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.     

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。     

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。     

焦亡介导高糖引起的小鼠胚胎成骨细胞MC3T3-E1炎症与损伤

目的:探讨细胞焦亡(pyroptosis)能否介导高糖(HG;45 mmol/L葡萄糖)引起的小鼠胚胎成骨细胞MC3T3-E1炎症和损伤。方法:应用细胞计数试剂盒8(CCK-8)检测成骨细胞活力;Western blot测定成骨细胞的核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)和胱天蛋白酶1(CASP1)的表达水平;ELISA法测定细胞培养上清液中白细胞介素18(IL-18)和IL-1β的水平;2’,7’-二氯二氢荧光素二乙酯染色荧光显微镜照相法检测胞内活性氧(ROS)水平;罗丹明123染色荧光显微镜照相法测定线粒体膜电位(MMP)水平;碱性磷酸酶(ALP)试剂盒测定成骨细胞早期标志物ALP的活性;茜素红染色观察成骨细胞晚期标志物矿化结节的形成。结果:HG处理MC3T3-E1细胞24 h可明显促进NLRP3和CASP1的表达,引起IL-18和IL-1β的分泌增多,同时可使细胞活力降低,ROS生成和MMP丢失增加,成骨细胞分化与矿化功能下降(表现为ALP活性降低和矿化结节数量减少)。利用siRNA沉默CASP1表达可显著减轻HG引起的上述成骨细胞炎症和损伤。结论:焦亡可介导HG引起的...     

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。     

The expression profile of PKC isoforms during MC3T3-E1 differentiation

Protein kinase C (PKC) is a family of kinases whose isoforms show subtle differences in physiological and biochemical responses, with their expression being cell- specific. We hypothesize that there may be a specific profile of expression of PKC isoforms in differentiating osteoblastic cells (OBC) with individual isoforms having specific functions. Herein, the MC3T3-E1 cell line was used as a differentiating model, which was induced from the pre-osteoblast stage to mature osteoblast and characterized with several phenotypic markers, including alkaline phosphatase activity, osteocalcin and bone sialoprotein. The expression of PKC isoforms was monitored using Western blot analysis. Upon induction of osteogenesis, the intracellular localization of PKC eta and theta was determined using immunofluorescence. Lastly, the effect of P38 MAP kinase inhibition was determined using SB203580. Results show 1) PKC alpha, delta, lambda were all highly expressed in MC3T3-E1 osteoblastic cells, 2) the expression of PKC theta was significantly down-regulated upon induction of osteoblastic differentiation; 3) PKC eta was non-detectable at certain cell culture days; however, was up-regulated as the cells transit from each differentiation phase. The increased expression of PKC eta correlated with increases in OC, BSP levels and alkaline phosphatase activity. Immunofluorescence procedure confirmed the Western blot results with an increase in PKC eta and a decrease in PKC theta upon osteogenic stimulation. The inhibition of p38 resulted in a marked down-regulation of PKC eta. The data demonstrate that there is a specific profile of expression of PKC isoforms in differentiating osteoblasts; the different expression pattern of individual isoforms may be either a consequence of the differentiation itself or plays a role in the regulatory mechanism of osteoblastic differentiation. This study has provided primary information on the temporal pattern of expression of PKC isoforms in the differentiating osteoblast and further insight into their possible role in osteoblastic cell maturation.     

Sunflower seed extract enhances the differentiation of osteoblastic MC3T3-E1 cells

Osteoporosis is recognised as one of the major hormonal deficiency diseases, especially in menopausal women and the elderly. The present study investigated whether treatment with sunflower (Helianthus annuus L.) seed extract (SSE) may affect the function of MC3T3-E1 osteogenic cells. In order to determine the growth and differentiation of osteoblast, MTT (3-(4,5-dimethyl-thiazol-2yl)-2,5-diphenyl tetrazolium bromide) assay, alkaline phosphatase (ALP) activity, collagen synthesis and osteocalcin secretion were performed. Also, the production of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and nitric oxide (NO) in osteoblastic MC3T3-E1 cells was measured. SSE significantly (p<0.05) increased cell growth, ALP activity, collagen content and osteocalcin secretion compared with control. The effect of SSE (50 µg/ml) in increasing cell growth, ALP activity and collagen content was prevented by the presence of 10^?6 M cycloheximide and 10^?6 M ICI182780, suggesting that SSE's effect results from a newly synthesised protein component and might be partly involved in oestrogen action. Treatment with SSE (10 and 50 µg/ml) decreased the 5 µg/ml lipopolysaccharide-induced production of TNF-α, IL-6 and NO in osteoblasts. Our data indicate that the enhancement of osteoblast function by sunflower seed may result in the prevention for osteoporosis and inflammatory bone diseases.     

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     

β-蜕皮甾酮促进小鼠前成骨细胞体外增殖及诱导成骨分化

文题释义：β-蜕皮甾酮：又称蜕皮激素、20-羟基蜕皮甾酮,分子式C₂₇H₄₄O₇,为黄棕色至白色粉末,味苦;主要存在于昆虫、蚕、露水草、牛膝、川牛膝等动植物体内,具有调节血糖血脂、促进胶原蛋白合成、抗疲劳、促进细胞生长和刺激真皮细胞分裂等作用,目前广泛应用于化妆品、医疗以及养殖业等领域。骨形态发生蛋白质2：是从脊椎动物骨骼基质中分离提纯的蛋白质,具有内肽酶活性、表皮生长因子模体,同源二聚体之间以二硫键相连,属于转化生长因子β家族,能诱导骨与软骨形成。骨桥蛋白：存在于矿化和活性沉积区,是一种含有Arg-Gly-Asp(RGD)结构的酸性糖蛋白,它与诱导成骨细胞成熟表型表达和矿化骨基质形成的活性蛋白密切相关。在成矿阶段,骨连接素、纤连蛋白与骨桥蛋白的表达高度相关。Ⅰ型胶原是钙盐沉积和细胞附着的支架,可促进细胞附着并刺激细胞分化。背景：β-蜕皮甾酮作为“植物类雌激素”不仅具有刺激蛋白质合成,促进碳水化合物和脂质代谢,缓解高血糖、高脂血症,以及保护内皮细胞免于凋亡并诱导其增殖的多种生物活性,而且有学者报道其在治疗骨质疏松症、骨折和其他骨骼炎症性疾病方面也有着重要的作用。 目的：观察β-蜕皮甾酮对小鼠前成骨细胞(MC3T3-E1细胞)体外增殖的影响,以及在安全剂量下,β-蜕皮甾酮是否对该细胞具有诱导成骨分化的作用。方法：取第4代MC3T3-E1细胞在成骨诱导分化培养基中培养7,10,14,21,28 d后,检测细胞不同时间段成骨分化蛋白(碱性磷酸酶、Ⅰ型胶原蛋白、骨桥蛋白以及钙化结节)的表达量,以鉴定该细胞是否具有成骨分化的能力;然后将MC3T3-E1细胞接种于含不同终浓度β-蜕皮甾酮(0.01,0.1,1,10,100 µmol/L)的诱导培养基中,分别于第1,2,3,4,5,6,7天利用CCK8法检测细胞的增殖活性;最后设置对照组(普通诱导培养基组)和实验组(普通诱导培养基+β-蜕皮甾酮),在相同条件下进行培养,并测定不同时间段各组细胞成骨标志蛋白的表达量。结果与结论：①MC3T3-E1细胞在成骨诱导培养基刺激下,第10天碱性磷酸酶染色以及Ⅰ型胶原蛋白荧光染色表达较高,同时碱性磷酸酶活性检测也验证了这一结果(P < 0.05);诱导培养第14天骨桥蛋白免疫细胞化学染色也有明显表达;茜红素染色显示成骨诱导后的细胞较对照组结节数量明显增加,第28天比第21天的钙结节形成数目更多、直径更大、颜色更深;②CCK 8法测得β-蜕皮甾酮对MC3T3-E1细胞作用5 d后增殖活性达到最佳,促增殖活性最佳剂量为0.01 µ mol/L、0.1 µmol/L,2种浓度之间差异无显著性意义(P > 0.05);③实验组细胞经β-蜕皮甾酮诱导培养第10天较对照组细胞碱性磷酸酶、Ⅰ型胶原蛋白表达更高;第14天实验组细胞内骨桥蛋白、骨钙素表达更高;第28天2组钙结节染色无明显差异;④结果说明,β-蜕皮甾酮能促进MC3T3-E1细胞体外增殖,且在安全剂量下能提高MC3T3-E1细胞向成骨细胞分化的能力。ORCID: 0000-0001-5641-6353(严才平) 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     

Effects of alpha-TCP and TetCP on MC3T3-E1 proliferation,differentiation and mineralization

Calcium phosphates with high solubility in water such as alpha-tricalcium phosphate (alpha-TCP) and tetracalcium phosphate (TetCP) have received considerable attention as components of bone-substitution materials. However, the osteoblast response to these materials has not yet been clearly understood. This study examined the effects of alpha-TCP and TetCP on osteoblast proliferation, differentiation and mineralization in the culture system of MC3T3-E1 cells. Cells were cultured in a differentiation medium with or without alpha-TCP or TetCP at 1 or 10 microM, and the number of cells attached to the culture plates was determined. To examine osteoblast differentiation, the alkaline phosphatase (ALP) activity was measured and the expression of osteoblastic markers analyzed by RT-PCR. In addition, mineralization was evaluated by staining the calcium deposit with Alizalin red. Culture in the presence of alpha-TCP or TetCP showed no significant influence on cell proliferation. ALP activities of the cells were enhanced by both calcium phosphates for 3d and the expression of type I collagen was promoted at 12h and 1d after incubation. Enhancement of bone-like tissue formation by the addition of alpha-TCP or TetCP at 10 microM was observed after 7d incubation and thereafter. The results of the present study indicate that alpha-TCP and TetCP promote osteogenesis by increasing collagen synthesis and calcification of the extra-cellular matrix.     

纳米壳聚糖对MC3T3-E1成骨细胞生长的影响

背景：已有体内急性毒理实验证实,壳聚糖纳米微囊的半数致死量高于2 000 mg/kg,但其具体致病机制目前尚不明确。 目的：分析纳米壳聚糖作为骨替代材料对MC3T3-E1成骨细胞生长及大鼠肝、肾等器官生理功能的影响。 方法：将MC3T3-E1成骨细胞分别在含0(对照)、10 mg/L、100 mg/L、1 g/L、10 g/L纳米壳聚糖的DMEM培养液中培养,检测各组细胞A值。透射电镜观察10 g/L纳米壳聚糖溶液培养MC3T3-E1成骨细胞24 h后的细胞形态变化。采用PBS制备10 g/L纳米壳聚糖悬浮液,分别以166.67,16.67 mg/kg经腹腔注射至SD大鼠体内4周,每周3次,正常对照组注射等量生理盐水,血清生化指标分析大鼠肝、肾功能,病理切片观察组织形态学改变、炎症细胞浸润情况。 结果与结论：与对照组比较,10 mg/L、100 mg/L、1 g/L、10 g/L的纳米壳聚糖溶液均抑制MC3T3-E1细胞的生长(P < 0.05)。透射电镜见团聚的壳聚糖存在于MC3T3-E1细胞浆中,细胞表面的伪足形成,细胞膜呈波浪状起伏,细胞核变性、碎裂及固缩。与正常对照组比较,注射纳米壳聚糖悬浮液两组大鼠血尿素氮、Na+水平均有明显升高(P < 0.05),高剂量组K+水平明显降低(P < 0.01);肝脏、肾脏均出现组织细胞凋亡现象,高剂量组凋亡更加明显。表明纳米壳聚糖可导致细胞凋亡,超过一定剂量可造成肾功能受损,对机体生理功能造成影响。     

Surface modifications by gas plasma control osteogenic differentiation of MC3T3-E1 cells

Numerous studies have shown that the physicochemical properties of biomaterials can control cell activity. Cell adhesion, proliferation, differentiation as well as tissue formation in vivo can be tuned by properties such as the porosity, surface micro- and nanoscale topography and chemical composition of biomaterials. This concept is very appealing for tissue engineering since instructive properties in bioactive materials can be more economical and time efficient than traditional strategies of cell pre-differentiation in vitro prior to implantation. The biomaterial surface, which is easy to modify due to its accessibility, may provide the necessary signals to elicit a certain cellular behavior. Here, we used gas plasma technology at atmospheric pressure to modify the physicochemical properties of polylactic acid and analyzed how this influenced pre-osteoblast proliferation and differentiation. Tetramethylsilane and 3-aminopropyl-trimethoxysilane with helium as a carrier gas or a mixture of nitrogen and hydrogen were discharged to polylactic acid discs to create different surface chemical compositions, hydrophobicity and microscale topographies. Such modifications influenced protein adsorption and pre-osteoblast cell adhesion, proliferation and osteogenic differentiation. Furthermore polylactic acid treated with tetramethylsilane enhanced osteogenic differentiation compared to the other surfaces. This promising surface modification could be further explored for potential development of bone graft substitutes.     

Effect of gypsum on proliferation and differentiation of MC3T3-E1 mouse osteoblastic cells

Recently, calcium sulfate dihydrate has been demonstrated as safe biodegradable osteoconductive bone void filler. However, its exact mechanism of action on bone cells is yet unknown. In this study, the influence of gypsum on gene expression and proliferation of MC3T3-E1 mouse pre-osteoblastic cells was investigated. Cells were cultured on gypsum disc, slice, polymethylmethacrylate (PMMA), or plastic culture plate for 15 days. Cell viability, alkaline phosphatase (ALP) activity and expression profile of 15 genes involved in bone metabolism were measured in cultures. Cell proliferation on gypsum was increased by almost 2-fold, while an inhibitory effect of PMMA on proliferation rate of osteoblasts was noted. Cells cultured on gypsum disc surface exhibited an increased ALP activity and markedly different gene expression profile. Quantitative real-time PCR data indicated the expression of genes that might provide a basis for an osteoinductive potential. MC3T3-E1 cells expressed genes typical of bone fracture healing like type II collagen and fibronectin 1. These effects might be related to the calcium content of gypsum and mediated likely via SMAD3. Our results suggest that gypsum can support new bone formation by its calcium content and modulatory effect on gene expression profile of bone cells.     

Three-dimensional growth of differentiating MC3T3-E1 pre-osteoblasts on porous titanium scaffolds

The present work assesses the potential of three-dimensional porous titanium scaffolds produced by a novel powder metallurgy process for applications in bone engineering through in vitro experimentation. Mouse MC3T3-E1 pre-osteoblasts were used to investigate the proliferation (DNA content), differentiation (alkaline phosphatase activity and osteocalcin release) and mineralisation (calcium content) processes of cells on titanium scaffolds with average pore sizes ranging from 336 to 557 microm, using mirror-polished titanium as reference material. Scanning electron microscopy was employed to qualitatively corroborate the results. Cells proliferate on all materials before reaching a plateau at day 9, with proliferation rates being significantly higher on foams (ranging from 123 to 163 percent per day) than on the reference material (80% per day). Alkaline phosphatase activity is also significantly elevated on porous scaffolds following the proliferation stage. However, cells on polished titanium exhibit greater osteocalcin release toward the end of the differentiation process, resulting in earlier mineralisation of the extracellular matrix. Nevertheless, the calcium content is similar on all materials at the end of the experimental period. Average pore size of the porous structures does not have a major effect on cells as determined by the various analyses, affecting only the proliferation stage. Thus, the microstructured titanium scaffolds direct the behaviour of pre-osteoblasts toward a mature state capable of mineralising the extracellular matrix.     

The alignment of MC3T3-E1 osteoblasts on steps of slip traces introduced by dislocation motion

Bone tissue shows a highly anisotropic microstructure comprising biological apatite and collagen fibrils produced by the mutual activities of bone cells, which dominates its mechanical function. Accordingly, directional control of osteoblasts is crucial for forming anisotropic bone tissue. A new approach was proposed for controlling cell directionality by using crystallographic slip traces caused by dislocation glide. Dislocations were introduced into α-titanium single crystals by plastic deformation of (011ˉ0)[21ˉ1ˉ0] slip system, inducing a step-like structure with acute angles between the surface normal and the slip plane. Topographical properties of step patterning, including step interval and step height, could be controlled by varying the compressive plastic strain. The step geometry introduced by plastic deformation strongly influenced osteoblast elongation, and it aligned preferentially along slip traces. Ti substrates under 10% plastic strain with step height of approximately 300?nm and step interval of 10?μm induced osteoblast alignment most successfully. Actin stress fibers elongated parallel to slip traces, with polarized vinculin accumulation between steps.     

Gel microstructure regulates proliferation and differentiation of MC3T3-E1 cells encapsulated in alginate beads

For cell transplantation into damaged tissues, viable cells must be delivered to the defect site in a suitable carrier. However, the hypoxic and nutrient-limited environment in the carrier can induce massive cell death. The aims of this study were to increase the viability and regulate the behavior of osteoprogenitor cells encapsulated in alginate hydrogels through control of the gel microstructure. Cell survivability in alginate beads was improved through the use of α-MEM as the solvent for alginic acid sodium salt, and by CaCl(2) solutions, which supplied additional nutrients for the cells compared to water or buffer. The mesh size and shear modulus of the hydrogel were hypothesized to regulate proliferation and differentiation of osteoprogenitor cells. MC3T3-E1 cells demonstrated enhanced osteoblast differentiation when encapsulated in high-density alginate with smaller mesh size and more rigid mechanical properties, as confirmed by increased alkaline phosphatase activity and osteocalcin secretion. However, MC3T3-E1 cells encapsulated in low-density alginate beads with a larger mesh size and more compliant mechanical properties exhibited increased proliferation. These results demonstrate that the microstructure of alginate hydrogels can regulate the behavior of osteoprogenitor cells, thus suggesting that the tuning the properties of the gel may be a useful approach for enhancing new bone formation.     

MC3T3-E1成骨细胞在微格式化表面的黏附

细胞在材料表面的黏附对细胞的增殖和分化志重要作用。格式化表面提供了对细胞在基底的空间分布和黏附进行控制的方法。本文利用微制作利用微制作形成的格式模板，分别以微接触转印法和微流道法形成格式化表面，使MC3T3－E1成骨细胞以一定的格式黏附于表面上，在微接触转印法形成的含二氯二甲基硅烷（DMS）的疏水区域和不含DMS的亲水区域相间隔的表面，细胞优先在亲水区域黏附，在微流道法形成的胶原和白蛋白格式化表面，细胞优先黏附于含胶原区域，结果还表明微格式化表面可以用于研究表面的物理化学性质对细胞的黏附等功能的影响。     

Icariin stimulates MC3T3-E1 cell proliferation and differentiation through up-regulation of bone morphogenetic protein-2

Previous studies suggest that icariin has anabolic effects on bone, but the mechanisms are unknown. We aimed to investigate the osteogenic effects of icariin in an undifferentiated osteoblast cell line by detecting cell morphology, viability, cell cycling and bone morphogenetic protein-2 (BMP-2) expression. We treated pre-osteoblastic MC3T3-E1 cells with different concentrations of icariin [0 (as a control), 10, 20 and 40 ng/ml] for 48, 72 and 96 h. Cell morphology, viability and the cell cycle were examined and measured using microscopy, the MTT assay or flow cytometry, respectively. BMP-2-positive cells and BMP-2 protein expression levels in icariin-treated MC3T3-E1 cells were examined using immunohistochemistry staining with fluorescence optical density analysis and Western blotting. MC3T3-E1 cells showed typical characteristics of osteoblasts in response to treatment with icariin. Cells treated with all concentrations of icariin had increased percentages of S-phase cells and decreased percentages of G1-phase cells, especially in the 10 and 20 ng/ml icariin groups. The number of BMP-2-positive cells and BMP-2 protein expression levels in the 10 and 20 ng/ml icariin treatment groups were greater compared to the 0 and 40 ng/ml groups. Treatment of icariin promotes osteoblast MC3T3-E1 proliferation and differentiation in vitro, potentially owing to its role in increasing BMP-2 protein expression. Icariin potentially can be used as a drug in clinical settings to treat osteoporosis.     

miR-132-3p过表达对MC3T3-E1细胞增殖分化的影响

文题释义： miRNA：是一类小的非编码RNA,长度约为22个核苷酸,其主要通过结合靶标mRNA的3'UTR区诱导靶标mRNA降解或抑制其翻译,从而在转录及转录后水平调控相关基因的表达。miRNA在细胞增殖、分化及凋亡等多种生物学活动过程中起着非常重要的调控作用,并且发现它是调控骨组织细胞增殖和分化过程的重要因子之一。 MC3T3-E1细胞：是新生C57BL/6小鼠颅顶骨中分离培养所建立的一株成骨细胞株,它能够展现骨组织中成骨细胞的各个发育阶段和各种生物学特性。作为研究成骨细胞增殖和分化的理想模型,被广泛应用于国内外各种骨组织工程学研究。 背景：机械牵引力能够影响MC3T3-E1细胞的增殖分化过程,并引起细胞内miR-132-3p的差异表达。然而,牵引力是否通过调控miR-132-3p的表达来影响成骨细胞增殖分化仍需进一步研究。 目的：明确12%牵引力作用下MC3T3-E1细胞中成骨分化标志因子及miR-132-3p表达变化,并进一步探讨miR-132-3p对细胞增殖分化的影响。 方法：MC3T3-E1细胞分别加载0%,12%牵张应力,检测应力加载后碱性磷酸酶活性、骨钙蛋白及miR-132-3p mRNA的表达水平;细胞内瞬时转染miR-132-3p模拟物及其阴性对照,qRT-PCR检测转染后碱性磷酸酶、骨钙蛋白、Runt标志转录因子2 mRNA的表达,CCK-8法检测miR-132-3p对细胞增殖能力的影响。 结果与结论：①12%牵张应力作用下,MC3T3-E1细胞中碱性磷酸酶活性、骨钙蛋白mRNA表达水平下调(P < 0.01),miR-132-3p表达水平显著升高(P < 0.05);②细胞内转染miR-132-3p后,miR-132-3p模拟物组成骨分化标志因子碱性磷酸酶、骨钙蛋白、Runt标志转录因子2 mRNA表达水平显著降低(P < 0.05);③相比于阴性对照组,miR-132-3p 模拟物转染24,48,72 h后细胞增殖能力明显降低(P < 0.001),且在转染48 h后降低最明显;④结果说明12%周期性循环牵张应力能够通过过表达miR-132-3p负向调节MC3T3-E1细胞的增殖和成骨分化。 ORCID: 0000-0003-0696-3329(孙芬) 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