Hydroxyapatite coated with heaptocyte growth factor (HGF) stimulates human osteoblasts in vitro

We have studied in vitro the effect of a hydroxyapatite (HA) tricalcium phosphate material coated with hepatocyte growth factor (HA-HGF) on cell growth, collagen synthesis and secretion of metalloproteinases (MMPs) by human osteoblasts. Cell proliferation was stimulated when osteoblasts were incubated with untreated HA and was further increased after exposure to HA-HGF. The uptake of [3H]-proline was increased after treatment with HA. When osteoblasts were exposed to HA-HGF, collagen synthesis was increased with respect to HA. The secretion of MMPs in control cells was undetectable, but in HA and HA-HGF cells MMP 2 and MMP 9 were clearly synthesised. Our results suggest that HA can promote osteoblast activity and that HGF can further increase its bioactivity.     

剂量因素对羟基磷灰石/磷酸三钙成骨细胞相容性的影响

目的　检测不同剂量的羟基磷灰石 /磷酸三钙 (HA/ TCP)对兔成骨细胞增殖及碱性磷酸酶(AL P)活性的影响 ,明确材料的剂量因素在研究 HA/ TCP细胞相容性中的作用规律。方法　以兔成骨细胞为正常对照 ,细胞加入钛合金材料组为阴性对照 ,细胞加入聚氯乙烯材料组为阳性对照。选择三种材料剂量 ,以材料占细胞面积的比例表示 ,分别为 10 %、4 0 %和 70 %。将各组材料与兔成骨细胞复合培养 ,MTT法检测不同时间点、不同剂量材料作用下兔成骨细胞增殖的情况 ;偶氮偶联法检测不同时间点、不同剂量材料作用下兔成骨细胞表达 AL P的变化。结果　正常兔成骨细胞的生长呈现时间 -效应关系。与正常对照相比 ,10 % HA/ TCP不会对兔成骨细胞的生长产生影响 (P>0 .0 5 ) ;当 HA/ TCP剂量增大为 4 0 % ,细胞的生长速度明显变缓 (P<0 .0 5 ) ,细胞的生长仍呈现时间 -效应关系 ;70 %的 HA/ TCP使细胞生长趋于停滞 (P<0 .0 1)。 10 % HA/ TCP可造成细胞 AL P活性可逆性损伤 ,HA/ TCP浓度达 4 0 %时 ,AL P活性损伤至共培养 6天不可逆转。相对而言 ,惰性金属硬组织材料钛合金在检测三种剂量下均对细胞生长及细胞 AL P活性不会产生影响。结论　评价材料的细胞相容性应向材料接触剂量个体化、特异化的方向发展 ;除增殖指标之外 ,AL     

Parathyroid hormone 1 (1-34) acts on the scales and involves calcium metabolism in goldfish

The effect of fugu parathyroid hormone 1 (fugu PTH1) on osteoblasts and osteoclasts in teleosts was examined with an assay system using teleost scale and the following markers: alkaline phosphatase (ALP) for osteoblasts and tartrate-resistant acid phosphatase (TRAP) for osteoclasts. Synthetic fugu PTH1 (1-34) (100pg/ml-10ng/ml) significantly increased ALP activity at 6h of incubation. High-dose (10ng/ml) fugu PTH1 significantly increased ALP activity even after 18h of incubation. In the case of TRAP activity, fugu PTH1 did not change at 6h of incubation, but fugu PTH1 (100pg/ml-10ng/ml) significantly increased TRAP activity at 18h. Similar results were obtained for human PTH (1-34), but there was an even greater response with fugu PTH1 than with human PTH. In vitro, we demonstrated that both the receptor activator of the NF-κB ligand in osteoblasts and the receptor activator NF-κB mRNA expression in osteoclasts increased significantly by fugu PTH1 treatment. In an in vivo experiment, fugu PTH1 induced hypercalcemia resulted from the increase of both osteoblastic and osteoclastic activities in the scale as well as the decrease of scale calcium contents after fugu PTH1 injection. In addition, an in vitro experiment with intramuscular autotransplanted scale indicated that the ratio of multinucleated osteoclasts/mononucleated osteoclasts in PTH-treated scales was significantly higher than that in the control scales. Thus, we concluded that PTH acts on osteoblasts and osteoclasts in the scales and regulates calcium metabolism in goldfish.     

Effects of 50 Hz sinusoidal electromagnetic fields of different intensities on proliferation, differentiation and mineralization potentials of rat osteoblasts

Electromagnetic fields (EMFs) have been used clinically to slow down osteoporosis and promote fracture healing for many years. However, the underlying action mechanisms and optimal parameters of the EMF applications are unclear. In this study, we investigated the effects of treatment for different durations with 50 Hz sinusoidal electromagnetic fields (SEMFs) at different intensities on proliferation, differentiation and mineralization potentials of rat osteoblasts. Osteoblasts isolated from neonatal rats were treated with SEMFs (50 Hz at 0.9 mT–4.8 mT, 0.3 mT interval, 30 min/day up to 15 days). Compared to untreated control, SEMFs inhibited osteoblast proliferation (after 3 days' treatment) but increased alkaline phosphatase (ALP) activity (after treatment for 9 days) from 0.9 mT to 1.8 mT, declined from 1.8 mT until 3.0 mT, and then increased again from 3.0 mT to 3.6 mT and decreased once again from 3.6 mT to 4.8 mT. Numbers of colonies stained positive for ALP after 8 days and mineralized nodules stained by Alizarin red after 10 days showed the same bimodal tendency as with the ALP activity, with two peaks at 1.8 mT and 3.6 mT. SEMFs also bimodally increased Runx-2, Col1α2 and Bmp-2 mRNA expression levels in osteoblasts at 12, 24 and 96 h after exposure. The results indicated that while exposure to 50 Hz SEMFs inhibits the osteoblast proliferation, it significantly promotes differentiation and mineralization potentials of osteoblasts in an intensity-dependent manner with peak activity at 1.8 mT and 3.6 mT.     

Enhancing the osteoinductive properties of hydroxyapatite by the addition of human mesenchymal stem cells, and recombinant human osteogenic protein-1 (BMP-7) in vitro

Hydroxyapatite (HA) has been widely used as a bone graft substitute. In this study, we investigated whether the addition of osteogenic protein-1 (OP-1) further enhanced the weak osteoinductive properties of hydroxyapatite when loaded with human mesenchymal stem cells (h-MSCs). Over a 14 day period, cell proliferation in both groups was assessed qualitatively using SEM and quantitatively using alamar blue assay. Cell differentiation was also evaluated by measurement of ALP activity, which was expressed against total DNA. HA/MSC loaded with OP-1 demonstrated a statistically significant increase (p<0.001) in cell proliferation at all time points in comparison to unloaded samples. ALP activity per DNA was also significantly enhanced (p<0.001) in loaded samples when compared to unloaded controls. SEM demonstrated increased cellular attachment and proliferation into HA pores at all time points in the loaded samples. Our study suggests that the osteoinductive potential of HA can be improved in vitro by the combined incorporation of MSCs and OP-1.     

破骨细胞对IGF-1诱导成骨细胞骨同化的促进作用

目的 探讨破骨细胞(osteoclast, OC)存在时IGF-1对成骨细胞(osteoblast, OB)活性的影响。方法 体外培养MC3T3小鼠成骨细胞及RANKL诱导分化成熟的破骨细胞。以10ng/ mL的rhIGF-1直接干预单独或与破骨细胞共育的成骨细胞, 并设空白对照组,培养12h,检测成骨细胞的增殖、凋亡及碱性磷酸酶活性;培养8d后Von kossa钙化染色法观察矿化结节的形成。结果 成骨细胞、破骨细胞共培养时,rhIGF-1作用12h能够明显促进成骨细胞增殖(P<0.05),抑制成骨细胞的凋亡(P<0.05),使细胞内ALP活性升高(P<0.05),8d时钙化结节的个数及面积百分比升高(P<0.05);与单独培养的成骨细胞组有显著性差异。结论 破骨细胞可明显促进IGF-1所诱导的成骨细胞骨同化作用。     

甲状旁腺激素对大鼠成骨细胞增殖分化的影响

目的 探讨甲状旁腺激素(parathyroid hormone,PTH)对大鼠成骨细胞增殖及相关细胞因子的调节作用.方法 将传代的成骨细胞分为对照组、PTH持续给药组、PTH间歇给药组.持续给药组48 h中持续给药;PTH间歇给药组前6 h给予PTH,后42 h撤除;对照组予溶媒液.每48 h为一循环,持续作用8个循环,每个循环结束时,MTT法测定细胞增殖,检测碱性磷酸酶(ALP)活性,实时荧光定量PCR法(RT-PCR)测定胰岛素样生长因子-1(IGF-1)、骨形态发生蛋白-2(BMP-2)的表达水平.结果 间歇给药组细胞增殖在第7、8个循环时明显增加;而持续给药组在第5个循环时达到峰值,随后逐渐低于其他两组,在第7、8个循环时抑制作用明显.1～4个循环时3组间ALP活性差异无统计学意义,第5～8个循环ALP活性显著增加;持续给药组第6～8个循环对ALP活性有明显抑制作用.间歇给药组细胞IGF-1 mRNA的表达在第6个循环时达到高峰后有所下降,但始终明显高于其他两组;持续给药组前期IGF-1 mRNA表达水平较高,而后期则明显低于对照组.间歇给药组BMP-2 mRNA表达水平持续升高;持续给药组前3个循环表达水平较高,随给药时间的增长呈下降趋势.结论 间歇给予一定浓度的PTH可刺激成骨细胞的增殖与分化,后期作用大于前期.给药前期的ALP水平主要与IGF-1 mRNA表达水平相关,而后期则可能是通过BMP-2 mRNA表达的升高使ALP活性增强.     

脱氢表雄酮在体外对成骨细胞代谢和IL-1β的影响

目的探讨脱氢表雄酮（dehydroepiandrosterone，DHEA）对离体大鼠成骨细胞和IL-1β的影响。方法体外分离培养大鼠成骨细胞，取传一代细胞，分别给予10^-5mmoL／L、10^-7mmoL／L、10^-9mmol／LDHEA培养72h，以10^-8mmoL／L雌二醇（estradiol，E2）为阳性对照，另设空白对照组。碱性磷酸酶（alkaline phosphatase，ALP）染色鉴定成骨细胞，MTT法检测成骨细胞的增殖能力，PNPP法测定ALP活性。ELISA法测定不同浓度DHEA培养液中IL-1β的水平。结果不同浓度DHEA组成骨细胞增殖能力和ALP的活性均有上升，其中以10^-7mmoL／LDHEA组最显著（P〈0．01），其作用和E2相似（P〉0．05）；10^-9mmoL／LDHEA组单位细胞数的ALP活性高于空白对照组（P〈0．05）。不同浓度的DHEA组IL-1β呈下降趋势，成骨细胞增殖能力及ALP活性和IL-1β成负相关。结论DHEA在体外促进大鼠成骨细胞生长和增殖，提高ALP活性，其作用可能和抑制IL-1β有关。     

Effects of basic fibroblast growth factor on biological characteristics of osteoblasts

Objective: To elucidate the effects of exogenous basic fibroblast growth factor ( bFGF ) on biological characteristics of rat osteoblasts cultured in vitro. Methods: The osteoblasts isolated from a Sprague-Dawley rat and cultured in vitro were treated with different concentrations of bFGF ( 5-50 ng/ml) respectively. At 24 hours after treatment, the proliferating cell nuclear antigen was measured with immunocytochemistry, alkaline phosphatase (ALP) activity was determined and the expression of transforming growth factor beta 1 ( TGF-β1 )was detected to observe the effects of bFGF on growth and differentiation of osteoblasts. Resu/ts: bFGF ( 5-50 ng/ml ) could obviously promote the growth of osteoblasts. The intracellular expression of TGF-β1 mRNA increased significantly, but the intracellular ALP content decreased. Conclusions: bFGF can obviously stimulate the proliferation of osteoblasts and promote the synthesis of TGF-β1, but cannot promote the differentiation of osteoblasts.     

转化生长因子-β1基因转染鼠成骨细胞的研究

目的　研究转化生长因子 - β1 (TGF- β1 )基因转染鼠成骨细胞对其生物学特性的影响。方法　将TGF- β1 基因导入成骨细胞 ,通过原位杂交检测和成骨细胞培养上清液 TGF- β1 活性测定 (水貂肺上皮细胞生长抑制试验 ) ,了解转染细胞 TGF- β1 的表达。检测基因转染及转染细胞上清对成骨细胞增殖和碱性磷酸酶 (AL P)活性的影响 ,观察 TGF- β1 基因转染成骨细胞生物学活性的变化。结果　原位杂交检测基因转染成骨细胞可明显表达TGF- β1 。上清液 TGF- β1 活性检测结果显示 1∶ 1、1∶ 2、1∶ 4复合培养基对 Mv1抑制率分别为 16 .3%、2 2 .7%和2 8.2 % ,上清中 TGF- β1 含量越高 ,活化后对 Mv1抑制作用越明显。 TGF- β1 基因转染对成骨细胞生物学活性无明显影响 ,而转染细胞上清活化后可促进成骨细胞增殖 ,抑制 AL P活性。结论　 TGF- β1 基因转染鼠成骨细胞可显著促进 TGF- β1 表达 ,转染细胞生物学特性保持稳定 ,为骨缺损基因治疗的体内研究奠定了基础     

Role of N-cadherin and protein kinase C in osteoblast gene activation induced by the S252W fibroblast growth factor receptor 2 mutation in Apert craniosynostosis.

Apert (Ap) syndrome is characterized by premature cranial suture ossification caused by fibroblast growth factor receptor 2 (FGFR-2) mutations. We studied the role of cadherins and signaling events in the phenotypic alterations induced by the Ap FGFR-2 S252W mutation in mutant immortalized fetal human calvaria osteoblasts. The FGFR-2 mutation caused increased expression of the osteoblast markers alkaline phosphatase (ALP), type 1 collagen (COLIA1), and osteocalcin (OC) in long-term culture. The mutation also increased cell-cell aggregation, which was suppressed by specific neutralizing anti-N- and anti-E-cadherin antibodies. Mutant osteoblasts showed increased N- and E-cadherin, but not N-cell adhesion molecule (N-CAM) messenger RNA (mRNA) and protein levels. This was confirmed in vivo by the abundant immunoreactive N- and E-cadherins in preosteoblasts in the Ap suture whereas N-CAM and alpha- and beta-catenins were unaffected. Neutralizing anti-N-cadherin antibody or N-cadherin antisense (AS) oligonucleotides but not anti-E-cadherin antibody or AS reduced ALP activity as well as ALP, COLIA1, and OC mRNA overexpression in mutant osteoblasts. Analysis of signal transduction revealed increased phospholipase Cgamma (PLCgamma) and protein kinase Calpha (PKCalpha) phosphorylation and increased PKC activity in mutant cells in basal conditions. Inhibition of PKC by calphostin C or the PKCalpha-specific inhibitor G?6976 suppressed the increased N-cadherin mRNA and protein levels as well as the overexpression of ALP, COLIA1, and OC mRNA in mutant cells. Thus, N-cadherin plays a role in the activation of osteoblast differentiation marker genes in mutant osteoblasts and PKCalpha signaling appears to be involved in the increased N-cadherin and osteoblast gene expression induced by the S252W FGFR-2 mutation in human osteoblasts.     

流体切应力下SIVA-1凋亡诱导因子促成骨细胞增殖分化的双向调节作用

目的探讨流体切应力（fluid shear stress,FSS）对KM小鼠成骨细胞增殖分化及相关细胞凋亡诱导因子（SIVA-1）的调节作用。方法将传至3代成骨细胞分为应力刺激组（试验组）和非应力刺激组（对照组）。5个试验组分别给予1.2PaFSS作用0.25,0.5,1,2,4h;对照组为0h。MTT法测定细胞增殖,检测碱性磷酸酶（ALP）活性,半定量RT-PCR测定凋亡诱导因子SIVA-1的表达水平。结果FSS促增殖作用在短期（0.25,0.5h）明显,且细胞生长曲线前移;但在1,2,4h却有明显抑制增殖作用。FSS同样增加了ALP活性,尤其在应力作用0.5h时显著（ALP含量为2.4320±0.205金氏单位/100ml,相对对照达158%）（P〈0.05）;而应力作用1,2,4h后减低了ALP的表达。应力初期SIVA-1mRNA表达量明显下降,尤其在FSS作用0.5h后SIVA-1/GAPDH相对表达量为0.099±0.002,相对对照明显下调了71.3%（P〈0.01）,此效应在作用1h后减退,SIVA-1mRNA表达开始升高,4h后升高明显。结论1.2PaFSS在短时间刺激下可刺激成骨细胞增殖分化,尤其在0.5h后效应明显。早期促细胞增殖和ALP水平升高主要与SIVA-1mRNA表达下调有关,而后期抑制作用可能与SIVA-1mRNA表达升高有关。     

二苯乙烯苷调控miR-34a/SIRT1对骨质疏松大鼠的作用及机制研究

目的 探讨二苯乙烯苷(tetrahydroxy stilbene glycoside,TSG)调控微小RNA-34a(miR-34a)/沉默信息调节因子1(SIRT1)对骨质疏松症(osteoporosis,OP)大鼠的作用及机制.方法 将60只SD雌性大鼠随机分为假手术组、模型组、TSG组(80 mg/kg)、miR...     

铁饱和乳铁蛋白对大鼠成骨细胞增殖与分化的影响

目的 探讨铁饱和乳铁蛋白对体外培养的大鼠成骨细胞增殖和分化的影响.方法 用酶消化法分离大鼠颅盖骨成骨细胞进行原代培养;乳铁蛋白螯合Fe~(2+)获得铁饱和乳铁蛋白;将其稀释到不同浓度作用于成骨细胞,四唑盐比色法(MTT)测定细胞增殖;碱性磷酸酶法(ALP)测定细胞碱性磷酸酶活性.结果 随着时间的增加,各浓度组均可促进成骨细胞增殖及增强碱性磷酸酶活性.其中100 μg/mL浓度组在72 h时细胞增殖数目最大、碱性磷酸酶活性最高,较对照组有统计学意义(P＜0.01).结论 铁饱和乳铁蛋白能促进大鼠成骨细胞的增殖和分化.     

Effects of androgens on subpopulations of the human osteosarcoma cell line SaOS2

Previously, we showed that androgens stimulate murine and human osteoblast-like cell proliferation and differentiation by mechanisms involving increased responses to mitogenic growth factors (GF) and increased GF production. To explain this dual action of androgens on primary osteoblastic cell populations we advanced the hypothesis that androgens exert differential effects on osteoblastic subpopulations. We subcloned a human osteosarcoma cell line (SaOS2) into subpopulations expressing high (HAS) and low (LAS) levels of alkaline phosphatase (ALP). The obtained subclones differed significantly in their ALP production and expressed a high and low ALP phenotype, respectively, for the entire experimental period. Dihydrotestosterone (DHT) increased specific ALP activity and type-I procollagen peptide secretion in both HAS and LAS. DHT pretreatment enhanced the mitogenic action of basic fibroblast growth factor (bFGF) and insulinlike growth factor 2 (IGF2) only in HAS. The enhanced mitogenic effect of IGF2 in HAS after DHT pretreatment was associated with increased IGF2-receptor mRNA levels. Therefore, we conclude that androgens exert their osteoanabolic action (1) by stimulating differentiated functions of osteoblastic cells with a high and a low ALP phenotype, and (2) via increased growth factor receptor expression and thereby enhancing mitogenic growth factor responses only in HAS. This paper is dedicated to the occasion of Prof. Dr. R. Ziegler's 60th birthday     

Stimulation by bone sialoprotein of calcification in osteoblast-like MC3T3-E1 cells

Bone sialoprotein (BSP) containing an Arg-Gly-Asp cell-binding sequence was purified from bovine bone 4 M guanidine-HCl extract after HCl demineralization by a series of chromatographic procedures. When this protein was coated on culture dishes in the presence of type I collagen, it increased both DNA content and alkaline phosphatase (ALP) activity in osteoblast-like MC3T3-E1 cells, and stimulated calcification in the cells, whereas fibronectin, another cell-binding protein, showed a marked increase in the DNA content but had little effect on the ALP activity. These findings suggest that BSP is mitogenic for preosteoblasts and differentiating the cells into osteoblasts, thereby stimulating bone calcification     

骨组织工程细胞支架复合珊瑚羟基磷灰石生物相容性研究

目的研究复合珊瑚羟基磷灰石(CCHA)与成骨细胞的生物相容性。方法将成骨细胞分别和复合骨形态发生蛋白的珊瑚羟基磷灰石(CCHA)、单纯珊瑚羟基磷灰石(CHA)混合培养,检测细胞增殖指数和碱性磷酸酶(ALP)活性。结果CCHA对成骨细胞的ALP活性有明显的促进作用,CHA对ALP活性没有影响。二者对细胞增殖指数均无影响。结论CCHA具有良好的生物相容性和骨诱导作用。     

Expression of preosteoblast markers and Cbfa-1 and Osterix gene transcripts in stromal tumour cells of giant cell tumour of bone

In giant cell tumour of bone (GCT), mononuclear stromal cells, which represent the neoplastic component of this lesion, regulate the formation of multinucleated osteoclast-like giant cells which are the characteristic hallmark of this tumour. However, the origin of stromal tumour cells has not yet been clearly defined. In this study, we evaluated several osteoblast markers including collagen type I, bone sialoprotein (BSP), osteonectin and osteocalcin in GCT using immunohistochemical techniques. Amongst the 13 GCT specimens and 7 GCT stromal cell (GCTSC) cultures studied, majority of the GCTSC synthesized type I collagen, BSP and osteonectin proteins but did not produce the differentiated osteoblast marker, osteocalcin. We further examined the regulation of several important osteogenic genes such as Cbfa-1, osterix and osteocalcin, and regulation of ALP activity in GCTSC in culture by bone morphogenetic protein 2 (BMP-2). Real-time PCR analysis indicated that Cbfa-1, osterix and osteocalcin mRNA were present in primary cultures of GCTSC. The addition of BMP-2 upregulated Cbfa-1 and osterix gene expression within 12 h and the enhancement was still observed at 24 h. ALP activity was minimal in untreated GCTSC in cultures. The number of ALP-positive GCTSC was significantly increased following treatment with BMP-2 or combinations with beta-glycerophosphate and ascorbic acid. In contrast, BMP enhancement of osterix mRNA level and ALP activity was also seen in SaOS2 osteoblast-like cells, but not in the primary culture of normal human skin fibroblasts. In summary, our data suggest that GCT stromal tumour cells may have an osteoblastic lineage and retain the ability to differentiate into osteoblasts.