Apigenin ameliorates imiquimod-induced psoriasis in C57BL/6J mice by inactivating STAT3 and NF-κB

Psoriasis is a chronic autoimmune disease featured by patches on the skin.It is caused by malfunction of immune cells and keratinocytes with inflammation as one of its key features.Apigenin(API)is a natural flavonoid with anti-inflammatory and immunoregulatory properties.Therefore,we speculated that API can ameliorate psoriasis,and determined its effect on the development of psoriasis by using imiquimod(IMQ)-induced psoriasis mouse model.Our results showed that API attenuated IMQ-induced phenotypic changes,such as erythema,scaling and epidermal thickening,and improved splenic hyperplasia.Abnormal differentiation of immune cells was restored in API-treated mice.Mechanistically,we revealed that API is a key regulator of signal transducer activator of transcription 3(STAT3).API regulated immune responses by reducing interleukin-23(IL-23)/STAT3/IL-17A axis.Moreover,it suppressed IMQ-caused cell hyperproliferation by inactivating STAT3 through regulation of extracellular signal-regulated kinase 1/2 and nuclear factor-κB(NF-κB)pathway.Furthermore,API reduced expression of inflammatory cytokines through inactivation of NF-κB.Taken together,our study demonstrates that API can ameliorate psoriasis and may be considered as a strategy for psoriasis treatment.

Promising Effects of Zerumbone on the Regulation of Tumor-promoting Cytokines Induced by TNF-α-activated Fibroblasts

Inflammation plays an important role in the development of several cancers.Inflammatory cytokines,including tumor necrosis factor-α(TNF-α),are associated with the induction of inflammation.Chronic inflammation contributes to the progression of cancer through several mechanisms,including increased cytokine production and activation of transcription factors,such as nuclear factor-κB(NF-κB).Zerumbone(ZER),a component of subtropical ginger(Zingiber zerumbet Smith),seems to have anti-inflammatory,anti-cancer,and antioxidant activities.In this study,we aimed to explore the protective function and mechanisms of ZER against TNF-α-induced cancer-promoting cytokines.We found that the viability of stimulated human fibroblast cell lines was reduced after treatment with ZER(IC50=18µmol/L),compared to un-stimulated fibroblasts(IC50=40µmol/L).Besides,ZER inhibited mRNA expression and protein secretion of transforming growth factor-β(TGF-β),interleukin-33(IL-33),monocyte chemoattractant protein-1(MCP-1),and stromal cell-derived factor 1(SDF-1),which were produced by TNF-α-induced fibroblasts,as measured by quantitative real time-PCR(qRT-PCR)and ELISA assays.The mRNA expression levels of TGF-β,IL-33,SDF-1,and MCP-1 showed 8,5,2.5,and 4-fold reductions,respectively.Moreover,secretion of TGF-β,IL-33,SDF-1,and MCP-1 was reduced to 3.65±0.34 ng/mL,6.3±0.26,1703.6±295.2,and 5.02±0.18 pg/mL,respectively,compared to the untreated group.In addition,the conditioned media(CM)of TNF-α-stimulated fibroblasts increased the NF-κB expression in colorectal cancer cell lines(HCT-116 and Sw48),while in the vicinity of ZER,the expression of NF-κB was reversed.Considering the significant effects of ZER,this component can be used as an appropriate alternative herbal treatment for cancer-related chronic inflammation.

Relationship between Carbachol Hyperstimulation-induced Pancre-atic Intracelluar Trypsinogen and NF-κB Activation in Rats in vitro

The relationship between intracelluar trypsinogen activation and NF-κB activation in rat pancreatic acinar cells induced by M3 cholinergic receptor agonist （carbachol） hyperstimulation was studied. Rat pancreatic acinar cells were isolated, cultured and treated with carbachol, the active protease inhibitor （pefabloc） and NF-κB inhibitor （PDTC） in vitro. Intracelluar trypsin activity was measured by using a fluorogenic substrate. The activity of NF-κB was monitored by using electrophoretic mobility shift assay. The results showed that after pretreatment with 2 mmol/L pefabloc, the activities of trypsin and NF-κB in pancreatic acinar cells treated with high concertrations of carbachol （10^-3 mol/L） in vitro was significantly decreased as compared with control group （P〈0.01 ）. The addition of 10^-2 mol/L PDTC resulted in a significant decrease of NF-κB activities in pancreatic acinar cells after treated with high concertrations of carbachol （10^-3 mol/L） in vitro, but the intracelluar trypsinogen activity was not obviously inhibited （P〉0.05）. It was concluded that intracelluar trypsinogen activation is likely involved in the regulation of high concertrations of carbachol-induced NF-κB activation in pancreatic acinar cells in vitro. NF-κB activation is likely not necessary for high concertrations of carbachol-induced trypsinogen activation in pancreatic acinar cells in vitro.

Relationship between Carbachol Hyperstimulation-Induced Pancreatic Acinar Cellular Injury and Trypsinogen or NF-κB Activation in Rats in vitro

The relationship between M3 cholinergic receptor agonist （carbachol） hyperstimulationinduced pancreatic acinar cellular injury and trypsinogen activation or NF-κB activation in rats was studied in vitro. Rat pancreatic acinar ceils were isolated, cultured and treated with carbachol, the active protease inhibitor （pefabloc）, and NF-κB inhibitor （PDTC） in vitro. Intracellular trypsin activity was measured by using a fluorogenic substrate. The cellular injury was evaluated by measuring the leakage of LDH from pancreatic acinar ceils. The results showed that as compared with control group, 10-3 mol/L carbachol induced a significant increase of the intracellular trypsin activity and the leakage of LDH from pancreatic acinar cells. Pretreatment with 2 mmol/L pefabloc could significantly decrease the activity of trypsin and the leakage of LDH from pancreatic acinar cells （P〈0. 01） following the treatment with a high concentration of carbachol （10^-3 mol/L） in vitro. The addition of 10^-2mol/L PDTC didn＇t result in a significant decrease in the activity of trypsin and the leakage of LDH from pancreatic acinar cells treated with a high concentration of carbachol （10^-3 mol/L） in vitro （P〉0. 05）. It was concluded that intracellular trypsinogen activation is likely involved in pancreatic acinar cellular injury induced by carbachol hyperstimulation in vitro. NF-κB activation may not be involved in pancreatic acinar cellular injury induced by carbachol hyperstimulation in vitro.

Inhibitory Actions of Tetrandrine on Tumor Necrosis Factor α-Induced NF-κB Activation in Neovascularization of Cultured Choroidal Explants

Tetrandrine (1 μM), a bis-benzylisoquinoline alkaloid isolated from Stephania tetrandra S Moore, signifi-cantly decreased tumor necrosis factor alpha (TNFα;10 ng/ml)-induced increase in the number of micro vessels that budded from cultured rat choroidal explants. Tetrandrine also decreased the TNFα-induced in-crease in the number of cells composing the microvessels. Ammonium pyrrolidine dithiocarbamate (APDC;0.1-0.3 μM), an inhibitor of nuclear factor-κB (NF-κB), decreased the TNFα-induced increase in the number of microvessels in a concentration-dependent manner. TNFα increased the phosphorylation and degradation of inhibitor of NF-κB (IκBα), as well as increasing the DNA-binding activity of NF-κB in choroidal explants. TNF? induced an increase of vascular endothelial growth factor (VEGF)-A mRNA, but not VEGF-C mRNA or VEGF-D mRNA. TNFα-induced angiogenic action was inhibited by treatment of VEGF-A antibody in cultured choroidal capillaries. Tetrandrine inhibited the TNFα-induced increases of phosphorylation and degradation of IκBα, and reduced the TNFα-induced increase of DNA-binding activity of NF-κB in chor-oidal explants. In conclusion, tetrandrine inhibits TNFα-induced activation of NF-κB in the choroidal capil-laries via inhibition of TNFα-induced phosphorylation of IκBα.

血清MBL、BAFF与磷脂酶A2受体相关特发性膜性肾病患者肾功能及疗效的关系

目的探讨血清甘露聚糖结合凝集素(MBL)、肿瘤坏死因子家族B细胞活化因子(BAFF)与磷脂酶A2受体(PLA2R)相关特发性膜性肾病(IMN)患者肾功能和疗效的关系。方法选取PLA2R相关IMN患者103例作为观察组,并根据疗效将PLA2R相关IMN患者分为未缓解组(n=44)、缓解组(n=59);同期另选健康体检志愿者67例作为对照组。收集相关资料;用酶联免疫吸法检测血清MBL、BAFF、24 h尿蛋白,PA速率微板法试剂盒检测血肌酐,计算估计肾小球滤过率(eGFR)。Spearman相关法分析PLA2R相关IMN患者血清MBL、BAFF水平与肾功能指标的相关性;多因素Logistic回归分析影响PLA2R相关IMN患者疗效的因素,受试者工作特征(ROC)曲线分析血清MBL、BAFF对PLA2R相关IMN患者治疗未缓解的预测价值。结果观察组血清MBL、BAFF水平及24 h尿蛋白高于对照组,eGFR低于对照组(P均<0.05)。PLA2R相关IMN患者血清MBL、BAFF水平与eGFR呈负相关(r分别为-0.777、-0.760,P均<0.05),与24 h尿蛋白呈正相关(r分别为0.883、0.828,P均<0.05)。未缓解组白蛋白、eGFR低于缓解组,24 h尿蛋白、MBL、BAFF高于缓解组(P均<0.05),两组性别、年龄、血肌酐、血尿酸、血尿素氮、总胆固醇、甘油三酯、IgG、补体3和PLA2R抗体滴度比较差异无统计学意义(P均>0.05)。白蛋白和eGFR升高为PLA2R相关IMN患者疗效的独立保护因素(P均<0.05),24 h尿蛋白、MBL和BAFF升高为独立危险因素(P均<0.05)。ROC曲线分析结果显示,血清MBL、BAFF联合预测PLA2R相关IMN患者治疗未缓解的曲线下面积(0.880)大于二者单独预测(0.791、0.787),比较差异有统计学意义(Z分别为2.694、2.613,P均<0.05)。结论血清MBL、BAFF水平升高与PLA2R相关IMN患者肾功能降低及疗效差有关,二者联合检测预测PLA2R相关IMN患者治疗未缓解的价值较高。

NF-κB和STAT3对宫颈癌作用的研究进展

宫颈癌是女性第二好发的恶性肿瘤,对于晚期患者,放疗联合化疗是主要的治疗方法。但放化疗诱导的炎症使肿瘤产生了治疗抵抗并引起正常组织的损伤。其中激活的转录因子核因子-κB（nuclear factor-κB,NF-κB）和信号转导及转录激活因子3（signal transducer and activator of transduction 3,STAT3）,是炎症反应的中心环节。

反式激活蛋白-NEMO结合域抑制胆红素诱导的大鼠皮层星形胶质细胞NF-κB活化

目的明确反式激活蛋白-NEMO结合域(TAT-NBD)对胆红素诱导的大鼠皮层星形胶质细胞核因子-κB(NF-κB)活化及炎症反应的作用。方法分离并鉴定新生SD大鼠大脑皮质星形胶质细胞,随机分为对照组、胆红素组、TAT-NBD干预组。免疫荧光观察各组细胞形态,改良MTT检测细胞相对存活率。Western blot检测NF-κB p65表达,EMSA检测NF-κB的入核、活化。ELISA法检测培养基上清炎症因子IL-1β、TNF-α、IL-6水平。结果胆红素组NF-κB p65蛋白灰度比值明显高于对照组(P<0.01),2、12 h达高峰(P<0.05);TAT-NBD干预组NF-κB p65蛋白表达明显低于胆红素组(P<0.01)。IL-1β、TNF-α、IL-6的释放与胆红素诱导的NF-κB p65表达有时间相关性,于12 h达高峰,且TAT-NBD干预2、12 h的IL-1β、TNF-α、IL-6浓度均低于胆红素组(P<0.01)。星形胶质细胞的存活率与胆红素作用时间呈负相关,TAT-NBD干预2、12 h的相对存活率均高于胆红素组(P<0.05)。结论胆红素可诱导原代培养的大鼠星形胶质细胞NF-κB激活、过表达,TAT-NBD抑制NF-κB的活化高峰、减少炎症因子释放产生抗炎作用,可用于预防胆红素脑损伤。

Increased Expression of Receptor Activator of Nuclear Factor-κB Ligand in Osteoblasts from Adolescent Idiopathic Scoliosis Patients with Low Bone Mineral Density

Persistent generalized low bone mineral density (BMD) has been reported in patients with adolescent idiopathic scoliosis (AIS).However,the exact mechanisms and causes of the low BMD in AIS patients are largely unknown.The purpose of this study was to examine the relationship between the receptor activator of NF-κB ligand (RANKL)/osteoprotegerin (OPG) levels in osteoblasts (OBs) from AIS patients with low BMD and with comparison made between the patients and controls.Twenty AIS patients and eight age-matched controls were included in the present study.The BMD of lumbar spine and proximal femur was measured in all subjects.OBs from the cancellous bone of each subject was harvested and primarily cultured.The mRNA and protein expression of RANKL and OPG in OBs was detected by RT-PCR and Western blotting.The results showed BMD was lower in AIS patients than in controls.A significantly higher mRNA and protein expression of RANKL was observed in OBs from AIS patients,while no significant difference was found in the expression of OPG between AIS patients and controls.As a result,RANKL/OPG ratio in patients with AIS was remarkably higher than controls.Our study preliminarily demonstrated expression of RANKL was higher in OBs from AIS patients with low BMD as compared with controls,suggesting the unbalanced RANKL/OPG ratio caused by an over-expression of RANKL in OBs may be responsible for the low BMD in AIS patients.

Nuclear Factor-κB Signaling Mediates Antimony-induced Astrocyte Activation

Objective Antimony(Sb)has recently been identified as a novel nerve poison,although the cellular and molecular mechanisms underlying its neurotoxicity remain unclear.This study aimed to assess the effects of the nuclear factor kappa B(NF-κB)signaling pathway on antimony-induced astrocyte activation.Methods Protein expression levels were detected by Western blotting.Immunofluorescence,cytoplasmic and nuclear fractions separation were used to assess the distribution of p65.The expression of protein in brain tissue sections was detected by immunohistochemistry.The levels of mRNAs were detected by Quantitative real-time polymerase chain reaction(qRT-PCR)and reverse transcriptionpolymerase chain reaction(RT-PCR).Results Antimony exposure triggered astrocyte proliferation and increased the expression of two critical protein markers of reactive astrogliosis,inducible nitric oxide synthase(iNOS)and glial fibrillary acidic protein(GFAP),indicating that antimony induced astrocyte activation in vivo and in vitro.Antimony exposure consistently upregulated the expression of inflammatory factors.Moreover,it induced the NF-κB signaling,indicated by increased p65 phosphorylation and translocation to the nucleus.NF-κB inhibition effectively attenuated antimony-induced astrocyte activation.Furthermore,antimony phosphorylated TGF-β-activated kinase 1(TAK1),while TAK1 inhibition alleviated antimonyinduced p65 phosphorylation and subsequent astrocyte activation.Conclusion Antimony activated astrocytes by activating the NF-κB signaling pathway.

奶牛乳房炎金黄色葡萄球菌FnbpB-D基因的表达及其抗血清活性

纤维素结合蛋白B(FnbpB)是金黄色葡萄球菌(S.aureus)最主要的黏附因子之一,它能够介导S.aureus结合于细胞表面的纤维连结素(Fn)和纤维蛋白原(Fg)。FnbpB基因中D区为主要活性部位。本实验利用pET-32a表达载体表达了S.aureus FnbpB-D重组蛋白(34.7ku),并通过动物实验对重组FnbpB-D蛋白的抗血清活性进行了初步研究。采用ELISA对抗血清进行抗粘附性检测,结果显示实验组与对照组差异极显著(p<0.01),抗血清具有较强的抑制S.aureus黏附纤维连结素的作用。此外,调理吞噬实验结果显示,免疫兔全血对S.aureus有较强的调理作用。这些实验结果将为制备奶牛乳房炎S.aureus黏附素疫苗的研制提供参考。

人参皂苷Rbl对阿霉素心力衰竭大鼠心肌细胞核因子-κB的影响

目的探讨人参皂苷Rbl(Gs-Rb1)改善阿霉素(Adr)慢性心力衰竭(CHF)效应是否与抑制核因子-κB(NF-κB)有关。方法 Adr诱导CHF大鼠模型被随机分为Adr组(n=15)和Gs-Rbl组(70 mg.kg-1.d-1,n=17),另随机选取同龄健康大鼠作为对照(n=10);同时培养乳鼠心肌细胞并随机分为对照组、Adr组(1μmol.L-1)和Gs-Rbl组(1μmol.L-1Adr+200μmol.L-1 Gs-Rbl)。干预完毕后,检测心脏超声、NF-κB、IκBα、p-IκBα和NF-κB DNA结合活性。结果 (1)Gs-Rb1组LVEF明显改善(P=0.003);(2)在NF-κB p50和NF-κB p65方面,体内或体外的Gs-Rbl组均明显低于Adr组(P<0.001);(3)体内、体外的Gs-Rbl组NF-κBDNA结合活性明显低于Adr组(P<0.01);(4)体内、体外的Adr组IκBα蛋白明显高于对照组,而Gs-Rbl组IκBα最高(P<0.01);Gs-Rbl组p-IκBα和p-IκBα/IκBα比值明显低于Adr组(P<0.01)。结论 Gs-Rb1改善CHF效应与其抑制NF-κB活性有关。

Ⅱ型志贺样毒素B亚单位的重组表达及其受体结合活性

目的:在大肠杆菌中重组表达Ⅱ型志贺样毒素B亚单位(Stx2B),并对其表达形式和受体结合活性进行分析。方法:PCR方法从肠出血性大肠杆菌(EHEC)O157:H7中钓取Stx2B编码基因,利用基因克隆技术构建重组大肠杆菌pET-stx2B/BL21,IPTG诱导目的蛋白高效表达并对表达的包涵体进行变性和复性处理,离子交换层析纯化蛋白。通过SDS-PAGE变性和非变形蛋白电泳,分析重组Stx2B的表达形式,并利用Hela细胞结合模型,评价重组Stx2B与细胞受体的结合活性。结果:构建的重组大肠杆菌pET-stx2B/BL21能高效表达Stx2B,经变性、复性及离子交换层析操作,获得高纯度的目的蛋白。SDS-PAGE变性和非变形蛋白电泳分析显示,重组Stx2B以二聚体形式存在,单体之间通过二硫键相连。细胞结合试验显示,重组Stx2B与Hela细胞具有特异结合活性。结论:成功构建表达Stx2B的基因工程菌,Stx2B的受体结合活性不依赖于五聚体形式。

B_(19)-Gly-B_(20)人胰岛素的分离纯化及性质研究

目的研究胰岛素B链羧端的自由度对于胰岛素与受体相互作用的影响。方法在人胰岛素B链羧端 β转角区回折点B1 9与B2 0 之间插入一个Gly。结果B1 9 Gly B2 0 人胰岛素原的表达产物占细胞总蛋白量的 3 0 % ,B1 9 Gly B2 0 人胰岛素的受体活性是标准猪胰岛素的 12 1%。结论以较高的受体结合活性获得了高纯度的B1 9 Gly B2 0 人胰岛素。

B_(23)-Gly-B_(24)人胰岛素的分离纯化及性质研究

为了研究胰岛素B链羧端的自由度对于胰岛素与受体相互作用的影响。在人胰岛素B链羧端（转角区回折点B23与B24之间插入一个Gly。B23-Gly-B24人胰岛素原在大肠杆菌的表达产物占细胞总蛋白量的28％,B23-Gly-B24人胰岛素的受体活性分别是标准猪胰岛素的122％和人胰岛素的111％。说明以较高的受体结合活性获得了高纯度的B23-Gly-B24人胰岛素。

清热利湿活血方对HBV转基因小鼠的抗病毒作用及对TKB1-IRF3表达的影响

【目的】观察清热利湿活血方对乙型肝炎病毒(HBV)转基因小鼠的抗病毒作用及对肝组织TANK结合激酶1(TKB1)、干扰素调控因子3(IRF3)表达的影响,以阐明其作用机制。【方法】首先建立清热利湿活血方的HPLC指纹图谱。再将HBV转基因小鼠随机分为4组,即模型组,苦参素组,清热利湿活血方高、低剂量组,每组8只。苦参素组小鼠给予灌胃剂量为0.15 g·kg^(-1)·d^(-1)的苦参素混悬液,清热利湿活血方高、低剂量组小鼠分别给予灌胃剂量为7、2 g·kg^(-1)·d^(-1)的清热利湿活血方混悬液,给药共5周。治疗结束后,采用酶链免疫吸附法(ELISA)检测血清及肝组织乙型肝炎病毒表面抗原(HBsAg),采用常规苏木素—伊红(HE)染色观察肝组织病理变化,采用定量聚合酶链反应(qPCR)法检测血清中HBV DNA及肝组织中HBV DNA、TKB1 mRNA、IRF3 mRNA表达,采用蛋白免疫印迹(Western blot)法检测肝组织TKB1、IRF3的蛋白表达。【结果】标定14个特征峰构成清热利湿活血方的指纹图谱,其中1号峰为没食子酸,8号峰为柯里拉京,9号峰为虎杖苷,10号峰为鞣花酸,13号峰为甘草酸,14号峰为齐墩果酸。高剂量清热利湿活血方可减轻肝细胞轻度脂肪变性、肝细胞轻度水肿及Kuffer细胞增生等病理改变,显著降低HBV转基因小鼠肝脏和血清中的HBsAg、HBV DNA水平(P<0.05或P<0.01),显著增强小鼠TKB1、IRF3的mRNA及蛋白表达水平(P<0.05或P<0.01)。【结论】清热利湿活血方有抗HBV作用,其抗病毒机制可能与增强TKB1、IRF7 mRNA及蛋白表达,进而影响干扰素分泌有关。

福氏2a志贺菌DNA转录激活蛋白MarA的二级结构及其B细胞抗原表位预测

研究以福氏2a志贺菌(Shigella flexneri2a,s.f2a)的基因组序列为材料,采用Gamier-Robson法、Chou-Fasman法和Kamplus-Schulz法预测了其DNA结合转录激活蛋白MarA的二级结构,用Kyte-Doolittle法对结构蛋白的亲水性进行了分析,用Emini法预测了蛋白的表面可能性,以Jameson-Wolf法预测了蛋白的抗原指数,然后综合评价了福氏2a志贺菌转录激活蛋白MarA的B细胞抗原表位。结果表明:福氏2a志贺菌MarA蛋白的二级结构较为复杂,含有较多的转角和无规则卷曲等柔性区域以及α-螺旋和β-折叠区段,该蛋白有多处抗原指数较高的区段,其中含有潜在的B细胞优势抗原表位,因此其在免疫学中的地位也应当引起重视。

MANF brakes TLR4 signaling by competitively binding S100A8 with S100A9 to regulate macrophage phenotypes in hepatic fibrosis

The mesencephalic astrocyte-derived neurotrophic factor(MANF)has been recently identified as a neurotrophic factor,but its role in hepatic fibrosis is unknown.Here,we found that MANF was upregulated in the fibrotic liver tissues of the patients with chronic liver diseases and of mice treated with CCl4.MANF deficiency in either hepatocytes or hepatic mono-macrophages,particularly in hepatic mono-macrophages,clearly exacerbated hepatic fibrosis.Myeloid-specific MANF knockout increased the population of hepatic Ly6C^(high)macrophages and promoted HSCs activation.Furthermore,MANF-sufficient macrophages(from WT mice)transfusion ameliorated CCl4-induced hepatic fibrosis in myeloid cells-specific MANF knockout(MKO)mice.Mechanistically,MANF interacted with S100A8 to competitively block S100A8/A9 heterodimer formation and inhibited S100A8/A9-mediated TLR4-NF-κB signal activation.Pharmacologically,systemic administration of recombinant human MANF significantly alleviated CCl_(4)-induced hepatic fibrosis in both WT and hepatocytes-specific MANF knockout(HKO)mice.This study reveals a mechanism by which MANF targets S100A8/A9-TLR4 as a“brake”on the upstream of NF-κB pathway,which exerts an impact on macrophage differentiation and shed light on hepatic fibrosis treatment.

Osteoclast fusion and regulation by RANKL-dependent and independent factors

Osteoclasts are the bone resorbing cells essential for bone remodeling.Osteoclasts are formed from hematopoietic progenitors in the monocyte/macrophage lineage.Osteoclastogenesis is composed of several steps including progenitor survival,differentiation to mononuclear pre-osteoclasts,fusion to multi-nuclear mature osteoclasts,and activation to bone resorbing osteoclasts.The regulation of osteoclastogenesis has been extensively studied,in which the receptor activator of NF-κB ligand(RANKL)-mediated signaling pathway and downstream transcription factors play essential roles.However,less is known about osteoclast fusion,which is a property of mature osteoclasts and is required for osteoclasts to resorb bone.Several proteins that affect cell fusion have been identified.Among them,dritic cell-specific transmembrane protein(DC-STAMP)is directly associated to osteoclast fusion in vivo.Cytokines and factors influence osteoclast fusion through regula-tion of DC-STAMP.Here we review the recently discovered new factors that regulate osteoclast fusion with specific focus on DC-STAMP.A better understanding of the mechanistic basis of osteoclast fusion will lead to the development of a new therapeutic strategy for bone disorders due to elevated osteoclast bone resorption.Cell-cell fusion is essential for a variety of cellular biological processes.In mammals,there is a limited number of cell types that fuse to form multinucleated cells,such as the fusion of myoblasts for the formation of skeletal muscle and the fusion of cells of the monocyte/macrophage lineage for the formation of multinucleated osteoclasts and giant cells.In most cases,cellcell fusion is beneficial for cells by enhancing function.Myoblast fusion increases myofiber size and diameter and thereby increases contractile strength.Multinucleated osteoclasts have far more bone resorbing activity than their mono-nuclear counterparts.Multinucleated giant cells are much more efficient in the removal of implanted materials and bacteria due to chronic infection than macrophages.Therefore,they are also called foreign-body giant cells.Cell fusion is a complicated process involving cell migration,chemotaxis,cell-cell recognition and attachment,as well as changes into a fusion-competent status.All of these steps are regulated by multiple factors.In this review,we will discuss osteoclast fusion and regulation.

Immunomodulatory activity of polysaccharides from Brassica rapa by activating Akt/NF-κB signaling

Objective:To investigate the immunomodulatory activity of polysaccharides from the roots of Brassica rapa.Methods:The crude polysaccharide from roots of B.rapa(BRP)was extracted and purified to further investigate the active fraction of BRT for inducing macrophage phagocytosis.Results:Effects on RAW264.7 cells demonstrated that BRP behaved better phagocytic capacity and had potent immunomodulatory activity,including increasing production of nitric oxide(NO),tumor necrosis factor a(TNFa)and upregulating mRNA levels of inducible NO synthase(iNOS)and TNFa.Furthermore,modulation of macrophage by BRP was indicated to be mediated via the activation of Akt and nuclear factor-kappa B(NF-κB).Conclusion:The beneficial effects of BRP could be used as an immunotherapeutic adjuvant in treatment of inflammatory diseases.