Zipper

拉链
  • 文章类型: Journal Article
    Notch通路是一种进化上保守的信号系统,在多个水平上受到复杂的调节,并影响发育的不同方面。为了鉴定参与Notch信号及其调节的新成分,我们进行了蛋白质相互作用筛选,将非肌肉肌球蛋白II拉链(Zip)鉴定为Notch的相互作用伴侣。通过免疫共沉淀研究进一步验证了Notch和Zip之间的物理相互作用。免疫细胞化学分析显示Notch和Zip共定位在相同的细胞质区室中。zip的不同等位基因也显示出与Notch途径组分的强遗传相互作用。Zip的下调导致机翼表型,让人想起Notch功能丧失表型和Notch下游靶标的扰动表达,切和死人。Further,Notch和Zip之间的协同相互作用导致这些Notch靶标的高度异位表达。Zip的过表达增强了激活的Notch诱导的幼虫组织肿瘤表型。Notch-Zip协同作用导致JNK途径的活化,从而导致MMP活化和增殖。一起来看,我们的研究结果表明,Zip可能在Notch信号的调节中起重要作用。
    The Notch pathway is an evolutionarily conserved signaling system that is intricately regulated at multiple levels and it influences different aspects of development. In an effort to identify novel components involved in Notch signaling and its regulation, we carried out protein interaction screens which identified non-muscle myosin II Zipper (Zip) as an interacting partner of Notch. Physical interaction between Notch and Zip was further validated by co-immunoprecipitation studies. Immunocytochemical analyses revealed that Notch and Zip co-localize within same cytoplasmic compartment. Different alleles of zip also showed strong genetic interactions with Notch pathway components. Downregulation of Zip resulted in wing phenotypes that were reminiscent of Notch loss-of-function phenotypes and a perturbed expression of Notch downstream targets, Cut and Deadpan. Further, synergistic interaction between Notch and Zip resulted in highly ectopic expression of these Notch targets. Activated Notch-induced tumorous phenotype of larval tissues was enhanced by over-expression of Zip. Notch-Zip synergy resulted in the activation of JNK pathway that consequently lead to MMP activation and proliferation. Taken together, our results suggest that Zip may play an important role in regulation of Notch signaling.
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  • 文章类型: Journal Article
    淋巴毛细血管形成不连续的细胞-细胞连接,允许吸收大分子,乳糜微粒,和间质的液体。虽然过度的血管内皮生长因子2(VEGFR2)信号可以重塑和密封这些连接,VEGFR3是否以及如何改变淋巴连接仍未完全了解。这里,我们使用淋巴特异性Flt4敲除小鼠来研究淋巴连接中的VEGFR3信号传导。我们表明,Flt4的丢失可防止多种组织中形成专门的纽扣连接,并损害间质吸收。人淋巴管内皮细胞中FLT4的敲除导致NOTCH1表达和活化受损,Flt4敲除血管中NOTCH1细胞内结构域的过表达挽救了按钮连接的形成和间质分子的吸收。一起,我们的数据显示,在出生后发育过程中,纽扣连接的发育需要VEGFR3和NOTCH1信号传导,并且可能与VEGFR3信号传导受损的淋巴疾病具有临床相关性.
    Lymphatic capillaries develop discontinuous cell-cell junctions that permit the absorption of large macromolecules, chylomicrons, and fluid from the interstitium. While excessive vascular endothelial growth factor 2 (VEGFR2) signaling can remodel and seal these junctions, whether and how VEGFR3 can alter lymphatic junctions remains incompletely understood. Here, we use lymphatic-specific Flt4 knockout mice to investigate VEGFR3 signaling in lymphatic junctions. We show that loss of Flt4 prevents specialized button junction formation in multiple tissues and impairs interstitial absorption. Knockdown of FLT4 in human lymphatic endothelial cells results in impaired NOTCH1 expression and activation, and overexpression of the NOTCH1 intracellular domain in Flt4 knockout vessels rescues the formation of button junctions and absorption of interstitial molecules. Together, our data reveal a requirement for VEGFR3 and NOTCH1 signaling in the development of button junctions during postnatal development and may hold clinical relevance to lymphatic diseases with impaired VEGFR3 signaling.
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  • 文章类型: Journal Article
    果蝇的分支形态发生和无缝管形成对于血管和气管系统的发育至关重要,对研究复杂的分支结构如人体器官具有指导意义。拉链是肌球蛋白II的肌动蛋白结合重链;因此,这对收缩肌动蛋白很重要,细胞增殖,和细胞片粘附在D.melanogaster幼虫发育中气管系统的分支。然而,拉链在幼虫中的具体作用仍然存在疑问。本文旨在研究拉链在早期发育阶段的分支形态发生和腔形成中的特定作用。通过检查蛋白质在末端细胞的细胞质中的定位以及通过分析拉链RNAi功能丧失突变体在末端细胞中的分支和管腔形成方面的形态来做到这一点。还进行了RNAi突变体的拯救实验以检查Zipper在分枝形态发生中的充分性。共聚焦成像显示拉链在末端细胞的细胞质中的定位,和各自的定量分析表明,拉链RNAi末端细胞产生的分支明显减少。这样的结果表明,拉链是调节黑腹D的末端细胞中的分支所必需的。然而,拉链不显著参与无缝管的形成。一种假设是,拉链在外侧表皮前缘的收缩性允许细胞片移动和各自的伸长;由于这种伸长,进一步的分支可能发生在细胞的细长区域,因此定义了气管系统末端细胞的分支形态发生。
    Branching morphogenesis and seamless tube formation in Drosophila melanogaster are essential for the development of vascular and tracheal systems, and instructive in studying complex branched structures such as human organs. Zipper is a myosin II\'s actin-binding heavy chain; hence, it is important for contracting actin, cell proliferation, and cell sheet adhesion for branching of the tracheal system in post-larval development of the D. melanogaster. Nevertheless, the specific role of Zipper in the larva is still in question. This paper intended to investigate the specific role of Zipper in branching morphogenesis and lumenogenesis in early developmental stages. It did so by checking the localization of the protein in the cytoplasm of the terminal cells and also by analyzing the morphology of zipper RNAi loss-of-function mutants in regard to branching and lumen formation in the terminal cells. A rescue experiment of RNAi mutants was also performed to check the sufficiency of Zipper in branching morphogenesis. Confocal imaging showed the localization of Zipper in the cytoplasm of the terminal cells, and respective quantitative analyses demonstrated that zipper RNAi terminal cells develop significantly fewer branches. Such a result hinted that Zipper is required for the regulation of branching in the terminal cells of D. melanogaster. Nevertheless, Zipper is not significantly involved in the formation of seamless tubes. One hypothesis is that Zipper\'s contractility at the lateral epidermis\' leading edge allows cell sheet movement and respective elongation; as a result of such an elongation, further branching may occur in the elongated region of the cell, hence defining branching morphogenesis in the terminal cells of the tracheal system.
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  • 文章类型: Journal Article
    缝合线和U形钉是全关节置换术中的主要伤口闭合技术。诸如拉链装置和新型皮肤粘合剂的较新技术已经出现,因为它们有可能减少手术时间并可能使并发症最小化。这项研究的目的是将这些较新的技术与传统的缝合线在伤口并发症方面进行比较。关闭时间,和成本。
    对160名患者进行了单中心随机对照试验(52个拉链,55缝合线,53目),在2017年2月至2018年5月期间接受了初次全髋关节或膝关节置换术。患者分为3个闭合组:拉链装置,单丝缝合线加粘合剂,和单丝加上聚酯网与粘合剂。主要终点是闭合时间(浅皮肤层)。其次,我们收集围手术期并发症发生率,包括感染,持续(14天)伤口引流,90天重新接纳,和急诊室就诊率以及比较的材料成本。
    年龄组间的基线特征没有差异,身体质量指数,和美国麻醉医师学会分类。缝合组有缩短闭合时间的趋势。对于我们的次要终点,组间没有显着差异,并发症。
    我们的研究表明,缝合组的闭合时间更短,但提示全关节置换术后的每种闭合方法的并发症发生率相同。闭合时间差异较小,并发症无明显差异,决定使用一种伤口闭合装置或技术而不是另一种伤口闭合装置或技术应该由机构成本和提供者熟悉程度决定.
    UNASSIGNED: Sutures and staples are the mainstay wound closure techniques in total joint arthroplasty. Newer techniques such as zipper devices and novel skin adhesives have emerged because of their potential to decrease operative time and possibly minimize complications. The aim of this study is to compare these newer techniques against conventional sutures with respect to wound complications, closure time, and costs.
    UNASSIGNED: A single-center randomized control trial was conducted on 160 patients (52 zipper, 55 suture, 53 mesh) who underwent primary total hip or knee arthroplasty between February 2017 and May 2018. Patients were divided into 3 closure groups: zipper device, monofilament suture plus adhesive, and monofilament plus polyester mesh with adhesive. The primary endpoint was closure time (superficial skin layer). Secondarily we collected perioperative complication rates, including infection, persistent (14-day) wound drainage, 90-day readmission, and emergency room visit rates as well as compared material costs.
    UNASSIGNED: There were no differences in baseline characteristics between groups for age, body mass index, and American Society of Anesthesiologists classification. There was a trend toward decreased time to closure for the suture group. There were no significant differences between groups for our secondary endpoint, complications.
    UNASSIGNED: Our study shows that the suture group trended toward shorter closure time but suggests that each of the closure methods after total joint arthroplasty has equivalent complication rates. With small differences in closure time and no significant differences in complications, the decision to use one wound closure device or technique over another should be driven by institutional costs and provider familiarity.
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  • 文章类型: Journal Article
    We performed an updated meta-analysis to compare the efficacy of the zipper device and sutures for wound closure after surgery. A computerised literature search was performed for published trials in PubMed, Web of Science, the Cochrane Library, and Google Scholar. Two reviewers independently scrutinised the trials, extracted data, and assessed the quality of trials. The primary outcome was surgical site infections (SSI). The secondary outcomes were wound dehiscence, total wound complications, wound closure time, and scar score. Statistical analysis was performed in the Stata 12.0. Of the 130 citations, eight trials (1207 participants) met eligibility criteria and were included. The zipper device achieved a lower SSI rate (RR: 0.63, [95% CI: 0.41-0.96, P = 0.032]), a shorter wound closure time (SMD: -8.53 [95% CI: -11.93 to -5.13, P = 0.000]) and a better scar score (SMD: 0.42 [95% CI: 0.22-0.62, P = 0.000]) than sutures. No significant difference was shown in the incidence of wound dehiscence and total wound complications. Therefore, the zipper device provides the advantages of anti-infection, time-saving, and cosmesis for wound closure.
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  • 文章类型: Journal Article
    Rho signaling is a conserved mechanism for generating forces through activation of contractile actomyosin. How this pathway can produce different cell morphologies is poorly understood. In the Drosophila embryonic epithelium, we investigate how Rho signaling controls force asymmetry to drive morphogenesis. We study a distinct morphogenetic process termed \'alignment\'. This process results in striking columns of rectilinear cells connected by aligned cell-cell contacts. We found that this is driven by contractile actomyosin cables that elevate tension along aligning interfaces. Our data show that polarization of Rho effectors, Rok and Dia, directs formation of these cables. Constitutive activation of these effectors causes aligning cells to instead invaginate. This suggests that moderating Rho signaling is essential to producing the aligned geometry. Therefore, we tested for feedback that could fine-tune Rho signaling. We discovered that F-actin exerts negative feedback on multiple nodes in the pathway. Further, we present evidence that suggests that Rok in part mediates feedback from F-actin to Rho in a manner independent of Myo-II. Collectively, our work suggests that multiple feedback mechanisms regulate Rho signaling, which may account for diverse morphological outcomes.
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  • 文章类型: Journal Article
    为了建立感染,沙门氏菌必须与真核细胞相互作用。非吞噬细胞的侵袭(即,上皮,成纤维细胞和内皮细胞)涉及由T3SS-1或侵袭素Rck介导的触发或拉链机制,分别。另一种外膜蛋白,PagN,也与入侵有关。然而,以前曾提出过其他未知的入侵因素。我们的目标是评估鼠伤寒沙门氏菌菌株在三种已知入侵因素下无效的入侵能力。在庆大霉素保护测定中测试了几种动物来源的非吞噬细胞系。在大多数细胞中,我们观察到野生型和三重突变体之间的侵袭率急剧下降。然而,在五种细胞系中,三重突变体以与野生型相似的高水平侵入细胞,提示存在身份不明的入侵因素。对于野生型和三重突变体,扫描电子显微镜,共聚焦成像和生化抑制剂的使用证实了它们的细胞摄取,并显示了拉链样的内化机制,涉及网格蛋白依赖性和非网格蛋白依赖性途径.尽管具有功能性T3SS-1,但野生型细菌似乎与我们的细胞模型中的突变体使用相同的进入途径。一起,这些结果表明存在未知的沙门氏菌入侵因素,这需要进一步表征。
    To establish an infection, Salmonella has to interact with eukaryotic cells. Invasion of non-phagocytic cells (i.e., epithelial, fibroblast and endothelial cells) involves either a trigger or a zipper mechanism mediated by the T3SS-1 or the invasin Rck, respectively. Another outer membrane protein, PagN, was also implicated in the invasion. However, other unknown invasion factors have been previously suggested. Our goal was to evaluate the invasion capability of a Salmonella Typhimurium strain invalidated for the three known invasion factors. Non-phagocytic cell lines of several animal origins were tested in a gentamicin protection assay. In most cells, we observed a drastic decrease in the invasion rate between the wild-type and the triple mutant. However, in five cell lines, the triple mutant invaded cells at a similarly high level to the wild-type, suggesting the existence of unidentified invasion factors. For the wild-type and the triple mutant, scanning-electron microscopy, confocal imaging and use of biochemical inhibitors confirmed their cellular uptake and showed a zipper-like mechanism of internalization involving both clathrin- and non-clathrin-dependent pathways. Despite a functional T3SS-1, the wild-type bacteria seemed to use the same entry route as the mutant in our cell model. All together, these results demonstrate the existence of unknown Salmonella invasion factors, which require further characterization.
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  • 文章类型: Journal Article
    Many of the major discoveries in the fields of genetics and developmental biology have been made using the fruit fly, Drosophila melanogaster. With regard to heart development, the conserved network of core cardiac transcription factors that underlies cardiogenesis has been studied in great detail in the fly, and the importance of several signaling pathways that regulate heart morphogenesis, such as Slit/Robo, was first shown in the fly model. Recent technological advances have led to a large increase in the genomic data available from patients with congenital heart disease (CHD). This has highlighted a number of candidate genes and gene networks that are potentially involved in CHD. To validate genes and genetic interactions among candidate CHD-causing alleles and to better understand heart formation in general are major tasks. The specific limitations of the various cardiac model systems currently employed (mammalian and fish models) provide a niche for the fly model, despite its evolutionary distance to vertebrates and humans. Here, we review recent advances made using the Drosophila embryo that identify factors relevant for heart formation. These underline how this model organism still is invaluable for a better understanding of CHD.
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  • 文章类型: Journal Article
    BACKGROUND: On a daily basis, dermasurgeons are faced with different kinds of wounds that have to be closed. With a plethora of skin closure materials currently available, choosing a solution that combines excellent and rapid cosmetic results with practicality and cost-effectiveness can be difficult, if not tricky.
    OBJECTIVE: We aimed to review the available skin closure materials over the past 20 years and the scientific claims behind their effectiveness in repairing various kinds of wounds.
    METHODS: The two authors independently searched and scrutinised the literature. The search was performed electronically using Pub Med, the Cochrane Database, Google Scholar and Ovid as search engines to find articles concerning skin closure materials written since 1990.
    CONCLUSIONS: Many factors are involved in the choice of skin closure material, including the type and place of the wound, available materials, physician expertise and preferences, and patient age and health. Evidence-based main uses of different skin closure materials are provided to help surgeons choose the appropriate material for different wounds.
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  • 文章类型: Journal Article
    亨廷顿蛋白的17-氨基酸N端片段,htt(NT),在生理条件下孵育时,可以长成稳定的富含α-螺旋的寡聚聚集体。我们检查了htt(NT)肽的15个乱序序列版本在低微摩尔浓度和生理条件下在水溶液中的稳定性。令人惊讶的是,鉴于它们是从容易组装成无法转化为β结构的高度稳定的α-螺旋聚集体的序列衍生而来的,我们发现这些杂乱的肽中的三种迅速生长成淀粉样蛋白样纤维,而另外两个淀粉样蛋白的发育也比较慢。在这些条件下孵育100小时后,其他10种乱序的肽没有可检测地形成任何聚集体。然后我们使用四种先前描述的算法分析这些序列,用于预测肽生长成淀粉样蛋白或其他β-聚集体的趋势。我们发现这些算法-Zyggregator,探戈,华尔兹,和拉链在预测为淀粉样蛋白生成的序列的数量以及正确识别该乱序肽集合的淀粉样蛋白形成成员的能力方面差异很大。在回顾目前认为对确定淀粉样蛋白形成动力学和热力学很重要的序列和结构因素的背景下讨论了结果。
    The 17- amino acid N-terminal segment of the Huntingtin protein, htt(NT), grows into stable α-helix rich oligomeric aggregates when incubated under physiological conditions. We examined 15 scrambled sequence versions of an htt(NT) peptide for their stabilities against aggregation in aqueous solution at low micromolar concentration and physiological conditions. Surprisingly, given their derivation from a sequence that readily assembles into highly stable α-helical aggregates that fail to convert into β-structure, we found that three of these scrambled peptides rapidly grow into amyloid-like fibrils, while two others also develop amyloid somewhat more slowly. The other 10 scrambled peptides do not detectibly form any aggregates after 100 h incubation under these conditions. We then analyzed these sequences using four previously described algorithms for predicting the tendencies of peptides to grow into amyloid or other β-aggregates. We found that these algorithms-Zyggregator, Tango, Waltz, and Zipper-varied greatly in the number of sequences predicted to be amyloidogenic and in their abilities to correctly identify the amyloid forming members of this scrambled peptide collection. The results are discussed in the context of a review of the sequence and structural factors currently thought to be important in determining amyloid formation kinetics and thermodynamics.
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