小鼠骨髓源性树突状细胞体外诱导培养方法的比较研究

目的探讨最佳体外诱导培养小鼠成熟树突状细胞（dendritic cells,DC）的方法。方法分离、纯化6周龄C57BL／6小鼠骨髓单核细胞,以含10％胎牛血清、20ng／ml重组小鼠粒细胞-巨噬细胞集落刺激因子（GM—CSF）和10ng／ml重组小鼠白细胞介素-4（IL-4）的RPMI-1640培养基培养7d,然后将细胞分成对照未刺激组、肿瘤坏死因子-α（TNF-α）刺激组和TNF-α＋脂多糖（lipopolysaccharides,LPS）刺激组。继续培养48h后,观察各组细胞形态,检测IL-12、IL-6浓度及细胞表面标志CD11c、CD80、CD86和MHC II。结果培养9d后,两刺激组培养的细胞经相差显微镜观察有DC生长。TNF—α刺激组细胞培养上清液中IL-6、IL-12含量显著高于对照组（P〈0．01）,但显著低于TNF—α＋LPS刺激组（P〈0．05）。3组均高表达CD11c,各组间无显著差异;而CD80、CD86和MHC II表达阳性率TNF-α刺激组显著高于对照组（P〈0．01）,TNF-α＋LPS刺激组显著高于单纯TNF—α刺激组（P〈0．05）。结论联合使用TNF-α与LPS刺激可使DC成熟度提高,分泌IL-6、IL-12增加。     

TNF—α对哮喘模型大鼠气道平滑肌细胞增殖及ERK1／2活性的影响

目的探讨TNF—α对哮喘大鼠气道平滑肌细胞（ASMCs）增殖及对ASMCs上ERK1／2mRNA、p-ERK1／2表达水平的影响。方法通过对哮喘模型大鼠ASMCs培养,分别以0．2μg／L、1．0μg/L、20μg/L TNF-α干预ASMCs生长。采用流式细胞仪、MTT法检测ASMCs增殖情况,观察不同浓度TNF—α对ASMCs增殖的影响。RT-PCR检测ASMCs上ERK1／2mRNA表达,免疫细胞化学染色法检测磷酸化ERK1／2蛋白的表达及定位。结果哮喘组ASMCsS期比例、A值、ERK1／2mRNA、p-ERK1／2蛋白的表达量分别为（34．45±2．08）％、（0．550±0．010）、（0．995±0．118）、（130．77±4．16）,与对照组（11．17±0．96）％、（0．292±0．008）、（0．576±0．098）、（163．82±1．38）比较均显著增高（均P〈0．01）。各TNF—α干预组ASMCs的S期比例、A值、ERK1／2mRNA和p-ERK1／2蛋白表达量与哮喘组比较均显著降低（均P〈0．01）,0．2μg/L和1．0μg／LTN-α组p-ERK1／2蛋白表达量高于对照组（P〈0．01）,20μg／L TNF-α组p-ERK1／2蛋白表达量与对照组比较无差异（P〉0．05）。结论与正常鼠相比,慢性哮喘大鼠气道平滑肌细胞增殖明显,处于S期的细胞比例明显增高。经TNF—α干预后,慢性哮喘大鼠气道平滑肌细胞处于S期的细胞比例减少,增殖减弱,TNF-α可能抑制慢性哮喘大鼠气道平滑肌细胞增殖。TNF—α可下调慢性哮喘大鼠气道平滑肌细胞上ERK1／2mRNA及p-ERK1／2表达,TNF-α可能通过抑制ERK信号转导通道的活性对气道平滑肌细胞的增殖进行调控。     

miR-29b对TNF—α诱导的人脐静脉内皮细胞增殖与凋亡的影响

目的探索过表达miR-29b对TNF-α 诱导的人脐静脉内皮细胞（HUVECs）增殖与凋亡的影响及初步作用机制。方法MTT 法筛选TNF—α诱导HUVECs的最佳浓度和时间,建立细胞凋亡模型;MTY法筛选miR-29bmimic转染HUVECs的最佳转染时间和浓度：MTr法检测过表达miR-29b对TNF-α诱导HUVECs增殖活力的影响;Hoechst33342荧光染色检测过表达miR-29b对TNF—α诱导HUVECs凋亡的影响：Western印迹技术检测过表达miR-29b对Akt磷酸化水平、Bcl-2蛋白表达的影响。结果TNF—α诱导的HUVECs凋亡的最佳浓度为10ng／ml,最佳时间是48h;miR-29bmimics转染HUVECs的最佳浓度为50nmol/L,最佳作用时间是48h;过表达miR-29b能显著降低TNF-α诱导的HUVECs的增殖活力（P〈0．001）;Heochst33342荧光染色结果显示。miR-29b过表达能促进TNF-α诱导的HUVECs的凋亡（P〈0．05）;过表达miR-29b能显著下调Akt磷酸化（p-Akt）与Bcl-2蛋白的表达（P〈0．001）。结论过表达miR-29b可降低TNF-α诱导的HUVECs的增殖活力并促进其凋亡,其机制可能与下调Akt磷酸化、Bd-2蛋白的表达相关。     

CD8＋CD122＋T细胞在脑缺血过程中作用的研究

目的：探讨CD8＋CD122＋T细胞在脑缺血过程中的作用及其机制。方法：线栓法建立小鼠大脑中动脉栓塞模型（MCAO）;激光共聚焦显微镜检测小鼠脑缺血组织中CD8＋CD122＋T细胞浸润情况;流式细胞仪检测脑缺血组织中CD8＋CD122＋T细胞／CD3＋T细胞的比例及脾和胸腺中CD8＋CD12TT细胞数量变化;RT—PCR方法检测CD8＋CD122＋T细胞对氧糖剥夺（Oxygen—glucosedeprivation,OGD）条件下星形胶质细胞表达TNF-α,IL-1β,IFN-γ的影响。结果：各时间点脑缺血组织中均有CD8＋CD122＋T胞浸润,且随脑缺血时间延长,缺血侧脑组织中CD8＋CD122＋T细胞／CD3＋T细胞比例逐渐增加,5d和7d组差异显著,与非缺血侧相比,P5d〈0．05,P7d〈0．05;MCAO小鼠脾及胸腺中CD8＋CD122＋T细胞呈现先增高后降低的趋势。星形胶质细胞经OGD处理后,与对照组相比,IFN-γ、TNF-α、IL—1β表达显著增高,PIFN-γ〈0．01、PTNF-α〈0．001、PIL-1β〈0．01;CD122-blocked组与CD8＋组相比,IFN-γ、TNF-α、IL-1β表达明显增高,PIFN-γ〈0．05、PINF-α〈0．05、PIL-1β〈0．01;CD8＋组与HBSS组相比,IFN-γ表达降低,P〈0．05;IL-1β表达有降低的趋势。结论：CD8＋CD122可细胞在脑缺血过程中发挥保护性作用,其保护作用通过CD122抑制星形胶质细胞TNF-α,IL-1β,IFN-γ炎症因子表达实现的。     

AGEs和TNF-α对人牙周膜干细胞骨向分化能力的协同抑制作用

本实验旨在研究糖基化终末产物(AGE-BSA)和TNF-α对人牙周膜干细胞增殖及骨向分化能力的影响。本实验通过体外组织块酶消化法和有限稀释法克隆化培养牙周膜干细胞,使用流式细胞仪检测细胞表型分子stro-1、CD146、CD44、CD90的表达而对其进行干细胞鉴定后,取第3代人牙周膜干细胞在100μg/mL AGE-BSA及10 ng/mL TNF-α刺激下进行增殖能力检测;同时矿化诱导,设A组(AGE-BSA刺激组),T组(TNF-α刺激组),AT组(AGE-BSA/TNF-α共同刺激组),不含AGE-BSA/TNF-α的常规矿化诱导组作为对照;于诱导的21d茜素红染色观察钙结节形成情况,诱导7 d,碱性磷酸酶染色观察ALP活性、实时定量聚合酶链反应(real time PCR)和Western blotting检测成骨相关基因及蛋白表达情况。流式细胞仪显示细胞阳性表达STRO-1、CD146、CD44、CD90;成骨诱导21 d后茜素红染色和定量分析显示,AT组骨结节形成量最低,A组及T组相对于对照组骨结节形成量存在下降;差异均有统计学意义(p0.05)。成骨诱导7 d后ALP染色,ALP活性变化趋势与茜素红定量分析相同。成骨诱导7 d后RT-PCR检测成骨相关基因BSP、OCN、ALP mRNA表达,AT组表达水平最低,A组及T组有下降趋势,差异均有统计学意义(p0.05)。Western blotting检测显示,各组总蛋白BSP蛋白表达趋势与RT-PCR趋势相同。AGEs与TNF-α均具有对HPDLSC的骨向分化能力的抑制作用,两者共同刺激对HPDLSC骨向分化能力存在协同抑制作用。     

去卵巢骨质疏松山羊骨髓基质细胞成骨分化能力的研究

目的：研究在构建的去卵巢骨质疏松山羊动物模型中,骨髓基质细胞（MSCs）的生物学特性以及其成骨能力。方法：建立去卵巢骨质疏松山羊动物模型,使用全骨髓法获取去卵巢骨质疏松山羊（实验组）和正常山羊（对照组）MSCs,流式细胞仪检测实验组和对照组细胞周期及增殖指数（PI）;地塞米松诱导21d时油红O染色,观察成脂分化比例;成骨诱导液诱导14d,碱性磷酸酶（ALP）染色、检测ALP表达量。结果：对照组PI高于实验组;地塞米松诱导后实验组脂肪细胞比例明显高于对照组;成骨诱导第7d,对照组ALP的表达量明显高于实验组。结论：去卵巢骨质疏松山羊的MSCs增殖和成骨分化能力都降低,可能与骨质疏松症的发病机理有关。     

糖浓度及BMP4对小鼠诱导型多能干细胞成骨作用的研究

诱导型多能干细胞（induced pluripotent stem cells,iPS cells）技术的建立为自体组织工程治疗带来了新的希望。鉴于糖尿病患者常伴有骨再生性障碍,该研究比较了不同葡萄糖浓度下小鼠iPS细胞的成骨能力,并探讨了骨形态蛋4（bone morphogenetic protein4,BMP4）在该过程中的作用。实验结果显示：成骨诱导21d后,低糖组茜素红阳性细胞比例和成骨基INRunx2、Osteocalcin的表达水平显著高于高糖组和自发分化组（P〈0．05）;BMP4的添加提高了高糖组茜素红阳性细胞比例及Osteocalcin的表达水平（P〈0．05）,而对自发分化组细胞的成骨水平无影响。该结果表明：低葡萄糖含量对小鼠iPS细胞的骨向分化有促进作用’尽管BMP4可以提高高糖组小鼠iPS细胞的成骨能力,但仅在成骨分化条件下发挥作用。     

葛根素预防雌激素缺乏性骨质疏松的机制探讨

目的观察葛根素对去卵巢大鼠股骨骨密度、颌骨骨密度和血清中肿瘤坏死因子（TNF-α）、C反应蛋白（CRP）及雌二醇（E2）水平的影响。方法 3月龄雌性SD大鼠随机分为假手术组（sham group）、单纯去势组（OVX group）、去势＋雌二醇治疗组（OVX-estrogen group）和去势＋葛根素治疗组（OVX-puerarin group）。给药3个月后测量各组大鼠股骨和颌骨骨密度,血清中TNF-α和CRP及雌二醇（E2）水平。结果 OVX-puerarin组较sham组体重明显增加（P〈0.01）;较OVX-estrogen组的TNF-α（P〈0.01）、CRP（P〈0.05）及E2（P〈0.01）水平显著下降;其下颌骨和股骨远端骨密度与OVX组、sham组之间无显著性差异,但其股骨近端骨密度较OVX-estrogen组明显增加（P〈0.05）。结论葛根素作为抗炎因子,能够显著降低TNF-α和CRP的水平,但并不会提高雌激素的水平;葛根素对卵巢切除所致的骨质疏松症有一定的治疗作用,但会明显提高机体体重。     

连翘酯苷对小鼠脾脏淋巴细胞体外增殖与分泌功能的影响

目的分析连翘酯苷（FS）对小鼠脾脏T和B淋巴细胞增殖、分泌NO和TNF-α的影响,初步探讨其免疫调节作用机制。方法无菌操作分离小鼠脾脏,制备脾脏细胞并用含10%胎牛血清的RPMI 1640培养,在培养液中分别加入刺激剂刀豆蛋白（ConA）和脂多糖（LPS）以及不同浓度40、80、160μg/mL的FS共培养不同时间,采用MTT法检测T和B淋巴细胞的吸光度变化,ELISA和Griess法分别检测细胞分泌TNF-α和NO的水平。结果低浓度和中浓度FS对ConA诱导T淋巴细胞24 h和48 h后细胞增殖和存活率明显提高,诱导时间延长至72 h后FS明显抑制细胞转化;低浓度FS对LPS诱导脾脏B淋巴细胞24 h后细胞增殖和生存率显著提高;FS促进小鼠脾脏T和B淋巴细胞分泌NO;FS促进B淋巴细胞分泌TNF-α,中浓度FS促进T淋巴细胞分泌TNF-α而高浓度反而抑制其分泌。此外,FS对环磷酰胺（CY）处理小鼠的脾脏淋巴细胞体外增殖有明显影响,对细胞NO分泌影响不显著。结论结果提示FS可能通过影响小淋巴细胞增殖和细胞因子分泌而调节免疫细胞功能。     

Shh信号参与调控BMP9诱导的间充质干细胞成骨分化

目的：观察sonic hedgehog（Shh）信号通路在骨形态发生蛋白9（BMP9）诱导的小鼠间充质干细胞（MSCs）C3H10T1/2和C2C12成骨分化中的作用,并初步探讨其作用机制。方法：Shh信号通路抑制剂Cyclopamine和激活剂Purmorphamine以及过表达Shh腺病毒分别作用于BMP9处理的C3H10T1/2和C2C12细胞,碱性磷酸酶（ALP）检测早期成骨指标ALP,茜素红S染色检测晚期成骨指标钙盐沉积,RT-PCR检测Shh信号相关基因以及成骨关键转录因子的表达,Western blot检测Shh的表达,荧光素酶报告基因检测Smad1/5/8的转录调控活性。结果：BMP9促进Shh信号相关基因的表达,激活Shh信号可增强BMP9诱导的C3H10T1/2和C2C12细胞早晚期成骨分化并促进了BMP9诱导的Smad荧光素酶活性,抑制Shh信号后作用相反。结论：激活Shh信号通路可促进BMP9诱导的小鼠MSCs成骨分化,抑制其活性后作用相反。     

GDNF secreted by pre-osteoclasts induces migration of bone marrow mesenchymal stem cells and stimulates osteogenesis

Bone resorption is linked to bone formation via temporal and spatial coupling within the remodeling cycle. Several lines of evidence point to the critical role of coupling factors derived from pre-osteoclasts (POCs) during the regulation of bone marrow-derived mesenchymal stem cells (BMMSCs). However, the role of glial cell-derived neurotrophic factor (GDNF) in BMMSCs is not completely understood. Herein, we demonstrate the role of POC-derived GDNF in regulating the migration and osteogenic differentiation of BMMSCs. RNA sequencing revealed GDNF upregulation in POCs compared with monocytes/macrophages. Specifically, BMMSC migration was inhibited by a neutralizing antibody against GDNF in pre-osteoclast-conditioned medium (POC-CM), whereas treatment with a recombinant GDNF enhanced migration and osteogenic differentiation. In addition, POC-CM derived from GDNF knockdowned bone marrow macrophages suppressed BMMSC migration and osteogenic differentiation. SPP86, a small molecule inhibitor, inhibits BMMSC migration and osteogenic differentiation by targeting the receptor tyrosine kinase RET, which is recruited by GDNF into the GFRα1 complex. Overall, this study highlights the role of POC-derived GDNF in BMMSC migration and osteogenic differentiation, suggesting that GDNF regulates bone meta-bolism.     

Effect of low‐level laser therapy and oxytocin on osteoporotic bone marrow‐derived mesenchymal stem cells

Postmenopausal osteoporosis (OP) is a major concern for public health. Low‐level laser therapy (LLLT) has a positive effect on the health of bone marrow mesenchymal stem cells (BMMSCs). The purpose of this study is to evaluate the influence of LLLT and oxytocin (OT) incubation—individually and in combination—on osteoporotic BMMSCs in ovariectomized rats. Twelve female rats were randomized into two groups to undergo either a sham surgery (sham group) or ovariectomy‐induced osteoporosis (OVX group). MSCs harvested from the BM of healthy and OVX rats underwent culture expansion. There were five groups. In Groups one (sham‐BMMSC) and two (OVX‐BMMSC) the cells were held in osteogenic condition medium without any intervention. In the group three (OT), OT incubation with optimum dose was performed for 48 h (two times, 10^?12 molar). In Group four, laser‐treated‐OVX‐BMMSCs were treated with optimum protocol of LLLT (one time, 1.2 J/cm²). In Group five (laser + OT group), the OT incubation plus the laser irradiation was performed. The biostimulatory effect of LLLT is demonstrated by a significant increase in the viability of OVX‐BMMSCs, cell cycle, and extracellular levels of Transforming growth factor beta (TGF‐β), insulin‐like growth factor‐I (IGF‐I), and Alkaline phosphatase (ALP) compared to control OVX‐BMMSCs and/or the sham group. OT incubation and laser + OT incubation have a positive effect on OVX‐BMMSCs. However, LLLT is more effective statistically. We conclude that LLLT significantly improved cell viability, enhanced the osteogenic potential of the OVX‐BMMSCs, and increased the extracellular levels of the TGF‐β, IGF‐I, and ALP.     

Comparison of gingiva‐derived and bone marrow mesenchymal stem cells for osteogenesis

Presently, bone marrow is considered as a prime source of mesenchymal stem cells; however, there are some drawbacks and limitations. Compared with other mesenchymal stem cell (MSC) sources, gingiva‐derived mesenchymal stem cells (GMSCs) are abundant and easy to obtain through minimally invasive cell isolation techniques. In this study, MSCs derived from gingiva and bone marrow were isolated and cultured from mice. GMSCs were characterized by osteogenic, adipogenic and chondrogenic differentiation, and flow cytometry. Compared with bone marrow MSCs (BMSCs), the proliferation capacity was judged by CCK‐8 proliferation assay. Osteogenic differentiation was assessed by ALP staining, ALP assay and Alizarin red staining. RT‐qPCR was performed for ALP, OCN, OSX and Runx2. The results indicated that GMSCs showed higher proliferative capacity than BMSCs. GMSCs turned more positive for ALP and formed a more number of mineralized nodules than BMSCs after osteogenic induction. RT‐qPCR revealed that the expression of ALP, OCN, OSX and Runx2 was significantly increased in the GMSCs compared with that in BMSCs. Moreover, it was found that the number of CD90‐positive cells in GMSCs elevated more than that of BMSCs during osteogenic induction. Taking these results together, it was indicated that GMSCs might be a promising source in the future bone tissue engineering.     

Human adipose-derived stem cells display myogenic potential and perturbed function in hypoxic conditions

Here, we enriched a human cell population from adipose tissue that exhibited both mesenchymal plasticity, self-renewal capacity, and a cell-surface marker profile indistinguishable from that of bone marrow-derived mesenchymal stem cells. In addition to adipogenic and osteogenic differentiation, these adipose-derived stem cells displayed skeletal myogenic potential when co-cultured with mouse skeletal myocytes in reduced serum conditions. Physical incorporation of stem cells into multinucleated skeletal myotubes was determined by genetic lineage tracing, whereas human-specific antibody staining was employed to demonstrate functional contribution of the stem cells to a myogenic lineage. To investigate the effects of hypoxia, cells were maintained and differentiated at 2% O(2). In contrast with reports on bone marrow-derived stem cells, both osteogenic and adipogenic differentiation were significantly attenuated. In summary, the relative accessibility of adipose-derived mesenchymal stem cells from human donors provides opportunity for molecular investigation of mechanistic dysfunction in disease settings and may introduce new prospects for cell-based therapy.     

LncRNA SNHG1 modulates adipogenic differentiation of BMSCs by promoting DNMT1 mediated Opg hypermethylation via interacting with PTBP1

Recent evidence indicates that the abnormal differentiation of bone marrow‐derived mesenchymal stem cells (BMSCs) plays a pivotal role in the pathogenesis of osteoporosis. LncRNA SNHG1 has been found to be associated with the differentiation ability of BMSCs. In this study, we aimed to elucidate the role of lncRNA SNHG1 and its associated pathway on the differentiation of BMSCs in osteoporosis. Mice that underwent bilateral ovariectomy (OVX) were used as models of osteoporosis. Induced osteogenic or adipogenic differentiation was performed in mouse BMSCs. Compared to sham animals, lncRNA SNHG1 expression was upregulated in OVX mice. Also, the in vitro expression of SNHG1 was increased in adipogenic BMSCs but decreased in osteogenic BMSCs. Moreover, overexpression of SNHG1 enhanced the adipogenic capacity of BMSCs but inhibited their osteogenic capacity as determined by oil red O, alizarin red, and alkaline phosphatase staining, while silencing of SNHG1 led to the opposite results. LncRNA SNHG1 interacting with the RNA‐binding polypyrimidine tract‐binding protein 1 (PTBP1) promoted osteoprotegerin (Opg) methylation and suppressed Opg expression via mediating DNA methyltransferase (DNMT) 1. Furthermore, Opg was showed to regulate BMSC differentiation. Knockdown of SNHG1 decreased the expressions of adipogenic related genes but increased that of osteogenic related genes. However, the knockdown of Opg partially reversed those effects. In summary, lncRNA SNHG1 upregulated the expression of DNMT1 via interacting with PTBP1, resulting in Opg hypermethylation and decreased Opg expression, which in turn enhanced BMSC adipogenic differentiation and contributed to osteoporosis.     

Icariin promotes osteogenic differentiation of bone marrow stromal cells and prevents bone loss in OVX mice via activating autophagy

Osteoporosis (OP) results from the impaired function of endogenous bone marrow mesenchymal stem cells (BMSCs). Icariin (ICA) has shown potential osteoprotective effects. However, the molecular mechanism for the anabolic action of ICA remains largely unknown. The objective of the present study is to investigate whether ICA prevents bone loss by acting on BMSCs via affecting the level of autophagy after ovariectomy (OVX). The BMSCs were extracted from BALB/c mice treated with ICA, chloroquine (CQ, an autophagy inhibitor) or ICA + CQ. The OVX mice were injected with ICA, CQ, or ICA + CQ for 1 month. We performed Alizarin Red staining and alkaline phosphatase staining to detect osteogenic differentiation of BMSCs. Micro-CT, hematoxylin and eosin staining, Oil Red O staining, and tartrate-resistant acid phosphatase staining were used to assess the bone mass, lipid droplets and osteoclasts in femurs. Autophagy activity in BMSCs from different groups was evaluated by Western blot analysis. The osteogenic differentiation of BMSCs from OVX-induced OP mice was decreased. Treatment with ICA reduced bone loss and formation of osteoclasts and increased osteogenic differentiation of BMSCs in vitro and vivo. In addition, autophagy was enhanced in BMSCs of OVX mice treated with ICA. Our results indicate that ICA prevents OVX-induced bone loss possibly by strengthening the osteogenic differentiation of BMSCs via increasing autophagic activity.     

Pulsed electromagnetic fields accelerate proliferation and osteogenic gene expression in human bone marrow mesenchymal stem cells during osteogenic differentiation

Osteogenesis is a complex series of events involving the differentiation of mesenchymal stem cells to generate new bone. In this study, we examined the effect of pulsed electromagnetic fields (PEMFs) on cell proliferation, alkaline phosphatase (ALP) activity, mineralization of the extracellular matrix, and gene expression in bone marrow mesenchymal stem cells (BMMSCs) during osteogenic differentiation. Exposure of BMMSCs to PEMFs increased cell proliferation by 29.6% compared to untreated cells at day 1 of differentiation. Semi‐quantitative RT‐PCR indicated that PEMFs significantly altered temporal expression of osteogenesis‐related genes, including a 2.7‐fold increase in expression of the key osteogenesis regulatory gene cbfa1, compared to untreated controls. In addition, exposure to PEMFs significantly increased ALP expression during the early stages of osteogenesis and substantially enhanced mineralization near the midpoint of osteogenesis. These results suggest that PEMFs enhance early cell proliferation in BMMSC‐mediated osteogenesis, and accelerate the osteogenesis. Bioelectromagnetics 31:209–219, 2010. © 2009 Wiley‐Liss, Inc.     

Watching osteogenesis: life monitoring of osteogenic differentiation using an osteocalcin reporter

Human bone marrow-derived mesenchymal stem cells have the potential to differentiate into several cell types such as osteoblasts, chondrocytes, and adipocytes. When cultured under appropriate medium conditions stem cells can be directed toward the osteoblast lineage in vitro. Progression of osteogenic differentiation is accompanied by changes in the expression pattern of several marker proteins including bone-specific alkaline phosphatase (bALP), collagen I (Col I), and osteocalcin (OC) and can be analyzed by well-established methods like immunohistochemical staining and quantitative RT-PCR. Furthermore, expression of fluorescent protein driven by an osteogenesis promoter facilitates online monitoring of proceeding osteogenic differentiation in transiently transfected human bone marrow-derived cells. In the present study we established a new double reporter gene construct comprising OC promoter-driven expression of green fluorescent protein and constitutive expression of red fluorescent protein-tagged histone H2B for transient transfection of primary human bone cells (HBCs). Osteogenic differentiation of transiently transfected cells was visualized by fluorescence microscopy. Immunohistochemical analysis and RT-PCR confirmed the progression into the osteo-specific lineage of transfected cells. Transfection efficiency was determined by fluorescence-activated cell sorting (FACS).     

不同强度静电磁场对体外培养骨髓间充质干细胞增殖与分化的影响

本实验研究不同强度静电磁场对体外培养大鼠骨髓间充质干细胞增殖与分化作用. 体外分离培养大鼠骨髓间充质干细胞,传代后随机分为6组,分别用强度为0（对照组）、0.9、1.2、1.5、1.8和2.1 mT的静电磁场处理,每d每次处理30 min. 在磁场处理后的9~10 d ,骨髓间充质干细胞开始出现钙化小颗粒. 0.9 mT组抑制骨髓间充质干细胞增殖,1.5到2.1mT组促进骨髓间充质干细胞增殖. 在磁场处理后的12 d和15 d ,1.5和1.8 mT组极显著地增加了碱性磷酸酶(AKP)活性. 采用AKP组织化学染色和钙化结节染色对骨髓间充质干细胞成骨性分化进行鉴定,AKP组织化学染色和钙化结节染色都呈现了极强的阳性结果,尤以1.5 mT和1.8 mT阳性染色面积最大. 在SEMFs处理后的48 h 和96 h ,1.5 mT和1.8 mT组胶原I(collagen-Ⅰ)和骨形态发生蛋白2(bone morphogenetic protein-2, Bmp-2) 基因表达水平显著高于对照组.在SEMFs处理后的12 d, BMP-2蛋白表达量高于对照组. 研究表明,0.9 mT 组抑制骨髓间充质干细胞增殖,1.5 mT到2.1 mT组不同强度静电磁场促进体外培养骨髓间充质干细胞的增殖. 磁场组能促进骨髓间充质干细胞成骨性分化,其中尤以1.5 mT和1.8 mT组促进大鼠骨髓间充质干细胞分化作用效果最为明显.     

Uric Acid Promotes Osteogenic Differentiation and Inhibits Adipogenic Differentiation of Human Bone Mesenchymal Stem Cells

To investigate the effect of uric acid on the osteogenic and adipogenic differentiation of human bone mesenchymal stem cells (hBMSCs). The hBMSCs were isolated from bone marrow of six healthy donors. Cell morphology was observed by microscopy and cell surface markers (CD44 and CD34) of hBMSCs were analyzed by immunofluorescence. Cell morphology and immunofluorescence analysis showed that hBMSCs were successfully isolated from bone marrow. The number of hBMSCs in uric acid groups was higher than that in the control group on day 3, 4, and 5. Alizarin red staining showed that number of calcium nodules in uric acid groups was more than that of the control group. Oil red‐O staining showed that the number of red fat vacuoles decreased with the increased concentration of uric acid. In summary, uric acid could promote the proliferation and osteogenic differentiation of hBMSCs while inhibit adipogenic differentiation of hBMSCs.