骨髓间充质干细胞向软骨细胞的分化

背景：以骨髓间充质干细胞构建组织工程气管尚缺乏理想的特异性表面标志物,对其鉴定主要依赖细胞形态学、细胞表型及诱导分化的功能进行分析。 目的：体外分离培养、鉴定兔骨髓间充质干细胞,观察在特定条件下向气管软骨细胞分化的潜能。 方法：无菌环境取兔骨髓,经全骨髓贴壁筛选法分离培养细胞至第2代,流式细胞术鉴定第1、第2代细胞表面抗原CD44、CD45的表达。无菌环境取气管,经酶消化法分离培养气管软骨细胞,甲苯胺蓝染色鉴定软骨细胞蛋白聚糖的合成。在使用转化生长因子β1的基础上,将骨髓间充质干细胞与气管软骨细胞通过Transwell小室非接触式共培养,倒置显微镜观察细胞形态,甲苯胺蓝染色鉴定蛋白聚糖的合成,荧光实时定量PCR鉴定Ⅱ型胶原和蛋白聚糖 mRNA的表达。 结果与结论：分离、培养的细胞呈长梭形、不规则形聚集生长,传代后细胞生长速度明显增快,呈鱼群状聚集生长。第1代有96.97%的细胞表达CD44、13.72%的细胞表达CD45,第2代有99.11%的细胞表达CD44、8.54%的细胞表达CD45。气管软骨细胞甲苯胺蓝染色阳性。在诱导后,骨髓间充质干细胞形态逐渐由长梭形变为三角形或不规则形,表达软骨细胞特异性Ⅱ型胶原和蛋白聚糖 mRNA基因,甲苯胺蓝染色示阳性。结果表明全骨髓贴壁筛选法可成功分离培养骨髓间充质干细胞,第2代纯度较高,且在特定诱导条件下具有分化为气管软骨细胞的潜能。     

A specific drug targeting system based on polyhydroxyalkanoate granule binding protein PhaP fused with targeted cell ligands

Polyhydroxyalkanoates (PHA) is a family of intracellular biopolyesters produced by many bacteria. PHA granule binding protein PhaP is able to bind to hydrophobic polymers via strong hydrophobic interaction. A receptor-mediated drug delivery system was developed in this study based on PhaP. The system consists of PHA nanoparticles, PhaP and polypeptide or protein ligands fused to PhaP. The PHA nanoparticles were used to package mostly hydrophobic drugs; PhaP fused with ligands produced by over-expression of their corresponding genes in Pichia pastoris, or E. coli was able to attach to hydrophobic PHA nanoparticle. At the end, the ligands were able to pull the PhaP-PHA nanoparticles to the targeted cells with receptors recognized by the ligands. It was found in this study that the receptor-mediated drug specific delivery system ligand-PhaP-PHA nanoparticles were taken up by macrophages, hepatocellular carcinoma cell BEL7402 in vitro and liver, hepatocellular carcinoma cells in vivo, respectively, when the ligands were mannosylated human alpha1-acid glycoprotein (hAGP) and human epidermal growth factor (hEGF), respectively, which were able to bind to receptors of macrophages or hepatocellular carcinoma cells. The nanoparticle system was clearly visible in the targeted cells and organs (liver or tumor) under fluorescence microscopy when rhodamine B isothiocyanate (RBITC) was used as a delivery model drug due to the specific targeting effect created by specific ligand and receptor binding. The delivery system of hEGF-PhaP-nanoparticles carrying RBITC was found to be endocytosed by the tumor cells in tumorous model mice. Thus, the ligand-PhaP-PHA specific drug delivery system was proven effective both in vitro and in vivo.     

基底膜基质/壳聚糖诱导骨髓间充质干细胞成软骨分化

背景：课题组前期研究发现基底膜基质能够定向诱导骨髓间充质干细胞向软骨方向分化,但其力学性能与实际应用有较大差距,还需要进一步研究。 目的：制备兼具适宜力学性能和优异生物相容性的壳聚糖/基底膜基质水凝胶支架用于软骨修复。 方法：以京尼平为交联剂,将壳聚糖溶液与基底膜基质按2︰1,1︰1,1︰3比例混合制成水凝胶,接种大鼠骨髓间充质干细胞,培养14 d。经材料力学测试、细胞增殖、活细胞染色、酶联免疫吸附测试以及阿尔新蓝染色等方法评价材料诱导细胞成软骨分化能力。 结果与结论：在基底膜基质内添加壳聚糖后,材料力学性能从0.48 kPa上升到1.78 kPa。标志性蛋白分泌结果显示,纯壳聚糖组早期诱导成软骨活性高于其他组,但后期诱导能力减弱,而含基底膜基质各组在后期能够保持较好的诱导活性,其中壳聚糖/基底膜基质=1︰1组材料具有一定的力学强度,且Ⅱ型胶原和Ⅹ型胶原的表达量在14 d较其他组高。结果表明实验制备的壳聚糖/基底膜基质水凝胶具有良好的力学性能,并能够促进骨髓间充质干细胞向软骨方向分化,可用于软骨组织工程研究。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

不同生长因子诱导骨髓间充质干细胞向软骨细胞表型转化的机制

背景：关节软骨损伤后,自身修复能力十分有限,以往医学手段无法对其进行再生修复,利用干细胞治疗软骨损伤彻底扭转了这一局面。 目的：探讨不同生长因子诱导骨髓间充质干细胞向软骨细胞表型的转化机制。 方法：取第5代大鼠骨髓间充质干细胞,利用不同的生长因子及生长因子组合对大鼠骨髓间充质干细胞进行诱导,分别为TGF-β1组、TGF-β1+IGF-1组、BMP-2+IGF-1组、TGF-β1+BMP-2组、TGF-β1+IGF-1+BMP-2组、空白对照组。诱导后21 d进行阿尔新蓝染色和茜素红染色,RT-PCR检测Ⅱ型胶原mRNA表达。 结果与结论：阿新蓝染色观察可见细胞胞浆与间质存在异染情况,蛋白多糖呈绿色表达,经茜素红染色未见橘红色钙结节。初步推断,骨髓间充质干细胞已分化形成软骨细胞,不表达骨细胞表型。空白对照组Ⅱ型胶原mRNA表达呈阴性。与TGF-β1组比较,BMP-2+IGF-1组Ⅱ型胶原mRNA表达显著偏低,TGF-β1+BMP-2组和TGF-β1+IGF-1+BMP-2组Ⅱ型胶原mRNA表达显著偏高(P < 0.05);且TGF-β1+IGF-1+BMP-2组Ⅱ型胶原mRNA表达显著高于其他各组(P < 0.05)。结果表明,转化生长因子β1具备单独诱导骨髓间充质干细胞向软骨分化的能力,采用胰岛素样生长因子1、骨形态发生蛋白2、转化生长因子β1在诱导骨髓间充质干细胞向软骨分化时具有协同作用,可以发挥出最大的诱导软骨分化效应。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

Chondrogenic differentiation of adult mesenchymal stem cells and embryonic cells in collagen scaffolds

Many cell types and cellular microenvironments have been explored for articular cartilage tissue engineering. We compared the potential of bone marrow-derived mesenchymal stem cells (MSCs) and P19 embryonic carcinoma cells (ECCs), a pluripotent derivative of embryonic stem cells (ESCs), for cartilage histogenesis in porous collagen scaffolds in vitro. We found that while both MSCs and ECCs express α-smooth muscle actin (α-SMA), only MSCs exhibit condensation and contraction necessary for cartilage histogenesis. Furthermore, histology confirmed that only MSCs exhibited sulfated glycosaminoglycans and collagen type II formation after 14 days in culture. We conclude that MSCs appear to be superior over ECCs for cartilage regeneration under particular culture conditions. The α-SMA-expressing ECCs may not have contracted due to the absence of actin unit polymerization or the absence of myosin molecules. Our observations may explain the absence of a contractile scar in fetal wound healing.     

脱细胞随机肌腱支架促进骨髓间充质干细胞骨向分化

目的:探究随机肌腱细胞外基质(ECM)支架对骨髓间充质干细胞(BMSCs)活力和分化的影响。方法:从Sprague-Dawley大鼠股骨和胫骨中提取BMSCs,体外培养,观察细胞形态,并利用流式细胞术鉴定细胞干性。采用1%Triton X-100和DNase/RNase混合液对鼠尾肌腱进行脱细胞处理,利用HE染色和DNA含量测定考察肌腱组织中细胞核残余情况。制备胶原纤维随机排列的肌腱ECM支架,培养BMSCs,以孔板中生长的细胞为对照组,利用Live/Dead染色和CCK8法考察细胞的活力和形态;利用RT-qPCR检测肌腱标志物I型胶原蛋白(Col I)、肌腱特异转录因子scleraxis(SCX)及成骨标志物碱性磷酸酶(ALP)和Runt相关转录因子2(RUNX2)的表达水平。结果:HE染色结果显示,经过脱细胞处理后肌腱组织内无细胞残余,且DNA含量从(481. 7±15. 8)μg/g显著性降至(31. 0±3. 8)μg/g(P<0. 05),脱细胞处理成功。7 d时,种植在支架上的BMSCs的活力较对照组显著增强(P<0. 05);14 d时,种植在支架上的BMSC...     

Chondrogenic differentiation of human mesenchymal stem cells on photoreactive polymer-modified surfaces

Human mesenchymal stem cells (MSCs) were cultured on polystyrene surfaces modified with photoreactive azidophenyl-derivatives of three different chargeable polymers, poly(acrylic acid) (PAAc), polyallylamine (PAAm), and poly(ethylene glycol) (PEG). The MSCs adhered and spread both on a PAAm-modified surface and on PAAc-modified and polystyrene (control) surfaces. However, the cells adhered more easily to the PAAm-modified surface. The MSCs did not attach to the PEG-modified surface and aggregated to form pellets immediately after cell seeding. The cells proliferated on the PAAc-, PAAm-modified and control surfaces with culture time, formed a monolayer, and aggregated to form pellets. The cells in the pellets that formed on the PAAm- and PEG-modified surfaces after 2 weeks culture had a round morphology and the extracellular matrices were positively stained by safranin O and toluidine blue, while those that formed on the PAAc-modified and control surfaces had a spindle, fibroblast-like morphology and were not positively stained by safranin O and toluidine blue. The pellets that formed on the PAAm- and PEG-modified surfaces contained significantly higher levels of sulfated glycosaminoglycans than did those that formed on the PAAc-modified and control surfaces. Type II collagen and cartilage proteoglycan were immunohistologically detected in the pellets that formed on PAAm- and PEG-modified surfaces, but not those that formed on the PAAc-modified and control surfaces. The MSCs cultured on the PAAm- and PEG-modified surfaces expressed a high level of cartilaginous genes encoding type II collagen and aggrecan, while the MSCs cultured on the PAAc-modified and control surfaces did not express these genes. These results suggest that the PAAm-modified surface supported cell adhesion and proliferation and also promoted chondrogenic differentiation of the MSCs. The PAAc-modified and polystyrene surfaces supported cell adhesion and proliferation, but not chondrogenic differentiation. The PEG-modified surfaces did not support cell adhesion, but did promote chondrogenic differentiation. The adhesion, proliferation, and differentiation of the MSCs could be controlled by surface chemistry.     

Chondrogenic differentiation of human mesenchymal stem cells in three-dimensional alginate gels

We characterized the temporal changes in chondrogenic genes and developed a staging scheme for in vitro chondrogenic differentiation of human mesenchymal stem cells (hMSCs) in three-dimensional (3D) alginate gels. A time-dependent accumulation of glycosaminoglycans, aggrecan, and type II collagen was observed in chondrogenic but not in basal constructs over 24 days. qRT-PCR demonstrated a largely characteristic temporal pattern of chondrogenic markers and provided a basis for staging the cellular phenotype into four stages. Stage I (days 0-6) was defined by collagen types I and VI, Sox 4, and BMP-2 showing peak expression levels. In stage II (days 6-12), gene expression for cartilage oligomeric matrix protein, HAPLN1, collagen type XI, and Sox 9 reached peak levels, while gene expression of matrilin 3, Ihh, Homeobox 7, chondroadherin, and WNT 11 peaked at stage III (days 12-18). Finally, cells in stage IV (days 18-24) attained peak levels of aggrecan; collagen IX, II, and X; osteocalcin; fibromodulin; PTHrP; and alkaline phosphatase. Gene profiles at stages III and IV were analogous to those in juvenile articular and adult nucleus pulposus chondrocytes. Gene ontology analyses also demonstrated a specific expression pattern of several putative novel marker genes. These data provide comprehensive insights on chondrogenesis of hMSCs in 3D gels. The derivation of this staging scheme may aid in defining maximally responsive time points for mechanobiological modulation of constructs to produce optimally engineered tissues.     

miR-195对人骨髓间充质干细胞成骨分化的影响

BACKGROUND:Previous studies have found that the expression level of miR-195 in differentiated human bone marrow mesenchymal stem cells (hBMMSCs) is significantly higher than that in undifferentiated hBMMSCs. However, miR-195 effect during this differentiation process and possible mechanism remain unclear. OBJECTIVE:To explore the effect of miR-195 on osteogenic differentiation of hBMMSCs and possible mechanism. METHODS:hBMMSCs were isolated and cultured in vitro. Alkaline phosphatase activity, Runx2, osteopontin and SMAD7 protein expression and miR-195 expression level during osteogenic differentiation of hBMMSCs were determined by alkaline phosphatase kit, western blot and real-time PCR, respectively. miR-195-downexpressed hBMMSCs were constructed by lipofection transfection, and were used to investigate the effect of miR-195 was on osteogenic differentiation of hBMMSCs. Dual luciferase reporter assay was used to identify whether the 3’UTR of SMAD7 mRNA was a binding target of miR-195. In addition, we transfected hBMMSCs with SMAD7 cDNA (pcDNA-SMAD7), and investigated the effect of SMAD7 on osteogenic differentiation of hBMMSCs. RESULTS AND CONCLUSION:The isolated and cultured hBMMSCs had good osteogenic differentiation ability in vitro. Expression level of miR-195 was increased with the increasing of induction time, and the expression level of SMAD7 was reversed. miR-195 promoted osteogenic differentiation of hBMMSCs. Luciferase assay confirmed that miR-195 targeted SMAD7 directly, and overexpression of SMAD7 inhibited the osteogenic differentiation of hBMMSCs. Taken together, miR-195 promotes osteogenic differentiation of hBMMSCs by targeting SMAD7.     

Chondrogenic differentiation of human mesenchymal stem cells on oriented nanofibrous scaffolds: engineering the superficial zone of articular cartilage

Cell differentiation, adhesion, and orientation are known to influence the functionality of both natural and engineered tissues, such as articular cartilage. Several attempts have been devised to regulate these important cellular behaviors, including application of inexpensive but efficient electrospinning that can produce patterned extracellular matrix (ECM) features. Electrospun and oriented polycaprolactone (PCL) scaffolds (500 or 3000 nm fiber diameter) were created, and human mesenchymal stem cells (hMSCs) were cultured on these scaffolds. Cell viability, morphology, and orientation on the fibrous scaffolds were quantitatively determined as a function of time. While the fiber-guided initial cell orientation was maintained even after 5 weeks, cells cultured in the chondrogenic media proliferated and differentiated into the chondrogenic lineage, suggesting that cell orientation is controlled by the physical cues and minimally influenced by the soluble factors. Based on assessment by the chondrogenic markers, use of the nanofibrous scaffold (500 nm) appears to enhance the chondrogenic differentiation. These findings indicate that hMSCs seeded on a controllable PCL scaffold may lead to an alternate methodology to mimic the cell and ECM organization that is found, for example, in the superficial zone of articular cartilage.     

尿酸抑制人骨髓间充质干细胞的成脂分化

背景：研究表明一些药物可影响骨髓间充质干细胞的成骨、成脂诱导分化。 目的：观察尿酸对人骨髓间充质干细胞成脂分化的影响。 方法：全骨髓培养法体外分离培养人骨髓间充质干细胞,在成脂诱导条件下,分别加入0(对照组),0.1,0.2,0.4,0.8 mmol/L浓度尿酸,诱导14,21 d时行油红O染色,倒置显微镜下计数成脂细胞数量。 结果与结论：成脂诱导14 d后,含不同浓度尿酸的诱导组成脂细胞数量较对照组明显减少(P < 0.05),且随着尿酸浓度的增加,抑制成脂细胞生成的效果更为明显(P < 0.05);成脂诱导21 d后,尿酸对骨髓间充质干细胞成脂诱导分化的抑制作用较诱导14 d时更加明显(P < 0.05),同样随着尿酸浓度的增加,抑制作用更加明显(P < 0.05)。说明在体外尿酸能够抑制人骨髓间充质干细胞的成脂分化,并且存在一定的浓度依赖性和时间依赖性。     

壳聚糖支架上骨髓间充质干细胞的浓度及黏附生长

背景：组织工程的研究重点是利用少量的细胞经体外培养、扩增后, 在一定环境下附着在三维多孔支架上并良好生长为后期的组织器官重建修复做好基础。 目的：对不同浓度兔骨髓间充质干细胞复合至壳聚糖支架用于组织工程再生修复进行评价。 方法：取5×10⁵脱乙酰度为95%的壳聚糖粉末通过冷冻干燥法制备壳聚糖支架,取1×10⁶,1×10⁷,1×10⁸,1×10⁹ L^-1细胞体积各100 μL复合至壳聚糖支架后1,3,5,7,9 d以光镜,扫描电镜,MTT法观察骨髓间充质干细胞的生长与分裂增殖情况。 结果与结论：壳聚糖海绵状多孔支架为5 mm×5 mm×3 mm,孔径190~380 μm,平均孔径290 μm,孔相通性较好,空隙率为(84.00±4.62)%。细胞/支架共培养72 h后各浓度细胞组均可渗入壳聚糖支架多孔结构内黏附生长。1×10⁷,1×10⁸,1× 10⁹ L^-1浓度细胞组在支架上成蔟生长,部分细胞与支架融合。结果提示,1×10⁷,1×10⁸L^-1组细胞更利于骨髓间充质干细胞在壳聚糖支架的黏附生长,用于组织再生修复。     

Chondrogenic differentiation of human mesenchymal stem cells in collagen type I hydrogels

The chondrogenic differentiation of bone marrow-derived human mesenchymal stem cells (MSCs) in a collagen type I hydrogel, which is in clinical use for matrix-based autologous chondrocyte transplantation (ACT), was investigated. Collagen hydrogels with 2.5 x 10(5) MSCs/mL were fabricated and cultured for 3 weeks in a serum-free, defined, chondrogenic differentiation medium containing 10 ng/mL TGF-beta1 or 100 ng/mL BMP-2. Histochemistry revealed morphologically distinct, chondrocyte-like cells, surrounded by a sulfated proteoglycan-rich extracellular matrix in the TGF-beta1 and BMP-2 treated group, with more elongated cells seen in the BMP-2 treated group. Immunohistochemistry detected collagen type II (Col II) in the TGF-beta1 and BMP-2 treated group. Collagen type X (Col X) staining was positive in the TGF-beta1 but only very weak in the BMP-2 treated group. RT-PCR analyses revealed a specific chondrogenic differentiation with the expression of the cartilage specific marker genes Col II, Col X, and aggrecan (AGN) in the TGF-beta1 and the BMP-2 treated group, with earlier expression of these marker genes in the TGF-beta1 treated group. Interestingly, MSC-gels cultured in DMEM with 10% FBS (control) indicated few isolated chondrocyte-like cells but no expression of Col II or Col X could be detected. The results show, that MSCs cultured in a collagen type I hydrogel are able to undergo a distinct chondrogenic differentiation pathway, similar to that described for MSCs cultured in high-density pellet cultures. These findings are valuable in terms of ex vivo predifferentiation or in situ differentiation of MSCs in collagen hydrogels for articular cartilage repair.     

骨形态发生蛋白2和7共转染骨髓间充质干细胞的成骨分化

背景：骨形态发生蛋白最主要的作用是诱导骨形成,但因提取困难、代谢速度快、难以准确控制其使用浓度、价格昂贵等限制了其在体外和体内相关研究中的应用。 目的：构建含特异细胞生长因子基因骨形态发生蛋白2,7的腺病毒载体,观察骨形态发生蛋白2和骨形态发生蛋白7基因共转染对兔骨髓间充质干细胞成骨分化的促进作用。 方法：将全骨髓贴壁法分离得到兔骨髓间充质干细胞传至第3代,分为5组,空白组和常规诱导组分别以常规培养基和成骨诱导分化培养基培养;骨形态发生蛋白2, 7腺病毒转染组：分别单独以骨形态发生蛋白2、骨形态发生蛋白7腺病毒进行转染;联合转染组：以2种骨形态发生蛋白腺病毒联合转染。 结果与结论：转染第7天,联合转染组成骨相关基因Runx-2、Osx、Ⅰ型胶原和碱性磷酸酶mRNA表达均较其他各组增高(P < 0.05);骨形态发生蛋白2,7腺病毒转染组上述指标较空白组和常规诱导组增高(P < 0.05)。转染第14天,联合转染组4个指标均较其他各组明显增高(P < 0.05);同时,4个指标表达均高于第7天(P < 0.05)。病毒转染后第7天,联合转染组Ⅰ型胶原和骨钙素蛋白表达均较其他组明显增高(P < 0.05)。提示对骨髓间充质干细胞进行骨形态发生蛋白2腺病毒和骨形态发生蛋白7腺病毒共转染后,较单基因转染和成骨诱导液诱导更能促进成骨相关基因和蛋白的表达。     

Chondrogenic differentiation of bone marrow-derived mesenchymal stem cells induced by acellular cartilage sheets

Acellular cartilage sheets (ACSs) have been used as scaffolds for engineering cartilage with mature chondrocytes. In this study we investigated whether ACSs possess a chondrogenic induction activity that may benefit cartilage engineering with multipotent stem cells. Bone marrow-derived mesenchymal stem cells (BMSCs) isolated from newborn pigs were expanded in vitro and seeded on ACSs that were then stacked layer-by-layer to form BMSC-ACS constructs. Cells seeded on polyglycolic acid/polylactic acid (PGA/PLA) scaffolds served as a control. After 4 weeks of culture with or without additional chondrogenic factors, constructs were subcutaneously implanted into nude mice for another 4 weeks. Cartilage-like tissues were formed after 4 weeks of culture. However, formation of cartilage with a typical lacunar structure was only observed in induced groups. RT-PCR showed that aggrecan, COMP, type II collagen and Sox9 were expressed in all groups except the non-induced BMSC-PGA/PLA group. At 4 weeks post-implantation, cartilage formation was achieved in the induced BMSC-ACS group and partial cartilage formation was achieved in the non-induced BMSC-ACS group, confirmed by safranin O staining, toluidine blue staining and type II collagen immunostaining. In addition, enzyme-linked immunosorbent assay demonstrated the presence of transforming growth factor-β1, insulin-like growth factor-1 and bone morphogenic protein-2 in ACSs. These results indicate that ACSs possess a chondrogenic induction activity that promotes BMSC differentiation.     

腺病毒介导的人骨形态发生蛋白2基因转染骨髓间充质干细胞

背景：骨髓间充质干细胞作为骨、软骨创伤缺损及退变修复的种子细胞越来越受到关注。 目的：分析人骨形态发生蛋白2基因转染对白色封闭群大鼠(SD大鼠)骨髓间充质干细胞的影响。 方法：分离纯化SD大鼠骨髓间充质干细胞并体外扩增,通过腺病毒载体介导人骨形态发生蛋白2基因转染骨髓间充质干细胞,分别通过荧光显微镜观察荧光表达情况及蛋白质水平来测定转染后人骨形态发生蛋白2的表达,碱性磷酸酶定量测定鉴定成骨活性及MTT法评估人骨形态发生蛋白2转染对骨髓间充质干细胞的影响。 结果与结论：从SD大鼠骨髓提取物中分离培养的细胞形态为梭形,呈铺路石状、漩涡状生长,经流式细胞仪检测及多项分化能力鉴定符合骨髓间充质干细胞的特征;经转染人骨形态发生蛋白2基因后,骨髓间充质干细胞表达人骨形态发生蛋白2、碱性磷酸酶;MTT法检测转染人骨形态发生蛋白2基因后,骨髓间充质干细胞增殖能力明显增强(P < 0.05)。说明人骨形态发生蛋白2基因转染骨髓间充质干细胞后可以持续、高效表达人骨形态发生蛋白2和碱性磷酸酶,在体外明显促进骨髓间充质干细胞的增殖。