富血小板血浆与洗涤血小板对人牙髓细胞矿化的作用**○

背景：此前课题组的研究表明富血小板血浆和洗涤血小板在一定浓度范围内均可促进人牙髓细胞的增殖。 目的：进一步观察不同浓度富血小板血浆和洗涤血小板对人牙髓细胞矿化的作用效果。 方法：实验使用健康志愿者正畸拔除牙齿内牙髓培养的4~6代牙髓细胞。将由该志愿者采集的静脉血制备富血小板血浆和洗涤血小板作用于牙髓细胞,使用碱性磷酸酶及蛋白定量试剂盒测定矿化诱导7 d后牙髓细胞的碱性磷酸酶活性,并通过茜素红染色观测牙髓细胞经矿化诱导10 d及20 d后的矿化结节形成情况。 结果与结论：10%~30%的洗涤血小板与富血小板血浆均明显提高了牙髓细胞碱性磷酸酶活性,其中,以20%浓度尤为明显;10%~30%的洗涤血小板与富血小板血浆均明显促进了矿化诱导后10 d的牙髓细胞矿化结节形成,其中,10%浓度在矿化诱导后20 d促进牙髓细胞形成的矿化结节最大。但相同浓度的洗涤血小板与富血小板血浆之间在作用效果上没有明显差异。     

前列腺素E2合成酶研究进展

前列腺素E2合成酶(PGES)是前列腺素E2合成途径中的末端合成酶,目前发现至少存在3种PGES胞质PGE2合成酶(cPGES)、膜相关PGE2合成酶1(mPGES1)和膜相关PGE2合成酶2(mPGES2).cPGES属结构型酶,广泛地在各种正常细胞和组织表达,主要与COX-1协同合成PGE2维持细胞内环境稳定;mPGES1是一种诱导酶,和COX-2一起参与延迟的PGE2生成,参与多种病理生理过程;mPGES2是最近新发现的一种PGE2合成酶,结构和功能还有待研究.而mPGES1有可能成为治疗和预防炎症、骨质疏松甚至癌症药物理想的新靶点.     

中药促成骨细胞增殖和分化的机制与作用

背景：中药促进成骨细胞增殖和分化的效果已经得到肯定,其在细胞分子水平的药理机制研究取得了很大进展。 目的：对国内外应用中药诱导成骨细胞增殖和分化的药理机制研究进展作一综述。 方法：应用计算机检索CNKI,Pubmed和sciencedirect数据库中2001-01/2010-12关于中药促进成骨细胞增殖和分化机制研究的文章,在标题和摘要中以“中药,成骨细胞,增殖,分化,机制”或“Chinese herbs,osteoblast,proliferation,differentiation, mechanism”为检索词进行检索。初检得到176篇文献,最终选择30篇文献进行综述。 结果与结论：中药通过对成骨细胞基因、信号通路、细胞因子和OPG/RANK/RANKL系统的调控,以及类雌激素样作用促进成骨细胞增殖和分化,其作用机制明确,将中药引入骨组织工程领域具有良好的发展前景。 关键词：中药;成骨细胞;增殖;分化;机制;组织工程 doi:10.3969/j.issn.1673-8225.2012.07.037     

前列腺素E2抑制T细胞活化的机制

机体在严重烧伤、创伤、败血症等情况下,T细胞免疫功能受到抑制.前列腺素E2是抑制T细胞免疫活化的重要炎性介质之一,它通过对T细胞活化途径中的信号转导分子的抑制作用,使T细胞处于免疫失活或无能状态,这种免疫调节作用,在机体处于应急状态下,发挥免疫保护作用.     

控释前列腺素E2栓剂与催产素引产效果评价

目的评价控释前列腺素E2（商品名：普贝生）栓剂引产的安全性及有效性。方法病例对照研究的方法,选择114例孕妇,其中54例采用小剂量催产素引产,60例采用普贝生,通过比较两组用药前后的宫颈Bishop评分、临产时间、第一产程时间、第二产程时间来评价其引产的有效性;通过比较两组间出现高张宫缩、过频宫缩、宫缩乏力、新生儿窒息率、胎儿窘迫发生率、剖宫产率及自然分娩率等因素来评价其引产的安全性。采用SPSS软件处理所得数据。结果普贝生组促宫颈成熟作用明显高于催产素组（显效率94.2%∶11.1%）;普贝生组临产时间（912±334分∶2309±1042分;）、第一产程时间（307±94分∶538±152）均明显短于催产素组;普贝生组剖宫产率明显低于催产素组（13.3%∶31.2%）,自然分娩率明显高于催产素组（86%∶55%）;宫缩乏力的发生率明显低于催产素组（22.2%∶6.6%）;普贝生组在高张宫缩、过频宫缩、新生儿窒息率、胎儿窘迫发生率方面与催产素组无显著差异。结论与小剂量催产素引产相比较,普贝生具有良好的促宫颈成熟作用,在足月引产的使用中是安全有效的。     

不同体积分数富血小板血浆与大鼠毛囊干细胞的增殖

背景：研究发现富血小板血浆在促进骨再生、软组织修复以及组织工程研究中种子细胞的增殖分化方面有着重要的作用。 目的：观察不同制备方法、不同体积分数富血小板血浆对体外培养大鼠毛囊干细胞增殖的影响。 方法：联合采用显微分离技术,两步酶法及差速贴壁法获取纯度较高、生长状态较好的第3代大鼠毛囊干细胞。采用2次离心法和3次离心法获取大鼠富血小板血浆,分别按1.0%,2.0%,4.0%不同浓度稀释于K-SFM培养基中,以加入含不同体积分数富血小板血浆培养基组为实验组,并以未加入富血小板血浆的培养基为对照。 结果与结论：联合采用显微分离技术,两步酶法及差速贴壁法能获取纯度较高的毛囊干细胞。培养前2 d各实验组与对照组的比较差异无显著性意义(P > 0.05),实验组加入富血小板血浆干预2 d后,毛囊干细胞出现较高的增殖活性,第4天开始进入生长对数期,细胞第5天即达到70%-80%汇合,培养六七天细胞进入平台期。高剂量富血小板血浆组对细胞增殖效果优于低剂量组,体积分数相同的情况下3次离心法制备所得富血小板血浆对毛囊干细胞增殖作用明显高于2次离心法,以加入3次离心法制备且体积分数为4.0%的富血小板血浆组毛囊干细胞增殖效果最明显。     

EP_2A体外可促进人CD34~+细胞归巢而不能促进其增殖

目的:探讨前列腺素E_2受体2激动剂(EP_2A)在体外对人CD34~+细胞的归巢与增殖作用。方法:收集健康供者经粒细胞集落刺激因子动员后的外周血,免疫磁珠法分选出人CD34~+细胞;同时收集健康供者动员前骨髓液,分离单个核细胞,并行骨髓间充质干细胞(BMMSC)培养。人CD34~+细胞和BMMSC经前列腺素E_2(阳性对照)、DMSO(阴性对照)、EP_2A和EP_2A+前列腺素E_2受体2拮抗剂(EP_2AA)处理后,对人CD34~+细胞用CCK-8法检测细胞活力,集落形成实验检测集落形成数目,流式细胞术检测G_2/M期细胞比例,Western blot检测细胞中survivin、β-catenin及CXC趋化因子受体4(CXCR4)的蛋白表达;ELISA法检测BMMSC中基质细胞衍生因子1α(SDF-1α)的含量。结果:EP_2A组与阴性对照组相比,人CD34~+细胞在细胞活力、集落形成数目、G_2/M期比例及survivin和β-catenin蛋白表达方面均无明显差别。但EP_2A组人CD34~+细胞CXCR4及BMMSC SDF-1α的表达均明显高于阴性对照组。结论:EP_2A体外可促进人CD34~+细胞归巢但不能促进其增殖。     

静磁场作用下大鼠牙槽骨中前列腺素E2变化的研究

目的：通过对大鼠在静磁场和非磁场作用下其牙槽骨的内源性前列腺素Ｅ２随时间变化的对比研究,了解在静磁场作用下,大鼠牙槽骨中前列腺素Ｅ２含量的时间变化性。方法：放射免疫法检测２０只加静磁场、２０只加非磁场和４只空白对照的大鼠牙槽骨中前列腺素Ｅ２的含量,探讨静磁场对大鼠牙槽骨的内源性前列腺素Ｅ２的变化的影响。结果：未受力时,大鼠的牙槽骨内即存在一定数量的前裂腺素Ｅ２。在静磁场作用下,牙槽骨的内源性前列腺     

BPH-1通过分泌前列腺素E2促进前列腺间质细胞芳香化酶的表达

目的：研究前列腺上皮细胞旁分泌对间质细胞芳香化酶表达的影响。方法：用前列腺上皮细胞系（BPH-1, LNCap, DU145, PC3）条件培养液（CM）处理间质细胞，用RT-qPCR和Western blotting检测芳香化酶表达水平。用RT-qPCR和ELISA检测上皮细胞系环氧合酶2（COX-2）的表达及其CM前列腺素E2(PGE2)浓度。用添加COX-2特异性抑制剂NS-398的培养液培养BPH-1，检测其CM和PGE2对间质细胞芳香化酶表达影响。结果：良性前列腺增生上皮细胞系BPH-1 CM能促进间质细胞芳香化酶mRNA和蛋白的表达，而前列腺癌细胞系PC3、DU-145和LNCap对芳香化酶的表达没有影响。BPH-1 COX-2 mRNA表达水平和PGE2分泌水平远高于其它癌细胞系。添加NS-398培养BPH-1的CM，其PGE2浓度明显降低。PGE2可明显诱导间质细胞芳香化酶的表达。结论：BPH-1通过分泌PGE2促进前列腺间质细胞芳香化酶的表达。     

胎牛血清外泌体对成骨细胞增殖的作用

背景:研究表明外泌体具有促进骨再生的能力,但从胎牛血清中提取的外泌体是否可以促进骨形成仍存在争议。目的:观察胎牛血清外泌体对成骨细胞增殖能力的影响,从而为临床治疗骨破坏提供新思路。方法:通过超速离心法从胎牛血清中提取外泌体,采用透射电子显微镜和Western blot法验证外泌体是否提取成功;然后用10 mg/L胎牛血清外泌体干预成骨前体细胞MC3T3-E1,通过CCK-8实验检测外泌体对成骨细胞增殖能力的影响,Western blot检测外泌体对成骨细胞骨形态发生蛋白2和骨桥蛋白表达的影响。以不含外泌体的胎牛血清培养的MC3T3-E1细胞为对照组。结果与结论:①胎牛血清外泌体具有典型的脂质双层膜结构,大小在30-150 nm之间,外泌体表面标记因子CD81表达呈阳性,而微囊表面标记物CD40表达呈阴性;②外泌体组的增殖能力明显高于对照组,差异有显著性意义(P<0.05);外泌体组成骨标志性因子骨形态发生蛋白2和骨桥蛋白的表达水平明显高于对照组,差异有显著性意义(P<0.05);③结果表明,胎牛血清外泌体对成骨细胞的增殖起促进作用,可为临床治疗骨破坏提供新思路。     

High-glucose-induced prostaglandin E(2) and peroxisome proliferator-activated receptor delta promote mouse embryonic stem cell proliferation

Peroxisome proliferator-activated receptor is a nuclear receptor that has been implicated in blastocyst implantation, cell cycle, and pathogenesis of diabetes. However, the signal cascades underlying this effect are largely unknown in embryo stem cells. This study examined whether or not there is an association between the reactive oxygen species-mediated prostaglandin E(2) (PGE(2))/peroxisome proliferator-activated receptor (PPAR) delta and the growth response to high glucose levels in mouse ESCs. A high concentration of glucose (25 mM) significantly increased the level of [3H]thymidine incorporation, the level of 5-bromo-2'-deoxyuridine incorporation, and the number of cells. Moreover, 25 mM glucose increased the intracellular reactive oxygen species, phosphorylation of the cytosolic phospholipase A(2) (cPLA(2)), and the release of [3H]arachidonic acid ([3H]AA). In addition, 25 mM glucose also increased the level of cyclooxygenase-2 (COX-2) protein expression, which stimulated the synthesis of PGE(2). Subsequently, high glucose-induced PGE(2) stimulated PPARdelta expression directly or through Akt phosphorylation indirectly through the E type prostaglandin receptor receptors. The PPARdelta antagonist inhibited the 25 mM glucose-induced DNA synthesis. Moreover, transfection with a pool of PPARdelta-specific small interfering RNA inhibited the 25 mM glucose-induced DNA synthesis and G1/S phase progression. Twenty-five millimolar glucose also increased the level of the cell cycle regulatory proteins (cyclin E/cyclin-dependent kinase [CDK] 2 and cyclin D1/CDK 4) and decreased p21(WAF1/Cip1) and p27(Kip1), which were blocked by the inhibition of the cPLA(2), COX-2, or PPARdelta pathways. In conclusion, high glucose promotes mouse ESC growth in part through the cPLA(2)-mediated PGE(2) synthesis and in part through PPARdelta pathways.     

The combined effect of prostaglandin E2 and interleukin 1 on interleukin 2 production and lymphocyte proliferation

In this study the combined effect of prostaglandin E2 (PGE2) and interleukin-1 (IL-1) on the proliferation of concanavalin A (Con A) stimulated mouse spleen lymphocytes was studied. IL-1 in concentrations ranging from 0.5 to 5.0 U/ml consistently and significantly enhanced Con A activity. However, to be effective, IL-1 needed to be added at the time of initiation of the culture. If added 24 h later, IL-1 failed to enhance the proliferative response. PGE2 at concentrations ranging from 0.1 to 5.0 ng/ml effectively inhibited or antagonized this enhancing effect of IL-1, with the majority of this IL-1 augmentation abrogated by 5.0 ng/ml PGE2. Unlike IL-1, PGE2 was as effective if added 24 h after initiation of the culture as if added simultaneously with IL-1. PGE2 was also found to markedly suppress the enhanced production of IL-2 resulting from the addition of IL-1 to Con A stimulated lymphocytes, however, the amount of IL-2 produced in the cultures containing both IL-1 and PGE2 was always greater than that produced in the cultures which contained only PGE2. This finding indicates that IL-1 could partially reverse or antagonize the suppressive effect of PGE2 on IL-2 production. In addition, PGE2 at concentrations of 1.0 and 5.0 ng/ml was also found to inhibit the proliferation of IL-2 stimulated cultured T lymphocytes, but by only about 15-20%. The addition of IL-1 to these cultured T cells neither altered the response of the culture T cells to IL-2 nor altered the sensitivity of these cells to PGE2.(ABSTRACT TRUNCATED AT 250 WORDS)     

Human monocyte heterogeneity: interleukin 1 and prostaglandin E2 production by separate subsets

Human peripheral blood monocytes were separated into four different subpopulations by means of a discontinuous bovine serum albumin gradient. Of the least dense population, 7% were present in fraction A, 11% in fraction B, 28% in fraction C and of the most dense, 34% were in fraction D. The rest (17%) of the recovered cells sedimented as a pellet, of which 95% were dead. The monocytes of fraction D (= greater than or equal to 1.075 kg/l) were major interleukin 1 (IL 1) producers and their presence enhanced immunoglobulin synthesis in vitro. Fraction C (= greater than or equal to 1.070 kg/l) were the major prostaglandin E2 (PGE2) producers and demonstrated suppressor activity on in vitro IgG and IgM synthesis. Fractions A and B had minimal production of either IL 1 or PGE2 and lesser effects on the IgG and IgM synthesis. These data demonstrate functional heterogeneity of peripheral blood monocytes with respect to production of both IL 1 and PGE2 as well as accessory cells for immunoglobulin synthesis.     

Interleukin-2 augmentation of interleukin-1 and prostaglandin E2 production

Some of the major side effects of interleukin-2 (IL-2) therapy in the treatment of malignancies may be related to increased interleukin-1 (IL-1) and/or prostaglandin E2 (PGE2) production. We examined the effect of recombinant (rIL-2) on the in vitro production of IL-1 beta and PGE2 by unstimulated and LPS-activated human blood mononuclear cells (PBMC). We also compared the effect of rIL-2 on IL-1 beta production by adherent and nonadherent blood mononuclear cell populations. Cultures of PBMC (5 x 10(6)/ml) were incubated for 24 hr in media only (control, 1,000 U/ml rIL-2, 2 micrograms/ml LPS, or both LPS and rIL-2. Supernatants obtained from these cultures were analyzed for levels of IL-1 beta and PGE2 by radioimmunoassays. The addition of rIL-2 caused an increase in IL-1 beta production in 13 of 13 control PBMC cultures and in 11 of 13 LPS-stimulated cultures, which were significant increases as determined by paired t tests. When PBMC were fractionated into plastic adherent and nonadherent populations, the rIL-2 induced increases in IL-1 beta production were more consistent in control (six of seven cases) and LPS (seven of seven cases) cultures of plastic nonadherent cells than in control (three of seven cases) and LPS (four of seven cases) cultures of plastic adherent cells. Recombinant IL-2 did not increase PGE2 production in control PBMC cultures (none of four cases), but did so in LPS-stimulated PBMC cultures (three of four cases]. These results suggest that rIL-2 may increase IL-1 production in vivo and thus possibly account for some of the side effects of this therapy.     

Characterization of prostaglandin E2 production by Candida albicans

Candida albicans produces lipid metabolites that are functionally similar to host prostaglandins. These studies, using mass spectrometry, demonstrate that C. albicans produces authentic prostaglandin E(2) (PGE(2)) from arachidonic acid. Maximal PGE(2) production was achieved at 37 degrees C in stationary-phase culture supernatants and in cell-free lysates generated from stationary-phase cells. Interestingly, PGE(2) production is inhibited by both nonspecific cyclooxygenase and lipoxygenase inhibitors but not by inhibitors specific for the cyclooxygenase 2 isoenzyme. The C. albicans genome does not possess a cyclooxygenase homolog; however, several genes that may play a role in prostaglandin production from C. albicans were investigated. It was found that a C. albicans fatty acid desaturase homolog (Ole2) and a multicopper oxidase homolog (Fet3) play roles in prostaglandin production, with ole2/ole2 and fet3/fet3 mutant strains exhibiting reduced PGE(2) levels compared with parent strains. This work demonstrates that the synthesis of PGE(2) in C. albicans proceeds via novel pathways.     

IL-10 inhibits prostaglandin E2 production by lipopolysaccharide-stimulated monocytes

Since IL-10 has recently been shown to exhibit plelotroplc effectson human monocytes, It was of interest to determine the effectof this cytoklne on prostaglandin E2 (PGEJ production by monocytes.Recomblnant IL-10 (rlL-10) did not significantly affect PGE₂production by lipopolysaccharide (LPS)-unstimulated monocytes,but efficiently inhibited PGE₂ production by LPS-stlmulatedmonocytes. The inhibition by rlL-10 was achieved in a dose-dependentmanner. Recombinant IL-4 also inhibited PGE₂ production at thesame degree as rlL-10. Viral IL-10 Inhibited PGE2 productionby monocytes in a similar fashion as did human rlL-10. Endogenouslyproduced IL-10 was also shown to inhibit PGE₂ production byLPS-stlmulated monocytes. Kinetic studies showed that the inhibitionby rlL-10 on PGE₂ production was observed at least 3 h afterLPS stimulation. Taken together, these results indicate thatIL-10 may play an important role in modulating immunologlcalresponses via down-regulation of PGE₂ production by monocytes.     

Lectins modulate prostaglandin E2 production by rat peritoneal macrophages

The effect of Aloctin A (Alo A), a lectin having anti-inflammatory activities, on prostaglandin (PG) E₂ production by activated rat peritoneal macrophages was compared with that of concanavalin A (Con A), wheat germ agglutinin (WGA), plsum sativum agglutinin (PSA) and soybean agglutinin (SBA). Alo A, WGA, Con A and PSA at 10 g per ml inhibited PG E₂ production. But SBA, even at a dose of 1 g per ml, stimulated PG E₂ production. The inhibition by Alo A treatment of the release of radioactivity from (³H)arachidonic acid-labeled macrophages and the stimulation of this release by SBA treatment were observed. The uptake of (⁵¹Cr)-labeled sheep red blood cells by the macrophage was inhibited by Alo A, Con A, and PSA, all at 10 g per ml and SBA at 1 g per ml, however, WGA at 10 g per ml stimulated the uptake of the sheep red blood cells. The mechanism of the anti-inflammatory properties of Alo A was discussed.To whom correspondence should be addressed.     

Hepatocyte modulation of Kupffer cell prostaglandin E2 production in vitro

It is likely that dynamic interactions between hepatocytes and Kupffer cells contribute to the responses of these cell types both under normal conditions and during sepsis. In this study, we examined the influences of hepatocytes on the concentration of the inflammatory mediator PGE2 in Kupffer cell cultures. Evidence to suggest that cultured rat hepatocytes both metabolize PGE2 and produce a substance that promotes LPS-stimulated Kupffer cell PGE2 biosynthesis include the following: 1) PGE2 levels in Kupffer cell: hepatocyte coculture were lower than the levels in Kupffer cell cultures early after LPS stimulation; 2) 36 h after LPS, coculture PGE2 levels exceeded the levels in Kupffer cell cultures despite the demonstrated capacity for hepatocytes to metabolize PGE2; 3) a transferable, non-dialyzable, and heat-unstable factor in hepatocyte supernatant promoted PGE2 production when added to Kupffer cells with LPS or after LPS; 4) there was no increased PGE2 synthesis when the hepatocyte supernatant was added without LPS or if hepatocyte supernatant was preincubated with the Kupffer cells for 6 or 18 h before LPS administration; 5) there was an inability of the hepatocyte factor to promote PGE2 production in response to other macrophage-activating agents, including calcium ionophore A23187 or phorphol myristate acetate; and 6) there was no increased cell replication or protein synthesis in the Kupffer cell cultures following hepatocyte supernatant incubation. The increased Kupffer cell PGE2 production by the hepatocyte supernatant was not due to contamination of the hepatocyte supernatant by endotoxin or PGE2. These in vitro results raise the possibility that hepatocytes have the capacity to modulate local PGE2 levels by two distinct mechanisms. Hepatocytes can metabolize PGE2 as well as release factor(s) which promote LPS-induced PGE2 production by Kupffer cells.     

Nitric oxide production by Leishmania-infected macrophages and modulation by prostaglandin E2

Nitric oxide (NO), produced by the nitric oxide synthase (iNOS) enzyme, is the most-important molecule responsible for the killing of Leishmania parasites by macrophages. In previous work we have demonstrated that, after activation with recombinant human interferon-γ and/or bacterial lipopolysaccharide, human macrophages infected with Leishmania infantum are able to produce nitric oxide and to express nitric oxide synthase. The arachidonate derivative prostaglandin E₂ has been shown to modulate various macrophage activities, and in particular nitric oxide production, sometimes with opposite effects, related to experimental conditions. In this work we have evaluated nitric oxide release and parasite killing by peripheral blood-derived L. infantum-infected human macrophages in vitro stimulated with lipopolysaccharide and simultaneously treated with prostaglandin E₂. Experiments were also performed in the presence of the nitric oxide synthase inhibitor l-N ^G monomethylarginine (l-NMMA) and of the cyclooxygenase inhibitor indomethacin. Nitric oxide release in supernatants of macrophage cultures was measured by the Griess reaction for nitrites. Parasite killing was microscopically evaluated by fluorescent dyes. Results demonstrated that macrophages stimulated with lipopolysaccharide and treated with prostaglandin E₂ exhibited increased nitric oxide producation and parasite killing, which were significantly reduced by either l-NMMA or indomethacin. In indomethacin-treated macrophages, nitric oxide production and leishmanicidal ability were partially restored by the addition of exogenous prostaglandin E₂. Taken together, these results indicate that prostaglandin E₂ may be involved in nitric oxide production, and possibly in the host-protective immune response against Leishmania. Moreover, the demonstration of a stimulatory role of prostaglandin E₂ on nitric oxide production induced by intracellular pathogens in humans is interesting in the light of a possible pharmacological regulation of nitric oxide by modulation of prostaglandin E₂ synthesis. Received: 27 March 2001 / Accepted: 24 August 2001