Wnt信号通路在压力调控骨髓间充质干细胞膜片成软骨响应中的作用

目的:研究经典(Wnt/β-catenin,Wnt)信号通路在压力调控骨髓间充质干细胞(bone marrow-derived mesenchymal stem cells,BMSCs)膜片成软骨响应中的作用。方法:体外分离、培养兔BMSCs,经鉴定后用含有抗坏血酸的培养基构建BMSCs细胞膜片,并将其随机分2组;对照组在常规条件下培养4 d,实验组施以120 KPa静态压力,1 h/d、连续4 d。然后通过Western Blot检测经典Wnt信号通路相关蛋白的表达水平;Real-time PCR检测Wnt信号通路相关基因和成软骨基因的表达水平。结果:兔BMSCs传代后生长状态稳定,呈梭形;成骨成脂分化诱导实验结果阳性;Western Blot检测显示,实验组β-catenin和p-GSK3β蛋白表达水平均明显高于对照组(P<0.05);Real-time PCR检测显示,实验组经典Wnt信号通路相关基因β-catenin、p-GSK3βmRNA以及成软骨相关基因Col-Ⅱ、Sox-9、Aggrecan mRNA的表达水平均明显高于对照组(P<0.05)。结论:Wnt/β-catenin信号通路介导兔BMSCs膜片在一定的压力刺激下的成软骨响应过程。

骨髓间充质干细胞成骨性能的实验研究

目的研究骨髓间充质干细胞的生物学特性以及作为组织工程骨种子细胞的特点。方法分离培养兔骨髓间充质干细胞,与纳米晶羟基磷灰石胶原材料于体外联合培养,建立兔桡骨节段性缺损模型,分为空白组(n=8,不植入材料)、对照组(n=8,植入材料)、实验组(n=8,植入复合细胞的材料)。通过大体观察、组织学分析及X线摄片了解成骨情况。结果兔骨髓间充质干细胞在体外可以大量增殖,复合细胞的材料植入16周后,X线摄片可见桡骨缺损处连接良好。结论骨髓间充质干细胞具有很强的成骨作用,是一种较好的组织工程种子细胞。

神经营养因子3促进骨髓间充质干细胞向类神经元分化的信号通路

骨髓间充质干细胞在适当环境中，可被诱导分化为神经元，及神经胶质细胞，被认为是最好的种子细胞。神经营养因子3为一种多功能的神经营养因子，对神经系统的发育及维持其正常生理功能具有重要意义。文章旨在探讨神经营养因子3促进骨髓问充质干细胞向类神经细胞分化的作用及可能的信号传导通路。

ICR小鼠骨髓间充质干细胞分离及生物学特性的探讨

目的探讨分离、培养的ICR（Institute of Cancer Research，ICR）小鼠骨髓间充质干细胞（mouse bone marrow mesenchymal stem cells，mBM—MSCs）的细胞生物学特性。方法取6～8周龄ICR小鼠，利用全骨髓反复贴壁和有限稀释培养法分离纯化mBM—MSCs，观察形态特点，测定生长曲线和活力，利用流式细胞仪分析细胞的周期和鉴定表面抗原，诱导其向成骨、软骨及脂肪细胞分化，采用染色法鉴定。结果新分离的mBM—MSCs多呈小圆形，形态规整。培养传代后，细胞多变为梭形，大小较均匀，形态较一致。随着传代的次数增加，细胞的生长曲线、活力及周期呈现快速发育期、平台期和缓慢期；流式结果细胞CD44、CD73、SCA-1呈阳性反应，部分细胞CD90、CD105、STRO-1呈阳性反应，CD11b和CD45呈阴性反应；诱导分化为成骨细胞后其碱性磷酸酶、茜素红和YonKossa银染色均呈阳性反应，分化成脂肪细胞后油红O染色呈阳性反应，分化成软骨细胞后阿尔新蓝染色呈阳性反应。结论ICR小鼠骨髓中分离培养出的MSCs，生物学特点鲜明，适于做进一步研究。

低氧预处理在骨髓间充质干细胞缺氧再灌注损伤中的保护作用

目的:探讨低氧预处理在骨髓间充质干细胞(BMSCs)缺氧再灌注损伤中的保护作用。方法 :将体外正常培养的原代BMSCs随机分为4组,包括正常组(normal group)、低氧预处理组(hypoxia preconditioning,HP)、缺氧再灌注组(hypoxia-reoxygenation,HR)和低氧预处理-缺氧再灌注组(HP-HR)。分别对HP组和HP-HR组的BMSCs在原代、P1代和P2代连续3代进行低氧(1%O2)预处理30min;对HR组和HP-HR组的P3代BMSCs进行完全缺血缺氧3小时再复氧1天,然后用MTT法同时检测4组P3代BMSCs的细胞活力,并用Hoechst33342及Bax染色观察细胞的凋亡。结果:正常培养组与HP组P3代细胞的活力没有显著性差异,而HR组和HP-HR组的细胞活力均明显下降。但HP-HR组的细胞活力较HR组显著提高,差异有统计学意义(P<0.05),而且Hoechst33342及Bax染色显示细胞凋亡在HP-HR组较HR组减少。结论:低氧预处理能够减少细胞凋亡,保护骨髓间充质干细胞防止缺氧再灌注损伤。

骨髓间充质干细胞移植对急性肺水肿大鼠血清IL-6与SP-A的作用研究

目的:通过肺组织形态学及血清细胞因子(IL-6、SP-A)水平观察骨髓间充质干细胞对大鼠急性肺水肿的防治作用。方法:80只SD大鼠随机分为肺水肿组、干细胞治疗组、干细胞预防组、空白对照组、干细胞对照组(各16只)。腹腔注射氯化铵建立急性肺水肿组织模型,预防组及治疗组于模型建立前后移植MSCs1×105/只,移植后30min、2h、1d、7d光镜及电镜扫描观察肺组织病理,测定血IL-6、SP-A水平。结果:移植后2h时肺水肿组病变明显,治疗组肺水肿病变减轻。治疗组2h时IL-6明显低于肺水肿组(P<0.01),在30min SP-A水平明显高于肺水肿组(P<0.01),而预防组与肺水肿组无差异(P>0.05)。结论:MSCs移植治疗减轻急性肺水肿,预防性移植不减轻肺水肿。

大鼠骨髓间充质干细胞促进肝星状细胞凋亡的机制研究

目的探讨大鼠骨髓间充质干细胞（BMSC）与肝星状细胞（HSC）共培养体系中BMSC旁分泌肝细胞生长因子（HGF）对HSC凋亡的影响及其机制。方法用半透膜建立上下双层细胞共培养体系，各组培养24、48、72h，倒置相差显微镜观察细胞形态学变化，免疫细胞化学法观察α-肌动蛋白（仅-SMA）表达情况；四甲基偶氮唑盐法检测Y-27632及PHA665752的最佳干预浓度l流式细胞仪检测HSC凋亡率lWesternNot、实时荧光定量PCR检测肝星状细胞RhoAmRNA及蛋白表达情况；酶联免疫吸附法检测HGF及肝细胞生长因子激活因子（HGFA）浓度。计量资料采用单因素方差分析，P〈0．05为差异有统计学意义。结果随着时间的延长，HSC凋亡率逐渐增高，实验b组凋亡率最低，实验c组凋亡率最高，均以72h最为显著，各组在各时段凋亡率差异具有统计学意义（P〈0．05）；实验C组RhoA蛋白及mRNA表达量较其他各组明显下降，差异有统计学意义（P〈0．05）；各组RhoA蛋白及mRNA表达量随时间的延长而逐渐增加；实验各组HGF浓度随时间延长逐渐降低，实验b、c组较对照组增高，差异有统计学意义（P〈0．05）；实验各组HGFA浓度随时间延长逐渐增高，实验b组升高最为明显，差异有统计学意义（P〈0．01）。结论BMSC通过激活HGF并下调Rho通路促进肝星状细胞凋亡。

成软骨诱导的骨髓间充质干细胞膜片修复肋软骨供区缺损的实验研究

目的采用兔胸廓损伤动物模型，观察成软骨诱导的骨髓间充质干细胞膜片对肋软骨供区再生修复的影响。方法将16只家兔随机分为4组，每组4只，分别为健康对照组，实验1、2、3组。健康对照组家兔无任何处理，对实验组的每组双侧第4—6肋软骨均采用不同的2种方法处理，同侧3根肋软骨采用同一种方法处理，3种方法在每组中两两配对。3种方法分别为：①直接缝合软骨膜；②骨髓间充质干细胞膜片折叠数层成圆筒状填塞人肋软骨缺损处缝合；③成软骨诱导的骨髓间充质干细胞膜片同法折叠数层成圆筒状填塞入肋软骨缺损处，缝合封闭缺损。3种方法在各实验组兔两侧肋软骨中两两配对，健康对照组不做处理。术后16周，处死家兔取材进行大体观察，常规HE染色，并行生物力学检测，测定所有肋软骨的抗压强度及弯曲强度。结果各实验组家兔的胸廓整体形态均较良好，各组及各处理方法间无明显差别。生物力学检测显示，3种处理方法之间均存在差异（P〈0．01），方法3处理的修复组织的抗压、弯曲强度与健康对照组比较，差异无统计学意义（P〉0．05）；方法1、2处理的修复组织的抗压、弯曲强度明显低于健康对照组（P〈0．01）；方法2处理的修复组织的抗压、弯曲强度优于方法1。组织切片HE染色病理观察，可见方法1、2处理的修复组织主要为纤维组织，方法3处理的修复组织内，可见新生的软骨细胞和大量的软骨细胞外基质。结论成软骨诱导的骨髓间充质干细胞膜片可以促进肋软骨供区软骨细胞的再生，修复肋软骨供区缺损，维持胸廓的正常形态和稳定性，从而降低术后胸廓畸形的发生率。

Hedgehog信号通路在人角膜缘微环境来源的基质干细胞中表达情况的研究(英文)

目的:探讨Hedgehog信号通路在人角膜缘微环境来源的基质干细胞(LNC)中的表达情况。方法:对贴壁生长的人角膜缘来源的基质干细胞(LNC)进行分离培养及传代,对骨髓间充质干细胞系(BMMSC)进行培养传代。通过将BMMSC作为阳性对照,采用Western blot技术,免疫荧光技术,real-time PCR技术从蛋白水平及基因水平验证Hedgehog信号通路成员SHH,patched,SMO,Gli-1在LNC中的表达情况。最后采用Cell Count Kit-8检测不同浓度Gli抑制剂GANT61(空白,1,5,10,15,20,25,30μmol/L)处理LNC和BMMSC48h后的增殖抑制效应反向验证Hedgehog信号通路在LNC中的存在。结果:Western blot技术,免疫荧光技术,real-time PCR技术均证明LNC细胞表达Hedgehog信号通路中的Gli-1,patched,SMO,且Gli蛋白抑制剂GANT61可以显著抑制LNC细胞增殖(P<0.05)。结论:Hedgehog信号通路在LNC细胞的增殖过程中发挥重要作用。

Rat bone marrow mesenchymal stem cells differentiate into hepatocytes in vitro

AIM: To investigate the mechanism and regulation of differentiation from bone marrow mesenchymal stem cells (MSCs) into hepatocytes and to find a new source of celltypes for therapies of hepatic diseases. METHODS: MSCs were isolated by combining gradient density centrifugation with plastic adherence. The cells were cultured in osteogenic or adipogenic differentiation medium and determined by histochemical staining. MSCs were plated in plastic culture flasks that were not coated with components of extracellular matrix (ECM). When MSCs reached 70% confluence, they were cultured in low glucose Dulbecco's modified Eagle's medium supplemented with 10 mL/L fetal bovine serum, 20 ng/mL hepatocyte growth factor (HGF) and 10 ng/mL fibroblast growth factor-4 (FGF-4). The medium was changed every 3 d and stored for albumin, alpha-fetoprotein (AFP) and urea assay. Glycogen store of hepatocytes was determined by periodic acid-Schiff staining.RESULTS: By combining gradient density centrifugation with plastic adherence, we isolated a homogeneous population of cells from rat bone marrow and differentiated them into osteocytes and adipocytes. When MSCs were cultured withFGF-4 and HGF, approximately 56.6% of cells became smallround and epithelioid on d 24 by morphology. Compared with the control, levels of AFP increased significantly from d 12 to 15.5±1.4 μg/L (t = 2.31, P＜0.05) in MSCs cultured with FGF-4and HGF, and were higher (46.2±1.5 μg/L)ond 21 (t = 41.926, P＜0.01), then decreased to 24.8±2.2 μg/L on d 24 (t = 10.345, P＜0.01). Albumin increased significantly on d 21 (t= 3.325, P＜0.01) to 1.4±0.2 μg/mL,and to 2.1±0.7 μg/mL on d 24 (t= 3.646, P＜0.01). Urea(2.3±0.4 mmol/L) was first detected on d 21 (t = 6.739, P＜0.01), and continued to increase to 2.6±0.9 mmol/Lon d 24 (t= 4.753, P＜0.01). Glycogen storage was first seen on d 21.CONCLUSION: The method combining gradient density centrifugation with plastic adherence can isolate MSCs. Rat MSCs may be differentiated into hepatocytes by FGF-4 and HGF. Cytokines may play a more important role in differentiation from rat MSCs into hepatocytes.

Intravenous injection of mesenchymal stem cells is effective in treating liver fibrosis

AIM: To compare the influence of different transplant sites in bone marrow mesenchymal stem cell (MSC)-based therapy for liver fibrosis. METHODS: MSCs isolated from Sprague Dawley (SD) rats were induced into hepatocyte-like cells. Liver fibrosis in SD rats was induced with carbon tetrachloride. Following hepatocyte induction in vitro, 4',6-diamidino- 2-phenylindole (DAPI)-labeled MSCs were transplanted by intravenous, intrahepatic, and intraperitoneal injection. Histopathological staining, immunohistochemistry, and biochemical analysis were used to compare the morphological and functional liver regeneration among different MSC injection modalities. The expression differences of interleukins, growth factor, extracellular matrix, matrix metalloproteinases, and tissue inhibitor of metalloproteinase were examined by real-time reverse transcription-polymerase chain reaction (RT-PCR) andenzyme linked immunosorbent assay (ELISA). RESULTS: Four days after exposure to hepatocyte differentiation medium, MSCs that did not express hepatocyte markers could express α-fetoprotein, albumin, and cytokeratin 18. The results of histopathological staining, immunohistochemistry, and biochemical analysis indicated that intravenous injection is more effective at rescuing liver failure than other injection modalities. DAPI-labeled cells were found around liver lobules in all three injection site groups, but the intravenous group had the highest number of cells. PCR and ELISA analysis indicated that interleukin-10 (IL-10) was highest in the intravenous group, whereas il1β, il6, tnfα and tgfβ, which can be regulated by IL10 and are promoters of liver fibrosis, were significantly lower than in the other groups. CONCLUSION: MSC administration is able to protect against liver fibrosis. Intravenous injection is the most favorable treatment modality through promotion of IL10 expression.

Bone marrow mesenchymal stem cell transplantation combined with perindopril treatment attenuates infarction remodelling in a rat model of acute myocardial infarction

Objective: This study was performed to evaluate whether implantation of mesenchymal stem cell (MSC) would reduce left ventricular remodelling from the molecular mechanisms compared with angiotensin-converting enzyme inhibitors (ACEIs) perindopril into ischemic myocardium after acute myocardial infarction. Methods: Forty rats were divided into four groups: control, MSC, ACEI, MSC+ACEI groups. Bone marrow stem cell derived rat was injected immediately into a zone made ischemic by coronary artery ligation in MSC group and MSC+ACEI group. Phosphate-buffered saline (PBS) was injected into control group. Perindopril was administered p.o. to ACEI group and MSC+ACEI group. Six weeks after implantation, the rats were killed and heart sample was collected. Fibrillar collagen was observed by meliorative Masson’s trichome stain. Western Blotting was employed to evaluate the protein expression of matrix metalloproteinase (MMP)-2, matrix metalloproteinase (MMP)-9 in infarction zone. The transcriptional level of MMP2, MMP9 and tissue inhibitor of matrix metalloproteinase (TIMP)-1 in infarction area was detected by reverse transcriptase PCR (RT-PCR) analysis. Results: The fibrillar collagen area, the protein expression of MMP2, MMP9 and the transcriptional level of MMP2, MMP9 mRNA in infarction zone reduced in MSC group, ACEI group, and MSC+ACEI group. No significant difference was detected in the expression of TIMP1 mRNA among the 4 groups. Conclusion: Both MSC and ACEI could reduce infarction remodelling by altering collagen metabolism.

Comparison of human amniotic fluid-derived and umbilical cord Wharton＇s Jelly-derived mesenchymal stromal cells： Characterization and myocardial differentiation capacity

Objective To compare the characterization and myocardial differentiation capacity of arnniotic fluid-derived mesenchymal stromal cells （AF MSCs） and umbilical cord Wharton＇s Jelly-derived mesenchymal stromal cells （WJ MSCs）. Methods The human AF MSCs were cultured from amniotic fluid samples obtained by amniocentesis. The umbilical cord WJ MSCs were obtained from Wharton＇s Jelly of umbilical cords of infants delivered full-term by normal labor. The morphology, growth curves, and analyses by flow cytometry of cell surface markers were compared between the two types of cells. Myocardial genes （GATA-4, c-TnT, a-actin, and Cx43） were detected by real-time PCR and the corresponding protein expressions were detected by Western blot analysis after myocardial induced in AF MSCs and WJ MSCs. Results Our findings revealed AF MSCs and WJ MSCs shared similar morphological characteristics of the fibroblastoid shape. The AF MSCs were easily obtained than the WJ MSCs and had a shorter time to reach adherence of 2.7 ± 1.6 days to WJ MSCs of 6.5 ± 1.8 days. The growth curves by MTT cytotoxic assay showed the AF MSCs had a similar proliferative capacity at passage 5 and passage 10. However, the proliferative capacities ofWJ MSCs were decreased at 5 passage relative to 10 passage. Both AF stem cells and WJ stem cells had the characteristics of mesenchymal stromal cells with some characteristics of embryonic stem cells. They express CD29 and CD105, but not CD34. They were positive for Class I major histocompatibility （MHC I） antigens （HLA-ABC）, and were negative, or mildly positive, for MHC Class II （HLA-DR） antigen. Oct-4 was positive in all the two cells types. Both AF MSCs and WJ MSCs could differentiate along myocardium. The differentiation capacities were detected by the expression of GATA-4, c-TnT, a-actin, Cx43 after myocardial induction. Conclusions Both AF MSCs and WJ MSCs have the potential clinical application for myogenesis in cardiac regenerative therapy.

Rubidium-modified bioactive glass-ceramics with hydroxyapatite crystals for bone regeneration

In order to study the influence of rubidium(Rb)addition on the phase composition,microstructure,mechanical properties and cell response of bioactive glass-ceramics,CaO−SiO2−Na2O−B2O3−MgO−ZnO−P2O5 glass system was designed with and without addition of Rb.The results show that hydroxyapatite(HA)and Mg−whitelockite(Ca18Mg2H2(PO4)14)crystalline phases are formed in the glass matrix without Rb.After the addition of Rb,only HA phase is detected.The grain size of the crystals in the glass-ceramics is larger with the addition of Rb than that of samples without Rb.Rb addition can improve the bending strength of glass-ceramics.The cultivation of human bone marrow mesenchymal stem cells(hBMSCs)on Rb-containing glass-ceramics demonstrates enhanced cell adhesion,proliferation and ALP activity.In conclusion,Rb-modified glass-ceramics exhibit good mechanical property,excellent bioactivity and biocompatibility,which have potential for bone regeneration application.

Mesenchymal stromal cells' role in tumor microenvironment:involvement of signaling pathways

Mesenchymal stromal cells(MSCs) are adult multipotent stem cells residing as pericytes in various tissues and organs where they can differentiate into specialized cells to replace dying cells and damaged tissues. These cells are commonly found at injury sites and in tumors that are known to behave like "wounds that do not heal." In this article, we discuss the mechanisms of MSCs in migrating, homing, and repairing injured tissues. We also review a number of reports showing that tumor microenvironment triggers plasticity mechanisms in MSCs to induce malignant neoplastic tissue formation, maintenance, and chemoresistance, as well as tumor growth. The antitumor properties and therapeutic potential of MSCs are also discussed.

Effect of CXCR3/HO-1 genes modified bone marrow mesenchymal stem cells on small bowel transplant rejection

AIM To investigate whether bone marrow mesenchymal stem cells (BMMSCs) modified with the HO-1 and CXCR3 genes can augment the inhibitory effect of BMMSCs on small bowel transplant rejection. METHODS Lewis rat BMMSCs were cultured in vitro. Third-passage BMMSCs were transduced with the CXCR3 / HO-1 genes or the HO-1 gene alone. The rats were divided into six groups and rats in the experimental group were pretreated with BMMSCs 7 d prior to small bowel transplant. Six time points (instant, 1 d, 3 d, 7 d, 10 d, and 14 d) (n = 6) were chosen for each group. Hematoxylin-eosin staining was used to observe pathologic rejection, while immunohistochemistry and Western blot were used to detect protein expression. Flow cytometry was used to detect T lymphocytes and enzyme linked immunosorbent assay was used to detect cytokines. RESULTS The median survival time of BMMSCs from the CXCR3/HO-1 modified group (53 d) was significantly longer than that of the HO-1 modified BMMSCs group (39 d), the BMMSCs group (26 d), and the NS group (control group) (16 d) (P < 0.05). Compared with BMMSCs from the HO-1 modified BMMSCs, BMMSCs, and NS groups, rejection of the small bowel in the CXCR3 / HO-1 modified group was significantly reduced, while the weight of transplant recipients was also significantly decreased (P < 0.05). Furthermore, IL-2, IL-6, IL-17, IFN-gamma, and TNF-alpha levels were significantly decreased and the levels of IL-10 and TGF-beta were significantly increased (P < 0.05). CONCLUSION BMMSCs modified with the CXCR3 and HO-1 genes can abrogate the rejection of transplanted small bowel more effectively and significantly increase the survival time of rats that receive a small bowel transplant.

Role of bone marrow-derived mesenchymal stem cells in a rat model of severe acute pancreatitis

AIM:To investigate the role and potential mechanisms of bone marrow mesenchymal stem cells(MSCs) in severe acute peritonitis(SAP).METHODS:Pancreatic acinar cells from Sprague Dawley rats were randomly divided into three groups:nonsodium deoxycholate(SDOC) group(non-SODC group),SDOC group,and a MSCs intervention group(i.e.,a co-culture system of MSCs and pancreatic acinar cells + SDOC).The cell survival rate,the concentration of malonaldehyde(MDA),the density of superoxide dismutase(SOD),serum amylase(AMS) secretion rate and lactate dehydrogenase(LDH) leakage rate were detected at various time points.In a separate study,Sprague Dawley rats were randomly divided into either an SAP group or an SAP + MSCs group.Serum AMS,MDA and SOD,interleukin(IL)-6,IL-10,and tumor necrosis factor(TNF)-α levels,intestinal mucosa injury scores and proliferating cells of small intestinal mucosa were measured at various time points after injecting either MSCs or saline into rats.In both studies,the protective effect of MSCs was evaluated.RESULTS:In vitro,The cell survival rate of pancreatic acinar cells and the density of SOD were significantly reduced,and the concentration of MDA,AMS secretion rate and LDH leakage rate were significantly increased in the SDOC group compared with the MSCs intervention group and the Non-SDOC group at each time point.In vivo,Serum AMS,IL-6,TNF-α and MAD level in the SAP + MSCs group were lower than the SAP group;however serum IL-10 level was higher than the SAP group.Serum SOD level was higher than the SAP group at each time point,whereas a significant betweengroup difference in SOD level was only noted after 24 h.Intestinal mucosa injury scores was significantly reduced and the proliferating cells of small intestinal mucosa became obvious after injecting MSCs.CONCLUSION:MSCs can effectively relieve injury to pancreatic acinar cells and small intestinal epithelium,promote the proliferation of enteric epithelium and repair of the mucosa,attenuate systemic inflammation in rats with SAP.

Short- and Long-term Therapeutic Efficacies of Intravenous Transplantation of Bone Marrow Stem Cells on Cardiac Function in Rats with Acute Myocardial Infarction:A Meta-analysis of Randomized Controlled Trials

Objective To investigate the short- and long-term therapeutic efficacies of intravenous transplantation of bone marrow stem cells(MSCs) in rats with experimental myocardial infarction by metaanalysis.Methods Randomized controlled trials were systematically searched from Pub Med,Science Citation Index(SCI),Chinese journal full-text database(CJFD) up to December 2014.While the experimental groups(MSCs groups) were injected MSCs intravenously,the control groups were injected Delubecco's minimum essential medium(DMEM) or phosphate buffered saline(PBS).Subgroup analysis for each outcome measure was performed for the observing time point after the transplantation of MSCs.Weighted mean differences(WMD) and 95% confidence intervals(CI) were calculated for outcome parameters including ejection fraction(EF) and fractional shortening(FS),which were measured by echocardiogram after intravenous injection and analyzed by Rev Man 5.2 and STATA 12.0.Results Data from 9 studies(190 rats) were included in the meta-analysis.As compared to the control groups,the cardiac function of the experimental groups were not improved at day 7(EF:WMD=0.08,95%CI-1.32 to 1.16,P>0.01; FS:WMD=-0.12,95%CI-0.90 to 0.65,P>0.01) until at day 14 after MSCs' transplantation(EF:WMD=10.79,95%CI 9.16 to 12.42,P<0.01; FS:WMD=11.34,95%CI 10.44 to 12.23,P<0.01),and it lasted 4 weeks or more after transplantation of MSCs(EF:WMD=13.94,95%CI 12.24 to 15.64,P<0.01; FS:WMD=9.64,95%CI 7.98 to 11.31,P<0.01).Conclusion The therapeutic efficacies of MSCs in rats with myocardid infarction become increasing apparent as time advances since 2 weeks after injection.

Pretreatment with Lithospermic Acid Attenuates Oxidative Stress-induced Apoptosis in Bone Marrow-derived Mesenchymal Stem Cells via Anti-oxidation and Activation of PI3K/Akt Pathway

Objective Despite the potential therapeutic approaches of bone marrow-derived mesenchymal stem cells(BMSCs)in orthopaedic,their applications are hampered by harsh oxidative stress conditions after transplantation.In this study,the antiapoptotic and anti-oxidative properties of lithospermic acid(LSA)on BMSCs exposed to hydrogen peroxide(H2O2)were investigated.Methods In the present study,we used H2O2 to induce oxidative injury on BMSCs.Reactive oxygen species(ROS)staining and superoxide dismutase(SOD)assay were performed.The expression levels of phosphorylated(p)-Akt,Bcl-2-associated X protein(Bax)and B-cell lymphoma 2(Bcl-2)were measured by Western blotting.Results LSA can significantly reduce H2O2-induced chromatin condensation and intracellular ROS levels,enhance the activity of SOD.Moreover,it can alleviate H2O2-induced apoptosis by upregulating Bcl-2 and p-Akt,down-regulating Bax,which was blocked by the PI3K inhibitor,LY294002.Conclusions Our results demonstrated that pretreatment with LSA could attenuate oxidative stress-induced apoptosis in BMSCs,which may be related with anti-oxidant properties and partly via modulating PI3K/Akt pathway,suggesting that pharmacologically manipulating BMSCs with LSA could be a promising drug to increase cell survival for BMSCs transplantation in musculoskeletal disorders of orthopaedic.

Transplanted bone marrow stromal cells are not cellular origin of hepatocellular carcinomas in a mouse model of carcinogenesis

AIM:To investigate the malignant potential of hepatic stem cells derived from the bone marrow stromal cells (BMSCs) in a mouse model of chemical hepatocarcino- genesis. METHODS:BMSCs from male BALB/c mice were harvested and cultured, then transplanted into female syngenic BALB/ c mice via portal vein. Hepato-carcinogenesis was induced by 6 mo of treatment with diethylnitrosamine (DEN). Six months later, the liver was removed from each treated mouse and evaluated by immunohistochemistry and fluorescence in situ hybridization (FISH). RESULTS:Twenty-six percent of recipient mice survived and developed multiple hepatocellular carcinomas (HCCs). Immunohistochemically, HCC expressed placental form of glutathione-S-transferase (GST-P) and α-fetoprotein, but did not express cytokeratin 19. Y chromosome positive hepatocytes were detected by fluorescent in situ hybridization (FISH) in the liver of mice treated with DEN after BMSCs transplantation while no such hepatocytes were identified in the liver of mice not treated with DEN. No HCC was positive for the Y chromosome by FISH. CONCLUSION:Hepatic stem cells derived from the bone marrow stromal cells have a low malignant potential in our mouse model of chemical hepatocarcingenesis.