小鼠骨髓干细胞参与肾小管上皮细胞更新的实验研究

目的：观察骨髓来源的干细胞能否分化成肾小管上皮细胞，深化对骨髓干细胞可塑性的认识。方法：绿色荧光蛋白标记的C57BL／6转基因小鼠提供骨髓，同种无荧光的C57BL／6小鼠经致死剂量7射线全身均匀照射后接受骨髓移植，分别在移植后第56d、84d处死，采用荧光组织化学、免疫组织化学等方法观察绿色荧光在骨髓移植小鼠肾脏肾小管的分布及数量，观察骨髓干细胞在无损伤的小鼠肾脏中的分化。结果：骨髓移植后56d、84d的小鼠肾小管中有少量绿色荧光蛋白阳性细胞存在。激光共聚焦显微镜进一步证实这些细胞位于肾小管，并表达肾小管上皮细胞特异性的功能蛋白megalin。结论：骨髓干细胞可能参与肾小管上皮细胞的更新。     

骨髓干细胞转分化为肾祖细胞并参与修复急性肾脏损伤的研究

目的 观察骨髓干细胞是否可以向肾祖细胞转分化,成为肾脏祖细胞库的肾外来源;验证粒细胞集落刺激因子(G-CSF)是否可以促进骨髓干细胞向肾脏祖细胞的转分化,提高肾脏修复的效能.方法 6周龄全身表达绿色荧光蛋白(GFP)的C57BL/6J转基因小鼠提供骨髓,6~8周龄同种无荧光标记的C57BL/6J小鼠40只作为骨髓受体.骨髓移植前,受体小鼠接受致死剂量的γ放射线137Cs照射,骨髓重建情况经流式细胞仪检测确认.骨髓重建完毕后所有小鼠均接受单侧肾脏缺血再灌注损伤.干细胞动员效果及向肾脏归巢情况经流式细胞仪检测鉴定.损伤4、8周后取肾脏标本行免疫荧光组织化学染色,观察骨髓来源的肾脏祖细胞数以及骨髓细胞在微血管形成中的作用.损伤4周后通过组织切片免疫荧光组织化学方法观察并计数微血管细胞数.结果 G-CSF动员1 d后,分别为CD29、CD34、Sca-1、c-Kit、Flk-1阳性的干细胞占外周血非红系细胞的比例均高于对照组(P<0.05).损伤4周后,G-CSF动员组的肾脏中,骨髓来源并且分别表达Sca-1/GFP、CD29/GFP的干细胞的比例均高于对照组(P<0.05);在损伤4周及8周后,肾脏切片免疫荧光组织化学显示G-CSF动员肾脏中骨髓来源的肾祖细胞即Sca-1/GFP双阳性的细胞数量高于对照组.损伤4周后,动员组肾脏中表达CD31的微血管密度高于对照组(P<0.05).损伤4周后肾脏组织中存在CD105/GFP及α-SMA/GFP双阳性的细胞.结论 ①骨髓干细胞可以转分化为器官特异性干细胞-肾脏祖细胞;②G-CSF可以加速这一转分化的过程,并使损伤肾脏得到更好的修复.     

骨髓间质干细胞对大鼠急性肾小管损伤修复的促进作用

目的 观察骨髓间质干细胞(MSCs)对氯化汞(HgCl2)导致的急性肾小管损伤有无治疗作用，并探讨其可能的机制。 方法 建立HgCl2腹腔注射导致大鼠急性肾衰竭模型。SD大鼠分为MSCs组(HgCl2+MSCs)、生理盐水组(HgCl2+生理盐水)及正常对照组。7 d后，观察体重、生存率、肾功能、肾脏病理改变，进行增殖细胞核抗原(PCNA)、巨噬细胞标志物ED-1和增强绿色荧光融合蛋白(EGFP)免疫组织化学染色，用RT-PCR技术检测肾组织内细胞因子的表达情况，并观察EGFP转基因的MSCs在肾脏的分布情况。 结果 MSCs组在体重、生存率、肾功能、肾脏病理改变上，均明显好于生理盐水组；肾组织内PCNA+及ED-1+细胞数明显少于生理盐水组；促进肾小管损伤修复的生长因子表皮生长因子(EGF)、血小板源生长因子(PDGF)、肝细胞生长因子(HGF)在肾组织内表达明显高于生理盐水组，而促炎症因子TNF-α则明显低于生理盐水组。7 d时，间质干细胞在肾间质中偶尔可见到，而肾小管中未见。 结论 MSCs输注可促进HgCl2所致的急性肾小管损伤的修复，其作用机制可能是通过调节肾组织中细胞因子的分泌起作用，而非完全依靠转分化成肾小管上皮细胞。     

骨髓来源细胞移植对实验性肾小球肾炎小鼠的作用

目的：利用骨髓移植的方法观察骨髓来源细胞在小鼠实验性肾小球肾炎中的作用。方法：以绿色荧光蛋白（GFP）标记的C57BL／6转基因小鼠为供体,同种无标记小鼠为受体鼠,受体鼠在接受供体骨髓细胞前经亚致死剂量^60Co照射。并于移植5周后以尾静脉注射的方式接受竹叶青蛇毒注射;蛇毒注射后7、14、28、56d利用免疫组织化学和免疫荧光双重染色方法观察受体鼠肾脏内的GFP阳性细胞及受体鼠肾脏病理变化,其中一组受体鼠在蛇毒注射后接受连续1周的粒巨系一集落刺激因子（GM-CSF）腹腔注射,观察GM-CSF对骨髓来源细胞及受体鼠的影响。结果：无论有无蛇毒损伤,荧光显微镜下受体鼠肾脏内均未见明亮的绿色荧光。GFP免疫组织化学可见所有受体鼠的肾小管上皮内均有少量细胞质棕褐色、细胞核大且紫蓝的GFP阳性细胞,包括那些骨髓移植后无蛇毒损伤的受体鼠;肾小球内也可见上述细胞,但在无蛇毒损伤的受体鼠内肾小球内未见上述细胞;激光共聚焦显微镜未见到明显双染色阳性的细胞,从形态上证实肾小球内的这些GFP阳性细胞大多为血细胞。那些接受GM-CSF注射的受体鼠肾脏内,GFP阳性细胞没有明显增加,而且肾脏损伤恶化,表现为蛇毒注射后1周出现了明显的局灶性节段性肾小球硬化。结论：骨髓来源细胞在蛇毒诱导的系膜增生型肾小球肾炎小鼠肾脏内向肾小管和肾小球细胞均可少量转化,但由于转化率低及肾小球结构的复杂性,向肾小球细胞的转化更加不易被识别;GM-CSF注射未能增加外源性骨髓细胞向肾脏实质细胞的转化而使受体鼠肾脏损伤恶化,于病程早期出现了局灶性节段性肾小球硬化。     

卡维地洛改善顺铂致肾小管上皮细胞凋亡

目的 观察顺铂致急性肾衰竭(ARF)中肾小管上皮细胞凋亡情况及卡维地洛(carvedilol)对其影响,并探讨其作用机制。方法 雄性Wistar大鼠随机分为盐水对照组、顺铂组、卡维地洛对照组、卡维地洛治疗组。测定BUN、Scr、尿乙酰氨基葡糖苷酶(NAG)、肾组织丙二醛(MDA)与超氧化物歧化酶(SOD)的含量。苏木素-伊红染色(HE)观察肾脏病理改变。原位缺口末端标记法(TUNEL)与DNA电泳观察肾小管上皮细胞的凋亡。Western印迹检测caspase-3的蛋白表达。结果 顺铂组大鼠BUN、Scr、尿NAG升高;肾脏病理改变加重;大量的肾小管上皮细胞凋亡; MDA含量增加,SOD活性降低;caspase-3的蛋白表达增加。上述指标在卡维地洛治疗组均得到改善,BUN从(58.33±19.93)降至(28.74±19.62)mmol/L;Scr从(425.56±97.96)降至(253.90±134.87)μmol/L;NAG从(224.77±75.86)降至(137.52±26.38)U/L;MDA从(18.13±7.01)降至(9.74±1.68)nmol/mg蛋白;SOD从(30.05±12.20)升至(64.67±20.64)U/mg蛋白;caspase-3的蛋白表达从1.94±0.73降至1.25±0.52;细胞凋亡从(42.5±12.6)%降至(23.7±8.4)%;肾组织病理损害也明显改善。结论 肾小管上皮细胞凋亡是顺铂致ARF的重要原因之一。卡维地洛能减轻顺铂的肾毒性,降低肾小管上皮细胞凋亡,其机制可能与减少活性氧(ROS)的产生,部分抑制了caspase依赖的凋亡途径有关。     

经诱导的绿色荧光蛋白转基因C57BL雄鼠脾细胞移植重建雌鼠造血功能研究

目的探讨雄性C57BL绿色荧光蛋白（GFP）鼠诱导的脾细胞移植对造血衰竭小鼠造血重建的作用。方法建立小鼠造血衰竭模型,移植鱼卵提取物诱导的雄性C57BL荧光鼠脾细胞,检测诱导后细胞的干细胞标志抗原表达;观察受体存活时间,检测外周血白细胞计数、外周血GFP阳性细胞,进行荧光原位杂交检测Y染色体;各组受体脾和肺切片观察GFP细胞分布。结果鱼卵提取物诱导的雄性C57BL荧光鼠脾细胞比未诱导的脾细胞表达更多的干细胞标志抗原。1×106个脾细胞经尾静脉回输经致死剂量照射的雌性小鼠,明显延长小鼠存活时问,提高小鼠外周血白细胞计数。诱导组受体外周血中检测到GFP阳性细胞,骨髓中检测出60％的细胞含Y染色体。诱导组受体脾和肺切片观察到GFP阳性细胞分布。结论鱼卵提取物诱导的小鼠脾细胞中含较多的多能干细胞,回输给造血衰竭小鼠能重建其造血功能。     

绿色荧光蛋白转基因小鼠脂肪干细胞治疗后肢缺血的实验研究

目的观察绿色荧光蛋白(GFP)转基因小鼠来源的脂肪干细胞(ADSCs)治疗小鼠后肢缺血的效果及其自身所带荧光标记的有效性。方法取4周龄GFP转基因小鼠的脂肪组织,消化获取GFP来源的脂肪干细胞(GFP-ADSCs),并用流式鉴定其表面的干细胞抗原。建立C57BL/6小鼠左后肢缺血模型并随机分成两组(每组16只):一组后肢缺血的肌肉组织内注射P3代的GFPADSCs 1×106个/100μl,对照组于同样部位注射100μl PBS。1个月后利用苏木素-伊红(HE)、免疫组织化学(IHC)及免疫荧光(IF)染色行CD31染色观察缺血肌肉组织内血管新生情况。结果1从GFP转基因小鼠的脂肪组织中可以获得大量GFP-ADSCs并表达干细胞表面抗原CD90及CD105;2 GFP-ADSCs被成功地诱导成脂成骨;3 GFP-ADSCs组总残肢恢复率显著高于PBS组(P0.05);4 1个月后GFP-ADSCs治疗组缺血的肌肉组织内IHC染色CD31可见较多的新生血管,其微血管密度数显著高于PBS组(P0.05);IF染色显示GFP-ADSCs治疗组的新生血管表达内皮细胞的特异性标记CD31和GFP,而PBS组则未见GFP绿色荧光表达。结论从GFP转基因小鼠的脂肪组织中可以获取大量的ADSCs,其能够促进小鼠后肢缺血肌肉组织内的血管新生,自带的GFP可以示踪ADSCs在受体内的存活、迁移及分化。     

缺血再灌注损伤后小鼠肾脏血管内皮生长因子C的表达

目的探讨小鼠肾缺血再灌注损伤模型中血管内皮生长因子C的表达变化及其意义。方法建立小鼠肾缺血再灌注损伤模型。雄性C57BL／6小鼠用无创性动脉夹夹闭左肾动脉,置于32℃温箱后1h松开血管夹,取出右肾。Sham组操作同上,但不夹闭左肾动脉。再灌注0,6,12,24,48h后处死小鼠,收集外周血及肾脏标本。测定血肌酐（SCr）和尿素氮（BUN）水平。HE染色观察Sham组和缺血再灌注24h组（IR24h组）肾脏病理学变化,免疫组织化学检测Sham组和IR24h组血管内皮生长因子C（vascularendothelialgrowthfactorC,VEGF-C）在肾脏的表达及分布,连续切片检测VEGF-C与其受体血管内皮生长因子受体3（VEGFR-3）的共定位。Westernblot检测缺血后不同灌注时间VEGF-C的表达变化。结果小鼠肾脏缺血再灌注损伤后,SCr和BUN水平上升,且随着再灌注时间的延长肾功能损伤逐渐加重,再灌注24h时肾功能损伤最明显,再灌注48h时肾功能已经有部分恢复。与Sham组比较,缺血再灌注24h肾脏组织肾小管管腔扩张,内有管型形成,肾小管上皮细胞肿胀坏死,空泡变性,刷状缘坏死脱落,并且伴有炎性细胞侵润,而肾小球未见明显病变。免疫组织化学结果显示,与Sham组比较,缺血再灌注24h肾脏VEGF-C及其受体VEGFR-3的表达均明显增加,二者存在着共定位现象,且主要表达在肾脏皮髓质交界处及髓质部的肾小管。Westernblot结果显示随着缺血后再灌注时间的延长,VEGF-C的表达增加。结论肾缺血再灌注损伤后存在肾脏VEGF-C的表达上升,且与其受体VEGFR-3的表达增加呈共定位,推测VEGF-C可能参与了肾脏缺血再灌注损伤。     

骨髓间充质干细胞对缺血再灌注损伤肾小管上皮细胞增殖和凋亡的影响

目的：探讨外源性骨髓间充质干细胞（MSCs）移植对缺血再灌注损伤（I/R）后肾小管上皮细胞增殖和凋亡的影响。方法：将雄性SD大鼠MSCs用DAPI标记后注入受体雌性SD大鼠体内。30只受体大鼠随机分为3组：假手术对照组（C组）、MSCs＋I/R组（M组）、DMEM-F12＋I/R组（D组）,每组10只。7d后观察肾功能,肾脏病理改变,采用原位末端标记法检测细胞凋亡指数,免疫组化法检测增殖细胞核抗原（PCNA）的表达,并观察DAPI标记的MSCs在受体大鼠肾脏的分布情况。结果：I/R后第7天,M组在肾功能、肾脏病理改变上,均明显好于D组;肾组织内PCNA＋细胞数和凋亡指数均低于D组。I/R后7d内未发现MSCs定位于肾组织中。结论：外源性MSCs可以促进I/R损伤后肾小管上皮细胞的增殖和减少细胞凋亡,从而有利于肾小管损伤的早期恢复。     

Smac/Diablo与X-连锁凋亡抑制蛋白在ATP耗竭再恢复诱导肾小管上皮细胞凋亡中的作用

目的 研究线粒体蛋白Smac/Diablo和细胞X-连锁凋亡抑制蛋白(XIAP)在ATP耗竭及再恢复导致肾小管上皮细胞凋亡中的作用和机制。 方法 应用代谢抑制剂暂时性阻断人肾小管上皮细胞(HK-2细胞)内ATP的生成,再换用含糖的培养液使细胞内ATP再恢复,诱导肾小管上皮细胞凋亡。应用Hoechst33342检测肾小管上皮细胞凋亡的发生。用间接免疫荧光检测Smac/Diablo在细胞内的分布。分别提取胞质蛋白和细胞总蛋白,以Western印迹检测胞质中Smac/Diablo、XIAP和活化半胱氨酸天冬氨酸蛋白酶3前体(pro-caspase-3)的蛋白水平。 结果 肾小管上皮细胞内ATP耗竭及再恢复时,Hoechst33342染色可见HK-2细胞核固缩和凋亡小体的形成;间接免疫荧光可见Smac/Diablo由线粒体释放至胞质;Western印迹可见胞质内Smac/Diablo的含量增多( P < 0.01);XIAP和pro-caspase 3的蛋白水平降低(P < 0.05)。 结论 肾小管上皮细胞内ATP耗竭及再恢复时,Smac/Diablo释放至胞质,XIAP蛋白水平降低,进而激活caspase 3,介导肾小管上皮细胞凋亡。     

Proliferation of bone marrow-derived cells contributes to regeneration after folic acid-induced acute tubular injury

Studies of tissue from recipients of bone marrow transplantation or organ allograft suggest that bone marrow-derived cells (BMDC) may differentiate into a variety of nonhematologic tissues, including renal tubular epithelium. The aims of this study were to examine whether BMDC contribute to recovery after acute renal injury and to assess the effects of cytokine mobilization on regeneration. Female mice (6 wk old) were lethally irradiated and transplanted with male bone marrow (BM) cells and later assigned into control, folic acid-treatment, and folic acid-treatment with granulocyte-colony stimulating factor (G-CSF), and control with G-CSF. Tritiated thymidine was given 1 h before death. Kidney sections were stained for a tubular epithelial marker, Y chromosome (in situ hybridization), periodic acid-Schiff staining, and subjected to autoradiography. Renal tubular epithelial cells in S-phase were scored as female (indigenous) or male (BM-derived). This is the first report to show that BMDC can respond by engrafting the renal tubules and undergo DNA synthesis after acute renal injury. BMDC contributed to the renal tubular epithelial cell population, although most (90%) renal tubular regeneration came from female indigenous cells. Some evidence was found for cell fusion between indigenous renal tubular cells and BMDC, but this was infrequent and the significance and consequences of cell fusion in the kidney are unresolved. G-CSF treatment nearly doubled the frequency of thymidine-labeled BM-derived tubular cells and might facilitate the recovery of renal tubular epithelium.     

Elevation of serum albumin levels in nagase analbuminemic rats by allogeneic bone marrow cell transplantation

We investigated the feasibility of correcting the congenital absence of albumin in Nagase analbuminemic rats (NARs) by allogeneic bone marrow cell transplantation (BMT). Seven-week-old male NARs were used as recipients, and 6- to 8-week-old male Sprague-Dawley (SD) rats were used as allograft donors. NARs were divided into three groups: a BMT group (n=10) in which bone marrow cells were infused into the liver; a hepatocyte transplantation (HCT) group (n=8) in which hepatocytes were transplanted into the liver, and a control group (n=8) in which PBS was injected into the portal vein. Serum albumin levels were measured as an indicator of the function of the grafted cells, and the phenotypic characteristics of the engrafted cells in the recipient's liver were assessed with immunohistochemical and immunofluorescence techniques. At 8 weeks after cell transplantation, the serum albumin levels of the BMT group and HCT group were significantly higher than in the control group. The hepatocyte-like cells derived from bone marrow cells expressed albumin in liver of the NARs. According to this result, bone marrow cells can differentiate into hepatocyte-like cells in vivo. The results show that BMT is an effective treatment for congenital analbuminemia in a rat model and suggest that allogeneic BMT can be used as an efficient therapy for hereditary metabolic diseases.     

Can bone marrow differentiate into renal cells?

A considerable plasticity of adult stem cells has been confirmed in a wide variety of tissues. In particular, the pluripotency of bone marrow-derived stem cells may influence the regeneration of injured tissues and may provide novel avenues in regenerative medicine. Bone marrow contains at least hematopoietic and mesenchymal stem cells, and both can differentiate into a wide range of differentiated cells. Side population (SP) cells, which are originally defined in bone marrow cells by high efflux of DNA-binding dye, seem to be a new class of multipotent stem cells. Irrespective of the approach used to obtain stem cells, the fates of marrow-derived cells following bone marrow transplantation can be traced by labeling donor cells with green fluorescence protein or by identifying donor Y chromosome in female recipients. So far, bone marrow-derived cells have been reported to differentiate into renal cells, including mesangial cells, endothelial cells, podocytes, and tubular cells in the kidney, although controversy exists. Further studies are required to address this issue. Cell therapy will be promising when we learn to control stem cells such as bone marrow-derived stem cells, embryonic stem cells, and resident stem cells in the kidney. Identification of factors that support stem cells or promote their differentiation should provide a relevant step towards cell therapy.     

Bone mineral density in pediatric transplant recipients

BACKGROUND: Reduced bone mass and fragility fractures are known complications after transplantation in adults. Far less is known about the skeletal effects of transplantation in children and adolescents. METHODS: This cross-sectional study examined the skeletal status of children (ages 9-18 years) who were at least 1 year post-cardiac (n=13), post-renal (n=8), or post-bone marrow (BMT; n=15) transplantation. Bone mass at total hip, femoral neck, spine (L2-4), and whole body (WB) was determined by dual energy x-ray absorptiometry and compared with age, sex, and ethnic-specific reference data. Standard deviations (z-scores) were calculated for both areal bone mineral density (BMD) and estimated volumetric bone density (bone mineral apparent density [BMAD]). RESULTS: Cardiac transplant patients had significantly lower BMD z-scores compared with the reference population at all skeletal sites. BMT recipients had significantly reduced BMD z-scores at total hip, spine, and WB. Kidney transplant patients had a significantly reduced WB BMD z-score only. Spine BMAD z-scores remained significantly reduced in cardiac and BMT subjects. Three of 36 patients had radiographic evidence of spinal fracture after transplantation. No correlation between steroid dosage and any measure of bone mass was observed. CONCLUSIONS: Cardiac and BMT recipients had reduced BMD at multiple skeletal sites, and renal transplant recipients had reduced WB BMD for age. Deficits in spine bone density persisted after correcting for small bone size using BMAD. Low bone density and the occurrence of vertebral fractures indicate that cardiac, renal, and bone marrow transplantation in children is associated with reduced bone health.     

Roles of bone marrow cells in glomerular diseases

Bone marrow transplantation (BMT) has been used as a tool to investigate various roles of bone marrow cells in glomerular diseases. BMT from IgA nephropathy-prone mice caused glomerular IgA deposition associated with increased circulating macromolecular IgA in normal recipients. Conversely, glomerular mesangial lesions of IgA nephropathy-prone mice were markedly diminished by BMT from normal donors, and the circulating levels of macromolecular IgA were also decreased in the recipients. These data suggest that IgA nephropathy may be a stem-cell disease. BMT clearly decreased the glomerular injuries in glomerular diseases other than murine IgA nephropathy. Theoretically, one mechanism underlying the therapeutic effect of BMT is the replacement of the recipients destructive immune cells with the donors bone marrow cells. Interestingly, when BMT was performed by using bone marrow cells of green fluorescent protein (GFP) transgenic mice to investigate the differentiation of bone marrow stem cells in recipients, it was revealed that bone marrow-derived cells differentiated into glomerular cells in mice receiving BMT. This result suggests an alternative mechanism, in that bone marrow cells not only replace harmful immune cells but that they also replenish injured glomerular cells in BMT recipients, which results in the repair of glomerular lesions after BMT. In addition, the glomerular remodeling could participate in maintaining glomerular homeostasis. If the mechanisms of glomerular remodeling are investigated, this could offer a new therapeutic strategy for the repair of glomerular injuries.     

Vascularized bone marrow transplantation model in rats as an alternative to conventional cellular bone marrow transplantation: preliminary results

The aim of the study was to follow the development of microchimerism after allogeneic vascularized bone marrow transplantation (VBMT) versus conventional bone marrow transplantation (BMT). In one group, a VBMT model consisted of donor Brown Norway rat hind limb heterotopic transplanted on recipient Lewis rats. An intravenous infusion of donor bone marrow cells in suspension equivalent to that grafted in the vascularized femur limb was administered intravenously to recipient rats in the second group. Cellular microchimerism was investigated in recipients of VBMT versus BMT. Donor-derived cells could be detected in VBMT recipients at 30 and 60 days but not in recipients of intravenous suspension of BMC. VBMT provides a theoretical alternative to conventional cellular bone marrow transplantation by addressing crucial clinical problems such as failure of engraftment or graft-versus-host disease.     

Hematopoietic stem cells contribute to the regeneration of renal tubules after renal ischemia-reperfusion injury in mice

Ischemia-reperfusion injury (I/R injury) is a common cause of acute renal failure. Recovery from I/R injury requires renal tubular regeneration. Hematopoietic stem cells (HSC) have been shown to be capable of differentiating into hepatocytes, cardiac myocytes, gastrointestinal epithelial cells, and vascular endothelial cells during tissue repair. The current study tested the hypothesis that murine HSC can contribute to the regeneration of renal tubular epithelial cells after I/R injury. HSC isolated from male Rosa26 mice that express beta-galactosidase constitutively were transplanted into female nontransgenic mice after unilateral renal I/R injury. Four weeks after HSC transplantation, beta-galactosidase-positive cells were detected in renal tubules of the recipients by X-Gal staining. PCR analysis of the male-specific Sry gene and Y chromosome fluorescence in situ hybridization confirmed the presence of male-derived cells in the kidneys of female recipients. Antibody co-staining showed that beta-galactosidase was primarily expressed in renal proximal tubules. This is the first report to show that HSC can differentiate into renal tubular cells after I/R injury. Because of their availability, HSC may be useful for cell replacement therapy of acute renal failure.     

The potential of bone marrow-derived cells to differentiate to glomerular mesangial cells.

Bone marrow stem cells (BMC) develop into hematopoietic and mesenchymal lineages but have not been known to differentiate into glomerular cells. To investigate whether such differentiation is possible, a search was made for donor glomerular cells in lethally irradiated C57BL/6j (B6) mice given transplants of BMC from syngeneic mice transgenic for green fluorescence protein (GFP) ([GFP-->B6] mice). After the recipients of donor BMC manifested GFP-positive cells in their glomeruli, the numbers of such cells increased markedly, in a time-dependent manner, from 2 wk to 24 wk after bone marrow transplantation. Immunohistochemical analyses revealed that most GFP-positive cells in the glomeruli were neither macrophages nor T cells. With the use of a laser-scanning confocal microscope, GFP-positive cells were observed within the mesangium of [GFP-->B6] mice. Furthermore, indirect immunofluorescence assays demonstrated that desmin-positive cells in the glomeruli of these chimeric mice were also positive for GFP. Among glomerular cells isolated from [GFP-->B6] mice 24 wk after bone marrow transplantation and then cultured, the majority of cells (approximately 84%) stained for desmin and approximately 60% of the desmin-positive cells expressed GFP. In addition, these GFP-positive cells in the cultures contracted in response to angiotensin II stimulation. These results suggest that bone marrow-derived cells may have the potential to differentiate into glomerular mesangial cells.     

Antileukemic effect of interleukin-7-transduced bone marrow stromal cells in mice following allogeneic T-cell-depleted bone marrow transplantation

Impaired immune reconstitution following allogeneic bone marrow transplantation (BMT) remains a major obstacle to its clinical application. In this study, interleukin (IL)-7-transduced bone marrow stromal cells (MSC-IL7, 1 × 10⁶/mouse) were transfused into lethally irradiated C57BL/6 recipient mice. By day 40 after transplantation, the recipient mice were challenged with the lymphoma cell line EL4. MSC-IL7 cotransplantation protected recipient mice from leukemic mortality (MST >120 days after BMT vs mean survival time (MST) 70 days in the PBS group) It enhance the PFC count and DTH responses of recipients after transplantation. In conclusion, MSC mediated IL-7 gene therapy and may be a more feasible strategy to restore immune function following allo-TCD-BMT.