CRISPR系统促进脂肪干细胞成骨分化与抑制成脂分化的研究

本研究旨在优化组织培养法分离小鼠脂肪间充质干细胞（adipose-derived stem cells,ASCs）,为研究成骨分化和成脂分化在间充质干细胞分化过程中的相互影响奠定基础。通过细胞形态学观察、细胞生长曲线和流式仪器检测所分离获得的间充质干细胞的特性,利用CRISPR-dCas9系统在快速促进间充质干细胞成骨分化的前提下观察其对成脂分化的影响,并通过生化染色、实时荧光定量PCR和免疫细胞学等手段进行分析。结果显示,接种3~5 d后可见细胞从组织块周围爬出,光镜下可见细胞形态多为成纤维细胞样的梭形细胞,且形态单一均匀,具有较高的爬出率,可以大大提高脂肪间充质干细胞的分离效率;通过CRISPR-dCas9系统激活Runx2和Osterix基因后可以促进间充质干细胞的成骨分化,实时荧光定量PCR及油红O染色结果显示,CRISPR-dCas9系统可以同时抑制间充质干细胞的成脂分化;通过CRISPR-dCas9-KRAB系统同时抑制成骨相关基因Runx2和Osterix后可以促进成脂分化。本研究利用组织贴壁法成功获得了高纯度的脂肪间充质干细胞,具有间充质干细胞的特性和分化能力;利用CRISPR系统可以同时过表达Runx2和Osterix两个基因,可以在进成骨分化的同时抑制成脂分化,表明成脂分化和成骨分化的相关性,为基因编辑在间充质干细胞诱导分化和临床应用方面提供了新的思路和方法。     

骨碎补总黄酮对缺氧环境中犬骨髓间充质干细胞成骨分化潜能的影响

拟研究骨碎补总黄酮对缺氧环境中犬骨髓间充质干细胞(BMSCs)成骨分化潜能的影响.运用骨碎补总黄酮(TFDR)干预低氧浓度(10％)环境中犬BMSCs 4周后诱导成骨分化,倒置显微镜观察茜素红染色BMSCs钙结节形成,比色法检测碱性磷酸酶(ALP)活性水平,流式细胞术检测细胞线粒体膜电位,激光共聚焦显微镜和RT-PCR...     

鸡骨髓间充质干细胞成骨诱导转录组分析

本文旨在通过转录组测序和生物学信息分析探究在鸡的成骨发育过程中可能发挥重要作用的调控基因和生物学通路。从18胚龄明星肉鸡的胫骨获取骨髓间充质干细胞（BMSC）,并进行体外培养与染色鉴定。试验分为试验组和对照组,每组3个生物学重复,试验组将BMSC进行体外成骨诱导分化21 d,对照组不进行处理。分别提取试验组和对照组细胞样品的总RNA,进行转录组分析。结果表明：每个样品平均获得了23 M clean reads数,大约20 M clean reads被比对到鸡的参考基因组上。相比于对照组细胞,试验组筛选到2 715个差异表达基因,包含1 437个上调的差异基因,1 278个下调的差异基因。GO富集分析表明,差异基因主要富集在骨骼系统发育、骨矿化、骨化以及整合素结合等相关功能;KEGG通路主要富集在细胞的焦点黏着、物质合成及能量代谢以及细胞外基质受体相互作用等相关通路。在20条骨发育相关的GO条目或KEGG通路中总共富集到182个基因,其中上调的基因81个,下调的基因101个。通过查找NCBI、Web of Science等相关数据库以及文献,对BMSC成骨分化的过程中发挥重要作用的基因进...     

猪骨髓间充质干细胞分离培养和诱导分化脂肪细胞

采用全骨髓培养法分离猪骨髓间充质干细胞(Mesenchymal stem cells,MSCs)并传代培养;取第4代纯化的MSCs在成脂诱导培养基中诱导分化;分化的成脂细胞用形态学和油红O染色法进行鉴定;用实时荧光定量PCR(Real-time PCR)检测成脂分化标志基因PPARγ2和LPL mRNA的表达情况。结果显示,分离培养的猪MSCs细胞经连续传代形态上无明显改变;MSCs在成脂分化培养液中诱导分化2d开始有少量脂滴出现,油红O染色成阳性,诱导18d成脂转化率可达59.8%;在诱导分化第5、10、15天时,PPARγ2mRNA相对表达量分别是(5.065±0.159)、(6.268±0.340)、(9.277±0.261),LPL mRNA的相对表达量分别是(10.995±1.473)、(13.130±0.712)、(15.762±0.934)。结果表明,用本诱导条件诱导猪MSCs向脂肪细胞分化,经形态学和油红O染色鉴定,成脂细胞分化率可达60%,且随分化时间的延长,脂肪细胞标志基因表达增加。     

犬脂肪间充质干细胞的分离培养及分化潜能研究

为获得犬脂肪间充质干细胞,本试验取犬腹股沟皮下脂肪组织,分别利用组织培养法和酶消化法分离犬脂肪来源间充质干细胞,对比观察不同来源细胞的形态和增殖特征,并通过诱导液促进细胞向成骨细胞和成脂细胞方向分化,检测其分化潜能。结果表明,通过组织培养法培养的青年犬脂肪组织,可获得大量脂肪间充质干细胞,该细胞生长旺盛,形态均一,可分化为碱性磷酸酶染色阳性的成骨细胞和油红O染色阳性成脂细胞。组织培养法分离培养犬脂肪间充质干细胞操作简单,可为细胞移植治疗等研究提供充足的细胞来源。     

马骨髓间充质干细胞向软骨细胞的诱导分化

试验旨在建立马骨髓间充质干细胞（bone marrow mesenchymal stem cells,BMSCs）细胞系,并诱导其向软骨细胞分化。通过获取马BMSCs,进行细胞培养和纯化,对第3代（P3）细胞进行干细胞特性鉴定,并诱导其向软骨细胞分化,对分化后的细胞染色,并检测其软骨细胞特异性基因的表达。结果显示,获得的马BMSCs表达标记基因Sox2和Nanog,并表达间充质干细胞表面标记因子CD44、CD90和CD105,不表达造血细胞表面标志物CD34和CD45。P3代细胞经诱导培养后形态发生改变,阿尔新蓝染色为阳性,并表达软骨细胞特异基因Col,且其表达量随着诱导分化时间的增加而增高。综上表明,本试验建立了马BMSC细胞系,并成功诱导其分化为软骨细胞,为软骨损伤的干细胞治疗提供了试验依据。     

绵羊骨髓间充质干细胞分离培养与鉴定

旨在分离绵羊骨髓间充质干细胞(sheep bone marrow mesenchymal stem cells, SBMSC),建立绵羊骨髓间充质干细胞系,为相关研究提供种子细胞。取新生健康绵羊肋骨为试验材料,利用贴壁法分离获得SBMSC;取生长良好的P3代细胞通过免疫荧光,进行CD73、CD90、CD105、CD106表型鉴定;取生长良好的P3代细胞分别进行成软骨、成脂、成骨方向的诱导,对诱导结果分别进行阿利新蓝、油红O和茜素红染色,鉴定分化结果。SBMSC呈成纤维样贴壁生长;体外培养P3代细胞表面标记物CD73、CD90、CD105和CD106完全符合标准;P3代细胞经软骨、脂肪、骨方向诱导3周后,经阿利新蓝染色,细胞呈亮蓝色;经油红O染色,细胞质内出现橙红色脂滴;茜素红染色表明聚集的细胞团中央能形成钙化结节。说明SBMSC经体外诱导培养后可向软骨细胞、脂肪细胞和成骨细胞分化,并具有明显的成软骨、成脂和成骨表型,表明SBMSC具有多向分化潜能。通过贴壁培养法建立了SBMSC完整的体外培养体系,为绵羊育种等方面提供种子细胞。     

细胞自噬对犬骨髓间充质干细胞干性的影响

本研究旨在探讨细胞自噬对犬骨髓间充质干细胞（cBMSCs）干性的影响。分离培养cBMSCs,将其分为对照组、使用雷帕霉素促进细胞自噬的雷帕霉素组、使用3-MA抑制细胞自噬的3-MA组,于药物处理12、24、48 h后收集细胞,利用间接细胞免疫荧光法检测自噬微管相关蛋白1轻链3 Ⅱ（LC 3Ⅱ）的蛋白表达水平;荧光定量PCR检测自噬相关基因LC 3、Beclin 1、自噬相关基因7（Atg 7）以及干性相关基因性别决定基因相关转录因子2（Sox 2）、特异AT序列结合蛋白2（Satb 2）mRNA转录水平;通过茜素红染色检测经成骨诱导的cBMSCs的成骨分化能力,通过油红O染色检测经成脂诱导的cBMSCs的成脂分化能力。结果显示：雷帕霉素组的LC 3Ⅱ蛋白表达量上调,3-MA组则为下调。雷帕霉素组干性相关基因与自噬相关基因在不同时间点的表达水平均有不同程度的上调,且随感染时间的延长呈上调趋势;3-MA组干性相关基因与自噬相关基因的mRNA转录水平在不同时间点不同程度降低,且随感染时间延长呈下调趋势。成骨诱导试验中雷帕霉素组cBMSCs形态变化最明显,且矿化面积较大,3-MA组细胞矿化面积小;成脂诱导试验中雷帕霉素组脂滴数量少,3-MA组脂滴数量多且聚集程度高。在一定程度上促进cBMSCs自噬水平可以更好地维护其干性并提高成骨分化能力,为优化治疗中cBMSCs的质量提供理论基础和技术支持。     

骨碎补总黄酮通过调节Wnt信号通路促进低氧环境中犬骨髓间充质干细胞成骨分化的研究

基于Wnt信号通路研究骨碎补总黄酮(GSB)对低氧环境中骨髓间充质干细胞(BMSCs)成骨分化的影响。运用GSB干预低氧浓度(10%)环境中成骨分化培养的BMSCs 4周,试验分为常氧对照组、低氧组、GSB干预组,观察BMSCs钙结节沉积和碱性磷酸酶(ALP)活性水平,Western blot检测成骨分化蛋白骨钙素(OCN)、骨桥蛋白(OPN)、Ⅰ型胶原(COLⅠ)和Wnt信号通路相关蛋白GSK-3β、p-GSK-3β、β-Catnine表达水平。结果：与对照组相比,10%低氧浓度抑制BMSCs钙结节形成、ALP活性降低,成骨分化相关蛋白OCN、OPN、COLⅠ表达升高,Wnt信号通路GSK-3β表达降低,p-GSK-3β、β-Catnine表达升高(P<0.05);与低氧组相比,GSB能显著促进低氧浓度中BMSCs钙结节产生、ALP活性升高,OCN、OPN、COLⅠ表达升高,GSK-3β表达升高,p-GSK-3β、β-Catnine表达降低(P<0.05)。研究表明,GSB能够通过抑制Wnt信号通路,促进低氧条件下BMSCs向成骨方向分化。     

脂肪间充质干细胞的研究进展

干细胞(stem cells)不同于成熟细胞。首先是因为它能够在长时间内保持自我更新和扩增的能力。干细胞是未成熟的细胞,不具有组织特性,不发挥与组织相关的细胞功能。其次干细胞能够向多种细胞系分化。干细胞的这些特点使其成为良好的种子细胞来源。胚胎干细胞(ESC)是能够向各种细胞系分     

体外诱导牛BMSC向上皮样细胞分化的研究

为培育转基因肉牛提供种子细胞以及进一步丰富牛骨髓间充质干细胞(bone marrow mesenchymal stem cell,BMSC)的多向分化潜能,利用细胞免疫荧光染色和分子生物学方法,初步探讨表皮生长因子和胰岛素体外诱导牛BMSC向上皮样细胞分化的可能性。利用含细胞因子的诱导液对纯化稳定的P4代牛BMSC进行体外诱导,并对诱导后的细胞进行细胞角蛋白18的细胞免疫荧光观察和细胞角蛋白19的RT-PCR鉴定。结果表明,诱导后细胞经细胞角蛋白18免疫荧光染色后出现明显的荧光。RT-PCR结果显示诱导分化后细胞角蛋白19基因在细胞中表达。因此,在体外,表皮生长因子和胰岛素可诱导牛BMSC初步分化为上皮样细胞。     

镉对体外培养鸡骨髓基质细胞成骨分化的毒性作用

骨是镉毒性作用的主要靶器官之一,但其对鸡骨髓基质细胞(bone marrow stromal cells,BMSCs)增殖和成骨分化的毒性作用仍不清楚.本研究利用差速贴壁纯化法获得鸡BMSCs,加入不同浓度镉处理不同时间,采用CCK-8法检测细胞增殖,碱性磷酸酶(alkaline phosphatase,ALP)和茜素...     

小鼠脂肪间充质干细胞向胰岛素分泌细胞的诱导分化研究

为了通过特定转录因子将小鼠脂肪间充质干细胞(mADSCs)定向诱导分化为胰岛素分泌细胞(IPCs)。本研究分别构建Pdx1(胰十二指肠同源盒基因1)、MafA(V-maf肌肉腱膜纤维肉瘤癌基因同源物A)、NeuroD1(神经分化因子1)3种基因的慢病毒过表达载体,使用293T细胞对3种因子进行慢病毒包装,将3种慢病毒过表达载体以单因子侵染、双因子侵染、三因子联合侵染的方式对mADSCs进行定向分化诱导,于诱导分化第15天对不同方式诱导的IPCs进行检测鉴定,并对不同方式诱导组的IPCs进行高糖刺激,刺激后30~120min检测培养基中含糖量的变化。结果显示,构建的慢病毒过表达载体pHBLV-CMV-IRES-ZsGreen-Pdx1、pHBLV-CMV-PGK-RFPMafA、pHBLV-CMV-PGK-RFP-NeuroD1所含目的片段基因序列与小鼠全基因编码序列完全一致,三种基因慢病毒过表达载体构建成功;诱导分化第15天,三因子联合诱导组所形成的IPCs克隆双硫腙(DTZ)染色呈阳性,并可表达胰岛素生物合成及分泌相关基因;在高糖刺激条件下,三因子联合诱导组糖分解速度、分解量远优于单因子或双因子诱导组。结果表明,Pdx1、MafA、NeuroD1 3种因子联合作用,可以将小鼠脂肪间充质干细胞定向诱导分化为胰岛素分泌细胞,并可在高糖刺激下,有效发挥降糖作用。     

Comparing the osteogenic potential of canine mesenchymal stem cells derived from adipose tissues, bone marrow, umbilical cord blood, and Wharton's jelly for treating bone defects

Alternative sources of mesenchymal stem cells (MSCs) for replacing bone marrow (BM) have been extensively investigated in the field of bone tissue engineering. The purpose of this study was to compare the osteogenic potential of canine MSCs derived from adipose tissue (AT), BM, umbilical cord blood (UCB), and Wharton''s jelly (WJ) using in vitro culture techniques and in vivo orthotopic implantation assays. After canine MSCs were isolated from various tissues, the proliferation and osteogenic potential along with vascular endothelial growth factor (VEGF) production were measured and compared in vitro. For the in vivo assay, MSCs derived from each type of tissue were mixed with β-tricalcium phosphate and implanted into segmental bone defects in dogs. Among the different types of MSCs, AT-MSCs had a higher proliferation potential and BM-MSCs produced the most VEGF. AT-MSCs and UCB-MSCs showed greater in vitro osteogenic potential compared to the other cells. Radiographic and histological analyses showed that all tested MSCs had similar osteogenic capacities, and the level of new bone formation was much higher with implants containing MSCs than cell-free implants. These results indicate that AT-MSCs, UCB-MSCs, and WJ-MSCs can potentially be used in place of BM-MSCs for clinical bone engineering procedures.     

Transplantation of adipose derived mesenchymal stem cells for acute thoracolumbar disc disease with no deep pain perception in dogs

Thirty-four dogs with no deep pain perception due to acute thoracolumbar intervertebral disc disease underwent decompression surgery within 1 week of diagnosis. All dogs underwent hemilaminectomy. Adipose derived mesenchymal stem cells (AD-MSCs) were transplanted into the injured spinal cord parenchyma for the AD-MSCs transplant dogs. Long-term outcome was evaluated at the end of the follow-up period (> 6 months). AD-MSCs combination treatment showed better recovery outcomes compared to decompression surgery alone. These results indicate that this stem cell therapy is a potential therapeutic strategy to overcome the limitations of treatment for spinal cord injury in clinical medicine.     

兔脂肪间质干细胞的分离培养与鉴定

取兔腹股沟皮下脂肪组织，用Ⅰ型胶原酶消化，分离培养脂肪间质干细胞（MSCs），并用免疫组化和体外诱导分化方法对其表面分子标志和多向分化潜能进行鉴定。结果显示，兔脂肪组织中能够分离培养出脂肪MSCs，该类细胞表达CD29、CD44和CD105，不表达CD34、CD45及HLA—DR表面分子标志，并具有可分化为脂肪细胞、神经细胞和成骨细胞的多向分化潜能，证实兔脂肪组织中存在具有多向分化潜能的MSCs。     

Effect of serum-derived albumin scaffold and canine adipose tissue-derived mesenchymal stem cells on osteogenesis in canine segmental bone defect model

Composite biological and synthetic grafts with progenitor cells offer an alternative approach to auto- or allografts for fracture repair. This study was conducted to evaluate osteogenesis of autologous serum-derived albumin (ASA) scaffolds seeded with canine adipose tissue-derived mesenchymal stem cells (Ad-MSCs) in a canine segmental bone defect model. ASA scaffold was prepared with canine serum using cross-linking and freeze-drying procedures. Beta-tricalcium phosphate (β-TCP) was mixed at the cross-linking stage. Ad-MSCs were seeded into the scaffold and incubated for one day before implantation. After 16 weeks, the grafts were harvested for histological analysis. The dogs were divided into five groups: control, ASA scaffolds with and without Ad-MSCs, and ASA scaffolds including β-TCP with and without Ad-MSCs. ASA scaffolds with Ad-MSCs had a significantly larger area of increased opacity at the proximal and distal host cortex-implant interfaces in radiographs 16 weeks after implantation compared to the groups with β-TCP (p < 0.05). Histomorphometric analysis showed that ASA scaffolds with Ad-MSCs had significantly greater new bone formation than other groups (p < 0.05). These results suggest that Ad-MSCs seeded into ASA scaffolds enhanced osteogenesis in the bone defect model, but that β-TCP in the ASA scaffold might prevent penetration of the cells required for bone healing.     

Optimisation of bone marrow aspiration from the equine sternum for the safe recovery of mesenchymal stem cells

Reasons for performing study: Mesenchymal stem cell (MSC) therapy for orthopaedic disease is being used with increasing frequency; there is a need to define a safe, reliable and effective technique for the recovery of MSCs from the sternum of the horse. Objectives: To describe an optimised safe technique for obtaining bone marrow‐derived MSCs from the sternum of the Thoroughbred horse. Methods: The anatomical relationship of the sternum with the heart and internal anatomy was demonstrated in cadavers. Sternal anatomy was evaluated ultrasonographically and after midline sectioning. Sternebrae were examined histologically after aspiration to determine the effect of needle insertion. The quality of the aspirate was evaluated as the number of colony‐forming units from sequential and separately aspirated 5 ml aliquots and assessed for their multipotency using trilineage differentiation. Results: The optimal safe location for the needle was the 5th sternebra because it had a safe dorsoventral thickness and was cranial to the apex of the heart. This sternebra could be reliably identified ultrasonographically. Aspirates could also be obtained from the 4th and 6th sternebrae, although the former is between the front limbs and the latter closer to the heart. Minimal disruption of the internal bony architecture was seen after needle insertion through the thin outer cortex and the first 5 ml aliquot contained the greatest number of colony‐forming units of mesenchymal stem cells with trilineage capabilities. Conclusions: Accurate placement of a Jamshidi needle into the medullary cavity of the 4th–6th individual sternebrae is facilitated by the use of ultrasonography and enables aspiration of bone marrow reliably with minimal damage to the sternum and risk to the horse. Potential clinical relevance: Sternal marrow aspiration as described is a safe and reliable technique to obtain MSCs for orthopaedic cell‐based therapies.