• 【垂体切除术前后垂体依赖性高肾上腺皮质激素,皮质醇,α-黑素细胞刺激激素和生长激素的血浆谱。】 复制标题 收藏 收藏
    DOI:10.1677/joe.1.06782 复制DOI
    作者列表:Hanson JM,Kooistra HS,Mol JA,Teske E,Meij BP
    BACKGROUND & AIMS: :The 6-h plasma profiles of adrenocorticotropic hormone (ACTH), cortisol, alpha-melanocyte-stimulating hormone (alpha-MSH), and GH were studied in 17 dogs with pituitary-dependent hyperadrenocorticism (PDH) before and after hypophysectomy. The aim of the study was to investigate the relation between the hormone profile characteristics and recurrence of PDH after surgery. The hormones were secreted in a pulsatile fashion. The basal plasma cortisol concentration and area under the curve (AUC) for cortisol were significantly higher in the PDH cases than in eight controls. The characteristics of the plasma profiles of ACTH and alpha-MSH were not significantly different between the PDH cases and the controls. In the PDH cases, less GH was secreted in pulses than in the controls, but the difference was not significant. The basal plasma cortisol concentration, the AUC for ACTH and cortisol, and the pulse frequency of ACTH and cortisol decreased significantly after hypophysectomy for the group of PDH cases. The basal plasma concentrations of ACTH and alpha-MSH, the AUC for alpha-MSH, and the characteristics of the plasma GH profiles of the PDH cases remained unchanged after hypophysectomy. No pulses of alpha-MSH were observed after hypophysectomy. The co-occurrence between the ACTH and cortisol pulses decreased significantly with hypophysectomy. The postoperative pulse frequency of ACTH was the only characteristic with predictive value for the recurrence of PDH after hypophysectomy. The results of this study demonstrate that ACTH, cortisol, alpha-MSH, and GH are secreted in a pulsatile fashion in dogs with PDH. Hypophysectomy effectively reduces the secretion of ACTH and cortisol. The presence of ACTH pulses after hypophysectomy is a risk factor for the recurrence of hyperadrenocorticism.
    背景与目标: : 在17只垂体切除术前后,研究了促肾上腺皮质激素 (ACTH),皮质醇,α-黑素细胞刺激激素 (alpha-MSH) 和GH的6小时血浆谱。该研究的目的是研究PDH术后激素特征与复发之间的关系。荷尔蒙以脉动的方式分泌。PDH病例的基础血浆皮质醇浓度和皮质醇曲线下面积 (AUC) 显着高于八个对照。在PDH病例和对照组之间,ACTH和 α-MSH的血浆特征没有显着差异。在PDH病例中,脉冲分泌的GH比对照组少,但差异不显着。PDH组患者垂体切除术后,基础血浆皮质醇浓度,ACTH和皮质醇的AUC以及ACTH和皮质醇的脉冲频率显着降低。垂体切除术后,PDH病例的基础血浆ACTH和 α-MSH的血浆浓度,α-MSH的AUC以及血浆GH谱的特征保持不变。垂体切除术后未观察到 α-MSH脉冲。垂体切除术后,ACTH和皮质醇脉冲之间的共存显着减少。ACTH的术后脉搏频率是垂体切除术后PDH复发的唯一特征,具有预测价值。这项研究的结果表明,患有PDH的狗以脉动方式分泌ACTH,皮质醇,α-MSH和GH。垂体切除术有效地减少了ACTH和皮质醇的分泌。垂体切除术后ACTH脉冲的存在是肾上腺皮质亢进症复发的危险因素。
  • 【燕麦花粉管壁的生长。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Dickinson HG,Lawson J
    BACKGROUND & AIMS: :The growth of the pollen tube wall of Oenothera is effected by the expulsion of fibrillar material from the cytoplasm into the developing wall. This material may also be seen in the cytoplasm, contained in membrane-bound vesicles. It is not clear how the content of the vesicles is discharged, but it appears not to involve the participation of microtubules. The source of the cytoplasmic fibrillar bodies depends upon the stage of development of the pollen tube. The earilest growth is derived from the inclusion into the wall of vesicles containing pre-formed materials present in the grain on pollination. During the next stage of growth the wall is derived from the content of double-membraned inclusions also present in the pollen. The content of the former vesicles is not so similar to the wall as the latter, but intermediates between the 2 types of vesicle may be seen in the cytoplasm, indicating that the former are formed from the latter. Most of the tube wall is derived from the products of dictyosomes in the pollen grain or tube. These dicytosomes are few in number and they must be exceedingly active. This, and the observation that dictyosome vesicles are frequently associated with banked complexes of mitochondria, indicates that some steps in the metabolism of the vesicular content, perhaps phosphorylation, take place distant from the dicytosomes. These different sources of fibrillar material presumably permit the rapid starting of tube growth, without any attendant metabolism. However, it would be impossible to include enough pre-formed wall material in the grain to enable the full growth of the tube, so once started, it seems that the tube then relies on the elaboration of simple reserves for the contruction of its wall. These reserves are likely to be held in the pollen, and may be the large numbers of starch grains characteristic of the pollen cytoplasm.
    背景与目标: : 卵生花粉管壁的生长是通过将原纤维物质从细胞质中排出到发育中的壁中而实现的。这种物质也可以在细胞质中看到,包含在膜结合的囊泡中。尚不清楚如何释放囊泡的含量,但似乎不涉及微管的参与。细胞质原纤维体的来源取决于花粉管的发育阶段。最早的生长来自包含在授粉时谷物中存在的包含预形成材料的囊泡壁。在生长的下一阶段,壁来自花粉中也存在的双层包裹体的含量。前者囊泡的含量不像后者那样与壁相似,但在细胞质中可能看到2种囊泡之间的中间体,表明前者是由后者形成的。大部分的管壁来源于花粉粒或管中双子体的产物。这些二胞体数量很少,它们必须非常活跃。这以及观察到dictyosome囊泡经常与线粒体的银行复合物有关,这表明囊泡含量代谢的某些步骤 (可能是磷酸化) 发生在远离二胞体的地方。这些不同的原纤维物质来源可能允许快速开始管生长,而没有任何伴随的代谢。但是,不可能在谷物中包括足够的预成型壁材料以使管完全生长,因此一旦开始,管似乎就依赖于简单的储备来构造其壁。这些储备很可能存在于花粉中,并且可能是花粉细胞质特有的大量淀粉粒。
  • 【内源性BDNF和NT-3在调节皮质树突生长中的相反作用。】 复制标题 收藏 收藏
    DOI:10.1016/s0896-6273(00)80316-5 复制DOI
    作者列表:McAllister AK,Katz LC,Lo DC
    BACKGROUND & AIMS: :Neurons within each layer of cerebral cortex express multiple members of the neurotrophin family and their corresponding receptors. This multiplicity could provide functional redundancy; alternatively, different neurotrophins may direct distinct aspects of cortical neuronal growth and differentiation. By neutralizing endogenous neurotrophins in organotypic slices of developing cortex with Trk receptor bodies (Trk-IgGs), we found that BDNF and NT-3 oppose one another in regulating the dendritic growth of pyramidal neurons. In layer 4, both endogenous and exogenous NT-3 inhibited the dendritic growth stimulated by BDNF. In contrast, in layer 6 both endogenous and exogenous BDNF inhibited dendritic growth stimulated by NT-3. These antagonistic actions of endogenous BDNF and NT-3 provide a mechanism by which dendritic growth and retraction can be dynamically regulated during cortical development, and suggest that the multiple neurotrophins expressed in developing cortex represent distinct components of an extracellular signaling system for regulating dendritic growth.
    背景与目标: : 大脑皮层各层内的神经元表达神经营养蛋白家族的多个成员及其相应的受体。这种多样性可以提供功能冗余; 或者,不同的神经营养蛋白可能会指导皮质神经元生长和分化的不同方面。通过用Trk受体体 (Trk-igg) 中和发育中的皮层器官型切片中的内源性神经营养蛋白,我们发现BDNF和NT-3在调节锥体神经元的树突状生长方面相互对抗。在第4层中,内源性和外源性NT-3均抑制BDNF刺激的树突状生长。相反,在第6层中,内源性和外源性BDNF均抑制NT-3刺激的树突生长。内源性BDNF和NT-3的这些拮抗作用提供了一种机制,通过该机制可以在皮质发育过程中动态调节树突生长和收缩,并表明在发育中的皮质中表达的多种神经营养蛋白代表了调节树突生长的细胞外信号系统的不同成分。
  • 【低氧下肿瘤-基质细胞相互作用通过肝细胞生长因子/c-Met途径增加胰腺癌细胞的侵袭性。】 复制标题 收藏 收藏
    DOI:10.1002/ijc.22178 复制DOI
    作者列表:Ide T,Kitajima Y,Miyoshi A,Ohtsuka T,Mitsuno M,Ohtaka K,Koga Y,Miyazaki K
    BACKGROUND & AIMS: :The hypoxic environment in tumor is reported to play an important role in pancreatic cancer progression. The interaction between stromal and cancer cells also contributes to the malignant behavior of pancreatic cancer. In the present study, we investigated whether hypoxic stimulation affects stromal as well as pancreatic cancer cells. Our findings demonstrated that hypoxia remarkably elevated the HIF-1alpha expression in both pancreatic cancer (PK8) and fibroblast cells (MRC5). Hypoxic stimulation accelerated the invasive activity of PK8 cells, and invasiveness was thus further accelerated when the hypoxic PK8 cells were cultured with conditioned medium prepared from hypoxic MRC5 cells (hypoxic conditioned medium). MMP-2, MMP-7, MT1-MMP and c-Met expressions were increased in PK8 cells under hypoxia. Hypoxic stimulation also increased the hepatocyte growth factor (HGF) secretion from MRC5 cells, which led to an elevation of c-Met phosphorylation in PK8 cells. Conversely, the elevated cancer invasion, MMP activity and c-Met phosphorylation of PK8 cells were reduced by the removal of HGF from hypoxic conditioned medium. In immunohistochemical study, the HIF-1alpha expression was observed in surrounding stromal as well as pancreatic cancer cells, thus indicating hypoxia exists in both of cancer and stromal cells. Moreover, the stromal HGF expression was found to significantly correlate with not only the stromal HIF-1alpha expression but also the c-Met expression in cancer cells. These results indicate that the hypoxic environment within stromal as well as cancer cells activates the HGF/c-Met system, thereby contributing to the aggressive invasive features of pancreatic cancer.
    背景与目标: : 据报道,肿瘤中的低氧环境在胰腺癌的进展中起重要作用。基质细胞和癌细胞之间的相互作用也有助于胰腺癌的恶性行为。在本研究中,我们调查了缺氧刺激是否会影响基质细胞以及胰腺癌细胞。我们的发现表明,缺氧显着提高了胰腺癌 (PK8) 和成纤维细胞 (MRC5) 的HIF-1alpha表达。低氧刺激加速了PK8细胞的侵袭活性,因此,当用低氧MRC5细胞制备的条件培养基 (低氧条件培养基) 培养低氧PK8细胞时,其侵袭能力进一步加快。缺氧条件下PK8细胞MMP-2、MMP-7、MT1-MMP和c-Met表达增加。低氧刺激还增加了MRC5细胞的肝细胞生长因子 (HGF) 分泌,导致PK8细胞中c-Met磷酸化升高。相反,通过从低氧条件培养基中去除HGF,可以降低PK8细胞的癌症侵袭,MMP活性和c-Met磷酸化水平。在免疫组织化学研究中,在周围基质以及胰腺癌细胞中观察到HIF-1alpha表达,因此表明癌症和基质细胞中都存在缺氧。此外,发现基质HGF表达不仅与癌细胞中的基质HIF-1alpha表达显着相关,而且与c-Met表达显着相关。这些结果表明,基质和癌细胞内的缺氧环境激活了HGF/c-Met系统,从而有助于胰腺癌的侵袭性特征。
  • 【产气荚膜梭菌的 α 毒素不是鸡坏死性肠炎的必需毒力因子。】 复制标题 收藏 收藏
    DOI:10.1128/IAI.00806-06 复制DOI
    作者列表:Keyburn AL,Sheedy SA,Ford ME,Williamson MM,Awad MM,Rood JI,Moore RJ
    BACKGROUND & AIMS: :The Clostridium perfringens alpha-toxin has previously been implicated as the major virulence factor in necrotic enteritis in chickens, although definitive proof has not been reported. In this study an alpha-toxin mutant was constructed in a virulent chicken isolate and shown to retain full virulence in a chicken disease model. These results demonstrated that alpha-toxin is not an essential virulence factor in the pathogenesis of necrotic enteritis in chickens.
    背景与目标: : 尽管尚未报道明确的证据,但以前曾将产气荚膜梭菌 α 毒素作为鸡坏死性肠炎的主要毒力因子。在这项研究中,在强毒鸡分离株中构建了一个 α 毒素突变体,并显示在鸡疾病模型中保留了完全的毒力。这些结果表明,在鸡坏死性肠炎的发病机理中,α-毒素不是必需的毒力因子。
  • 【伴刀豆球蛋白A (而不是糖化白蛋白) 在体外增加了血管性血友病因子的内皮下沉积。】 复制标题 收藏 收藏
    DOI:10.1080/10623320600903916 复制DOI
    作者列表:Nizheradze K
    BACKGROUND & AIMS: :Diabetes is associated with augmentation of prothrombogenic von Willebrand factor (vWF) content in plasma. Earlier, the author and colleagues have shown that high glucose and insulin do not appreciably influence deposition of vWF into the subendothelial extracellular matrix (SECM) produced by cultured human umbilical vein endothelial cells (HUVECs). In the present work, the author used this model to test the effects of nonenzymatically glycated albumin (Glyc-HSA) and two lectins, concanavalin A (ConA) and wheat germ agglutinin (WGA), on vWF deposition into the SECM. First-passage HUVECs were seeded into gelatin-coated 96-well plates and cultured for 6 to 7 days. HSA or Glyc-HSA (at concentrations 25, 50, and 100 microg/mL), and WGA or ConA (4, 8, and 16 microg/mL) were added 3 h after seeding. Cell viability was tested by the MTT method. To determine vWF contents in the SECM, HUVECs were detached by treatment with NH4OH and the residual material was used as a solid phase in an enzyme-linked immunosorbent assay (ELISA)-like assay with primary (anti-vWF) and secondary (peroxidase-conjugated) antibodies. Addition of Glyc-HSA did not essentially influence VWF contents in the SECM (A490 was 0.226 versus 0.268 at 0 and 100 microg/mL, respectively; p > .05, n = 16). Cultivation in the presence of WGA led to the deterioration of cell viability, which was accompanied by a significant decrease of vWF in the SECM (0.248 versus 0.128 at 0 and 16 microg/mL, respectively; p < .001, n = 16). ConA did not influence viability of HUVECs, but this lectin at all concentrations consistently increased the deposition of vWF (up to 164% relative to control, p <.001; n = 16). These data indicate that endothelial carbohydrate determinants and corresponding ligands (namely, mannose-specific lectins) may be involved in the regulation of production and deposition of vWF.
    背景与目标: : 糖尿病与血浆中血栓形成原性血管性假血友病因子 (vWF) 含量增加有关。早些时候,作者和同事已经表明,高糖和胰岛素不会明显影响vWF在培养的人脐静脉内皮细胞 (huvec) 产生的内皮下细胞外基质 (SECM) 中的沉积。在当前工作中,作者使用该模型测试了非酶促糖化白蛋白 (Glyc-HSA) 和两种凝集素,伴刀豆球蛋白A (ConA) 和小麦胚芽凝集素 (WGA) 对vWF沉积到SECM中的影响。将首次通过的huvec接种到明胶涂层的96孔板中,并培养6至7天。接种后3小时加入HSA或Glyc-HSA (浓度为25、50和100微克/毫升) 和WGA或ConA (4、8和16微克/毫升)。通过MTT方法测试细胞活力。为了确定SECM中的vWF含量,通过用NH4OH处理分离HUVECs,并将残留的物质用作一级 (抗-vWF) 和二级 (过氧化物酶结合的) 抗体的酶联免疫吸附测定 (ELISA) 样测定的固相。添加Glyc-HSA基本上不影响SECM中的VWF含量 (分别在0和100微克/毫升时A490为0.226对0.268; p> .05,n = 16)。在WGA存在下的培养导致细胞活力的恶化,其伴随着SECM中vWF的显著降低 (分别在0和16微克/毫升时0.248对0.128; p <.001,n = 16)。ConA不影响huvec的生存能力,但是在所有浓度下,这种凝集素始终增加vWF的沉积 (相对于对照高达164%,p <.001; n = 16)。这些数据表明,内皮碳水化合物决定簇和相应的配体 (即甘露糖特异性凝集素) 可能参与了vWF产生和沉积的调节。
  • 【注意缺陷多动障碍可能与中枢脑源性神经营养因子活性降低有关: 临床和治疗意义。】 复制标题 收藏 收藏
    DOI:10.1016/j.mehy.2006.06.025 复制DOI
    作者列表:Tsai SJ
    BACKGROUND & AIMS: :Attention-deficit hyperactivity disorder (ADHD) is a common childhood psychiatric disorder. Despite intensive research efforts, the aetiology of ADHD remains unknown. Current evidence suggests that the aetiology of ADHD is heterogeneous, comprising of multiple factors. Recently, it has been proposed that brain-derived neurotrophic factor (BDNF), a member of the neurotrophic factor family, may be implicated in the pathogenesis of ADHD. This hypothesis is supported by recent genetic studies in ADHD. Drawing on findings from studies into the drugs for ADHD relating to central BDNF expression, hyperactivity in BDNF knockout mice, BDNF effects in midbrain dopaminergic function and the close association between BDNF and the dopamine transporter (an important molecule for ADHD pathogenesis), it is proposed here that decreased central BDNF, particularly in the midbrain region, may play an important role in the pathogenesis ADHD. This hypothesis may have some implications for clinical findings in ADHD (for example, the co-morbidity between ADHD and major depression), and provide a new direction for the development of medication for ADHD treatment.
    背景与目标: : 注意力缺陷多动障碍 (ADHD) 是一种常见的儿童精神疾病。尽管进行了大量研究,但ADHD的病因仍然未知。目前的证据表明,ADHD的病因是异质的,由多种因素组成。最近,有人提出,神经营养因子家族的成员脑源性神经营养因子 (BDNF) 可能与ADHD的发病机理有关。该假设得到了ADHD最近的遗传研究的支持。根据对ADHD药物的研究结果,该药物与中枢BDNF表达,BDNF基因敲除小鼠的活动过度,BDNF在中脑多巴胺能功能中的作用以及BDNF与多巴胺转运蛋白 (ADHD发病机理的重要分子) 之间的密切联系有关,在这里提出降低中枢BDNF,特别是在中脑区域,可能在ADHD的发病机理中起重要作用。该假设可能对ADHD的临床发现 (例如,ADHD与重度抑郁症之间的合并症) 具有一定的意义,并为ADHD治疗药物的发展提供了新的方向。
  • 【组成型CD40信号表型发挥了爱泼斯坦-巴尔病毒癌蛋白LMP1的体外转化功能。】 复制标题 收藏 收藏
    DOI:10.1016/j.leukres.2006.06.023 复制DOI
    作者列表:Hatzivassiliou EG,Kieff E,Mosialos G
    BACKGROUND & AIMS: :The oncoprotein LMP1 mimics an activated CD40 receptor, yet it is not known whether constitutive CD40 signaling, like LMP1, is sufficient to transform cells. Here we demonstrate that constitutive activation of the CD40 pathway by a chimeric LMP1CD40 molecule resembles the transforming function of LMP1 in inducing loss of contact inhibition and anchorage independent growth of Rat1 fibroblasts. Rat1 transformation correlates with the expression level of LMP1CD40 and depends on its ability to oligomerize. Our data provide direct evidence for the oncogenic potential of the CD40 signaling pathway, which is also established as a model-mechanism for LMP1-induced transformation.
    背景与目标: : 癌蛋白LMP1模仿活化的CD40受体,但尚不清楚组成型CD40信号传导 (如LMP1) 是否足以转化细胞。在这里,我们证明了嵌合LMP1CD40分子对CD40途径的组成型激活类似于LMP1在诱导Rat1成纤维细胞的接触抑制丧失和锚定独立生长方面的转化功能。Rat1转化与LMP1CD40的表达水平相关,并取决于其寡聚能力。我们的数据为CD40信号通路的致癌潜力提供了直接证据,CD40信号通路也被确立为LMP1-induced转化的模型机制。
  • 【具有组蛋白H1-like羧基末端结构域的原核调节因子: algP内重复序列的克隆变异,该基因参与铜绿假单胞菌粘液样的调节。】 复制标题 收藏 收藏
    DOI:10.1128/jb.172.10.5544-5554.1990 复制DOI
    作者列表:Deretic V,Konyecsni WM
    BACKGROUND & AIMS: :A novel procaryotic transcriptional regulatory element, AlgP, with a histone H1-like carboxy-terminal domain was identified in Pseudomonas aeruginosa. AlgP is required for transcription of the key biosynthetic gene algD, which is necessary for production of the exopolysaccharide alginate causing mucoidy in P. aeruginosa. Mucoidy is a critical virulence determinant of P. aeruginosa invariably associated with the respiratory infections causing high mortality in cystic fibrosis. Here we show that AlgP and histones H1 both have repeated units of the Lys-Pro-Ala-Ala motif (KPAA) and its variations within their long (over 100 amino acids) carboxy-terminal domains. This region of histone H1 tails has been shown to bind to the linker DNA in eucaryotic chromatin fibers. A synthetic 50-mer peptide consisting of repeats from the AlgP carboxy-terminal domain was found to bind DNA in a mobility shift DNA-binding assay. AlgP is encoded by a gene that contains multiple direct repeats organized as tandem, head-to-tail, 12-base-pair (bp) units overlapping with six highly conserved 75-bp units. The repetitive structure of the algP gene appears to participate in the processes underlying the metastable character of mucoidy in P. aeruginosa. Relatively large DNA rearrangements spanning the region with tandem direct repeats encoding the carboxy-terminal histone H1-like structure of AlgP were detected in several strains upon conversion from the mucoid to the nonmucoid phenotype. The frequency of the detectable algP rearrangements associated with the transition into the nonmucoid state varied from strain to strain and ranged from 0 to 50%. The nonmucoid derivatives with the clearly rearranged chromosomal copy of algP were complemented to mucoidy with plasmids containing algP from P. aeruginosa PAO. When a random collection of mucoid strains, isolated from different cystic fibrosis patients, was analyzed by using polymerase chain reaction, an additional level of strain-dependent sequence variation in algP was observed. Variations in the number of the 12-bp repeats were found; however, they did not appear to influence the mucoid status of the strains examined. Thus, the repeated region of algP appears to be a hot spot for DNA rearrangements and strain-dependent variability.
    背景与目标: : 在铜绿假单胞菌中鉴定了一种新型的原核转录调节元件AlgP,其具有组蛋白H1-like羧基末端结构域。AlgP是关键生物合成基因algD转录所必需的,这对于产生引起铜绿假单胞菌粘液的胞外多糖藻酸盐是必需的。粘液症是铜绿假单胞菌的关键毒力决定因素,总是与导致囊性纤维化高死亡率的呼吸道感染相关。在这里,我们显示了AlgP和组蛋白H1都具有Lys-Pro-Ala基序 (KPAA) 的重复单元及其在其长 (超过100个氨基酸) 羧基末端结构域中的变化。已显示组蛋白H1尾巴的该区域与真核染色质纤维中的接头DNA结合。在迁移率转移DNA结合试验中,发现由来自AlgP羧基末端结构域的重复序列组成的合成50聚体肽结合DNA。AlgP由一个基因编码,该基因包含多个直接重复序列,组织为串联,头对尾,12碱基对 (bp) 单元,与六个高度保守的75 bp单元重叠。algP基因的重复结构似乎参与了铜绿假单胞菌黏液的亚稳态特征的潜在过程。从粘液样转化为非粘液样表型后,在几个菌株中检测到跨越编码AlgP羧基末端组蛋白H1-like结构的串联直接重复序列的区域的相对较大的DNA重排。与过渡到非粘液状态相关的可检测的algP重排的频率因菌株而异,范围为0至50%。具有明显重排的algP染色体拷贝的非粘液衍生物与含有铜绿假单胞菌PAO的algP的质粒互补为粘液。当使用聚合酶链反应分析从不同的囊性纤维化患者中分离出的粘液样菌株的随机集合时,观察到algP中菌株依赖性序列变异的额外水平。发现12 bp重复序列的数量有所变化; 但是,它们似乎并未影响所检查菌株的粘液状态。因此,algP的重复区域似乎是DNA重排和应变依赖性变异性的热点。
  • 【转化生长因子-β: 血管生成、血管生成和血管壁完整性。】 复制标题 收藏 收藏
    DOI:10.1016/s1359-6101(96)00048-2 复制DOI
    作者列表:Pepper MS
    BACKGROUND & AIMS: Genetic studies have recently revealed a role for transforming growth factor-beta-1 (TGF-beta 1) and its receptors (TGF-beta Rs I and II as well as endoglin) in embryonic vascular assembly and in the establishment and maintenance of vessel wall integrity. The purpose of this review is threefoldfirst, to reassess previous studies on TGF-beta and endothelium in the light of these recent findings; second, to describe some of the well-established as well as controversial issues concerning TGF-beta and its regulatory role in angiogenesis; and third, to explore the notion of "context' with respect to TGF-beta and endothelial cell function. Although the focus of this review will be on the endothelium, other vascular wall cells are also likely to be important in the pathogenesis of the vascular lesions revealed by genetic studies.

    背景与目标: 遗传研究最近揭示了转化生长因子-beta-1 (TGF-beta 1) 及其受体 (TGF-beta Rs I和II以及endoglin) 在胚胎血管组装以及血管壁完整性的建立和维持中的作用。这篇综述的目的是三重首先,根据这些最新发现重新评估先前关于TGF-β 和内皮的研究; 第二,描述一些关于TGF-β 及其在血管生成中的调节作用的公认的和有争议的问题; 第三,探讨TGF-β 和内皮细胞功能的 “背景” 概念。尽管本综述的重点将放在内皮上,但其他血管壁细胞也可能在遗传学研究揭示的血管病变的发病机理中很重要。
  • 【人冠状动脉粥样斑块切除术中肝细胞生长因子的免疫组织化学分析: 与转化生长因子 β 亚型的比较。】 复制标题 收藏 收藏
    DOI:10.1007/s004280050050 复制DOI
    作者列表:Ueda H,Imazu M,Hayashi Y,Ono K,Yasui W,Yamakido M
    BACKGROUND & AIMS: The expression and localization of hepatocyte growth factor/scatter factor (HGF/SF) were examined immunohistochemically in 59 human coronary artery lesions retrieved by directional coronary atherectomy and compared with the localization of transforming growth factor beta isoforms (TGF-beta 1, -beta 2, and -beta 3). In 21 of the 59 specimens (35.6%) HGF-like immunoreactivity (HGF-IR) was revealed. The HGF immunopositivity rate of 45% (14/31) in thrombotic tissue was significantly (P < 0.05) higher than the rates of 7.3% (4/55), 7.1% (3/42), and 0% (0/14) in fibrous tissue, neointimal hyperplasia and atheromatous gruel, respectively. Immunoreactivity for HGF was much weaker than that for TGF-beta isoforms in these components except in thrombotic tissue. These cells exhibiting strong HGF-IR were inflammatory cells such as monocytes/macrophages in thrombotic tissue, in tissue lesions adjacent to a thrombus, and outside the capillary walls in a portion of the neovascularized lesions. Smooth muscle cells (SMCs) hardly demonstrated HGF-IR. In contrast, in control coronary arteries obtained at autopsy, the HGF-IR was strongly expressed in SMCs. These findings suggest that HGF produced by macrophages play a part in the process of coronary plaque formation attributable to thrombus in man.

    背景与目标: 通过免疫组织化学检查了通过定向冠状动脉粥样斑块切除术检索的59例人冠状动脉病变中肝细胞生长因子/散射因子 (HGF/SF) 的表达和定位,并将其与转化生长因子 β 亚型 (tgf-β1,-β2和-β3) 的定位进行了比较。在59个标本中的21个 (35.6%) 中,HGF样免疫反应性 (hgf-ir) 被揭示。血栓组织中45% (14/31) 的HGF免疫阳性率显着 (P < 0.05) 高于纤维组织,新内膜增生和动脉粥样硬化稀粥中的7.3% (4/55),7.1% (3/42) 和0% (0/14)。分别。除血栓形成组织外,这些成分中HGF的免疫反应性比TGF-β 同工型的免疫反应性弱得多。这些表现出强hgf-ir的细胞是炎性细胞,例如血栓形成组织中,与血栓相邻的组织病变以及部分新生血管病变的毛细血管壁外部的单核细胞/巨噬细胞。平滑肌细胞 (smc) 几乎不显示HGF-IR。相反,在尸检获得的对照冠状动脉中,hgf-ir在smc中强烈表达。这些发现表明,巨噬细胞产生的HGF在人类血栓形成引起的冠状动脉斑块形成过程中发挥了作用。
  • 【吗啡刺激小鼠视网膜内皮细胞血管内皮生长因子样信号传导。】 复制标题 收藏 收藏
    DOI:10.2174/156720206778018767 复制DOI
    作者列表:Chen C,Farooqui M,Gupta K
    BACKGROUND & AIMS: :Go/Gi coupled G-protein receptor mediated transactivation is critical in the activation of receptor tyrosine kinases (RTK). Here we show that mu opioid receptor (MOR) transactivates Flk1 and platelet-derived growth factor-beta (PDGF-beta) receptors and its agonist morphine stimulates pro-angiogenic and survival-promoting signaling in mouse retinal endothelial cells (mREC). Morphine stimulates mREC proliferation in a dose dependent fashion and promotes survival to the same extent as vascular endothelial growth factor164 (VEGF164). Morphine stimulates mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) and Akt phosphorylation in a time dependent manner like VEGF in mREC. Moreover, analogous to VEGF, morphine stimulates oncogenic signal transducer and activator of transcription 3 (STAT3) signaling. Morphine as well as VEGF-induced phospho-STAT3 and phospho-Flk1 immunoprecipitated with MOR-associated proteins. In addition morphine also stimulated MOR associated PDGF-beta receptor phosphorylation. Consistent with the relationship between VEGF and MOR we found that VEGF upregulates MOR protein and RNA expression in mREC. These data suggest that MOR associates and transactivates RTKs for Flk1 and PDGF-beta, which may have a compounding effect on angiogenic signaling in endothelium. Therefore, G-Protein coupled receptors including MOR provide novel targets to develop anti-angiogenic agents.
    背景与目标: : Go/Gi偶联的g蛋白受体介导的反式激活在受体酪氨酸激酶 (RTK) 的激活中至关重要。在这里,我们显示mu阿片受体 (MOR) 反式激活Flk1和血小板衍生的生长因子-β (pdgf-β) 受体及其激动剂吗啡刺激小鼠视网膜内皮细胞 (mREC) 中的促血管生成和促进存活的信号。吗啡以剂量依赖性方式刺激mREC增殖,并以与血管内皮生长因子164 (VEGF164) 相同的程度促进存活。吗啡以时间依赖性方式刺激丝裂原激活的蛋白激酶/细胞外信号调节激酶 (MAPK/ERK) 和Akt磷酸化,如mREC中的VEGF。此外,与VEGF类似,吗啡刺激致癌信号转导和转录激活因子3 (STAT3) 信号传导。吗啡以及VEGF诱导的phospho-STAT3和phospho-Flk1用MOR相关蛋白免疫沉淀。此外,吗啡还刺激MOR相关的PDGF-β 受体磷酸化。与VEGF和MOR之间的关系一致,我们发现VEGF上调了MOR蛋白和RNA在mREC中的表达。这些数据表明,MOR关联并反式激活了Flk1和PDGF-β 的RTKs,这可能对内皮中的血管生成信号传导具有复合作用。因此,包括MOR在内的g蛋白偶联受体为开发抗血管生成剂提供了新的靶标。
  • 【生长激素-胰岛素样生长因子-I轴中的遗传疾病。】 复制标题 收藏 收藏
    DOI:10.1159/000095161 复制DOI
    作者列表:Walenkamp MJ,Wit JM
    BACKGROUND & AIMS: :In the last few years, our knowledge of genetically determined causes of short stature has greatly increased by reports of challenging patients, who offered the opportunity to study genes that play a role in growth. Since the first paper that showed the etiology of Laron syndrome [Godowski PJ, et al: Proc Natl Acad Sci USA 1989;86:8083-8087], many mutations in the growth hormone (GH) receptor have been identified. Recently, new mutations or deletions have been found in several components of the GH-insulin-like growth factor-I (IGF-I) axis: a homozygous mutation of the GH1 gene, resulting in a bio-inactive GH; mutations in the STAT5b gene, which plays a major role in the GH signal transduction; a homozygous missense mutation in the IGF-I gene; heterozygous mutations in the IGF-I receptor gene and a homozygous deletion of the acid-labile subunit gene. In this mini review, we describe the clinical and biochemical features of these genetic defects. Genetic analysis has become essential in the diagnostic workup of a patient with short stature. However, regarding the time consuming nature of molecular analysis, it is important to carefully select the patient for specific genetic evaluation. To help in this selection process, we developed flowcharts, based on the recently described patients, that can be used as guidelines in the diagnostic process of patients with severe short stature of unknown origin.
    背景与目标: : 在过去的几年中,由于有挑战性的患者的报道,我们对基因确定的矮小原因的了解大大增加了,他们提供了研究在生长中起作用的基因的机会。自从第一篇显示拉隆综合征病因的论文 [Godowski PJ等人: Proc Natl Acad Sci USA 1989;86:8083-8087] 以来,已经鉴定出生长激素 (GH) 受体的许多突变。最近,在GH-胰岛素样生长因子-I (igf-i) 轴的几个组成部分中发现了新的突变或缺失: GH1基因的纯合突变,导致了具有生物活性的GH; STAT5b基因的突变,在GH信号转导中起主要作用; Igf-i基因中的纯合错义突变; Igf-i受体基因中的杂合突变和酸不稳定亚基基因的纯合缺失。在这篇小型综述中,我们描述了这些遗传缺陷的临床和生化特征。基因分析在身材矮小的患者的诊断检查中已变得至关重要。但是,关于分子分析的耗时性质,重要的是要仔细选择患者以进行特定的遗传评估。为了帮助这一选择过程,我们根据最近描述的患者开发了流程图,该流程图可作为不明原因严重矮小患者诊断过程的指南。
  • 【Ro 19-3704通过独立于其血小板活化因子拮抗剂特性的机制直接抑制免疫球蛋白E依赖性介质的释放。】 复制标题 收藏 收藏
    DOI:10.1016/0014-2999(90)90018-2 复制DOI
    作者列表:Gilfillan AM,Wiggan GA,Hope WC,Patel BJ,Welton AF
    BACKGROUND & AIMS: :Rat basophilic leukemia (RBL 2H3) cells were passively sensitized by exposure to monoclonal anti-trinitrophenol mouse immunoglobulin E (anti-trinitrophenol IgE) (0.5 microgram/ml) and triggered by exposure to a sub-optimal concentration of trinitrophenol ovalbumin conjugate (5 ng/ml). At this concentration, trinitrophenol-ovalbumin increased histamine release from a basal rate of 4.8 +/- 0.5 to 28.5 +/- 4.6% and peptidoleukotrienes from less than 0.1 to 4.2 +/- 1.3 ng/10(6) cells in the activated cells. Ro 19-3704 and Ro 19-1400, platelet activating factor (PAF) antagonists which are structural analogs of PAF, potently inhibited both the IgE-dependent release of histamine (IC50 values of 3.0 and 3.6 microM, respectively) and LT release (IC50 values of 5.0 microM for both compounds) from the cells. These effects appeared to be independent to the ability of the compounds to act as PAF antagonists since PAF on its own had no effect on mediator release, and WEB 2086 and BN 52021, structurally distinct PAF antagonists, were relatively ineffective as inhibitors of mediator release. Ro 19-3704 and Ro 19-1400 were observed to be potent inhibitors of the soluble phospholipase A2 activity in synovial fluid from rheumatoid arthritic patients (IC50 values of 6.5 and 8.4 microM, respectively). In contrast, WEB 2086 and BN 52021 had no effect on this phospholipase A2. Ro 19-3704 significantly inhibited the IgE-dependent formation of inositol phosphates in RBL 2H3 cells (IC50 value of 7.0 microM). These data suggest that the mediator release inhibitory action of these compounds may be related to the ability of these compounds to inhibit phospholipase A2 and/or phospholipase C.
    背景与目标: : 大鼠嗜碱性白血病 (rbl2h3) 细胞通过暴露于单克隆抗三硝基酚小鼠免疫球蛋白E (抗三硝基酚IgE) (0.5微克/毫升) 而被动致敏,并通过暴露于次优浓度的三硝基酚卵白蛋白缀合物 (5 ng/毫升) 而触发。在该浓度下,三硝基苯酚-卵清蛋白在活化细胞中增加组胺释放,从4.8 +/- 0.5的基础速率增加到28.5 +/- 4.6%,肽白三烯从小于0.1增加到4.2 +/- 1.3 ng/10(6) 细胞。血小板活化因子 (PAF) 拮抗剂Ro 19-3704和Ro 19-1400是PAF的结构类似物,可有效抑制组胺的IgE依赖性释放 (3.0和3.6 microM的IC50值,分别) 和LT从细胞释放 (两种化合物的5.0微米的IC50值)。这些作用似乎与化合物作为PAF拮抗剂的能力无关,因为PAF本身对介质释放没有影响,并且结构上不同的PAF拮抗剂WEB 2086和BN 52021作为介质释放的抑制剂相对无效。观察到Ro 19-3704和Ro 19-1400是类风湿关节炎患者滑液中可溶性磷脂酶A2活性的有效抑制剂 (IC50值分别为6.5和8.4 microM)。相反,WEB 2086和BN 52021对该磷脂酶a2没有影响。Ro 19-3704显著抑制RBL 2H3细胞中肌醇磷酸盐的IgE依赖性形成 (7.0 microM的IC50值)。这些数据表明,这些化合物的介体释放抑制作用可能与这些化合物抑制磷脂酶A2和/或磷脂酶C的能力有关。
  • 【交联聚 (1-乙烯基-2-吡咯烷酮) 凝胶对静态细胞培养中细胞生长的影响。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Hong Y,Chirila TV,Fitton JH,Ziegelaar BW,Constable IJ
    BACKGROUND & AIMS: Poly(1-vinyl-2-pyrrolidinone) (PVP) and copolymers of 1-vinyl-2-pyrrolidinone are insoluble in water when crosslinked but they can absorb very large amounts of water to become syringe-injectable hydrogels. Such gels have been investigated recently as potential substitutes for the vitreous humour in the eye. In this study, during the cytotoxic evaluation by sulforhodamine B colorimetric assay of variously crosslinked PVP gels, it was found that many of them showed protective/growth promoting effects on 3T3 mouse fibroblasts in static cultures, a phenomenon encountered previously only with aqueous solutions of a limited number of natural or synthetic polymers. Particularly, the gels crosslinked with diethylene glycol dimethacrylate (DEGDMA) induced a significant enhancement of cell proliferation, especially in serum-free cultures. No correlation between this effect and the essential gel properties (chemical composition, viscoelasticity and equilibrium water content) could be established. The study demonstrated that crosslinked PVP hydrogels showed a serum-like growth promoting effect on an anchorage-dependent cell line, which may be due to physical protection, inability of the insoluble gels to penetrate cell membranes, and their ability to mimic the extracellular matrix.

    背景与目标: 聚 (1-乙烯基-2-吡咯烷酮) (PVP) 和1-乙烯基-2-吡咯烷酮的共聚物在交联时不溶于水,但它们可以吸收大量的水,成为可注射器注射的水凝胶。最近已经研究了这种凝胶作为眼睛玻璃体液的潜在替代品。在这项研究中,在通过sulforhodamine B比色法对各种交联的PVP凝胶进行细胞毒性评估期间,发现其中许多凝胶对静态培养中的3T3小鼠成纤维细胞表现出保护/促进生长的作用,这种现象以前仅在水溶液中遇到。有限数量的天然或合成聚合物。特别是,与二甘醇二甲基丙烯酸酯 (DEGDMA) 交联的凝胶可显着增强细胞增殖,尤其是在无血清培养物中。无法建立这种作用与基本凝胶特性 (化学成分,粘弹性和平衡水含量) 之间的相关性。研究表明,交联的PVP水凝胶对锚定依赖性细胞系表现出类似血清的生长促进作用,这可能是由于物理保护,不溶性凝胶无法穿透细胞膜以及它们模仿细胞外基质的能力。

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