骨髓来源细胞向肺内迁移分化的实验研究

目的：观察骨髓来源细胞能否向肺内迁移及其特点。方法：野生型（257BL／6J雌性小鼠作为受体接受10Gy的射线照射后,经尾静脉植入同等背景的转增强型绿色荧光蛋白（EGFP）基因的C57BL／6J雄性小鼠（绿鼠）骨髓细胞1×10^7个／只。移植受体稳定1年后检测肺组织中EGFP的表达。结果：野生型小鼠肺组织中EGFP的表达率为0,绿鼠各组织中EGFP的表达率为100％。骨髓移植受体鼠肺组织有广泛的EGFP阳性细胞分布,主要分布在肺间质中,在支气管上皮、肺泡上皮中也有EGFP阳性细胞存在,表达率为100％,与野生型相比差异有显著性（P〈0．01）。结论：受放射线照射后的C57BL／6J小鼠,接受同种异基因小鼠骨髓来源细胞能向肺内迁移并分化为肺的组织细胞。     

供体骨髓来源干细胞在骨髓嵌合小鼠肠上皮中定植和分化研究

目的 观察骨髓移植后供体骨髓来源干细胞（bone marrow derived stem cells，BMDSCs）是否能够在受体肠上皮中定植并分化为肠上皮细胞。方法 使用密度为1．073g／mL的Percoll分离GFP转基因小鼠的骨髓有核细胞。利用^60Co放射源对C57BL／6小鼠进行10Gy致死剂量照射，照射后4h经尾静脉移植绿色荧光蛋白（green fluorescence protein，GFP）转基因小鼠骨髓细胞建立嵌合小鼠模型，移植后1月和6月取小肠标本石蜡包埋。使用GFP抗体鉴定GFP阳性供体细胞在小肠上皮的表达情况，并使用GFP抗体和细胞角蛋白（PCK）抗体进行双标以判断BMDSCs是否分化上皮细胞，同时结合绒毛蛋白（Villin）和GFP的免疫荧光双标及连续切片染色肠道特异转录因子CDX2和GFP来分析骨髓来源细胞是否分化为肠道功能性上皮细胞。结果供体骨髓来源细胞在嵌合鼠的骨髓和小肠上皮层中均有定植，且小肠上皮中GFP阳性细胞能够同时表达PCK、Villin和CDX2。结论 供体骨髓来源干细胞可以在骨髓嵌合小鼠的肠上皮定植，并分化为具有正常功能的小肠上皮细胞。     

骨髓间充质干细胞在小鼠肝脏局部分化为肝细胞的实验研究

目的 探讨小鼠骨髓间充质干细胞（bone marrow mesenchymal stem cells，BMSCs）在肝内分化为肝细胞的可行性。方法腹腔注射丙烯醇致雌性C57BL／6小鼠全肝损伤后局部接受雄性同品系绿色荧光蛋白（green fluorescence protein，GFP）转基因小鼠骨髓间充质干细胞移植。移植后3周取骨髓嵌合小鼠肝脏做冰冻切片，荧光显微镜下观察GFP阳性细胞在肝内分布，石蜡切片行GFP抗体和白蛋白（albumin，Alb）抗体免疫组化双标法检测GFP阳性细胞在受体小鼠肝内的分化情况。结果移植后3周小鼠肝内可见GFP阳性细胞，并可见GFP和Alb双阳性细胞。结论异体骨髓间充质干细胞可在小鼠肝内分化为表达Alb的肝细胞，为肝组织的再生和修复提供了新思路，显示了其在肝病治疗中的应用潜力。     

大鼠移植骨髓细胞向肝细胞转化的实验研究

目的 探讨体内骨髓细胞向肝细胞转化的可行性。方法 将雌性SD大鼠随机分为3组，每组15只。①R BMT(全身照射 骨髓移植)；②2—AAF R BMT；③2—AAF PH(部分肝切) BMT。进行交叉性别骨髓细胞移植，雄性骨髓植入雄性受体，分别于第5、10、20天处死雌鼠。以雄性性别决定基因sry作为细胞标记，用原位杂交和FISH作为检测方法对骨髓细胞的肝细胞转化进行分析。结果 PCR移植效果初步分析可见，R BMT组11例中有10例PCR阳性；2AAF PH BMT组11例中有7例阳性，2AAF B BMT组10例中有6例阳性。sry原位杂交染色发现，第5天各组雌性受体肝索中均未见sry阳性的肝细胞。第10天R BMT组可见1例sry阳性的细胞位于肝细胞索,FISH染色可见这一细胞白蛋白mRNA阳性。第20天各组PCR阳性各例均可在肝索中检测到sry阳性的细胞。FISH染色可见白蛋白mRNA阳性。经统计学分析第20天各组sry阳性细胞数无明显差异。结论 在B BMT、2—AAF PH BMT和2—AAF R BMT模型中移植的骨髓细胞均可以植入肝脏，并存在于肝细胞索。植入肝索的骨髓细胞最早可见于移植后第10天，并发生转分化，表达白蛋白mRNA。不经过全身照射的2—AAF PH BMT组，移植的骨髓细胞也可以进入肝脏发生转分化，因此全身照射并不一定是移植骨髓细胞活化、植入和转化的必须条件。     

大麻素Ⅱ型受体激动剂促进小鼠心肌梗死后心脏干／祖细胞增殖的作用

目的：探讨大麻素Ⅱ型受体（CB2）选择性激动剂AMl241对小鼠心肌梗死（MI）模型中心脏干／祖细胞增殖的作用。方法：40只雄性C57BL／6小鼠通过结扎小鼠心脏左冠状动脉前降支建立MI模型并随机分为4组,每组10只（n=10）：①假手术（Sham）组;②MI组;③MI＋CB：受体激动剂AMl241（MI＋AMl241）组;④MI＋CB2受体激动剂AMl241＋CB2受体拮抗剂AM630（MI＋AMl241＋AM630）组。采用小动物超声系统观察小鼠左室射血分数（LVEF）的变化。用免疫荧光染色法观察MI周边区表达干细胞生长因子受体（c-kit）、干细胞抗原1（Sea-1）的阳性细胞数,实时荧光定量PCR测定MI周边区c-kit、Sea-1和多药耐药蛋白P糖蛋白（MDRl）的表达水平。结果：与MI组相比,MI＋AMl241组小鼠7d和14d心脏LVEF值显著提高（P〈0．01）。免疫荧光染色的结果提示,MI＋AMl241组c-kit和Sea-1的表达较MI组增多（P〈0．05）。实时荧光定量PCR结果显示,MI＋AMl241组c-kit和Sea-1的基因表达水平明显高于MI组（P〈0．05）。同时,CB2受体拮抗剂AM630可阻断AMl241的上述作用。结论：CB2受体激活可促进梗死心肌干／祖细胞的增殖,改善心脏的收缩功能。     

实验性慢性肾缺血模型肾小管-间质细胞α-平滑肌肌动蛋白的表达和意义

目的：观察单侧肾动脉狭窄(RAS)大鼠模型慢性肾缺血组织中肾小管-间质α-平滑肌肌动蛋白(α-SMA)的表达和意义。方法：建立Goldblatt，单侧RAS大鼠模型，观察大鼠慢性缺血肾脏在90天内不同阶段的病理改变；应用免疫组化法检测肾小管-间质α-SMA及波形蛋白(vimentin)在不同时间点的表达：应用免疫荧光双标记激光共聚焦显微镜观察细胞角蛋白(cytokeratin，CK)与α-SMA在肾小管上皮细胞中的共定位情况。结果：RAS术后第5天首先出现肾小管vimentin阳性，术后第7天肾间质可见少量的α-SMA阳性细胞并随时间递增。通过连续切片观察到，vimentin阳性的肾小管周围肾间质细胞α-SMA表达增强，并与肾小管间质纤维化程度基本一致。当慢性缺血状态持续存在时，后期(术后第45天至90天)少数损伤的肾小管上皮细胞表达α-SMA。应用免疫荧光双标记激光共聚焦显微镜观察发现，部分α-SMA阳性的肾小管上皮细胞同时表达CK，并且个别细胞还有向间质游走的趋势。结论：在慢性肾缺血早期Vimentin阳性的。肾小管上皮细胞本身叮能诱导了肾间质固有细胞发生肌成纤维细胞转分化，参与肾间质纤维化的发生和发展；在慢性肾缺血后期，肾小管上皮细胞转分化可能是导致肾纤维化进行性发展的关键环节。     

Lck在狼疮肾炎肾小管上皮细胞中表达的研究

目的 观察狼疮肾炎病理过程中淋巴细胞特异性蛋白酪氨酸激酶（Lck）在肾小管上皮细胞内的表达及白细胞介素-2（IL-2）对其表达的影响。方法 体外培养6周龄BXSB狼疮小鼠的近端肾小管上皮细胞，给予IL-2刺激，采用反转录聚合酶链反应（RT—PCR）方法及免疫印迹法检测肾小管上皮细胞中Lck mRNA和蛋白的表达，观察IL-2对Lck表达水平的影响。同时用免疫组织化学方法观察Lck蛋白在狼疮肾炎小鼠和人类肾脏组织标本肾小管上皮细胞内的表达情况。结果 体外培养的6周龄BXSB狼疮小鼠近端肾小管上皮细胞中仅有微量LckmRNA及蛋白的表达，IL-2刺激后表达水平显著增加（P〈0．05）。免疫组织化学方法显示：正常BALB／C小鼠、未发病的狼疮小鼠和人类微小病变性肾病肾脏组织的肾小管上皮细胞内均未发现明显的Lck蛋白表达，而已发病的16周龄狼疮肾炎小鼠和人类Ⅳ型狼疮肾炎肾脏组织标本的肾小管上皮细胞内则有明显的Lck蛋白表达。结论 IL-2可活化肾小管上皮细胞并诱导Lck表达，Lck可能作为细胞因子或炎症因子的重要信号分子，在小管-间质性炎症及狼疮肾炎病理过程中发挥着重要作用。     

骨髓间充质干细胞向急性肾损伤小鼠的肾脏归巢现象及功能探讨

目的:观察在缺血再灌注(ischemia/reperfusion,I/R)模拟急性肾损伤的小鼠模型中,骨髓间充质干细胞(mesenchymal stem cells,MSCs)能否向损伤的肾小管迁移并促进其修复. 方法:Percoll密度梯度离心结合贴壁培养法有效分离纯化出C57BL/6小鼠的骨髓间充质干细胞(mMSCs),5-溴脱氧尿嘧啶核苷(BrdU)标记并采用免疫组化法鉴定.雄性C57BL/6小鼠45只,分为正常埘照组(15只)、I/R组(15只、夹闭双侧肾蒂30 min开放)、I/R+BrdU-mMSCs组(15只、夹闭双侧肾蒂30 min开放的同时尾静脉注射经BrdU标记的mMSCs).于建模后1d、2d、3d、7d、14d分别处死部分小鼠(每次每组均处死3只),留取动脉血及肾组织,检测血肌酐(SCr)及尿素氮(BUN)水平,观察肾组织病理变化,荧光组织化学及免疫组织化学观察MSCs在受体小鼠肾组织的分布并对其进行鉴定. 结果:经免疫组化证实BrdU标记mMSCs的阳性率可达(98.71±0.32)%.I/R组、I/R+Brdu-mMSCs组小鼠的BUN及SCr均显著高于正常对照组,但I/R+BrdU-mMSCs组小鼠的BUN及SCr水平却较同一时间点的I/R组为低,肾小管损伤程度评分也有着显著降低.免疫组化检测显示I/R+BrdU-mMSCs组小鼠肾脏中可检测到BrdU~+细胞的分布,以术后第3天最多[(19.36±6.94)%].经荧光组织化学及激光共聚焦显微镜观察证实该BrdU~+细胞定位于小鼠的肾小管上皮细胞(renal tubular epithelial cells,RTECs)处,且表达RTECs特异性的标志物角蛋白18(cytokertain-18,CK18). 结论:小鼠发生I/R诱导的急性肾损伤后可诱导MSCs向损伤的肾小管上皮迁移并转化,参与RTECs的更新,促进肾损伤的修复.     

抗氧化剂和内质网钙释放阻滞剂对老年大鼠肾脏缺血/再灌注损伤中凋亡的影响

目的 探讨联合应用抗氧化剂BHA（Butylated Hydroxyanisole,叔丁基羟基茴香醚）和内质网钙释放阻滞剂TMB-8[8-（N,N-diethylamino）-noctyl-3,4,5-trimethoxybenzoate）]对老年大鼠肾脏缺血/再灌注（I/R）损伤时肾组织中细胞凋亡蛋白酶-3（caspase-3）表达及活性的影响.方法 27月龄Wistar大鼠分别随机分为假手术组、I/R模型组、I/R＋BHA＋TMB-8组,双侧肾动脉夹闭30 min/再灌注18 h制作模型.观察肾功能改变,原位末端标记（TUNEL）法检测肾小管上皮细胞凋亡情况,Northern blot检测肾组织中caspase-3 mRNA表达,比色法测定肾组织中caspase-3活性.结果 肾脏I/R损伤时,老年大鼠肾功能明显减退,大量肾小管上皮细胞凋亡,肾组织caspase-3 mRNA表达及活性增加;BHA＋TMB-8能显著改善老年大鼠肾功能,减轻肾小管上皮细胞凋亡,降低肾组织caspase-3表达及活性.结论 BHA＋TMB-8联合治疗能明显抑制老年大鼠肾脏I/R损伤时肾组织caspase-3表达及活性,从而减轻肾小管上皮细胞凋亡,保护肾功能.     

舒洛地特对SUMO4介导的2型糖尿病大鼠肾脏的保护作用

目的：探讨舒洛地特对小泛素养修饰蛋白（SUMO）4介导的2型糖尿病大鼠肾脏功能的保护作用.方法：将20只GK大鼠按数字表法随机均分为糖尿病组（DM组）、舒洛地特治疗组（DM＋S组）,SPF级同龄雄性Wistar大鼠10只作为健康对照组,DM＋S组给予舒洛地特10mg· kg-1·d-1腹腔注射,连续8周,其余两组给予等体积生理盐水注射.分别于用药前1d和用药结束后次日测定24 h尿微量白蛋白量,光镜下观察肾脏组织的结构变化,免疫组化法检测三组大鼠肾脏组织中核转录因子-κB（NF-κB）、SUMO4、NF-κB抑制剂（IκB）的表达.结果：（1）用药前DM组与DM＋S组大鼠的血糖及24 h尿白蛋白排泄率显著高于健康对照组（P＜0.01）;用药后DM＋S组24 h尿白蛋白排泄率显著低于DM组[（146.90±10.92）％比（314.63±20.42）％,P＜0.01];（2）与健康对照组相比,光镜下GK大鼠的肾脏肾小球毛细血管球肥大,基底膜轻度增厚,肾小球系膜细胞增生、肥大,肾小管上皮细胞肥大.未见典型的结节性肾小球硬化,似为糖尿病肾损害的早期改变,DM＋S组肾脏组织病理改变较DM组明显减轻;（3）免疫组化示：DM＋S组和DM组SUMO4、NF-κB、IκB表达显著高于健康对照组;与DM组比较,DM＋S组SUMO4[（29.8±0.6）比（34.2±0.7）]、IκB[（25.5±0.7）比（37.3±0.6）]表达显著增加,NF-κB[（43.9±0.9）比（27.0±0.6）]表达显著减少,P均＜0.05.结论：（1）小泛素养修饰蛋白4、NF-κB抑制剂在糖尿病GK大鼠肾脏组织表达增多;（2）舒洛地特对糖尿病GK大鼠肾脏组织有一定的保护作用.     

Homing of the bone marrow-derived interstitial cells of Cajal is decreased in diabetic mouse intestine

Background: Interstitial cells of Cajal (ICCs), which express c‐Kit receptor tyrosine kinase (KIT), play an important role in gastrointestinal motility. Loss of ICCs likely contributes to diabetic gastrointestinal motility disorder, however, the mechanism of attrition remains unknown. Here, we test the hypothesis that the bone marrow‐derived progenitors are an important source of intestinal ICCs and that decreased homing of these progenitors in diabetes contributes to ICC diminution. Methods: Wild type mice were X‐ray irradiated, transplanted with bone marrow (BMT) from green fluorescence protein (GFP)‐transgenic (TG)‐mice and subsequently made diabetic by streptozotocin (STZ) injection. Intestinal homing of GFP‐positive bone marrow‐derived cells was examined 2 or 5 months after STZ treatment. Results: In the BMT‐mice, we found many GFP‐positive bone marrow‐derived cells (BMDCs) in most parts of the intestinal area, the number of BMDCs was significantly decreased in diabetic mice compared with nondiabetic controls. As a representative area, we further examined the myenteric plexus of the proximal small intestine, and found that the cell numbers of ICCs marked by c‐Kit‐positive immunoreactivity were decreased by more than 40% in diabetic versus nondiabetic mice. Furthermore, numbers of c‐Kit+/GFP+ and c‐Kit+/GFP‐ cells were similar in nondiabetic mice, and decreased by 45.8% and 42.0%, respectively, in diabetic mice. Conclusion: These results suggest that the decreased homing from the bone marrow is a major cause of ICC loss in the intestine in diabetes mellitus.     

Efficiency of bone marrow-derived cells in regeneration of the stomach after induction of ethanol-induced ulcers in rats

Background Bone marrow contains hematopoietic stem cells, nonhematopoietic mesenchymal stem cells, and several precursor cells for osteoblasts, chondrocytes, adipocytes, myocytes, hepatocytes, and even neural cells. Research findings indicate that multipotent stem cells in the adult body may be used to recover the lost functions of damaged tissues. This study examined the involvement of bone marrow-derived cells in the regeneration of the stomach after experimental gastric ulcers were produced in rats.Methods We transplanted the bone marrow of transgenic rats that expressed green fluorescence protein (GFP) throughout the body. Twenty-one days after the bone marrow transplantation (BMT), gastric ulceration was induced, using absolute ethanol. Control animals received saline. After various observation periods, rats harboring GFP-positive bone marrow-derived cells were killed, and the tissues were removed and processed to prepare paraffin-embedded sections. Cells expressing GFP were identified by conventional immunohistochemistry, using anti-GFP antibody. To identify whether cells expressing GFP were epithelial cells or interstitial cells such as fibroblasts, serial sections were examined with anti-cytokeratin antibody or anti-vimentin antibody, respectively. Furthermore, to confirm that cells expressing GFP were epithelial cells or interstitial cells, we used double-staining analysis with anti-GFP antibody or anti-cytokeratin antibody, respectively.Results GFP-positive, bone marrow-derived cells were found in the cytokeratin-positive gastrointestinal epithelium, as well as among vimentin-positive interstitial cells. Interestingly, the proportions of GFP-positive, cytokeratin-positive epithelial cells and vimentin-positive interstitial cells were significantly greater in the ethanol-treated damaged stomachs than in the saline-treated controls.Conclusions The present study clearly demonstrates that bone marrow-derived cells are involved in the regeneration of the stomach after ethanol-induced ulcers in rats.     

Increased life span and correction of metabolic defects in murine mucopolysaccharidosis type VII after syngeneic bone marrow transplantation

The gusmps/gusmps mouse has no beta-glucuronidase activity and develops murine mucopolysaccharidosis type VII (MPS VII). The clinical and pathologic abnormalities are similar to those found in humans with severe MPS VII. Mutant mice are dysmorphic, dwarfed, and have a shortened life span. Pathologic findings include widespread lysosomal storage. To determine whether bone marrow transplantation (BMT) corrects these abnormalities, genetically identical mutant animals were given syngeneic bone marrow transplants using cells from +/+ mice. Initial experiments showed that levels of beta-glucuronidase activity in recipient tissues correlated with the amount of radiation administered before BMT. Two groups of mice given BMT therapy were observed for periods of 1 and 2 years, respectively. These mice were evaluated using a combination of clinical, biochemical, histochemical, and pathologic analyses. Spleen, liver, cornea, and glomerular mesangial cells showed essentially complete correction at all radiation doses. Storage was partially corrected in meninges and perivascular cells in brain, and in renal tubular epithelial cells at the higher radiation doses. Life span in BMT-treated animals was increased approximately three-fold, approaching that seen in normal mice after BMT. These results support the position that BMT has a place in the therapeutic regimen for MPS VII.     

Bone marrow-derived cells contribute to pulmonary vascular remodeling in hypoxia-induced pulmonary hypertension

STUDY OBJECTIVE: In these days, it was reported that bone marrow (BM) cells might take part in the remodeling of some systemic vascular diseases; however, it remains unknown whether the BM cells were involved in the vascular remodeling of pulmonary arteries and the progression of pulmonary hypertension (PH). The purpose of this study was to investigate whether BM-derived cells contribute to pulmonary vascular remodeling in hypoxia-induced PH. MATERIALS AND METHODS: To investigate the role of BM-derived cells, we transplanted the whole BM of enhanced green fluorescent protein (GFP)-transgenic mice to the lethally irradiated syngeneic mice (n = 30). After 8 weeks, chimera mice were exposed to consistent hypoxia using a hypoxic chamber (10% O(2)) for up to 4 or 8 weeks (10 mice per group). After hemodynamics and the ratio of right ventricular (RV) weight to left ventricle (LV) weight, RV/(LV + septum [S]), were measured, histologic and immunofluorescent staining were performed. RESULTS: BM-transplanted mice showed a high chimerism (mean [+/- SEM], 91 +/- 2.3%). RV systolic pressure and the RV/(LV + S) ratio increased significantly with time in PH mice, indicating RV hypertrophy. Marked vascular remodeling including medial hypertrophy and adventitial proliferation was observed in the pulmonary arteries of PH mice. Strikingly, a number of GFP(+) cells were observed at the pulmonary arterial wall, including the adventitia, in hypoxia-induced PH mice, while very few cells were observed in the control mice. Metaspectrometer measurements using confocal laser scanning microscopy confirmed that this green fluorescence was produced by GFP, suggesting that these GFP(+) cells were mobilized from the BM. Most of them expressed alpha-smooth muscle actin, a smooth muscle cell, or myofibroblast phenotype, and contributed to the pulmonary vascular remodeling. A semiquantitative polymerase chain reaction of the GFP gene revealed that the BM-derived GFP-positive cells in the PH group were observed more than eightfold as often compared with the control mice. CONCLUSION: The BM-derived cells mobilize to the hypertensive pulmonary arteries and contribute to the pulmonary vascular remodeling in hypoxia-induced PH mice.     

The effect of bone marrow transplantation on the osteoblastic differentiation of human bone marrow stromal cells.

Osteoporosis is a serious and relatively common complication of transplantation procedures. However, little is known about the exact mechanism or severity of osteoporosis complicated by bone marrow transplantation (BMT). We conducted both ex vivo and clinical studies to identify the mechanism and extent of bone loss after BMT. In a prospective clinical study, we intended to identify the changes in bone turnover markers and bone mineral density (BMD) after BMT. During a 1-yr follow-up, BMD was measured before BMT and 1 yr after BMT in 67 patients undergoing BMT. Biochemical markers of bone formation and resorption were measured in all patients at short-term intervals during the yearlong follow-up. In ex vivo study, we cultured human bone marrow cells of normal controls and BMT recipients in osteogenic medium and compared their osteogenic potential. Using a DNA fingerprinting method, we also investigated the origin of bone marrow stromal cells that were harvested 3-4 wk after BMT. In a clinical study of 67 patients undergoing BMT, the mean serum carboxy-terminal cross-linked telopeptide of type I collagen increased progressively until 4 wk after BMT. Thereafter, it began to decrease and reached basal values after 1 yr. Serum osteocalcin decreased progressively until 3 wk after BMT and reached basal values after 3 months. One year after BMT, lumbar spine BMD had decreased by 3.3% (P < 0.05), and total proximal femoral BMD had decreased by 8.9% (P < 0.001). For the ex vivo study, bone marrow was obtained from healthy donors (n = 7) and transplant recipients (n = 7). Then, mononuclear cells including marrow stromal cells were isolated and cultured to osteoblastic lineage. Alkaline phosphatase activities of each group were measured by the time course of secondary culture, and the mineralizing potentials were compared between the two groups. Cells cultured in our system showed characteristics of osteoblast-like cells differentiated from marrow stromal cells. They were initially in a fibroblastic-like spindle shape and became cuboidal with the formation of nodules that were later confluent. The cells were stained to both alkaline phosphatase histochemistry and Von Kossa histochemistry, demonstrating that these cells were of osteoblastic lineage differentiating from marrow stromal cells. The mean time required for the near-confluence in the primary culture was 15 and 22.9 d in healthy donors and transplant recipients, respectively (P = 0.003). Alkaline phosphatase activity was significantly lower in the bone marrow recipients than in the healthy donors at d 7 and 10 of the secondary cultures. The period at which peak activity of alkaline phosphatase was reached was also delayed in the osteoblasts derived from BMT recipient bone marrow compared with those of healthy donors. Using Von Kossa histochemistry, much more mineralization was observed in osteoblasts of healthy donors than those of BMT recipients. After BMT, although the peripheral mononuclear cells in the recipients were of donor origin, the bone marrow stromal cells were of recipient origin according to the PCR analysis using YNZ 22 mini-satellite probe. In conclusion, the differentiation of bone marrow stromal cells into osteoblasts was impaired after BMT, and this might contribute to post-BMT bone loss.     

Bone marrow production of lung cells: the impact of G-CSF, cardiotoxin, graded doses of irradiation, and subpopulation phenotype

OBJECTIVE: Previous studies have demonstrated the production of various types of lung cells from marrow cells under diverse experimental conditions. Our aim was to identify some of the variables that influence conversion in the lung. METHODS: In separate experiments, mice received various doses of total-body irradiation followed by transplantation with whole bone marrow or various subpopulations of marrow cells (Lin(-/+), c-kit(-/+), Sca-1(-/+)) from GFP(+) (C57BL/6-TgN[ACTbEGFP]1Osb) mice. Some were given intramuscular cardiotoxin and/or mobilized with granulocyte colony-stimulating factor (G-CSF). RESULTS: The production of pulmonary epithelial cells from engrafted bone marrow was established utilizing green fluorescent protein (GFP) antibody labeling to rule out autofluorescence and deconvolution microscopy to establish the colocaliztion of GFP and cytokeratin and the absence of CD45 in lung samples after transplantation. More donor-derived lung cells (GFP(+)/CD45(-)) were seen with increasing doses of radiation (5.43% of all lung cells, 1200 cGy). In the 900-cGy group, 61.43% of GFP(+)/CD45(-) cells were also cytokeratin(+). Mobilization further increased GFP(+)/CD45(-) cells to 7.88% in radiation-injured mice. Up to 1.67% of lung cells were GFP(+)/CD45(-) in radiation-injured mice transplanted with Lin(-), c-kit(+), or Sca-1(+) marrow cells. Lin(+), c-kit(-), and Sca-1(-) subpopulations did not significantly engraft the lung. CONCLUSIONS: We have established that marrow cells are capable of producing pulmonary epithelial cells and identified radiation dose and G-CSF mobilization as variables influencing the production of lung cells from marrow cells. Furthermore, the putative lung cell-producing marrow cell has the phenotype of a hematopoietic stem cell.     

骨髓干细胞移植促进ctnt^R141W转基因小鼠心肌组织再生

目的观察骨髓干细胞移植对ctnt^R141W转基因小鼠心脏组织结构的重建和病变心脏的泵血功能的影响。方法放射线9Gy照射ctnt^R141W转基因小鼠,将绿色荧光蛋白转基因小鼠的骨髓细胞尾静脉注射入ctnt^R141W转基因小鼠体内,替换ctnt^R141W转基因小鼠自身的骨髓细胞。流式细胞仪分析移植后的ctnt^R141W转基因小鼠绿色荧光骨髓干细胞所占的百分比。用免疫荧光双染方法探测移植后的ctnt^R141W转基因小鼠心肌组织中绿色荧光心肌细胞所占的比例,M型超声检测ctnt^R141W转基因小鼠心脏功能变化。结果相对于野生型对照小鼠ctnt^R141W转基因小鼠心肌组织中绿色荧光心肌细胞显著增加,左心室内径缩小,室壁变厚,收缩期末期和舒张末期左室容积缩小,心脏泵血功能增强。结论移植后的骨髓干细胞参与ctnt^R141W转基因小鼠心肌组织的损伤后重建,有助于改善病变心脏的泵血功能。研究提示扩张型心肌病心肌组织损伤重建增加,移植后的骨髓干细胞在受损心肌组织再生过程中起重要作用。     

Bone marrow (BM) transplantation promotes beta-cell regeneration after acute injury through BM cell mobilization

There is controversy regarding the roles of bone marrow (BM)-derived cells in pancreatic beta-cell regeneration. To examine these roles in vivo, mice were treated with streptozotocin (STZ), followed by bone marrow transplantation (BMT; lethal irradiation and subsequent BM cell infusion) from green fluorescence protein transgenic mice. BMT improved STZ-induced hyperglycemia, nearly normalizing glucose levels, with partially restored pancreatic islet number and size, whereas simple BM cell infusion without preirradiation had no effects. In post-BMT mice, most islets were located near pancreatic ducts and substantial numbers of bromodeoxyuridine-positive cells were detected in islets and ducts. Importantly, green fluorescence protein-positive, i.e. BM-derived, cells were detected around islets and were CD45 positive but not insulin positive. Then to examine whether BM-derived cell mobilization contributes to this process, we used Nos3(-/-) mice as a model of impaired BM-derived cell mobilization. In streptozotocin-treated Nos3(-/-) mice, the effects of BMT on blood glucose, islet number, bromodeoxyuridine-positive cells in islets, and CD45-positive cells around islets were much smaller than those in streptozotocin-treated Nos3(+/+) controls. A series of BMT experiments using Nos3(+/+) and Nos3(-/-) mice showed hyperglycemia-improving effects of BMT to correlate inversely with the severity of myelosuppression and delay of peripheral white blood cell recovery. Thus, mobilization of BM-derived cells is critical for BMT-induced beta-cell regeneration after injury. The present results suggest that homing of donor BM-derived cells in BM and subsequent mobilization into the injured periphery are required for BMT-induced regeneration of recipient pancreatic beta-cells.