Survival of bone marrow-derived mesenchymal stem cells in a xenotransplantation model.

Mesenchymal stem cells (MSCs) are immunoprivileged and the allogeneic MSCs implantation has been used to facilitate tissue repairs such as bone and cartilage defect. The present study aimed to investigate the feasibility of xenogeneic MSCs implantation. Green fluorescent protein (GFP) transgenic rat bone marrow-derived MSCs were loaded into HA/TCP Skelite blocks and implanted intramuscularly into the quadriceps of the MF1 and SCID mice. After 11 weeks, the implants were harvested and processed for further examinations. The peripheral blood mononuclear cells of each animal were also collected to measure the in vitro immune responses using mixed lymphocyte culture and cytotoxic assay. In the MF1 mice, some surviving MSCs were found in the explants after 11 weeks of implantation, but there was no sign of new bone formation as neither osteocalcin mRNA nor osteoid tissues were detected in the explants; the lymphocyte proliferation and cytotoxicity against donor MSCs were significantly increased in the animals with the xenogeneic MSCs implantation compared with the control littermates without transplantation. In the control SCID mice, osteoid tissues derived from the implanted MSCs were found in the explants; no difference of lymphocyte proliferation and cytotoxicity against the donor MSCs was detected between the SCID mice with or without MSCs implantation. The data suggested that rat MSCs survived the 11 weeks of xenotransplantation in the MF1 mice, but the increased host immune sensitization led to the impaired in vivo osteogenesis potential of MSCs.     

人骨形态发生蛋白-2基因转染兔骨髓基质干细胞及其表达

目的探讨含有人骨形态发生蛋白-2(hBMP-2)cDNA的真核表达载体在兔骨髓基质干细胞(MSCs)中的转录及表达情况,为进一步进行多基因转染MSCs复合纳米仿生骨治疗骨缺损实验提供材料。方法用电穿孔方法将真核表达载体pIRES2-EGFP-hBMP2转染至兔MSCs中,荧光显微镜及流式细胞学检查观察转染效果、检测转染效率,定量RT-PCR方法观察hBMP-2cDNA在兔MSCs中的转录情况,免疫组织化学及westernblot方法检测hBMP-2蛋白表达情况,ALP活性定量测定检测hBMP-2蛋白功能。结果电穿孔方法将重组质粒转染至兔MSCs中,荧光显微镜下观察到绿色荧光蛋白表达,流式细胞仪检测转染效率为(42.7±2.1)%,转染24h后定量RT-PCR方法检测到hBMP-2cDNA在兔MSCs中的转录片断,免疫组织化学观察到hBMP-2蛋白呈强阳性表达,westernblot方法可见18KDhBMP-2蛋白条带,转染组细胞ALP活性明显提高(P>0.05)。结论pIRES2-EGFP-hBMP2通过电穿孔方法导入兔MSCs,并在其中有效表达,发挥生物学作用。     

Ad-GFP修饰MSCs静脉移植在严重烫伤延迟复苏大鼠体内的定向迁移

目的:观察携带目的基因的大鼠骨髓间充质干细胞(mesenchymal stem cells ,MSCs) 静脉移植在严重烫伤延迟复苏损伤体内的分布.方法:分离培养MSCs,用Ad-GFP转染MSCs,25只Wistar大鼠随机分为延迟复苏组(A组,10只)、即时复苏组(B组,10只)、假伤组(C组,5只).A、B两组大鼠背部造成Ⅲ度30%烫伤,制备A组为延迟复苏模型,B组为即时复苏模型,同时制备C组为假伤模型,经股静脉移植转染Ad-GFP 48 h后的MSCs.24 h,7 d后取小肠、肝脏、肾脏、烫伤皮肤创缘等组织,快速冰冻切片,荧光显微镜下观察在体内的分布.结果:MSCs 体外分离培养扩增5代,细胞数可达(1～2)×1011个,具有多态性和贴壁生长特性,MOI=100时,Ad-GFP转染MSCs效率可达86.4%.经股静脉移植24 h,在延迟复苏组烫伤皮肤组织创缘,小肠黏膜广泛可见绿色荧光,而在肝、肺等器官少见,即时复苏组荧光以烫伤皮肤创缘分布为主,小肠黏膜较少,假伤组中绿色荧光分布以肝脏为主.延迟复苏组小肠荧光强度明显强于即时复苏组和假伤组(P《0.05),而延迟和即时复苏组皮肤创缘荧光强度又强于假伤组(P《0.05).结论:导入目的基因可能不会改变MSCs归巢特性,并将为后续启动基因治疗烧伤延迟复苏后的损伤研究提供参考.     

Development of HLA-matched vascular grafts utilizing decellularized human umbilical artery

Worldwide, there is a great need of small diameter vascular grafts that can be used in human disorders such as cardiovascular and peripheral vascular disease. Until now, severe adverse reactions are caused from the use of synthetic or animal derived grafts, while the use of autologous vessels is restricted only in a small number of patients. The limited availability of the vessels might be resolved by the use of HLA-matched vascular grafts utilizing the decellularized human umbilical arteries. In this study, human umbilical arteries were decellularized and then repopulated with Mesenchymal Stem Cells. The HLA-genotype of the repopulated grafts, analyzed by Next Generation Sequencing technology, indicated their successful production. The HLA-matched vascular grafts could be generated efficiently and might be used in personalized medicine.     

骨髓间质干细胞对血管性痴呆大鼠BDNF和NGF的影响

目的:观察静脉注射骨髓间质干细胞(marrowstromalcell,MSC)对血管性痴呆(vasculardementia,VD)大鼠脑组织脑源性神经营养因子(BDNF)和神经生长因子(NGF)表达的影响。方法:体外分离培养、扩增成年大鼠MSC。利用结扎双侧颈总动脉方法制备慢性前脑缺血动物模型,利用穿梭箱、水迷宫试验、ELISA方法检测注射MSC后30,60dVD大鼠认知功能以及脑组织BDNF和NGF含量变化。结果:与正常对照组相比,VD大鼠主动回避反应、游泳时间、错误次数和盲端时间,在造模后30和60d差异有显著性意义(P<0.01)。静脉注射MSC后30和60d,VD大鼠认知功能显著改善。造模后30,60d大鼠脑BDNF含量犤(96±27),(108±26)ng/g犦,NGF含量犤(73±22),(89±24)ng/g犦较对照组显著增高犤(51±13)ng/g,(36±11)ng/g犦,P<0.01;注射MSC后30,60d大鼠脑BDNF含量犤(180±46),(185±5)ng/g犦,NGF含量犤(115±29),(108±34)ng/g犦较模型组显著升高。结论:静脉注射MSC可显著改善VD大鼠认知功能,增加VD大鼠脑组织BDNF和NGF含量。     

Mesenchymal stem cells are enriched in head neck squamous cell carcinoma,correlates with tumour size and inhibit T-cell proliferation

Background:

Cancer is a multifactorial disease not only restricted to transformed epithelium, but also involving cells of the immune system and cells of mesenchymal origin, particularly mesenchymal stem cells (MSCs). Mesenchymal stem cells contribute to blood- and lymph- neoangiogenesis, generate myofibroblasts, with pro-invasive activity and may suppress anti-tumour immunity.

Methods:

In this paper, we evaluated the presence and features of MSCs isolated from human head neck squamous cell carcinoma (HNSCC).

Results:

Fresh specimens of HNSCC showed higher proportions of CD90+ cells compared with normal tissue; these cells co-expressed CD29, CD105, and CD73, but not CD31, CD45, CD133, and human epithelial antigen similarly to bone marrow-derived MSCs (BM-MSCs). Adherent stromal cells isolated from tumour shared also differentiation potential with BM-MSCs, thus we named them as tumour-MSCs. Interestingly, tumour-MSCs showed a clear immunosuppressive activity on in vitro stimulated T lymphocytes, mainly mediated by indoelamine 2,3 dioxygenase activity, like BM-MSCs. To evaluate their possible role in tumour growth in vivo, we correlated tumour-MSC proportions with neoplasm size. Tumour-MSCs frequency directly correlated with tumour volume and inversely with the frequency of tumour-infiltrating leukocytes.

Conclusions:

These data support the concept that tumour-MSCs may favour tumour growth not only through their effect on stromal development, but also by inhibiting the anti-tumour immune response.     

Immunoregulatory role of exosomes derived from differentiating mesenchymal stromal cells on inflammation and osteogenesis

Bone marrow‐derived mesenchymal stem/stromal cells (BMSCs) can differentiate into bone‐forming osteoblasts, playing a crucial role in bone regeneration. Exosomes are naturally cell‐secreted nanovesicles and are lately regraded as an emerging mediator of cellular communication in physiological and pathological conditions. The present study aimed at investigating the complex cellular communications, especially those among the differentiating BMSCs, immune cells (e.g., macrophages), and newly recruited BMSCs via exosome‐mediated pathways. Exosomes were first isolated from osteogenically differentiating BMSCs at various stages (Day 0, Day 3, Day 7, and Day 14, respectively). The cellular uptake of isolated exosomes was examined in macrophages and human BMSCs (hBMSCs). The exosomes collected at various osteogenic differentiation stages (0d‐exo, 3d‐exo, 7d‐exo, and 14d‐exo) had no effect on the viability of hBMSCs. The uptake of exosomes (0d‐exo, 3d‐exo, and 7d‐exo) significantly decreased proinflammatory‐gene expression and the level of an M1 phenotypic marker. Our results then revealed that 3d‐exo, 7d‐exo, and 14d‐exo led to a remarkable increase in mesenchymal stem/stromal cell migration. In addition, 0d‐exo significantly promoted the expression of early osteogenic markers, such as alkaline phosphatase and bone morphogenetic protein 2, indicating a pro‐osteogenic role of hBMSC‐derived exosomes. Collectively, these results suggest that exosomes derived from differentiating mesenchymal stem/stromal cells play a unique osteoimmunomodulatory role in the regulation of bone dynamics.     

生物蛋白胶作为骨髓间充质干细胞移植载体的体外相容性研究

[目的]构建骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)-生物蛋白胶复合体评价其生物相容性,探讨其作为种子细胞载体的可行性。[方法]本实验分为两组,实验组5×107骨髓间充质干细胞(BMSCs)与生物蛋白胶相混制备MSC-生物蛋白胶复合体,空白组骨髓间充质干细胞(BMSCs)。通过Dead/live染色观察两组的细胞形态及21 d内细胞的存活情况,同时分别在1、3、7、14 d各取上清进行Elisa检测并计算其分泌释放NGF和BDNF的浓度。[结果]实验组培养3 d后光镜下观察呈多个突起,细胞形态良好,空白组呈菱形和多角形;Dead/live染色结果提示体外培养1 d,两组细胞的存活率都在90%,比较无差异,无统计学意义(P﹥0.05),7、14、21 d两组细胞的存活率有差异,具统计学意义(P﹤0.05),存活率在60%以上;Elisa检测结果显示两组中NGF在1 d时有差异,具统计学意义(P﹤0.05),3、7、14 d时NGF和BDNF的含量比较无统计学意义(P﹥0.05),结果显示生物蛋白胶对MSC分泌的细胞因子NGF和BDNF的释放没有明显影响。[结论]生物蛋白胶是一种理想的可用于临床的细胞载体,具有良好的生物相容性,BMSCs-生物蛋白胶复合体能持续稳定的释放神经生长因子BDNF和NGF。     

兔MSCs-PGA复合物在RCCS中的成骨潜能

目的：探讨联合应用兔骨髓基质干细胞（MSCs）、聚乙醇酸（PGA）支架材料和成骨诱导因子在旋转式细胞培养系统（RCCS）中构建组织工程化骨的可行性。方法：利用密度梯度离心法分离培养兔骨髓基质干细胞，采用动力接种方法形成骨髓基质干细胞-PGA支架复合物，以成骨条件培养液为生长介质，在RCCS中进行培养。用趋骨性荧光素四环素标记、茜素红染色以及扫描电镜、透射电镜观察，研究细胞-PGA支架在RCCS中的成骨潜能。结果：组织化学研究显示，兔骨髓基质干细胞-PGA支架结构中RCCS中培养第7d时，茜素红钙质染色呈弱阳性反应，至第21d及28d时，茜素红钙质染色呈强阳性反应。荧光显微锏上，培养组织趋骨性荧光素四环素标记呈现金黄色荧光，荧光亮度与分泌物堆积程度成正相关，与钙质染色阳性反应结果一致。超微结构观察，见骨髓基质干细胞合成分泌胶原纤维，释放基质小泡，并出现钙盐沉积，形成丛毛球状钙球，最终形成骨组织。结论：在旋转式细胞培养系统中，骨髓基质干细胞-PGA支架结构具有形成类似活体骨组织特征的组织工程化骨的潜能。     

对比研究经颈动脉和立体定位注射骨髓间充质干细胞治疗缺血性脑卒中

目的探讨安全高效移植骨髓间充质干细胞(mensenchymal stem cells,MSCs)治疗脑缺血的方法.方法采用连续传代培养的方法纯化MSCs,Brdu标记后分别经颈动脉(1×104/μl,200 μl)和立体定位(1×105/μl,10 μl)注射至大鼠脑缺血2 h再灌注1 d模型,各自设立对照组,观察术后神经功能评分以及脑部Brdu阳性细胞的分布.结果经颈动脉注射组较立体定位注射组爬杆实验评分低(P＜0.05),Brdu阳性细胞存活多,迁移范围更广.结论 MSCs具有卒中后脑保护作用,而经颈动脉的给药方式优于立体定位注射.