圆盘状受体1在瘢痕疙瘩中的作用

目的:观察圆盘状受体1在瘢痕疙瘩不同部位的表达情况,进一步分析其在瘢痕疙瘩形成和发展中的作用。方法:选择2005-02/06在解放军第二军医大学附属长海医院门诊就诊的3例瘢痕疙瘩患者,均知情同意。瘢痕疙瘩事先均未进行任何治疗,将瘢痕疙瘩分为中央凹陷的老化部、隆起明显的增生部、表面潮红的浸润部及正常皮肤部。体外培养成纤维细胞,通过WESTBLOT实验检测瘢痕疙瘩不同部位圆盘状受体1、p53、基质金属蛋白酶表达情况,应用流式细胞仪检测细胞凋亡率。结果:①WESTBLOT实验检测结果:圆盘状受体1的表达以增生部、浸润部最明显,而老化部次之,正常皮肤部表达最弱。p53表达以老化部、增生部、浸润部为显著,正常皮肤部表达不显著。基质金属蛋白酶在老化部、增生部、浸润部表达强于正常皮肤部,而浸润部较老化部表达更强。②瘢痕疙瘩不同部位细胞凋亡率比较:正常皮肤部细胞凋亡率显著高于老化部及增生部[(10.1±3.5)%,(6.2±1.8)%,(5.1±3.7)%(P<0.05)],其中浸润部(4.6±3.4)%与正常皮肤部相比,差异具有极其显著性意义(P<0.01)。结论:在瘢痕疙瘩中表现出圆盘状受体1高表达及成纤维细胞低凋亡的特性,圆盘状受体1强表达区也有p53强表达,以上作用可保护细胞,防止细胞凋亡,而且有利于瘢痕疙瘩的浸润。     

5-氟尿嘧啶对瘢痕疙瘩成纤维细胞Smad7和转化生长因子βⅠ型受体表达的影响

背景:很多实验已证明5-氟尿嘧啶应用于瘢痕疙瘩治疗可收到良好的效果.但作者所查针对5-氟尿嘧啶经由转化生长因子β信号通路作用于瘢痕疙瘩分子机制的报道较少.目的:实验拟观察5-氟尿嘧啶对瘢痕疙瘩成纤维细胞Smad7和转化生长因子βⅠ型受体表达的影响.设计、时间及地点:细胞观察实验,于2007-02/10在安徽医科大学微生物教研室完成.材料:标本分别取自因瘢痕疙瘩入院的6例整形手术患者.方法:①瘢痕疙瘩组织成纤维细胞原代培养,取4～6代传代细胞加入5个不同浓度5-氟尿嘧啶(10,20,40,80,160 μmol/L)干预24,48,72 h.②待细胞长至80%汇合时,加入5-氟尿嘧啶配成10,20,30 μmol/L 3个药物干预浓度组,每组再加入转化生长因子β1继续培养.设空白对照和单纯加转化生长因子β1(5 μg/L)的阳性对照.主要观察指标:①利用四甲基偶氮唑盐法测定瘢痕疙瘩成纤维细胞的增殖能力.②蛋白免疫印迹检测各组瘢痕疙瘩成纤维细胞中Smad7和转化生长因子βⅠ型受体的表达.结果:①5-氟尿嘧啶浓度为10,20 μmol/L 作用24 h 时未发现成纤维细胞死亡,与空白对照组相比差异无显著性意义(P > 0.05);其他浓度下作用各组均有显著的成纤维细胞死亡现象(P < 0.01).②与空白对照组相比,转化生长因子β1组Smad7表达明显减弱,转化生长因子βⅠ型受体表达则显著增强(P均 < 0.01).③加入5-氟尿嘧啶干预后可显著增强Smad7的表达,且在5-氟尿嘧啶浓度为20 μmol/L 时的表达最强(P < 0.01).④不同浓度5-氟尿嘧啶对转化生长因子βⅠ型受体表达无明显影响.结论:5-氟尿嘧啶浓度为10～20 μmol/L 时无细胞毒性,与转化生长因子β1共同培养成纤维细胞,能够提高该细胞转化生长因子β1诱导的Smad7表达,但对于转化生长因子βⅠ型受体的表达没有明显影响.     

hTERT反义寡核苷酸对瘢痕疙瘩成纤维细胞增殖及端粒酶活性的影响

目的研究hTERT基因反义寡核苷酸(ASODN)对瘢痕疙瘩成纤维细胞生长增殖及端粒酶活性的抑制作用,探讨其在瘢痕疙瘩治疗中的作用。方法应用ASODN封闭瘢痕疙瘩成纤维细胞hTERT基因的表达,不同浓度不同时间以ASODN作用于体外培养的瘢痕疙瘩成纤维细胞,细胞计数和MTT法检测成纤维细胞生长增殖情况,端粒酶PCR-ELISA法检测不同处理浓度和时间成纤维细胞端粒酶活性。结果 ASODN作用于瘢痕疙瘩成纤维细胞72h后,成纤维细胞生长受抑,增殖能力减弱,并具有浓度、时间依赖性。端粒酶活性检测显示:ASODN0.5、1.0和1.5μmol/L作用组OD450-690值分别为0.612±0.038、0.535±0.027、0.423±0.023,与空白对照组(0.898±0.058)比较,差异有统计学意义(P<0.05);正义寡核苷酸1.0μmol/L作用组(OD450-690值为0.893±0.042)与空白对照组比较,差异无统计学意义(P>0.05)。结论 hTERT基因ASODN能抑制瘢痕疙瘩成纤维细胞的生长增殖,降低成纤维细胞端粒酶活性是其重要作用机制之一。通过抑制端粒酶活性进行抗瘢痕疙瘩治疗可能是一个新途径。     

结缔组织生长因子反义寡核苷酸对人增生性瘢痕成纤维细胞结缔组织生长因子表达及胶原合成的作用

目的:观察结缔组织生长因子反义寡核苷酸对转化生长因子β1诱导的人增生性瘢痕成纤维细胞结缔组织生长因子mRNA、蛋白的表达和胶原合成的影响。方法:实验于2005-03/12在哈尔滨医科大学免疫教研室完成。选取哈尔滨医科大学附属第二医院整形美容中心手术标本,包括正常皮肤和增生性瘢痕。将手术中切下的正常皮肤、增生性瘢痕组织在无菌条件下去除表皮后采用组织块贴壁法培养于含体积分数为0.1的胎牛血清的RPMI1640培养液中,置37℃,体积分数为0.05的CO2条件下原代培养。经2.5g/L胰蛋白酶消化传代,传代至3～5代时进行实验。实验分4组:①正常皮肤成纤维细胞组。②增生性瘢痕成纤维细胞组。③增生性瘢痕成纤维细胞 5.0mg/L转化生长因子β1组(简称转化生长因子β1组)。④增生性瘢痕成纤维细胞 5.0mg/L转化生长因子β1 结缔组织生长因子反义寡核苷酸组(简称反义寡核苷酸组)。用5.0mg/L转化生长因子β1刺激增生性瘢痕成纤维细胞后,以脂质体介导方法将结缔组织生长因子反义寡核苷酸转染增生性瘢痕成纤维细胞中,用反转录-聚合酶链反应方法和WesternBlot方法检测细胞中结缔组织生长因子mRNA和蛋白质的表达;采用3H-脯氨酸掺入法检测细胞的胶原合成量。结果:①反转录-聚合酶链反应结果:结缔组织生长因子mRNA在正常皮肤成纤维细胞中无表达,在增生性瘢痕成纤维细胞中表达增强,转化生长因子β1刺激后表达量0.64±0.32明显高于增生性瘢痕成纤维细胞0.31±0.14,差异显著(P<0.01);反义寡核苷酸组可以大部分抑制结缔组织生长因子mRNA的表达,表达量0.12±0.62明显低于增生性瘢痕成纤维细胞组和转化生长因子β1组,差异显著(P<0.01)。②Western印迹结果:蛋白水平趋势与mRNA水平相一致。结缔组织生长因子蛋白在正常皮肤成纤维细胞中无表达,在增生性瘢痕成纤维细胞中表达增强84.63±11.49,转化生长因子β1刺激后表达量102.89±14.35明显高于增生性瘢痕成纤维细胞组,差异显著(P<0.01);反义寡核苷酸组可以大部分抑制转化生长因子β1的作用,结缔组织生长因子蛋白表达量41.75±10.56低于增生性瘢痕成纤维细胞组和转化生长因子β1组(P<0.01)。③结缔组织生长因子反义寡核苷酸对增生性瘢痕成纤维细胞胶原合成的作用:增生性瘢痕成纤维细胞组、转化生长因子β1组、反义寡核苷酸组的3H-脯氨酸掺入率分别为5381±185,8273±357,2475±859,转化生长因子β1可以显著增加成纤维细胞胶原的合成(P<0.01);而结缔组织生长因子反义寡核苷酸对转化生长因子β1刺激后的成纤维细胞胶原合成有明显抑制作用,差异显著(P<0.01)。结论:结缔组织生长因子反义寡核苷酸能够抑制转化生长因子β1引起的结缔组织生长因子mRNA、蛋白质表达的增高和胶原合成的增多,表明阻断结缔组织生长因子可能是延缓瘢痕纤维化的有效手段。     

圆盘状受体1在瘢痕疙瘩中的作用

目的：观察圆盘状受体1在瘢痕疙瘩不同部位的表达情况，进一步分析其在瘢痕疙瘩形成和发展中的作用。 方法：选择2005-02／06在解放军第二军医大学附属长海医院门诊就诊的3例瘢痕疙瘩患者，均知情同意。瘢痕疙瘩事先均未进行任何治疗，将瘢痕疙瘩分为中央凹陷的老化部、隆起明显的增生部、表面潮红的浸润部及正常皮肤部。体外培养成纤维细胞，通过WESTBLOT实验检测瘢痕疙瘩不同部位圆盘状受体1、p53、基质金属蛋白酶表达情况，应用流式细胞仪检测细胞凋亡率。 结果：①WEST BLOT实验检测结果：圆盘状受体1的表达以增生部、浸润部最明显，而老化部次之，正常皮肤部表达最弱。p53表达以老化部、增生部、浸润部为显著，正常皮肤部表达不显著。基质金属蛋白酶在老化部、增生部、浸润部表达强于正常皮肤部，而浸润部较老化部表达更强。②瘢痕疙瘩不同部位细胞凋亡率比较：正常皮肤部细胞凋亡率显著高于老化部及增生部[（10．1&;#177;3．5）％，（6．2&;#177;1．8）％，（5．1&;#177;3．7）％（P〈0．05）]，其中浸润部（4．6&;#177;3．4）％与正常皮肤部相比，差异具有极其显著性意义（P〈0．01）。 结论：在瘢痕疙瘩中表现出圆盘状受体1高表达及成纤维细胞低凋亡的特性，圆盘状受体1强表达区也有p53强表达，以上作用可保护细胞，防止细胞凋亡，而且有利于瘢痕疙瘩的浸润。     

姜黄素对瘢痕疙瘩成纤维细胞胶原合成的影响

背景：近期研究提示姜黄素可能是一种抗纤维化制剂。目的：以瘢痕疙瘩成纤维细胞为靶细胞，观察不同浓度姜黄素对瘢痕疙瘩成纤维细胞合成胶原的影响。设计、时间及地点：随机对照实验，于2006-10／2007—11在懈放军第四军医大学西京医院烧伤与皮肤外科完成。材料：瘢痕疙瘩患者的手术标本5份，患者均知情同意。治疗方案经医院医学伦理委员会批准。姜黄素为美国Sigma公司产品。方法：瘢痕疙瘩成纤维细胞体外原代培养，待细胞融合后传代，取第3-6代对数生长期的成纤维细胞用于实验。将不同浓度姜黄素（5，10，20μmol／L）分别对瘢痕疙瘩成纤维细胞干预24～48h，以空白组做对照。主要观察指标：蛋白免疫印迹检测姜黄素作用瘢痕疙瘩成纤维细胞后结缔组织生长因子的表达。荧光定量聚合酶链反应检测姜黄素作用瘢痕疙瘩成纤维细胞后Ⅰ、Ⅲ型前胶原及结缔组织生长因子基因的表达。结果：①姜黄素作用瘢痕疙瘩成纤维细胞48h后，结缔组织生长因子蛋白的表达减少，均低于对照组（P〈0.01）。②与对照组相比，不同浓度姜黄素干预组Ⅰ、Ⅲ型前胶原及结缔组织生长因子表达均降低（P〈0．01），并且Ⅰ型前胶原表达随着药物浓度的增加，有逐渐降低的趋势，成明显的量效关系。姜黄素20μmol／L组Ⅲ型前胶原表达低于姜黄素10μmol／L组，但差异无显著性意义（P〉O．05），姜黄素10μmol／L组结缔组织生长因子表达低于姜黄素5μmol／L组，但差异无显著性意义（P〉0．05）。结论：姜黄素对体外培养的瘢痕疙瘩成纤维细胞胶原合成有明显抑制作用，其作用机制可能与姜黄素抑制结缔组织生长因子在瘢痕疙瘩成纤维细胞的表达有关。     

Ⅰ型和Ⅲ型前胶原基因核酶抑制增生性瘢痕的实验

目的:在细胞及动物体内证实前期已合成,并证实其活性的、针对I型和Ⅲ型前胶原基因的核酶的有效性。方法:实验于2004-01/08在中山大学附属第一医院烧伤科、中山大学附属第一医院外科实验室、广州市红十字会医院创伤研究所、中山大学医学院动物实验中心完成。选取80只SPF级4～6周龄裸鼠,体质量15～25g。随机分为注射Ⅰ型前胶原核酶A组、注射Ⅰ型前胶原核酶B组、注射Ⅲ型前胶原核酶C组、注射Ⅲ型前胶原核酶D组、注射Ⅲ型前胶原核酶E组、注射Ⅲ型前胶原核酶F组、对照组G组和空白对照组H组,每组10只。注射Ⅰ型及Ⅲ型前胶原核酶A-F组,7d。对照组G组注射生理盐水7d。应用苦味酸-天狼猩红染色偏振光法,观察分析各组胶原相对含量及分布的改变。同期选取增生性瘢痕来自烧伤愈后、瘢痕增生半年之患者手术切除标本。分为甲、乙、丙、丁、戊、己六种浓度组及空白对照组庚组。脂质体包裹核酶转染实验组培养细胞,测定培养上清羟脯氨酸含量、反转录多聚链反应法测量细胞内Ⅰ型和Ⅲ型胶原mRNA含量。结果:①细胞上清羟脯氨酸含量:甲-已组明显低于庚组(2.33±0.04,2.32±0.04,2.42±0.04,2.41±0.05,2.20±0.03,2.12±0.04,2.85±0.07)μg/L,P<0.01。②I型胶原mRNA表达甲-已组明显低于庚组:(0.796±0.034,0.834±0.017,0.860±0.026,0.838±0.023,0.842±0.031,0.858±0.037,0.940±0.037)μg/L,P<0.05。③Ⅲ型胶原蛋白mRNA表达:甲-已组明显低于庚组:(1.496±0.039,1.668±0.052,1.154±0.093,1.078±0.093,1.270±0.060,1.182±0.111,2.001±0.099)μg/L。④应用核酶前后瘢痕体积变化:A组、G组、H组实验前明显高于实验后[(28.31±2.10,25.60±1.20)(33.65±1.76,32.71±3.92)(29.53±2.50,28.80±2.71)mm3]。结论:所合成及扩增、转染的核酶可抑制人瘢痕成纤维细胞合成胶原,并能有效减少人增生性瘢痕裸鼠动物模型中瘢痕的胶原含量。     

几丁糖影响瘢痕疙瘩成纤维细胞胶原合成的机制

目的:探讨几丁糖对瘢痕疙瘩成纤维细胞功能的作用及机制,为临床应用几丁糖治疗瘢痕疙瘩提供理论基础。方法:以瘢痕疙瘩成纤维细胞为研究对象,正常皮肤成纤维细胞为对照,观察不同含量几丁糖对瘢痕疙瘩成纤维细胞合成分泌胶原量及其相应I型前胶原mRNA量的变化。结果:几丁糖作用后各组3H-脯氨酸掺入量均逐减少;瘢痕疙瘩组与正常皮肤组的减少率差别显著(χ2=11.3,P<0.05)。其相应I型前胶原mRNA量显著下降。结论:丁糖可以抑制瘢痕疙瘩成纤维细胞合成及分泌胶原的功能,有望在异常瘢痕的防治中发挥重要作用。     

血小板源生长因子受体在瘢痕疙瘩形成中的作用

目的:观察血小板源生长因子受体α和β在瘢痕疙瘩中的表达,并与正常皮肤比较。方法:实验于2005-04/10在解放军第二军医大学长海医院中心实验室进行。切取12例瘢痕疙瘩和6例正常皮肤标本,先经原代培养为成纤维细胞,取3～6代细胞分别应用免疫细胞化学和实时定量聚合酶链反应技术,检测瘢痕疙瘩成纤维细胞和正常皮肤成纤维细胞中血小板源生长因子受体α和血小板源生长因子受体β的蛋白和mRNA表达。结果:①免疫细胞化学结果:与正常皮肤相比,瘢痕疙瘩中的血小板源生长因子受体α和血小板源生长因子受体β的染色都增强,但血小板源生长因子受体α的染色增强尤其明显;图像分析定量统计显示瘢痕疙瘩中血小板源生长因子受体α的染色阳性指数显著高于正常皮肤(2.76±0.52,0.74±0.17,P<0.01),而血小板源生长因子受体β的染色阳性指数与正常皮肤比较差异不显著(0.95±0.202,0.76±0.17,P=0.07)。②实时定量聚合酶链反应结果:瘢痕疙瘩成纤维细胞中血小板源生长因子受体α的每百万看家基因含量显著高于正常皮肤(21.73±6.51,14.41±3.37,P=0.02),而血小板源生长因子受体β的每百万看家基因含量与正常皮肤比较差异不显著(P=0.06)。结论:在瘢痕疙瘩形成过程中,血小板源生长因子受体α的蛋白和mRNA表达都显著升高,可能是其病因机制之一。     

三七总甙对人瘢痕疙瘩成纤维细胞的作用

目的:观察三七总甙对体外培养的人瘢痕疙瘩成纤维细胞增殖及胶原合成的作用,以寻找治疗人瘢痕疙瘩的有效药物。方法:体外培养人瘢痕疙瘩成纤维细胞,分别应用噻唑蓝(MTT)比色法和H3-脯氨酸掺入法检测三七总甙作用后细胞增殖及胶原合成的变化。结果:与空白对照组相比,三七总甙含量在0.5,1.0和1.5g/L时均能够显著抑制成纤维细胞增殖及胶原合成(P<0.01),但在1.5g/L时对细胞具有毒性作用。结论:三七总甙具有体外抗纤维化作用,可能成为治疗瘢痕疙瘩的有效药物。     

The discoidin domain receptor tyrosine kinase DDR1 in arterial wound repair

Collagens act as important signaling molecules regulating vascular smooth muscle cell responses during arterial wound repair. Discoidin domain receptors (DDRs) are a novel class of receptor tyrosine kinases that bind to several collagens and stimulate matrix metalloproteinase (MMP) production, but little is known about their expression and function in the vasculature. We posited a critical role for the DDRs controlling smooth muscle cell migration and proliferation and thus repair following arterial injury. Smooth muscle cells were isolated from the aortas of mice with a targeted deletion of the DDR1 gene (DDR1-null) and studied in culture using models that mimic critical steps in neointimal thickening. Our studies suggest that DDR1 plays an important role in regulating attachment to collagen, chemotaxis, proliferation, and MMP production in smooth muscle cells. Following mechanical injury to the carotid arteries, cross-sectional area of the neointima was significantly lower in DDR1-null mice than in wild-type mice. There was also a significant decrease in collagen deposition in the injured arteries of the DDR1-null mice. Our results support the hypothesis that DDR1 plays an important role as a collagen receptor, mediating intimal thickening after vascular injury.     

Hyperbaric oxygen activates discoidin domain receptor 2 via tumour necrosis factor-alpha and the p38 MAPK pathway to increase vascular smooth muscle cell migration through matrix metalloproteinase 2

DDR2 (discoidin domain receptor 2) regulates collagen turnover mediated by SMCs (smooth muscle cells) in atherosclerosis. HBO (hyperbaric oxygen) has been used in medical practice; however, the molecular mechanism of the beneficial effects of HBO is poorly understood. Furthermore, the effect of HBO on DDR2 has not been reported previously. In the present study, we investigated the cellular and molecular mechanisms of DDR2 regulation by HBO in VSMCs (vascular SMCs). Cells were exposed to 2.5 ATA (atmosphere absolute) of oxygen in a hyperbaric chamber. DDR2 protein (3.63-fold) and mRNA (2.34-fold) expression were significantly increased after exposure to 2.5 ATA HBO for 1 h. Addition of SB203580 and p38 MAPK (mitogen-activated protein kinase) siRNA (small interfering RNA) 30 min before HBO inhibited the induction of DDR2 protein. HBO also significantly increased DNA-protein binding activity of Myc/Max. Addition of SB203580 and an anti-TNF-alpha (tumour necrosis factor-alpha) monoclonal antibody 30 min before HBO abolished the DNA-protein binding activity induced by HBO. HBO significantly increased the secretion of TNF-alpha from cultured VSMCs. Exogenous addition of TNF-alpha significantly increased DDR2 protein expression, whereas anti-TNF-alpha and anti-(TNF-alpha receptor) antibodies blocked the induction of DDR2 protein expression. HBO significantly increased VSMC migration and proliferation, whereas DDR2 siRNA inhibited the migration induced by HBO. HBO increased activated MMP2 (matrix metalloproteinase 2) protein expression, and DDR2 siRNA abolished the induction of activated MMP2 expression induced by HBO. In conclusion, HBO activates DDR2 expression in cultured rat VSMCs. HBO-induced DDR2 is mediated by TNF-alpha and at least in part through the p38 MAPK and Myc pathways.     

Immunoglobulin-like domain containing receptor 1 mediates fat-stimulated cholecystokinin secretion

Cholecystokinin (CCK) is a satiety hormone produced by discrete enteroendocrine cells scattered among absorptive cells of the small intestine. CCK is released into blood following a meal; however, the mechanisms inducing hormone secretion are largely unknown. Ingested fat is the major stimulant of CCK secretion. We recently identified a novel member of the lipoprotein remnant receptor family known as immunoglobulin-like domain containing receptor 1 (ILDR1) in intestinal CCK cells and postulated that this receptor conveyed the signal for fat-stimulated CCK secretion. In the intestine, ILDR1 is expressed exclusively in CCK cells. Orogastric administration of fatty acids elevated blood levels of CCK in wild-type mice but not Ildr1-deficient mice, although the CCK secretory response to trypsin inhibitor was retained. The uptake of fluorescently labeled lipoproteins in ILDR1-transfected CHO cells and release of CCK from isolated intestinal cells required a unique combination of fatty acid plus HDL. CCK secretion secondary to ILDR1 activation was associated with increased [Ca²⁺]_i, consistent with regulated hormone release. These findings demonstrate that ILDR1 regulates CCK release through a mechanism dependent on fatty acids and lipoproteins and that absorbed fatty acids regulate gastrointestinal hormone secretion.     

Gonococcal pili. Primary structure and receptor binding domain

The complete amino acid sequence of pilin from gonococcal strain MS11 and the sequence of constant and variable regions from strain R10 pilin have been determined in order to elucidate the structural basis for adherence function, antigenic diversity, and polymeric structure. The MS11 pilin sequence consists of 159 amino acids in a single polypeptide chain with two cysteines in disulfide linkage and serine-bonded phosphate residues. TC-2 (31-111), a soluble monomeric pilus peptide prepared by arginine-specific digestion, bound human endocervical, but not buccal or HeLa cells and therefore is postulated to encompass the receptor binding domain. Variable regions of CNBr-3 appear to confer antigenic diversity and comprise segments in which changes in the position of charged residues occur in hydrophilic, beta-turns. Residues 2-21 and 202-221 of gonococcal pilins and lower eucaryotic actins, respectively, exhibit 50% homology. When these residues are arranged at intervals of 100 degrees of arc on "helical wheels," the identical amino acids comprise a hydrophobic face on one side of the helix. This observation, the hydrophobic character of this region and the tendency for TC-1 (residues 1-30) to aggregate in water, suggest that this stretch interacts with other subunits to stabilize polymeric structure.     

核受体辅助抑制因子中ETO结合结构域的确定

目的 为消除急性髓系白血病标志基因AML1／ETO的活性，确定核受体辅助抑制因子（nuclear receptor co-repressor,N-CoR)与ETO基因相互作用的活性部位。方法 用PCR扩增不同区段的N－CoR(N-CoRY)，克隆入酵母表达质粒pGADGL中，构建获得pGADGL／N－CoRY。应用酵母双杂交技术及X-gal染以确定pGADGL／N－CoRY10个区段的N－CoR是否与ETO结合。结果 N－CoR的988－1126氨基酸残基与1551－1801氨基酸残基共存时，才能与ETO发生结合作用，是ETO相互作用的结构域。结论 N－CoR两个结构域能与ETO的两个锌指结构作用，保持两种蛋白之间的稳定结合。     

The B domain of coagulation factor VIII interacts with the asialoglycoprotein receptor

BACKGROUND: Coagulation factor VIII (FVIII) is a heavily glycosylated heterodimeric plasma protein that consists of a heavy (domains A1-A2-B) and light chain (domains A3-C1-C2). It has been well established that the clearance of FVIII from the circulation involves mechanisms that are sensitive to the low-density lipoprotein receptor (LDLR) family antagonist receptor-associated protein (RAP), including LDLR-related protein. Because FVIII clearance in the presence of a bolus injection of RAP still occurs fairly efficient, also RAP-independent mechanisms are likely to be involved. OBJECTIVES: In the present study, we investigated the interaction of FVIII with the endocytic lectin asialoglycoprotein receptor (ASGPR) and the physiological relevance thereof. METHODS AND RESULTS: Surface plasmon resonance studies demonstrated that FVIII dose-dependently bound to ASGPR with high affinity (Kd approximately 2 nM). FVIII subunits were different in that only the heavy chain displayed high-affinity binding to ASGPR. Studies employing a FVIII variant that lacks the B domain revealed that FVIII-ASGPR complex assembly is driven by structure elements within the B domain of the heavy chain. The FVIII heavy chain-ASGPR interaction required calcium ions and was inhibited by soluble D-galactose. Furthermore, deglycosylation of the FVIII heavy chain by endoglycosidase F completely abrogated the interaction with ASGPR. In clearance experiments in mice, the FVIII mean residence time was prolonged by the ASGPR-antagonist asialo-orosomucoid (ASOR). CONCLUSIONS: We conclude that asparagine-linked oligosaccharide structures of the FVIII B domain recognize the carbohydrate recognition domains of ASGPR and that an ASOR-sensitive mechanism, most likely ASGPR, contributes to the catabolism of coagulation FVIII in vivo.