In vitro Culture of Bone Marrow Mesenchymal Stem Cells in Rats and Differentiation into Retinal Neural-like Cells

In order to study the in vitro culture and expansion of bone marrow mesenchymal stem cells in rats （rMSCs） and the possibility of rMSCs differentiation into retinal neural cells, the bone marrow-derived cells in SD rats were isolated and cultured in vitro. The retinal neural cells in SD rats were cultured and the supernatants were collected to prepare conditioned medium. The cultured rMSCs were induced to differentiate by two steps. Immunofluorescence method and anti-nestin, anti-NeuN, anti-GFAP and anti-Thyl. 1 antibodies were used to identify the cells derived from the rMSCs. The results showed that the in vitro cultured rMSCs grew well and expanded quickly. After induction with two conditioned media, rMSCs was induced to differentiate into neural progenitor cells, then into retinal neural-like cells which were positive for nestin, NeuN, GFAP and Thyl. 1 detected by fluorescence method. The findings suggested that rMSCs could be culture and expanded in vitro, and induced to differentiate into retinal neural-like cells.

Biological Characteristics of Human Bone Marrow Mesenchymal Stem Cell Cultured in Vitro

Some biological characteristics of human bone marrow mesenchymal stem cells (MSCs) cultured in vitro were observed. hMSCs were isolated from bone marrow and purified by density gradient centrifugation method, and then cultured in vitro. The proliferation and growth characteristics of hMSCs were observed in primary and passage culture. MSCs of passage 3 were examined for the purify by positive rate of CD29 and CD44 through flow cytometry. Human bone marrow MSCs showed active proliferation capacity in vitro. The purify of MSCs separated by our method was higher than 90 %. It was concluded that hMSCs have been successfully cultured and expanded effectively. It provided a foundation for further investigation and application of MSCs.

Culture conditions for equine bone marrow mesenchymal stem cells and expression of key transcription factors during their differentiation into osteoblasts

Background： The use of equine bone marrow mesenchymal stem cells （BMSC） is a novel method to improve fracture healing in horses. However, additional research is needed to identify optimal culture conditions and to determine the mechanisms involved in regulating BMSC differentiation into osteoblasts. The objectives of the experiments were to determine： 1） if autologous or commercial serum is better for proliferation and differentiation of equine BMSC into osteoblasts, and 2） the expression of key transcription factors during the differentiation of equine BMSC into osteoblasts. Equine BMSC were isolated from the sterna of 3 horses, treated with purchased fetal bovine serum （FBS） or autologous horse serum （HS）, and cell proliferation determined. To induce osteoblast differentiation, cells were incubated with L-ascorbic acid-2-phosphate and glycerol-2-phosphate in the presence or absence of human bone morphogenetic protein2 （BMP2）, dexamethasone （DEX）, or combination of the two. Alkaline phosphatase （ALP） activity, a marker of osteoblast differentiation, was determined by ELISA. Total RNA was isolated from differentiating BMSC between d 0 to 18 to determine expression of runt-reloted tronscrJption foctor2 （Runx2）, osterix （Osx）, and T-box3 （Tbx3）. Data were analyzed by ANOVA. Results： Relative to control, FBS and HS increased cell number （133 ± 5 and 116 ± 5%, respectively; P 〈 0.001） and 5-bromo- 2＇-deoxyuridine （BrdU） incorporation （167 ± 6 and 120 ± 6%, respectively; P 〈 0.001）. Treatment with DEX increased ALP activity compared with control （1,638 ± 38%; P 〈 0.001）. In the absence and presence of Dex, BMP-2 did not alter ALP activity （P 〉 0.8）. Runt-reloted transcription foctor2 expression increased 3-fold （P 〈 0.001） by d 6 of culture. Osterix expression increased 94old （P 〈 0.05） by d 18 of culture. Expression of Tbx3 increased 1.8-fold at d 3 （P 〈 0.01）; however expression was reduced 4-fold at d 18 （P 〈 0.01）. Conclusions： Dexamethasone, but not BMP-2, is required for differentiation of equine BMSC into osteoblasts. In addition, expression of Runx2 and osterix increased and expression of Tbx3 is reduced during differentiation.

Pre-degenerated peripheral nerves co-cultured with bone marrow-derived cells: a new technique for harvesting high-purity Schwann cells

Schwann cells play an important role in the peripheral nervous system, especially in nerve repair following injury, so artificial nerve regen- eration requires an effective technique for obtaining purified Schwann cells. In vivo and in vitro pre-degeneration of peripheral nerves have been shown to obtain high-purity Schwann cells. We believed that in vitro pre-degeneration was simple and controllable, and available for the clinic. Thus, we co-cultured the crushed sciatic nerves with bone marrow-derived cells in vitro. Results demonstrated that, 3 hours after injury, a large number of mononuclear cells moved to the crushed nerves and a large number of bone marrow-derived cells infiltrated the nerve segments. These changes promoted the degradation of the nerve segments, and the dedifferentiation and proliferation of Schwann cells. Neural cell adhesion molecule and glial fibrillary acidic protein expression were detected in the crushed nerves. Schwann cell yield was 9.08 ± 2.01 ×104/mg. The purity of primary cultured Schwann cells was 88.4 ± 5.79%. These indicate a successful new method for ob- taining Schwann cells of high purity and yield from adult crushed sciatic nerve using bone marrow-derived cells.

Osteogenic Differentiation of Bone Mesenchymal Stem Cells Regulated by Osteoblasts under EMF Exposure in a Co-culture System

This study examined the osteogenic effect of electromagnetic fields （EMF） under the simulated in vivo conditions. Rat bone marrow mesenchymal stem cells （BMSCs） and rat osteoblasts were co-cultured and exposed to 50 Hz, 1.0 mT EMF for different terms. Unexposed single-cultured BMSCs and osteoblasts were set as controls. Cell proliferation features of single-cultured BMSCs and osteoblasts were studied by using a cell counting kit （CCK-8）. For the co-culture system, cells in each group were randomly chosen for alkaline phosphatase （ALP） staining on the day 7. When EMF exposure lasted for 14 days, dishes in each group were randomly chosen for total RNA extraction and von Kossa staining. The mRNA expression of osteogenic markers was detected by using real-time PCR. Our study showed that short-term EMF exposure （2 h/day） could obviously promote prolifera- tion of BMSCs and osteoblasts, while long-term EMF （8 h/day） could promote osteogenic differen- tiation significantly under co-cultured conditions. Under EMF exposure, osteogenesis-related mRNA expression changed obviously in co-cultured and single-cultured cells. It was noteworthy that most osteogenic indices in osteoblasts were increased markedly after co-culture except Bmp2, which was increased gradually when ceils were exposed to EMF. Compared to other indices, the expression of Bmp2 in BMSCs was increased sharply in both single-cultured and co-cultured groups when they were exposed to EMF. The mRNA expression of Bmp2 in BMSCs was approximately four times higher in 8-h EMF group than that in the unexposed group. Our results suggest that Bmp2-mediated cellular interaction induced by EMF exposure might play an important role in the osteogenic differ- entiation of BMSCs.

Bone Marrow Transplant Long-Term Survivors’ Satisfaction with Quality of Life: Comparison with a Control Group

Purpose: To evaluate the global quality of life (QoL) of survivors with 10-year or more post-transplant, and to identify risk factors that interfere with well-being. Methods: This is a prospective analytic transversal study with 214 survivors of Bone Marrow Transplant (BMT) and 264 healthy people identified among blood donors, treated as the control group, of both sexes, 18 years or older. The protocol includes a demographic-socioeconomic questionnaire, World Health Organization Quality of Life (WHOQOL) and the Karnofsky Performance Status Scale. Results: 53.7% of the survivor group members are satisfied with their QoL. A similar result can be found in the control group (54.2%). Chronological maturity, anxiety, sexual difficulty, and being a provider are factors that interfere negatively in the QoL of male survivors. In female survivors, the risk factors are anxiety, low educational level, not having a stable partner, being a provider, and not being Caucasian. Conclusions: Survivors are as satisfied with their QoL as the control group. QoL is understood as a perceptive process composed of objective (functional and relational capacity) and subjective phenomenon (perceptive composition).

Dynamic culture of a thermosensitive collagen hydrogel as an extracellular matrix improves the construction of tissue-engineered peripheral nerve

Tissue engineering technologies offer new treatment strategies for the repair of peripheral nerve injury, hut cell loss between seeding and adhesion to the scaffold remains inevitable. A thermosensitive collagen hydrogel was used as an extracellular matrix in this study and combined with bone marrow mesenchymal stem cells to construct tissue-engineered peripheral nerve composites in vitro. Dynamic culture was performed at an oscillating frequency of 0.5 Hz and 35° swing angle above and below the horizontal plane. The results demonstrated that bone marrow mesenchymal stem cells formed membrane-like structures around the poly-L-lactic acid scaffolds and exhibited regular alignment on the composite surface. Collagen was used to fill in the pores, and seeded cells adhered onto the poly-L-lactic acid fibers. The DNA content of the bone marrow mesenchymal stem cells was higher in the composites constructed with a thermosensitive collagen hydrogel compared with that in collagen I scaffold controls. The cellular DNA content was also higher in the thermosensitive collagen hydrogel composites constructed with the thermosensitive collagen hydrogel in dynamic culture than that in static culture. These results indicate that tissue-engineered composites formed with thermosensitive collagen hydrogel in dynamic culture can maintain larger numbers of seeded cells by avoiding cell loss during the initial adhe-sion stage. Moreover, seeded cells were distributed throughout the material.

Dorsal root ganglion neurons promote proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells

Preliminary animal experiments have confirmed that sensory nerve fibers promote osteoblast differentiation, but motor nerve fibers have no promotion effect. Whether sensory neurons pro- mote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells remains unclear. No results at the cellular level have been reported. In this study, dorsal root ganglion neurons （sensory neurons） from Sprague-Dawley fetal rats were co-cultured with bone marrow mesenchymal stem cells transfected with green fluorescent protein 3 weeks after osteo- genic differentiation in vitro, while osteoblasts derived from bone marrow mesenchymal stem cells served as the control group. The rat dorsal root ganglion neurons promoted the prolifera- tion of bone marrow mesenchymal stem cell-derived osteoblasts at B and 5 days of co-culture, as observed by fluorescence microscopy. The levels of mRNAs for osteogenic differentiation-re- lated factors （including alkaline phosphatase, osteocalcin, osteopontin and bone morphogenetic protein 2） in the co-culture group were higher than those in the control group, as detected by real-time quantitative PCR. Our findings indicate that dorsal root ganglion neurons promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells, which pro- vides a theoretical basis for in vitro experiments aimed at constructing tissue-engineered bone.

Gender difference in the neuroprotective effect of rat bone marrow mesenchymal cells against hypoxiainduced apoptosis of retinal ganglion cells

Bone marrow mesenchymal stem cells can reduce retinal ganglion cell death and effectively prevent vision loss. Previously, we found that during differentiation, female rhesus monkey bone marrow mesenchymal stem cells acquire a higher neurogenic potential compared with male rhesus monkey bone marrow mesenchymal stem cells. This suggests that female bone marrow mesenchymal stem cells have a stronger neuroprotective effect than male bone marrow mesenchymal stem cells. Here, we first isolated and cultured bone marrow mesenchymal stem cells from female and male rats by density gradient centrifugation. Retinal tissue from newborn rats was prepared by enzymatic digestion to obtain primary retinal ganglion cells. Using the transwell system, retinal ganglion cells were co-cultured with bone marrow mesenchymal stem cells under hypoxia. Cell apoptosis was detected by flow cytometry and caspase-3 activity assay. We found a marked increase in apoptotic rate and caspase-3 activity of retinal ganglion cells after 24 hours of hypoxia compared with normoxia. Moreover, apoptotic rate and caspase-3 activity of retinal ganglion cells significantly decreased with both female and male bone marrow mesenchymal stem cell co-culture under hypoxia compared with culture alone, with more significant effects from female bone marrow mesenchymal stem cells. Our results indicate that bone marrow mesenchymal stem cells exert a neuroprotective effect against hypoxia-induced apoptosis of retinal ganglion cells, and also that female cells have greater neuroprotective ability compared with male cells.

Study on expresion of adherent proteins related to regulation of hematopoiesis in long-term cultured human bone marrow stromal cells

Abstract Objective To study the molecular basis of bone marrow stromal cell supporting hematopoiesis. Methods Immunoelectron micrscopic ocalization of adherent protein related to regulation of hematopoiesis was performed by immunocolloidal gold labelling technique in the adhernt layer of longterm cultured human hone marrow stromal cells (LTCHBMSC). Results Adherent proteins were found to be expressed on LTCHBMSC. Double labelling revealed co expression of these proteins and some specific markers for endothelial cells (vWF) and fibroblasts (Fb sp). It was suggested that endothelial cells and fibroblasts in LTCHBMSA could synthesize and secrete adherent proteins, which bound to the surface of stromal cells and extracellular matrix. Conclusion Adherent proteins and all kinds of hematopoietic growth factors secreted by stromal cells constitute a complex network supporting hematopoiesis. Study on the coagulant activity of human blood monocytes. Jia Xiaomei, Zheng Huan, Wang Jing, et al. Institute of Hematology, Beijing People's Hospital, Beijing Medical University, Beijing 100044, China. Chin J Hematol 1997; 18(9) 474 476. Objective To investigate the coagulant and fibrinolytic activities of human blood monocytes. Methods Cultured monocytes (2.8×10 6 cells) were refrigerated at 20℃ and then thawed and centrifuged. Blood coagulant factors activities in the upper and lower layer of the supernatant were assayed and compared with that in the supernatant of white blood cells (containing 2.8×10 6 cells). Results There were factors Ⅱ, Ⅶ, Ⅸ, Ⅹ, Ⅴ, and tissue factor activities in the supernatant, Ⅹ Ⅲ A: Ag was 2.1%, Ⅹ Ⅲ S: Ag: 2.8%, while t PA: A and PAI: A were undetectable. In the lower layer there was no specific expression of blood coagulant factors. Conclusion There were coagulant activities in the supernatant containing the membrane and cytoplasma of monocytes.

淫羊藿苷含药血清促进3种细胞共培养体系中软骨细胞增殖和干细胞成软骨分化

背景:关节软骨损伤修复能力十分有限,组织工程技术为修复受损软骨提供了新的治疗方案,其中软骨细胞、骨髓间充质干细胞和滑膜间充质干细胞之间的相互影响和诱导作用是自体软骨损伤愈合的基础。目的:构建软骨细胞-骨髓间充质干细胞-滑膜间充质干细胞共培养体系用以模拟软骨细胞体内微环境,并探究其最佳细胞接种比例,同时观察淫羊藿苷含药血清对该体系中软骨细胞增殖和干细胞成软骨分化的影响。方法:提取、培养、鉴定大鼠膝关节软骨细胞、骨髓间充质干细胞和滑膜间充质干细胞,按不同细胞接种比例构建软骨细胞-骨髓间充质干细胞-滑膜间充质干细胞非接触共培养体系,共培养72 h后观察软骨细胞增殖活性和表型能力,选择综合效应最佳的共培养体系;用淫羊藿苷溶液(0.25 mg/m L)灌胃新西兰大白兔制备淫羊藿苷含药血清,对照组共培养体系用含体积分数为10%胎牛血清、1%双抗的高糖DMEM培养液培养,实验组共培养体系在此基础之上加入体积分数为10%淫羊藿苷含药血清进行干预,24,48 h后检测两组软骨细胞增殖活性和Ⅱ型胶原表达,14 d后采用免疫荧光染色检测骨髓间充质干细胞、滑膜间充质干细胞成软骨分化情况。结果与结论:(1)3种细胞以不同比例共培养时均可正常贴壁生长,当软骨细胞、骨髓间充质干细胞、滑膜间充质干细胞接种比例为2∶1∶1时,共培养体系中软骨细胞表现出最佳增殖活性和表型能力;(2)与对照组相比,实验组培养24 h后软骨细胞增殖活性和Ⅱ型胶原表达显著升高(P<0.01),48 h后两组仍有差异(P<0.05),培养14 d后两组骨髓间充质干细胞和滑膜间充质干细胞出现明显的软骨分化,部分细胞呈现圆形或椭圆形,胞浆Ⅱ型胶原免疫荧光染色为阳性,实验组荧光强度明显高于对照组(P<0.01);(3)结果表明,以非接触共培养方法可以成功建立软骨细胞-骨髓间充质干细胞-滑膜间充质干细胞共培养体系且细胞比例为2∶1∶1时软骨细胞增殖活性和表型能力最佳;同时淫羊藿苷含药血清具有促进该体系中软骨细胞增殖及骨髓间充质干细胞、滑膜间充质干细胞成软骨分化的作用。

Development of bone marrow mesenchymal stem cell culture in vitro

Objective To review the in vitro development of bone marrow mesenchymal stem cells culture （BM-MSC）.Data sources The data cited in this review were mainly obtained from articles listed in Medline and PubMed. The search terms were “bone marrow mesenchymal stem cell” and “cell culture”.Study selection Articles regarding the in vitro development of BM-MSCs culture, as well as the challenge of optimizing cell culture environment in two-dimensional （2D） vs. 3D.Results Improving the culture conditions increases the proliferation and reduces the differentiation. Optimal values for many culture parameters remain to be identified. Expansion of BM-MSCs under defined conditions remains challenging, including the development of optimal culture conditions for BMSC and large-volume production systems.Conclusions Expansion of BM-MSCs under defined conditions remains challenges, including the development of optimal culture conditions for BMSC and scale-up to large-volume production systems. Optimal values for many culture parameters remain to be identified.

In vitro chondrogenesis of the goat bone marrow mesenchymal stem cells directed by chondrocytes in monolayer and 3-dimetional indirect co-culture system

Background Cartilage injury has a very poor capacity for intrinsic regeneration. The cell-based treatment strategy for the cartilage repair using differentiated bone marrow mesenchymal stem cells （BMSCs） is, however, a promising approach to the chondral repair. This study was aimed to explore the chondrogenic potential of the goat BMSCs in the Transwell co-culture system and the poly-laetide-co-glycolide （PLGA） scaffolds.Methods The BMSCs were isolated from the goat iliac crest while the chondrocytes were obtained from the goat＇s last costal cartilage. In the Transwell co-culture system, the BMSCs co-cultured with chondrocytes were designed as group A,whereas the goat＇s BMSCs induced with the chondrogenic medium were group B. Both groups A and B were the experimental groups, while group C that only contained BMSCs was the control group. In the PLGA scaffolds co-culture system, BMSCs were seeded into the PLGA scaffolds, which were suspended in the 24-well plate, and the control group was established by presence or absence of chondrocytes at the bottom of the 24-well plate. Toluidine blue staining,Alcian blue staining, collagen Ⅱ immunofluoresence, collagen Ⅱ immunochemical staining, collagen Ⅰ, collagen Ⅱ, COL2a Q-PCR and osteopontin Q-PCR were used to examine the chondrogenic conditions as well as the expressions of chondrogenic and osteogenic genes.Results Cells isolated from the aspirates of the goat bone marrow proliferated rapidly and gained characteristics of stem cells in Passage 4. However, the differentiations of chondrocytes were not apparent in Passage 3. The results from Toluidine blue staining, collagen Ⅱ immunofluoresence and PCR showed the transformation of BMSCs to chondrocytes in the Transwell co-culture system and PLGA scaffolds. Although the cartilage gene expressions were upgraded in both chondrogenesis group and co-culture system, the osteopontin gene expression, which represents osteogenic level, was also up-regulated.Conclusions The Transwell co-culture system and the PLGA scaffolds co-culture system can promote the chondrogenic differentiation of the goat＇s BMSCs, while up-regulated osteopontin gene expression in the Transwell co-culture system implies the osteogenic potential of BMSCs.

EXPERIENCE ON HLA TYPING FOR ALLOGENEIC MARROW TRANSPLANTATION IN 217 MEMBERS OF 30 FAMILIES

From April 1978 to Oct 1990, 217 members of 30 families who requiredallogeneic marrow transplantation were examined for HLA typing, with HLA standardantiserum and mixed lymphocyte culture (MLC). The following conclusions could bedrawn: (1) when the HLA-A, B, C loci between donor and recipient were identical, theD locus also was generally identical too, but, in some rare cases the HLA-A, B, C wereidentical while the D locus remained different detected by MLC SI which wassignificantly increased; (2) in addition to twin, the sib were the main candidates of donorsin allogeneic marrow transplantation, however, if the phenotype of children was compati-ble to that of their parents with no significant stimulation in MLC, the parents could alsobe considered as a donor; (3) if the HLA-A, B, C typing was identical between fatherand motaher, the parents can also be considered as an eligible donor. Using HLA-A, B,C, DR and D loci identical sibs as donor, 9 of 11 cases (aplastic anemia 9 cases andANLL-M2 2 cases who received allogeneic marrow transplantation) had the evidence ofengraftment. Much attention should be paid to the difference of the minorhistocompatibility antigens, such as sex associated antigen between donor and recipient, be-cause even in 11 cases with HLA-A, B, C, DR and D loci identical sibs as donors formarrow transplantation, 5 cases still had the manifestation of GVHD in various degree,4/5 died of severe GVHD.

长期传代培养对骨髓间充质干细胞生物学特性的影响

背景:人骨髓间充质干细胞体外长期传代培养后是否能保持其生物学特性、能量代谢方式和多向分化潜能等仍存在争议,有待于进一步全面系统研究。目的:观察体外长期传代培养对骨髓间充质干细胞生物学特性的影响。方法:人骨髓间充质干细胞体外培养至第5,10,15代,MTT法检测细胞增殖能力,流式细胞仪检测细胞周期;成脂、成骨、成软骨诱导分化检测细胞多向分化潜能;划痕实验和Transwell侵袭实验检测细胞迁移和侵袭能力;能量代谢分析仪检测细胞线粒体氧化磷酸化和糖酵解能力;β-半乳糖苷酶染色检测细胞衰老情况;Western blot检测细胞衰老标记蛋白p21、p16、p53表达。结果与结论:第5,10,15代骨髓间充质干细胞均呈贴壁生长,第15代细胞体积增大,增殖能力降低,S期细胞百分比减少(P<0.05);随着传代次数的增加,细胞划痕愈合和侵袭能力逐渐减弱(P<0.05),成脂、成骨和成软骨分化潜能未见显著性差异,细胞线粒体氧化磷酸化和糖酵解能力逐渐降低(P<0.05)。随着传代次数的增加,β-半乳糖苷酶染色阳性细胞增多(P<0.05),衰老标记蛋白p21、p16、p53表达逐渐增加(P<0.05)。结果表明:长期传代培养的骨髓间充质干细胞的生物学特性发生变化,第10代以后骨髓间充质干细胞可能由于衰老导致活性降低。采用第10代以内的骨髓间充质干细胞更适合于临床研究/治疗。

大鼠骨髓单个核细胞诱导扩增为内皮祖细胞的细胞分离方法、接种数目、培养瓶包被条件

目的筛选大鼠骨髓单个核细胞(BMMNCs)诱导扩增为内皮祖细胞(BM-EPCs)的细胞分离方法、接种数目、培养瓶包被条件,构建一个高效、高产量、高纯度的骨髓来源BM-EPCs分离培养诱导扩增方法。方法取2周龄雄性SD大鼠,脱颈处死后分离大鼠双侧胫骨和股骨,收集骨髓细胞悬液。配制30%、50%、60%和70%浓度的Percoll细胞分离液,通过Percoll密度梯度离心法分离出大鼠BMMNCs种子细胞,并计算活细胞比例。将获得的BMMNCs分为1×10^(5)、5×10^(5)、1×10^(6)、2.5×10^(6)、5×10^(6)、1×10^(7)六个组别,分别接种于25 cm^(2)无菌培养瓶中,培养7 d后镜下观察各组细胞集落形成数目,并计算每10^(6)细胞的集落形成数。运用Graphpad prism9.5软件进行Logistic拟合曲线,根据相关系数R^(2)确定相关性,根据其P值将有统计学差异的接种数目纳入范围,随后使用R语言编程定义计算函数,根据已知种子细胞总数及相关性函数限制下,通过迭代寻找最佳的BMMNCs细胞接种数目。分别配制20、50、100 nmol/L浓度的人纤连蛋白(FN)溶液,以不添加FN的空白溶液为对照,分别包被空白培养瓶2、6、12、24 h,将收集的48 h未贴壁BMMNCs接种于FN包被的各培养瓶中,静置培养3 d后计算各组集落形成数目,确定FN包被的最佳浓度与时间。接种48 h未贴壁BMMNCs于25 cm^(2)培养瓶底,使用EGM-2完全培养基定向诱导,于显微镜下观察集落形成及诱导扩增进程。取培养14 d的BM-EPCs,分别采用双阳性染色法和流式细胞术鉴定BM-EPCs的纯度。结果使用Percoll分离法可把BMMNCs细胞清晰的分为5层,其中30%与50%Percoll细胞分离层之间为BMMNCs活细胞比率最高。BMMNCs的最优接种数目为2.5×10^(6)个。以50 nmol/L的FN溶液包被24 h或以100 nmol/L的FN溶液包被6 h皆可有效促进细胞集落形成。细胞接种7 d后获得形态良好的铺路石样细胞并建立生长优势,表明BMMNCs已经诱导成为形态良好的BM-EPCs。Dil-Ac-LDL/FITC-UEA-1双阳性细胞占比为91.89%±5.77%,CD31+KDR阳性率为90.73%±0.61%、CD14阳性率为0.53%±0.17%、CD45阳性率0.77%±0.34%,说明获得的BM-EPCs纯度良好。结论大鼠BMMNCs诱导扩增为BM-EPCs过程中,可使用Percoll密度梯度离心法分离BMMNCs,BMMNCs的最优细胞接种数目为2.5×10^(6)个,细胞培养瓶包被条件为以50 nmol/L的FN溶液包被24 h或以100 nmol/L的FN溶液包被6 h,分离培养诱导获得的BM-EPCs形态和纯度均良好。

不同条件下小鼠肺泡巨噬细胞体外培养的实验研究

目的:应用文献报道的肺泡巨噬细胞(AMs)体外培养方法,利用GM-CSF、TGF-β和PPAR-γ激动剂罗格列酮(简称GTR)培养体系,分析不同年龄小鼠、不同来源前体细胞产生AM样细胞或AMs的特征。方法:收取不同周龄小鼠支气管肺泡灌洗液(BALF)、骨髓单个核细胞以及胚胎15~17 d小鼠肝脏单个核细胞,种入12孔板,置于GTR体系中培养。流式细胞术检测产出细胞AM表面标志分子F4/80、CD11b、CD170和CD11c表达。结果:培养后,光镜下BALF来源细胞基本呈圆形,骨髓来源细胞近半呈圆形,胎肝来源细胞85%左右呈圆形。4周龄小鼠BALF-AMs比例接近90%,比例和数量均随小鼠年龄增加而增加,12周龄小鼠BALF-AMs数量接近1×106个。4周龄小鼠骨髓源AM样细胞比例不到20%,8周龄和12周龄小鼠比例为40%~45%,数量随小鼠年龄增加而增加,12周龄小鼠骨髓源AM样细胞数量约为0.8×106个/孔。胎肝源AM样细胞比例约为84%,1个孔产出的AM样细胞约为4×106个。结论:不同年龄小鼠、不同来源前体细胞产生AM样细胞或AMs的纯度和数量有较大差别,应根据具体研究要求选择合适方法。

骨髓细胞体外成骨能力的实验研究

通过体外矿化条件观察培养兔骨髓细胞的成骨能力，结果显示：①第３代骨髓细胞碱性磷酸酶染色，７％～８％阳性；②倒置显微镜下观察，细胞传代５～６ｄ后，长满培养瓶的底部，约１０ｄ开始叠层生长，为局灶状，中央出现较多颗粒样改变，１４～１５ｄ时，培养瓶底部肉眼可见白色小结节形成，并逐渐增大；③细胞连续培养３０ｄ，Ｖｏｎ－Ｋａｏｓａ染色显示有局灶状钙盐沉积；④ＳＥＭ观察，细胞呈叠层生长，形成粗大的胶原纤维束，上有钙盐沉淀，３０ｄ时，形成骨小梁样结构。上述结果表明。

成人骨髓源性神经干细胞诱导分化实验研究

为探讨成人骨髓分离培养神经干细胞的可行性和有效性 ,无菌条件下行骨穿 ,梯度密度离心分离获取成人骨髓源细胞 ,以“CYTOKINE·神经干细胞培养液”培养 ,确定神经干细胞的最佳体外生存环境。以细胞克隆方法判断神经干细胞增殖情况 ;以NESTIN、NSE及GFAP免疫细胞化学方法分别鉴定神经干细胞、神经元和神经胶质细胞。细胞培养所涉及的细胞因子主要有GDNF(2 0ng/ml)、LIF(10ng/ml)和RA(0 5 μg/ml)等。结果发现 ,成人骨髓源细胞在相应培养条件下快速分裂增殖为大而圆并含粗大胞质颗粒的神经干细胞 ,后者形成细胞球 (或称“神经球”) ,该细胞球表达特殊的神经干细胞NESTIN抗原 ;若进一步将这些细胞球分离成单细胞并重新以克隆密度培养 ,单个的细胞又很快形成新的神经球。神经干细胞球进一步分化 ,可见到有的细胞胞体增大并出芽 ,逐渐发育成为较成熟的长突起细胞 ,长突起相互连接、交织成网并建立有神经纤维样联系 ,表达NSE或GFAP抗原。说明成年人骨髓在一定条件诱导下可以生成神经干细胞 ;

小鼠骨髓间质干细胞的生物学特点及分化潜能鉴定

目的 建立一种体外分离、培养和鉴定小鼠骨髓间质干细胞的方法 ,探讨体外培养中间质干细胞的一些生物学特点 ,为利用MSCs促进创伤修复提供实验基础。方法 分离 5～ 6周龄的小鼠胫骨、股骨 ,用预冷的IMDM培养基冲洗出骨髓 ,经密度梯度离心得到骨髓单个核细胞 ,接种后 1 2～ 1 6d形成单层贴壁的成纤维状细胞。体外多向诱导分化鉴定分离的细胞 ,用传代的细胞进行生长曲线的测定、观察其接种贴壁率、检测细胞周期和超微结构。结果 体外传代培养的MSCs具有分化形成成骨和成脂细胞的能力 ;MSCs倍增时间约为 3 8h ,传代后 1 2h贴壁达 90 %以上 ,细胞周期显示有 80 %细胞处于G0 G1 期 ,并用电镜照片显示其超微结构。结论 在本实验条件下 ,体外培养的MSCs具有多向分化潜能 ,体外生长稳定 ,传代后的细胞适应性强 ,增殖较快 ,超微结构和细胞周期表现出较早期细胞特点。