骨髓间充质干细胞对大鼠急性肾损伤的修复作用

目的：观察外源性骨髓间充质干细胞（Mesenchymal stem cells,MSCs）对庆大霉素（Gentamycin,GM）诱导的大鼠急性肾损伤是否具有治疗作用,并初探其机制。方法：建立腹腔注射庆大霉素致大鼠急性肾损伤模型。实验分为舡常对照组、模型组、MSCs治疗组（模型＋MSCs）、生理盐水组（模型＋生理盐水）。于不同处理后4d分别检测血尿素氮（BUN）和肌酐（Scr）水平,观察肾组织病理改变,免疫印迹及RT-PCR法检测肾组织肝细胞生长因子（Hepatocyte growth factor,HGF）水平。结果：模型组大鼠的BUN及Scr较正常对照组显著升高,且肾小管组织病理损伤严重;而MSCs治疗组大鼠的BUN及Scr水平较生理盐水组显著降低,肾小管组织病理损伤明显减轻。此外。促肾小管损伤修复的肝细胞生长因子（HGF）表达在MSCs治疗组显著高于生理盐水组。结论：MSCs输注可促进庆大霉素所致急性肾小管损伤的修复,改善肾功能,其作用机制可能是与上调肾组织中肝细胞细胞生长因子的表达有关。     

应用超声微泡在感染性休克致急性肾损伤中的作用

为了探讨超声微泡在感染性休克致急性肾损伤中的作用。本研究选取健康雄性8周龄SD大鼠45只,随机分为假手术组、模型组和超声微泡组,每组15只,其中模型组和超声微泡组大鼠建立感染性休克致急性肾损伤模型,超声微泡组给予1.0 W/cm2超声辐照处理,采用全自动生化分析以检测血肌酐(Scr)、内生肌酐清除率(Ccr)和尿酸氮(BUN),HE染色观察肾组织形态,免疫组化法观察细胞间黏附分子-1(ICAM-1)和单核细胞趋化蛋白-1(MCP-1)蛋白表达,Western blotting检测肝细胞生长因子(HGF)和表皮生长因子(EGF)蛋白表达。发现模型组和超声微泡组Scr和BUN明显高于假手术组(p0.05),而Ccr明显低于假手术组(p0.05);超声微泡组Scr和BUN值较模型组有所降低(p0.05),而Ccr值较模型组有所上升(p0.05);模型组和超声微泡组HGF和EGF蛋白明显低于假手术组(p0.05);超声微泡组HGF和EGF蛋白表达分别为(0.398±0.054)和(0.454±0.040),较模型组有所上升(p0.05);假手术组肾脏组织ICAM-1、MCP-1蛋白无表达,模型组ICAM-1、MCP-1蛋白表达明显,而超声微泡组ICAM-1、MCP-1蛋白表达较模型组有所减弱。说明超声微泡对感染性休克致急性肾损伤有改善作用,可降低肾脏组织ICAM-1和MCP-1蛋白表达,抑制HGF和EGF蛋白的表达,因此本研究的各项指标均作为急性肾损伤早期诊断和术后检测的指标,为寻找准确有效的急性肾损伤治疗方案提供参考依据。     

携带人肝细胞生长因子重组质粒pUDK-HGF对大鼠肾纤维化的防治作用

目的:研究肝细胞生长因子(HGF)基因转导对庆大霉素诱导的大鼠肾纤维化损伤的防治效果。方法:以雄性Wistar大鼠腹腔注射硫酸庆大霉素注射液制备肾纤维化模型;实验分为正常对照组、肾纤维化模型组、HGF治疗组;造模后第30 d,HGF治疗组于左侧肾脏直接注射重组质粒pUDK-HGF注射液,模型组注射质粒pUDK,正常对照组只进行假手术;于造模后第60 d处死大鼠,评价HGF对血尿素氮、血肌酐、24 h尿蛋白、肾系数等肾功能指标的改善作用,并对肾纤维化进行组织学评价。结果:与正常对照组相比,模型组肾功能下降,肾系数(8.8±0.95 g/kg)、血尿素氮(9.4±2.61 mmol/L)、血肌酐(42±10.33μmol/L,P<0.05)及24 h尿蛋白定量(25.78±8.66 mg,P<0.05)升高;HGF治疗组对肾功能有所改善,可缓解肾纤维化的进展。此外,本实验表明,对已纤维化肾脏直接注射HGF基因,可促进肾间质血管再生,并进一步降低肾小管间质损伤积分。结论:将HGF基因靶向导入大鼠体内可有效防治肾纤维化。     

顺铂诱导肾损伤过程中肾皮质脂质过氧化的变化

目的:探讨顺铂肾损伤过程中肾皮质脂质过氧化与肾小管结构改变的关系.方法:雌性Wistar大鼠随机分为生理盐水组、顺铂Ⅰ组、顺铂Ⅱ组、顺铂Ⅲ组,均为尾静脉注射给药,每天一次,连续五天.第六天取血测肌酐(Scr)、尿素氮(BUN)含量,取肾皮质测丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、谷胱甘肽过氧化物酶(GSH-Px)活性,同时进行肾小管上皮细胞碱性磷酸酶组织化学染色和组织病理学观察.结果:顺铂组Scr、BUN明显升高,肾皮质MDA含量升高,SOD与GSH-Px活性降低,与对照组相比均有显著差异(P＜0.05),且肾皮质SOD活性、GSH-Px活性与Scr、BUN含量呈明显负相关(P＜0.05),肾皮质MDA含量与Scr、BUN含量呈明显正相关(P＜0.05).酶组化显示肾小管上皮细胞碱性磷酸酶大量丢失,病理切片结果显示肾皮质部分肾小管上皮细胞变性、坏死.结论:顺铂引起肾皮质组织的破坏与肾皮质脂质过氧化增强有关,且随剂量增加肾皮质损伤加重.     

肝细胞生长因子在损伤肾组织中的作用

肝细胞生长因子（hepatocyte growth factor．HGF）是一种多效性生长因子,主要由间质细胞产生,通过自分泌和旁分泌方式作用于上皮细胞、内皮细胞以及间质细胞本身,具有促有丝分裂、促细胞形态形成和调节细胞活动的功能,从而对损伤的器官和组织进行修复。许多新的研究显示,在急性肾损伤时给予外源性HGF可以保护肾小管上皮细胞、重建肾小管结构和维持肾功能完整性。此外,HGF还能有效地抑制与慢性肾脏疾病及慢性肾功能衰竭密切相关的肾间质纤维化的进展过程。     

刺五加注射液预处理对大鼠肾缺血再灌注损伤的影响

该研究探讨了刺五加(Acanthopanax senticosus,AS)注射液预处理对大鼠肾缺血再灌注损伤(ischemic reperfusion injury,IRI)的保护作用及其可能机制。采取单动脉夹闭法建立大鼠肾缺血再灌注损伤模型。检测各组大鼠血清肌酐(Scr)、尿素氮(blood urea nitrogen,BUN)、丙二醛(malondialdehyde,MDA)、血液中白介素-6(interleukin-6,IL-6)、尿液肾损伤分子-1(kidney injury molecule-1,KIM-1)、6-乙酰-B-D-氨基葡萄糖苷酶(6-acetyl-B-D-glucosaminidase,NAG)的含量。苏木精–伊红染色(hematoxylin-eosin staining,HE)光镜下观察各组大鼠肾组织的病理变化。免疫组化法测定各组大鼠肾组织中细胞间黏附分子-1(intercellular adhesion molecule-1,ICAM-1)蛋白质水平。结果表明,HE染色光镜下观察,IRI组及AS组肾组织出现病理改变,对照组无明显病理变化,而AS组大鼠肾组织损伤较IRI组减轻。AS预处理大鼠肾IRI,可明显降低血清Scr、BUN、MDA、IL-6、尿液KIM-1、NAG量及肾组织中ICAM-1蛋白的表达。认为AS预处理对大鼠急性肾IRI具有明显保护作用,可能与其可以减轻大鼠IRI的炎性损伤反应有关。     

骨髓间充质干细胞对移植肾缺血再灌注损伤保护作用的实验研究

目的 观察骨髓间充质干细胞（MSCs）对移植肾缺血再灌注损伤（IRI）模型修复的保护作用,及其作用机制的思路。方法 （1）采用密度梯度离心法结合贴壁分离法分离培养纯化SD大鼠骨髓MSCs,观察其形态,流式细胞仪检测细胞表面标记,检测骨髓MSCs向成骨和成脂细胞分化的潜能;（2）成年雌性SD大鼠28只,随机分组：正常对照组（control group,n=6）,假手术对照组（sham-operated group,n=6）,移植肾IRI组（vehicle-treated I/R group,n=8）,经尾静脉输注间充质干细胞（MSCs）移植肾IRI组（MSCs-treated via tail vein I/R group,n=8）。检测肾功能指标血尿素氮（BUN）和肌酐（Cr）水平变化,评定肾小管的凋亡指数和增殖指数,测定肾组织起氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）活性及微量丙二醛（MDA）水平,以及对肾脏病理学变化进行观察。结果 （1）分离培养的骨髓MSCs纯度高、生物学特征稳定;（2）移植肾IRI组肾功能指标（BUN36.9±4.8,Scr279.9±22.6）、氧化应激指标明显升高,组织形态学出现肾间质水肿明显,肾小管上皮细胞空泡样变性,近曲小管管壁肿胀,管腔变小。而经尾静脉输注MSCs移植肾IRI组大鼠肾功能指标（BUN22.6±7.8,Scr223.6±26.7）和氧化应激指标得到明显改善（P〈0.05）,组织形态学肾小管上皮细胞细胞核固缩、碎裂和溶解等细胞坏死和变性征象明显减轻,肾小管上皮细胞增殖指数（PI）高于IRI组,肾小管上皮细胞凋亡指数（AI）低于IRI组,两组间差异有统计学意义（P〈0.05）。结论 骨髓MSCs输注能促进肾脏IRI损伤后肾脏细胞增殖,抑制肾脏细胞凋亡,降低血清Creatinine和BUN,在一定程度上促进IRI后肾功能的恢复,通过抑制氧自由基的生成减轻肾组织的损伤程度,改善肾功能。     

人脐带间充质干细胞对低氧环境下的肾小管上皮细胞中肝细胞生长因子（HGF）表达的影响

目的：肾脏的急性缺血缺氧性损伤是泌尿外科常见病,以肾小管间质纤维化为主要病理特点,成体干细胞在急性肾脏损伤动物模型中可以促进肾脏结构修复、改善肾脏功能,肝细胞生长因子作为抗纤维化的主要生长因子,在成体干细胞干预的急性肾脏损伤动物模型实验中起重要作用,然而以往的研究对象主要以动物模型为主,成体干细胞对肝细胞生长因子的具体调节机制尚不清。本实验通过体外分离、培养人的脐带间充质干细胞,来干预离体低氧预处理后的大鼠近端肾小管上皮细胞,探讨在体外培养条件下人脐带间充质干细胞对低氧预处理大鼠近端肾小管上皮细胞肝细胞生长因子表达的影响,为今后研究间充质干细胞治疗肾功能损害提供可靠的理论依据。方法：采用贴壁培养的方法无菌条件下分离、培养、传代人脐带间充质干细胞。细胞融合达90％时更换无血清培养基（serum．fleemedium,SFM）培养24h,收集细胞上清液即为人脐带间充质干细胞条件培养基（conditionmedium,CM）;大鼠近端肾小管上皮细胞（tubularepithelialcells,TECs）于低氧环境处理1h后,随机分为对照组与CM干预组,分别培养24h和48h后检测TECs中大鼠肝细胞生长因子（hepatocytegrowthfactor,HGF）的mRNA水平、收集上清液测定大鼠HGF蛋白的含量,同时收集CM干预组中Oh,12h、24h、48h的上清液,测定其中人来源HGF蛋白的含量,并对TECs在CM干预24h和48h后行免疫组化定性人的HGF蛋白的表达。结果：在低氧预处理的培养环境下,CM干预组中,TECs中大鼠来源的HGFmRNA表达水平在24h和48h时明显高于对照组（P〈0．05）;上清液中大鼠HGF蛋白的含量在24h和48h,CM干预组显著高于对照组（P〈0．05）;上清液中人的HGF蛋白的含量随时间进行性增高,免疫组化染色显示在24h和48h大鼠TECs中能检测人的HGF蛋白的表达。结论：在低氧预处理的体外培养环境下,脐带间充质干细胞的条件培养基可以显著的上调大鼠自身的HGF水平,并可诱导大鼠TECs合成和分泌人的HGF蛋白,并为探究脐带间充质干细胞治疗肾功能损害提供可靠的理论依据。     

上调miR-200c通过抑制TGF-β1/Smad3通路减轻单侧输尿管梗阻小鼠肾纤维化

目的观察mi R-200c在单侧输尿管梗阻(unilateral ureteral obstruction,UUO)小鼠肾组织中的表达变化及其对UUO小鼠肾间质纤维化和TGF-β1/Smad3通路的影响。方法 45只C57BL/6J小鼠,随机数字表法分为假UUO组、UUO组、UUO+agomi R-200c组,每组15只。假UUO组仅游离左侧输尿管但不结扎;UUO组和UUO+agomi R-200c组通过结扎左侧输尿管建立的肾纤维化模型,手术后第1、7、14d两组小鼠分别给予生理盐水和agomir-200c尾静脉注射。第21d后处死全部小鼠,取血测定血肌酐(Scr)、血尿素氮(BUN)。取小鼠梗阻侧肾脏组织,HE染色和Masson染色评价肾小管间质损伤和肾间质纤维化损伤程度,实时荧光定量PCR(q RT-PCR)检测肾组织mi R-200c的表达,Western blotting检测肾组织TGF-β1、Smad3及α平滑肌肌动蛋白(α-SMA)蛋白的表达。结果与假UUO组比较,UUO组小鼠肾组织mi R-200c的表达水平明显降低,血清Scr、BUN水平明显升高,肾小管间质损伤病理评分升高,肾胶原容积分数(c VF)增加,肾组织中TGF-β1、Smad3及α-SMA水平明显升高。与UUO组比较,UUO+agomi R-200c组小鼠肾组织mi R-200c的表达明显增高,血清Scr、BUN水平明显降低,肾小管间质损伤病理评分下降,肾胶原容积分数减少,肾组织中TGF-β1、Smad3及α-SMA水平明显降低。结论上调mi R-200c能够通过抑制TGF-β1/Smad3通路减轻UUO小鼠肾间质纤维化。     

Infusion of mesenchymal stem cells overexpressing GDNF ameliorates renal function in nephrotoxic serum nephritis

Nephrotoxic serum nephritis (NSN) is a well-established animal model of glomerulonephritis, a frequent clinical condition with a high mortality rate owing to the ineffectiveness of current therapies. Mesenchymal stem cells (MSCs) are adult stem cells with potential as novel therapies in regenerative medicine owing to the absence of allogenic rejection. Glial cell-derived neurotrophic factor (GDNF) acts as a morphogen in kidney development. The therapeutic effectiveness of bone marrow MSCs overexpressing GDNF (GDNF-MSCs) was evaluated in an NSN rat model. An adenoviral vector was used to transduce MSCs with GDNF and a green fluorescent protein reporter gene. Then, GDNF-MSCs were injected into NSN rats via the renal artery. The influence of GDNF on renal injury was assessed. The location of GDNF-MSCs in kidneys was detected using fluorescence microscopy, cells were counted, and kidney function was measured. Infusion of GNDF-MSCs enhanced the recovery of renal function in NSN rats. MSCs were detected in the kidney cortex after injection. Compared with control MSCs, GDNF-MSCs led to significantly better renal function and injury recovery in NSN rats. GDNF has a positive effect on MSC differentiation in renal tissue. Owing to their highly renoprotective capacity, GDNF-MSCs represent a possible novel cell-based paradigm for treatment of glomerulonephritis.     

Evaluation of the effect of autologous mesenchymal stem cell injection in a large-animal model of bilateral kidney ischaemia reperfusion injury

Objectives: Adult mesenchymal stem cells (MSC) have been proven to be of benefit to the kidney in different experimental models of renal injuries. All studies have been performed in valuable rodent models, but the relevance of these results to large mammals and ultimately, to humans remains unknown. Therefore, the aim of this study was to investigate the effect of MSC transplantation in an alternative ovine large-animal model of bilateral kidney ischaemia reperfusion injury.
Material and methods: Sheep were divided into three groups: one sham-operated group and two groups submitted to renal bilateral ischaemia for 60 min. Animals with ischaemia reperfusion injury were treated with injection of autologous MSCs or with vehicle medium.
Results: The model sheep presented with renal histological manefestations that closely resembled lesions seen in patients. Transplanted MSCs were found in glomeruli but not in tubules and did not express glomerular cell markers (podocin, von Willebrand factor), but functional evaluation showed no beneficial effect of MSC infusion. Morphological and molecular analyses corroborated the functional results. MSCs did not repair kidney parenchyma and failed to modulate cell death and proliferation or cytokine release (tumour necrosis factor-alpha, vascular endothelial growth factor alpha (VEGF-α), Bcl-2, caspase).
Conclusion: In this unique autologous large-animal model, MSCs did not exhibit reparative or paracrine protective properties.     

骨髓间充质干细胞移植在小鼠急性肾损伤肾内的存活与分化情况研究

为探讨急性肾损伤后,移植骨髓间充质干细胞(marrow mesenchymal stem cells,MSCs在损伤肾内的存活能力及分化情况,通过复苏、扩增培养已完成鉴定、经慢病毒EGFP转染的MSCs,观察备用MSCs的EGFP(enhanced green fluorescent protein)表达情况,采用雄性C57BL/6J小鼠12只建立小鼠肾脏缺血再灌注损伤模型后(结扎双侧肾蒂40 min后开放血流并经尾静脉注射MSCs),分别于第1、3、7、14 d处死3只小鼠,采集小鼠左侧肾脏制作石蜡切片,倒置荧光显微镜下观察MSCs在肾内的存活及分化情况,定量分析每个时间点存活于肾内的数目的差异.结果表明复苏、扩增培养出的MSCs增殖活力旺盛,成功建立小鼠肾脏缺血再灌注损伤模型.移植的细胞随时间的延长,存活于肾脏内的数量显著减少(第14 d存活于肾内的细胞数量仅为移植后第1d的1/5),第1、3、7、14 d表达EGFP的MSCs主要分布于肾小球周围、肾脏小血管内壁、肾小管与肾小管之间的间质而肾小管内壁未见到表达EGFP的MSCs分布.这说明移植的MSCs在缺血再灌注损伤后肾脏内能够存活,但肾脏内的微环境限制了移植细胞的存活能力.在肾小管内壁未观测到表达EGFP的MSCs,提示MSCs对肾脏修复的途径不是直接向肾小管内皮细胞分化而另有其它途径.     

CXCR4基因转染人脐带间充质干细胞移植治疗糖尿病肾病的实验研究

摘要 目的：探讨过表达CXCR4的人脐带间充质干细胞（human umbilical cord mesenchymal stem cell, hUC-MSCs）移植后对糖尿病肾病的治疗作用。方法：构建CXCR4的慢病毒表达载体，并建立过表达 CXCR4 的人脐带间充质干细胞（CXCR4-MSCs）。采用8周龄健康雌性SD大鼠75只，其中15只为正常对照组，60只为实验组。实验组糖尿病成模后一个月，将糖尿病实验大鼠60只随机分为4组：①移植CXCR4-MSCs组(CXCR4基因转染MSCs组)，即CXCR4组；②移植null-MSCs组(空质粒未转染CXCR4基因的MSCs组)，即null-MSCs；③移植MSCs组( MSCs组)；④PBS组(未移植任何的MSCs，单纯PBS注射，PBS组)。将CXCR4-MSCs、null-MSCs及MSCs消化离心，取含1×106个细胞悬液经尾静脉分别注入CXCR4-MSCs组、null-MSCs组及MSCs组大鼠体内，PBS组注射l mL PBS。干细胞治疗8周后，处死五组大鼠。各组大鼠处死前放代谢笼留取24 h尿，计算尿量，保存送检。处死前尾静脉采血检测血糖、称体重并记录。观察血糖、肾脏肥大指数、肾重、体重、24小时尿蛋白排泄量，并观察肾脏组织病理学改变。结果：60只SD雌性大鼠糖尿病模型成功率达100％，至实验8周糖尿病大鼠总共死亡14只，存活率达76.67％。实验开始后的8周，所有CXCR4组、Null-MSCs组、MSCs组、PBS组大鼠与正常组比较，体重均明显减轻(P<0.01)，血糖明显升高(P<0.01)。MSCs治疗后8周，除正常组外，其余各组大鼠血糖、肾重、肾重/体重比、24小时尿蛋白均显著增高，体重显著降低(P<0.05)；与PBS组相比，CXCR4组、null-MSCs组，MSCs组大鼠的肾重、肾重/体重比、24小时尿蛋白均明显降低(P<0.05)，体重无明显增加，血糖无明显降低(P>0.05)。CXCR4组大鼠的肾重、肾重/体重比、24小时尿蛋白较除正常组外的各组均明显降低(P<0.05)。糖尿病成模后，给予大鼠尾静脉注射干细胞悬液或等量培养液，注射后8周，除正常组外，其余各组PAS染色可见大鼠肾小球肥大，肾小球基底膜增厚、系膜增生、系膜基质增多，部分肾小球出现明显硬化，符合糖尿病肾病中期病理表现。CXCR4组大鼠肾小球系膜基质增生较其余各组大鼠减少(P<0.05)。结论：转染CXCR4的MSCs可改善糖尿病肾病。     

Jagged1 protein enhances the differentiation of mesenchymal stem cells into cardiomyocytes

BACKGROUND: Mesenchymal stem cells (MSCs) can differentiate into cardiomyocytes if an appropriate cellular environment is provided. Notch signals exchanged between neighboring cells through the Notch receptor can eventually dictate cell differentiation. In our study, we show that MSC differentiation into cardiomyocytes is dependent on the Notch signal. METHODS: We created a myocardial infarction model in rat by coronary ligation, administered direct intramyocardial injection of DAPI-labeled MSC immediately, and observed the differentiation of MSCs after 14 days by immunofluorescence staining against troponin T. We cultured MSCs and cardiomyocytes in four ways, respectively, in vitro. (1) MSCs cocultured with cardiomyocytes obtained from neonatal rat ventricles in a ratio of 1:10. (2) The two types of cells were cultured in two chambers separated by a semipermeable membrane as indirect coculture group. (3) Notch receptor-soluble jagged1 protein was added to indirect coculture group. (4) Both jagged1 protein and gamma-secretase inhibitor-DAPT were added to indirect coculture group. Two weeks later, we observed the differentiation percentage, respectively, by immunofluorescence staining. RESULTS: We found the differentiation of MSCs which were close to cardiomyocytes in vivo. The differentiation percentage of the four cell culture group was 30.13+/-2.16%, 12.52+/-1.18%, 26.33+/-2.20%, and 13.08+/-1.15%. CONCLUSIONS: MSCs can differentiate into cardiomyocytes in vitro and in vivo if a cardiomyocyte microenvironment is provided. 2. Cell-to-cell interaction is very important for the differentiation of MSCs into cardiomyocytes. 3. Jagged1 protein can activate Notch signal and enhance the differentiation of MSC into cardiomyocyte, while the effect can be inhibited by DAPT.     

二苯乙烯苷对糖尿病肾病大鼠氧化应激反应相关因子的影响

目的：探讨二苯乙烯苷（TSG）对糖尿病肾病（DN）大鼠氧化应激效应和肾功能的影响。方法：将雄性大鼠随机分为正常对照 组、DN 大鼠模型组和TSG 治疗组,采用腹腔注射链脲佐菌素（60 mg/kg）建立DN大鼠模型,给药8 周后所有大鼠称体重、肾重。 并且通过腹腔采血的方式,收集各组大鼠的血液,观察、测量各组大鼠血清中相应的生化指标,然后运用比色法测定各组大鼠血 清中氧化应激相关因子活性和含量。结果：TSG能够有效的增强肾脏对血肌酐、尿素氮的清除率,从而减轻由高血糖引起的肾脏 损伤,并且能够显著降低DN大鼠血液中NO、NOS含量,提高T-SOD、CAT 活力值。结论：二苯乙烯苷能够改善DN 大鼠血清中 相应的生化指标,有效抑制DN大鼠肾脏的氧化应激反应,对DN具有显著的治疗作用。     

Protective Effects of Mesenchymal Stem Cells with CXCR4 Up-Regulation in a Rat Renal Transplantation Model

The homing of mesenchymal stem cells to injured tissue, which is important for the correction of conditions such as ischemia-reperfusion injury (IRI) and immunolesions, has been performed previously, but with poor efficiency. Substantial improvements in engraftment are required to derive clinical benefits from MSC transplantation. Chemokines are the most important factors that control cellular migration. Stromal derived factor-1 (SDF-1) is up-regulated during tissue/organ ischemia damage, and its cognate receptor, chemokine receptor 4 (CXCR4), is involved in stem cell migration. The aim of our study was to investigate CXCR4 expression in MSCs and to validate both its role in mediating migration to transplanted kidneys and its immunoregulatory effects in renal protection. Specifically, the present study was designed to investigate the short-term tissue homing of MSCs carrying genetically modified CXCR4 in a rat renal transplantation model. We tested the hypothesis that MSCs with CXCR4 over-expression can more efficiently regulate immunological reactions. Lentiviral vectors were used to over-express CXCR4 or to introduce a short hairpin ribonucleic acid (shRNA) construct targeting endogenous CXCR4 in rat MSCs. MSCs were labeled with enhanced green fluorescent protein (eGFP). After cell sorting, recipient kidneys were regionally perfused; recipient animals were injected with transduced MSCs, native MSCs, or PBS via tail vein following renal transplantation; and the effects of MSC injection were observed.     

Bone marrow-derived mesenchymal stem cells ameliorate hepatic ischemia reperfusion injury in a rat model

Background

Ischemia-reperfusion (I/R) injury associated with living donor liver transplantation impairs liver graft regeneration. Mesenchymal stem cells (MSCs) are potential cell therapeutic targets for liver disease. In this study, we demonstrate the impact of MSCs against hepatic I/R injury and hepatectomy.

Methodology/Principal Findings

We used a new rat model in which major hepatectomy with I/R injury was performed. Male Lewis rats were separated into two groups: an MSC group given MSCs after reperfusion as treatment, and a Control group given phosphate-buffered saline after reperfusion as placebo. The results of liver function tests, pathologic changes in the liver, and the remnant liver regeneration rate were assessed. The fate of transplanted MSCs in the luciferase-expressing rats was examined by in vivo luminescent imaging. The MSC group showed peak luciferase activity of transplanted MSCs in the remnant liver 24 h after reperfusion, after which luciferase activity gradually declined. The elevation of serum alanine transaminase levels was significantly reduced by MSC injection. Histopathological findings showed that vacuolar change was lower in the MSC group compared to the Control group. In addition, a significantly lower percentage of TUNEL-positive cells was observed in the MSC group compared with the controls. Remnant liver regeneration rate was accelerated in the MSC group.

Conclusions/Significance

These data suggest that MSC transplantation provides trophic support to the I/R-injured liver by inhibiting hepatocellular apoptosis and by stimulating regeneration.