Integrins

整合素
  • 文章类型: Case Reports
    背景:接受免疫抑制剂的自身免疫性疾病患者有发生非霍奇金淋巴瘤(NHL)的风险。维多珠单抗(抗α4β7整合素抗体),克罗恩病(CD)的首选治疗方法,减少炎性淋巴细胞运输到肠粘膜。这种作用被认为局限于结肠。
    方法:我们报告了一例使用维多珠单抗治疗5年的CD患者,其发展为小儿型滤泡性淋巴瘤。治疗前的检查显示,循环T淋巴细胞减少,对有丝分裂原的反应受到抑制。利妥昔单抗,环磷酰胺,长春新碱,和泼尼松化学免疫疗法导致持久的淋巴瘤缓解,维多珠单抗继续治疗.而患者的T淋巴细胞群和免疫球蛋白产生恢复,T淋巴细胞有丝分裂原反应仍然受到抑制。
    结论:该患者的NHL可能与接受抗α4β7治疗有关。进一步的研究可能有助于确定是否在接受维多珠单抗治疗的患者中对NHL和其他全身性疾病进行主动监测。
    BACKGROUND: Patients with autoimmune conditions receiving immunosuppressants are at risk of non-Hodgkin lymphomas (NHL). Vedolizumab (anti-α4β7-integrin antibody), a treatment-of-choice for Crohn\'s disease (CD), reduces inflammatory lymphocyte trafficking into the intestinal mucosa. This effect is believed to be confined to the colon.
    METHODS: We report the case of a CD patient on vedolizumab for five years who developed pediatric-type follicular lymphoma. Work-up prior to therapy revealed a reduction in circulating T-lymphocytes and their suppressed response to mitogens. Rituximab, cyclophosphamide, vincristine, and prednisone chemo-immunotherapy resulted in durable lymphoma remission, and vedolizumab treatment was continued. While the patient\'s T-lymphocyte population and immunoglobulin production recovered, the T-lymphocyte mitogen response remained suppressed.
    CONCLUSIONS: This patient\'s NHL may be linked to receiving anti-α4β7 therapy. Further research could be beneficial to determine if proactive surveillance for NHL and other systemic diseases is indicated in patients on vedolizumab.
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  • 文章类型: Journal Article
    机械力对于调节许多生物过程(如细胞分化)至关重要。扩散,和死亡。通过整合素受体探测不断变化的分子力可以深入了解细胞刚性感知的分子机制;然而,部队信息仍然有限。这里,我们建造了一个线圈形的DNA折纸(DNA纳米弹簧,NS)作为力传感器,可报告单个整合素的动态运动以及通过活细胞中整合素的力的大小和方向。我们通过荧光斑点的形状以纳米精度监测了与单个整联蛋白连接的NS的延伸和取向。我们使用声力谱来估计NS的力-延伸曲线,并在从亚皮牛顿(pN)到50pN的广泛可检测范围内确定力的〜10%力误差。我们发现与NS连接的单个整合素移动了几十纳米,收缩和松弛速度在小于约20pN时与负载相关,但在约20pN以上时稳健。随着载荷的增加,牵引力方向的波动得到抑制。我们的测定系统是在分子水平上研究机械传感的潜在强大工具。
    Mechanical forces are critical for regulating many biological processes such as cell differentiation, proliferation, and death. Probing the continuously changing molecular force through integrin receptors provides insights into the molecular mechanism of rigidity sensing in cells; however, the force information is still limited. Here, we built a coil-shaped DNA origami (DNA nanospring, NS) as a force sensor that reports the dynamic motion of single integrins as well as the magnitude and orientation of the force through integrins in living cells. We monitored the extension with nanometer accuracy and the orientation of the NS linked with a single integrin by the shape of the fluorescence spots. We used acoustic force spectroscopy to estimate the force-extension curve of the NS and determined the force with an ∼10% force error at a broad detectable range from subpicoNewtons (pN) to ∼50 pN. We found single integrins tethered with the NS moved several tens of nanometers, and the contraction and relaxation speeds were load dependent at less than ∼20 pN but robust over ∼20 pN. Fluctuations of the traction force orientation were suppressed with increasing load. Our assay system is a potentially powerful tool for studying mechanosensing at the molecular level.
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  • 文章类型: Case Reports
    胶质母细胞瘤(GBM)是最常见的恶性脑肿瘤。不到1%的患者存活时间超过10年。2009年,一名77岁的妇女被诊断出患有MGMT甲基化的GBM。作为CENTRIC临床试验的一部分,患者接受了西伦吉肽与标准放疗和化疗。尽管该研究在2013年停止,但我们的患者直到2016年才接受西伦吉肽治疗,到目前为止没有影像学证据表明复发。这是报告的年龄最大的GBM患者,生存期超过10年。她的异常反应可能受到MGMT启动子甲基化状态和PTEN表达的影响。
    Glioblastoma (GBM) is the most common malignant brain tumor. Less than 1% of patients survive longer than 10 years. A 77-year-old woman was diagnosed with MGMT-methylated GBM in 2009. The patient received cilengitide as part of the CENTRIC clinical trial in conjunction with standard radiation and chemotherapy. Though the study was halted in 2013, our patient received cilengitide until 2016 with no radiographic evidence of recurrence thus far. This is the oldest reported GBM patient with greater than 10-year survival. Her exceptional response may have been influenced by MGMT promoter methylation status and PTEN expression.
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  • 文章类型: Journal Article
    整合素受体是既定的药物靶标,但是许多已经开发的药物作为部分激动剂,诱导受体进入高亲和力,配体结合状态。Linetal.发现了一种避免这个问题的一般机制-稳定阻止受体激活的关键水分子。他们的发现可能会影响未来的治疗发展。
    Integrin receptors are established drug targets, but many of the drugs that have been developed act as partial agonists, inducing the receptor into a high-affinity, ligand-binding state. Lin et al. discovered a general mechanism to circumvent this problem-stabilizing a key water molecule that prevents receptor activation. Their findings are likely to impact future therapeutic development.
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  • 文章类型: Journal Article
    二十多年前作为一种学术好奇心开始,离子通道可以以不依赖于其传导特性(非离子功能)的方式调节细胞过程的想法获得了牵引力,现在是一个蓬勃发展的研究领域。通道可以调节生理过程,包括肌动蛋白细胞骨架重塑,细胞运动性,激励-收缩耦合,非联想学习和胚胎发生,只是提到一些,通过非离子函数。有缺陷时,非离子功能可以引起与癌症有关的通道病,神经退行性疾病和脑外伤。离子通道通过各种机制发挥其非离子功能,这些机制包括与其他蛋白质的物理耦合,具有酶活性,与信号分子组装。在这篇文章中,我们评估了该领域并回顾了最近的发现。出现的概念,是渠道获得非离子属性的最常见方式之一,是通过与整合素组装。这些整合素-通道复合物表现出广泛的基因型和表型异质性,并显示多效性。因为它们似乎能够影响生理和病理过程。
    Started as an academic curiosity more than two decades ago, the idea that ion channels can regulate cellular processes in ways that do not depend on their conducting properties (non-ionic functions) gained traction and is now a flourishing area of research. Channels can regulate physiological processes including actin cytoskeletal remodeling, cell motility, excitation-contraction coupling, non-associative learning and embryogenesis, just to mention some, through non-ionic functions. When defective, non-ionic functions can give rise to channelopathies involved in cancer, neurodegenerative disease and brain trauma. Ion channels exert their non-ionic functions through a variety of mechanisms that range from physical coupling with other proteins, to possessing enzymatic activity, to assembling with signaling molecules. In this article, we take stock of the field and review recent findings. The concept that emerges, is that one of the most common ways through which channels acquire non-ionic attributes, is by assembling with integrins. These integrin-channel complexes exhibit broad genotypic and phenotypic heterogeneity and reveal a pleiotropic nature, as they appear to be capable of influencing both physiological and pathological processes.
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  • 文章类型: Journal Article
    细胞功能受扩散和局部信号的复杂相互作用调节。研究后者是具有挑战性的,但是细胞生理学的实验工作已经使人们认识到,理解细胞的动力学需要对细胞溶质调节因子的局部波动有深刻的理解。大分子复合物是局部信号传导的主要决定因素。多酶组装体通过代谢物的直接交换将扩散限制限制为反应动力学。同样,离子通道和转运蛋白的紧密耦合调节通道口或转运蛋白结合位点周围的离子浓度。极端信号局部性是由膜蛋白之间的构象偶联引起的,这是典型的机械传导。典型的情况是整合素介导的细胞粘附。感知细胞外微环境并提供适当的反应在生长和发育中至关重要,并且具有无数的病理意义。该过程涉及通过将整联蛋白受体与离子通道和转运体连接的复杂超分子结构进行双向信号转导。生长因子受体,细胞骨架元素,和其他监管要素。这种复合物的动力学才刚刚开始被理解。一个经过深入研究的例子是整合素受体与电压门控K通道Kv11.1之间的关联。这些通道在早期胚胎中广泛表达,对它们的生理作用知之甚少,显然与成年人动作电位放电的形成不同。关于这些作用的提示来自癌细胞的研究,其中Kv11.1通常是过表达的,并且似乎重新假定了它在胚胎发生过程中可能发挥的功能,如控制细胞增殖/分化,凋亡,和移民。Kv11.1通过与整联蛋白亚基的连接参与了这些过程,进而调节通道表达。特定的细胞功能,如扩散和迁移,似乎是由通道的不同构象状态调制的(例如,打开和关闭),其平衡受到与整合素亚基的联系的影响。
    The cellular functions are regulated by a complex interplay of diffuse and local signals. Studying the latter is challenging, but experimental work in cell physiology has led to recognize that understanding a cell\'s dynamics requires a deep comprehension of local fluctuations of cytosolic regulators. Macromolecular complexes are major determinants of local signaling. Multienzyme assemblies limit the diffusion restriction to reaction kinetics by direct exchange of metabolites. Likewise, close coupling of ion channels and transporters modulates the ion concentration around a channel mouth or transporter binding site. Extreme signal locality is brought about by conformational coupling between membrane proteins, as is typical of mechanotransduction. A paradigmatic case is integrin-mediated cell adhesion. Sensing the extracellular microenvironment and providing an appropriate response are essential in growth and development and have innumerable pathological implications. The process involves bidirectional signal transduction by complex supramolecular structures that link integrin receptors to ion channels and transporters, growth factor receptors, cytoskeletal elements, and other regulatory elements. The dynamics of such complexes are only beginning to be understood. A thoroughly studied example is the association between integrin receptors and the voltage-gated K+ channels Kv11.1. These channels are widely expressed in early embryos, where their physiological roles are poorly understood and apparently different from the shaping of action potential firing in the adult. Hints about these roles come from studies in cancer cells, where Kv11.1 is often overexpressed and appears to reassume functions it presumably exerts during embryogenesis, such as controlling cell proliferation/differentiation, apoptosis, and migration. Kv11.1 is implicated in these processes through its linking to integrin subunits, which in turn regulates channel expression. Specific cellular functions, such as proliferation and migration, appear to be modulated by distinct conformational states of the channel (e.g., open and closed), whose balance is affected by the link with integrin subunits.
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  • 文章类型: Journal Article
    General population is exposed to dibutyl phthalate (DBP) through continuous use of various consumer products. DBP exhibits its effects mainly on the endocrine and reproductive system but it can also affect the function of the vasculature; however, the underlying mechanisms behind DBP-induced vascular dysfunction are not fully understood. To infer pathways, molecular functions, biological processes, and human diseases associated with DBP exposure, we integrated the toxicogenomic data obtained from the 4-week-long exposure of human vascular endothelial cells (ECs) to three environmentally relevant concentrations of DBP with the in silico analysis. Nine genes were affected by DBP exposure: six of the integrin family, VCAM1, ICAM1, and MMP2. As shown by the in silico analysis, changes in DBP-affected genes could affect extracellular matrix and binding of molecules and cells to ECs, thereby altering cell adhesion and migration. Several pathways, molecular functions, and biological processes were further identified to provide insight into the DBP-vascular disease relationships and the potential mechanism of action. The top three human disease categories associated with DBP exposure and vascular dysfunction include cardiovascular, cerebrovascular, and immune system diseases. Integration of experimental and in silico approaches may offer better understanding of the potential human health risks associated with DBP exposure.
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  • 癌症是全球范围内的主要健康问题,是仅次于心血管疾病的第二大死亡原因。乳腺癌是女性死亡和发病的主要原因,也是导致转移性疾病的最常见恶性肿瘤之一。在本次审查中,讨论了参与肿瘤侵袭的主要细胞粘附分子的机制,关注乳腺癌的情况。对文献进行了非系统的更新修订,以收集有关与转移相关的粘附细胞分子表达的信息。
    Cancer is a major health problem worldwide and the second leading cause of death following cardiovascular diseases. Breast cancer is the leading cause of mortality and morbidity among women and one of the most common malignant neoplasms prompt to metastatic disease. In the present review, the mechanisms of the major cell adhesion molecules involved in tumor invasion are discussed, focusing on the case of breast cancer. A non-systematic updated revision of the literature was performed in order to assemble information regarding the expression of the adhesion cell molecules associated with metastasis.
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  • 文章类型: Journal Article
    BACKGROUND: α4β7 is a gut-homing integrin heterodimer that can act as a non-essential binding molecule for HIV. A previous study in heterosexual African women found that individuals with higher proportions of α4β7 expressing CD4+ T cells were more likely to become infected with HIV, as well as present with faster disease progression. It is unknown if this phenomenon is also observed in men who have sex with men (MSM) or people who inject drugs (PWID).
    METHODS: MSM and transgender women who seroconverted as part of the HVTN 505 HIV vaccine trial and PWID who seroconverted during the ALIVE cohort study were selected as cases and matched to HIV-uninfected controls from the same studies (1:1 and 1:3, respectively). Pre-seroconversion PBMC samples from cases and controls in both studies were examined by flow cytometry to measure levels of α4β7 expression on CD4+ T cells. Multivariable conditional logistic regression was used to compare α4β7 expression levels between cases and controls. A Kaplan-Meier curve was used to examine the association of α4β7 expression pre-seroconversion with HIV disease progression.
    RESULTS: In MSM and transgender women (n = 103 cases, 103 controls), there was no statistically significant difference in the levels of α4β7 expression on CD4+ T cells between cases and controls (adjusted odds ratio [adjOR] =1.10, 95% confidence interval [CI]=0.94,1.29; p = 0.246). Interestingly, in PWID (n = 49 cases, 143 controls), cases had significantly lower levels of α4β7 expression compared to their matched controls (adjOR = 0.80, 95% CI = 0.68, 0.93; p = 0.004). Among HIV-positive PWID (n = 47), there was no significant association in HIV disease progression in individuals above or below the median level of α4β7 expression (log-rank p = 0.84).
    CONCLUSIONS: In contrast to findings in heterosexual women, higher α4β7 expression does not predict HIV acquisition or disease progression in PWID or MSM.
    BACKGROUND: This study was supported in part by the Division of Intramural Research, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health. The study was also supported by extramural grants from NIAID T32AI102623 (E.U.P.), and UM1AI069470.
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  • 文章类型: Journal Article
    Cancer is a disease characterized by its high morbidity and mortality, mainly due to its metastatic ability. Metastasis is a multi-step process beginning with detachment of tumor cells from the primary tumor and leading ultimately to the establishment of a new tumoral site. This cascade includes intravascular migration of tumor cells either individually or collectively and the expansion of cancer cells at metastatic sites that is dependent on certain conditions such as an immunosuppressive environment. In this paper, blockers of tumor cell migration and suppressors of immunotolerance at metastatic sites are reviewed as an illustration of early and later phases intervention, respectively. A combination of these two therapeutics will be advocated based on the proposition of correlation between the pattern of tumor cell migration and the mechanism of immunotolerance induction. By extension, the \'\'delayed complementarity\'\' will be introduced as an approach to formulate new anticancer drug combinations.
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