激活素A对小鼠巨噬细胞分泌IL-1β的影响

目的：探讨激活素A对小鼠腹腔巨噬细胞活性的调节作用及其机制。方法：免疫组化观察激活素ⅡA型受体（ActRⅡA）在巨噬细胞上的表达，ELISA法检测小鼠腹腔巨噬细胞培养上清中IL-1β分泌水平，采用RT-PCR检测小鼠腹腔巨噬细胞IL-1βmRNA、ActRⅡA mRNA及激活素受体相互作用蛋白2（ActRIP2）mRNA的表达。结果：激活素A可以促进原代培养小鼠腹腔巨噬细胞分泌IL-1β及IL-1β mRNA表达，并呈剂量依赖关系；激活素A对LPS活化的小鼠原代培养腹腔巨噬细胞分泌IL-1β及IL-1βmRNA的表达具有抑制作用，并呈剂量依赖关系。免疫组化染色证实ActRⅡA在巨噬细胞中高表达，激活素A对巨噬细胞表达ActRⅡA mRNA具有促进作用，采用抗ActRⅡA抗体可以阻断激活素A促进IL-1βmRNA表达作用，进一步检测表明激活素作用后ActRIP2 mRNA表达亦增加。结论：激活素与LPS比较可能是IL-1分泌的弱激动剂，激活素单独应用显示刺激IL-1分泌作用，而与LPS共同作用，则呈现抑制LPS强刺激作用；激活素可能通过ActRⅡA-ActRIP2受体信号传导途径，调控巨噬细胞IL-1β分泌与合成。     

激活素ⅡA型受体在免疫细胞上的表达

目的　探讨激活素ⅡA受体 (ActRⅡA)在免疫细胞中的表达 ,揭示激活素 (Activin)对免疫细胞的作用方式。方法　以ActRⅡAC末端肽作为抗原免疫家兔制备特异性抗ActRⅡAC末端抗体 ,通过免疫细胞化学染色技术观察ActRⅡA在免疫细胞上的分布。RT PCR检测ActRⅡAmRNA表达情况 ,硝酸还原酶法检测小鼠腹腔巨噬细胞产生NO水平。结果　采用特异性抗ActRⅡAC末端抗体进行免疫细胞化学染色 ,结果显示ActRⅡA在小鼠巨噬细胞上高水平表达 ,而在其它免疫细胞 (T、B、NK、DC)上未见表达。RT PCR检测结果进一步表明ActRⅡAmRNA在巨噬细胞中表达。硝酸还原酶法检测结果显示 ,激活素A能明显抑制LPS刺激的巨噬细胞NO的产生。结论　ActRⅡA主要在巨噬细胞上高水平表达 ,提示激活素可通过ActRⅡA介导的信号传导途径参与巨噬细胞功能调控。     

激活素A对RAW264.7巨噬细胞活性的调节作用

目的探讨激活素A对参与炎症反应的小鼠巨噬细胞活性调节作用。方法以LPS刺激活化的小鼠巨噬细胞系RAW264．7细胞作为阳性参照,ELISA法检测激活素A及LPS刺激的小鼠腹腔巨噬细胞系RAW264．7细胞IL-1β分泌水平,还原酶法分析NO分泌水平,RT-PCR检测IL-1β和iNOS mRNA的表达,瑞氏染色检测RAW264．7细胞吞噬活性。结果在激活素A刺激下RAW264．7细胞IL-1β和NO分泌水平均明显升高,IL-1β和iNOS mRNA表达亦增加,巨噬细胞吞噬活性增强;激活素A和LPS共刺激RAW264．7细胞时,激活素A明显抑制LPS刺激的RAW264．7细胞IL-1β和NO产生水平,以及IL-1β和iNOS mRNA表达,巨噬细胞吞噬活性也明显低于LPS单独刺激组。结论激活素对巨噬细胞的活性调节具有双重作用,这种作用与巨噬细胞的激活状态有关。     

激活素A诱导小鼠Ⅱ型巨噬细胞活化

目的:探讨激活素A对原代培养小鼠腹腔巨噬细胞活化的影响。方法:ELISA法检测激活素A,RT-PCR法检测iNOS mRNA表达,流式细胞术检测CD86及Arginase-1的表达。结果:LPS以时间依赖方式促进小鼠腹腔巨噬细胞分泌激活素A,激活素A能明显促进巨噬细胞活化标志CD86分子表达。LPS明显促进Ⅰ型巨噬细胞标志iNOS mRNA表达,而激活素A则主要促进Ⅱ型巨噬细胞标志Arginase-1的表达。结论:激活素A可能以自分泌/旁分泌形式促进小鼠II型巨噬细胞活化。     

激活素受体相互作用蛋白3的基因克隆及其免疫学特性研究

目的：研究新克隆的激活素受体相互作用蛋白3（ActRIP3）的免疫学特性和其介导Ser／Thr激酶型受体胞内信号传导的作用。方法：以酵母双杂交法发现的ActRIP基因片段作为探针，从小鼠脑cDNA文库中克隆ActRIP3基因。EIA法分析其与激活素ⅡA型受体（ActRⅡA）结合能力，Westernblot杂交检测成熟蛋白在组织中的表达，免疫组化染色分析其在脑组织中的分布，采用pcDNA-AetRIP3与CAGA-1ux报告基因质粒共转染HEK293细胞分析信号传导作用。结果：克隆的ActRIP3基因全长1197bp，编码101个氨基酸残基，EIA分析显示ActRIP3与ActRⅡA具有特异性结合作用，这种作用与ActRIP3的N末端氨基酸序列有关。Westernblot杂交显示天然ActRIP3相对分子质量约为14000，在多种组织表达，免疫组化染色显示其在脑组织中的分布以海马及下丘脑为主。通过表达ActRIP3可促进激活索诱导的特异性基因转录活性。结论：ActRIP3属于ActRIP家族新成员，具有特异结合ActRⅡA的能力，并具有促进激活素信号传导的作用。     

激活TLR5 和NLRC4 通路对小鼠先天免疫细胞的影响

目的：探讨用重组鞭毛素蛋白同时或者分别激活C57BL/6小鼠模型TLR5和NLRC4通路对小鼠先天免疫细胞的影响。方法：首先,表达和纯化重组鞭毛素蛋白即全长鞭毛素蛋白FliC（同时激活TLR5和NLRC4两条通路）; FliCΔ90-97（不能激活TLR5通路）;FliC-L3A（不能激活NLRC4通路）;FliCΔ90-97:L3A（两条通路都不激活）。将小鼠分为5组,分别为:PBS组、FliC组、FliC-L3A组、FliCΔ90-97和FliCΔ90-97:L3A组。分别用PBS和10 μg重组鞭毛素蛋白腹腔注射C57BL/6小鼠,每组3只。12 h后收集腹腔灌洗液,流式抗体染色检测腹腔灌洗液中的中性粒细胞和NK细胞的比例。同时,取小鼠脾脏制成脾细胞悬液,流式抗体染色检测DC表面共刺激分子CD80和CD86的表达情况及脾细胞中调节性T细胞（Treg）的比例。结果：激活TLR5（FliC组和FliC-L3A组）和NLRC4通路（FliCΔ90-97组）小鼠的腹腔灌洗液中中性粒细胞和NK细胞的比例都显著高于PBS组和FliCΔ90-97:L3A组（P <0.01）。激活TLR5通路的FliC组和FliC-L3A组的DC表面CD80和CD86表达水平显著高于PBS组、FliCΔ90 97和FliCΔ90-97:L3A组（P<0.01）。FliC-L3A组调节性T细胞的比例高于其他组（P<0.05）。结论：激活TLR5和NLRC4通路可以趋化中性粒细胞、NK细胞,两条通路激活对中性粒、NK细胞有相同的趋化能力。鞭毛素蛋白只有激活TLR5通路才可以上调DCs表面共刺激分子CD80和CD86,促进DCs的成熟。     

ActRIPs在激活素受体信号传导中的作用

激活素属于TGF-β超家族成员的多功能因子,其受体属于TGF-β超家族的Ser/THr激酶型受体,由Ⅰ型和Ⅱ型组成,Ⅱ型受体与配体激活素特异结合,再激活Ⅰ型受体,进一步通过Smad蛋白家族的级联反应将信号传入胞核。最新的研究发现Ser/THr激酶型受体介导的信号传导实际上受控于Ⅱ型受体,细胞内激活素受体相互作用蛋白(ActRIPs)参与了Ⅱ型受体的活性调控,ActRIPs蛋白家族具有与激活素Ⅱ型A受体(ActRⅡA)C末端特异结合的活性,不同的ActRIPs具有不同的作用,Ac-tRIP1以脚手架形式与ActRⅡA及Smad3结合,抑制细胞内Smad途径信号传导;ActRIP2与ActRⅡA结合后,通过其C末端介导受体内吞作用,对信号传导也具有抑制作用;ActRIP3则与ActRIP1,2不同,其与ActRⅡA结合后,具有促进信号传导的作用。ActRIPs的发现,使人们更清晰地认识到Ser/THr激酶型受体介导的信号传导调控机制。     

红车轴草提取物对小鼠淋巴细胞[Ca2+]i及腹腔巨噬细胞NO分泌和吞噬的影响

目的探讨红车轴草提取物(Trifoliumpratense Leguminosae extract,TLE)体外对小鼠淋巴细胞[Ca2+]i及腹腔巨噬细胞NO分泌和吞噬微球的影响。方法无菌条件下制备小鼠淋巴细胞悬液及小鼠腹腔巨噬细胞悬液;MTT法检测药物对细胞悬液的毒性情况;Fluo-4/AM染色结合流式细胞术分析TLE对小鼠淋巴细胞[Ca2+]i的影响;Griess反应系统检测TLE对脂多糖(LPS)刺激的小鼠腹腔巨噬细胞NO分泌的影响;1μm与2μm直径的荧光微球结合流式细胞术分析TLE对小鼠腹腔巨噬细胞吞噬作用的影响。结果终质量浓度为20、40mg/L的TLE对细胞的毒性小;TLE促进了淋巴细胞的Ca2+内流;TLE抑制了巨噬细胞的NO分泌与吞噬作用,与非TLE组比较P<0.01。结论对淋巴细胞[Ca2+]i及巨噬细胞的NO分泌和吞噬的作用可能是TLE调节小鼠免疫系统的途径。     

脱水淫羊藿素对小鼠巨噬细胞免疫功能的影响

目的:研究脱水淫羊藿素(AHI)在体外对脂多糖(LPS)诱导的小鼠巨噬细胞免疫功能的影响。方法:分离制备小鼠骨髓来源巨噬细胞;CCK-8法检测不同终浓度的AHI对巨噬细胞的毒性;采用Griess试剂盒检测AHI对巨噬细胞产生NO的影响;流式细胞术(FCM)检测AHI对巨噬细胞吞噬E.coli颗粒的影响;利用FCM结合双色免疫荧光染色技术检测AHI对巨噬细胞早期活化标志CD69的表达情况;使用流式液相蛋白定量检测技术(CBA)检测AHI对LPS刺激巨噬细胞分泌细胞因子的影响。结果:终浓度为2.5、5、10μmol/L的AHI对活化的小鼠巨噬细胞均具有明显的免疫抑制作用,特别是5μmol/L AHI能明显抑制经LPS刺激的巨噬细胞早期活化,释放NO,吞噬E.coli颗粒,以及分泌IL-6、MCP-1、TNF和IL-12p70四种细胞因子。结论:AHI对LPS诱导的小鼠巨噬细胞的活化具有明显的抑制作用,是一种潜在的免疫抑制剂。     

ARIP2在小鼠巨噬细胞系RAW264.7中对IL-1β分泌的抑制作用

研究ARIP2在巨噬细胞中对IL-1β分泌的调节作用,探讨激活素A与巨噬细胞活化的可能关系及其作用机制。为了分析ARIP2在小鼠巨噬细胞系RAW264.7细胞中的表达及其生物学作用,实验采用RT-PCR方法检测RAW264.7细胞中ARIP2 mRNA的表达,ELISA方法观察过表达ARIP2对RAW264.7细胞分泌IL-1β的影响。RAW264.7细胞能够表达特异性ARIP2 mRNA,其RNA表达受激活素A刺激呈剂量依赖性增加。ELISA检测结果显示过表达ARIP2可以抑制RAW264.7细胞分泌IL-1β。上述资料提示ARIP2不仅具有抑制激活素诱导的特异基因转录活性,其自身也具有多种生物学活性,可能在激活素A抑制LPS活化巨噬细胞分泌IL-1方面,发挥关键性信号转导调控作用。     

Identification of Activin A and Follistatin in Human Milk

Activin A is a dimeric protein member of the transforming growth factor- &#103 (TGF- &#103 ) family: it is synthesized by a variety of organs and follistatin is an activin-binding protein. A sensitive and specific assays for bioactive dimeric activin A and follistatin have recently allowed to measure these proteins in blood and other biological fluids, giving a new insights into their possible physiological role. Since human breast is able to produce activin A, the aim of the present study was to evaluate whether it and follistatin are measurable in breast milk of women during lactation. Concentrations of activin A and follistatin were measured in milk samples collected at 3, 5 and 30 days after delivery by using specific and sensitive two-site ELISAs. For the first time the presence of immunoreactive activin A and follistatin in human milk has been shown; no significant different concentration between the third and the fifth day after delivery was found. Furthermore, no difference of activin A and follistatin concentration between the whole and the skim milk or between spontaneous delivery and cesarean section was found. Milk activin A and follistatin concentrations after 1 month of lactation were significantly decreased (P <0.01). Activin A and follistatin are present in human milk in high concentrations in the first week of lactation, while decrease after a month suggesting a possible role as growth factors in human milk.     

Genomic organization and mapping of the human activin receptor type IIB (hActR-IIB) gene

Activins, members of a family of proteins that includes transforming growth factor-beta (TGF-beta), are gonadal polypeptide hormones that stimulate secretion of follicle-stimulating hormone (FSH). During large-scale sequencing analysis of a 1.2-Mb fragment of human genomic DNA on 3p22–p21.3, we found the gene encoding activin receptor type IIB (hActR-IIB). Comparison of its reported cDNA sequence with this genomic sequence showed that the hActR-IIB gene consists of 11 exons and spans about 30 kb of genomic DNA. Received: August 11, 1997/Accepted: October 22, 1997     

High levels of maternal serum IL-17 and activin A in pregnant women affected by systemic lupus erythematosus

Citation
Torricelli M, Bellisai F, Novembri R, Galeazzi LR, Iuliano A, Voltolini C, Spreafico A, Galeazzi M, Petraglia F. High levels of maternal serum IL‐17 and activin A in pregnant women affected by systemic lupus erythematosus. Am J Reprod Immunol 2011; 66: 84–89 Problem To evaluate changes of serum IL‐17, activin A, follistatin, and other cytokines during pregnancy in women with systemic lupus erythematosus (SLE). Method of study A group of patients with SLE and controls were longitudinally studied, collecting a blood sample before and during three trimesters of pregnancy. Serum activin A, follistatin, IL‐17, IL‐6, IL‐10, and TNF‐α concentrations were evaluated by specific ELISA. Results Before pregnancy, while serum IL‐17, IL‐6, IL‐10, and TNF‐α resulted significantly higher in women with SLE (P < 0.001), activin A and follistatin were not changed. Serum IL‐17 concentrations were higher in SLE than in controls with no changes during pregnancy. IL‐6 increased in both groups, resulting higher in SLE than in controls only in the first trimester (P < 0.05). IL‐10 concentration in SLE increased during pregnancy resulting significantly higher than in controls (P < 0.01). TNF‐α levels were higher in SLE than in controls in third trimester (P < 0.01). Serum activin A levels in SLE were significantly higher than in controls (P < 0.001) at third trimester. Conclusion Women with SLE show increased secretions of activin A, IL‐17, IL‐6, IL‐10, and TNF‐α during gestation, with a different trend for the various cytokines. These data suggest that patients with SLE have a hyper‐reactive immune system, probably receiving a placental contribution.     

激活素A对L929成纤维细胞迁移、侵袭及细胞因子分泌的影响

目的探讨激活素A(activin A)对小鼠成纤维细胞系L929细胞迁移、侵袭及细胞因子分泌的影响。方法采用5-溴-2’-脱氧尿嘧啶核苷(5-bromo-2’-deoxyuridine,BrdU)掺入实验检测L929细胞增殖,酶联免疫吸附实验(ELISA)检测L929细胞培养上清中细胞因子水平,基质胶transwell侵袭实验分析L929细胞迁移、侵袭,实时细胞分析技术(RTCA)检测L929细胞黏附,Western blot分析细胞内信号蛋白表达水平。结果与对照组相比,激活素A处理对L929细胞增殖没有影响,对L929细胞分泌TNF-α、IL-1β及IL-6等促炎细胞因子也没有影响,但却显著促进纤维化诱导因子TGF-β1分泌。激活素A还能显著增加L929细胞穿透基质胶迁移、侵袭细胞数量(P<0.01),并促进L929细胞黏附,添加阻断剂FST可以显著减弱激活素A诱导的L929细胞侵袭和促进黏附作用。激活素A处理L929细胞可以显著增加p-ERK和p-JNK蛋白水平,但对p-Smad3蛋白水平没有明显影响。结论激活素A可以促进L929细胞分泌TGF-β1、诱导L929细胞侵袭和促...     

激活素受体样激酶1促进人脐静脉内皮细胞增殖和迁徙

目的： 研究激活素受体样激酶1（ALK1）对人脐静脉内皮细胞的作用。 方法： 体外培养人脐静脉内皮细胞（HUVECs），RT-PCR分析ALK1和ALK5在HUVEC激活状态下表达的变化。脂质体转染pcDNA3.1+ALK1到HUVECs，流式细胞仪检测HUVECs增殖的改变，boyden小室检测ALK1对HUVECs迁徙的影响。 结果： ALK1在HUVEC安静状态高表达，ALK1能促进HUVECs的增殖和迁徙。 结论： ALK1通过促进内皮细胞的增殖和迁徙在血管重塑中发挥作用。     

活化素受体样激酶1及其在血管生成中的作用

正血管生成是指新的血管从已存在的毛细血管网生成的过程,受血管生成促进因子和抑制因子的严格调控。通常,血管生成发生于胚胎和出生后早期血管的发育过程中,除女性生理周期和伤口愈合等过程外,在成年阶段血管生成已处于静息状态。但是,在发生某些疾病如肿瘤、糖尿病视网膜病变、心血管疾病及类风湿性关节炎[1-2]时,血管生成过程被异常激活。活化素受体样激酶1(activin receptor-like     

A novel 1,25-dihydroxyvitamin D–activin A pathway in human alveolar macrophages is dysfunctional in patients with pulmonary alveolar proteinosis (PAP)

We have shown that activin A, a cytokine implicated in regulating B-cell proliferation, is severely deficient in alveolar macrophages from patients with pulmonary alveolar proteinosis (PAP), an autoimmune disorder characterized by surfactant accumulation and neutralizing autoantibodies to granulocyte–macrophage colony stimulating factor. Mechanisms of activin regulation in alveolar macrophages are not well understood. Based on previous gene array results from PAP bronchoalveolar lavage cells suggesting deficiencies in vitamin D target genes, and on recent evidence of vitamin D receptor elements (VDREs) in the human activin A gene promoter, we investigated the effects of 1,25-dihydroxyvitamin D (vitamin D₃) on activin A expression in alveolar macrophages from healthy individuals and PAP patients. Activin A expression was stimulated by LPS in cultures of either healthy control or PAP alveolar macrophages; in contrast, vitamin D₃ increased activin A only in healthy controls but not in PAP. Compared to healthy controls, freshly obtained (uncultured) PAP alveolar macrophages displayed healthy intrinsic vitamin D receptor expression but deficient expression of vitamin D target genes, cathelicidin and thioredoxin interacting protein. PAP patients also demonstrated a relative insufficiency of circulating vitamin D. Investigation of activin A in murine alveolar macrophages confirmed a lack of functional response to vitamin D as anticipated since murine activin A does not contain VDREs. Results suggest that mechanisms of activin A deficiency in PAP alveolar macrophages may involve dysregulation of a novel species-specific vitamin D–activin A pathway.