成骨生长肽对大鼠骨髓基质细胞增殖和成骨分化的作用

目的：观察成骨生长肽诱导体外培养的大鼠骨髓基质细胞增殖及向成骨分化的作用。方法：取6周龄SD大鼠，贴壁法分离培养骨髓基质细胞，在不同浓度成骨生长肽的诱导下，观察细胞形态变化，绘制骨髓基质细胞生长曲线，碱性磷酸酶和钙结节组织化学染色。结果：成骨生长肽对骨髓基质细胞增殖和成骨分化的作用呈剂量依赖性：成骨生长肽浓度在10^-10及10^-11mol／L时促进骨髓基质细胞增殖，而在10^-8及10^-9mol／L时对骨髓基质细胞的增殖略有抑制作用；成骨生长肽浓度在10^-10及10^-11mol／L时骨髓基质细胞碱性磷酸酶染色基本呈阴性，与对照组相比差异无统计学意义，而在10^-8及10^-9mol／L浓度下可以显著提高骨髓基质细胞碱性磷酸酶染色的阳性率。结论：成骨生长肽可以明显促进大鼠骨髓基质细胞增殖及向成骨细胞分化，其促成骨活性具有显著的浓度依赖性。     

Wound repair by bone marrow stromal cells through growth factor production

We have previously shown that treatment with bone marrow stromal cells (BMSCs) augments the healing of fascial wounds in the rat. However, the biochemical mechanism by which BMSCs improve wound healing was not investigated. Growth factors have been shown to play a key role in repairing damaged tissue. In this study, we investigated whether BMSCs are capable of producing growth factors that play a critical role in healing of the damaged tissue. Growth factor expression in BMSCs stimulated with pro-inflammatory cytokines or wound superfusate was measured by RT-PCR and growth factor-specific quantitative sandwich enzyme-linked immunosorbent assay (ELISA). RT-PCR analysis demonstrated that BMSCs are capable of expressing transforming growth factor beta-1 (TGF-beta1), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) platelet-derived growth factor (PDGF), keratinocyte growth factor (KGF), fibroblast growth factor (FGF), and hepatocyte growth factor (HGF) constitutively or upon stimulation with LPS, IL-1alpha, or TNF-alpha. Quantitative analysis of growth factor production by ELISA showed that BMSCs do not secrete TGF-beta1, EGF or VEGF in response to uninjured fascia tissue superfusate; however, production of these growth factors is significantly increased when cells were stimulated with wound tissue superfusate. The ability of wound to stimulate growth factor production in BMSCs could be detected as early as day 1 and lasted through day 7 after wounding. Thus, growth factor production by BMSCs in response to wound microenvionment suggests that BMSCs might augment wound healing through the responsive secretion of growth factors that enhance angiogenesis and promote wound repair.     

小剂量阿司匹林对去势大鼠骨髓基质干细胞成骨分化的影响

[目的]检测不同浓度低剂量阿司匹林对去势后(OVX)大鼠骨髓基质干细胞成骨分化的影响.[方法]建立SD大鼠去势模型,全骨髓贴壁法培养骨髓基质干细胞(BMSCs),传代4次后进行成骨诱导,建立对照组和不同浓度阿司匹林组(0.25、0.5、1、2及5mmol/L).于不同的培养时间点,倒置显微镜观察并进行MTT检测细胞增殖生长情况;碱性磷酸酶(ALP)试剂盒检测培养细胞上清ALP活性;于诱导7d和21d时分别行细胞碱性磷酸酶染色和茜素红钙化结节染色.[结果]阿司匹林无明显促进BMSCs增殖作用,而大剂量阿司匹林(5 mmol/L)具有抑制BMSCs增殖作用.实验组(0.25、0.5、1、2 mmol/L阿司匹林组)细胞培养上清中ALP浓度较对照组显著增强(P＜0.05);碱性磷酸酶染色(1、2 mmol/L组)阳性表达增强;茜素红染色显示,实验组(0.5、1、2mmol/L组)钙结节数量、钙化面积均高于对照组(P＜0.05).[结论]阿司匹林不能直接促进去势大鼠BMSC增殖活性,但小剂量阿司匹林可显著提高体外培养BMSC成骨活性,增强钙盐沉积,促进钙结节形成.     

Role of epidermal growth factor receptor in osteoblastic differentiation of rat bone marrow stromal cells

In an attempt to understand the role of epidermal growth factor (EGF) and its receptor (EGF-R) in osteoblastic cell differentiation, the changes in [¹²⁵I]-EGF binding capacity, synthesis of EGF-R protein, and expression of EGF-R mRNA were investigated during osteoblastic differentiation of cultured bone marrow stromal cells which were collected from the femora of young adult rats. In addition, the ability of EGF to suppress osteoblastic differentiation was also studied. Dexamethasone at a concentration of 0.1 mM increased the expression of osteoblastic markers by bone marrow stromal cells cultured in alpha-modified minimum essential medium (-MEM) con taining 1% fetal bovine serum (FBS), 50 mg/ml ascorbic acid, and 10 mM -glycerophosphate, as revealed by elevated alkaline phosphatase activity, an increase in osteopontin mRNA expression, and bone nodule formation. This osteoblastic differentiation was accompanied by a decreased expression of EGF-R mRNA, decreased synthesis of EGF-R protein, and a decreased number of EGF-binding sites without any change in affinity. When these cells were incubated with dexamethasone and EGF in combination throughout the culture, they exhibited significantly lower levels of all osteoblastic markers than did dexamethasonetreated cells, indicating suppression of osteoblastic differentiation by EGF. In contrast, EGF treatment of the cells induced expression of EGF-R mRNA. Thus, a decrease in EGF binding associated with osteoblastic differentiation could lead to decreased responsiveness of bone marrow cells to EGF, whereas the EGF-induced increase in expression of EGF-R could facilitate the inhibition of cell differentiation by EGF. These findings suggested that upregulation of EGF-R on bone marrow stromal cells antagonizes their differentiation, and thus possibly functions as a negative regulator of osteoblastic differentiation.     

3D细胞培养和类器官在骨髓源性间充质干细胞成骨分化中的研究进展

类器官（organoids）来源于自体的组织及干细胞,是通过体外3D培养后形成的细胞团块,这种团块具有原始组织及器官的三维结构,并保留了相对应的功能和遗传特征。由于其具有模拟特定机体器官的发育和疾病发生发展的潜能,这一模型在多种药物的筛选和分子机制研究中拥有更多的优势。近年来,已有实验表明骨髓源性间充质干细胞（BMSCs）通过3D培养及成骨分化可以形成骨的类器官,并可以植入机体发挥特定的作用。这种骨类器官模型的构建,不仅可以为骨质疏松等相关疾病研究提供更多方法,还在骨组织移植及修复等组织工程学中发挥重要作用。本文就BMSCs成骨分化的类器官相关3D模型研究进展作一综述,为BMSCs成骨分化的类器官的基础和临床研究提供更多理论依据和思路。     

成骨诱导的兔骨髓基质干细胞成骨活性的表达及维持

目的观察成骨诱导的兔骨髓基质干细胞(BMSCs)体内、外环境下成骨活性的表达及维持。方法观察BMSCs在体外成骨诱导培养条件下的成骨分化特性;构建兔BMSCs与活骨组织共培养模型模拟体内“成骨环境”,将成骨诱导的MSCs置于共培养及普通传代培养条件下进行传代培养,观察经成骨诱导的BMSCs在体外及模拟体内的培养条件下细胞的表型维持情况。结果药物成骨诱导培养的BMSCs,其ALP活性及骨钙素均显著高于普通培养组(P<0.05);经过诱导培养的BMSCs,其Ⅰ型胶原、骨钙素免疫组化阳性。RT-PCR法半定量测定Ⅰ型胶原mRNA,成骨诱导培养的Ⅰ型胶原mRNA表达量明显高于普通传代培养对照组。药物成骨诱导后的细胞在体外普通传代培养传5代后,细胞碱性磷酸酶(ALP)活性、骨钙素水平及Ⅰ型胶原表达稳定维持在较高水平,保持其成骨细胞的表型;在共培养条件下,ALP活性、骨钙素水平Ⅰ型胶原表达保持在高水平,且ALP活性、骨钙素水平在大部分时间点均高于普通传代培养。结论药物成骨诱导培养呈现促BMSCs向成骨方向转化的特点,能使ALP、骨钙素及Ⅰ型胶原表达短期内达到高水平;经成骨诱导的BMSCs在体外或模拟的体内传代培养条件下,均能维持成骨表型,保持成骨活力。     

人脱细胞骨复合骨髓基质细胞成骨活性的实验研究

目的 研究人脱细胞骨(HAB)复合经诱导的骨髓基质细胞的实验效果,观察细胞的黏附和生长情况,并对其成骨活性进行检测。方法 用15％的过氧化氢和乙醚去除人髂骨块内的结缔组织和细胞成分,消毒后制备人脱细胞骨。取材活体或新鲜尸体的骨髓行骨髓基质细胞培养,细胞纯化后加入β-甘油酸钠,地塞米松和抗坏血酸等向成骨方向诱导,并进行对照培养。通过碱性磷酸酶(ALP)和骨钙素(OCN)检测来确定骨髓基质细胞的增殖和分化情况,将诱导的骨髓基质细胞浓缩后复合到制备好的脱细胞骨块内进行复合培养。8d后通过光镜和电镜等形态学观察以及生化指标检测来确定细胞的成骨活性。结果 人髂骨块内细胞清除干净,骨基质保存良好;诱导后的骨髓基质细胞ALP和OCN水平明显高于对照组(P<0.05);复合后的人脱细胞骨培养液中ALP和OCN检测呈阳性;骨髓基质细胞在HAB支架内附着紧密,生长良好。结论 人脱细胞骨复合经诱导的骨髓基质细胞在体外具有有效的成骨功能,是一种较为理想的骨组织工程材料。     

Distinct roles of bone morphogenetic proteins in osteogenic differentiation of mesenchymal stem cells.

Efficacious bone regeneration could revolutionize the clinical management of many bone and musculoskeletal disorders. Bone morphogenetic proteins (BMPs) can regulate the differentiation of mesenchymal stem cells into cartilage, bone, tendon/ligament, and fat lineages. Early data documented the osteogenic potential of rhBMP2 and rhBMP7/OP-1. However, prior to this work that summarized several of our recent studies, no comprehensive analysis had been undertaken to characterize relative osteogenic activity of all BMPs. Using recombinant adenoviruses expressing 14 BMPs, we have demonstrated that, besides BMP2 and BMP7, BMP6 and BMP9 exhibit the highest osteogenic activity both in vitro and in vivo. We further demonstrated that several BMPs may exert synergistic effect on osteogenic differentiation, and that osteogenic BMPs produce a distinct set of molecular fingerprints during osteogenic differentiation. The reported work should expand our current understanding of BMP functions during osteogenic differentiation. It is conceivable that osteogenic BMPs (i.e., BMP2, 4, 6, 7, and 9) may be used to formulate synergistic pairs among themselves and/or with other less osteogenic BMPs for efficacious bone regeneration in clinical settings.     

兔骨髓基质细胞体外成骨分化鉴定及与煅烧骨复合培养的实验研究

目的研究兔骨髓基质细胞体外向成骨细胞分化的生物学特性及其与牛煅烧骨体外复合培养的生物相容性.方法将体外培养1周的兔骨髓基质细胞向成骨细胞诱导分化,于1、2、4周时提取RNA,采用RT-PCR技术检测ALP和I型胶原mRNA表达,并对培养2周的细胞行VonKossa染色观察钙结节形成;另制备细胞-煅烧骨复合物,继续培养1、7、14 d后取出,扫描电镜观察及X射线衍射仪检测.结果体外诱导培养2、4周后,兔骨髓基质细胞成功表达ALT和I型胶原,VonKossa染色可见钙结节形成.扫描电镜及X射线衍射分析证实细胞在煅烧骨表面大量贴附成活,14 d后细胞铺满支架表面,合成并分泌胶原纤维及钙盐.结论兔骨髓基质细胞体外可成功向成骨细胞诱导分化,成骨特性表达佳;与牛煅烧骨体外复合培养显示良好的生物相容性.     

兔骨髓基质细胞的分离培养

目的 为骨组织工程寻找一种理想的种子细胞。方法 采取兔骨髓组织，应用梯度离心获取骨髓基质细胞，体外培养传代，通过光镜、透射电镜及成骨特性的鉴定，观察细胞的形态、生长特点及成骨特性。结果 培养的骨髓基质细胞形态多为三角形或梭形，生长增殖迅速，具有成骨能力，易于定向分化为成骨细胞。结论 自骨髓获得的骨髓基质细胞具有明显的增殖能力和成骨活性，可以做为骨组织工程中比较理想的种子细胞。     

同种异体骨髓基质细胞肌肉内成骨分化的实验研究

目的 观察并探讨同种异体兔骨髓基质细胞在未接受免疫抑制剂的正常兔肌肉内移植后的免疫原性、存活及成骨状况.方法 首先通过兔谱系差异选择供、受体,并采用淋巴细胞反应进一步证实免疫学错配,之后抽取兔骨髓、体外分离培养、获取骨髓基质细胞,体外加矿化条件培养液诱导成骨、并对成骨特性予以鉴定后,将异体骨髓基质细胞移植入受体兔肌肉内,从淋巴细胞转化率、淋巴细胞杀伤活性、组织学检查、种子细胞体内成活及成骨情况等方面检测. 结果 术后各检测时间,异体骨髓基质细胞移植未诱发淋巴细胞大量增殖反应(P>0.05),淋巴细胞杀伤活性与自体组差异无统计学意义(P>0.05),移植区未见到大量炎性细胞浸润,经组织学及免疫组化染色证实异体骨髓基质细胞在受体组织内存活,8周后于异体肌肉中形成骨组织. 结论 同种异体骨髓基质细胞移植,未诱发免疫排斥反应,在无免疫抑制剂应用的情况下,移植细胞在受体肌肉内存活、并形成骨性组织.     

骨髓基质干细胞在骨科应用研究的现状

骨髓基质干细胞（marrow stromal cells,MSCs） 是一类具有独特表型和细胞化学特性的细胞群,有自我复制和多向分化的潜能.将小鼠的MSCs置于体外特定条件诱导培养下,可向多种中胚层和神经外胚层来源的细胞分化,包括成骨细胞、软骨细胞、成肌细胞、肌腱细胞、成纤维细胞、神经细胞、上皮细胞、肝细胞和脂肪细胞等成熟细胞[1].     

新型神经支架材料的构建及其与骨髓基质干细胞复合的实验研究

[目的]研制出一种可用于修复周围神经缺损的组织工程支架材料,并观察体外培养的骨髓基质干细胞在支架材料中的生长情况。[方法]以I型胶原蛋白和明胶通过冷冻干燥技术制备胶原蛋白支架材料。扫描电镜观察内部结构的排列规律及走行,测量其孔径大小、孔隙率等指标。将骨髓基质干细胞复合到胶原蛋白支架材料中共培养5 d后,扫描电镜下观察其在材料内部的生长情况。[结果]构建的材料均为圆柱状,内部为孔径均匀且平行排列的微管结构,体外培养的骨髓基质干细胞成功种植在支架材料上,在材料内部生长良好。[结论]构建的支架材料具有良好的三维空间构形和生物相容性,为神经损伤的修复提供了一种新型的支架材料。     

Isolation, characterisation and osteogenic potential of human bone marrow stromal cells derived from the medullary cavity of the femur

Marrow stromal cells (MSC) are increasingly being introduced in orthopaedic practice as potentially powerful effectors of bone regeneration. Since cell recovery of MSC is affected by a high degree of individual variability, sources for collecting adequate amounts of safe and effective MSC under routine conditions are needed. We analysed if femoral bone marrow, which is usually discarded during total hip arthroplasty procedures, is a reliable source of MSC to enhance bone healing and regeneration. Mononuclear cells were isolated, assayed for typical MSC markers, harvested under appropriate culture conditions and evaluated for their ability to differentiate into osteoblasts. Cell recovery and osteogenic potential were independent from donor gender or age, suggesting that elderly individuals are eligible for autologous cell therapy. Although heterogeneous, the pool of MSC recoveredfrom femoral marrow without further in vitro selection or manipulation proved highly effective in proliferating and differentiating along the osteogenic lineage. In conclusion, this source of MSC offers a valuable tool to be used to promote osteogenesis and implant fixation.     

聚羟基丁酸酯复合骨髓基质细胞构建组织工程骨修复兔下颌骨缺损

目的：探讨以聚羟基丁酸酯（PHB）作为骨组织工程支架的可行性.方法：体外培养兔骨髓基质细胞（BMSCs）,使其向成骨细胞分化后接种于PHB支架上,植入兔下颌角骨缺损中,以单纯缺损、单纯植入材料、植入新鲜骨髓加材料作为对照.4、8、1 2、24周分别处死各组家兔2只,行大体标本、X线摄片、组织学及扫描电镜观察新骨形成情况.结果：实验组24周大部分材料被骨性组织取代,修复骨缺损效率较对照组高.结论：PHB可以作为组织工程材料中的一种来修复骨缺损.     

骨髓基质干细胞成骨的研究进展

组织工程学是生命科学中新兴学科，是生物医学工程领域的一个快速发展的新方向。骨组织工程学是骨外科学主要发展方向之一。骨髓基质干细胞有明确的成骨作用，其特点为来源丰富、提取方便、体外扩增迅速、易于成骨诱导、可导入标记性或治疗性基因，因此认为骨髓基质干细胞是骨组织工程学中理想的种子细胞。本文就骨髓基质干细胞成骨进展作一综述。     

外泌体非编码RNA调控骨髓间充质干细胞成骨分化的研究进展

骨髓间充质干细胞是一种具有自我更新和多项分化潜能的干细胞,针对其成骨分化作用的研究对骨缺损、骨再生等骨组织工程有重大意义。外泌体内含miRNA、lncRNA、circRNA等非编码RNA,可通过多种途径调控骨髓间充质干细胞的成骨分化,其研究成果可以为促进成骨分化、治疗骨质疏松症等疾病提供新的靶点与方法。本文就外泌体中miRNA、lncRNA以及circRNA对BMSCs成骨分化作用机制的研究进展做一综述。