NR2F2促进小鼠MC3T3-E1前成骨细胞增殖

目的探讨NR2F2基因对小鼠前成骨细胞增殖的影响。方法用实时定量PCR检测mRNA表达量,MTS法检测细胞增殖,流式细胞术检测细胞周期,ELISA-Brdu法检测细胞DNA合成速度。结果在小鼠MC3T3-E1前成骨细胞增殖速度加快时,NR2F2基因的表达增高至对照的4.57±0.30倍(P<0.01)。过表达NR2F2基因促使MC3T3-E1细胞增殖速度加快,细胞数量增加(P<0.01),细胞周期中S期细胞比例明显升高,为对照组的2倍,G2/M期比例也有增加(P<0.05)。过表达NR2F2基因使MC3T3-E1细胞的Brdu掺入率增高,DNA的合成加速(P<0.01)。结论 NR2F2使S期细胞比例增加,促进小鼠前成骨细胞MC3T3-E1的增殖速度。     

人牙周膜干细胞来源外泌体干预成骨细胞MC3T3-E1的增殖和分化

背景:人牙周膜干细胞具有较强的成骨分化能力,人牙周膜干细胞来源外泌体作为牙周膜干细胞分泌的主要成分,对成骨细胞MC3T3-E1增殖和成骨分化的影响尚不明确。目的:探讨人牙周膜干细胞来源外泌体对MC3T3-E1细胞增殖和分化的影响。方法:采用酶消化法分离及培养人牙周膜干细胞,超速离心法提取人牙周膜干细胞来源外泌体,通过透射电镜、粒径分析及Western blot方法对人牙周膜干细胞来源外泌体进行鉴定;CCK8法检测不同质量浓度人牙周膜干细胞来源外泌体对MC3T3-E1细胞增殖的影响,茜素红染色观察100 mg/L人牙周膜干细胞来源外泌体对MC3T3-E1细胞成骨矿化的影响,Western blot检测100 mg/L人牙周膜干细胞来源外泌体干预前后MC3T3-E1细胞内MEK和ERK的磷酸化水平。结果与结论:①透射电镜观察可见外泌体为脂质双分子层形成的囊泡结构,粒径检测显示外泌体直径分布在50-120 nm,集中在79.86 nm,Western blot检测结果显示提取的外泌体中含有CD81,CD63,TSG101的表达;②与对照组相比,人牙周膜干细胞来源外泌体对MC3T3-E1细胞的增殖具有促进作用,且作用呈剂量依赖性;③与对照组相比,人牙周膜干细胞来源外泌体组MC3T3-E1细胞能够形成更多的钙结节;与对照组相比,人牙周膜干细胞来源外泌体组MC3T3-E1细胞内p-MEK及p-ERK蛋白表达量升高;④结果表明,人牙周膜干细胞来源外泌体可以显著促进MC3T3-E1增殖和成骨分化,推测可能与其激活MEK/ERK信号通路有关。     

Tmed2促进体外小鼠前成骨细胞MC3T3-E1增殖

 摘要：目的 研究Tmed2基因对小鼠前成骨细胞增殖的影响。 方法 1.分别在小鼠MC3T3-E1细胞中过表达和抑制Tmed2,检测细胞增殖情况。2. 用雌激素处理细胞后,检测细胞的增殖及Tmed2基因的表达量。荧光实时定量PCR检测mRNA水平,MTS法检测细胞活力和增殖,流式细胞术检测细胞周期,Western blot法检测蛋白水平。结果 过表达Tmed2使MC3T3-E1细胞的增殖速度加快,细胞周期中S期细胞比例明显增加,且Cyclin A 的表达升高。而抑制Tmed2基因表达使MC3T3-E1细胞的增殖速度减慢。雌激素处理使细胞增殖速度加快的同时,Tmed2基因的表达显著增高。结论 Tmed2通过上调Cyclin A 的表达,使S期细胞比例增加,加快小鼠前成骨细胞MC3T3-E1的增殖。此外,Tmed2的表达受雌激素的调控,可能参与雌激素促进MC3T3-E1细胞增殖的作用。     

MC3T3-E1细胞成骨模型的应用及研究进展

骨形成与骨重建涉及各种细胞的协同作用。通过各种体外培养模型,在了解成骨过程的生物学方面取得了显著进展。当前,骨组织工程研究火热,但由于原代人成骨细胞十分有限,这些细胞模型越来越多地被应用。MC3T3-E1细胞是前骨细胞,该细胞在研究骨骼疾病和骨缺损的细胞治疗及组织工程方面具有较大潜力。本文全面回顾了MC3T3-E1细胞成骨模型的培养、鉴定及应用等方面内容。此外,还进一步讨论了该模型的优缺点并提出了几点展望。     

Txndc5介导雌激素诱导的小鼠前成骨细胞MC3T3-E1增殖加快

 目的 研究Txndc5基因在小鼠前成骨细胞增殖中的作用。 方法 用雌激素诱导小鼠前成骨细胞系MC3T3-E1,或在MC3T3-E1细胞中分别用质粒载体过表达Txndc5和用siRNA抑制Txndc5的表达后,Western blot检测Txndc5和细胞周期蛋白水平,荧光实时定量PCR检测Cyclin A的mRNA水平,MTS法和细胞计数法检测细胞增殖速度,流式细胞术检测细胞周期。 结果 雌激素诱导MC3T3-E1增殖加快时,Txndc5的蛋白水平亦上升。抑制Txndc5的表达阻止雌激素的促细胞增殖作用。过表达Txndc5使MC3T3-E1细胞增殖速度加快,S期细胞比例增加,同步化细胞进入细胞周期18h时,过表达Txndc5组Cyclin A 的表达升高,且S期细胞比例为18.69%±4.08%,而对照组仅为8.15%±3.68%。抑制Txndc5的表达则使MC3T3-E1细胞增殖速度减慢,S期细胞比例减少,Cyclin A 的表达下降。抑制Cyclin A的表达减弱Txndc5的促细胞增殖作用。结论 Txndc5通过上调Cyclin A 的表达介导雌激素的促前成骨细胞增殖作用。     

Sema7A干预钛微粒诱导鼠MC3T3-E1成骨细胞的凋亡

BACKGROUND: Semaphorin7A (Sema7A) is a kind of cell surface protein, which can promote the fusion of osteoclasts and the migration of osteoblasts at the same time, affecting the dynamic balance of the bone. It is speculated that Sema7A siRNA may inhibit osteoblast apoptosis induced by titanium particles.OBJECTIVE: To study the effect of Sema7A on the preosteoblast activity inhibited by titanium particles.METHODS:Mouse MC3T3-E1 preosteoblasts at passages 6 and 7 were divided into four groups: in blank control group, MC3T3-E1 cells were cultured alone; in standard control group, cell were cultured with titanium particles; in experimental groups 1 and 2, the cells were cultured with titanium particles+Sema7A overexpression plasmids and titanium particles+Sema7A siRNA, respectively. Apoptotic rate of MC3T3-E1 cells was detected by flow cytometry; the mRNA expression of bone sialoprotein, osteocalcin and type I collagen was detected by Q-PCR; western blot assay was adopted to detect the protein expression of bone sialoprotein, osteocalcin and type I collagen; alizarin red calcium nodule staining was taken to detect the degree of osteoblast mineralization.RESULTS AND CONCLUSION: The expressions of bone sialoprotein, osteocalcin and type I collagen were decreased in the standard control group and experimental group 1, but these expression were significantly increased in the experimental group 2 compared with the standard control group (P < 0.05). Flow cytometry results suggested that the apoptotic rate of osteoblasts in the experimental group 1 was significantly higher than that in the other groups (P < 0.05), and the apoptotic rate in the experimental group 2 was lower than that in the standard control group (P < 0.05). Alizarin red staining showed that there were no obvious mineralized nodules in the experimental group 1, but mineralized nodules formed in the experimental group 2. In brief, the genetic interference technique that inhibits the activity of Sema7A can interfere the process of mouse MC3T3-E1 preosteoblast differentiation inhibited by titanium particles, and thus provide a feasible way for the clinical treatment of wear particles-induced osteolysis using biotechnology.  中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

骨碎补总黄酮联合纳米骨材料促进MC3T3-E1细胞的增殖分化

文题释义： 骨碎补总黄酮：是由水龙骨科植物槲蕨的干燥根茎中提取的有效成分,骨碎补总黄酮能够促进成骨细胞增殖,抑制破骨细胞成熟分化。 Wnt/β-catenin信号通路：是一类高度保守的信号通路,广泛存在于多细胞真核生物中,是皮肤发育过程中出现最早的分子信号,调控毛囊的生长发育和毛囊干细胞的迁移分化。β-catenin作为细胞内信号传导蛋白,是Wnt信号通路激活的一种重要的上皮细胞表面黏附分子,能够进入细胞核内传递Wnt信号,进一步激活靶基因开始转录,启动细胞增殖周期。 背景：前期研究发现,骨碎补总黄酮可促进纳米骨材料表面MC3T3-E1细胞的成骨分化,其作用机制有待进一步研究。 目的：探究骨碎补总黄酮联合纳米骨材料对MC3T3-E1细胞发挥作用的机制。 方法：将MC3T3-E1细胞与纳米骨材料共培养,选取100 mg/L和250 mg/L骨碎补总黄酮进行药物干预,以10 μg/L转化生长因子β刺激为阳性对照组。分组如下：①正常组;②DKK1组：Wnt通路抑制剂DKK1      (0.1 mg/L)阻断Wnt/β-catenin信号通路;③DKK1+转化生长因子β组;④DKK1+100 mg/L骨碎补总黄酮组;⑤DKK1+250 mg/L骨碎补总黄酮组;⑥DKK1+纳米骨+转化生长因子β组;⑦DKK1+纳米骨+100 mg/L骨碎补总黄酮组;⑧DKK1+纳米骨+250 mg/L骨碎补总黄酮组。在干预24,48 h后收获细胞,免疫荧光双染法观察Wnt/β-catenin通路中Wnt与LRP结合情况,Real-time PCR和Western blot检测β-catenin、LRP5、Gsk-3β、Cyclin D1、RUNX2的表达。 结果与结论：①激光共聚焦扫描显微镜下显示DKK1+转化生长因子β组、DKK1+250 mg/L骨碎补总黄酮组、DKK1+纳米骨+转化生长因子β组、DKK1+纳米骨+250 mg/L骨碎补总黄酮组棕黄色染色较明显,表明Wnt与LRP结合较其他组更好;②Real-time PCR和Western blot结果显示,骨碎补总黄酮可促进β-catenin、LRP5、RUNX2的表达,下调GSK-3β的表达,说明骨碎补总黄酮通过激活经典Wnt/β-catenin 信号通路促进成骨细胞增殖分化,且骨碎补总黄酮诱导的基因活化呈剂量依赖性。 ORCID: 0000-0002-2031-8644(李晋玉) 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     

壳聚糖改性聚醚醚酮表征及对MC3T3-E1细胞黏附、增殖的影响

背景：聚醚醚酮的生物惰性表面限制了其医学应用,如何提高聚醚醚酮的生物活性亟待解决。目的：分析壳聚糖生物活性涂层改性聚醚醚酮的表面特征及其对MC3T3-E1细胞增殖、黏附的影响。方法：取圆片状聚醚醚酮材料,依次进行NaBH4、3-氨丙基三乙氧基硅烷、戊二醛水溶液及壳聚糖溶液处理,获得壳聚糖生物活性涂层改性的聚醚醚酮材料。使用X射线光电子能谱、扫描电镜、原子力显微镜与全自动接触角测量仪观察化学处理前后聚醚醚酮材料的表面特征。将MC3T3-E1细胞分别接种于聚醚醚酮与壳聚糖改性聚醚醚酮材料表面,观察细胞的增殖与黏附情况。结果与结论：(1)X射线光电子能谱检测显示,聚醚醚酮材料仅含有C、O元素,壳聚糖改性聚醚醚酮材料含有C、O、N、Si元素;壳聚糖改性聚醚醚酮材料表面的接触角小于聚醚醚酮材料(P <0.05);(2)扫描电镜下可见,聚醚醚酮材料表面有明显的凹槽状起伏,壳聚糖改性聚醚醚酮材料表面存在壳聚糖分子,大小为1.0-2.0μm;原子力显微镜下可见,聚醚醚酮材料表面有较多的微小凹坑,大小约为0.1μm,壳聚糖改性聚醚醚酮材料表面的凹坑增大,大小为0.2-0.5μm,表面粗糙度大于聚醚...     

mTORC1 信号促进前成骨细胞MC3T3-E1 的分化成熟

目的:研究mTORC1 信号对前成骨细胞MC3T3-E1 向成骨细胞分化成熟的调控作用。方法:通过向MC3T3-E1 转染pcDNA3.1-Raptor,对mTORC1 信号相关蛋白Raptor 进行过表达。向MC3T3-E1 转染Raptor siRNA,对mTORC1 信号蛋白Raptor 进行基因沉默。通过Real-time PCR 方法测定Raptor 的基因表达,通过蛋白免疫印迹法测定Raptor 蛋白水平,并通过茜素红染色检测成骨矿化情况,以测定成骨分化程度。通过Real-time PCR 检测成骨分化指标的基因表达。结果:与对照组相比,Raptor 过表达组的Raptor mRNA 和蛋白水平明显增加;茜素红染色结果显示Raptor 过表达组染色更深,说明成骨矿化程度更高;荧光定量PCR 结果显示,Raptor 过表达组的成骨分化标记基因以及成骨转录因子的表达量均高于对照组。与对照组相比,Raptor siRNA 组的Raptor mRNA 和蛋白水平明显降低;茜素红染色结果显示Raptor siRNA 组染色更浅,说明成骨矿化程度更低;荧光定量PCR 结果显示,Raptor siRNA 组的成骨分化标记基因以及成骨转录因子的表达量均低于对照组。结论:mTORC1 信号促进前成骨细胞MC3T3-E1 向成骨细胞分化成熟。     

不同浓度骨碎补总黄酮复合可注射骨修复材料对MC3T3-E1成骨细胞作用的实验研究

目的本实验旨在观察中药骨碎补提取物骨碎补总黄酮(AFDR)复合海藻酸基可注射骨修复材料对成骨细胞MC3T3-E1体外培养的影响。方法将成骨细胞株MC3T3-E1随机分为空白对照组、单纯使用海藻酸基可注射骨修复材料组、AFDR0.04mg/L、0.16mg/L、0.64mg/L、1.28mg/L、5.12mg/L 7组,体外复合海藻酸基可注射骨修复材料,以24h和48h为观察时间点,倒置显微镜观察MC3T3-E1细胞形态,台盼蓝拒染法检测MC3T3-E1存活率,MTT法观察细胞增殖效应,碱性磷酸酶(ALP)活性和骨钙素定量检测分别观察不同浓度骨碎补总黄酮促进MC3T3-E1分化作用,采用Von kossa钙化染色法观察其促MC3T3-E1细胞钙化作用。结果①倒置显微镜下观察复合海藻酸基可注射骨修复材料的MC3T3-E1细胞形态,细胞形态呈三角形、多边形、长梭形等,呈集落样生长,无接触抑制,有伪足伸出,胞液透亮,核圆形。AFDR各组不同程度促进成骨细胞的增殖、分化:7组能不同程度的促进成骨细胞的增殖、分化,与空白对照组比较,以0.16 mg/L和0.64mg/L剂量组的成骨细胞增殖数量最多,1.28mg/L,5.12mg/L的AFDR对细胞增殖作用不明显;②MC3T3-E1平均存活率≥90%;③骨碎补总黄酮(AFDR)0.16 mg/L和0.64mg/L剂量组在培养24小时和48小时,其OD值与空白对照组及组间均有显著性差异,可促进MC3T3-E1细胞增殖(P0.05和P0.01);④AFDR 0.16 mg/L和0.64mg/L剂量组能使MC3T3-E1的ALP活性升高(P0.05);⑤AFDR 0.64mg/L剂量组能促进MC3T3-E1骨钙素合成(P0.05);⑥AFDR 0.16 mg/L和0.64mg/L剂量组均可促进细胞钙化(P0.05)。结论 AFDR可显著促进在海藻酸基可注射骨修复材料上MC3T3-E1的增殖、分化和钙化,其作用具有时间依赖和剂量依赖关系。     

流体剪切力通过下调p21促进 MC3T3-E1成骨细胞增殖

目的 探讨流体剪切力(fluid shear stress, FSS)对成骨细胞p21表达的影响,并明确p21在FSS诱导的成骨细胞增殖过程中的作用。方法 对成骨细胞加载不同时间(0、15、30、45、60 min)、1.2 Pa FSS。用CCK-8实验、EdU实验检测成骨细胞增殖活性。用siRNA p21或pcDNA p21转染成骨细胞,并用Western blotting检测转染效果。Western blotting检测不同干预条件下p21、cyclin D1、CDK4的表达变化。结果 加载1.2 Pa FSS后,p21表达显著下调,且加载45 min后表达水平最低。加载FSS和下调p21表达都显著增强成骨细胞增殖,并增加cyclin D1、CDK4表达。而上调p21表达后,加载FSS不再具有增强成骨细胞增殖和增加cyclin D1、CDK4表达的作用。结论 1.2 Pa FSS能够下调成骨细胞p21表达,在加载45 min时下调最为明显。p21下调对成骨细胞增殖具有促进作用,且FSS通过下调p21促进成骨细胞增殖。     

Micropatterned surfaces for controlling cell adhesion and rolling under flow

Cell adhesion and rolling on the vascular wall is critical to both inflammation and thrombosis. In this study we demonstrate the feasibility of using microfluidic patterning for controlling cell adhesion and rolling under physiological flow conditions. By controlling the width of the lines (50–1000 μm) and the spacing between them (50–100 μm) we were able to fabricate surfaces with well-defined patterns of adhesion molecules. We demonstrate the versatility of this technique by patterning surfaces with 3 different adhesion molecules (P-selectin, E-selectin, and von Willebrand Factor) and controlling the adhesion and rolling of three different cell types (neutrophils, Chinese Hamster Ovary cells, and platelets). By varying the concentration of the incubating solution we could control the surface ligand density and hence the cell rolling velocity. Finally by patterning surfaces with both P-selectin and von Willebrand Factor we could control the rolling of both leukocytes and platelets simultaneously. The technique described in this paper provides and effective and inexpensive way to fabricate patterned surfaces for use in cell rolling assays under physiologic flow conditions.     

Adhesion of MC3T3-E1 cells bound to dentin phosphoprotein specifically bound to collagen type I

Dentin sialophosphoprotein (DSPP) is a member of the SIBLING (small integrin binding N-linked glycoprotein) family of proteins commonly found in mineralized tissues. Dentin phosphoprotein (DPP) is a naturally occurring subdomain of DSPP that contains the cell binding RGD sequence. Previously, the orientation and conformation of other SIBLING family members specifically bound to collagen I have been investigated with respect to their cell adhesion properties. In this study, the orientation of DPP under similar circumstances is examined, and the results are discussed relative to the previous investigations. Radiolabeled adsorption isotherms were developed for DPP adsorbing to both tissue culture polystyrene (TCPS) and collagen coated TCPS. Then, a MC3T3-E1 cell adhesion assay was performed on TCPS and collagen coated TCPS in the presence of identical amounts of adsorbed DPP. It was discovered that there was a significant difference in the number of bound cells on the TCPS and collagen coated TCPS, with a preference for TCPS. Furthermore, a cell inhibition assay was conducted to confirm that the cell binding that occurred was due to specific integrin interactions with the RGD sequence of DPP. These results suggest that the orientation of DPP, rather than its conformation, dictates the accessibility of the cell binding RGD domains of DPP and that the RGD sequence in DPP is less accessible when DPP is specifically bound to collagen. The results obtained in this study are in stark contrast to previous studies with related SIBLING proteins, and suggest that DPP does not play a key role in cell binding to the collagen matrix of developing bone.     

Adhesion of MC3T3-E1 cells to bone sialoprotein and bone osteopontin specifically bound to collagen I

Bone sialoprotein (BSP) and bone osteopontin (OPN) are members of the SIBLING (small integrin-binding ligand, N-linked glycoproteins) family of proteins commonly found in mineralized tissues. Previously, OPN was shown to exhibit a preferential orientation for MC3T3-E1 cell adhesion when it was specifically bound to collagen. In this work, the orientation of BSP under similar circumstances is examined and compared with OPN. Radiolabeled adsorption isotherms were obtained for BSP bound to both tissue culture polystyrene (TCPS) and collagen-coated TCPS. The results show that collagen has the capacity to bind almost twice as much OPN under identical conditions. An in vitro MC3T3-E1 cell adhesion assay was then performed to compare the cell binding ability of BSP on either TCPS or collagen-coated TCPS with identical amounts of adsorbed protein. It was found that there is no significant difference in the cell binding ability of BSP on either of the substrates. For cell binding studies on collagen-coated TCPS, it was shown that there are a greater number of cells bound to substrates with adsorbed OPN as compared with BSP. The preferable orientation of OPN for cell binding coupled with the higher binding capability of collagen for OPN indicates that OPN is more important than BSP for osteoblast adhesion to the collagen matrix. In addition, a cell inhibition assay was performed to show that all of the cell binding that occurred throughout these studies was dependent upon integrin interactions with the RGD cell binding moiety.     

Responses of MC3T3-E1 cells to three dental resin-based restorative materials

This study aimed to examine the influences of three dental resin-based restorative materials on cells associated with hard tissue regeneration using osteoblastic MC3T3-E1 cells. A Bis-GMA-based resin composite [Clearfil AP-X (APX)], an MMA-based resin cement [Superbond C&B (SB)], and a resin-modified glass-ionomer [Fuji Ionomer Type II LC (LC)] were tested. A zinc oxide eugenol cement [Super EBA (EBA)] was included in the study for comparison. MC3T3-E1 cells were cultured on set materials for 3, 7, 14, or 21 days. Cell attachment and proliferation were observed by scanning electron microscopy, and mitochondrial dehydrogenase and alkaline phosphatase (ALP) activities of the cells were evaluated. Cell cultures on polystyrene tissue culture dishes served as controls. On APX and SB, cells demonstrated attachment, spreading, and proliferation similar to the controls. In contract, cells adhered and proliferated poorly on LC and EBA. The mitochondrial function and ALP activity of the cells were significantly suppressed (p < 0.05, Scheffe's F test) throughout the experimental period when cultured on LC or EBA, although APX and SB exhibited less inhibition. The results indicate that APX and SB are less toxic to proliferation and differentiation of MC3T3-E1, suggesting that a smaller influence on cementogenesis on these materials can be expected.     

Pinacidil stimulates osteoblast function in osteoblastic MC3T3-E1 cells

Abstract

This study examined the effect of pinacidil, a nonselective adenosine triphosphate–sensitive potassium channel opener, on the function of osteoblastic MC3T3-E1 cells. Pinacidil caused a significant elevation of collagen synthesis, alkaline phosphatase activity, osteocalcin synthesis and mineralization in the cells (p?<?0.05). Pinacidil significantly decreased the production of osteoclast differentiation inducing factors such as TNF-α, IL-6 and receptor activator of nuclear factor-κB ligand in the presence of antimycin A, which inhibits mitochondrial electron transport. Moreover, pinacidil prevented antimycin A-induced reactive oxygen species and nitrotyrosine production. These results demonstrate that pinacidil may have positive effects on skeletal structure.     

Limonene attenuates methylglyoxal-induced dysfunction in MC3T3-E1 osteoblastic cells

Limonene is a common natural terpene with powerful antioxidative properties. This study investigated the effects of limonene, a terpene found in citrus fruits, on the function of the murine pre-osteoblast cell line, MC3T3-E1 cells. The results showed that limonene treatment significantly elevated collagen synthesis, alkaline phosphatase activity, osteocalcin synthesis, and mineralization in osteoblastic cells. Methylglyoxal (MG), a highly reactive dicarbonyl metabolite, is a major precursor of advanced glycation end products, which are involved in the pathogenesis of diabetic osteopathy. We therefore investigated the effects of limonene on MG-induced cytotoxicity. Pre-treatment of MC3T3-E1 cells with limonene prevented MG-induced cell death and apoptosis. Limonene also reduced MG-triggered endoplasmic reticulum (ER) stress, as indicated by decreases in the levels of the ER-localized transmembrane signal transducers ATF-6 and IRE1. Furthermore, limonene treatment significantly reduced MG-induced autophagic activity and reactive oxygen species release. These results suggest that limonene may prevent the development of diabetic osteopathy.     

Anabolic effect of genistein in osteoblastic MC3T3-E1 cells

Genistein is a natural isoflavone found in Leguminosae. The effect of genistein on osteoblastic MC3T3-E1 cells was investigated. Cells were cultured for 48 h in the presence of genistein (10(-7)-10(-5) M). Genistein (10(-6) and 10(-5) M) caused a significant elevation of protein content, alkaline phosphatase activity, and deoxyriboncleic acid (DNA) content in the cells. The effect of genistein (10-5 M) in increasing protein content, alkaline phosphatase activity and DNA content in the cells was completely prevented by the presence of cycloheximide (10(-6) M), an inhibitor of protein synthesis, suggesting that the isoflavone's effect results from a newly synthesized protein component. The effect of genistein (10(-5) M) in elevating cellular protein content and alkaline phosphatase activity was completely inhibited by the presence of trifluo-perazine (10(-5) M), staurosporine (10(-7) M) or vanadate (10(-6) M), various protein kinase inhibitors. Moreover, genistein (10(-5) M)-increased protein content and alkaline phosphatase activity in the cells was clearly abolished by the presence of anti-estrogen tamoxifen (10(-6) M). The effect of 17beta-estradiol (10(-9) M) in elevating protein and alkaline phosphatase activity in the cells was not enhanced by the presence of genistein (10(-5) M). Genistein's effect might be partly involved in estrogen action. The present study demonstrates that genistein has an anabolic effect on osteoblastic MC3T3-E1 cells.     

High glucose promotes apoptosis and autophagy of MC3T3-E1 osteoblasts

IntroductionDiabetes and osteoporosis are common metabolic diseases. Abnormal high glucose can lead to the apoptosis of osteoblasts. Autophagy is a highly conserved cellular process that degrades proteins or organelles. In the present study, we comparatively analyzed the effects of high glucose and glucose fluctuation on apoptosis and autophagy of MC3T3-E1 osteoblasts.Material and methodsMC3T3-E1 cells were respectively treated with different concentrations of D-glucose: 5.5 mM for the control group, 25 mM for the high glucose group and 5.5/25 mM for the glucose fluctuation group.ResultsHigh glucose and glucose fluctuation decreased MC3T3-E1 proliferation and activated autophagy. Also, high glucose and glucose fluctuation might induce the production of reactive oxygen species, decline the mitochondrial membrane potential and trigger apoptosis. The differences in the glucose fluctuation treatment group were more significant. Moreover, N-acetylcysteine, an antioxidant reagent, dramatically eliminated the intracellular reactive oxygen species induced by high glucose and glucose fluctuation, and significantly inhibited the autophagy and apoptosis in MC3T3-E1 osteoblasts. Furthermore, treatment with chloroquine, an inhibitor of autophagy, significantly increased the apoptosis of MC3T3-E1 osteoblasts.ConclusionsHigh glucose, especially high glucose fluctuation, inhibits proliferation and promotes apoptosis and autophagy of MC3T3-E1 osteoblasts. This may occur through inducing oxidative stress and mitochondrial damage in the osteoblasts.