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Open accessJournal ArticleDOI: 10.3389/FCELL.2021.639952

SARAF and Orai1 Contribute to Endothelial Cell Activation and Angiogenesis

04 Mar 2021-Frontiers in Cell and Developmental Biology (Frontiers Media SA)-Vol. 9, pp 639952-639952
Abstract: Angiogenesis is a multistep process that controls endothelial cells (ECs) functioning to form new blood vessels from preexisting vascular beds. This process is tightly regulated by pro-angiogenic factors, such as vascular endothelial growth factor (VEGF), which promote signaling pathways involving the increase in the intracellular Ca2+ concentration ([Ca2+]i). Recent evidence suggests that store-operated calcium entry (SOCE) might play a role in angiogenesis. However, little is known regarding the role of SARAF, SOCE-associated regulatory factor, and Orai1, the pore-forming subunit of the store-operated calcium channel (SOCC), in angiogenesis. Here, we show that SOCE inhibition with GSK-7975A blocks aorta sprouting, as well as human umbilical vein endothelial cell (HUVEC) tube formation and migration. The intraperitoneal injection of GSK-7975A also delays the development of retinal vasculature assessed at postnatal day 6 in mice, since it reduces vessel length and the number of junctions, while it increases lacunarity. Moreover, we find that SARAF and Orai1 are involved in VEGF-mediated [Ca2+]i increase, and their knockdown using siRNA impairs HUVEC tube formation, proliferation, and migration. Finally, immunostaining and in situ proximity ligation assays indicate that SARAF likely interacts with Orai1 in HUVECs. Therefore, these findings show for the first time a functional interaction between SARAF and Orai1 in ECs and highlight their essential role in different steps of the angiogenesis process.

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6 results found

Open accessJournal ArticleDOI: 10.3390/IJMS22189821
Sharon Negri1, Pawan Faris1, Francesco Moccia1Institutions (1)
Abstract: An increase in intracellular Ca2+ concentration ([Ca2+]i) controls virtually all endothelial cell functions and is, therefore, crucial to maintain cardiovascular homeostasis. An aberrant elevation in endothelial can indeed lead to severe cardiovascular disorders. Likewise, moderate amounts of reactive oxygen species (ROS) induce intracellular Ca2+ signals to regulate vascular functions, while excessive ROS production may exploit dysregulated Ca2+ dynamics to induce endothelial injury. Herein, we survey how ROS induce endothelial Ca2+ signals to regulate vascular functions and, vice versa, how aberrant ROS generation may exploit the Ca2+ handling machinery to promote endothelial dysfunction. ROS elicit endothelial Ca2+ signals by regulating inositol-1,4,5-trisphosphate receptors, sarco-endoplasmic reticulum Ca2+-ATPase 2B, two-pore channels, store-operated Ca2+ entry (SOCE), and multiple isoforms of transient receptor potential (TRP) channels. ROS-induced endothelial Ca2+ signals regulate endothelial permeability, angiogenesis, and generation of vasorelaxing mediators and can be exploited to induce therapeutic angiogenesis, rescue neurovascular coupling, and induce cancer regression. However, an increase in endothelial [Ca2+]i induced by aberrant ROS formation may result in endothelial dysfunction, inflammatory diseases, metabolic disorders, and pulmonary artery hypertension. This information could pave the way to design alternative treatments to interfere with the life-threatening interconnection between endothelial ROS and Ca2+ signaling under multiple pathological conditions.

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2 Citations

Open accessJournal ArticleDOI: 10.3390/CANCERS13143428
Elodie Terrié1, Nadine Déliot1, Yassine Benzidane1, Thomas Harnois1  +10 moreInstitutions (3)
08 Jul 2021-Cancers
Abstract: Glioblastoma is the most frequent and deadly form of primary brain tumors. Despite multimodal treatment, more than 90% of patients experience tumor recurrence. Glioblastoma contains a small population of cells, called glioblastoma stem cells (GSC) that are highly resistant to treatment and endowed with the ability to regenerate the tumor, which accounts for tumor recurrence. Transcriptomic studies disclosed an enrichment of calcium (Ca2+) signaling transcripts in GSC. In non-excitable cells, store-operated channels (SOC) represent a major route of Ca2+ influx. As SOC regulate the self-renewal of adult neural stem cells that are possible cells of origin of GSC, we analyzed the roles of SOC in cultures of GSC previously derived from five different glioblastoma surgical specimens. Immunoblotting and immunocytochemistry experiments showed that GSC express Orai1 and TRPC1, two core SOC proteins, along with their activator STIM1. Ca2+ imaging demonstrated that SOC support Ca2+ entries in GSC. Pharmacological inhibition of SOC-dependent Ca2+ entries decreased proliferation, impaired self-renewal, and reduced expression of the stem cell marker SOX2 in GSC. Our data showing the ability of SOC inhibitors to impede GSC self-renewal paves the way for a strategy to target the cells considered responsible for conveying resistance to treatment and tumor relapse.

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Topics: Cancer stem cell (56%), Stem cell (55%), Stem cell marker (55%) ... show more

1 Citations

Open accessJournal ArticleDOI: 10.3390/CELLS10081887
Inbal Dagan1, Raz Palty1Institutions (1)
26 Jul 2021-Cells
Abstract: Calcium (Ca2+) signaling plays a dichotomous role in cellular biology, controlling cell survival and proliferation on the one hand and cellular toxicity and cell death on the other. Store-operated Ca2+ entry (SOCE) by CRAC channels represents a major pathway for Ca2+ entry in non-excitable cells. The CRAC channel has two key components, the endoplasmic reticulum Ca2+ sensor stromal interaction molecule (STIM) and the plasma-membrane Ca2+ channel Orai. Physical coupling between STIM and Orai opens the CRAC channel and the resulting Ca2+ flux is regulated by a negative feedback mechanism of slow Ca2+ dependent inactivation (SCDI). The identification of the SOCE-associated regulatory factor (SARAF) and investigations of its role in SCDI have led to new functional and molecular insights into how SOCE is controlled. In this review, we provide an overview of the functional and molecular mechanisms underlying SCDI and discuss how the interaction between SARAF, STIM1, and Orai1 shapes Ca2+ signaling in cells.

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Topics: ORAI1 (58%), STIM1 (52%)

1 Citations

Open accessJournal ArticleDOI: 10.3390/CANCERS13164160
19 Aug 2021-Cancers
Abstract: Breast cancer is among the most common malignancies in women. From the molecular point of view, breast cancer can be grouped into different categories, including the luminal (estrogen receptor positive (ER+)) and triple negative subtypes, which show distinctive features and, thus, are sensitive to different therapies. Breast cancer cells are strongly dependent on Ca2+ influx. Store-operated Ca2+ entry (SOCE) has been found to support a variety of cancer hallmarks including cell viability, proliferation, migration, and metastasis. The Ca2+ channels of the Orai family and the endoplasmic reticulum Ca2+ sensor STIM1 are the essential components of SOCE, but the extent of Ca2+ influx is fine-tuned by several regulatory proteins, such as the STIM1 modulators SARAF and EFHB. Here, we show that the expression and/or function of SARAF and EFHB is altered in breast cancer cells and both proteins are required for cell proliferation, migration, and viability. EFHB expression is upregulated in luminal and triple negative breast cancer (TNBC) cells and is essential for full SOCE in these cells. SARAF expression was found to be similar in breast cancer and pre-neoplastic breast epithelial cells, and SARAF knockdown was found to result in enhanced SOCE in pre-neoplastic and TNBC cells. Interestingly, silencing SARAF expression in ER+ MCF7 cells led to attenuation of SOCE, thus suggesting a distinctive role for SARAF in this cell type. Finally, we used a combination of approaches to show that molecular knockdown of SARAF and EFHB significantly attenuates the ability of breast cancer cells to proliferate and migrate, as well as cell viability. In aggregate, SARAF and EFHB are required for the fine modulation of SOCE in breast cancer cells and play an important role in the maintenance of proliferation, migration, and viability in these cells.

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Topics: Triple-negative breast cancer (54%), Estrogen receptor (53%), Cancer (53%) ... show more

Open accessJournal ArticleDOI: 10.3389/FCVM.2021.724846
Bowen Li1, Kun Chen1, Fangfang Liu1, Juan Zhang2  +7 moreInstitutions (2)
Abstract: Background: Mitochondrial aminoacyl-tRNA synthetases (mtARSs) catalyze the binding of specific amino acids to their cognate tRNAs and play an essential role in the synthesis of proteins encoded by mitochondrial DNA. Defects in mtARSs have been linked to human diseases, but their tissue-specific pathophysiology remains elusive. Here we examined the role of mitochondrial phenylalanyl-tRNA synthetase (FARS2) in developmental angiogenesis and its potential contribution to the pathogenesis of cardiovascular disease. Methods: Morpholinos were injected into fertilized zebrafish ova to establish an in vivo fars2 knock-down model. A visualization of the vasculature was achieved by using Tg (fli1: EGFP) y1 transgenic zebrafish. In addition, small interference RNAs (siRNAs) were transferred into human umbilical vein endothelial cells (HUVECs) to establish an in vitro FARS2 knock-down model. Cell motility, proliferation, and tubulogenesis were determined using scratch-wound CCK8, transwell-based migration, and tube formation assays. In addition, mitochondria- and non-mitochondria-related respiration were evaluated using a Seahorse XF24 analyzer and flow cytometry assays. Analyses of the expression levels of transcripts and proteins were performed using qRT-PCR and western blotting, respectively. Results: The knock-down of fars2 hampered the embryonic development in zebrafish and delayed the formation of the vasculature in Tg (fli1: EGFP) y1 transgenic zebrafish. In addition, the siRNA-mediated knock-down of FARS2 impaired angiogenesis in HUVECs as indicated by decreased cell motility and tube formation capacity. The knock-down of FARS2 also produced variable decreases in mitochondrial- and non-mitochondrial respiration in HUVECs and disrupted the regulatory pathways of angiogenesis in both HUVECs and zebrafish. Conclusion: Our current work offers novel insights into angiogenesis defects and cardiovascular diseases induced by FARS2 deficiency.

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Topics: Zebrafish (57%), Tube formation (55%), Angiogenesis (54%) ... show more


40 results found

Journal ArticleDOI: 10.1056/NEJM197111182852108
Abstract: THE growth of solid neoplasms is always accompanied by neovascularization. This new capillary growth is even more vigorous and continuous than a similar outgrowth of capillary sprouts observed in f...

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Topics: Neovascularization (66%), Angiogenesis inhibitor (52%), Tumstatin (52%)

9,319 Citations

Journal ArticleDOI: 10.1111/J.1365-2818.2006.01706.X
Abstract: Summary It is generally accepted that the functional compartmentalization of eukaryotic cells is reflected by the differential occurrence of proteins in their compartments. The location and physiological function of a protein are closely related; local information of a protein is thus crucial to understanding its role in biological processes. The visualization of proteins residing on intracellular structures by fluorescence microscopy has become a routine approach in cell biology and is increasingly used to assess their colocalization with well-characterized markers. However, imageanalysis methods for colocalization studies are a field of contention and enigma. We have therefore undertaken to review the most currently used colocalization analysis methods, introducing the basic optical concepts important for image acquisition and subsequent analysis. We provide a summary of practical tips for image acquisition and treatment that should precede proper colocalization analysis. Furthermore, we discuss the application and feasibility of colocalization tools for various biological colocalization situations and discuss their respective strengths and weaknesses. We have created a novel toolbox for subcellular colocalization analysis under Image J, named JACoP, that integrates current global statistic methods and a novel object-based approach.

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Topics: Colocalization (61%)

3,497 Citations

Book ChapterDOI: 10.1385/1-59259-860-9:023
Abstract: The wound-healing assay is simple, inexpensive, and one of the earliest developed methods to study directional cell migration in vitro. This method mimics cell migration during wound healing in vivo. The basic steps involve creating a "wound" in a cell monolayer, capturing the images at the beginning and at regular intervals during cell migration to close the wound, and comparing the images to quantify the migration rate of the cells. It is particularly suitable for studies on the effects of cell-matrix and cell-cell interactions on cell migration. A variation of this method that tracks the migration of individual cells in the leading edge of the wound is also described in this chapter.

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Topics: Cell migration (55%), Wound healing (50%)

509 Citations

Open accessJournal ArticleDOI: 10.1371/JOURNAL.PONE.0027385
16 Nov 2011-PLOS ONE
Abstract: Angiogenesis is the generation of mature vascular networks from pre-existing vessels. Angiogenesis is crucial during the organism' development, for wound healing and for the female reproductive cycle. Several murine experimental systems are well suited for studying developmental and pathological angiogenesis. They include the embryonic hindbrain, the post-natal retina and allantois explants. In these systems vascular networks are visualised by appropriate staining procedures followed by microscopical analysis. Nevertheless, quantitative assessment of angiogenesis is hampered by the lack of readily available, standardized metrics and software analysis tools. Non-automated protocols are being used widely and they are, in general, time - and labour intensive, prone to human error and do not permit computation of complex spatial metrics. We have developed a light-weight, user friendly software, AngioTool, which allows for quick, hands-off and reproducible quantification of vascular networks in microscopic images. AngioTool computes several morphological and spatial parameters including the area covered by a vascular network, the number of vessels, vessel length, vascular density and lacunarity. In addition, AngioTool calculates the so-called “branching index” (branch points / unit area), providing a measurement of the sprouting activity of a specimen of interest. We have validated AngioTool using images of embryonic murine hindbrains, post-natal retinas and allantois explants. AngioTool is open source and can be downloaded free of charge.

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463 Citations

Journal ArticleDOI: 10.1038/NPROT.2011.435
01 Jan 2012-Nature Protocols
Abstract: Here we provide a protocol for quantitative three-dimensional ex vivo mouse aortic ring angiogenesis assays, in which developing microvessels undergo many key features of angiogenesis over a timescale similar to that observed in vivo. The aortic ring assay allows analysis of cellular proliferation, migration, tube formation, microvessel branching, perivascular recruitment and remodeling-all without the need for cellular dissociation-thus providing a more complete picture of angiogenic processes compared with traditional cell-based assays. Our protocol can be applied to aortic rings from embryonic stage E18 through to adulthood and can incorporate genetic manipulation, treatment with growth factors, drugs or siRNA. This robust assay allows assessment of the salient steps in angiogenesis and quantification of the developing microvessels, and it can be used to identify new modulators of angiogenesis. The assay takes 6-14 d to complete, depending on the age of the mice, treatments applied and whether immunostaining is performed.

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Topics: Angiogenesis (56%), Tube formation (53%), Neovascularization (53%) ... show more

388 Citations