1
|
Liu H, Yan R, Li Y, Wang J, Deng Y, Li Y. Dragon's blood attenuates LPS-induced intestinal epithelial barrier dysfunction via upregulation of FAK-DOCK180-Rac1-WAVE2-Arp3 and downregulation of TLR4/NF-κB signaling pathways. J Nat Med 2024; 78:1013-1028. [PMID: 39014275 DOI: 10.1007/s11418-024-01824-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 05/13/2024] [Indexed: 07/18/2024]
Abstract
Inflammation-induced intestinal epithelial barrier (IEB) dysfunction is one of the important reasons for the occurrence and development of intestinal inflammatory-related diseases, including ulcerative colitis (UC), Crohn's disease and necrotizing enterocolitis (NEC). Dragon's blood (DB) is a traditional Chinese medicine and has been clinically used to treat UC. However, the protective mechanism of DB on intestinal inflammatory-related diseases has still not been elucidated. The present study aimed to explore the protection mechanism of DB on IEB dysfunction in rat ileum and human colorectal adenocarcinoma cells (Caco-2)/human umbilical vein endothelial cells (HUVECs) coculture system induced by lipopolysaccharide (LPS). DB could ameliorate rat ileum mucosa morphological injury, reduce the accumulation of lipid-peroxidation products and increase the expression of junction proteins. DB also alleviated LPS-induced Caco-2 cells barrier integrity destruction in Caco-2/ HUVECs coculture system, leading to increased trans-endothelial electrical resistance (TEER), reduced cell permeability, and upregulation of expressions of F-actin and junction proteins. DB contributed to the assembly of actin cytoskeleton by upregulating the FAK-DOCK180-Rac1-WAVE2-Arp3 pathway and contributed to the formation of intercellular junctions by downregulating TLR4-MyD88-NF-κB pathway, thus reversing LPS-induced IEB dysfunction. These novel findings illustrated the potential protective mechanism of DB on intestinal inflammatory-related diseases and might be useful for further clinical application of DB.
Collapse
Affiliation(s)
- Huayan Liu
- School of Life Science, Beijing Institute of Technology, Haidian, Beijing, 100081, China
| | - Ranran Yan
- School of Life Science, Beijing Institute of Technology, Haidian, Beijing, 100081, China
| | - Yongzhi Li
- China Astronaut Research and Training Center, Haidian, Beijing, 100094, China
| | - Jiaping Wang
- China Astronaut Research and Training Center, Haidian, Beijing, 100094, China
| | - Yulin Deng
- School of Life Science, Beijing Institute of Technology, Haidian, Beijing, 100081, China
| | - Yujuan Li
- School of Life Science, Beijing Institute of Technology, Haidian, Beijing, 100081, China.
| |
Collapse
|
2
|
Przyklenk M, Karmacharya S, Bonasera D, Pasanen-Zentz AL, Kmoch S, Paulsson M, Wagener R, Liccardi G, Schiavinato A. ANTXR1 deficiency promotes fibroblast senescence: implications for GAPO syndrome as a progeroid disorder. Sci Rep 2024; 14:9321. [PMID: 38653789 PMCID: PMC11039612 DOI: 10.1038/s41598-024-59901-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 04/16/2024] [Indexed: 04/25/2024] Open
Abstract
ANTXR1 is one of two cell surface receptors mediating the uptake of the anthrax toxin into cells. Despite substantial research on its role in anthrax poisoning and a proposed function as a collagen receptor, ANTXR1's physiological functions remain largely undefined. Pathogenic variants in ANTXR1 lead to the rare GAPO syndrome, named for its four primary features: Growth retardation, Alopecia, Pseudoanodontia, and Optic atrophy. The disease is also associated with a complex range of other phenotypes impacting the cardiovascular, skeletal, pulmonary and nervous systems. Aberrant accumulation of extracellular matrix components and fibrosis are considered to be crucial components in the pathogenesis of GAPO syndrome, contributing to the shortened life expectancy of affected individuals. Nonetheless, the specific mechanisms connecting ANTXR1 deficiency to the clinical manifestations of GAPO syndrome are largely unexplored. In this study, we present evidence that ANTXR1 deficiency initiates a senescent phenotype in human fibroblasts, correlating with defects in nuclear architecture and actin dynamics. We provide novel insights into ANTXR1's physiological functions and propose GAPO syndrome to be reconsidered as a progeroid disorder highlighting an unexpected role for an integrin-like extracellular matrix receptor in human aging.
Collapse
Affiliation(s)
- Matthias Przyklenk
- Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
| | - Shreya Karmacharya
- Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
| | - Debora Bonasera
- Genetic Instability, Cell Death and Inflammation Laboratory, Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
| | - Arthur-Lauri Pasanen-Zentz
- Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
| | - Stanislav Kmoch
- Research Unit of Rare Diseases, Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Mats Paulsson
- Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Raimund Wagener
- Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
| | - Gianmaria Liccardi
- Genetic Instability, Cell Death and Inflammation Laboratory, Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
| | - Alvise Schiavinato
- Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany.
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.
- Department of Pediatrics and Adolescent Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.
| |
Collapse
|
3
|
Lin AJ, Sihorwala AZ, Belardi B. Engineering Tissue-Scale Properties with Synthetic Cells: Forging One from Many. ACS Synth Biol 2023; 12:1889-1907. [PMID: 37417657 PMCID: PMC11017731 DOI: 10.1021/acssynbio.3c00061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
In metazoans, living cells achieve capabilities beyond individual cell functionality by assembling into multicellular tissue structures. These higher-order structures represent dynamic, heterogeneous, and responsive systems that have evolved to regenerate and coordinate their actions over large distances. Recent advances in constructing micrometer-sized vesicles, or synthetic cells, now point to a future where construction of synthetic tissue can be pursued, a boon to pressing material needs in biomedical implants, drug delivery systems, adhesives, filters, and storage devices, among others. To fully realize the potential of synthetic tissue, inspiration has been and will continue to be drawn from new molecular findings on its natural counterpart. In this review, we describe advances in introducing tissue-scale features into synthetic cell assemblies. Beyond mere complexation, synthetic cells have been fashioned with a variety of natural and engineered molecular components that serve as initial steps toward morphological control and patterning, intercellular communication, replication, and responsiveness in synthetic tissue. Particular attention has been paid to the dynamics, spatial constraints, and mechanical strengths of interactions that drive the synthesis of this next-generation material, describing how multiple synthetic cells can act as one.
Collapse
Affiliation(s)
- Alexander J Lin
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Ahmed Z Sihorwala
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Brian Belardi
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| |
Collapse
|
4
|
Genomic instability caused by Arp2/3 complex inactivation results in micronucleus biogenesis and cellular senescence. PLoS Genet 2023; 19:e1010045. [PMID: 36706133 PMCID: PMC9907832 DOI: 10.1371/journal.pgen.1010045] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/08/2023] [Accepted: 01/10/2023] [Indexed: 01/28/2023] Open
Abstract
The Arp2/3 complex is an actin nucleator with well-characterized activities in cell morphogenesis and movement, but its roles in nuclear processes are relatively understudied. We investigated how the Arp2/3 complex affects genomic integrity and cell cycle progression using mouse fibroblasts containing an inducible knockout (iKO) of the ArpC2 subunit. We show that permanent Arp2/3 complex ablation results in DNA damage, the formation of cytosolic micronuclei, and cellular senescence. Micronuclei arise in ArpC2 iKO cells due to chromatin segregation defects during mitosis and premature mitotic exits. Such phenotypes are explained by the presence of damaged DNA fragments that fail to attach to the mitotic spindle, abnormalities in actin assembly during metaphase, and asymmetric microtubule architecture during anaphase. In the nuclei of Arp2/3-depleted cells, the tumor suppressor p53 is activated and the cell cycle inhibitor Cdkn1a/p21 mediates a G1 arrest. In the cytosol, micronuclei are recognized by the DNA sensor cGAS, which is important for stimulating a STING- and IRF3-associated interferon response. These studies establish functional requirements for the mammalian Arp2/3 complex in mitotic spindle organization and genome stability. They also expand our understanding of the mechanisms leading to senescence and suggest that cytoskeletal dysfunction is an underlying factor in biological aging.
Collapse
|
5
|
Rodríguez-Fernández JL, Criado-García O. A meta-analysis indicates that the regulation of cell motility is a non-intrinsic function of chemoattractant receptors that is governed independently of directional sensing. Front Immunol 2022; 13:1001086. [PMID: 36341452 PMCID: PMC9630654 DOI: 10.3389/fimmu.2022.1001086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 10/03/2022] [Indexed: 11/30/2022] Open
Abstract
Chemoattraction, defined as the migration of a cell toward a source of a chemical gradient, is controlled by chemoattractant receptors. Chemoattraction involves two basic activities, namely, directional sensing, a molecular mechanism that detects the direction of a source of chemoattractant, and actin-based motility, which allows the migration of a cell towards it. Current models assume first, that chemoattractant receptors govern both directional sensing and motility (most commonly inducing an increase in the migratory speed of the cells, i.e. chemokinesis), and, second, that the signaling pathways controlling both activities are intertwined. We performed a meta-analysis to reassess these two points. From this study emerge two main findings. First, although many chemoattractant receptors govern directional sensing, there are also receptors that do not regulate cell motility, suggesting that is the ability to control directional sensing, not motility, that best defines a chemoattractant receptor. Second, multiple experimental data suggest that receptor-controlled directional sensing and motility can be controlled independently. We hypothesize that this independence may be based on the existence of separated signalling modules that selectively govern directional sensing and motility in chemotactic cells. Together, the information gathered can be useful to update current models representing the signalling from chemoattractant receptors. The new models may facilitate the development of strategies for a more effective pharmacological modulation of chemoattractant receptor-controlled chemoattraction in health and disease.
Collapse
|
6
|
The Actin Cytoskeleton Responds to Inflammatory Cues and Alters Macrophage Activation. Cells 2022; 11:cells11111806. [PMID: 35681501 PMCID: PMC9180445 DOI: 10.3390/cells11111806] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/25/2022] [Accepted: 05/26/2022] [Indexed: 02/01/2023] Open
Abstract
Much remains to be learned about the molecular mechanisms underlying a class of human disorders called actinopathies. These genetic disorders are characterized by loss-of-function mutations in actin-associated proteins that affect immune cells, leading to human immunopathology. However, much remains to be learned about how cytoskeletal dysregulation promotes immunological dysfunction. The current study reveals that the macrophage actin cytoskeleton responds to LPS/IFNγ stimulation in a biphasic manner that involves cellular contraction followed by cellular spreading. Myosin II inhibition by blebbistatin blocks the initial contraction phase and lowers iNOS protein levels and nitric oxide secretion. Conversely, conditional deletion of Arp2/3 complex in macrophages attenuates spreading and increases nitric oxide secretion. However, iNOS transcription is not altered by loss of myosin II or Arp2/3 function, suggesting post-transcriptional regulation of iNOS by the cytoskeleton. Consistent with this idea, proteasome inhibition reverses the effects of blebbistatin and rescues iNOS protein levels. Arp2/3-deficient macrophages demonstrate two additional phenotypes: defective MHCII surface localization, and depressed secretion of the T cell chemokine CCL22. These data suggest that interplay between myosin II and Arp2/3 influences macrophage activity, and potentially impacts adaptive-innate immune coordination. Disrupting this balance could have detrimental impacts, particularly in the context of Arp2/3-associated actinopathies.
Collapse
|
7
|
Modulation of the Mucosa-Associated Microbiome Linked to the PTPN2 Risk Gene in Patients with Primary Sclerosing Cholangitis and Ulcerative Colitis. Microorganisms 2021; 9:microorganisms9081752. [PMID: 34442830 PMCID: PMC8399714 DOI: 10.3390/microorganisms9081752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/31/2021] [Accepted: 08/13/2021] [Indexed: 12/15/2022] Open
Abstract
Gut microbiota appears to be involved in the pathogenesis of primary sclerosing cholangitis (PSC). The protein tyrosine phosphatase nonreceptor 2 (PTPN2) gene risk variant rs1893217 is associated with gut dysbiosis in inflammatory bowel disease (IBD), and PTPN2 was mentioned as a possible risk gene for PSC. This study assessed the microbial profile of ulcerative colitis (UC) patients with PSC and without PSC (non-PSC). Additionally, effects of the PTPN2 risk variant were assessed. In total, 216 mucosal samples from ileum, colon, and rectum were collected from 7 PSC and 42 non-PSC patients, as well as 28 control subjects (non-IBD). The microbial composition was derived from 16S rRNA sequencing data. Overall, bacterial richness was highest in PSC patients, who also had a higher relative abundance of the genus Roseburia compared to non-PSC, as well as Haemophilus, Fusobacterium, Bifidobacterium, and Actinobacillus compared to non-IBD, as well as a lower relative abundance of Bacteroides compared to non-PSC and non-IBD, respectively. After exclusion of patients with the PTPN2 risk variant, Brachyspira was higher in PSC compared to non-PSC, while, solely in colon samples, Eubacterium and Tepidimonas were higher in PSC vs. non-IBD. In conclusion, this study underlines the presence of gut mucosa-associated microbiome changes in PSC patients and rather weakens the role of PTPN2 as a PSC risk gene.
Collapse
|
8
|
Articular Chondrocyte Phenotype Regulation through the Cytoskeleton and the Signaling Processes That Originate from or Converge on the Cytoskeleton: Towards a Novel Understanding of the Intersection between Actin Dynamics and Chondrogenic Function. Int J Mol Sci 2021; 22:ijms22063279. [PMID: 33807043 PMCID: PMC8004672 DOI: 10.3390/ijms22063279] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 02/08/2023] Open
Abstract
Numerous studies have assembled a complex picture, in which extracellular stimuli and intracellular signaling pathways modulate the chondrocyte phenotype. Because many diseases are mechanobiology-related, this review asked to what extent phenotype regulators control chondrocyte function through the cytoskeleton and cytoskeleton-regulating signaling processes. Such information would generate leverage for advanced articular cartilage repair. Serial passaging, pro-inflammatory cytokine signaling (TNF-α, IL-1α, IL-1β, IL-6, and IL-8), growth factors (TGF-α), and osteoarthritis not only induce dedifferentiation but also converge on RhoA/ROCK/Rac1/mDia1/mDia2/Cdc42 to promote actin polymerization/crosslinking for stress fiber (SF) formation. SF formation takes center stage in phenotype control, as both SF formation and SOX9 phosphorylation for COL2 expression are ROCK activity-dependent. Explaining how it is molecularly possible that dedifferentiation induces low COL2 expression but high SF formation, this review theorized that, in chondrocyte SOX9, phosphorylation by ROCK might effectively be sidelined in favor of other SF-promoting ROCK substrates, based on a differential ROCK affinity. In turn, actin depolymerization for redifferentiation would “free-up” ROCK to increase COL2 expression. Moreover, the actin cytoskeleton regulates COL1 expression, modulates COL2/aggrecan fragment generation, and mediates a fibrogenic/catabolic expression profile, highlighting that actin dynamics-regulating processes decisively control the chondrocyte phenotype. This suggests modulating the balance between actin polymerization/depolymerization for therapeutically controlling the chondrocyte phenotype.
Collapse
|
9
|
Dimchev V, Lahmann I, Koestler SA, Kage F, Dimchev G, Steffen A, Stradal TEB, Vauti F, Arnold HH, Rottner K. Induced Arp2/3 Complex Depletion Increases FMNL2/3 Formin Expression and Filopodia Formation. Front Cell Dev Biol 2021; 9:634708. [PMID: 33598464 PMCID: PMC7882613 DOI: 10.3389/fcell.2021.634708] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 01/07/2021] [Indexed: 01/12/2023] Open
Abstract
The Arp2/3 complex generates branched actin filament networks operating in cell edge protrusion and vesicle trafficking. Here we employ a conditional knockout mouse model permitting tissue- or cell-type specific deletion of the murine Actr3 gene (encoding Arp3). A functional Actr3 gene appeared essential for fibroblast viability and growth. Thus, we developed cell lines for exploring the consequences of acute, tamoxifen-induced Actr3 deletion causing near-complete loss of functional Arp2/3 complex expression as well as abolished lamellipodia formation and membrane ruffling, as expected. Interestingly, Arp3-depleted cells displayed enhanced rather than reduced cell spreading, employing numerous filopodia, and showed little defects in the rates of random cell migration. However, both exploration of new space by individual cells and collective migration were clearly compromised by the incapability to efficiently maintain directionality of migration, while the principal ability to chemotax was only moderately affected. Examination of actin remodeling at the cell periphery revealed reduced actin turnover rates in Arp2/3-deficient cells, clearly deviating from previous sequestration approaches. Most surprisingly, induced removal of Arp2/3 complexes reproducibly increased FMNL formin expression, which correlated with the explosive induction of filopodia formation. Our results thus highlight both direct and indirect effects of acute Arp2/3 complex removal on actin cytoskeleton regulation.
Collapse
Affiliation(s)
- Vanessa Dimchev
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany.,Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ines Lahmann
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Stefan A Koestler
- Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Frieda Kage
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany.,Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Georgi Dimchev
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany.,Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Anika Steffen
- Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Theresia E B Stradal
- Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Franz Vauti
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Hans-Henning Arnold
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Klemens Rottner
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany.,Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
| |
Collapse
|
10
|
Abstract
Cryptococcus yeast species typically display characteristics of opportunistic pathogens, with the exception of C. gattii, which can cause life-threatening respiratory and disseminated brain infections in otherwise healthy people. The pathogenesis of C. gattii is not well understood, but an important characteristic is that C. gattii is capable of evading host cell-mediated immune defenses initiated by DCs. Here, we report that when virulent C. gattii becomes ingested by a DC, the intracellular compartment containing the fungi is covered by a persistent protein cage structure consisting of F-actin. This F-actin cage acts as a barrier to prevent interaction with other intracellular compartments, and as a result, the DC fails to kill the fungi and activate important cell-mediated immune responses. We propose that this unique immune evasion mechanism permits C. gattii to remain unchallenged within host cells, leading to persistent infection. Cryptococcus gattii is a major cause of life-threatening mycosis in immunocompetent individuals and responsible for the ongoing epidemic outbreak of cryptococcosis in the Pacific Northwest of North America. This deadly fungus is known to evade important host immune responses, including dendritic cell (DC) maturation and concomitant T cell immunity, via immune evasion mechanisms that remain unclear. Here, we demonstrate that primary human DCs phagocytose C. gattii but the maturation of phagosomes to phagolysosomes was blocked as a result of sustained filamentous actin (F-actin) that entrapped and concealed the phagosomes from recognition. Superresolution structured illumination microscopy (SR-SIM) revealed that the persistent phagosomal F-actin formed a cage-like structure that sterically hindered and functionally blocked the fusion of lysosomes. Blocking lysosome fusion was sufficient to inhibit phagosomal acidification and subsequent intracellular fungal killing by DCs. Retention of phagosomal F-actin by C. gattii also caused DC immunoparalysis. Disrupting the retained F-actin cage with cytochalasin D not only restored DC phagosomal maturation but also promoted DC costimulatory maturation and robust T cell activation and proliferation. Collectively, these results reveal a unique mechanism of DC immune evasion that enhances intracellular fungal pathogenicity and may explain suppressed cell-mediated immunity.
Collapse
|
11
|
Papalazarou V, Swaminathan K, Jaber-Hijazi F, Spence H, Lahmann I, Nixon C, Salmeron-Sanchez M, Arnold HH, Rottner K, Machesky LM. The Arp2/3 complex is crucial for colonisation of the mouse skin by melanoblasts. Development 2020; 147:dev194555. [PMID: 33028610 PMCID: PMC7687863 DOI: 10.1242/dev.194555] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/22/2020] [Indexed: 01/10/2023]
Abstract
The Arp2/3 complex is essential for the assembly of branched filamentous actin, but its role in physiology and development is surprisingly little understood. Melanoblasts deriving from the neural crest migrate along the developing embryo and traverse the dermis to reach the epidermis, colonising the skin and eventually homing within the hair follicles. We have previously established that Rac1 and Cdc42 direct melanoblast migration in vivo We hypothesised that the Arp2/3 complex might be the main downstream effector of these small GTPases. Arp3 depletion in the melanocyte lineage results in severe pigmentation defects in dorsal and ventral regions of the mouse skin. Arp3 null melanoblasts demonstrate proliferation and migration defects and fail to elongate as their wild-type counterparts. Conditional deletion of Arp3 in primary melanocytes causes improper proliferation, spreading, migration and adhesion to extracellular matrix. Collectively, our results suggest that the Arp2/3 complex is absolutely indispensable in the melanocyte lineage in mouse development, and indicate a significant role in developmental processes that require tight regulation of actin-mediated motility.
Collapse
Affiliation(s)
- Vassilis Papalazarou
- CRUK Beatson Institute, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD, UK
- Institute of Cancer Sciences, University of Glasgow, Garscube Campus, Switchback Road, Bearsden, Glasgow G61 1QH, UK
- Centre for the Cellular Microenvironment, University of Glasgow, Glasgow G12 8LT, UK
| | - Karthic Swaminathan
- CRUK Beatson Institute, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Farah Jaber-Hijazi
- CRUK Beatson Institute, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Heather Spence
- CRUK Beatson Institute, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Ines Lahmann
- Cell and Molecular Biology, Institute of Biochemistry and Biotechnology, Technische Universität Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany
| | - Colin Nixon
- CRUK Beatson Institute, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | | | - Hans-Henning Arnold
- Cell and Molecular Biology, Institute of Biochemistry and Biotechnology, Technische Universität Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany
| | - Klemens Rottner
- Division of Molecular Cell Biology, Zoological Institute, Technische Universität Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Laura M Machesky
- CRUK Beatson Institute, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD, UK
- Institute of Cancer Sciences, University of Glasgow, Garscube Campus, Switchback Road, Bearsden, Glasgow G61 1QH, UK
| |
Collapse
|
12
|
Svitkina TM. Actin Cell Cortex: Structure and Molecular Organization. Trends Cell Biol 2020; 30:556-565. [PMID: 32278656 PMCID: PMC7566779 DOI: 10.1016/j.tcb.2020.03.005] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 03/11/2020] [Accepted: 03/19/2020] [Indexed: 12/20/2022]
Abstract
The actin cytoskeleton consists of structurally and biochemically different actin filament arrays. Among them, the actin cortex is thought to have key roles in cell mechanics, but remains a poorly characterized part of the actin cytoskeleton. The cell cortex is typically defined as a thin layer of actin meshwork that uniformly underlies the plasma membrane of the entire cell. However, this definition applies only to specific cases. In general, the cortex structure and subcellular distribution vary significantly across cell types and physiological states of the cell. In this review, I focus on our current knowledge of the structure and molecular composition of the cell cortex.
Collapse
Affiliation(s)
- Tatyana M Svitkina
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
13
|
Tessier S, Doolittle AC, Sao K, Rotty JD, Bear JE, Ulici V, Loeser RF, Shapiro IM, Diekman BO, Risbud MV. Arp2/3 inactivation causes intervertebral disc and cartilage degeneration with dysregulated TonEBP-mediated osmoadaptation. JCI Insight 2020; 5:131382. [PMID: 31961823 DOI: 10.1172/jci.insight.131382] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 01/15/2020] [Indexed: 01/01/2023] Open
Abstract
Extracellular matrix and osmolarity influence the development and homeostasis of skeletal tissues through Rho GTPase-mediated alteration of the actin cytoskeleton. This study investigated whether the actin-branching Arp2/3 complex, a downstream effector of the Rho GTPases Cdc42 and Rac1, plays a critical role in maintaining the health of matrix-rich and osmotically loaded intervertebral discs and cartilage. Mice with constitutive intervertebral disc- and cartilage-specific deletion of the critical Arp2/3 subunit Arpc2 (Col2-Cre; Arpc2fl/fl) developed chondrodysplasia and spinal defects. Since these mice did not survive to adulthood, we generated mice with inducible Arpc2 deletion in disc and cartilage (Acan-CreERT2; Arpc2fl/fl). Inactivation of Arp2/3 at skeletal maturity resulted in growth plate closure, loss of proteoglycan content in articular cartilage, and degenerative changes in the intervertebral disc at 1 year of age. Chondrocytes with Arpc2 deletion showed compromised cell spreading on both collagen and fibronectin. Pharmacological inhibition of Cdc42 and Arp2/3 prevented the osmoadaptive transcription factor TonEBP/NFAT5 from recruiting cofactors in response to a hyperosmolarity challenge. Together, these findings suggest that Arp2/3 plays a critical role in cartilaginous tissues through the regulation of cell-extracellular matrix interactions and modulation of TonEBP-mediated osmoadaptation.
Collapse
Affiliation(s)
- Steven Tessier
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College
| | - Alexandra C Doolittle
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College.,Graduate Program in Cell Biology and Regenerative Medicine, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Kimheak Sao
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College.,Graduate Program in Cell Biology and Regenerative Medicine, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Jeremy D Rotty
- Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,Department of Cell Biology and Physiology.,UNC Lineberger Comprehensive Cancer Center
| | - James E Bear
- Department of Cell Biology and Physiology.,UNC Lineberger Comprehensive Cancer Center
| | - Veronica Ulici
- Thurston Arthritis Research Center, and.,Division of Rheumatology, Allergy, and Immunology, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Richard F Loeser
- Thurston Arthritis Research Center, and.,Division of Rheumatology, Allergy, and Immunology, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Irving M Shapiro
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College.,Graduate Program in Cell Biology and Regenerative Medicine, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Brian O Diekman
- Division of Rheumatology, Allergy, and Immunology, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill and Raleigh, North Carolina, USA
| | - Makarand V Risbud
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College.,Graduate Program in Cell Biology and Regenerative Medicine, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| |
Collapse
|
14
|
Chánez-Paredes S, Montoya-García A, Schnoor M. Cellular and pathophysiological consequences of Arp2/3 complex inhibition: role of inhibitory proteins and pharmacological compounds. Cell Mol Life Sci 2019; 76:3349-3361. [PMID: 31073744 PMCID: PMC11105272 DOI: 10.1007/s00018-019-03128-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 04/30/2019] [Accepted: 05/02/2019] [Indexed: 02/06/2023]
Abstract
The actin-related protein complex 2/3 (Arp2/3) generates branched actin networks important for many cellular processes such as motility, vesicular trafficking, cytokinesis, and intercellular junction formation and stabilization. Activation of Arp2/3 requires interaction with actin nucleation-promoting factors (NPFs). Regulation of Arp2/3 activity is achieved by endogenous inhibitory proteins through direct binding to Arp2/3 and competition with NPFs or by binding to Arp2/3-induced actin filaments and disassembly of branched actin networks. Arp2/3 inhibition has recently garnered more attention as it has been associated with attenuation of cancer progression, neurotoxic effects during drug abuse, and pathogen invasion of host cells. In this review, we summarize current knowledge on expression, inhibitory mechanisms and function of endogenous proteins able to inhibit Arp2/3 such as coronins, GMFs, PICK1, gadkin, and arpin. Moreover, we discuss cellular consequences of pharmacological Arp2/3 inhibition.
Collapse
Affiliation(s)
- Sandra Chánez-Paredes
- Department for Molecular Biomedicine, CINVESTAV-IPN, Av. IPN 2508, San Pedro Zacatenco, GAM, 07360, Mexico City, Mexico
| | - Armando Montoya-García
- Department for Molecular Biomedicine, CINVESTAV-IPN, Av. IPN 2508, San Pedro Zacatenco, GAM, 07360, Mexico City, Mexico
| | - Michael Schnoor
- Department for Molecular Biomedicine, CINVESTAV-IPN, Av. IPN 2508, San Pedro Zacatenco, GAM, 07360, Mexico City, Mexico.
| |
Collapse
|
15
|
Molinie N, Rubtsova SN, Fokin A, Visweshwaran SP, Rocques N, Polesskaya A, Schnitzler A, Vacher S, Denisov EV, Tashireva LA, Perelmuter VM, Cherdyntseva NV, Bièche I, Gautreau AM. Cortical branched actin determines cell cycle progression. Cell Res 2019; 29:432-445. [PMID: 30971746 PMCID: PMC6796858 DOI: 10.1038/s41422-019-0160-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 03/06/2019] [Indexed: 12/30/2022] Open
Abstract
The actin cytoskeleton generates and senses forces. Here we report that branched actin networks from the cell cortex depend on ARPC1B-containing Arp2/3 complexes and that they are specifically monitored by type I coronins to control cell cycle progression in mammary epithelial cells. Cortical ARPC1B-dependent branched actin networks are regulated by the RAC1/WAVE/ARPIN pathway and drive lamellipodial protrusions. Accordingly, we uncover that the duration of the G1 phase scales with migration persistence in single migrating cells. Moreover, cortical branched actin more generally determines S-phase entry by integrating soluble stimuli such as growth factors and mechanotransduction signals, ensuing from substratum rigidity or stretching of epithelial monolayers. Many tumour cells lose this dependence for cortical branched actin. But the RAC1-transformed tumour cells stop cycling upon Arp2/3 inhibition. Among all genes encoding Arp2/3 subunits, ARPC1B overexpression in tumours is associated with the poorest metastasis-free survival in breast cancer patients. Arp2/3 specificity may thus provide diagnostic and therapeutic opportunities in cancer.
Collapse
Affiliation(s)
- Nicolas Molinie
- BIOC, Ecole polytechnique, CNRS, IP Paris, Palaiseau, France
| | - Svetlana N Rubtsova
- BIOC, Ecole polytechnique, CNRS, IP Paris, Palaiseau, France.,N.N. Blokhin National Medical Research Center of Oncology, Moscow, Russia
| | - Artem Fokin
- BIOC, Ecole polytechnique, CNRS, IP Paris, Palaiseau, France
| | | | | | - Anna Polesskaya
- BIOC, Ecole polytechnique, CNRS, IP Paris, Palaiseau, France
| | | | - Sophie Vacher
- Department of Genetics, Institut Curie, Paris, France
| | - Evgeny V Denisov
- Tomsk National Research Medical Center, Tomsk, Russia.,Tomsk State University, Tomsk, Russia
| | | | | | - Nadezhda V Cherdyntseva
- Tomsk National Research Medical Center, Tomsk, Russia.,Tomsk State University, Tomsk, Russia
| | - Ivan Bièche
- Department of Genetics, Institut Curie, Paris, France
| | - Alexis M Gautreau
- BIOC, Ecole polytechnique, CNRS, IP Paris, Palaiseau, France. .,School of Biological and Medical Physics, Moscow Institute of Physics and Technology, Dolgoprudny, Russia.
| |
Collapse
|
16
|
Actin related protein 3 (ARP3) promotes apoptosis of intestinal epithelial cells in ulcerative colitis. Pathol Res Pract 2019; 215:235-242. [DOI: 10.1016/j.prp.2018.10.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/15/2018] [Accepted: 10/17/2018] [Indexed: 01/26/2023]
|
17
|
Innocenti M. New insights into the formation and the function of lamellipodia and ruffles in mesenchymal cell migration. Cell Adh Migr 2018. [PMID: 29513145 DOI: 10.1080/19336918.2018.1448352] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Lamellipodia and ruffles are veil-shaped cell protrusions composed of a highly branched actin filament meshwork assembled by the Arp2/3 complex. These structures not only hallmark the leading edge of cells adopting the adhesion-based mesenchymal mode of migration but are also thought to drive cell movement. Although regarded as textbook knowledge, the mechanism of formation of lamellipodia and ruffles has been revisited in the last years leveraging new technologies. Furthermore, recent observations have also challenged our current view of the function of lamellipodia and ruffles in mesenchymal cell migration. Here, I review this literature and compare it with older studies to highlight the controversies and the outstanding open issues in the field. Moreover, I outline simple and plausible explanations to reconcile conflicting results and conclusions. Finally, I integrate the mechanisms regulating actin-based protrusion in a unifying model that accounts for random and ballistic mesenchymal cell migration.
Collapse
Affiliation(s)
- Metello Innocenti
- a Division of Molecular Genetics, The Netherlands Cancer Institute , Plesmanlaan 121, Amsterdam , CX , The Netherlands
| |
Collapse
|
18
|
Swaney KF, Li R. Function and regulation of the Arp2/3 complex during cell migration in diverse environments. Curr Opin Cell Biol 2016; 42:63-72. [PMID: 27164504 DOI: 10.1016/j.ceb.2016.04.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 04/11/2016] [Indexed: 02/06/2023]
Abstract
As the first de novo actin nucleator discovered, the Arp2/3 complex has been a central player in models of protrusive force production via the dynamic actin network. Here, we review recent studies on the functional role of the Arp2/3 complex in the migration of diverse cell types in different migratory environments. These findings have revealed an unexpected level of plasticity, both in how cells rely on the Arp2/3 complex for migration and other physiological functions and in the intricate modulation of the Arp2/3 complex by other actin regulators and upstream signaling cascades.
Collapse
Affiliation(s)
- Kristen F Swaney
- Department of Cell Biology, Johns Hopkins University School of Medicine, 855 North Wolfe Street, 450 Rangos Building, Baltimore, MD 21205, USA; Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, 3400 North Charles Street, 100 Croft Hall, Baltimore, MD 21218, USA.
| | - Rong Li
- Department of Cell Biology, Johns Hopkins University School of Medicine, 855 North Wolfe Street, 450 Rangos Building, Baltimore, MD 21205, USA; Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, 3400 North Charles Street, 100 Croft Hall, Baltimore, MD 21218, USA
| |
Collapse
|
19
|
Swaminathan V, Fischer RS, Waterman CM. The FAK-Arp2/3 interaction promotes leading edge advance and haptosensing by coupling nascent adhesions to lamellipodia actin. Mol Biol Cell 2016; 27:1085-100. [PMID: 26842895 PMCID: PMC4814217 DOI: 10.1091/mbc.e15-08-0590] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 01/22/2016] [Indexed: 02/07/2023] Open
Abstract
Focal adhesion kinase (FAK) is an important regulator of focal adhesion dynamics during cell migration. Distinct functions of FAK—kinase activation and Arp2/3 binding—enable cells to mechanosense or haptotax during spreading and migration. Cell migration is initiated in response to biochemical or physical cues in the environment that promote actin-mediated lamellipodial protrusion followed by the formation of nascent integrin adhesions (NAs) within the protrusion to drive leading edge advance. Although FAK is known to be required for cell migration through effects on focal adhesions, its role in NA formation and lamellipodial dynamics is unclear. Live-cell microscopy of FAK−/− cells with expression of phosphorylation deficient or a FERM-domain mutant deficient in Arp2/3 binding revealed a requirement for FAK in promoting the dense formation, transient stabilization, and timely turnover of NA within lamellipodia to couple actin-driven protrusion to adhesion and advance of the leading edge. Phosphorylation on Y397 of FAK promotes dense NA formation but is dispensable for transient NA stabilization and leading edge advance. In contrast, transient NA stabilization and advance of the cell edge requires FAK–Arp2/3 interaction, which promotes Arp2/3 localization to NA and reduces FAK activity. Haptosensing of extracellular matrix (ECM) concentration during migration requires the interaction between FAK and Arp2/3, whereas FAK phosphorylation modulates mechanosensing of ECM stiffness during spreading. Taken together, our results show that mechanistically separable functions of FAK in NA are required for cells to distinguish distinct properties of their environment during migration.
Collapse
Affiliation(s)
- Vinay Swaminathan
- Cell Biology and Physiology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8019
| | - R S Fischer
- Cell Biology and Physiology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8019
| | - Clare M Waterman
- Cell Biology and Physiology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8019
| |
Collapse
|
20
|
Skau CT, Waterman CM. Specification of Architecture and Function of Actin Structures by Actin Nucleation Factors. Annu Rev Biophys 2016; 44:285-310. [PMID: 26098516 DOI: 10.1146/annurev-biophys-060414-034308] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The actin cytoskeleton is essential for diverse processes in mammalian cells; these processes range from establishing cell polarity to powering cell migration to driving cytokinesis to positioning intracellular organelles. How these many functions are carried out in a spatiotemporally regulated manner in a single cytoplasm has been the subject of much study in the cytoskeleton field. Recent work has identified a host of actin nucleation factors that can build architecturally diverse actin structures. The biochemical properties of these factors, coupled with their cellular location, likely define the functional properties of actin structures. In this article, we describe how recent advances in cell biology and biochemistry have begun to elucidate the role of individual actin nucleation factors in generating distinct cellular structures. We also consider how the localization and orientation of actin nucleation factors, in addition to their kinetic properties, are critical to their ability to build a functional actin cytoskeleton.
Collapse
Affiliation(s)
- Colleen T Skau
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892; ,
| | | |
Collapse
|
21
|
Wright CE, Kushner EJ, Du Q, Bautch VL. LGN Directs Interphase Endothelial Cell Behavior via the Microtubule Network. PLoS One 2015; 10:e0138763. [PMID: 26398908 PMCID: PMC4580422 DOI: 10.1371/journal.pone.0138763] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 09/03/2015] [Indexed: 12/24/2022] Open
Abstract
Angiogenic sprouts require coordination of endothelial cell (EC) behaviors as they extend and branch. Microtubules influence behaviors such as cell migration and cell-cell interactions via regulated growth and shrinkage. Here we investigated the role of the mitotic polarity protein LGN in EC behaviors and sprouting angiogenesis. Surprisingly, reduced levels of LGN did not affect oriented division of EC within a sprout, but knockdown perturbed overall sprouting. At the cell level, LGN knockdown compromised cell-cell adhesion and migration. EC with reduced LGN levels also showed enhanced growth and stabilization of microtubules that correlated with perturbed migration. These results fit a model whereby LGN influences interphase microtubule dynamics in endothelial cells to regulate migration, cell adhesion, and sprout extension, and reveal a novel non-mitotic role for LGN in sprouting angiogenesis.
Collapse
Affiliation(s)
- Catherine E. Wright
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Erich J. Kushner
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Quansheng Du
- Department of Neurology, Institute of Molecular Medicine and Genetics, Georgia Regents University, Augusta, Georgia, United States of America
| | - Victoria L. Bautch
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
- McAllister Heart Institute, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
- * E-mail:
| |
Collapse
|
22
|
Haynes EM, Asokan SB, King SJ, Johnson HE, Haugh JM, Bear JE. GMFβ controls branched actin content and lamellipodial retraction in fibroblasts. J Cell Biol 2015; 209:803-12. [PMID: 26101216 PMCID: PMC4477851 DOI: 10.1083/jcb.201501094] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The primary activity of GMFβ in vivo is actin branch disassembly (and not inhibition of Arp2/3 activation), and this activity plays an important role in lamellipodial dynamics and directional migration toward ECM cues. The lamellipodium is an important structure for cell migration containing branched actin nucleated via the Arp2/3 complex. The formation of branched actin is relatively well studied, but less is known about its disassembly and how this influences migration. GMF is implicated in both Arp2/3 debranching and inhibition of Arp2/3 activation. Modulation of GMFβ, a ubiquitous GMF isoform, by depletion or overexpression resulted in changes in lamellipodial dynamics, branched actin content, and migration. Acute pharmacological inhibition of Arp2/3 by CK-666, coupled to quantitative live-cell imaging of the complex, showed that depletion of GMFβ decreased the rate of branched actin disassembly. These data, along with mutagenesis studies, suggest that debranching (not inhibition of Arp2/3 activation) is a primary activity of GMFβ in vivo. Furthermore, depletion or overexpression of GMFβ disrupted the ability of cells to directionally migrate to a gradient of fibronectin (haptotaxis). These data suggest that debranching by GMFβ plays an important role in branched actin regulation, lamellipodial dynamics, and directional migration.
Collapse
Affiliation(s)
- Elizabeth M Haynes
- UNC Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27514 Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Sreeja B Asokan
- UNC Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27514 Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Samantha J King
- UNC Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27514 Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Heath E Johnson
- Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695
| | - Jason M Haugh
- Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695
| | - James E Bear
- UNC Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27514 Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 Howard Hughes Medical Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| |
Collapse
|
23
|
Ricci C, Ferri N. Naturally occurring PDGF receptor inhibitors with potential anti-atherosclerotic properties. Vascul Pharmacol 2015; 70:1-7. [DOI: 10.1016/j.vph.2015.02.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 02/18/2015] [Accepted: 02/20/2015] [Indexed: 01/03/2023]
|
24
|
Andrade DM, Clausen MP, Keller J, Mueller V, Wu C, Bear JE, Hell SW, Lagerholm BC, Eggeling C. Cortical actin networks induce spatio-temporal confinement of phospholipids in the plasma membrane--a minimally invasive investigation by STED-FCS. Sci Rep 2015; 5:11454. [PMID: 26118385 PMCID: PMC4484492 DOI: 10.1038/srep11454] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 05/20/2015] [Indexed: 11/09/2022] Open
Abstract
Important discoveries in the last decades have changed our view of the plasma membrane organisation. Specifically, the cortical cytoskeleton has emerged as a key modulator of the lateral diffusion of membrane proteins. Cytoskeleton-dependent compartmentalised lipid diffusion has been proposed, but this concept remains controversial because this phenomenon has thus far only been observed with artefact-prone probes in combination with a single technique: single particle tracking. In this paper, we report the first direct observation of compartmentalised phospholipid diffusion in the plasma membrane of living cells using a minimally invasive, fluorescent dye labelled lipid analogue. These observations were made using optical STED nanoscopy in combination with fluorescence correlation spectroscopy (STED-FCS), a technique which allows the study of membrane dynamics on a sub-millisecond time-scale and with a spatial resolution of down to 40 nm. Specifically, we find that compartmentalised phospholipid diffusion depends on the cortical actin cytoskeleton, and that this constrained diffusion is directly dependent on the F-actin branching nucleator Arp2/3. These findings provide solid evidence that the Arp2/3-dependent cortical actin cytoskeleton plays a pivotal role in the dynamic organisation of the plasma membrane, potentially regulating fundamental cellular processes.
Collapse
Affiliation(s)
- Débora M Andrade
- 1] Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany [2] Centre for Neural Circuits and Behaviour, University of Oxford, Mansfield Road, Oxford OX1 3SR, UK
| | - Mathias P Clausen
- 1] Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany [2] MRC Human Immunology Unit and Wolfson Imaging Centre Oxford, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, UK [3] MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, Odense M,DK-5230, Denmark
| | - Jan Keller
- Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany
| | - Veronika Mueller
- Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany
| | - Congying Wu
- Department of Cell &Developmental Biology, and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill NC 27599, USA
| | - James E Bear
- 1] Department of Cell &Developmental Biology, and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill NC 27599, USA [2] Howard Hughes Medical Institute, University of North Carolina, Chapel Hill NC 27599, USA
| | - Stefan W Hell
- Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany
| | - B Christoffer Lagerholm
- 1] MRC Human Immunology Unit and Wolfson Imaging Centre Oxford, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, UK [2] MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, Odense M,DK-5230, Denmark
| | - Christian Eggeling
- 1] Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany [2] MRC Human Immunology Unit and Wolfson Imaging Centre Oxford, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, UK
| |
Collapse
|
25
|
Wang X, Hou Y, Deng K, Zhang Y, Wang DC, Ding J. Structural Insights into the Molecular Recognition between Cerebral Cavernous Malformation 2 and Mitogen-Activated Protein Kinase Kinase Kinase 3. Structure 2015; 23:1087-96. [PMID: 25982527 DOI: 10.1016/j.str.2015.04.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 03/16/2015] [Accepted: 04/02/2015] [Indexed: 11/18/2022]
Abstract
Cerebral cavernous malformation 2 (CCM2) functions as an adaptor protein implicated in various biological processes. By interacting with the mitogen-activated protein kinase MEKK3, CCM2 either mediates the activation of MEKK3 signaling in response to osmotic stress or negatively regulates MEKK3 signaling, which is important for normal cardiovascular development. However, the molecular basis governing CCM2-MEKK3 interaction is largely unknown. Here we report the crystal structure of the CCM2 C-terminal part (CCM2ct) containing both the five-helix domain (CCM2cts) and the following C-terminal tail. The end of the C-terminal tail forms an isolated helix, which interacts intramolecularly with CCM2cts. By biochemical studies we identified the N-terminal amphiphilic helix of MEKK3 (MEKK3-nhelix) as the essential structural element for CCM2ct binding. We further determined the crystal structure of CCM2cts-MEKK3-nhelix complex, in which MEKK3-nhelix binds to the same site of CCM2cts for CCM2ct intramolecular interaction. These findings build a structural framework for understanding CCM2ct-MEKK3 molecular recognition.
Collapse
Affiliation(s)
- Xiaoyan Wang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China; Department of Clinical Oncology, Taihe Hospital, Hubei University of Medicine, Hubei 442000, People's Republic of China
| | - Yanjie Hou
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Kai Deng
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China; Reproductive Medicine Center, Renmin Hospital, Hubei University of Medicine, Hubei 442000, People's Republic of China
| | - Ying Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Da-Cheng Wang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
| | - Jingjin Ding
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
| |
Collapse
|
26
|
Skau CT, Plotnikov SV, Doyle AD, Waterman CM. Inverted formin 2 in focal adhesions promotes dorsal stress fiber and fibrillar adhesion formation to drive extracellular matrix assembly. Proc Natl Acad Sci U S A 2015; 112:E2447-56. [PMID: 25918420 PMCID: PMC4434736 DOI: 10.1073/pnas.1505035112] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Actin filaments and integrin-based focal adhesions (FAs) form integrated systems that mediate dynamic cell interactions with their environment or other cells during migration, the immune response, and tissue morphogenesis. How adhesion-associated actin structures obtain their functional specificity is unclear. Here we show that the formin-family actin nucleator, inverted formin 2 (INF2), localizes specifically to FAs and dorsal stress fibers (SFs) in fibroblasts. High-resolution fluorescence microscopy and manipulation of INF2 levels in cells indicate that INF2 plays a critical role at the SF-FA junction by promoting actin polymerization via free barbed end generation and centripetal elongation of an FA-associated actin bundle to form dorsal SF. INF2 assembles into FAs during maturation rather than during their initial generation, and once there, acts to promote rapid FA elongation and maturation into tensin-containing fibrillar FAs in the cell center. We show that INF2 is required for fibroblasts to organize fibronectin into matrix fibers and ultimately 3D matrices. Collectively our results indicate an important role for the formin INF2 in specifying the function of fibrillar FAs through its ability to generate dorsal SFs. Thus, dorsal SFs and fibrillar FAs form a specific class of integrated adhesion-associated actin structure in fibroblasts that mediates generation and remodeling of ECM.
Collapse
Affiliation(s)
- Colleen T Skau
- Cell Biology and Physiology Center, National Heart Lung and Blood Institute, and
| | - Sergey V Plotnikov
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada M5S 3G5
| | - Andrew D Doyle
- Cell Biology Section, Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD 20892; and
| | - Clare M Waterman
- Cell Biology and Physiology Center, National Heart Lung and Blood Institute, and
| |
Collapse
|
27
|
Suraneni P, Fogelson B, Rubinstein B, Noguera P, Volkmann N, Hanein D, Mogilner A, Li R. A mechanism of leading-edge protrusion in the absence of Arp2/3 complex. Mol Biol Cell 2015; 26:901-12. [PMID: 25568333 PMCID: PMC4342026 DOI: 10.1091/mbc.e14-07-1250] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Cells employ protrusive leading edges to navigate and promote their migration in diverse physiological environments. Classical models of leading-edge protrusion rely on a treadmilling dendritic actin network that undergoes continuous assembly nucleated by the Arp2/3 complex, forming ruffling lamellipodia. Recent work demonstrated, however, that, in the absence of the Arp2/3 complex, fibroblast cells adopt a leading edge with filopodia-like protrusions (FLPs) and maintain an ability to move, albeit with altered responses to different environmental signals. We show that formin-family actin nucleators are required for the extension of FLPs but are insufficient to produce a continuous leading edge in fibroblasts lacking Arp2/3 complex. Myosin II is concentrated in arc-like regions of the leading edge in between FLPs, and its activity is required for coordinated advancement of these regions with formin-generated FLPs. We propose that actomyosin contraction acting against membrane tension advances the web of arcs between FLPs. Predictions of this model are verified experimentally. The dependence of myosin II in leading-edge advancement helps explain the previously reported defect in directional movement in the Arpc3-null fibroblasts. We provide further evidence that this defect is cell autonomous during chemotaxis.
Collapse
Affiliation(s)
| | - Ben Fogelson
- Courant Institute and Department of Biology, New York University, New York, NY 10012
| | | | | | - Niels Volkmann
- Bioinformatics and Systems Biology Program, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037
| | - Dorit Hanein
- Bioinformatics and Systems Biology Program, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037
| | - Alex Mogilner
- Courant Institute and Department of Biology, New York University, New York, NY 10012
| | - Rong Li
- Stowers Institute for Medical Research, Kansas City, MO 64110 Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160
| |
Collapse
|
28
|
Rotty JD, Wu C, Haynes EM, Suarez C, Winkelman JD, Johnson HE, Haugh JM, Kovar DR, Bear JE. Profilin-1 serves as a gatekeeper for actin assembly by Arp2/3-dependent and -independent pathways. Dev Cell 2014; 32:54-67. [PMID: 25543281 DOI: 10.1016/j.devcel.2014.10.026] [Citation(s) in RCA: 202] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 09/12/2014] [Accepted: 10/30/2014] [Indexed: 12/31/2022]
Abstract
Cells contain multiple F-actin assembly pathways, including the Arp2/3 complex, formins, and Ena/VASP, which have largely been analyzed separately. They collectively generate the bulk of F-actin from a common pool of G-actin; however, the interplay and/or competition between these pathways remains poorly understood. Using fibroblast lines derived from an Arpc2 conditional knockout mouse, we established matched-pair cells with and without the Arp2/3 complex. Arpc2(-/-) cells lack lamellipodia and migrate more slowly than WT cells but have F-actin levels indistinguishable from controls. Actin assembly in Arpc2(-/-) cells was resistant to cytochalasin-D and was highly dependent on profilin-1 and Ena/VASP but not formins. Profilin-1 depletion in WT cells increased F-actin and Arp2/3 complex in lamellipodia. Conversely, addition of exogenous profilin-1 inhibited Arp2/3 complex actin nucleation in vitro and in vivo. Antagonism of the Arp2/3 complex by profilin-1 in cells appears to maintain actin homeostasis by balancing Arp2/3 complex-dependent and -independent actin assembly pathways.
Collapse
Affiliation(s)
- Jeremy D Rotty
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Congying Wu
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Elizabeth M Haynes
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Cristian Suarez
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Jonathan D Winkelman
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Heath E Johnson
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Jason M Haugh
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - David R Kovar
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637, USA; Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
| | - James E Bear
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| |
Collapse
|
29
|
Mesenchymal chemotaxis requires selective inactivation of myosin II at the leading edge via a noncanonical PLCγ/PKCα pathway. Dev Cell 2014; 31:747-60. [PMID: 25482883 DOI: 10.1016/j.devcel.2014.10.024] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 07/25/2014] [Accepted: 10/29/2014] [Indexed: 11/23/2022]
Abstract
Chemotaxis, migration toward soluble chemical cues, is critical for processes such as wound healing and immune surveillance and is exhibited by various cell types, from rapidly migrating leukocytes to slow-moving mesenchymal cells. To study mesenchymal chemotaxis, we observed cell migration in microfluidic chambers that generate stable gradients of platelet-derived growth factor (PDGF). Surprisingly, we found that pathways implicated in amoeboid chemotaxis, such as PI3K and mammalian target of rapamycin signaling, are dispensable for PDGF chemotaxis. Instead, we find that local inactivation of Myosin IIA, through a noncanonical Ser1/2 phosphorylation of the regulatory light chain, is essential. This site is phosphorylated by PKCα, which is activated by an intracellular gradient of diacylglycerol generated by PLCγ. Using a combination of live imaging and gradients of activators/inhibitors in the microfluidic chambers, we demonstrate that this signaling pathway and subsequent inhibition of Myosin II activity at the leading edge are required for mesenchymal chemotaxis.
Collapse
|
30
|
Steering cell migration: lamellipodium dynamics and the regulation of directional persistence. Nat Rev Mol Cell Biol 2014; 15:577-90. [PMID: 25145849 DOI: 10.1038/nrm3861] [Citation(s) in RCA: 394] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Membrane protrusions at the leading edge of cells, known as lamellipodia, drive cell migration in many normal and pathological situations. Lamellipodial protrusion is powered by actin polymerization, which is mediated by the actin-related protein 2/3 (ARP2/3)-induced nucleation of branched actin networks and the elongation of actin filaments. Recently, advances have been made in our understanding of positive and negative ARP2/3 regulators (such as the SCAR/WAVE (SCAR/WASP family verprolin-homologous protein) complex and Arpin, respectively) and of proteins that control actin branch stability (such as glial maturation factor (GMF)) or actin filament elongation (such as ENA/VASP proteins) in lamellipodium dynamics and cell migration. This Review highlights how the balance between actin filament branching and elongation, and between the positive and negative feedback loops that regulate these activities, determines lamellipodial persistence. Importantly, directional persistence, which results from lamellipodial persistence, emerges as a critical factor in steering cell migration.
Collapse
|
31
|
Abstract
An exciting frontier in biology is understanding the functions of basic cell biological machinery in complex tissues. This approach is expected to uncover novel modes of regulation as well as reveal how core machinery is repurposed by different tissues to accomplish different physiological outputs. F-actin plays roles in cell shape, adhesion, migration and signaling – diverse functions that require a specific organization established by a myriad of regulators. Here, we discuss the role of the actin nucleating Arp2/3 complex and the unexpected roles that it plays in a stratified epithelial tissue, the epidermis. While many expected phenotypes such as defects in architecture and cell adhesion were lacking, loss of the Arp2/3 complex activity resulted in epidermal barrier and differentiation defects. This teaches us that, while informative, cell culture approaches are limiting and that studies of the Arp2/3 complex in diverse tissues are expected to yield many more surprises.
Collapse
Affiliation(s)
- Terry Lechler
- Departments of Dermatology and Cell Biology, Duke University ; Durham, NC USA
| |
Collapse
|
32
|
Directed migration of mesenchymal cells: where signaling and the cytoskeleton meet. Curr Opin Cell Biol 2014; 30:74-82. [PMID: 24999834 DOI: 10.1016/j.ceb.2014.06.005] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 06/13/2014] [Accepted: 06/15/2014] [Indexed: 02/04/2023]
Abstract
Cell migration directed by spatial cues, or taxis, is a primary mechanism for orchestrating concerted and collective cell movements during development, wound repair, and immune responses. Compared with the classic example of amoeboid chemotaxis, in which fast-moving cells such as neutrophils are directed by gradients of soluble factors, directed migration of slow-moving mesenchymal cells such as fibroblasts is poorly understood. Mesenchymal cells possess a distinctive organization of the actin cytoskeleton and associated adhesion complexes as its primary mechanical system, generating the asymmetric forces required for locomotion without strong polarization. The emerging hypothesis is that the molecular underpinnings of mesenchymal taxis involve distinct signaling pathways and diverse requirements for regulation.
Collapse
|
33
|
Beckham Y, Vasquez RJ, Stricker J, Sayegh K, Campillo C, Gardel ML. Arp2/3 inhibition induces amoeboid-like protrusions in MCF10A epithelial cells by reduced cytoskeletal-membrane coupling and focal adhesion assembly. PLoS One 2014; 9:e100943. [PMID: 24967897 PMCID: PMC4072770 DOI: 10.1371/journal.pone.0100943] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 06/02/2014] [Indexed: 11/18/2022] Open
Abstract
Here we demonstrate that Arp2/3 regulates a transition between mesenchymal and amoeboid protrusions in MCF10A epithelial cells. Using genetic and pharmacological means, we first show Arp2/3 inhibition impairs directed cell migration. Arp2/3 inhibition results in a dramatically impaired cell adhesion, causing deficient cell attachment and spreading to ECM as well as an 8-fold decrease in nascent adhesion assembly at the leading edge. While Arp2/3 does not play a significant role in myosin-dependent adhesion growth, mature focal adhesions undergo large scale movements against the ECM suggesting reduced coupling to the ECM. Cell edge protrusions occur at similar rates when Arp2/3 is inhibited but their morphology is dramatically altered. Persistent lamellipodia are abrogated and we observe a markedly increased incidence of blebbing and unstable pseuodopods. Micropipette-aspiration assays indicate that Arp2/3-inhibited cells have a weak coupling between the cell cortex and the plasma membrane, and suggest a potential mechanism for increased pseudopod and bleb formation. Pseudopods are not sensitive to reduced in formin or myosin II activity. Collectively, these results indicate that Arp2/3 is not necessary for rapid protrusion of the cell edge but plays a crucial role in assembling focal adhesions required for its stabilization.
Collapse
Affiliation(s)
- Yvonne Beckham
- Institute for Biophysical Dynamics, University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Robert J. Vasquez
- Section of Hematology, Oncology and Stem Cell Transplantation, Department of Pediatrics, University of Chicago Medical Center, Chicago, Illinois, United States of America
| | - Jonathan Stricker
- James Franck Institute, University of Chicago, Chicago, Illinois, United States of America
- Department of Physics, University of Chicago, Chicago, Illinois, United States of America
| | - Kareem Sayegh
- James Franck Institute, University of Chicago, Chicago, Illinois, United States of America
- Department of Physics, University of Chicago, Chicago, Illinois, United States of America
| | - Clement Campillo
- Laboratoire Physico-Chimie, Institut Curie, Centre de Recherche, Paris, France
- Laboratoire Analyse et Modélisation pour la Biologie et l’ Environnement, Université d’Evry Val d’Essonne, Evry, France
| | - Margaret L. Gardel
- Institute for Biophysical Dynamics, University of Chicago Medical Center, Chicago, Illinois, United States of America
- James Franck Institute, University of Chicago, Chicago, Illinois, United States of America
- Department of Physics, University of Chicago, Chicago, Illinois, United States of America
- * E-mail:
| |
Collapse
|
34
|
Short B. Arp2/3-deficient cells share their problems. J Cell Biol 2013. [PMCID: PMC3871441 DOI: 10.1083/jcb.2036if] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Loss of the actin-nucleating complex activates a stress response that nonautonomously inhibits chemotaxis.
Collapse
|