成骨细胞与诱导剂对骨髓基质干细胞的增殖与成骨分化的影响

目的探索一种新的骨髓基质干细胞(marrow stromal stem cells,MSCs)增殖与成骨分化的体外诱导培养体系. 方法乳大鼠颅骨来源的第3代成骨细胞与诱导剂(1 nmol/L地塞米松、10 mmol/L β-甘油磷酸钠、50μg/ml抗坏血酸)对大鼠股骨、胫骨来源的MSCs生长的影响.于8块24孔板上培养MSCs,每孔接种5×104个第3代MSCs.按培养成分不同分为4组,每组2块.DMEM培养为对照组;诱导剂培养为诱导剂组;成骨细胞培养为成骨细胞组;联合使用成骨细胞与诱导剂培养为联合诱导组.计数诱导1～8 d各组MSCs的数量并绘制细胞生长曲线,检测诱导10 d的MSCs的碱性磷酸酶活性,采用RT PCR检测诱导2周时MSCs骨钙素mRNA的表达水平.结果原代及传代MSCs形态正常.细胞生长曲线示MSCs数量均随时间延长增加.成骨细胞组增殖最快,诱导剂组增殖最慢,5～8 d成骨细胞组及诱导剂组细胞数量与对照组比较,差异有统计学意义(P＜0.05).联合诱导组碱性磷酸酶活性为2.01±0.56 U与对照组0.68±0.14 U、诱导剂组1.27±0.43 U及成骨细胞组0.77±0.19 U比较,差异均有统计学意义(P＜0.05).对照组不表达骨钙素mRNA,诱导剂组为0.783±0.094、联合诱导组为0.814±0.071与成骨细胞组0.302±0.026比较,差异均有统计学意义(P＜0.05).结论联合使用成骨细胞和诱导剂诱导MSCs,不影响MSCs的正常增殖而促进MSCs的成骨分化,诱导效果较好,可望成为一种新的骨组织工程种子细胞的体外培养体系.     

氯化锂体外诱导人脐血间充质干细胞向神经细胞分化的实验研究

目的 探讨氯化锂体外诱导人脐血间充质干细胞(MSCs)向神经细胞分化的可行性.方法 无菌条件下收集正常足月儿的脐带血,肝素抗凝,密度梯度离心法分离人脐血单个核细胞,贴壁法纯化,用含15%FBS的低糖DMEM培养基进行扩增培养,流式细胞仪检测表面抗原.取3代的脐血MSCs进行诱导,A组:用含15%FBS和20 ng/ml bFGF的DMEM完全培养基预诱导24 h,3 mol/L LiCI的DMEM培养基继续诱导6 d:B组:含3 mol/L LiCI的DMEM培养基诱导7 d;C组:含15%FBS的DMEM培养基正常培养7 d.光镜下观察细胞形态,用免疫组化技术检测细胞NSE、MAP2及GFAP的表达.结果 A组与B组诱导3 d后细胞即出现形态学上的改变,细胞变成不规则形,立体感增强,从胞体伸出突起.免疫组织化学和免疫荧光方法鉴定显示,诱导后的细胞能表达神经元特异性标志NSE和MAP2,阳性表达率A组[分别为(73.6±7.8)%,(75.5±8.5)%]明显高于B组[分别为(31.0±4.3)%、(33.5±5.O)%],而星形胶质细胞特异性标志GFAP阳性细胞较少,A、B、C三组阳性表达率分别为(4.7 ±3.3)%、(5.1±4.6)%、(8.5±3.2)%.结论 LiCI联合生长因子bFGF体外可诱导人脐血MSCs分化为神经元样细胞.     

亚砷酸诱导骨髓基质干细胞向神经细胞的分化作用

目的 研究亚砷酸体外诱导骨髓基质干细胞（MSCs）向神经细胞分化的作用。方法 应用亚砷酸诱导体外培养的人胚胎和成年小鼠MSCs，观察诱导过程中的形态学变化；应用抗Nestin、抗MAP2、抗βⅢ-tubulin、抗磷脂碱性蛋白（MBP）及抗胶质纤维酸性蛋白（GFAP）抗体进行免疫细胞化学染色，逆转录-聚合酶链反应（RT-PCR）检测mRNA表达，以2-巯基乙醇（BME）作为对照。结果 经亚砷酸和BME诱导后，MSCs均表现为神经元细胞的形态特征。亚砷酸诱导组细胞形态变化较BME诱导组出现晚，且死亡率远低于后者。免疫细胞化学示Nestin、MAP2和βⅢ-tubulin阳性表达，MBP及GFAP为阴性表达。RT-PCR可见Nestin、MAP2、β-actin和βⅢ-tubulinmRNA阳性表达。结论 亚砷酸和BME均可在体外诱导人胚胎和成年小鼠MSCs向神经细胞分化，但亚砷酸诱导更为缓和。     

地塞米松和1，25(OH)2D3对体外人骨髓基质细胞成骨及成脂分化的影响

目的 观察地塞米松（Dex）和1，25（OH）2D3（D3）对骨髓基质细胞（MSCs）成骨及成脂分化的影响。方法 以离心法分离培养人MSCs，以10^-7mol／LDex和，或10^-8mol／Ll，25（OH）2D3作为分化诱导剂对细胞进行干预，分别用细胞碱性磷酸酶（ALP）染液试剂盒及苏丹Ⅲ染液对成骨细胞和脂肪细胞进行组织化学染色，计数；使用RT-PCR技术在转录水平检测成骨细胞标记物骨桥蛋白（OPN）及脂肪细胞标记物过氧化酶体增殖激活受体72（PPARγ2）mRNA的表达。结果细胞染色结果表明各干预组ALP^＋细胞百分比均较对照组增加，与对照组相比有显著性差异（P〈0．05），苏丹Ⅲ^＋细胞百分比Dex组较对照组增多，耽组较对照组减少，差异有显著性（P〈0．05），Dex＋D3组较Dex组苏丹Ⅲ^＋细胞数明显减少，两者相比差异有显著性（P〈0．05）；OPNmRNA及PPARγ2mRNA表达未在对照组测得，Dex诱导了OPNmRNA及PPARγ2mRNA表达，1，25（OH）2D3诱导OPNmRNA表达，并抑制Dex诱导的PPARγ2mRNA的表达。结论 Dex促进MSCs的成骨分化及成脂分化，1，25（OH），D，促进MSCs的成骨分化的同时抑制其成脂分化，与Dex合用抑制Dex成脂分化作用，强化了其成骨分化作用，反映了成骨细胞与脂肪细胞间存在的反变关系，表明两者来源于同一前体细胞的可能性。     

Hey1表达对BMP-9诱导下C3H10T1/2细胞的成骨分化及增殖影响

目的探讨Notch信号通路重要靶点Hey1表达水平改变对BMP-9诱导C3H10T1/2细胞成骨分化与增殖的影响。方法构建过表达Hey1慢病毒LV-Hey1、抑制Hey1表达慢病毒LV-sh Hey1,分别感染C3H10T1/2细胞干预Hey1表达水平,以LV-Blank(空质粒)感染C3H10T1/2细胞作为对照;以荧光显微镜对慢病毒感染效果、实时荧光定量PCR以及Western blot对Hey1表达水平进行验证,筛选不同Hey1表达水平的稳定细胞系。用含BMP-9的条件培养基诱导不同Hey1表达水平的C3H10T1/2细胞(分别为BMP-9+C3H10T1/2组、BMP-9+C3H10T1/2-Hey1组、BMP-9+C3H10T1/2-sh Hey1组),以正常培养基培养的细胞作为对照(C3H10T1/2组、C3H10T1/2-Blank组)。培养后48 h,实时荧光定量PCR及Western blot测定成骨分化相关转录因子Runx2、骨桥蛋白、骨钙素m RNA及蛋白表达水平;4、5、6、7 d行MTT检测及4、5、10 d行流式细胞仪测定细胞增殖能力;4、7 d时ELISA测定细胞ALP表达水平并行染色观察。结果成功建立不同Hey1表达水平稳定细胞系。成骨方面,各时间点与BMP-9+C3H10T1/2组比较,BMP-9诱导下Hey1过表达的BMP-9+C3H10T1/2-Hey1组细胞Runx2、骨桥蛋白、骨钙素m RNA及蛋白表达水平以及成骨分化标志物ALP含量均显著增加(P0.05),抑制Hey1表达的BMP-9+C3H10T1/2-sh Hey1组细胞以上指标均显著降低(P0.05)。对细胞增殖活力影响方面,与BMP-9+C3H10T1/2组比较,BMP-9+C3H10T1/2-Hey1组MTT检测吸光度(A)值及细胞G2+S期百分比均提高(P0.05);而抑制Hey1表达BMP-9+C3H10T1/2-sh Hey1组以上指标均降低(P0.05)。结论 Hey1表达是BMP-9诱导C3H10T1/2细胞成骨分化重要环节,同时影响细胞早期增殖。     

大鼠脂肪干细胞体外诱导为神经元样细胞的研究

目的 建立将大鼠脂肪干细胞体外诱导分化为神经元样细胞的方法.方法 取SD大鼠腹股沟处的皮下脂肪,分离出脂肪干细胞并培养传代.使用诱导剂IBMX诱导ADSCs向神经元样细胞分化,检测神经前体细胞标志Nestin和神经元标志NF200、MAP2,以明确分化结果,而且榆测Nestin在诱导过程中的表达阳性率的变化情况,采用SPSS11.0软件进行统计学分析.结果 从大鼠脂肪组织中分离出脂肪干细胞,经诱导剂IBMX诱导后,ADSCs表现出神经无样细胞形态,大部分细胞表达nestin,少部分细胞表达MAP2和NF200,随着诱导的进行,nestin的表达是升高的.结论 成功地建立了一种将大鼠脂肪干细胞体外诱导分化为神经元样细胞的方法,ADSCs有希望成为治疗神经性勃起功能障碍的、理想的组织工程种子细胞.     

胚胎源脊髓组织诱导骨髓基质干细胞向神经元样细胞的分化

目的体外诱导大鼠骨髓基质干细胞（BMSC）分化为神经元样细胞。方法采用Percoll（密度：1．073g／ml）梯度分离液，离心分离鼠BMSC，体外培养，提取大鼠胚胎脊髓组织匀浆诱导BMSC分化为神经元样细胞。形态学观察及免疫组织化学鉴定神经元烯醇化酶（NSE）、神经丝蛋白（NF-200）、胶质纤维酸性蛋白（GFAP）的表达。结果大鼠骨髓基质干细胞在诱导后细胞形态变化，突起交织；免疫组织化学发现分化细胞NSE、NF-200表达阳性率分别为（68．0±1．7）％，（76．2±2．9）％，少数GFAP阳性。结论胚胎脊髓组织匀浆可诱导骨髓基质干细胞分化为神经元样细胞。     

人嗅鞘细胞与骨髓间充质干细胞体外共培养的实验研究

[目的]通过体外共培养观察人嗅鞘细胞(OECs)对骨髓间充质干细胞(MSCs)增殖分化的影响.[方法]取5个月以上引产胎儿嗅球及骨髓,分离培养及鉴定OECs及MSCs,携带绿色荧光蛋白(GFP)基因的腺相关病毒转染标记OECs,双苯亚甲胺荧光染料标记MSCs,将两种细胞按1∶1比例进行共培养,MSCs单独培养组为阴性对照组,免疫细胞化学方法检测MSCs表达巢蛋白(nestin)、神经元特异性核蛋白(NeuN)、神经元特异性烯醇化酶(NSE)、神经丝蛋白(NF-M)、胶质纤维酸性蛋白(GFAP)情况.[结果]MOI值为1×106时OECs表达GFP阳性率为84.89％,对细胞生长活性无明显影响.共培养时两种细胞生长良好,共培养7d未见形态学改变,经复方丹参注射液诱导后部分MSCs呈现神经元样改变,表达nestin、NSE、NeuN、NF-M、GFAP特异性标志,且共培养组的分化率明显高于单独MSCs培养组,有显著性差异.[结论]OECs可通过分泌可溶性物质及细胞之间的相互作用启动MSCs分化程序,提高MSCs向神经细胞分化率.     

GSB中药血清对rMSCs定向诱导分化为成骨细胞的影响

目的观察GSB中药血清对大鼠MSCs定向诱导分化成骨的影响。方法将培养的rMSCs分为对照组（C组）[含10%胎牛血清,100U/ml青霉素和100μg/ml链霉素的完全培养液]、诱导组（O组）[完全培养液,加诱导培养液（0.1μmol/L地塞米松、10mmol/Lβ-甘油磷酸钠及50μg/ml维生素C）,加20%空白血清]和含药血清诱导组（G组）[完全培养液加诱导培养液诱导培养液中加入20%含药血清）。显微镜下观察细胞形态变化,生化法测定上清中Ca^2＋浓度,Gomori改良钙钴法进行ALP染色,Von Kossa法进行矿化结节染色,RT-PCR法测定Ⅰ型胶原（COLL1）和脂蛋白脂酶（LPL）的表达,放免法测定上清中骨钙素含量。结果O组和G组在加入诱导培养液3-4天后梭形细胞比例减少,细胞变形成多角形、乃至方形,部分区域细胞成多层生长;改良Gomori钙钻法碱性磷酸酶染色阳性细胞,Von Kassa染色发现钙盐沉积;培养9d后细胞Ca^2＋浓度开始升高,并随时间持续显著增长,且G组明显高于O组。自第15d后,O组和G组细胞ALP活性随时间延长而明显增高,且G组显著高于O组;培养的第14d,G组骨钙素分泌量明显高于O组。成骨诱导剂作用MSCs12d后,COLLⅠ mRNA表达阳性,LPL mRNA表达阴性,且G组比O组COLLⅠ mRNA表达更强。结论补肾填精中药GSB促进骨钙素分泌、增强ALP活性、促钙盐沉积,具有增强成骨诱导剂诱导rMSCs向成骨细胞分化,并促进成骨细胞成熟作用。     

shRNA干扰KAP-1基因表达对胰腺癌肿瘤干细胞自我更新的影响

目的 研究KAP-1对胰腺癌肿瘤干细胞自我更新能力的影响.方法 采用免疫组织化学方法检测14例胰腺癌组织标本和配对癌旁组织标本KAP-1蛋白的表达情况.PCR扩增KAP-1 shRNA干扰序列,克隆至pGC-LV慢病毒表达载体;双酶切及测序鉴定正确后进行慢病毒包装与滴度检测.构建成功后感染人胰腺癌细胞株Panc-1细胞48 h后,通过Western blot实验和RT-qPCR实验检测KAP-1的表达量以及该细胞系相关EMT标志蛋白波形蛋白的表达.采用悬浮法培养人胰腺癌Panc-1细胞生成肿瘤干细胞球,通过测定初代以及次代肿瘤干细胞球的成球直径和数量判断KAP-1基因敲减对肿瘤干细胞球成球能力及自我更新能力的影响.结果 在14例胰腺癌组织标本和癌旁组织标本的免疫组织化学检测中,胰腺癌组织标本KAP-1阳性数为13例(P=0.002).构建的慢病毒载体感染细胞48 h后,在倒置荧光显微镜下观察可见绿色荧光.RT-qPCR实验显示感染KAP-1 RNA干扰慢病毒载体的Panc-1细胞KAP-1及EMT标志蛋白波形蛋白的表达量较未感染病毒细胞以及感染空载体细胞显著增高.KAP-1基因敲低表达的人胰腺癌Panc-1肿瘤干细胞球的初代以及次代的成球直径相较于转染空载体的Panc-1肿瘤干细胞球发生明显减小,在成球数量上也明显减少.结论 KAP-1在胰腺癌组织中存在表达,且与正常组织表达量具有明显差异.构建了高效稳定表达KAP-1的RNA干扰慢病毒转染系统.KAP-1转录因子表达量降低可以减弱人类胰腺癌细胞Panc-1细胞系生成干细胞球的自我更新能力.其机制可能与敲低KAP-1表达影响波形蛋白下调有关.     

Vascular Smooth Muscle Cell Apoptosis Promotes Transplant Arteriosclerosis Through Inducing the Production of SDF‐1α

Transplant arteriosclerosis is a leading cause of late allograft loss. Medial smooth muscle cell (SMC) apoptosis is considered to be an important event in transplant arteriosclerosis. However, the precise contribution of medial SMC apoptosis to transplant arteriosclerosis and the underlying mechanisms remain unclear. We transferred wild‐type p53 to induce apoptosis of cultured SMCs. We found that apoptosis induces the production of SDF‐1α from apoptotic and neighboring viable cells, resulting in increased SDF‐1α in the culture media. Conditioned media from Ltv‐p53‐transferred SMCs activated PI3K/Akt/mTOR and MAPK/Erk signaling in a SDF‐1α‐dependent manner and thereby promoted mesenchymal stem cell (MSC) migration and proliferation. In a rat aorta transplantation model, lentivirus‐mediated BclxL transfer selectively inhibits medial SMC apoptosis in aortic allografts, resulting in a remarkable decrease of SDF‐1α both in allograft media and in blood plasma, associated with diminished recruitment of CD90⁺CD105⁺ double‐positive cells and impaired neointimal formation. Systemic administration of rapamycin or PD98059 also attenuated MSC recruitment and neointimal formation in the aortic allografts. These results suggest that medial SMC apoptosis is critical for the development of transplant arteriosclerosis through inducing SDF‐1α production and that MSC recruitment represents a major component of vascular remodeling, constituting a relevant target and mechanism for therapeutic interventions.     

Delta-like 1 (Dlk-1), a novel marker of prostate basal and candidate epithelial stem cells, is downregulated by notch signalling in intermediate/transit amplifying cells of the human prostate

Background

There is a lack of understanding of the processes that regulate differentiation in the prostate.

Objective

To determine localisation, activity, and regulation of cytodifferentiation-modulatory proteins in the human adult prostate.

Design, Settings, and Participants

Eighteen volunteering patients with organ-confined prostate cancer were prospectively enrolled at a single university hospital.

Intervention

All patients underwent radical prostatectomy, and normal/benign tissue was excised and obtained from the transition zone.

Measurements

Expression and activity of Notch-protein family members, including the Notch-homologous protein Delta-like 1 (Dlk-1/Pref1), were investigated immunohistochemically in normal/benign tissue and explant cultures. The effect of the Notch inhibitor L-685,458 on Dlk-1 expression and cell number was investigated in primary cell cultures, and data were analysed with Student t test.

Results and Limitations

Mature luminal cells were found to co-express Notch-1 and its ligand Jagged1, but epithelia in normal/benign tissue showed no active Notch signalling. The basal cell layer, rare candidate epithelial stem cells, and a subpopulation of neuroendocrine cells expressed the differentiation protein Dlk-1. In explant cultures, luminal cells and Jagged1 expression were lost, whereas intermediate cells downregulated Dlk-1 concomitant with Notch-1 upregulation and activation. Notch inhibition in primary cell cultures led to lower cell densities (p < 0.001) and suppressed downregulation of Dlk-1. This is a small study; current results need to be confirmed in larger investigations.

Conclusions

We demonstrate that Notch-1 is upregulated in differentiation of prostate epithelia, and that the novel prostate progenitor marker Dlk-1 is downregulated by Notch signalling in intermediate cells. The identification of Dlk-1–expressing candidate stem and neuroendocrine cells suggests a hierarchical relationship.     

Functional endothelin 1 receptors on human glomerular podocytes and mesangial cells.

To determine if endothelin 1 (Et1) receptors are present in human glomeruli, and which glomerular cells possess these receptors, 125I Et1 binding to isolated glomeruli and cultured glomerular mesangial and epithelial cells was studied. The latter were identified as podocytes. We demonstrated that Et1 binds specifically and reversibly to isolated human glomeruli and to cultured glomerular mesangial and epithelial cells. Scatchard analysis of competitive inhibition of 125I Et1 binding gave the following results (m +/- SEM, n = 3): isolated glomeruli, Kd = 4.2 +/- 2.1 x 10(-10) M, Bmax = 8.1 +/- 1.2 x 10(10) sites/mg protein; mesangial cells, Kd = 5.2 +/- 1.5 x 10(-10) M, Bmax = 1.87 +/- 0.49 x 10(4) sites/cell; epithelial cells, Kd = 7.2 +/- 1.5 x 10(-10) M, Bmax = 2.46 +/- 0.15 x 10(4) sites/cell. These receptors seem to be functional, since in both mesangial and epithelial cells Et1 induces a rapid and transient increase in intracellular [Ca2+]i. All these results indicate that Et1 may regulate glomerular filtration rate through an autocrine-paracrine pathway on mesangial cells and on podocytes.     

Spontaneous release of interleukin-1 (IL-1) from medullary mononuclear cells of pagetic subjects

Summary The Authors examined interleukin 1 (IL-1) secretion from the peripheral and medullary mononuclear cells, obtained with sequential separation on Ficoll-Hypaque and 45% Percoll gradient, in 6 pagetic subjects and 6 normal controls. Both peripheral and medullary cells from pagetic subjects showed a significantly greater IL-1 production after stimulation with lipopolyshaccarides (LPS); moreover, we observed a spontaneous IL-1 release from medullary cells in pagetic subjects but not in normal controls. These findings suggest a possible role of IL-1 in the elevated bone turnover of Paget's disease of bone.     

HT-29肠癌细胞中E-selectin、Integrin β1及ICAM-1表达水平

目的：探讨HT-29肠癌细胞、正常肠上皮细胞及ECV-304血管内皮细胞中E—selectin、Integrin β1及ICAM-1的表达状态。方法：采用Nothern Blotting方法检测HT-29肠癌细胞、正常肠上皮细胞和ECV-304血管内皮细胞中E—selectin、Integrin β1及ICAM-1 mRNA表达水平，采用EIJSA法定量分析其表达含量。结果：HT-29肠癌细胞、正常肠上皮细胞和ECV-304血管内皮细胞均有E—selectin、Integrin81及ICAM-1基因表达。EIJSA定量测定3个粘附分子表达水平，HT-29肠癌细胞均高于正常肠上皮细胞和ECV-304血管内皮细胞，分别存在显著性差异（P〈0．05）。结论：E—selectin、Integrin β1、ICAM-1可能与肿瘤细胞转移有关。     

Heme Oxygenase-1 Modulates Mesangial Cell Proliferation by P21Waf1 Upregulation

Mesangial cell (MC) proliferation is a hallmark of many progressive renal diseases. Heme oxygenase-1 (HO-1) has been shown to have an anti-proliferative effect on vascular smooth muscle cells. In the present study, we evaluated the role of HO-1 on MC proliferation and the involved molecular mechanism. Both epidermal growth factor (EGF) and hepatocyte growth factor (HGF) not only enhanced mesangial cell HO-1 expression but also stimulated proliferation of MCs. Interestingly, inhibition of HO-1 induction (by zinc protoporphyrin, ZnP) was associated with an accelerated mitogenic response to EGF and HGF in MCs. Induction of HO-1 was associated with enhanced mesangial cell p21 expression. On the other hand, hemoglobin and ZnP inhibited mesangial cell p21 expression. It appears that the effect of HO-1 on MC growth may be mediated through upregulation of p21 expression.     

Blockade of 4-1BB (CD137)/4-1BB ligand interactions increases allograft survival

We investigated the role of 4-1BB, a T cell co-stimulatory molecule, in alloimmune responses. In vivo mixed lymphocyte reactions showed that 4-1BB was preferentially expressed on actively dividing CD4⁺ and CD8⁺ T cells. Furthermore, following alloantigen challenge, the draining lymph nodes contained subpopulations of 4-1BB-expressing CD4⁺ and CD8⁺ T cells. 4-1BB-deficient C57BL/6 mice showed a delayed rejection of cardiac transplants mismatched for the major histocompatibility complex. Longer transplant survival was induced by blockade of 4-1BB/4-1BB ligand (4-1BBL) interactions using an anti-4-1BBL monoclonal antibody. Histological analysis showed that prolonged transplant survival in the 4-1BB-deficient and anti-4-1BBL-treated mice correlated with reduced lymphocytic infiltration and vasculitis in the donor heart tissue. Taken together, our data suggest that blockade of 4-1BB/4-1BBL interactions inhibited the expansion of alloreactive T cells and reduced CTL activity against host alloantigen, which in turn resulted in the prolongation of allograft survival. Blockade of the 4-1BB co-stimulatory pathway may be useful for preventing allograft rejection.H.R. Cho and B. Kwon contributed equally to this work.     

pDC1抑制T细胞增殖的实验研究

目的　研究 pDC1体外对T细胞增殖的抑制作用。方法　采集健康恒河猴外周血 ,用Ficoll Hypaque梯度离心法和三色流式细胞仪分离 pDC1,经混合淋巴细胞培养 (MLR)研究其免疫调整功能。结果　新鲜分离的 pDC1具有较弱的刺激T细胞增殖能力 ;在经CD40L培养后 pDC1即成熟DC1成为有效的T细胞刺激增殖者。结论　本实验用MLR方法成功地研究了恒河猴外周血pDC1体外抑制T细胞增殖的作用 ,为阐明pDC1诱导免疫耐受的作用机制奠定了基础。     

Prostaglandin E1 (PGE1) attenuates vasoconstriction induced by PGE2, PGD2 and phorbol myristate acetate in the perfused rat liver

It has been shown that prostaglandins (PGs) produced by Kupffer and endothelial cells play an important role in mediating physiological responses to various immunological stimuli. We studied the effect of prostaglandin E₁ (PGE₁) on the hemodynamic and metabolic changes induced by prostaglandin E₂ (PGE₂), D₂ (PGD₂) and phorbol 12-myristate 13-acetate (PMA), a potent inducer of PGs in the isolated rat liver perfused with Krebs-Ringer-bicarbonate (KRB) solution at a constant pressure of 12cmH₂O. The liver was taken from overnight-fasted male Sprague-Dawley rats weighing 260 to 310g. Both PGE₂ and PGD₂ significantly decreased hepatic flow when their initial concentration was elevated to micromolar range. Although 1 × 10^–6M of PGE₁ did not have a major effect on hepatic flow, it significantly attenuated the declines of hepatic flow produced by 4 × 10^–6M of PGE₂ and PGD₂. However, none of PGs tested influenced glucose and lactate concentrations in the medium. Continuous infusion of PGE₁ into the medium at a rate of 5µg·min^–1 significantly diminished the decreases in hepatic flow and oxygen consumption induced by 2 × 10^–8M of PMA. These results suggest that administration of PGE₁ may preserve hepatic blood flow by modifying the intrahepatic regulatory mechanism involving the activation of Kupffer and endothelial cells.(Inaba H, Araki M, Numai T, et al.: Prostaglandin E₁ (PGE₁) attenuates vasoconstriction induced by PGE₂, PGD₂ and phorbol myristate acetate in the perfused rat liver. J Anesth 7: 56–65, 1993)