶囊口服能促进骨折修复愈合。     

有氧运动与干细胞动员的缺血心脏血管新生研究进展

有氧运动具有明确的血管新生效应,包括缺血心脏,但其机制尚未完全阐明。心肌梗死(MI)后冠脉微血管新生是心脏修复的前提。新近研究表明,血管新生来源于体内干/祖细胞的动员与参与,并以旁分泌效应影响内皮细胞(EC)功能及微血管分布效果,运动可以动员、激活内源性干细胞因子和血管生成因子的表达与分泌,并能从表观遗传学角度影响心脏血管新生。探索不同运动方式及强度对缺血心脏血管新生的作用及其分子机制,对缺血心脏的预防及术后康复具有重要意义。本文从心脏血管新生及其调控机制、自体干细胞动员参与缺血心脏的血管新生和运动通过干细胞动员促进缺血心脏血管新生等方面综述运动促进缺血心脏血管新生的主要机制、存在问题及相关研究进展。     

TGF-β3与TIMP-2联合转染兔骨髓间充质干细胞复合丝素蛋白/壳聚糖生物支架修复兔软骨缺损(英文)

目的:TGF-β3广泛存在于骨组织、软骨组织中,能诱导体外培养的间充质干细胞向软骨分化、生长。TIMP-2能抑制MMP对软骨基质的降解,保护新生软骨组织。本实验探讨单纯TGF-β3和TGF-β3,TIMP-2联合转染兔骨髓间充质干细胞复合丝素蛋白壳聚糖/(silk fibrin/chitosan,SF/CS)生物支架植入动物体内修复兔膝关节软骨缺损的可行性及效果差异。方法:将新西兰大白兔20只分为4组,每组5只(支架组、未转染组、reAAV-TGF-β3转染组、reAAV-TGF-β3,reAAV-TIMP-2联合转染组)。在无菌条件下取兔第三代对数生长期骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs),用携带目的基因的重组腺相关病毒进行转染,将转染成功的BMSCs与SF-CS生物支架复合,分别植入兔膝关节软骨缺损处:未转染组植入SF-CS生物支架,未转染组植入未转染的BMSCs复合SF-CS生物支架,reAAV-TGF-β3转染组植入reAAV-TGF-β3转染的BMSCs复合SF-CS生物支架,reAAV-TGF-β3,TIMP-2联合转染组植入reAAV-TGF-β3,TIMP-2联合转染的BMSCs复合SF-CS生物支架。两月后处死家兔,肉眼观察以及HE染色评定缺损软骨修复情况。并进行软骨细胞特征性染色即甲苯胺蓝染色及II型胶原免疫组化染色鉴定。结果:两个月后除支架组外各实验组兔膝关节软骨缺损处均有软骨样物质形成,且联合转染组诱导的新生成分更接近缺损处周围正常软骨。联合转染组与reAAV-TGF-β3转染组;联合转染组与未转染组;reAAV-TGF-β3转染组与未转染组的评分差异均具有统计学意义(P0.05)。HE染色结果提示联合转染组软骨修复效果较单纯TGF-β3转染组更好。结论:单纯TGF-β3转染兔骨髓间充质干细胞对兔膝关节软骨缺损有修复作用,TGF-β3与TIMP-2联合转染组修复缺损效果更明显,提示TIMP-2与TGF-β3具有协同效应。     

Mesenchymal Stem Cells Stabilize Atherosclerotic Vulnerable Plaque by Anti-Inflammatory Properties

Background and objectives

Formation and progression of atherosclerotic vulnerable plaque (VP) is the primary cause of many cardio-cerebrovascular diseases such as acute coronary syndrome and stroke. It has been reported that bone marrow mesenchymal stem cells (MSC) exhibit protective effects against many kinds of diseases including myocardial infarction. Here, we examined the effects of intravenous MSC infusion on a VP model and provide novel evidence of its influence as a therapy in this animal disease model.

Subjects and methods

Thirty healthy male New Zealand white rabbits were randomly divided into a MSC, VP or stable plaque (SP) group (n = 10/group) and received high fat diet and cold-induced common carotid artery intimal injury with liquid nitrogen to form atherosclerotic plaques. Serum hs-CRP, TNF-α, IL-6 and IL-10 levels were measured by ELISA at 1, 2, 3, 7, 14, 21 and 28 days after MSC transplantation. The animals were sacrificed at 4 weeks after MSC transplantation. Lesions in the right common carotid were observed using H&E and Masson staining, and the fibrous cap/lipid core ratio of atherosclerotic plaques were calculated. The expression of nuclear factor κB (NF-κB) and matrix metalloproteinase 1, 2, 9 (MMP-1,2,9) in the plaque were detected using immunohistochemistry, and apoptotic cells in the plaques were detected by TUNEL. In addition, the level of TNF-α stimulated gene/protein 6 (TSG-6) mRNA and protein were measured by quantitative Real-Time PCR and Western blotting, respectively.

Results

Two rabbits in the VP group died of lung infection and cerebral infarction respectively at 1 week after plaque injury by liquid nitrogen. Both H&E and Masson staining revealed that the plaques from the SP and MSC groups had more stable morphological structure and a larger fibrous cap/lipid core ratio than the VP group. Serum hs-CRP, TNF-α and IL-6 were significantly down-regulated, whereas IL-10 was significantly up-regulated in the MSC group compared with the VP group. .Immunohistochemistry analysis revealed that NF-κB and MMP expression was reduced in the MSC and SP groups compared to the VP group. Cell apoptosis decreased significantly in both the MSC and SP groups in comparison to the VP group. TSG-6 mRNA and protein expression were higher in the plaques of the MSC group compared to the VP and SP groups.

Conclusions

Our study results suggest that MSC transplantation can effectively stabilize vulnerable plaques in atherosclerotic rabbits. This may potentially offer a new clinical application of MSC in atherosclerosis.     

Essential role of endothelial nitric oxide synthase for mobilization of stem and progenitor cells

Endothelial nitric oxide synthase (eNOS) is essential for neovascularization. Here we show that the impaired neovascularization in mice lacking eNOS is related to a defect in progenitor cell mobilization. Mice deficient in eNOS (Nos3(-/-)) show reduced vascular endothelial growth factor (VEGF)-induced mobilization of endothelial progenitor cells (EPCs) and increased mortality after myelosuppression. Intravenous infusion of wild-type progenitor cells, but not bone marrow transplantation, rescued the defective neovascularization of Nos3(-/-) mice in a model of hind-limb ischemia, suggesting that progenitor mobilization from the bone marrow is impaired in Nos3(-/-) mice. Mechanistically, matrix metalloproteinase-9 (MMP-9), which is required for stem cell mobilization, was reduced in the bone marrow of Nos3(-/-) mice. These findings indicate that eNOS expressed by bone marrow stromal cells influences recruitment of stem and progenitor cells. This may contribute to impaired regeneration processes in ischemic heart disease patients, who are characterized by a reduced systemic NO bioactivity.     

Mobilization of bone marrow stem cells with StemEnhance® improves muscle regeneration in cardiotoxin-induced muscle injury

Bone marrow-derived stem cells have the ability to migrate to sites of tissue damage and participate in tissue regeneration. The number of circulating stem cells has been shown to be a key parameter in this process. Therefore, stimulating the mobilization of bone marrow stem cells may accelerate tissue regeneration in various animal models of injury. In this study we investigated the effect of the bone marrow stem cells mobilizer StemEnhance (SE), a water-soluble extract of the cyanophyta Aphanizomenon flos-aquae (AFA), on hematopoietic recovery after myeloablation as well as recovery from cardiotoxin-induced injury of the anterior tibialis muscle in mice. Control and SE-treated female mice were irradiated, and then transplanted with GFP+ bone marrow stem cells and allowed to recover. Immediately after transplant, animals were gavaged daily with 300 mg/kg of SE in PBS or a PBS control. After hematopoietic recovery (23 days), mice were injected with cardiotoxin in the anterior tibialis muscle. Five weeks later, the anterior tibialis muscles were analyzed for incorporation of GFP+ bone marrow-derived cells using fluorescence imaging. SE significantly enhanced recovery from cardiotoxin-injury. However, StemEnhance did not affect the growth of the animal and did not affect hematopoietic recovery after myeloablation, when compared to control. This study suggests that inducing mobilization of stem cells from the bone marrow is a strategy for muscle regeneration.     

睾酮对雄兔hs-CRP、MMP-9、HO-1、APN和动脉粥样硬化斑块稳定性的影响

目的探讨睾酮对雄兔血高敏C反应蛋白（hs-CRP）、基质金属蛋白酶-9（MMP-9）、血红素氧化酶-1（HO-1）、脂联素（APN）和动脉粥样硬化斑块稳定性的影响。方法将66只雄性新西兰纯种兔随机分为4组,其中正常对照组10只（A组）、喂以普通饲料;假去势＋球囊损伤颈动脉组16只（B组）、去势＋球囊损伤颈动脉＋生理剂量睾酮（6mg/（kg.2周））肌注组16只（C组）、去势＋球囊损伤颈动脉＋生理盐水肌注组24只（D组）均喂以高脂饲料。在实验第8周随机抽取处死部分动物,观察颈动脉病变的形态特征,抽血测睾酮、hs-CRP、MMP-9、HO-1、APN水平。结果D组兔血睾酮水平显著降低;B,C组较D组兔血hs-CRP、MMP-9水平显著降低,HO-1、APN水平显著升高;且B,C组较D组兔动脉粥样斑块的面积和内-中膜厚度（IMT）显著减小,斑块纤维帽增厚、胶原含量明显增加。结论生理剂量睾酮可以影响雄兔血hs-CRP、MMP-9、HO-1、APN水平,并能调节动脉粥样硬化斑块进展与斑块的稳定性。     

SFRP5抑制BMP9诱导人脐带间充质干细胞成骨分化的实验研究

目的:探讨脂肪因子分泌型卷曲相关蛋白(secreted frizzled-related protein 5,SFRP5)对骨形态发生蛋白9(bone morphogenetic protein 9,BMP9)诱导人脐带间充质干细胞(human umbilical cord-derived mesenchymal stem cells,hUC-MSCs)成骨分化的影响。方法:将人脐带间充质干细胞根据不同的处理因素分为4组:对照组、BMP9组、BMP9+SFRP5组和SFRP5组;分别在3天、5天和7天进行碱性磷酸酶(alkaline phosphatase,ALP)活性读数,7天进行ALP染色,21天进行茜素红染色检测钙盐沉积及油红O染色;收集不同组的细胞用于裸鼠皮下注射成骨模型的建立,4周后取出离体骨进行Micro-CT扫描和分析,获取的标本进行HE、Masson染色,Alcian blue染色及油红O染色检测。Western blot检测成骨分化相关蛋白Runx2和OPN的表达。结果:BMP9组的ALP活性读数和染色结果和茜素红染色结果均较对照组增加,而BMP9+SFRP5组则较BMP9组降低;BMP9处理后出现少量脂滴,而BMP9+SFRP5组脂滴明显增加,SFRP5组脂滴最多;裸鼠皮下注射成骨模型的观察结果显示,对照组和SFRP5组没有形成肉眼可见的皮下包块,BMP9组和BMP9+SFRP5组能生成异位骨;4周后观测大体标本以及进行MicroCT检测,发现BMP9+SFRP5组的骨密度值小于BMP9组(P0.05)。HE、Masson染色,Alcian blue染色结果显示,BMP9组的骨分化程度大于BMP9+SFRP5,油红O染色结果示BMP9+SFRP5组有较多的成脂分化;SFRP5能抑制BMP9诱导的Runx2、OPN的蛋白质表达。结论:SFRP5抑制BMP9诱导的人脐带间充质干细胞成骨分化。     

Expanding expression of the 5-lipoxygenase/leukotriene B4 pathway in atherosclerotic lesions of diabetic patients promotes plaque instability

Emerging evidence now indicates that the 5-lipoxygenase (5-LO) pathway play a role in the pathogenesis of atherosclerosis and restenosis. The expression of 5-LO by activated macrophages in symptomatic plaques leads to leukotriene B(4) (LTB(4)) accumulation and enhanced synthesis and release of matrix metalloproteinases (MMPs) that can promote plaque rupture. However, the role of 5-LO pathway in diabetic vascular disease has not been previously reported. Thus, the present study was designed to analyze the expression of 5-LO in carotid plaques of diabetic patients and to investigate the possible role of 5-LO pathway in the pathogenesis and progression of diabetic atherosclerosis. Atherosclerotic plaques from 60 patients undergoing carotid endarterectomy were divided into non-diabetic and diabetic group. Plaques were analyzed for 5-LO, MMP-2 and MMP-9 by immunohistochemical, Western blot, and densitometric analyses, whereas zymography was used to detect MMP activity. Immunocytochemistry was also used to identify CD68+macrophages, CD3+T-lymphocytes, and HLA-DR+inflammatory cells. LTB(4) were quantified by enzyme-linked immunosorbent assay. 5-LO showed abundant immunoreactivity in human atherosclerotic carotid lesions, and was colocalized with macrophage infiltrates in atherosclerotic intima. 5-LO expression was higher in diabetic compared with non-diabetic plaques and was associated with increased MMP-2 and MMP-9 expression. Follow-up analyze with zymography assay revealed MMP activity was elevated in diabetic compared with non-diabetic plaques. Notably, in contrast to non-diabetic plaques, LTB(4) levels were significantly increased in diabetic plaques by enzyme-linked immunosorbent assay. These results suggest that overexpression of 5-LO and LTB(4) in atherosclerotic plaques possibly promote MMP-induced plaque rupture in diabetes. Hence, anti-LTs may be useful, not only in reducing atherogenesis, but also in the prevention and treatment of acute atherothrombotic events in diabetic patients.     

Mobilizing of haematopoietic stem cells to ischemic myocardium by plasmid mediated stromal-cell-derived factor-1alpha (SDF-1alpha) treatment

A concentration gradient of stromal-cell-derived factor-1alpha (SDF-1alpha) is the major mechanism for homing of haematopoietic stem cells (HSCs) in bone marrow. We tested the hypothesis that a gene therapy using SDF-1alpha can enhance HSCs recruiting to the heart upon myocardial infarction (MI). Adult mice with surgically induced myocardial ischemia were injected intramyocardially with either saline (n=12) or SDF-1alpha plasmid (n=12) in 50 microl volume in the ischemic border zone of the infarcted heart 2 weeks after myocardial infarction. Donor Lin-c-kit+ HSCs from isogenic BalB/c mice were harvested, sorted through magnetic cell sorting (MACS) and labeled with PKH26 Red. Three days after plasmid or saline injection, 1x10(5) labeled cells were injected intravenously (i.v.) into saline mice (n=4) and SDF-1alpha plasmid mice (n=4). The hearts and other tissue were removed for Western blot assay 2 weeks after plasmid or saline treatment. The labeled Lin-c-kit+ cells were identified with immunofluoresent staining and endogenous c-kit+ cells were identified by immunohistochemical staining. In mice killed at 1 month postinfarct, Western blot showed higher levels of SDF-1alpha expression in SDF-1alpha-treated mouse ischemic hearts compared to saline-treated hearts and other tissues. In the SDF-1alpha plasmid-treated hearts, SDF-1alpha is overexpressed in the periinfarct zone. The labeled stem cells engrafted to the SDF-1alpha positive site in the myocardium. There was also evidence for endogenous stem cell recruiting. The density of c-kit+ cells in border zone, an index of endogenous stem cell mobilization, was significantly higher in the SDF-1alpha-treated group than in the saline group (14.63+/-1.068 cells/hpf vs. 11.31+/-0.65 cells/hpf, P=0.013) at 2 weeks after SDF-1alpha or saline treatment. Following myocardial infarction, treatment with SDF-1alpha recruits stem cells to damaged heart where they may have a role in repairing and regeneration. The gene therapy with an SDF-1alpha vector offers a promising therapeutic strategy for mobilizing stem cells to the ischemic myocardium.