蛇床子素对大鼠成骨细胞增殖分化的影响

蛇床子素对大鼠成骨细胞增殖分化的影响@王建华$河北医科大学中西医结合研究所!石家庄050017 @宋冬梅$河北医科大学中西医结合研究所!石家庄050017 @刘楠$河北医科大学中西医结合研究所!石家庄050017 @李恩$河北医科大学中西医结合研究所!石家庄050017~~~~~~~~     

高压氧对体外培养的成骨细胞增殖和分化的影响

为探讨高压氧对成骨细胞增殖和成骨分化的影响,把来源于牙槽骨的成骨细胞接种在24孔培养皿中,每孔2 500个细胞,4个治疗组分别接受不同条件的高压氧治疗,分别是2.4ATA 90 min,2.4ATA 30 min,1.5ATA 90 min和1.5ATA30 min,每天一次,共10天.对照组进行常规的细胞培养.分别在高压氧治疗前和高压氧治疗后的1、2、3、4、6、8、10天,采用WST-1分析试剂进行成骨细胞的增殖分析.使用乳酸脱氢酶(LDH)毒性分析法检测高压氧对成骨细胞的毒性影响.另将细胞接种于96孔培养皿中,每孔10 000个细胞,正常培养3天后,改用成骨化培养基,24h后,两个治疗组分别接受2.4ATA 90 min和1.5ATA 90 min的高压氧治疗,每天一次共19次.采用钙沉积分析法、碱性磷酸酶(ALP)活性分析和Von Kossa染色进行成骨分析.同样的方法观察高压空气对细胞增殖和分化的影响.结果显示,在10%小牛血清培养基条件下,高压氧刺激了成骨细胞的增殖,而在使用2%小牛血清培养基时,并末观察到高压氧对细胞增殖的促进作用.高压氧治疗前后细胞外乳酸脱氢酶含量没有发生改变,提示了高压氧未对成骨细胞造成毒性影响.另一方面,高压氧增加了骨结节的形成,同时钙沉积增加,碱性磷酸酶的活力也显著增强,表明了高压氧促进了成骨细胞的成骨分化.     

染料木黄酮对去势大鼠骨骼矿化的影响

目的: 研究染料木黄酮对去势大鼠骨骼矿化的影响.方法: 雌性Wistar大鼠47只随机分为假手术组,去势对照组、去势 雌激素组(己烯雌酚20 μg.kg bw-1.d-1)、去势 染料木黄酮组(剂量分别为25、50、100 mg.kg bw-1.d-1).饲养三个月后处死,测定骨密度、骨矿化相关参数、骨钙、磷、锌、镁、锰、血清甲状旁腺激素、降钙素和雌激素含量.结果: 大鼠去势后,股骨骨密度降低,平均类骨质宽度增大,骨矿化延迟时间和类骨质成熟时间延长,骨中钙、磷、锌、镁和血清雌激素含量降低,与假手术组相比均有显著性差异(P＜0.05);补充染料木黄酮后,股骨骨密度有改善的趋势,平均类骨质宽度变窄,骨矿化延迟时间和类骨质成熟时间缩短,骨中钙、磷、镁含量升高.结论: 染料木黄酮通过促进类骨质矿化,减少骨中钙、磷、镁丢失,预防骨质疏松的发生.     

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。     

染料木黄酮改善γ射线损伤小鼠抗氧化功能的作用

用137Csγ射线照射雄性昆明小鼠,观察饲料中补充染料木黄酮(Genistein,Gen)对抗氧化功能的保护作用,探讨其抗辐射作用的机制。结果表明,Gen可以提高辐射小鼠脾和胸腺组织总抗氧化能力(T-AOC)、降低血清、肝脏和胸腺组织丙二醛(MDA)水平;显著提高辐射小鼠抗氧化功能。     

补骨脂素对乳鼠颅骨成骨细胞分化成熟的影响

骨质疏松症是一种全身性骨骼疾病,其特点是骨量低、骨微结构恶化、骨脆性增加、易骨折。为了改善骨质疏松,需要寻找合成代谢和口服药物的副作用最小的替代药物。补骨脂素是从中草药中提取的香豆素衍生物。然而,补骨脂素在成骨细胞功能中的作用及其分子机制尚不清楚。本研究发现,补骨脂素通过上调成骨细胞特异性标志基因(包括icollagen,骨钙素和骨唾液蛋白)的表达,增强碱性磷酸酶的活性,以剂量依赖的方式促进小鼠原代成骨细胞的成骨分化。本研究同时证明补骨脂素能上调BMP2和BMP4基因的表达,提高磷酸化smad1/5/8蛋白水平,激活BMP报告基因(12xbe-oc-luc)的活性以及增强BMP信号直接靶基因osx的表达。BMP2和BMP4基因的缺失消除了补骨脂素对成骨细胞标志基因col1、alp、oc和bsp表达的促进作用。结果表明,补骨脂素通过激活BMP信号促进成骨细胞分化,提示补骨脂素可能是治疗骨质疏松等骨丢失相关疾病的一种潜在的合成代谢剂。     

女贞子对大鼠成骨细胞增殖与分化的影响

为探讨女贞子Fructus Ligustri Lucidi体外对大鼠成骨样细胞UMR-106增殖与分化的影响,女贞子水提物(LWE)以不同浓度加入细胞培养体系,用Am-Blue细胞增殖与活性检测试剂检测成骨细胞的增殖情况;以检测细胞内碱性磷酸酶的活性为指标考察成骨细胞的分化情况。结果表明,LWE在100μg/mL作用48 h能促进细胞的增殖,作用24~48 h能明显促进细胞的分化。在转染了5×ERE-Luc荧光素酶报告基因质粒的乳腺癌细胞MCF-7中检测到LWE能促进雌激素受体反应元件调控下的荧光素酶的表达;且LWE促UMR-106细胞分化的作用能被雌激素受体拮抗剂ICI18270所抑制,表明女贞子很可能是通过雌激素受体信号途径对成骨细胞的分化起作用的。     

三碘甲腺原氨酸对大鼠成骨细胞增殖的影响

目的:探讨三碘甲腺原氨酸(T3)对大鼠成骨细胞增殖的影响.方法:采用骨组织块法原代分离培养新生SD大鼠颅骨成骨细胞,然后配置含不同浓度(10-7mol/L、10-8mol/L、10-9mol/L )T3的培养基,与大鼠成骨细胞共培养4d,采用噻唑蓝(MTT)法检测细胞增殖能力,采用细胞化学染色法测定成骨细胞ALP活性.结果:T3可促进大鼠成骨细胞增殖,并呈剂量依赖性;随T3浓度的增高,成骨细胞表达ALP活性增强(P＜0.05).结论:10-7mol/L～10-9mol/L浓度的T3可通过刺激成骨细胞的增殖,对预防和治疗骨质疏松发挥一定作用.     

三碘甲腺原氨酸对大鼠成骨细胞增殖的影响

目的:探讨三碘甲腺原氨酸(T3)对大鼠成骨细胞增殖的影响。方法:采用骨组织块法原代分离培养新生SD大鼠颅骨成骨细胞,然后配置含不同浓度(10-7mol/L、10-8mol/L、10-9mol/L)T3的培养基,与大鼠成骨细胞共培养4d,采用噻唑蓝(MTT)法检测细胞增殖能力,采用细胞化学染色法测定成骨细胞ALP活性。结果:T3可促进大鼠成骨细胞增殖,并呈剂量依赖性;随T3浓度的增高,成骨细胞表达ALP活性增强(P<0.05)。结论:10-7mol/L～10-9mol/L浓度的T3可通过刺激成骨细胞的增殖,对预防和治疗骨质疏松发挥一定作用。     

重组Osx腺病毒载体的构建及其调控成骨细胞增殖与分化的作用

构建表达成骨相关转录因子Osx的腺病毒,观察Osx对原代培养的小鼠成骨细胞增殖与分化的调控作用。将Osx编码基因克隆入腺病毒载体pAdEasy中,经293A包装后得到重组腺病毒,感染原代培养的小鼠颅骨细胞,茜素红染色观察矿化程度,实时定量RT-PCR检测成骨相关标志基因的转录水平,流式细胞检测细胞周期的改变。结果发现,①得到的病毒滴度为2×109PFU/ml,最佳感染复数为50;②表达Osx并不能够促进成骨细胞的矿化;③定量RT-PCR表明表达Osx 1d、3d、6d后成骨分化标志骨钙素、骨涎蛋白、Ⅰ型胶原蛋白的表达量明显上调(p<0.01);④流式细胞仪的结果表明Osx能够促进成骨细胞的增殖(p<0.01)。通过腺病毒在原代培养的成骨细胞中表达Osx能够促进成骨细胞的增殖,并对其分化具有一定的调控作用,为Osx在各种骨损伤的基因治疗应用方面提供了基础。     

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.     

miR-542-3p suppresses osteoblast cell proliferation and differentiation,targets BMP-7 signaling and inhibits bone formation

MicroRNAs (miRNAs) are short non-coding RNAs that interfere with translation of specific target mRNAs and thereby regulate diverse biological processes. Recent studies have suggested that miRNAs might have a role in osteoblast differentiation and bone formation. Here, we show that miR-542-3p, a well-characterized tumor suppressor whose downregulation is tightly associated with tumor progression via C-src-related oncogenic pathways, inhibits osteoblast proliferation and differentiation. miRNA array profiling in Medicarpin (a pterocarpan with proven bone-forming effects) induced mice calvarial osteoblast cells and further validation by quantitative real-time PCR revealed that miR-542-3p was downregulated during osteoblast differentiation. Over-expression of miR-542-3p inhibited osteoblast differentiation, whereas inhibition of miR-542-3p function by anti-miR-542-3p promoted expression of osteoblast-specific genes, alkaline phosphatase activity and matrix mineralization. Target prediction analysis tools and experimental validation by luciferase 3′ UTR reporter assay identified BMP-7 (bone morphogenetic protein 7) as a direct target of miR-542-3p. It was seen that over-expression of miR-542-3p leads to repression of BMP-7 and inhibition of BMP-7/PI3K- survivin signaling. This strongly suggests that miR-542-3p suppresses osteogenic differentiation and promotes osteoblast apoptosis by repressing BMP-7 and its downstream signaling. Furthermore, silencing of miR-542-3p led to increased bone formation, bone strength and improved trabecular microarchitecture in sham and ovariectomized (Ovx) mice. Although miR-542-3p is known to be a tumor repressor, we have identified second complementary function of miR-542-3p where it inhibits BMP-7-mediated osteogenesis. Our findings suggest that pharmacological inhibition of miR-542-3p by anti-miR-542-3p could represent a therapeutic strategy for enhancing bone formation in vivo.     

Rapamycin inhibits osteoblast proliferation and differentiation in MC3T3-E1 cells and primary mouse bone marrow stromal cells

While the roles of the mammalian target of rapamycin (mTOR) signaling in regulation of cell growth, proliferation, and survival have been well documented in various cell types, its actions in osteoblasts are poorly understood. In this study, we determined the effects of rapamycin, a specific inhibitor of mTOR, on osteoblast proliferation and differentiation using MC3T3-E1 preosteoblastic cells (MC-4) and primary mouse bone marrow stromal cells (BMSCs). Rapamycin significantly inhibited proliferation in both MC-4 cells and BMSCs at a concentration as low as 0.1 nM. Western blot analysis shows that rapamycin treatment markedly reduced levels of cyclin A and D1 protein in both cell types. In differentiating osteoblasts, rapamycin dramatically reduced osteoblast-specific osteocalcin (Ocn), bone sialoprotein (Bsp), and osterix (Osx) mRNA expression, ALP activity, and mineralization capacity. However, the drug treatment had no effect on osteoblast differentiation parameters when the cells were completely differentiated. Importantly, rapamycin markedly reduced levels of Runx2 protein in both proliferating and differentiating but not differentiated osteoblasts. Finally, overexpression of S6K in COS-7 cells significantly increased levels of Runx2 protein and Runx2 activity. Taken together, our studies demonstrate that mTOR signaling affects osteoblast functions by targeting osteoblast proliferation and the early stage of osteoblast differentiation.     

Cbfa1/Runx2与成骨细胞分化调控

成骨细胞是由间充质干细胞经骨原细胞和前成骨细胞分化而来的。近年来已鉴定转录因子Cbfal(core binding factor α1)是成骨细胞分化和骨形成的关键调控因子。在成骨细胞分化的过程中,Cbfal通过调控成骨细胞特异性细胞外基质蛋白基因的表达和成骨细胞周期参与成骨细胞的分化过程。新近发现Cbfal能通过自身的PST序列区域与Smads结合形成复合物共同参与成骨细胞的分化调控。     

Insulin stimulates osteoblast proliferation and differentiation through ERK and PI3K in MG‐63 cells

Insulin has been proposed to be an anabolic agent in bone, but the mechanisms underlying insulin effects on osteoblast differentiation are still not clear. To explore the mechanisms of action of insulin on osteoblast growth and differentiation, human osteoblastic cell line‐MG‐63 was used and stimulated by insulin in the presence or absence of ERK inhibitor PD98059, PI3‐K inhibitor LY294002, or inhibitor PD98059 + LY294002. The results showed that insulin positively regulated the expression of its receptor. Insulin stimulated the proliferation of MG‐63 cells in a time‐ and dose‐dependent manner and blockade of both MAPK and PI3K pathways could inhibit the cell proliferation. In addition, ALP activity, the secretion of type I collagen, OC gene expression, and mineralized nodule formation were increased in the insulin treated group, whereas these indicators were decreased after treatment with blocking agents. However, treatment with PI3‐K inhibitor LY294002 significantly reversed the down‐regulation of Runx2 expression and treatment with ERK inhibitor PD98059 remarkably decreased up‐regulation of Osx and IGF‐1 expression after insulin treatment. Therefore, the data obtained from this study suggested that insulin promoted osteoblast proliferation and differentiation through MAPK and PI3K pathway in MG‐63 cells. Copyright © 2010 John Wiley & Sons, Ltd.     

大豆甙元对大鼠成骨细胞增殖与分化的影响

目的探讨大豆甙元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,大豆甙元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。结果大豆甙元1×10(-5)～1×10(-9)mol／L浓度范围内48h,72h促进成骨细胞增殖,在1×10(-7)～1×10(-9)mol／L范围内48h和72h提高成骨细胞外骨钙素含量。结论大豆甙元体外能促进成骨细胞的增殖与分化。     

Effects of hypoxia on the proliferation and differentiation of NSCs

Oxygen is vital to nearly all forms of life on Earth via its role in energy homeostasis and other cell functions. Until recently, the effects of oxygen on the proliferation and differentiation of neural stem cells (NSCs) have been largely ignored. Some studies have been carried out on the basis of the fact that NSCs exists within a “physiological hypoxic” environment at 1 to 5% O₂ in both embryonic and adult brains. The results showed that hypoxia could promote the growth of NSCs and maintain its survival in vitro. In vivo studies also showed that ischemia/hypoxia increased the number of endogenous NSCs in the subventricular zone and dentate gyrus. In addition, hypoxia could influence the differentiation of NSCs. More neurons, especially more doparminergic neurons, were produced under hypoxic condition. The effects of hypoxia on the other kind of stem cell were briefly introduced as additional evidence. The mechanism of these responses might be primarily involved in the hypoxic inducible factor-1 (HIF-1) signal pathway. The present review summarizes recent works on the role of hypoxia in the proliferation and differentiation of NSCs both in vitro and in vivo, and the mechanism involved in HIF-1 signaling pathway behind this response was also discussed.