补骨脂素对大鼠成骨细胞增殖与分化的影响

为探讨补骨脂素体外对大鼠成骨细胞增殖与分化的影响,用改良的组织块法分离培养新生大鼠颅骨成骨细胞,补骨脂素以不同浓度加入细胞培养体系,作用不同时间后,用MTT法检测成骨细胞的增殖情况;用对硝基苯二钠基质动力学法测定细胞内碱性磷酸酶的活性,用改良的Lowry法测蛋白含量。补骨脂素浓度在1μmol/L 24 h,5~20μmol/L浓度范围内48 h,1、10、20μmol/L浓度范围内72 h促进成骨细胞增殖,在10~15μmol/L范围内48 h及72 h提高成骨细胞内碱性磷酸酶的活性。补骨脂素体外能促进成骨细胞的增殖与分化。     

山萘酚对大鼠成骨细胞增殖与分化的影响

为探讨山萘酚体外对大鼠成骨细胞增殖与分化的影响及中药菟丝子补肾壮骨作用的物质基础,用改良的组织块法分离培养新生大鼠颅骨成骨细胞,山萘酚以不同浓度加入细胞培养体系,作用不同时问后,用MTF法检测成骨细胞的增殖情况;用对硝基苯二钠基质动力学法测定细胞内碱性磷酸酶的活性,用改良的Lowry法测蛋白含量。山萘酚在浓度1×10^-5mol／L24h,1×10^-5～1×10^-7mol／L浓度范围内48h促进成骨细胞增殖,在浓度1×10^-9moL／L48h及72h提高成骨细胞内碱性磷酸酶的活性。山萘酚体外能促进大鼠成骨细胞的增殖与分化,山萘酚可能是菟丝子补肾壮骨作用的活性成份之一。     

甲氧补骨脂素对大鼠成骨细胞生物活性影响的实验研究

为探讨甲氧补骨脂素对体外培养新生大鼠颅骨成骨细胞增殖与分化作用的影响,用改良的组织块培养法分离培养新生大鼠颅骨成骨细胞,在成骨细胞体系中以不同浓度加入甲氧补骨脂素,MTT法检测加药后不同时间细胞的增殖情况;用对硝基苯二钠基质动力学法(PNPP)测定细胞内碱性磷酸酶的活性,用改良的Lowry法测蛋白含量;用放射免疫法测定细胞内骨钙素含量。结果显示:与对照组相比,甲氧补骨脂素组在24 h和36 h时促进体外大鼠成骨细胞增殖的作用更明显;在24、48 h和72 h时均能提高成骨细胞碱性磷酸酶活性(ALP)和骨钙素(BGP)的分泌。甲氧补骨脂素对体外培养的大鼠成骨细胞的增殖与分化均有明显的促进作用。     

异补骨脂素加锌对大鼠成骨细胞增殖与分化的影响

为探讨异补骨脂素加锌对体外培养新生大鼠颅骨成骨细胞增殖与分化作用的影响,用改良的组织块培养法分离培养新生大鼠颅骨成骨细胞,在成骨细胞体系中以不同浓度加入异补骨脂素与锌,MTT法检测加药后不同时间成骨细胞的增殖情况;用对硝基苯二钠基质动力学法(PNPP)测定细胞内碱性磷酸酶的活性,用改良的Lowry法测蛋白含量.结果显示:异补骨脂素加锌较单纯应用异补骨脂素或硫酸锌在24和48 h时促体外大鼠成骨细胞增殖的作用更加明显;在48和72 h时能促进成骨细胞碱性磷酸酶活性(ALP),其中ALP的测定在72h的活性更为显著.与单纯应用异补骨脂素或者锌相比,异补骨脂素与锌联合应用能够协同增效,对体外培养的成骨细胞的增殖与分化作用更加显著.     

五味子乙素对大鼠成骨细胞增殖分化的影响

目的:探讨五味子乙素体外对大鼠成骨细胞增殖与分化的影响。方法:用改良的组织块法分离培养新生大鼠颅骨成骨细胞,五味子乙素以不同浓度加入细胞培养体系,作用不同时间后,用MTT法检测成骨细胞的增殖情况;用对硝基苯二钠基质动力学法(PNPP)测定细胞内碱性磷酸酶的活性,用改良的Lowry法测蛋白含量。结果:五味子乙素在0.75×10-4 mol/L 24 h,48 h及72 h,及0.75×10-5mol/L 24 h促进成骨细胞的增殖,在0.75×10-6mol/L24 h提高成骨细胞内碱性磷酸酶的活性。结论:五味子乙素体外能促进成骨细胞的增殖与分化。     

甲状旁腺激素相关蛋白对心肌成纤维细胞增殖的影响

目的：观察外源性甲状旁腺激素相关蛋白（1—40）（PTHrp（1-40））对原代培养新生Wistar鼠心肌成纤维细胞（CFs）增殖及胶原合成的影响。方法：分离、培养Wistar乳鼠心肌成纤维细胞,加入不同浓度的PTHrp（1-40）共培养,用四氮唑盐比色法（MTT法）和^3H—TdR掺入法检测细胞增殖;^3H—Proline掺入法测定胶原合成。结果随着一定浓度PTHrp（1-40）的升高,CFs MTT法A490值及^3H—TdR的掺入量,^3H-脯氨酸掺入率呈明显的递减趋势。结论：PTHrp在一定程度上可抑制成纤维细胞增殖及细胞外基质的沉积。     

补骨脂素加锌对大鼠成骨细胞增殖与分化影响的实验研究

为探讨补骨脂素加锌对体外培养新生大鼠颅骨成骨细胞增殖、分化作用的影响及其量效关系,用改良的组织块培养法分离培养新生大鼠颅骨成骨细胞,在成骨细胞体系中以不同浓度加入补骨脂素与锌,MTT法检测加药后不同时间成骨细胞的增殖情况;用对硝基苯二钠基质动力学法(PNPP)测定细胞内碱性磷酸酶的活性;用放射免疫法(RIA)测定细胞外骨钙素(BGP)的含量,用改良的Lowry法测蛋白含量。补骨脂素加锌较单独应用补骨脂素或硫酸锌在48 h和72 h时促体外大鼠成骨细胞增殖的作用更加明显;在24、48 h和72 h时能提高成骨细胞碱性磷酸酶(ALP)活性,其中在48 h时的效果更为显著;在24 h和72 h时能提高细胞外液中的骨钙素含量;补骨脂素浓度为1×10-9mol/L和锌浓度为1×10-5mol/L两者联合用药较为合适。与单独应用补骨脂素或者锌相比,补骨脂素与锌联合应用能够协同增效,对体外培养的大鼠成骨细胞的增殖与分化作用更加显著。     

雌激素对成骨细胞增殖及IGF-2表达的调控作用

目的 探讨雌激素对大鼠成骨细胞功能的影响及胰岛素样生长因子2（insulin-like growth factor 2,IGF-2）表达的调控机理。方法应用1×10^-10mol／L、1×10^-8mol／L、1×10^-6mol／L浓度的雌二醇（estradiol,172）分别作用原代培养的新生大鼠颅盖骨成骨细胞24h;采用MTT法和对硝基酚磷酸盐法检测成骨细胞增殖能力和细胞中碱性磷酸酶（ALP）活性;应用实时定量PCR和Western印迹杂交分析成骨细胞中IGF-2的mRNA和蛋白质的表达规律。结果1×10^-6mol／L浓度的磁使大鼠成骨细胞增殖能力和ALP活性分别增加了67％和55％,使IGF-2的mRNA与蛋白质的表达水平分别增加了90％和140％,差异有统计学意义（P〈0．05）。结论雌激素对成骨细胞中IGF-2基因的表达具有正性调控作用。成骨细胞中IGF-2的高表达可能与雌激素调节成骨细胞增殖和分泌功能相关。     

乙酰胆碱对培养的人垂体腺瘤细胞增殖的影响

目的：了解乙酰胆碱（acetylcholine,Ach)对人垂体腺瘤细胞增殖的影响。方法：将Ach作用于体外培养的人垂体腺瘤细胞,测定MTT反应A值和^3H-TdR参入量及用流式细胞仪测定细胞周期。结果：10^-7-10^-5mol/LAch可剂量依赖性地使MTT反应A值和^3H-TdR参入量降低,使垂体腺瘤G1期细胞比例增加（P＜0．01）,并可被阿托品阻断。结论：Ach在体外能明显抑制培养的人垂体腺瘤细胞的增殖,这种作用是通过Ach受体来实现的。     

佛手柑内酯对大鼠成骨细胞增殖与分化的影响

为研究佛手柑内酯对大鼠成骨细胞增殖、分化的影响。原代培养新生大鼠颅骨细胞,利用MTT法、微量酶标法、酶联免疫吸附法(ELISA)、q PCR等方法分别测定不同浓度佛手柑内酯对大鼠成骨细胞增殖,碱性磷酸酶(ALP),骨钙素(BGP),Ⅰ型胶原mRNA(CollagenⅠmRNA)表达的影响。结果显示,与对照组相比,佛手柑内酯作用于细胞24、48、72 h均对成骨细胞的增殖有促进作用(P0.05);作用48、72 h均能促进ALP、BGP、CollagenⅠmRNA表达(P0.05)。表明佛手柑内酯可促进大鼠成骨细胞的增殖和分化,为防治骨质疏松症的新药研究提供理论依据。     

高浓度地塞米松通过下调LMP-1表达抑制大鼠成骨细胞的分化

为探讨地塞米松（dexamethasone,DEX)抑制成骨细胞分化的机制,观察了不同浓度DEX对体外培养大鼠成骨细胞的碱性磷酸酶活性,骨钙素（osteocalcin,OC)合成,I型胶原蛋白表达的影响。并用RT-PCR方法检测了成骨细胞中LIM矿化蛋白1mRNA的表达量,结果显示：低浓度（10^-9mol/L）的DEX能增强碱性磷酸酶的活性、OC的分泌和I型胶原蛋白的表达;而高浓度（10^-7mol/L)的DEX对它们则起抑制作用,并下调成骨细胞正调节因子LMP-1mRNA的表达,上述结果表明,低浓度的DEX促进成骨细胞的分化;高浓度的DEX则抑制成骨细胞的分化,其抑制作用可能是通过下调LMP-1mRNA的表达而实现的。     

心室成纤维细胞条件培养液促进成纤维细胞胶原合成和增殖

采用心室成纤维细胞条件培养液培养心室成纤维细胞,通过测定[^3H]－脯氨酸（[^3H]－proline）的掺入率来了解心室成纤维细胞总胶原合成速率,通过测定[^3H]－胸腺嘧啶核苷（[^3H]－TdR）的掺入率以及c-fos基因的表达丰度来了解心室成纤维细胞的增殖速率。结果显示：心室成纤维细胞条件培养液（FCGM）能增加细胞自身的[^3H]－proline的掺入率和[^3H]－TdR的掺入率,并具有剂量依赖性;FCGM也能促进细胞自身c-fos基因的表达,刺激后1h达高峰。ETA受体拮抗剂BQ123能部分阻断FCGM增加成纤维细胞胶原合成的增殖作用,而AT1受体拮抗剂CV11974和α肾上腺素受体拮抗剂regitin无此效果。结果提示：心室成纤维细胞具有自分泌功能,能分泌内皮素等生物活性物质,促进成纤维细胞胶原的合成和增殖。     

Antiosteoporotic activity of phenolic compounds from Curculigo orchioides

Six phenolic compounds isolated from Curculigo orchioides, including 2,6-dimethoxy benzoic acid (1), curculigoside A (2), curculigoside B (3), curculigine A (4), curculigine D (5) and 3,3′,5,5′-tetramethoxy-7,9′:7′,9-diepoxylignan-4,4′-di-O-β-d-glucopyranoside (6), together with the ethanol extract of Curculigo orchioides were evaluated for their activity on osteoblasts in neonatal rat calvaria cultures and multinucleated osteoclasts derived from rat marrow cells so as to characterize the antiosteoporotic components of this plant and explore the relationship of chemical structure with antiosteoporotic activity. The proliferation of osteoblast was assayed by MTT methods. The activity of ALP (alkaline phosphatase) and TRAP (tartrate-resistant acid phosphatase) was measured by p-nitrophenyl sodium phosphate assay. The TRAP stain was used to identify osteoclast in morphology. The resorption pit area on the bone slices formed by osteoclast was measured by computer image processing. The ethanol extract exhibited stimulatory effect on both the osteoblast proliferation and the ALP activity. Six compounds all increased the osteoblast proliferation, and compounds (1), (2) and (4) also slightly increased the osteoblastic ALP activity. Compounds (1), (2), (3), (6) and the ethanol extract decreased area of bone resorption pit, osteoclastic formation and TRAP activity. These results indicated that phenolic compounds are antiosteoporotic chemical constituents from Curculigo orchioides, and their activities are related with chemical structures.     

锌对铅染毒新生大鼠成骨细胞增殖分化的影响

目的:探讨铅锌联合染毒对乳鼠颅骨成骨细胞增殖分化的影响。方法:分离并培养原代成骨细胞,加入不同浓度铅、锌培养48h,检测其对成骨细胞增殖的作用;用碱性磷酸酶试剂盒检测ALP活力。结果:在染铅48h后,当铅浓度≥10μmol/L时,细胞增殖功能下降(P<0.05);加锌干预48h后,铅+锌组细胞增殖功能均高于各自单独染铅组,其中铅(1μmol/L、10μmol/L)+锌(50μmol/L)组、铅(10)+锌(100)组与对照组间的差异具有统计学意义(P<0.05)。铅干预48h后,100μmol/L铅组的ALP活力显著下(P<0.05),给予锌干预的铅锌联合染毒组,各组ALP活力均有增加,其中铅(1μmol/L、10μmol/L)+锌(50μmol/L)组ALP活力均高于对照组,而铅(100μmol/L)+锌(50μmol/L)组ALP活力低于对照组,差异均有统计学意义(P<0.05)。结论:铅对成骨细胞有毒性作用,影响其增殖和分化功能;50μmol/L锌在一定程度上可以拮抗铅对成骨细胞增殖和分化功能的损伤,且对ALP活力的作用更显著,为铅中毒骨病的防治提供一定的科学依据。     

Effects of selective prostaglandin EP2 and EP4 receptor agonists on bone resorption and formation in fetal rat organ cultures

Prostaglandin E2 (PGE2) can stimulate bone resorption and formation through receptors which activate adenylyl cyclase. We examined the effects of selective EP2 and EP4 agonists (EP2A and EP4A) on the release of previously incorporated 45Ca from fetal rat long bones and the incorporation of [3H]-proline or [3H]-thymidine (TdR) in fetal rat calvaria to assess the relative effects of these selective agonists on bone formation and resorption. Only EP4A was effective in increasing 45Ca release. Both agonists increased [3H]-TdR incorporation and [3H]-proline incorporation into calvariae, particularly in the presence of cortisol.     

Age-related changes in bone formation,osteoblastic cell proliferation,and differentiation during postnatal osteogenesis in human calvaria

We have determined the age-related changes in the growth characteristics and expression of the osteoblast phenotype in human calvaria osteoblastic cells in relation with histologic indices of bone formation during postnatal calvaria osteogenesis. Histomorphometric analysis of normal calvaria samples obtained from 36 children, aged 3 to 18 months, showed an age-related decrease in the extent of bone surface covered with osteoblasts and newly synthesized collagen, demonstrating a progressive decline in bone formation during postnatal calvaria osteogenesis. Immunohistochemical analysis showed expression of type I collagen, bone sialoprotein, and osteonectin in the matrix and osteoblasts, with no apparent age-related change during postnatal calvaria osteogenesis. Cells isolated from human calvaria displayed characteristics of the osteoblast phenotype including alkaline phosphatase (ALP) activity, osteocalcin (OC) production, expression of bone matrix proteins, and responsiveness to calciotropic hormones. The growth of human calvaria osteoblastic cells was high at 3 months of age and decreased with age, as assessed by (³H)-thymidine incorporation into DNA. Thus, the age-related decrease in bone formation is associated with a decline in osteoblastic cell proliferation during human calvaria osteogenesis. In contrast, ALP activity and OC production increased with age in basal conditions and in response to 1,25(OH)₂, vitamin D₃, suggesting a reciprocal relationship between cell growth and expression of phenotypic markers during human postnatal osteogenesis. Finally, we found that human calvaria osteoblastic cells isolated from young individuals with high bone formation activity in vivo and high growth potential in vitro had the ability to form calcified nodular bone-like structures in vitro in the presence of ascorbic acid and β-glycerophosphate, providing a new model to study human osteogenesis in vitro. J. Cell. Biochem. 64:128–139. © 1997 Wiley-Liss, Inc.     

Genistein abolishes nucleoside uptake by cardiac fibroblasts

Genistein, a soy isoflavone, is reported to exert significant beneficial action in several human disorders, which has generated immense interest in the mechanisms underlying its effects on diverse cellular processes. It has anti-proliferative action on many cell types, an effect generally attributed to tyrosine kinase inhibition. In this study, genistein was found to cause total inhibition of [³H]-thymidine incorporation into DNA and a modest reduction in [³H]-proline incorporation into protein in primary cultures of cardiac fibroblasts. The decrease in [³H]-thymidine incorporation was not associated with a decrease in cell proliferation but correlated exactly with low intracellular levels of [³H]-thymidine. Genistein dramatically reduced [³H]-thymidine but not [³H]-proline uptake by these cells in which the equilibrative nucleoside transporter may be the major route of nucleoside uptake. The effect was irreversible and was demonstrable in pulmonary fibroblasts as well. The findings suggest that nucleoside uptake mechanisms may be a novel target of genistein action in cardiac fibroblasts and point to serious limitations in using genistein to assess the role of tyrosine kinase in cell proliferation by the standard technique of [³H]-thymidine incorporation.     

Icariin is more potent than genistein in promoting osteoblast differentiation and mineralization in vitro

There has been a strong interest in searching for natural therapies for osteoporosis. Genistein, an isoflavone abundant in soy, and icariin, a prenylated flavonol glycoside isolated from Epimedium Herb, have both been identified to exert beneficial effects in preventing postmenopausal bone loss. However, the relative potency in osteogenesis between the individual phytoestrogen flavonoids remains unknown. The present study compared ability of genistein and icariin in enhancing differentiation and mineralization of cultured rat calvarial osteoblasts in vitro. Dose-dependent studies in osteoblast differentiation measuring alkaline phosphatase (ALP) activity revealed optimal concentrations of genistein and icarrin for stimulating osteogenesis to be both at 10(-5) M. Time course studies comparing the two compounds both at 10(-5) M demonstrated that icariin treatment always produced higher ALP activity, more and larger areas of CFU-F(ALP) colonies and mineralized nodules, more osteocalcin secretion, and calcium deposition, and a higher level of mRNA expression of osteogenesis-related genes COL1α2, BMP-2, OSX, and RUNX-2. However, they inhibited the proliferation of osteoblasts to a similar degree. In conclusion, although future in vivo studies are required to investigate whether icariin is more efficient in improving bone mass and/or preventing bone loss, our in vitro studies have demonstrated that icariin has a stronger osteogenic activity than genistein. In addition, while the prenyl group on C-8 of icariin could be the active group that takes part in osteoblastic differentiation and explains its greater potency in osteogenesis, mechanisms of action, and reasons for the relative potency of icariin versus genistein need to be further studied.