脂肪间充质干细胞的成骨诱导分化

目的　研究脂肪间充质干细胞 (MSCs)在特定培养条件下向成骨细胞分化 ,探讨其作为骨组织工程的种子细胞的可行性。方法　取 3周龄Lewis大鼠的腹股沟脂肪垫 ,消化法获得脂肪MSCs,用成骨诱导培养基诱导其向成骨细胞分化 ,组织化学染色、免疫细胞化学染色和Westernblotting检测细胞分化的情况。结果　从成体大鼠脂肪组织中培养出脂肪MSCs,能大量稳定增殖传代。在地塞米松、抗坏血酸、β-甘油磷酸钠的诱导下 ,脂肪MSCs的ALP活性增高 ,VonKossa染色出现钙结节 ,OPN、BMP - 2免疫细胞化学染色阳性 ,Westernblotting检测到诱导后细胞OPN、BMP - 2的表达 ,且随诱导时间延长表达增强。结论　从脂肪组织中可获得具有多分化潜能的MSCs,并能在体外稳定增殖传代 ,经诱导后可分化为脂肪细胞和成骨细胞 ,有可能成为骨组织工程较理想的种子细胞之一     

不同浓度地塞米松诱导脂肪干细胞成骨分化的实验研究

目的地塞米松是MSCs成骨诱导分化的基础试剂,探讨诱导脂肪干细胞(adipose-derived stem cells,ADSCs)成骨分化过程中地塞米松的优选浓度,为进一步骨组织工程研究提供理论依据。方法 3月龄清洁级健康新西兰大白兔5只,雌雄不限,体重2～3 kg。取腹股沟区皮下脂肪4～6 mL,采用胶原酶消化离心贴壁法分离培养ADSCs,取第3代细胞进行实验。倒置相差显微镜观察细胞形态变化;联合CD44、CD106免疫荧光染色和成脂诱导分化鉴定ADSCs。调整细胞密度为1×105个/mL,分别用普通培养液(A组)及含0(B组)、1×10-9(C组)、1×10-8(D组)、1×10-7(E组)、1×10-6(F组)、1×10-5 mol/L(G组)地塞米松的成骨诱导培养液对ADSCs进行培养。MTT法检测细胞增殖情况;RT-PCR检测诱导细胞骨钙素(osteocalcin,OC)和核心结合因子α1(core binding factorα1,Cbfα1)的表达;测定ALP活性及矿化面积百分率;对矿化结节行茜素红染色。结果 ADSCs形态多为梭形、多角形,呈"漩涡状"排列;表面抗原分子CD44呈阳性,CD106呈阴性,成脂诱导后可观察到细胞内有脂滴形成,油红O染色呈阳性。MTT检测显示随地塞米松浓度升高,吸光度(A)值呈下降趋势;其中成骨诱导5、7 d时,D、E组A值比较差异有统计学意义(P<0.05)。RT-PCR检测示,成骨诱导7 d OC和Cbfα1 mRNA的表达分别在E组和D组达高峰;成骨诱导14 d ALP活性和矿化面积百分率均在D组达高峰,随后逐渐下降。D、E组间OC和Cbfα1 mRNA的表达量、ALP活性及矿化面积百分率比较差异均无统计学意义(P>0.05),与其余各组比较差异均有统计学意义(P<0.05)。成骨诱导14 d,G组细胞均死亡;茜素红染色除A、G组外均呈阳性。结论成骨培养液中地塞米松浓度为1×10-8 mol/L时,能在减少对细胞增殖抑制的同时,更有效地诱导ADSCs成骨分化。     

葛根素诱导脂肪干细胞成骨分化的实验研究

目的观察葛根素诱导卵巢切除后骨质疏松大鼠模型的脂肪干细胞(adipose-derived stem cells,ADSCs)成骨分化的能力。方法分离、培养、传代及鉴定去卵巢骨质疏松模型大鼠ADSCs;含葛根素培养基诱导去卵巢骨质疏松大鼠ADSCs成骨分化,并测定最大有效浓度。结果去卵巢骨质疏松大鼠ADSCs成骨分化能力与加入含葛根素培养基的时间和培养基中葛根素的浓度呈正向相关,浓度为12 mmol/L时呈现无毒剂量下促进成骨分化最显著作用。结论葛根素具有较强促进去卵巢骨质疏松大鼠ADSCs成骨分化的诱导能力。     

富血小板血浆诱导脂肪干细胞成骨作用的实验研究

目的探讨在体外培养中富血小板血浆（PRP）对脂肪干细胞的增殖及诱导成骨的影响。方法从Wistar大鼠自体动脉血中提取PRP，配制成条件培养液，并作用于培养状态的脂肪干细胞，MTT法检测细胞的增殖情况，Kaplow法染色检测细胞碱性磷酸酶表达情况，碱性磷酸酶活性检测，茜素红染色鉴定钙结节形成情况。结果脂肪干细胞经诱导培养后，PRP诱导组较对照组增殖明显（P〈0．01），碱性磷酸酶活性较对照组增高明显（P〈0．01），PRP诱导组碱性磷酸酶染色阳性，茜素红染色可见钙结节形成。结论体外培养时，PRP可促进脂肪干细胞的增殖并能诱导成骨分化，从而为骨组织工程提供一种新的方法。     

脂肪间充质干细胞的成骨诱导分化

目的研究脂肪间充质干细胞(MSCs）在特定培养条件下向成骨细胞分化，探讨其作为骨组织工程的种子细胞的可行性。方法取3周龄Lewis大鼠的腹股沟脂肪垫，消化法获得脂肪MSCs，用成骨诱导培养基诱导其向成骨细胞分化，组织化学染色、免疫细胞化学染色和Western blotting检测细胞分化的情况。结果从成体大鼠脂肪组织中培养出脂肪MSCs，能大量稳定增殖传代。在地塞米松、抗坏血酸、β-甘油磷酸钠的诱导下，脂肪MSCs的ALP活性增高，Von Kossa染色出现钙结节，OPN、BMP-2免疫细胞化学染色阳性．Western blotting检测到诱导后细胞OPN、BMP-2的表达，且随诱导时间延长表达增强。结论从脂肪组织中可获得具有多分化潜能的MSCs，并能在体外稳定增殖传代，经诱导后可分化为脂肪细胞和成骨细胞，有可能成为骨组织工程较理想的种子细胞之一。     

自体PRP促进人脂肪来源干细胞成骨分化的体外实验研究

目的 探讨自体PRP对体外培养人脂肪来源干细胞(adipose-derived stem cells,ADSCs)增殖及成骨分化的影响.方法 取自愿捐献吸脂术获取的脂肪组织进行分离培养ADSCs,倒置显微镜下观察细胞生长情况.将第3代ADSCs分别行成脂、成软骨定向诱导培养鉴定,并行CD29及CD44免疫荧光染色观察.取第3代ADSCs分别采用含10 mL/L PRP的成骨诱导培养基(PRP组)和不含PRP的成骨诱导培养基(对照组)进行培养,倒置显微镜观察细胞生长情况,培养后1、2、3、4、5 d采用MTT法检测细胞增殖活性;7、14、21、28 d行ALP活性检测,另取培养7、14 d的PRP组细胞行ALP染色观察;14 d时行PRP组茜素红染色检测钙结节形成情况.结果 倒置显微镜下第3代ADSCs多为梭形,倍增时间约35 h.成脂及成软骨诱导鉴定均为阳性,免疫荧光染色CD29和CD44呈阳性.MTT法示PRP组1、2、3、4、5 d的吸光度值分别为0.137±0.015、0.219±0.023、0.367±0.031、0.586±0.039、0.948±0.046,对照组分别为0.081±0.009、0.115±0.012、0.162±0.017、0.242±0.025、0.356±0.032,两组比较差异均有统计学意义(P＜0.01).成骨诱导7 d后,PRP组ALP染色阳性,细胞胞浆呈灰黑色,可见黑色沉淀:14 d后阳性细胞增多.ALP活性检测示PRP组7、14、21、28 d细胞活性值分别为23.96±2.05、41.26±3.38、38.12±3.03、35.89±2.24,对照组分别为17.83±1.62、26.64±2.37、23.85±1.99、20.78±1.81,两组比较差异均有统计学意义(P＜0.01).成骨诱导14 d后,茜索红染色示PRP组钙结节形成.结论 体外培养时,自体PRP可促进人ADSCs的增殖并诱导成骨分化,为骨组织工程提供一种新的种子细胞来源.     

不同声强低强度脉冲超声对SD大鼠骨髓间充质干细胞迁移的影响

目的探讨不同声强低强度脉冲超声(LIPUS)辐照对骨髓间充质干细胞(BMSCs)体外迁移的影响。方法将BMSCs分为空白对照组、30mW/cm~2组、60mW/cm~2组及90mW/cm~2组,对空白对照组仅行LIPUS假辐照操作,而对其余3组以相应声强进行辐照。以细胞划痕实验分析LIPUS对划痕愈合的促进作用,并通过MTT活性检测排除细胞增殖能力的干扰。采用transwell迁移实验评价各组BMSCs的迁移能力。通过FITC-鬼笔环肽染色检测F-肌动蛋白(Factin)表达结果 LIPUS辐照(空白对照组假辐照)后24h及48h,30mW/cm~2组、60mW/cm~2组、90mW/cm~2组及空白对照组间划痕面积差异均有统计学意义(F=26.559、106.110,P均0.001),且空白对照组划痕面积[辐照后24h:(0.93±0.26)mm~2,辐照后48h:(0.70±0.11)mm~2]最大,30mW/cm~2组[辐照后24h:(0.47±0.21)mm~2,辐照后48h:(0.19±0.10)mm~2]最小;而辐照后即刻各组间划痕面积差异无统计学意义(F=2.921,P=0.063)。LIPUS辐照(空白对照组假辐照)后即刻、24h及48h各组间吸光度差异均无统计学意义(F=1.616、0.720、1.408,P=0.196、0.544、0.378)。各组间穿过transwell小室上室的BMSCs细胞计数差异有统计学意义(F=43.145,P0.001),且30 mW/cm~2组细胞计数[(212.53±35.32)个]最大,空白对照组[(89.53±19.27)个]最小。F-actin染色显示,LIPUS辐照后BMSCs微丝增粗变长,数量增多。各组间相对荧光强度差异有统计学意义(F=64.350,P0.001),且30 mW/cm~2组相对荧光强度(125.43±17.43)最大,空白对照组(51.94±12.76)最小。结论 LIPUS可促进BMSCs体外迁移,声强为30mW/cm~2时促进效应最明显。     

兔脂肪干细胞的分离培养鉴定及成骨诱导分化研究

[目的]探讨在成骨诱导条件下兔脂肪干细胞的体外诱导分化情况：[方法]取3个月龄日本大耳白兔颈背部皮下脂肪，用Ⅰ型胶原酶消化获得细胞。Stro-1免疫细胞化学染色鉴定细胞性质；加入成骨诱导液后依次进行形态学、Ⅰ型胶原、碱性磷酸酶及钙盐沉积相关检测。[结果]（1）原代所获细胞Stro—1表达阳性？（2）在诱导条件下，Ⅰ型胶原、碱性磷酸酶及钙盐沉积均呈阳性表达。[结论]脂肪干细胞来源广、易获取、对机体创伤小，与骨髓间充质干细胞类似，经体外诱导后可实现成骨分化，为骨组织工程提供了一种新的种子细胞：     

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。     

低强度脉冲式超声促进骨愈合研究进展

低强度脉冲式超声能有效促进骨折和骨不连的愈合 ,机械效应和理化效应是其作用的基础。众多动物实验研究了超声机械信号变成化学信号的传导途径 ,尚未取得突破性进展 ;体外研究证实低强度脉冲式超声对成骨细胞、软骨细胞及骨膜细胞的效应 ,但还不能完全解释其在生物体内的作用机制。进一步探索作用机制 ,确定相应的工作参数 ,有助于指导临床应用 ,提高治疗效果     

Low intensity pulsed ultrasound stimulates osteogenic activity of human periosteal cells

The effect of low intensity pulsed ultrasound on human periosteal cells was investigated. Normal human periosteum was obtained to culture the periosteal cells. After characterization, cultures of periosteal cells at Days 2 and 4 were treated with ultrasound for 5, 10, and 20 minutes respectively. Assessments were done to assess total number of viable cells, cell proliferation, alkaline phosphatase activity, osteocalcin secretion, vascular endothelial growth factor expression, and calcium nodule formation. With the cells not treated with ultrasound as the control, the results showed that ultrasound did not affect the total number of viable cells. It stimulated cell proliferation at the early phase of cell culture. The activity of alkaline phosphatase was increased significantly in the culture at Day 4. A similar effect was seen with osteocalcin secretion and the responses were dose-dependent. The vascular endothelial growth factor secretion increased in Day 2 and Day 4 cultures with the dose-dependent effect. Formation of calcium nodules was significantly higher with ultrasound treatment. We think that low intensity pulsed ultrasound stimulated periosteal cell proliferation and differentiation toward osteogenic lineage. The dose-dependent effect on osteogenic activities may modify the existing treatment regimen. Ultrasound treatment should be started from the beginning of fracture healing.     

Effect of lactoferrin on osteogenic differentiation of human adipose stem cells

Purpose

Many in vitro studies of the analysis of the lactoferrin (LF) effect on cells have been reported. However, no study has yet investigated the effect of LF on osteogenic differentiation of human adipose-derived stem cells (hADSCs). The aim of this study was to evaluate the effect of LF on osteogenic differentiation of human adipose stem cells.

Methods

The hADSCs were cultured in an osteogenic medium with 0, 10, 50 and 100 μg/ml LF, respectively. hADSC proliferation was analysed by Cell Counting Kit-8 (CCK-8) assay, and cell osteogenic differentiation was evaluated by alkaline phosphatase (ALP) activity assay, von Kossa staining and real-time polymerase chain reaction (RT-PCR).

Results

Cell proliferation was significantly increased by LF in a dose-dependent manner from days 4 to 14. Cells cultured with 100 μg/ml LF presented a higher activity compared with the control. The deposition of calcium was increased after the addition of LF. The mRNA expression of type I collagen (COL-I), ALP, osteocalcin (OCN) and RUNX2 increased markedly as a result of LF treatment.

Conclusions

We have shown for the first time that LF could promote the proliferation and osteogenic differentiation of hADSCs, which could be a promising approach for enhancing osteogenic capacity of cell-based construction in bone tissue engineering.     

人脂肪组织来源干细胞体外增殖分化中端粒酶的表达

目的 探讨体外培养条件下人脂肪干细胞增殖和分化过程中端粒酶的表达水平,为其作为种子细胞的应用研究提供理论基础.方法 体外分离、培养人脂肪干细胞并传代,行流式细胞表面抗原分析,并用油红O染色及茜素红染色行成骨和成脂诱导分化的鉴定;采用TRAP法分别检测新鲜的不同时间培养的人脂肪干细胞和诱导分化为脂肪细胞的人脂肪干细胞的端粒酶活性.结果 脂肪干细胞具有向脂肪细胞、成骨细胞多向分化的能力,且表达干细胞相关表面标志物.新鲜分离和传代的脂肪干细胞,在体外培养12代内端粒酶活性呈阴性或低水平表达;一旦经过成脂诱导分化,细胞端粒酶活性表达上调,培养3～6 d后端粒酶活性开始出现逐渐降低.结论 用胶原酶消化法从脂肪抽吸术中得到的细胞主要是人脂肪干细胞;在体外培养增殖的过程中,人脂肪干细胞的端粒酶活性未见异常表达;成脂诱导分化早期人脂肪干细胞端粒酶活性增高,其后开始出现下降趋势.     

cAMP/PKA信号通路介导人脂肪干细胞成骨分化的体外试验

目的 研究环腺苷酸(cAMP)/蛋白激酶A(PKA)信号通路对脂肪干细胞(ADSCs)成骨分化的影响.方法 在成骨细胞培养基中加入cAMP/PKA信号通路的激动剂db-cAMP和抑制剂H-89,观察成骨细胞分化、PKA的活化及下游调节蛋白CREB的磷酸化和成骨基因表达的变化.结果 db-cAMP促进PKA的活化,上调CREB的磷酸化和相关基因表达的变化,促进ADSCs的成骨分化,同时以上作用可被PKA抑制剂H-89有效地阻断.结论 cAMP/PKA是介导人ADSCs成骨分化的重要信号通路.     

Effects of pulsed electromagnetic field frequencies on the osteogenic differentiation of human mesenchymal stem cells

The purpose of this study was to evaluate the effect of different frequencies of pulsed electromagnetic fields on the osteogenic differentiation of human mesenchymal stem cells. Third-generation human mesenchymal stem cells were irradiated with different frequencies of pulsed electromagnetic fields, including 5, 25, 50, 75, 100, and 150 Hz, with a field intensity of 1.1 mT, for 30 minutes per day for 21 days. Changes in human mesenchymal stem cell morphology were observed using phase contrast microscopy. Alkaline phosphatase activity and osteocalcin expression were also determined to evaluate human mesenchymal stem cell osteogenic differentiation.Different effects were observed on human mesenchymal stem cell osteoblast induction following exposure to different pulsed electromagnetic field frequencies. Levels of human mesenchymal stem cell differentiation increased when the pulsed electromagnetic field frequency was increased from 5 hz to 50 hz, but the effect was weaker when the pulsed electromagnetic field frequency was increased from 50 Hz to 150 hz. The most significant effect on human mesenchymal stem cell differentiation was observed at of 50 hz.The results of the current study show that pulsed electromagnetic field frequency is an important factor with regard to the induction of human mesenchymal stem cell differentiation. Furthermore, a pulsed electromagnetic field frequency of 50 Hz was the most effective at inducing human mesenchymal stem cell osteoblast differentiation in vitro.     

人脂肪干细胞结合微载体在生物反应器中向软骨细胞分化

[目的]探索在旋转生物反应器内,应用微载体技术快速扩增并向软骨分化人脂肪干细胞。[方法]将人脂肪干细胞结合Cytodex3微载体在旋转的生物反应器(RCSS)内进行动态培养,应用倒置显微镜和扫描电镜对微载体表面的脂肪干细胞进行动态观察,并对收获的脂肪干细胞进行Safran in-O、tolu id ine b lue染色等组织化学染色及Ⅱ型胶原的免疫化学染色分析。[结果]脂肪干细胞于24 h内贴附于Cytodex3微载体表面,细胞形态为短梭形,随时间的延长,贴附于微载体的细胞逐渐增多,到培养后期,细胞密度可达最初接种的19倍左右,在微载体上收获的细胞进行番红花O、阿利新蓝染色呈阳性,Ⅱ型胶原染色阳性,均强于对照组。[结论]利用微载体细胞培养技术可简便快速地在体外扩增脂肪干细胞,并成功实现向软骨细胞分化。     

Inhibition of osteogenic differentiation of human mesenchymal stem cells

Mesenchymal stem cells (hMSCs) have been shown to differentiate into osteoblasts that, in turn, are capable of forming tissues analogous to bone. The present study was designed to investigate the inhibition of osteogenesis by hMSCs. Bone marrow-derived hMSCs were treated with transforming growth factor beta-3 (TGFbeta3) at various doses during or after their differentiation into osteogenic cells. TGFbeta3 was encapsulated in poly(DL-lactic-co-glycolic acid) (PLGA) microspheres and released via controlled delivery in the osteogenic culture of hMSCs and hMSC-derived osteoblasts for up to 28 days. Controlled release of TGFbeta3 inhibited the osteogenic differentiation of hMSCs, as evidenced by significantly reduced alkaline phosphatase activity and staining, as well as decreased mineral deposition. After hMSCs had been differentiated into osteoblasts, controlled release of TGFbeta3 further inhibited not only alkaline phosphatase and mineral deposition but also osteocalcin expression. These findings demonstrate the potential for sustained modulation of the behavior of stem cells and/or stem cell-derived lineage-specific cells via controlled release of growth factor(s). The attenuation of osteogenic differentiation of MSCs may facilitate understanding not only the regulation and patterning of osteogenesis in development but also several pathological models such as osteopetrosis, craniosynostosis, and heart valve calcification.     

人骨髓间充质干细胞的生物学特性及成骨诱导分化的研究

[目的]探讨成人骨髓间充质干细胞分离、纯化、培养及鉴定的方法,观察其成骨分化过程中Runx2基因的动态表达以及生物学特性。[方法]取自人股骨近端骨髓标本,利用联合密度梯度离心和差异贴壁法分离骨髓间充质干细胞,体外扩增和传代培养,流式细胞仪检测细胞表面标记,诱导向成骨细胞分化,并采用RT-PCR和Western blot方法检测Runx2的动态表达。[结果]原代和传代细胞呈纺锤状外观,生长增殖能力良好,骨髓间充质干细胞的生长曲呈成"S"形,细胞表面标记物CD90阳性表达,CD34和CD45阴性表达。经定向诱导分化后,细胞分别呈现成骨细胞的表型特征,随着诱导时间的增加,Runx2的表达也明显增加,与对照组相比有统计学差异(P<0.05)。[结论]该方法能从人骨髓中高效分离和扩增MSCs,生物学性状稳定,具有成骨分化潜能,为骨组织工程提供理想的种子细胞,同时证实Runx2在成骨分化中起到重要的调控作用。