scholarly journals Rac1 and Aurora A regulate MCAK to polarize microtubule growth in migrating endothelial cells

2014 ◽  
Vol 206 (1) ◽  
pp. 97-112 ◽  
Author(s):  
Alexander Braun ◽  
Kyvan Dang ◽  
Felinah Buslig ◽  
Michelle A. Baird ◽  
Michael W. Davidson ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Dynamics ◽  
Aurora A Kinase ◽  
Aurora A ◽  
Directional Migration ◽  
Directional Movement ◽  
Associated Proteins ◽  
Guanosine Triphosphatase ◽  
And Migration ◽  
Computational Image Analysis

Endothelial cells (ECs) migrate directionally during angiogenesis and wound healing by polarizing to extracellular cues to guide directional movement. EC polarization is controlled by microtubule (MT) growth dynamics, which are regulated by MT-associated proteins (MAPs) that alter MT stability. Mitotic centromere-associated kinesin (MCAK) is a MAP that promotes MT disassembly within the mitotic spindle, yet its function in regulating MT dynamics to promote EC polarity and migration has not been investigated. We used high-resolution fluorescence microscopy coupled with computational image analysis to elucidate the role of MCAK in regulating MT growth dynamics, morphology, and directional migration of ECs. Our results show that MCAK-mediated depolymerization of MTs is specifically targeted to the trailing edge of polarized wound-edge ECs. Regulation of MCAK function is dependent on Aurora A kinase, which is regionally enhanced by signaling from the small guanosine triphosphatase, Rac1. Thus, a Rac1–Aurora A–MCAK signaling pathway mediates EC polarization and directional migration by promoting regional differences in MT dynamics in the leading and trailing cell edges.

scholarly journals Clathrin promotes centrosome integrity in early mitosis through stabilization of centrosomal ch-TOG

2012 ◽  
Vol 198 (4) ◽  
pp. 591-605 ◽  
Author(s):  
Amy B. Foraker ◽  
Stéphane M. Camus ◽  
Timothy M. Evans ◽  
Sophia R. Majeed ◽  
Chih-Ying Chen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Kinase Inhibitor ◽  
Coiled Coil ◽  
S Phase ◽  
Aurora A Kinase ◽  
Aurora A ◽  
Multipolar Spindles ◽  
Associated Proteins ◽  
A Cell ◽  
Spindle Stability

Clathrin depletion by ribonucleic acid interference (RNAi) impairs mitotic spindle stability and cytokinesis. Depletion of several clathrin-associated proteins affects centrosome integrity, suggesting a further cell cycle function for clathrin. In this paper, we report that RNAi depletion of CHC17 (clathrin heavy chain 17) clathrin, but not the CHC22 clathrin isoform, induced centrosome amplification and multipolar spindles. To stage clathrin function within the cell cycle, a cell line expressing SNAP-tagged clathrin light chains was generated. Acute clathrin inactivation by chemical dimerization of the SNAP-tag during S phase caused reduction of both clathrin and ch-TOG (colonic, hepatic tumor overexpressed gene) at metaphase centrosomes, which became fragmented. This was phenocopied by treatment with Aurora A kinase inhibitor, suggesting a centrosomal role for the Aurora A–dependent complex of clathrin, ch-TOG, and TACC3 (transforming acidic coiled-coil protein 3). Clathrin inactivation in S phase also reduced total cellular levels of ch-TOG by metaphase. Live-cell imaging showed dynamic clathrin recruitment during centrosome maturation. Therefore, we propose that clathrin promotes centrosome maturation by stabilizing the microtubule-binding protein ch-TOG, defining a novel role for the clathrin–ch-TOG–TACC3 complex.

Centrosome Aurora A gradient ensures single polarity axis in C. elegans embryos

2020 ◽  
Vol 48 (3) ◽  
pp. 1243-1253 ◽  
Author(s):  
Sukriti Kapoor ◽  
Sachin Kotak
Keyword(s):  
Symmetry Breaking ◽  
Cell Fate ◽  
Cell Cortex ◽  
Axis Formation ◽  
Aurora A Kinase ◽  
Aurora A ◽  
C Elegans ◽  
Cell Embryo ◽  
Polarity Establishment

Cellular asymmetries are vital for generating cell fate diversity during development and in stem cells. In the newly fertilized Caenorhabditis elegans embryo, centrosomes are responsible for polarity establishment, i.e. anterior–posterior body axis formation. The signal for polarity originates from the centrosomes and is transmitted to the cell cortex, where it disassembles the actomyosin network. This event leads to symmetry breaking and the establishment of distinct domains of evolutionarily conserved PAR proteins. However, the identity of an essential component that localizes to the centrosomes and promotes symmetry breaking was unknown. Recent work has uncovered that the loss of Aurora A kinase (AIR-1 in C. elegans and hereafter referred to as Aurora A) in the one-cell embryo disrupts stereotypical actomyosin-based cortical flows that occur at the time of polarity establishment. This misregulation of actomyosin flow dynamics results in the occurrence of two polarity axes. Notably, the role of Aurora A in ensuring a single polarity axis is independent of its well-established function in centrosome maturation. The mechanism by which Aurora A directs symmetry breaking is likely through direct regulation of Rho-dependent contractility. In this mini-review, we will discuss the unconventional role of Aurora A kinase in polarity establishment in C. elegans embryos and propose a refined model of centrosome-dependent symmetry breaking.

Platelet-Derived Exosomes Affect the Proliferation and Migration of Human Umbilical Vein Endothelial Cells Via miR-126

2019 ◽  
Vol 17 (4) ◽  
pp. 379-387 ◽  
Author(s):  
Yan Sun ◽  
Xiao-li Liu ◽  
Dai Zhang ◽  
Fang Liu ◽  
Yu-jing Cheng ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Real Time ◽  
Umbilical Vein ◽  
Angiogenic Factors ◽  
Healthy Donors ◽  
And Migration ◽  
Umbilical Vein Endothelial Cells ◽  
Tgf Β1 ◽  
Proliferation And Migration

Background:Intraplaque angiogenesis, the process of generating new blood vessels mediated by endothelial cells, contributes to plaque growth, intraplaque hemorrhage, and thromboembolic events. Platelet-derived Exosomes (PLT-EXOs) affect angiogenesis in multiple ways. The ability of miR-126, one of the best-characterized miRNAs that regulates angiogenesis, carried by PLT-EXOs to influence angiogenesis via the regulation of the proliferation and migration of endothelial cells is unknown. In this study, we aimed to investigate the effects of PLT-EXOs on angiogenesis by Human Umbilical Vein Endothelial Cells (HUVECs).Methods:We evaluated the levels of miR-126 and angiogenic factors in PLT-EXOs from Acute Coronary Syndrome (ACS) patients and healthy donors by real-time Polymerase Chain Reaction (PCR) and western blotting. We incubated HUVECs with PLT-EXOs and measured cell proliferation and migration with the Cell Counting Kit-8 assay and scratch assay, respectively. We also investigated the expression of miR-126 and angiogenic factors in HUVECs after exposure to PLT-EXOs by western blotting and real-time PCR.Results:PLT-EXOs from ACS patients contained higher levels of miR-126 and angiogenic factors, including Vascular Endothelial Growth Factor (VEGF), basic Fibroblast Growth Factor (bFGF), and Transforming Growth Factor Beta 1 (TGF-β1), than those from healthy donors (p<0.05). Moreover, the levels of exosomal miR-126 and angiogenic factors were increased after stimulation with thrombin (p<0.01). HUVEC proliferation and migration were promoted by treatment with activated PLT-EXOs (p<0.01); they were accompanied by the over-expression of miR-126 and angiogenic factors, including VEGF, bFGF, and TGF-β1 (p<0.01).Conclusion:Activated PLT-EXOs promoted the proliferation and migration of HUVECs, and the overexpression of miR-126 and angiogenic factors, thereby elucidating potential new therapeutic targets for intraplaque angiogenesis.

Activation of Aurora A kinase through the FGF1/FGFR signaling axis sustains the stem cell characteristics of glioblastoma cells

2016 ◽  
Vol 344 (2) ◽  
pp. 153-166 ◽  
Author(s):  
Yi-Chao Hsu ◽  
Chien-Yu Kao ◽  
Yu-Fen Chung ◽  
Don-Ching Lee ◽  
Jen-Wei Liu ◽  
...  
Keyword(s):  
Stem Cell ◽  
Aurora A Kinase ◽  
Aurora A ◽  
Glioblastoma Cells ◽  
Fgfr Signaling ◽  
Signaling Axis

scholarly journals MLN8054, an Inhibitor of Aurora A Kinase, Induces Senescence in Human Tumor Cells Both In vitro and In vivo

2010 ◽  
Vol 8 (3) ◽  
pp. 373-384 ◽  
Author(s):  
Jessica J. Huck ◽  
Mengkun Zhang ◽  
Alice McDonald ◽  
Doug Bowman ◽  
Kara M. Hoar ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Human Tumor ◽  
Aurora A Kinase ◽  
Aurora A ◽  
Human Tumor Cells

Thrombospondin-1 Modulates the Angiogenic Phenotype of Human Cerebral Arteriovenous Malformation Endothelial Cells

Neurosurgery ◽  
2011 ◽  
Vol 68 (5) ◽  
pp. 1342-1353 ◽  
Author(s):  
Christopher J. Stapleton ◽  
Don L. Armstrong ◽  
Raphael Zidovetzki ◽  
Charles Y. Liu ◽  
Steven L. Giannotta ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Arteriovenous Malformation ◽  
Immunosorbent Assay ◽  
Cerebral Arteriovenous Malformation ◽  
Enzyme Linked Immunosorbent Assay ◽  
Boyden Chamber ◽  
Mrna Levels ◽  
Tubule Formation ◽  
Thrombospondin 1 ◽  
And Migration

Abstract BACKGROUND: The management of cerebral arteriovenous malformation (AVM) is challenging, and invasive therapies place vital intracranial structures at risk of injury. The development of noninvasive, pharmacologic approaches relies on identifying factors that mediate key angiogenic processes. Previous studies indicate that endothelial cells (ECs) derived from cerebral AVM (AVM-ECs) are distinct from control brain ECs with regard to important angiogenic characteristics. OBJECTIVE: To determine whether thrombospondin-1 (TSP-1), a potent angiostatic factor, regulates critical angiogenic features of AVM-ECs and to identify factors that modulate TSP-1 production in AVM-ECs. METHODS: EC proliferation, migration, and tubule formation were evaluated with bromodeoxyuridine incorporation, Boyden chamber, and Matrigel studies, respectively. TSP-1 and inhibitor of DNA binding/differentiation 1 (Id1) mRNA levels were quantified with microarray and quantitative real-time polymerase chain reaction analyses. TSP-1 protein expression was measured using Western blotting, immunohistochemical, and enzyme-linked immunosorbent assay techniques. The mechanistic link between Id1 and TSP-1 was established through small interfering RNA-mediated knockdown of Id1 in AVM-ECs followed by Western blot and enzyme-linked immunosorbent assay experiments assessing TSP-1 production. RESULTS: AVM-ECs proliferate faster, migrate more quickly, and form disorganized tubules compared with brain ECs. TSP-1 is significantly down-regulated in AVM-ECs. The addition of TSP-1 to AVM-EC cultures normalizes the rate of proliferation and migration and the efficiency of tubule formation, whereas brain ECs are unaffected. Id1 negatively regulates TSP-1 expression in AVM-ECs. CONCLUSION: These data highlight a novel role for TSP-1 in the pathobiology of AVM angiogenesis and provide a context for its use in the clinical management of brain AVMs.

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