1
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Hayes JB, Bainbridge AM, Burnette DT. Alpha-actinin-1 stabilizes focal adhesions to facilitate sarcomere assembly in cardiac myocytes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.03.28.645933. [PMID: 40196508 PMCID: PMC11974845 DOI: 10.1101/2025.03.28.645933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 04/09/2025]
Abstract
Cardiac sarcomere assembly is a highly orchestrated process requiring integration between intracellular contractile components and extracellular adhesions. While α-actinin-2 (ACTN2) is well known for its structural role at Z-discs, the function of the "non-muscle" paralog α-actinin-1 (ACTN1) in cardiomyocytes remains unclear. Using human induced pluripotent stem cell-derived cardiac myocytes (hiCMs), we demonstrate that ACTN1 is essential for sarcomere assembly. siRNA-mediated depletion of ACTN1 disrupted Z-line formation and impaired sarcomere organization, defects that were rescued by exogenous ACTN1 but not ACTN2, revealing non-redundant functions. Unlike ACTN2, ACTN1 localized predominantly to focal adhesions and was required for adhesion maturation, as evidenced by reduced adhesion size and number following ACTN1 depletion. Live-cell imaging of vinculin dynamics showed decreased stability of adhesion-associated vinculin in ACTN1-deficient cells, whereas paxillin dynamics were unaffected. These results suggest that ACTN1 stabilizes focal adhesions to promote effective force transmission during sarcomere assembly.
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Affiliation(s)
- James B Hayes
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, USA
| | - Anna M Bainbridge
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, USA
- University of Tennessee, Knoxville, TN, USA
| | - Dylan T Burnette
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, USA
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2
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Morishita H, Kawai K, Egami Y, Honda K, Araki N. Live-cell imaging and CLEM reveal the existence of ACTN4-dependent ruffle-edge lamellipodia acting as a novel mode of cell migration. Exp Cell Res 2024; 442:114232. [PMID: 39222868 DOI: 10.1016/j.yexcr.2024.114232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 08/26/2024] [Accepted: 08/29/2024] [Indexed: 09/04/2024]
Abstract
α-Actinin-4 (ACTN4) expression levels are correlated with the invasive and metastatic potential of cancer cells; however, the underlying mechanism remains unclear. Here, we identified ACTN4-localized ruffle-edge lamellipodia using live-cell imaging and correlative light and electron microscopy (CLEM). BSC-1 cells expressing EGFP-ACTN4 showed that ACTN4 was most abundant in the leading edges of lamellipodia, although it was also present in stress fibers and focal adhesions. ACTN4 localization in lamellipodia was markedly diminished by phosphoinositide 3-kinase inhibition, whereas its localization in stress fibers and focal adhesions remained. Furthermore, overexpression of ACTN4, but not ACTN1, promoted lamellipodial formation. Live-cell analysis demonstrated that ACTN4-enriched lamellipodia are highly dynamic and associated with cell migration. CLEM revealed that ACTN4-enriched lamellipodia exhibit a characteristic morphology of multilayered ruffle-edges that differs from canonical flat lamellipodia. Similar ruffle-edge lamellipodia were observed in A549 and MDA-MB-231 invasive cancer cells. ACTN4 knockdown suppressed the formation of ruffle-edge lamellipodia and cell migration during wound healing in A549 monolayer cultures. Additionally, membrane-type 1 matrix metalloproteinase was observed in the membrane ruffles, suggesting that ruffle-edge lamellipodia have the ability to degrade the extracellular matrix and may contribute to active cell migration/invasion in certain cancer cell types.
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Affiliation(s)
- Haruka Morishita
- Department of Histology and Cell Biology, School of Medicine, Kagawa University, Kagawa, 761-0793, Miki, Japan
| | - Katsuhisa Kawai
- Department of Histology and Cell Biology, School of Medicine, Kagawa University, Kagawa, 761-0793, Miki, Japan
| | - Youhei Egami
- Department of Histology and Cell Biology, School of Medicine, Kagawa University, Kagawa, 761-0793, Miki, Japan
| | - Kazufumi Honda
- Department of Bioregulation, Graduate of Medicine, Nippon Medical School, Sendagi, Bunkyo-ku, 113-8602, Tokyo, Japan
| | - Nobukazu Araki
- Department of Histology and Cell Biology, School of Medicine, Kagawa University, Kagawa, 761-0793, Miki, Japan.
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3
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Jakob R, Britt BR, Giampietro C, Mazza E, Ehret AE. Discrete network models of endothelial cells and their interactions with the substrate. Biomech Model Mechanobiol 2024; 23:941-957. [PMID: 38351427 PMCID: PMC11101350 DOI: 10.1007/s10237-023-01815-1] [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: 09/04/2023] [Accepted: 12/30/2023] [Indexed: 05/18/2024]
Abstract
Endothelial cell monolayers line the inner surfaces of blood and lymphatic vessels. They are continuously exposed to different mechanical loads, which may trigger mechanobiological signals and hence play a role in both physiological and pathological processes. Computer-based mechanical models of cells contribute to a better understanding of the relation between cell-scale loads and cues and the mechanical state of the hosting tissue. However, the confluency of the endothelial monolayer complicates these approaches since the intercellular cross-talk needs to be accounted for in addition to the cytoskeletal mechanics of the individual cells themselves. As a consequence, the computational approach must be able to efficiently model a large number of cells and their interaction. Here, we simulate cytoskeletal mechanics by means of molecular dynamics software, generally suitable to deal with large, locally interacting systems. Methods were developed to generate models of single cells and large monolayers with hundreds of cells. The single-cell model was considered for a comparison with experimental data. To this end, we simulated cell interactions with a continuous, deformable substrate, and computationally replicated multistep traction force microscopy experiments on endothelial cells. The results indicate that cell discrete network models are able to capture relevant features of the mechanical behaviour and are thus well-suited to investigate the mechanics of the large cytoskeletal network of individual cells and cell monolayers.
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Affiliation(s)
- Raphael Jakob
- Institute for Mechanical Systems, ETH Zurich, CH-8092, Zürich, Switzerland
| | - Ben R Britt
- Institute for Mechanical Systems, ETH Zurich, CH-8092, Zürich, Switzerland
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600, Dübendorf, Switzerland
| | - Costanza Giampietro
- Institute for Mechanical Systems, ETH Zurich, CH-8092, Zürich, Switzerland
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600, Dübendorf, Switzerland
| | - Edoardo Mazza
- Institute for Mechanical Systems, ETH Zurich, CH-8092, Zürich, Switzerland
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600, Dübendorf, Switzerland
| | - Alexander E Ehret
- Institute for Mechanical Systems, ETH Zurich, CH-8092, Zürich, Switzerland.
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600, Dübendorf, Switzerland.
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4
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Mukherjee D, Previs RA, Haines C, Al Abo M, Juras PK, Strickland KC, Chakraborty B, Artham S, Whitaker RS, Hebert K, Fontenot J, Patierno SR, Freedman JA, Lau FH, Burow ME, Chang CY, McDonnell DP. Targeting CaMKK2 Inhibits Actin Cytoskeletal Assembly to Suppress Cancer Metastasis. Cancer Res 2023; 83:2889-2907. [PMID: 37335130 PMCID: PMC10472110 DOI: 10.1158/0008-5472.can-22-1622] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 01/05/2023] [Accepted: 06/13/2023] [Indexed: 06/21/2023]
Abstract
Triple-negative breast cancers (TNBC) tend to become invasive and metastatic at early stages in their development. Despite some treatment successes in early-stage localized TNBC, the rate of distant recurrence remains high, and long-term survival outcomes remain poor. In a search for new therapeutic targets for this disease, we observed that elevated expression of the serine/threonine kinase calcium/calmodulin (CaM)-dependent protein kinase kinase 2 (CaMKK2) is highly correlated with tumor invasiveness. In validation studies, genetic disruption of CaMKK2 expression or inhibition of its activity with small molecule inhibitors disrupted spontaneous metastatic outgrowth from primary tumors in murine xenograft models of TNBC. High-grade serous ovarian cancer (HGSOC), a high-risk, poor prognosis ovarian cancer subtype, shares many features with TNBC, and CaMKK2 inhibition effectively blocked metastatic progression in a validated xenograft model of this disease. Mechanistically, CaMKK2 increased the expression of the phosphodiesterase PDE1A, which hydrolyzed cyclic guanosine monophosphate (cGMP) to decrease the cGMP-dependent activity of protein kinase G1 (PKG1). Inhibition of PKG1 resulted in decreased phosphorylation of vasodilator-stimulated phosphoprotein (VASP), which in its hypophosphorylated state binds to and regulates F-actin assembly to facilitate cell movement. Together, these findings establish a targetable CaMKK2-PDE1A-PKG1-VASP signaling pathway that controls cancer cell motility and metastasis by impacting the actin cytoskeleton. Furthermore, it identifies CaMKK2 as a potential therapeutic target that can be exploited to restrict tumor invasiveness in patients diagnosed with early-stage TNBC or localized HGSOC. SIGNIFICANCE CaMKK2 regulates actin cytoskeletal dynamics to promote tumor invasiveness and can be inhibited to suppress metastasis of breast and ovarian cancer, indicating CaMKK2 inhibition as a therapeutic strategy to arrest disease progression.
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Affiliation(s)
- Debarati Mukherjee
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina
| | - Rebecca A. Previs
- Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, Duke University Medical Center, Durham, North Carolina
| | - Corinne Haines
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina
| | - Muthana Al Abo
- Department of Medicine, Division of Medical Oncology, Duke University School of Medicine, Durham, North Carolina
| | - Patrick K. Juras
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina
| | - Kyle C. Strickland
- Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - Binita Chakraborty
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina
| | - Sandeep Artham
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina
| | - Regina S. Whitaker
- Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, Duke University Medical Center, Durham, North Carolina
| | - Katherine Hebert
- Department of Medicine, Section of Hematology and Oncology, Tulane University School of Medicine, New Orleans, Louisiana
| | - Jake Fontenot
- Department of Surgery, Section of Plastic & Reconstructive Surgery, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | - Steven R. Patierno
- Department of Medicine, Division of Medical Oncology, Duke University School of Medicine, Durham, North Carolina
| | - Jennifer A. Freedman
- Department of Medicine, Division of Medical Oncology, Duke University School of Medicine, Durham, North Carolina
| | - Frank H. Lau
- Department of Surgery, Section of Plastic & Reconstructive Surgery, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | - Matthew E. Burow
- Department of Medicine, Section of Hematology and Oncology, Tulane University School of Medicine, New Orleans, Louisiana
| | - Ching-Yi Chang
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina
| | - Donald P. McDonnell
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina
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5
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Zhang H, Fan J, Maclin JM, Wan LQ. The Actin Crosslinker Fascin Regulates Cell Chirality. Adv Biol (Weinh) 2023; 7:e2200240. [PMID: 36658789 PMCID: PMC10293081 DOI: 10.1002/adbi.202200240] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 12/27/2022] [Indexed: 01/21/2023]
Abstract
The left-right (L-R) asymmetry of the cells, or cell chirality, is a well-known intrinsic property derived from the dynamic organization of the actin cytoskeleton. Cell chirality can be regulated by actin-binding proteins such as α-actinin-1 and can also be mediated by certain signaling pathways, such as protein kinase C (PKC) signaling. Fascin, an actin crosslinker known to mediate parallel bundling of actin filaments, appears as a prominent candidate in cell chirality regulation, given its role in facilitating cell migration as an important PKC substrate. Here, it is shown that the chirality of NIH/3T3 cells can be altered by PKC activation and fascin manipulation. With either small-molecule drug inhibition or genetic knockdown of fascin, the chirality of 3T3 cells is reversed from a clockwise (CW) bias to a counterclockwise (CCW) bias on ring-shaped micropatterns, accompanied by the reversal in cell directional migration. The Ser-39 fascin-actin binding sites are further explored in cell chirality regulation. The findings of this study reveal the critical role of fascin as an important intermediator in cell chirality, shedding novel insights into the mechanisms of L-R asymmetric cell migration and multicellular morphogenesis.
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Affiliation(s)
- Haokang Zhang
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Jie Fan
- Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI 48128, USA
| | - Joshua M.A. Maclin
- Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
- Department of Biological Science, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Leo Q. Wan
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
- Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
- Department of Biological Science, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
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6
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Mukherjee D, Previs RA, Haines CN, Abo MA, Juras PK, Strickland KC, Chakraborty B, Artham S, Whitaker R, Hebert KL, Fontenot J, Patierno SR, Freedman JA, Lau FH, Burow M, Chang CY, McDonnell DP. Ca 2+ /Calmodulin Dependent Protein Kinase Kinase-2 (CaMKK2) promotes Protein Kinase G (PKG)-dependent actin cytoskeletal assembly to increase tumor metastasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.17.536051. [PMID: 37131673 PMCID: PMC10153149 DOI: 10.1101/2023.04.17.536051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Triple-negative breast cancers (TNBCs) tend to become highly invasive early during cancer development. Despite some successes in the initial treatment of patients diagnosed with early-stage localized TNBC, the rate of metastatic recurrence remains high with poor long-term survival outcomes. Here we show that elevated expression of the serine/threonine-kinase, Calcium/Calmodulin (CaM)-dependent protein kinase kinase-2 (CaMKK2), is highly correlated with tumor invasiveness. We determined that genetic disruption of CaMKK2 expression, or inhibition of its activity, disrupted spontaneous metastatic outgrowth from primary tumors in murine xenograft models of TNBC. High-grade serous ovarian cancer (HGSOC), a high-risk, poor-prognosis ovarian cancer subtype, shares many genetic features with TNBC, and importantly, CaMKK2 inhibition effectively blocked metastatic progression in a validated xenograft model of this disease. Probing the mechanistic links between CaMKK2 and metastasis we defined the elements of a new signaling pathway that impacts actin cytoskeletal dynamics in a manner which increases cell migration/invasion and metastasis. Notably, CaMKK2 increases the expression of the phosphodiesterase PDE1A which decreases the cGMP-dependent activity of protein kinase G1 (PKG1). This inhibition of PKG1 results in decreased phosphorylation of Vasodilator-Stimulated Phosphoprotein (VASP), which in its hypophosphorylated state binds to and regulates F-actin assembly to facilitate contraction/cell movement. Together, these data establish a targetable CaMKK2-PDE1A-PKG1-VASP signaling pathway that controls cancer cell motility and metastasis. Further, it credentials CaMKK2 as a therapeutic target that can be exploited in the discovery of agents for use in the neoadjuvant/adjuvant setting to restrict tumor invasiveness in patients diagnosed with early-stage TNBC or localized HGSOC.
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7
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Rajan S, Kudryashov DS, Reisler E. Actin Bundles Dynamics and Architecture. Biomolecules 2023; 13:450. [PMID: 36979385 PMCID: PMC10046292 DOI: 10.3390/biom13030450] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 03/04/2023] Open
Abstract
Cells use the actin cytoskeleton for many of their functions, including their division, adhesion, mechanosensing, endo- and phagocytosis, migration, and invasion. Actin bundles are the main constituent of actin-rich structures involved in these processes. An ever-increasing number of proteins that crosslink actin into bundles or regulate their morphology is being identified in cells. With recent advances in high-resolution microscopy and imaging techniques, the complex process of bundles formation and the multiple forms of physiological bundles are beginning to be better understood. Here, we review the physiochemical and biological properties of four families of highly conserved and abundant actin-bundling proteins, namely, α-actinin, fimbrin/plastin, fascin, and espin. We describe the similarities and differences between these proteins, their role in the formation of physiological actin bundles, and their properties-both related and unrelated to their bundling abilities. We also review some aspects of the general mechanism of actin bundles formation, which are known from the available information on the activity of the key actin partners involved in this process.
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Affiliation(s)
- Sudeepa Rajan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Dmitri S. Kudryashov
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH 43210, USA
| | - Emil Reisler
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
- Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
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8
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Gharaba S, Paz O, Feld L, Abashidze A, Weinrab M, Muchtar N, Baransi A, Shalem A, Sprecher U, Wolf L, Wolfenson H, Weil M. Perturbed actin cap as a new personalized biomarker in primary fibroblasts of Huntington's disease patients. Front Cell Dev Biol 2023; 11:1013721. [PMID: 36743412 PMCID: PMC9889876 DOI: 10.3389/fcell.2023.1013721] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 01/03/2023] [Indexed: 01/19/2023] Open
Abstract
Primary fibroblasts from patient's skin biopsies are directly isolated without any alteration in the genome, retaining in culture conditions their endogenous cellular characteristics and biochemical properties. The aim of this study was to identify a distinctive cell phenotype for potential drug evaluation in fibroblasts from Huntington's Disease (HD) patients, using image-based high content analysis. We show that HD fibroblasts have a distinctive nuclear morphology associated with a nuclear actin cap deficiency. This in turn affects cell motility in a similar manner to fibroblasts from Hutchinson-Gilford progeria syndrome (HGPS) patients used as known actin cap deficient cells. Moreover, treatment of the HD cells with either Latrunculin B, used to disrupt actin cap formation, or the antioxidant agent Mitoquinone, used to improve mitochondrial activity, show expected opposite effects on actin cap associated morphological features and cell motility. Deep data analysis allows strong cluster classification within HD cells according to patients' disease severity score which is distinct from HGPS and matching controls supporting that actin cap is a biomarker in HD patients' cells correlated with HD severity status that could be modulated by pharmacological agents as tool for personalized drug evaluation.
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Affiliation(s)
- Saja Gharaba
- Laboratory for Personalized Medicine and Neurodegenerative Diseases, The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty for Life Sciences, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Omri Paz
- Laboratory for Personalized Medicine and Neurodegenerative Diseases, The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty for Life Sciences, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Lea Feld
- Department of Genetics and Developmental Biology, The Rappaport Faculty of Medicine and Research Institute, Technion—Israel Institute of Technology, Haifa, Israel
| | - Anastasia Abashidze
- The Blavatnik Center for Drug Discovery, Tel Aviv University, Tel Aviv, Israel
| | - Maydan Weinrab
- Laboratory for Personalized Medicine and Neurodegenerative Diseases, The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty for Life Sciences, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Noam Muchtar
- Laboratory for Personalized Medicine and Neurodegenerative Diseases, The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty for Life Sciences, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Adam Baransi
- Laboratory for Personalized Medicine and Neurodegenerative Diseases, The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty for Life Sciences, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Aviv Shalem
- Laboratory for Personalized Medicine and Neurodegenerative Diseases, The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty for Life Sciences, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
- The Blavatnik School of Computer Sciences, Tel Aviv University, Tel Aviv, Israel
- School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Uri Sprecher
- Laboratory for Personalized Medicine and Neurodegenerative Diseases, The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty for Life Sciences, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Lior Wolf
- The Blavatnik School of Computer Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Haguy Wolfenson
- Department of Genetics and Developmental Biology, The Rappaport Faculty of Medicine and Research Institute, Technion—Israel Institute of Technology, Haifa, Israel
| | - Miguel Weil
- Laboratory for Personalized Medicine and Neurodegenerative Diseases, The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty for Life Sciences, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
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9
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Fatima M, Sheikh A, Abourehab MAS, Kesharwani P. Advancements in Polymeric Nanocarriers to Mediate Targeted Therapy against Triple-Negative Breast Cancer. Pharmaceutics 2022; 14:2432. [PMID: 36365249 PMCID: PMC9695386 DOI: 10.3390/pharmaceutics14112432] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/06/2022] [Accepted: 11/08/2022] [Indexed: 11/12/2022] Open
Abstract
Triple-negative breast cancer (TNBC) is a destructive disease with a poor prognosis, low survival rate and high rate of metastasis. It comprises 15% of total breast cancers and is marked by deficiency of three important receptor expressions, i.e., progesterone, estrogen, and human epidermal growth factor receptors. This absence of receptors is the foremost cause of current TNBC therapy failure, resulting in poor therapeutic response in patients. Polymeric nanoparticles are gaining much popularity for transporting chemotherapeutics, genes, and small-interfering RNAs. Due to their exclusive properties such as great stability, easy surface modification, stimuli-responsive and controlled drug release, ability to condense more than one therapeutic moiety inside, tumor-specific delivery of payload, enhanced permeation and retention effect, present them as ideal nanocarriers for increasing efficacy, bioavailability and reducing the toxicity of therapeutic agents. They can even be used as theragnostic agents for the diagnosis of TNBC along with its treatment. In this review, we discuss the limitations of already existing TNBC therapies and highlight the novel approach to designing and the functionalization of polymeric nanocarriers for the effective treatment of TNBC.
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Affiliation(s)
- Mahak Fatima
- Department of Pharmaceutics, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Afsana Sheikh
- Department of Pharmaceutics, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Mohammed A. S. Abourehab
- Department of Pharmaceutics, College of Pharmacy, Umm Al-Qura University, Makkah 21955, Saudi Arabia
| | - Prashant Kesharwani
- Department of Pharmaceutics, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
- Center for Transdisciplinary Research, Department of Pharmacology, Saveetha Dental College, Saveetha Institute of Medical and Technical Science, Chennai 602105, India
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10
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Chinchole A, Lone KA, Tyagi S. MLL regulates the actin cytoskeleton and cell migration by stabilising Rho GTPases via the expression of RhoGDI1. J Cell Sci 2022; 135:jcs260042. [PMID: 36111497 PMCID: PMC7615853 DOI: 10.1242/jcs.260042] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 09/09/2022] [Indexed: 04/26/2024] Open
Abstract
Attainment of proper cell shape and the regulation of cell migration are essential processes in the development of an organism. The mixed lineage leukemia (MLL or KMT2A) protein, a histone 3 lysine 4 (H3K4) methyltransferase, plays a critical role in cell-fate decisions during skeletal development and haematopoiesis in higher vertebrates. Rho GTPases - RhoA, Rac1 and CDC42 - are small G proteins that regulate various key cellular processes, such as actin cytoskeleton formation, the maintenance of cell shape and cell migration. Here, we report that MLL regulates the homeostasis of these small Rho GTPases. Loss of MLL resulted in an abnormal cell shape and a disrupted actin cytoskeleton, which lead to diminished cell spreading and migration. MLL depletion affected the stability and activity of Rho GTPases in a SET domain-dependent manner, but these Rho GTPases were not direct transcriptional targets of MLL. Instead, MLL regulated the transcript levels of their chaperone protein RhoGDI1 (also known as ARHGDIA). Using MDA-MB-231, a triple-negative breast cancer cell line with high RhoGDI1 expression, we show that MLL depletion or inhibition by small molecules reduces tumour progression in nude mice. Our studies highlight the central regulatory role of MLL in Rho/Rac/CDC42 signalling pathways. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Akash Chinchole
- Laboratory of Cell Cycle Regulation, Centre for DNA Fingerprinting and Diagnostics (CDFD), Uppal, Hyderabad 500039, India
- Graduate Studies, Manipal Academy of Higher Education, Manipal 567104, India
| | - Kaisar Ahmad Lone
- Laboratory of Cell Cycle Regulation, Centre for DNA Fingerprinting and Diagnostics (CDFD), Uppal, Hyderabad 500039, India
- Graduate Studies, Regional Centre for Biotechnology, Faridabad 121001, India
| | - Shweta Tyagi
- Laboratory of Cell Cycle Regulation, Centre for DNA Fingerprinting and Diagnostics (CDFD), Uppal, Hyderabad 500039, India
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11
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Narasimhan S, Holmes WR, Kaverina I. Merging of ventral fibers at adhesions drives the remodeling of cellular contractile systems in fibroblasts. Cytoskeleton (Hoboken) 2022; 79:81-93. [PMID: 35996927 PMCID: PMC9770016 DOI: 10.1002/cm.21722] [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: 04/22/2022] [Revised: 08/10/2022] [Accepted: 08/17/2022] [Indexed: 01/30/2023]
Abstract
Ventral stress fibers (VSFs) are contractile actin fibers dynamically attached to cell-matrix focal adhesions. VSFs are critical in cellular traction force production and migration. VSFs vary from randomly oriented short, thinner fibers to long, thick fibers that span along the whole long axis of a cell. De novo VSF formation was shown to occur by cortical actin mesh condensation or by crosslinking of dorsal stress fibers and transverse arcs at the cell front. However, the formation of long VSFs that extend across the whole cell axis is not well understood. Here, we report a novel phenomenon of VSF merging in migratory fibroblast cells, which is guided by mechanical force balance and contributes to VSF alignment along the long cell axis. The mechanism of VSF merging involves two steps: connection of two ventral fibers by an emerging myosin II bridge at an intervening adhesion and intervening adhesion dissolution. Our data indicate that these two steps are interdependent: slow adhesion disassembly leads to the slowing of the myosin bridge formation. Cellular data and computational modeling show that the contact angle between merging fibers decides successful merging, with shallow angles leading to merge failure. Our data and modeling further show that merging increases the share of uniformly aligned long VSFs, likely contributing to directional traction force production. Thus, we characterize merging as a process for dynamic reorganization of VSFs with functional significance for directional cell migration.
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Affiliation(s)
| | | | - Irina Kaverina
- Department of Cell and Developmental Biology, Vanderbilt University
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12
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Peng JM, Chiu CF, Cheng JH, Liu HY, Chang YL, Luo JW, Weng YT, Luo HL. Evasion of NK cell immune surveillance via the vimentin-mediated cytoskeleton remodeling. Front Immunol 2022; 13:883178. [PMID: 36032170 PMCID: PMC9402923 DOI: 10.3389/fimmu.2022.883178] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 07/22/2022] [Indexed: 12/24/2022] Open
Abstract
Cancer immunotherapy uses the immune system to achieve therapeutic effects; however, its effect is still limited. Therefore, in addition to immune checkpoint-based treatment, the development of other strategies that can inhibit cancer cells from resisting immune cytotoxicity is important. There are currently few studies on the mechanism of tumors using cytoskeletal proteins reorganization to participate in immune escape. In this study, we identified cancer cell lines that were sensitive or resistant to natural killer cells in urothelial and lung cancer using the natural killer cell sensitivity assay. We found that immunoresistant cancer cells avoid natural killer cell-mediated cytotoxicity by upregulation of vimentin and remodeling of actin cytoskeleton. Immunofluorescence staining showed that immune cells promoted the formation of actin filaments at the immune synapse, which was not found in immunosensitive cancer cells. Pretreatment of the actin polymerization inhibitors latrunculin B increased the cytotoxicity of natural killer cells, suggesting that cytoskeleton remodeling plays a role in resisting immune cell attack. In addition, silencing of vimentin with shRNA potentiated the cytotoxicity of natural killer cells. Interestingly, the upregulation and extension of vimentin was found in tumor islands of upper tract urothelial carcinoma infiltrated by natural killer cells. Conversely, tumors without natural killer cell invasion showed less vimentin signal. The expression level of vimentin was highly correlated with natural killer cell infiltration. In summary, we found that when immune cells attack cancer cells, the cancer cells resist immune cytotoxicity through upregulated vimentin and actin reorganization. In addition, this immune resistance mechanism was also found in patient tumors, indicating the possibility that they can be applied to evaluate the immune response in clinical diagnosis.
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Affiliation(s)
- Jei-Ming Peng
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
- *Correspondence: Jei-Ming Peng, ; ; Hao-Lun Luo,
| | - Ching-Feng Chiu
- Graduate Institute of Metabolism and Obesity Sciences, Taipei Medical University, Taipei, Taiwan
| | - Jai-Hong Cheng
- Center for Shockwave Medicine and Tissue Engineering, Medical Research, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
- Department of Leisure and Sports Management, Cheng Shiu University, Kaohsiung, Taiwan
| | - Hui-Ying Liu
- Department of Urology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Yin-Lun Chang
- Department of Urology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Jia-Wun Luo
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Yu-Ting Weng
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Hao-Lun Luo
- Department of Urology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
- *Correspondence: Jei-Ming Peng, ; ; Hao-Lun Luo,
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13
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Che H, Selig M, Rolauffs B. Micro-patterned cell populations as advanced pharmaceutical drugs with precise functional control. Adv Drug Deliv Rev 2022; 184:114169. [PMID: 35217114 DOI: 10.1016/j.addr.2022.114169] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 02/14/2022] [Accepted: 02/15/2022] [Indexed: 11/29/2022]
Abstract
Human cells are both advanced pharmaceutical drugs and 'drug deliverers'. However, functional control prior to or after cell implantation remains challenging. Micro-patterning cells through geometrically defined adhesion sites allows controlling morphogenesis, polarity, cellular mechanics, proliferation, migration, differentiation, stemness, cell-cell interactions, collective cell behavior, and likely immuno-modulatory properties. Consequently, generating micro-patterned therapeutic cells is a promising idea that has not yet been realized and few if any steps have been undertaken in this direction. This review highlights potential therapeutic applications, summarizes comprehensively the many cell functions that have been successfully controlled through micro-patterning, details the established micro-pattern designs, introduces the available fabrication technologies to the non-specialized reader, and suggests a quality evaluation score. Such a broad review is not yet available but would facilitate the manufacturing of therapeutically patterned cell populations using micro-patterned cell-instructive biomaterials for improved functional control as drug delivery systems in the context of cells as pharmaceutical products.
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Affiliation(s)
- Hui Che
- G.E.R.N. Research Center for Tissue Replacement, Regeneration & Neogenesis, Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center-Albert-Ludwigs-University of Freiburg, 79085 Freiburg im Breisgau, Germany; Orthopedics and Sports Medicine Center, Suzhou Municipal Hospital (North District), Nanjing Medical University Affiliated Suzhou Hospital, Suzhou 215006, China
| | - Mischa Selig
- G.E.R.N. Research Center for Tissue Replacement, Regeneration & Neogenesis, Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center-Albert-Ludwigs-University of Freiburg, 79085 Freiburg im Breisgau, Germany; Faculty of Biology, University of Freiburg, Schaenzlestrasse 1, D-79104 Freiburg, Germany
| | - Bernd Rolauffs
- G.E.R.N. Research Center for Tissue Replacement, Regeneration & Neogenesis, Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center-Albert-Ludwigs-University of Freiburg, 79085 Freiburg im Breisgau, Germany.
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14
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Homayoonfal M, Asemi Z, Yousefi B. Targeting microRNAs with thymoquinone: a new approach for cancer therapy. Cell Mol Biol Lett 2021; 26:43. [PMID: 34627167 PMCID: PMC8502376 DOI: 10.1186/s11658-021-00286-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/27/2021] [Indexed: 02/08/2023] Open
Abstract
Cancer is a global disease involving transformation of normal cells into tumor types via numerous mechanisms, with mortality among all generations, in spite of the breakthroughs in chemotherapy, radiotherapy and/or surgery for cancer treatment. Since one in six deaths is due to cancer, it is one of the overriding priorities of world health. Recently, bioactive natural compounds have been widely recognized due to their therapeutic effects for treatment of various chronic disorders, notably cancer. Thymoquinone (TQ), the most valuable constituent of black cumin seeds, has shown anti-cancer characteristics in a wide range of animal models. The revolutionary findings have revealed TQ's ability to regulate microRNA (miRNA) expression, offering a promising approach for cancer therapy. MiRNAs are small noncoding RNAs that modulate gene expression by means of variation in features of mRNA. MiRNAs manage several biological processes including gene expression and cellular signaling pathways. Accordingly, miRNAs can be considered as hallmarks for cancer diagnosis, prognosis and therapy. The purpose of this study was to review the various molecular mechanisms by which TQ exerts its potential as an anti-cancer agent through modulating miRNAs.
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Affiliation(s)
- Mina Homayoonfal
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Islamic Republic of Iran
| | - Zatollah Asemi
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Islamic Republic of Iran
| | - Bahman Yousefi
- Molecular Medicine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Biochemistry, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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15
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Hauke L, Narasimhan S, Primeßnig A, Kaverina I, Rehfeldt F. A Focal Adhesion Filament Cross-correlation Kit for fast, automated segmentation and correlation of focal adhesions and actin stress fibers in cells. PLoS One 2021; 16:e0250749. [PMID: 34506490 PMCID: PMC8432882 DOI: 10.1371/journal.pone.0250749] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 08/23/2021] [Indexed: 11/18/2022] Open
Abstract
Focal adhesions (FAs) and associated actin stress fibers (SFs) form a complex mechanical system that mediates bidirectional interactions between cells and their environment. This linked network is essential for mechanosensing, force production and force transduction, thus directly governing cellular processes like polarization, migration and extracellular matrix remodeling. We introduce a tool for fast and robust coupled analysis of both FAs and SFs named the Focal Adhesion Filament Cross-correlation Kit (FAFCK). Our software can detect and record location, axes lengths, area, orientation, and aspect ratio of focal adhesion structures as well as the location, length, width and orientation of actin stress fibers. This enables users to automate analysis of the correlation of FAs and SFs and study the stress fiber system in a higher degree, pivotal to accurately evaluate transmission of mechanocellular forces between a cell and its surroundings. The FAFCK is particularly suited for unbiased and systematic quantitative analysis of FAs and SFs necessary for novel approaches of traction force microscopy that uses the additional data from the cellular side to calculate the stress distribution in the substrate. For validation and comparison with other tools, we provide datasets of cells of varying quality that are labelled by a human expert. Datasets and FAFCK are freely available as open source under the GNU General Public License.
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Affiliation(s)
- Lara Hauke
- Third Institute of Physics—Biophysics, Georg-August-University Göttingen, Göttingen, Germany
| | - Shwetha Narasimhan
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, United States of America
| | - Andreas Primeßnig
- Third Institute of Physics—Biophysics, Georg-August-University Göttingen, Göttingen, Germany
| | - Irina Kaverina
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, United States of America
- * E-mail: (IK); (FR)
| | - Florian Rehfeldt
- Third Institute of Physics—Biophysics, Georg-August-University Göttingen, Göttingen, Germany
- Experimental Physics I, University of Bayreuth, Bayreuth, Germany
- * E-mail: (IK); (FR)
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16
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Nishimura Y, Shi S, Li Q, Bershadsky AD, Viasnoff V. Crosstalk between myosin II and formin functions in the regulation of force generation and actomyosin dynamics in stress fibers. Cells Dev 2021; 168:203736. [PMID: 34455135 DOI: 10.1016/j.cdev.2021.203736] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/23/2021] [Accepted: 08/16/2021] [Indexed: 10/20/2022]
Abstract
REF52 fibroblasts have a well-developed contractile machinery, the most prominent elements of which are actomyosin stress fibers with highly ordered organization of actin and myosin IIA filaments. The relationship between contractile activity and turnover dynamics of stress fibers is not sufficiently understood. Here, we simultaneously measured the forces exerted by stress fibers (using traction force microscopy or micropillar array sensors) and the dynamics of actin and myosin (using photoconversion-based monitoring of actin incorporation and high-resolution fluorescence microscopy of myosin II light chain). Our data revealed new features of the crosstalk between myosin II-driven contractility and stress fiber dynamics. During normal stress fiber turnover, actin incorporated all along the stress fibers and not only at focal adhesions. Incorporation of actin into stress fibers/focal adhesions, as well as actin and myosin II filaments flow along stress fibers, strongly depends on myosin II activity. Myosin II-dependent generation of traction forces does not depend on incorporation of actin into stress fibers per se, but still requires formin activity. This previously overlooked function of formins in maintenance of the actin cytoskeleton connectivity could be the main mechanism of formin involvement in traction force generation.
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Affiliation(s)
- Yukako Nishimura
- Mechanobiology Institute, National University of Singapore, T-Lab, 5A Engineering Drive 1, 117411, Singapore; Division of Developmental Physiology, Institute for Genetic Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo 060-0815, Japan
| | - Shidong Shi
- Mechanobiology Institute, National University of Singapore, T-Lab, 5A Engineering Drive 1, 117411, Singapore
| | - Qingsen Li
- IFOM-FIRC Institute of Molecular Oncology, Via Adamello, 16, 20139 Milan, Italy
| | - Alexander D Bershadsky
- Mechanobiology Institute, National University of Singapore, T-Lab, 5A Engineering Drive 1, 117411, Singapore; Department of Molecular Cell Biology, Weizmann Institute of Science, 234 Herzl Street, POB 26, Rehovot 7610001, Israel.
| | - Virgile Viasnoff
- Mechanobiology Institute, National University of Singapore, T-Lab, 5A Engineering Drive 1, 117411, Singapore; CNRS UMI 3639, Singapore; Department of Biological Sciences, National university of Singapore, S3 #05-01, 16 Science Drive 4, 117558, Singapore.
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17
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Erianthridin suppresses non-small-cell lung cancer cell metastasis through inhibition of Akt/mTOR/p70 S6K signaling pathway. Sci Rep 2021; 11:6618. [PMID: 33758209 PMCID: PMC7987990 DOI: 10.1038/s41598-021-85675-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/04/2021] [Indexed: 01/31/2023] Open
Abstract
Cancer metastasis is a major cause of the high mortality rate in lung cancer patients. The cytoskeletal rearrangement and degradation of extracellular matrix are required to facilitate cell migration and invasion and the suppression of these behaviors is an intriguing approach to minimize cancer metastasis. Even though Erianthridin (ETD), a phenolic compound isolated from the Thai orchid Dendrobium formosum exhibits various biological activities, the molecular mechanism of ETD for anti-cancer activity is unclear. In this study, we found that noncytotoxic concentrations of ETD (≤ 50 μM) were able to significantly inhibit cell migration and invasion via disruption of actin stress fibers and lamellipodia formation. The expression of matrix metalloproteinase-2 (MMP-2) and MMP-9 was markedly downregulated in a dose-dependent manner after ETD treatment. Mechanistic studies revealed that protein kinase B (Akt) and its downstream effectors mammalian target of rapamycin (mTOR) and p70 S6 kinase (p70S6K) were strongly attenuated. An in silico study further demonstrated that ETD binds to the protein kinase domain of Akt with both hydrogen bonding and van der Waals interactions. In addition, an in vivo tail vein injection metastasis study demonstrated a significant effect of ETD on the suppression of lung cancer cell metastasis. This study provides preclinical information regarding ETD, which exhibits promising antimetastatic activity against non-small-cell lung cancer through Akt/mTOR/p70S6K-induced actin reorganization and MMPs expression.
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18
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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: 8.8] [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.
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19
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Devi SS, Yadav R, Arya R. Altered Actin Dynamics in Cell Migration of GNE Mutant Cells. Front Cell Dev Biol 2021; 9:603742. [PMID: 33816461 PMCID: PMC8012676 DOI: 10.3389/fcell.2021.603742] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 02/09/2021] [Indexed: 11/27/2022] Open
Abstract
Cell migration is an essential cellular process that requires coordination of cytoskeletal dynamics, reorganization, and signal transduction. The actin cytoskeleton is central in maintaining the cellular structure as well as regulating the mechanisms of cell motility. Glycosylation, particularly sialylation of cell surface proteins like integrins, regulates signal transduction from the extracellular matrix to the cytoskeletal network. The activation of integrin by extracellular cues leads to recruitment of different focal adhesion complex proteins (Src, FAK, paxillin, etc.) and activates the signal including Rho GTPases for the regulation of actin assembly and disassembly. During cell migration, the assembly and disassembly of actin filament provides the essential force for the cell to move. Abnormal sialylation can lead to actin signaling dysfunction leading to aberrant cell migration, one of the main characteristics of cancer and myopathies. In the present study, we have reported altered F-actin to G-actin ratios in GNE mutated cells. These cells exhibit pathologically relevant mutations of GNE (UDP N-acetylneuraminic 2-epimerase/N-acetylmannosamine kinase), a key sialic acid biosynthetic enzyme. It was found that GNE neither affects the actin polymerization nor binds directly to actin. However, mutation in GNE resulted in increased binding of α-actinin to actin filaments. Further, through confocal imaging, GNE was found to be localized in focal adhesion complex along with paxillin. We further elucidated that mutation in GNE resulted in upregulation of RhoA protein and Cofilin activity is downregulated, which could be rescued with Rhosin and chlorogenic acid, respectively. Lastly, mutant in GNE reduced cell migration as implicated from wound healing assay. Our study indicates that molecules altering Cofilin function could significantly revert the cell migration defect due to GNE mutation in sialic acid-deficient cells. We propose cytoskeletal proteins to be alternate drug targets for disorders associated with GNE such as GNE myopathy.
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Affiliation(s)
| | - Rashmi Yadav
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Ranjana Arya
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
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20
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Mechanoadaptive organization of stress fiber subtypes in epithelial cells under cyclic stretches and stretch release. Sci Rep 2020; 10:18684. [PMID: 33122754 PMCID: PMC7596055 DOI: 10.1038/s41598-020-75791-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 10/20/2020] [Indexed: 01/01/2023] Open
Abstract
Cyclic stretch applied to cells induces the reorganization of stress fibers. However, the correlation between the reorganization of stress fiber subtypes and strain-dependent responses of the cytoplasm and nucleus has remained unclear. Here, we investigated the dynamic involvement of stress fiber subtypes in the orientation and elongation of cyclically stretched epithelial cells. We applied uniaxial cyclic stretches at 5%, 10%, and 15% strains to cells followed by the release of the mechanical stretch. Dorsal, transverse arcs, and peripheral stress fibers were mainly involved in the cytoplasm responses whereas perinuclear cap fibers were associated with the reorientation and elongation of the nucleus. Dorsal stress fibers and transverse arcs rapidly responded within 15 min regardless of the strain magnitude to facilitate the subsequent changes in the orientation and elongation of the cytoplasm. The cyclic stretches induced the additional formation of perinuclear cap fibers and their increased number was almost maintained with a slight decline after 2-h-long stretch release. The slow formation and high stability of perinuclear cap fibers were linked to the slow reorientation kinetics and partial morphology recovery of nucleus in the presence or absence of cyclic stretches. The reorganization of stress fiber subtypes occurred in accordance with the reversible distribution of myosin II. These findings allowed us to propose a model for stretch-induced responses of the cytoplasm and nucleus in epithelial cells based on different mechanoadaptive properties of stress fiber subtypes.
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21
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Bhattacharya S, Ghosh A, Maiti S, Ahir M, Debnath GH, Gupta P, Bhattacharjee M, Ghosh S, Chattopadhyay S, Mukherjee P, Adhikary A. Delivery of thymoquinone through hyaluronic acid-decorated mixed Pluronic® nanoparticles to attenuate angiogenesis and metastasis of triple-negative breast cancer. J Control Release 2020; 322:357-374. [DOI: 10.1016/j.jconrel.2020.03.033] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 03/06/2020] [Accepted: 03/23/2020] [Indexed: 02/07/2023]
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22
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Tousley A, Iuliano M, Weisman E, Sapp E, Zhang N, Vodicka P, Alexander J, Aviolat H, Gatune L, Reeves P, Li X, Khvorova A, Ellerby LM, Aronin N, DiFiglia M, Kegel-Gleason KB. Rac1 Activity Is Modulated by Huntingtin and Dysregulated in Models of Huntington's Disease. J Huntingtons Dis 2020; 8:53-69. [PMID: 30594931 PMCID: PMC6398565 DOI: 10.3233/jhd-180311] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Background: Previous studies suggest that Huntingtin, the protein mutated in Huntington’s disease (HD), is required for actin based changes in cell morphology, and undergoes stimulus induced targeting to plasma membranes where it interacts with phospholipids involved in cell signaling. The small GTPase Rac1 is a downstream target of growth factor stimulation and PI 3-kinase activity and is critical for actin dependent membrane remodeling. Objective: To determine if Rac1 activity is impaired in HD or regulated by normal Huntingtin. Methods: Analyses were performed in differentiated control and HD human stem cells and HD Q140/Q140 knock-in mice. Biochemical methods included SDS-PAGE, western blot, immunoprecipitation, affinity chromatography, and ELISA based Rac activity assays. Results: Basal Rac1 activity increased following depletion of Huntingtin with Huntingtin specific siRNA in human primary fibroblasts and in human control neuron cultures. Human cells (fibroblasts, neural stem cells, and neurons) with the HD mutation failed to increase Rac1 activity in response to growth factors. Rac1 activity levels were elevated in striatum of 1.5-month-old HD Q140/Q140 mice and in primary embryonic cortical neurons from HD mice. Affinity chromatography analysis of striatal lysates showed that Huntingtin is in a complex with Rac1, p85α subunit of PI 3-kinase, and the actin bundling protein α-actinin and interacts preferentially with the GTP bound form of Rac1. The HD mutation reduced Huntingtin interaction with p85α. Conclusions: These findings suggest that Huntingtin regulates Rac1 activity as part of a coordinated response to growth factor signaling and this function is impaired early in HD.
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Affiliation(s)
- Adelaide Tousley
- Department of Neurology, Laboratory of Cellular Neurobiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Maria Iuliano
- Department of Neurology, Laboratory of Cellular Neurobiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Elizabeth Weisman
- Department of Neurology, Laboratory of Cellular Neurobiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Ellen Sapp
- Department of Neurology, Laboratory of Cellular Neurobiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Ningzhe Zhang
- Buck Institute for Research on Aging, Novato, CA, USA
| | - Petr Vodicka
- Department of Neurology, Laboratory of Cellular Neurobiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Jonathan Alexander
- Department of Neurology, Laboratory of Cellular Neurobiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Hubert Aviolat
- Department of Neurology, Laboratory of Cellular Neurobiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Leah Gatune
- Department of Neurology, Laboratory of Cellular Neurobiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Patrick Reeves
- Department of Neurology, Laboratory of Cellular Neurobiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Xueyi Li
- Department of Neurology, Laboratory of Cellular Neurobiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Anastasia Khvorova
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | | | - Neil Aronin
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA, USA.,Department of Medicine and Cell Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Marian DiFiglia
- Department of Neurology, Laboratory of Cellular Neurobiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Kimberly B Kegel-Gleason
- Department of Neurology, Laboratory of Cellular Neurobiology, Massachusetts General Hospital, Charlestown, MA, USA
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23
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Senger F, Pitaval A, Ennomani H, Kurzawa L, Blanchoin L, Théry M. Spatial integration of mechanical forces by α-actinin establishes actin network symmetry. J Cell Sci 2019; 132:jcs.236604. [PMID: 31615968 DOI: 10.1242/jcs.236604] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/08/2019] [Indexed: 12/15/2022] Open
Abstract
Cell and tissue morphogenesis depend on the production and spatial organization of tensional forces in the actin cytoskeleton. Actin network architecture is made of distinct modules characterized by specific filament organizations. The assembly of these modules are well described, but their integration in a cellular network is less understood. Here, we investigated the mechanism regulating the interplay between network architecture and the geometry of the extracellular environment of the cell. We found that α-actinin, a filament crosslinker, is essential for network symmetry to be consistent with extracellular microenvironment symmetry. It is required for the interconnection of transverse arcs with radial fibres to ensure an appropriate balance between forces at cell adhesions and across the actin network. Furthermore, this connectivity appeared necessary for the ability of the cell to integrate and to adapt to complex patterns of extracellular cues as they migrate. Our study has unveiled a role of actin filament crosslinking in the spatial integration of mechanical forces that ensures the adaptation of intracellular symmetry axes in accordance with the geometry of extracellular cues.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Fabrice Senger
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorphoLab, 3800, Grenoble, France
| | - Amandine Pitaval
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorphoLab, 3800, Grenoble, France.,Université Grenoble-Alpes, CEA, INRA, CNRS, UMR5168, Interdisciplinary Research Institute of Grenoble, Biomics Lab, 38000 Grenoble, France
| | - Hajer Ennomani
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorphoLab, 3800, Grenoble, France
| | - Laetitia Kurzawa
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorphoLab, 3800, Grenoble, France
| | - Laurent Blanchoin
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorphoLab, 3800, Grenoble, France .,Université Paris Diderot, INSERM, CEA, Hôpital Saint Louis, Institut Universitaire d'Hematologie, UMRS 1160, CytoMorphoLab, 75010 Paris, France
| | - Manuel Théry
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorphoLab, 3800, Grenoble, France .,Université Paris Diderot, INSERM, CEA, Hôpital Saint Louis, Institut Universitaire d'Hematologie, UMRS 1160, CytoMorphoLab, 75010 Paris, France
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24
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Gasilina A, Vitali T, Luo R, Jian X, Randazzo PA. The ArfGAP ASAP1 Controls Actin Stress Fiber Organization via Its N-BAR Domain. iScience 2019; 22:166-180. [PMID: 31785555 PMCID: PMC6889188 DOI: 10.1016/j.isci.2019.11.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 09/30/2019] [Accepted: 11/06/2019] [Indexed: 12/11/2022] Open
Abstract
ASAP1 is a multi-domain ArfGAP that controls cell migration, spreading, and focal adhesion dynamics. Although its GAP activity contributes to remodeling of the actin cytoskeleton, it does not fully explain all cellular functions of ASAP1. Here we find that ASAP1 regulates actin filament assembly directly through its N-BAR domain and controls stress fiber maintenance. ASAP1 depletion caused defects in stress fiber organization. Conversely, overexpression of ASAP1 enhanced actin remodeling. The BAR-PH fragment was sufficient to affect actin. ASAP1 with the BAR domain replaced with the BAR domain of the related ACAP1 did not affect actin. The BAR-PH tandem of ASAP1 bound and bundled actin filaments directly, whereas the presence of the ArfGAP and the C-terminal linker/SH3 domain reduced binding and bundling of filaments by BAR-PH. Together these data provide evidence that ASAP1 may regulate the actin cytoskeleton through direct interaction of the BAR-PH domain with actin filaments.
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Affiliation(s)
- Anjelika Gasilina
- Section on Regulation of Ras Superfamily, Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bldg. 37, Rm. 2042, Bethesda, MD 20892, USA; Department of Biochemistry and Molecular & Cellular Biology, Georgetown University Medical Center, Washington, DC 20007, USA
| | - Teresa Vitali
- Section on Regulation of Ras Superfamily, Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bldg. 37, Rm. 2042, Bethesda, MD 20892, USA
| | - Ruibai Luo
- Section on Regulation of Ras Superfamily, Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bldg. 37, Rm. 2042, Bethesda, MD 20892, USA
| | - Xiaoying Jian
- Section on Regulation of Ras Superfamily, Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bldg. 37, Rm. 2042, Bethesda, MD 20892, USA
| | - Paul A Randazzo
- Section on Regulation of Ras Superfamily, Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bldg. 37, Rm. 2042, Bethesda, MD 20892, USA.
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25
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Abstract
The interactions of cytoskeletal actin filaments with myosin family motors are essential for the integrity and function of eukaryotic cells. They support a wide range of force-dependent functions. These include mechano-transduction, directed transcellular transport processes, barrier functions, cytokinesis, and cell migration. Despite the indispensable role of tropomyosins in the generation and maintenance of discrete actomyosin-based structures, the contribution of individual cytoskeletal tropomyosin isoforms to the structural and functional diversification of the actin cytoskeleton remains a work in progress. Here, we review processes that contribute to the dynamic sorting and targeted distribution of tropomyosin isoforms in the formation of discrete actomyosin-based structures in animal cells and their effects on actin-based motility and contractility.
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26
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The Cytoskeleton-A Complex Interacting Meshwork. Cells 2019; 8:cells8040362. [PMID: 31003495 PMCID: PMC6523135 DOI: 10.3390/cells8040362] [Citation(s) in RCA: 232] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/15/2019] [Accepted: 04/15/2019] [Indexed: 12/22/2022] Open
Abstract
The cytoskeleton of animal cells is one of the most complicated and functionally versatile structures, involved in processes such as endocytosis, cell division, intra-cellular transport, motility, force transmission, reaction to external forces, adhesion and preservation, and adaptation of cell shape. These functions are mediated by three classical cytoskeletal filament types, as follows: Actin, microtubules, and intermediate filaments. The named filaments form a network that is highly structured and dynamic, responding to external and internal cues with a quick reorganization that is orchestrated on the time scale of minutes and has to be tightly regulated. Especially in brain tumors, the cytoskeleton plays an important role in spreading and migration of tumor cells. As the cytoskeletal organization and regulation is complex and many-faceted, this review aims to summarize the findings about cytoskeletal filament types, including substructures formed by them, such as lamellipodia, stress fibers, and interactions between intermediate filaments, microtubules and actin. Additionally, crucial regulatory aspects of the cytoskeletal filaments and the formed substructures are discussed and integrated into the concepts of cell motility. Even though little is known about the impact of cytoskeletal alterations on the progress of glioma, a final point discussed will be the impact of established cytoskeletal alterations in the cellular behavior and invasion of glioma.
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27
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Tousley A, Iuliano M, Weisman E, Sapp E, Richardson H, Vodicka P, Alexander J, Aronin N, DiFiglia M, Kegel-Gleason KB. Huntingtin associates with the actin cytoskeleton and α-actinin isoforms to influence stimulus dependent morphology changes. PLoS One 2019; 14:e0212337. [PMID: 30768638 PMCID: PMC6377189 DOI: 10.1371/journal.pone.0212337] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 01/31/2019] [Indexed: 01/09/2023] Open
Abstract
One response of cells to growth factor stimulus involves changes in morphology driven by the actin cytoskeleton and actin associated proteins which regulate functions such as cell adhesion, motility and in neurons, synaptic plasticity. Previous studies suggest that Huntingtin may be involved in regulating morphology however, there has been limited evidence linking endogenous Huntingtin localization or function with cytoplasmic actin in cells. We found that depletion of Huntingtin in human fibroblasts reduced adhesion and altered morphology and these phenotypes were made worse with growth factor stimulation, whereas the presence of the Huntington's Disease mutation inhibited growth factor induced changes in morphology and increased numbers of vinculin-positive focal adhesions. Huntingtin immunoreactivity localized to actin stress fibers, vinculin-positive adhesion contacts and membrane ruffles in fibroblasts. Interactome data from others has shown that Huntingtin can associate with α-actinin isoforms which bind actin filaments. Mapping studies using a cDNA encoding α-actinin-2 showed that it interacts within Huntingtin aa 399-969. Double-label immunofluorescence showed Huntingtin and α-actinin-1 co-localized to stress fibers, membrane ruffles and lamellar protrusions in fibroblasts. Proximity ligation assays confirmed a close molecular interaction between Huntingtin and α-actinin-1 in human fibroblasts and neurons. Huntingtin silencing with siRNA in fibroblasts blocked the recruitment of α-actinin-1 to membrane foci. These studies support the idea that Huntingtin is involved in regulating adhesion and actin dependent functions including those involving α-actinin.
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Affiliation(s)
- Adelaide Tousley
- Laboratory of Cellular Neurobiology, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Maria Iuliano
- Laboratory of Cellular Neurobiology, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Elizabeth Weisman
- Laboratory of Cellular Neurobiology, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Ellen Sapp
- Laboratory of Cellular Neurobiology, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Heather Richardson
- Laboratory of Cellular Neurobiology, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Petr Vodicka
- Laboratory of Cellular Neurobiology, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Jonathan Alexander
- Laboratory of Cellular Neurobiology, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Neil Aronin
- Department of Medicine and Cell Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Marian DiFiglia
- Laboratory of Cellular Neurobiology, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Kimberly B. Kegel-Gleason
- Laboratory of Cellular Neurobiology, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
- * E-mail:
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28
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Cao Y, Lei Y, Luo Y, Tan T, Du B, Zheng Y, Sun L, Liang Q. The actomyosin network is influenced by NMHC IIA and regulated by Crp F46, which is involved in controlling cell migration. Exp Cell Res 2018; 373:119-131. [PMID: 30336116 DOI: 10.1016/j.yexcr.2018.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 10/28/2022]
Abstract
When a cell migrates, the centrosome positions between the nucleus and the leading edge of migration via the microtubule system. The protein CrpF46 (centrosome-related protein F46) has a known role during mitosis and centrosome duplication. However, how CrpF46 efficiently regulates centrosome-related cell migration is unclear. Here, we report that knockdown of CrpF46 resulted in the disruption of microtubule arrangement, with impaired centrosomal reorientation, and slowed down cell migration. In cells that express low levels of CrpF46, stress fibers were weakened, which could be rescued by recovering Flag-CrpF46. We also found that CrpF46 interacted with non-muscle myosin high chain IIA (NMHC IIA) and that its three coiled-coil domains are pivotal for its binding to NMHC IIA. Additionally, analyses of phosphorylation of NMHC IIA and RLC (regulatory light chain) demonstrated that CrpF46 was associated with myosin IIA during filament formation. Indirect immunofluorescence images indicated that NM IIA filaments were inhibited when CrpF46 was under-expressed. Thus, CrpF46 regulates cell migration by centrosomal reorientation and altering the function of the actomyosin network by controlling specific phosphorylation of myosin.
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Affiliation(s)
- Yang Cao
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, PR China; Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, PR China
| | - Yan Lei
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, PR China; Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, PR China
| | - Yang Luo
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, PR China
| | - Tan Tan
- School of Pharmacology and Biology, University of South China, Hunan Province Cooperative innovation Center for Molecular Target New Drug Study, Hengyang 421001, PR China
| | - Baochen Du
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, PR China
| | - Yanbo Zheng
- The Institute of Medical Biotechnology (IMB) of the Chinese Academy of Medical Sciences, Beijing 100050, PR China
| | - Le Sun
- AbMax Biotechnology Co., Beijing 101111, PR China
| | - Qianjin Liang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, PR China; Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, PR China.
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29
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Park B, Oh S, Jo S, Kang D, Lim J, Jung Y, Lee H, Jun SC. Determination of the molecular assembly of actin and actin-binding proteins using photoluminescence. Colloids Surf B Biointerfaces 2018; 169:462-469. [DOI: 10.1016/j.colsurfb.2018.05.043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 04/26/2018] [Accepted: 05/19/2018] [Indexed: 11/27/2022]
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30
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Kemp JP, Brieher WM. The actin filament bundling protein α-actinin-4 actually suppresses actin stress fibers by permitting actin turnover. J Biol Chem 2018; 293:14520-14533. [PMID: 30049798 DOI: 10.1074/jbc.ra118.004345] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 07/21/2018] [Indexed: 01/07/2023] Open
Abstract
Cells organize actin filaments into contractile bundles known as stress fibers that resist mechanical stress, increase cell adhesion, remodel the extracellular matrix, and maintain tissue integrity. α-actinin is an actin filament bundling protein that is thought to be essential for stress fiber formation and stability. However, previous studies have also suggested that α-actinin might disrupt fibers, making the true function of this biomolecule unclear. Here we use fluorescence imaging to show that kidney epithelial cells depleted of α-actinin-4 via shRNA or CRISPR/Cas9, or expressing a disruptive mutant make more massive stress fibers that are less dynamic than those in WT cells, leading to defects in cell motility and wound healing. The increase in stress fiber mass and stability can be explained, in part, by increased loading of the filament component tropomyosin onto stress fibers in the absence of α-actinin, as monitored via immunofluorescence. We show using imaging and cosedimentation that α-actinin and tropomyosin compete for binding to F-actin and that tropomyosin shields actin filaments from cofilin-mediated disassembly in vitro and in cells. Perturbing tropomyosin in cells lacking α-actinin-4 results in a complete loss of stress fibers. Our results with α-actinin-4 on stress fiber organization are the opposite of what might have been predicted from previous in vitro biochemistry and further highlight how the complex interactions of multiple proteins competing for filament binding lead to unexpected functions for actin-binding proteins in cells.
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Affiliation(s)
| | - William M Brieher
- From the Department of Cell and Developmental Biology, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801
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31
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Focal Adhesions Undergo Longitudinal Splitting into Fixed-Width Units. Curr Biol 2018; 28:2033-2045.e5. [PMID: 29910076 DOI: 10.1016/j.cub.2018.04.073] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 03/12/2018] [Accepted: 04/23/2018] [Indexed: 01/09/2023]
Abstract
Focal adhesions (FAs) and stress fibers (SFs) act in concert during cell motility and in response to the extracellular environment. Although the structures of mature FAs and SFs are well studied, less is known about how they assemble and mature de novo during initial cell spreading. In this study using live-cell Airyscan microscopy, we find that FAs undergo "splitting" during their assembly, in which the FA divides along its longitudinal axis. Before splitting, FAs initially appear as assemblies of multiple linear units (FAUs) of 0.3-μm width. Splitting occurs between FAUs, resulting in mature FAs of either a single FAU or of a small number of FAUs that remain attached at their distal tips. Variations in splitting occur based on cell type and extracellular matrix. Depletion of adenomatous polyposis coli (APC) or vasodilator-stimulated phosphoprotein (VASP) results in reduced splitting. FA-associated tension increases progressively during splitting. Early in cell spreading, ventral SFs are detected first, with other SF sub-types (transverse arcs and dorsal SFs) being detected later. Our findings suggest that the fundamental unit of FAs is the fixed-width FAU, and that dynamic interactions between FAUs control adhesion morphology.
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32
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Kovac B, Mäkelä TP, Vallenius T. Increased α-actinin-1 destabilizes E-cadherin-based adhesions and associates with poor prognosis in basal-like breast cancer. PLoS One 2018; 13:e0196986. [PMID: 29742177 PMCID: PMC5942811 DOI: 10.1371/journal.pone.0196986] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 04/24/2018] [Indexed: 01/04/2023] Open
Abstract
The controlled formation and stabilization of E-cadherin-based adhesions is vital for epithelial integrity. This requires co-operation between the E-cadherin-based adhesions and the associated actin cytoskeleton. In cancer, this co-operation often fails, predisposing cells to migration through molecular mechanisms that have only been partially characterized. Here, we demonstrate that the actin filament cross-linker α-actinin-1 is frequently increased in human breast cancer. In mammary epithelial cells, the increased α-actinin-1 levels promote cell migration and induce disorganized acini-like structures in Matrigel. This is accompanied by a major reorganization of the actin cytoskeleton and the associated E-cadherin-based adhesions. Increased expression of α-actinin-1 is particularly noted in basal-like breast cancer cell lines, and in breast cancer patients it associates with poor prognosis in basal-like subtypes. Downregulation of α-actinin-1 in E-cadherin expressing basal-like breast cancer cells demonstrate that α-actinin-1-assembled actin fibers destabilize E-cadherin-based adhesions. Taken together, these results indicate that increased α-actinin-1 expression destabilizes E-cadherin-based adhesions, which is likely to promote the migratory potential of breast cancer cells. Furthermore, our results identify α-actinin-1 as a candidate prognostic biomarker in basal-like breast cancer.
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Affiliation(s)
- Bianca Kovac
- Research Programs Unit, Faculty of Medicine and Helsinki Institute of Life Science HiLIFE, University of Helsinki, Biomedicum Helsinki, Helsinki, Finland
| | - Tomi P. Mäkelä
- Research Programs Unit, Faculty of Medicine and Helsinki Institute of Life Science HiLIFE, University of Helsinki, Biomedicum Helsinki, Helsinki, Finland
| | - Tea Vallenius
- Research Programs Unit, Faculty of Medicine and Helsinki Institute of Life Science HiLIFE, University of Helsinki, Biomedicum Helsinki, Helsinki, Finland
- * E-mail:
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33
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Kuragano M, Uyeda TQP, Kamijo K, Murakami Y, Takahashi M. Different contributions of nonmuscle myosin IIA and IIB to the organization of stress fiber subtypes in fibroblasts. Mol Biol Cell 2018; 29:911-922. [PMID: 29467250 PMCID: PMC5896930 DOI: 10.1091/mbc.e17-04-0215] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 02/14/2018] [Accepted: 02/16/2018] [Indexed: 12/25/2022] Open
Abstract
We demonstrated that myosin IIA and IIB are essential for the formation of transverse arcs and ventral stress fibers, respectively. Furthermore, we illustrated the roles of both isoforms in lamellar flattening and also raised the possibility that actin filaments in ventral stress fibers are in a stretched conformation.
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Affiliation(s)
- Masahiro Kuragano
- Graduate School of Chemical Science and Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
| | - Taro Q. P. Uyeda
- Department of Physics, Faculty of Science and Engineering, Waseda University, Tokyo 169-8555, Japan
| | - Keiju Kamijo
- Department of Anatomy, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi 981-8558, Japan
| | - Yota Murakami
- Graduate School of Chemical Science and Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Masayuki Takahashi
- Graduate School of Chemical Science and Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
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34
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Shutova MS, Asokan SB, Talwar S, Assoian RK, Bear JE, Svitkina TM. Self-sorting of nonmuscle myosins IIA and IIB polarizes the cytoskeleton and modulates cell motility. J Cell Biol 2017; 216:2877-2889. [PMID: 28701425 PMCID: PMC5584186 DOI: 10.1083/jcb.201705167] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 06/16/2017] [Accepted: 06/20/2017] [Indexed: 01/21/2023] Open
Abstract
Nonmuscle myosin II (NMII) is uniquely responsible for cell contractility and thus defines multiple aspects of cell behavior. To generate contraction, NMII molecules polymerize into bipolar minifilaments. Different NMII paralogs are often coexpressed in cells and can copolymerize, suggesting that they may cooperate to facilitate cell motility. However, whether such cooperation exists and how it may work remain unknown. We show that copolymerization of NMIIA and NMIIB followed by their differential turnover leads to self-sorting of NMIIA and NMIIB along the front-rear axis, thus producing a polarized actin-NMII cytoskeleton. Stress fibers newly formed near the leading edge are enriched in NMIIA, but over time, they become progressively enriched with NMIIB because of faster NMIIA turnover. In combination with retrograde flow, this process results in posterior accumulation of more stable NMIIB-rich stress fibers, thus strengthening cell polarity. By copolymerizing with NMIIB, NMIIA accelerates the intrinsically slow NMIIB dynamics, thus increasing cell motility and traction and enabling chemotaxis.
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Affiliation(s)
- Maria S Shutova
- Department of Biology, University of Pennsylvania, Philadelphia, PA
| | - Sreeja B Asokan
- Department of Cell Biology and Physiology, UNC Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Shefali Talwar
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA
| | - Richard K Assoian
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA
| | - James E Bear
- Department of Cell Biology and Physiology, UNC Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
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35
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Maninova M, Caslavsky J, Vomastek T. The assembly and function of perinuclear actin cap in migrating cells. PROTOPLASMA 2017; 254:1207-1218. [PMID: 28101692 DOI: 10.1007/s00709-017-1077-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/09/2017] [Indexed: 05/24/2023]
Abstract
Stress fibers are actin bundles encompassing actin filaments, actin-crosslinking, and actin-associated proteins that represent the major contractile system in the cell. Different types of stress fibers assemble in adherent cells, and they are central to diverse cellular processes including establishment of the cell shape, morphogenesis, cell polarization, and migration. Stress fibers display specific cellular organization and localization, with ventral fibers present at the basal side, and dorsal fibers and transverse actin arcs rising at the cell front from the ventral to the dorsal side and toward the nucleus. Perinuclear actin cap fibers are a specific subtype of stress fibers that rise from the leading edge above the nucleus and terminate at the cell rear forming a dome-like structure. Perinuclear actin cap fibers are fixed at three points: both ends are anchored in focal adhesions, while the central part is physically attached to the nucleus and nuclear lamina through the linker of nucleoskeleton and cytoskeleton (LINC) complex. Here, we discuss recent work that provides new insights into the mechanism of assembly and the function of these actin stress fibers that directly link extracellular matrix and focal adhesions with the nuclear envelope.
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Affiliation(s)
- Miloslava Maninova
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 00, Prague, Czech Republic
| | - Josef Caslavsky
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 00, Prague, Czech Republic
| | - Tomas Vomastek
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 00, Prague, Czech Republic.
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36
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Geometry and network connectivity govern the mechanics of stress fibers. Proc Natl Acad Sci U S A 2017; 114:2622-2627. [PMID: 28213499 DOI: 10.1073/pnas.1606649114] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Actomyosin stress fibers (SFs) play key roles in driving polarized motility and generating traction forces, yet little is known about how tension borne by an individual SF is governed by SF geometry and its connectivity to other cytoskeletal elements. We now address this question by combining single-cell micropatterning with subcellular laser ablation to probe the mechanics of single, geometrically defined SFs. The retraction length of geometrically isolated SFs after cutting depends strongly on SF length, demonstrating that longer SFs dissipate more energy upon incision. Furthermore, when cell geometry and adhesive spacing are fixed, cell-to-cell heterogeneities in SF dissipated elastic energy can be predicted from varying degrees of physical integration with the surrounding network. We apply genetic, pharmacological, and computational approaches to demonstrate a causal and quantitative relationship between SF connectivity and mechanics for patterned cells and show that similar relationships hold for nonpatterned cells allowed to form cell-cell contacts in monolayer culture. Remarkably, dissipation of a single SF within a monolayer induces cytoskeletal rearrangements in cells long distances away. Finally, stimulation of cell migration leads to characteristic changes in network connectivity that promote SF bundling at the cell rear. Our findings demonstrate that SFs influence and are influenced by the networks in which they reside. Such higher order network interactions contribute in unexpected ways to cell mechanics and motility.
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37
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Cheng HW, Chen YF, Wong JM, Weng CW, Chen HY, Yu SL, Chen HW, Yuan A, Chen JJW. Cancer cells increase endothelial cell tube formation and survival by activating the PI3K/Akt signalling pathway. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2017; 36:27. [PMID: 28173828 PMCID: PMC5296960 DOI: 10.1186/s13046-017-0495-3] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 01/27/2017] [Indexed: 01/28/2023]
Abstract
Background Angiogenesis is a hallmark of cancer and plays a critical role in lung cancer progression, which involves interactions between cancer cells, endothelial cells and the surrounding microenvironment. However, the gene expression profiles and the changes in the biological phenotype of vascular endothelial cells after interactions with lung cancer cells remain unclear. Methods An indirect transwell co-culture system was used to survey the interaction between human umbilical vein endothelial cells (HUVECs) and human lung adenocarcinoma CL1-5 cells, as well as to investigate the morphological and molecular changes of HUVECs. The differentially expressed genes (DEGs) in HUVECs after co-culture with cancer cells were identified by microarray. Moreover, a publicly available microarray dataset of 293 non-small-cell lung cancer (NSCLC) patients was employed to evaluate the prognostic power of the gene signatures derived from HUVECs. Results The interaction between HUVECs and lung cancer cells changes the morphology of HUVECs, causing them to have a mesenchymal-like morphology and alter their cytoskeleton organization. Furthermore, after co-culture with lung cancer cells, HUVECs showed increased cell motility and microvessel tube formation ability and a decreased apoptotic percentage. Transcriptomic profiling of HUVECs revealed that many survival-, apoptosis- and angiogenesis-related genes were differentially expressed after interactions with lung cancer cells. Further investigations showed that the PI3K/Akt signalling pathway and COX-2 are involved in endothelial tube formation under the stimulation of lung cancer cells. Moreover, Rac-1 activation might promote endothelial cell motility through the increased formation of lamellipodia and filopodia. The inhibitors of PI3K and COX-2 could reverse the increased tube formation and induce the apoptosis of HUVECs. In addition, the gene signatures derived from the DEGs in HUVECs could predict overall survival and disease-free survival in NSCLC patients and serve as an independent prognostic factor. Conclusions In this study, we found that cancer cells can promote endothelial cell tube formation and survival, at least in part, through the PI3K/Akt signalling pathway and thus change the microenvironment to benefit tumour growth. The gene signatures from HUVECs are associated with the clinical outcome of NSCLC patients. Electronic supplementary material The online version of this article (doi:10.1186/s13046-017-0495-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hao-Wei Cheng
- Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan
| | - Yi-Fang Chen
- Graduate Institute of Clinical Dentistry, National Taiwan University, Taipei, Taiwan
| | - Jau-Min Wong
- Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.,Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Chia-Wei Weng
- Institute of Biomedical Sciences, National Chung-Hsing University, Taichung, Taiwan
| | - Hsuan-Yu Chen
- Institute of Statistical Science, Academia Sinica, Taipei, Taiwan
| | - Sung-Liang Yu
- Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Huei-Wen Chen
- Graduate Institute of Toxicology, National Taiwan University, Taipei, Taiwan
| | - Ang Yuan
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan. .,Department of Emergency Medicine, National Taiwan University Hospital, Taipei, Taiwan.
| | - Jeremy J W Chen
- Institute of Biomedical Sciences, National Chung-Hsing University, Taichung, Taiwan. .,Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan.
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38
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Tanja Mierke C. Physical role of nuclear and cytoskeletal confinements in cell migration mode selection and switching. AIMS BIOPHYSICS 2017. [DOI: 10.3934/biophy.2017.4.615] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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39
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Abstract
Mechanotransduction is the process through which cells survey the mechanical properties of their environment, convert these mechanical inputs into biochemical signals, and modulate their phenotype in response. These mechanical inputs, which may be encoded in the form of extracellular matrix stiffness, dimensionality, and adhesion, all strongly influence cell morphology, migration, and fate decisions. One mechanism through which cells on planar or pseudo-planar matrices exert tensile forces and interrogate microenvironmental mechanics is through stress fibers, which are bundles composed of actin filaments and, in most cases, non-muscle myosin II filaments. Stress fibers form a continuous structural network that is mechanically coupled to the extracellular matrix through focal adhesions. Furthermore, myosin-driven contractility plays a central role in the ability of stress fibers to sense matrix mechanics and generate tension. Here, we review the distinct roles that non-muscle myosin II plays in driving mechanosensing and focus specifically on motility. In a closely related discussion, we also describe stress fiber classification schemes and the differing roles of various myosin isoforms in each category. Finally, we briefly highlight recent studies exploring mechanosensing in three-dimensional environments, in which matrix content, structure, and mechanics are often tightly interrelated. Stress fibers and the myosin motors therein represent an intriguing and functionally important biological system in which mechanics, biochemistry, and architecture all converge.
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Affiliation(s)
- Stacey Lee
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, 94720, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Sanjay Kumar
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, 94720, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, CA, 94720, USA; Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
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40
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Chronopoulos A, Robinson B, Sarper M, Cortes E, Auernheimer V, Lachowski D, Attwood S, García R, Ghassemi S, Fabry B, Del Río Hernández A. ATRA mechanically reprograms pancreatic stellate cells to suppress matrix remodelling and inhibit cancer cell invasion. Nat Commun 2016; 7:12630. [PMID: 27600527 PMCID: PMC5023948 DOI: 10.1038/ncomms12630] [Citation(s) in RCA: 204] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 07/18/2016] [Indexed: 12/13/2022] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a dismal survival rate. Persistent activation of pancreatic stellate cells (PSCs) can perturb the biomechanical homoeostasis of the tumour microenvironment to favour cancer cell invasion. Here we report that ATRA, an active metabolite of vitamin A, restores mechanical quiescence in PSCs via a mechanism involving a retinoic acid receptor beta (RAR-β)-dependent downregulation of actomyosin (MLC-2) contractility. We show that ATRA reduces the ability of PSCs to generate high traction forces and adapt to extracellular mechanical cues (mechanosensing), as well as suppresses force-mediated extracellular matrix remodelling to inhibit local cancer cell invasion in 3D organotypic models. Our findings implicate a RAR-β/MLC-2 pathway in peritumoural stromal remodelling and mechanosensory-driven activation of PSCs, and further suggest that mechanical reprogramming of PSCs with retinoic acid derivatives might be a viable alternative to stromal ablation strategies for the treatment of PDAC. Persistent activation of pancreatic stellate cells (PSCs) can perturb the biomechanical homeostasis of the tumour microenvironment. Here the authors show that all-trans retinoic acid reduces retinoic acid receptor beta dependent-actomyosin contractility and restores mechanical quiescence in PSCs.
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Affiliation(s)
- Antonios Chronopoulos
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Benjamin Robinson
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Muge Sarper
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Ernesto Cortes
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Vera Auernheimer
- Department of Physics, Biophysics Group, University of Erlangen-Nuremberg, Erlangen 91054, Germany
| | - Dariusz Lachowski
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Simon Attwood
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Rebeca García
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Saba Ghassemi
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Ben Fabry
- Department of Physics, Biophysics Group, University of Erlangen-Nuremberg, Erlangen 91054, Germany
| | - Armando Del Río Hernández
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
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41
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Maninová M, Vomastek T. Dorsal stress fibers, transverse actin arcs, and perinuclear actin fibers form an interconnected network that induces nuclear movement in polarizing fibroblasts. FEBS J 2016; 283:3676-3693. [PMID: 27538255 DOI: 10.1111/febs.13836] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 06/30/2016] [Accepted: 08/16/2016] [Indexed: 12/12/2022]
Abstract
In polarized motile cells, stress fibers display specific three-dimensional organization. Ventral stress fibers, attached to focal adhesions at both ends, are restricted to the basal side of the cell and nonprotruding cell sides. Dorsal fibers, transverse actin arcs, and perinuclear actin fibers emanate from protruding cell front toward the nucleus and toward apical side of the cell. Perinuclear cap fibers further extend above the nucleus, associate with nuclear envelope through LINC (linker of nucleoskeleton and cytoskeleton) complex and terminate in focal adhesions at cell rear. How are perinuclear actin fibers formed is poorly understood. We show that the formation of perinuclear actin fibers requires dorsal stress fibers that polymerize from focal adhesions at leading edge, and transverse actin arcs that are interconnected with dorsal fibers in spots rich in α-actinin-1. During cell polarization, the interconnected dorsal fibers and transverse arcs move from leading edge toward dorsal side of the cell. As they move, transverse arcs associate with one end of stress fibers present at nonprotruding cell sides, move them above the nucleus thus forming perinuclear actin fibers. Furthermore, the formation of perinuclear actin fibers induces temporal rotational movement of the nucleus resulting in nuclear reorientation to the direction of migration. These results suggest that the network of dorsal fibers, transverse arcs, and perinuclear fibers transfers mechanical signal between the focal adhesions and nuclear envelope that regulates the nuclear reorientation in polarizing cells.
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Affiliation(s)
| | - Tomáš Vomastek
- Institute of Microbiology AS CR, Prague, Czech Republic.
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42
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Marei H, Carpy A, Macek B, Malliri A. Proteomic analysis of Rac1 signaling regulation by guanine nucleotide exchange factors. Cell Cycle 2016; 15:1961-74. [PMID: 27152953 PMCID: PMC4968972 DOI: 10.1080/15384101.2016.1183852] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 04/13/2016] [Accepted: 04/22/2016] [Indexed: 10/30/2022] Open
Abstract
The small GTPase Rac1 is implicated in various cellular processes that are essential for normal cell function. Deregulation of Rac1 signaling has also been linked to a number of diseases, including cancer. The diversity of Rac1 functioning in cells is mainly attributed to its ability to bind to a multitude of downstream effectors following activation by Guanine nucleotide Exchange Factors (GEFs). Despite the identification of a large number of Rac1 binding partners, factors influencing downstream specificity are poorly defined, thus hindering the detailed understanding of both Rac1's normal and pathological functions. In a recent study, we demonstrated a role for 2 Rac-specific GEFs, Tiam1 and P-Rex1, in mediating Rac1 anti- versus pro-migratory effects, respectively. Importantly, via conducting a quantitative proteomic screen, we identified distinct changes in the Rac1 interactome following activation by either GEF, indicating that these opposing effects are mediated through GEF modulation of the Rac1 interactome. Here, we present the full list of identified Rac1 interactors together with functional annotation of the differentially regulated Rac1 binding partners. In light of this data, we also provide additional insights into known and novel signaling cascades that might account for the GEF-mediated Rac1-driven cellular effects.
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Affiliation(s)
- Hadir Marei
- Cell Signaling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, UK
| | - Alejandro Carpy
- Proteome Center Tuebingen, Interfaculty Institute for Cell Biology, University of Tuebingen, Tuebingen, Germany
| | - Boris Macek
- Proteome Center Tuebingen, Interfaculty Institute for Cell Biology, University of Tuebingen, Tuebingen, Germany
| | - Angeliki Malliri
- Cell Signaling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, UK
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43
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Guo H, Cheng Y, Martinka M, McElwee K. High LIFr expression stimulates melanoma cell migration and is associated with unfavorable prognosis in melanoma. Oncotarget 2016; 6:25484-98. [PMID: 26329521 PMCID: PMC4694846 DOI: 10.18632/oncotarget.4688] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 07/13/2015] [Indexed: 11/25/2022] Open
Abstract
Increased or decreased expression of LIF receptor (LIFr) has been reported in several human cancers, including skin cancer, but its role in melanoma is unknown. In this study, we investigated the expression pattern of LIFr in melanoma and assessed its prognostic value. Using tissue microarrays consisting of 441 melanomas and 96 nevi, we found that no normal nevi showed high LIFr expression. LIFr staining was significantly increased in primary melanoma compared to dysplastic nevi (P = 0.0003) and further increased in metastatic melanoma (P = 0.0000). Kaplan–Meier survival curve and univariate Cox regression analyses showed that increased expression of LIFr was correlated with poorer 5-year patient survival (overall survival, P = 0.0000; disease-specific survival, P = 0.0000). Multivariate Cox regression analyses indicated that increased LIFr expression was an independent prognostic marker for primary melanoma (P = 0.036). LIFr knockdown inhibited melanoma cell migration in wound healing assays and reduced stress fiber formation. LIFr knockdown correlated with STAT3 suppression, but not YAP, suggesting that LIFr activation might stimulate melanoma cell migration through the STAT3 pathway. Our data indicate that strong LIFr expression identifies potentially highly malignant melanocytic lesions at an early stage and LIFr may be a potential target for the development of early intervention therapeutics.
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Affiliation(s)
- Hongwei Guo
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, Canada.,Department of Dermatology, Affiliated Hospital of Guangdong Medical College, Zhanjiang, Guangdong, China
| | - Yabin Cheng
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, Canada
| | - Magdalena Martinka
- Department of Pathology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kevin McElwee
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, Canada
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44
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The actin crosslinking protein palladin modulates force generation and mechanosensitivity of tumor associated fibroblasts. Sci Rep 2016; 6:28805. [PMID: 27353427 PMCID: PMC4926206 DOI: 10.1038/srep28805] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 06/10/2016] [Indexed: 01/15/2023] Open
Abstract
Cells organize actin filaments into higher-order structures by regulating the composition, distribution and concentration of actin crosslinkers. Palladin is an actin crosslinker found in the lamellar actin network and stress fibers, which are critical for mechanosensing of the environment. Palladin also serves as a molecular scaffold for α-actinin, another key actin crosslinker. By virtue of its close interactions with actomyosin structures in the cell, palladin may play an important role in cell mechanics. However, the role of palladin in cellular force generation and mechanosensing has not been studied. Here, we investigate the role of palladin in regulating the plasticity of the actin cytoskeleton and cellular force generation in response to alterations in substrate stiffness. Traction force microscopy revealed that tumor-associated fibroblasts generate larger forces on substrates of increased stiffness. Contrary to expectations, knocking down palladin increased the forces generated by cells and inhibited their ability to sense substrate stiffness for very stiff gels. This was accompanied by significant differences in actin organization, adhesion dynamics and altered myosin organization in palladin knock-down cells. Our results suggest that actin crosslinkers such as palladin and myosin motors coordinate for optimal cell function and to prevent aberrant behavior as in cancer metastasis.
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45
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Drmota Prebil S, Slapšak U, Pavšič M, Ilc G, Puž V, de Almeida Ribeiro E, Anrather D, Hartl M, Backman L, Plavec J, Lenarčič B, Djinović-Carugo K. Structure and calcium-binding studies of calmodulin-like domain of human non-muscle α-actinin-1. Sci Rep 2016; 6:27383. [PMID: 27272015 PMCID: PMC4895382 DOI: 10.1038/srep27383] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 05/16/2016] [Indexed: 12/11/2022] Open
Abstract
The activity of several cytosolic proteins critically depends on the concentration of calcium ions. One important intracellular calcium-sensing protein is α-actinin-1, the major actin crosslinking protein in focal adhesions and stress fibers. The actin crosslinking activity of α-actinin-1 has been proposed to be negatively regulated by calcium, but the underlying molecular mechanisms are poorly understood. To address this, we determined the first high-resolution NMR structure of its functional calmodulin-like domain (CaMD) in calcium-bound and calcium-free form. These structures reveal that in the absence of calcium, CaMD displays a conformationally flexible ensemble that undergoes a structural change upon calcium binding, leading to limited rotation of the N- and C-terminal lobes around the connecting linker and consequent stabilization of the calcium-loaded structure. Mutagenesis experiments, coupled with mass-spectrometry and isothermal calorimetry data designed to validate the calcium binding stoichiometry and binding site, showed that human non-muscle α-actinin-1 binds a single calcium ion within the N-terminal lobe. Finally, based on our structural data and analogy with other α-actinins, we provide a structural model of regulation of the actin crosslinking activity of α-actinin-1 where calcium induced structural stabilisation causes fastening of the juxtaposed actin binding domain, leading to impaired capacity to crosslink actin.
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Affiliation(s)
- Sara Drmota Prebil
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Urška Slapšak
- Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
| | - Miha Pavšič
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Gregor Ilc
- Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia.,EN-FIST Centre of Excellence, Trg Osvobodilne fronte 13, SI-1000 Ljubljana, Slovenia
| | - Vid Puž
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Euripedes de Almeida Ribeiro
- Department of Structural and Computational Biology, Max F. Perutz Laboratories (MFPL), University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Dorothea Anrather
- Mass Spectrometry Service Facility, Max F. Perutz Laboratories (MFPL), University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, A-1030 Vienna, Austria
| | - Markus Hartl
- Mass Spectrometry Service Facility, Max F. Perutz Laboratories (MFPL), University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, A-1030 Vienna, Austria
| | - Lars Backman
- Department of Chemistry, Umeå University, Linnaeus väg 10, SE-90187 Umeå, Sweden
| | - Janez Plavec
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia.,Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia.,EN-FIST Centre of Excellence, Trg Osvobodilne fronte 13, SI-1000 Ljubljana, Slovenia
| | - Brigita Lenarčič
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia.,Department of Biochemistry, Molecular Biology and Structural Biology, Jožef Stefan Institute, Jamova 39,SI-1000 Ljubljana, Slovenia
| | - Kristina Djinović-Carugo
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia.,Department of Structural and Computational Biology, Max F. Perutz Laboratories (MFPL), University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
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46
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Kai F, Fawcett JP, Duncan R. Synaptopodin-2 induces assembly of peripheral actin bundles and immature focal adhesions to promote lamellipodia formation and prostate cancer cell migration. Oncotarget 2016; 6:11162-74. [PMID: 25883213 PMCID: PMC4484447 DOI: 10.18632/oncotarget.3578] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 02/10/2015] [Indexed: 01/02/2023] Open
Abstract
Synaptopodin-2 (Synpo2), an actin-binding protein and invasive cancer biomarker, induces formation of complex stress fiber networks in the cell body and promotes PC3 prostate cancer cell migration in response to serum stimulation. The role of these actin networks in enhanced cancer cell migration is unknown. Using time-course analysis and live cell imaging of mock- and Synpo2-transduced PC3 cells, we now show that Synpo2 induces assembly of actin fibers near the cell periphery and Arp2/3-dependent lamellipodia formation. Lamellipodia formed in a non-directional manner or repeatedly changed direction, explaining the enhanced chemokinetic activity of PC3 cells in response to serum stimulation. Myosin contraction promotes retrograde flow of the Synpo2-associated actin filaments at the leading edge and their merger with actin networks in the cell body. Enhanced PC3 cell migration correlates with Synpo2-induced formation of lamellipodia and immature focal adhesions (FAs), but is not dependent on myosin contraction or FA maturation. The previously reported correlation between Synpo2-induced stress fiber assembly and enhanced PC3 cell migration therefore reflects the role of Synpo2 as a newly identified regulator of actin bundle formation and nascent FA assembly near the leading cell edge.
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Affiliation(s)
- FuiBoon Kai
- Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - James P Fawcett
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Roy Duncan
- Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada
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47
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Lehtimäki J, Hakala M, Lappalainen P. Actin Filament Structures in Migrating Cells. Handb Exp Pharmacol 2016; 235:123-152. [PMID: 27469496 DOI: 10.1007/164_2016_28] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell migration is necessary for several developmental processes in multicellular organisms. Furthermore, many physiological processes such as wound healing and immunological events in adult animals are dependent on cell migration. Consequently, defects in cell migration are linked to various diseases including immunological disorders as well as cancer progression and metastasis formation. Cell migration is driven by specific protrusive and contractile actin filament structures, but the types and relative contributions of these actin filament arrays vary depending on the cell type and the environment of the cell. In this chapter, we introduce the most important actin filament structures that contribute to mesenchymal and amoeboid cell migration modes and discuss the mechanisms by which the assembly and turnover of these structures are controlled by various actin-binding proteins.
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Affiliation(s)
- Jaakko Lehtimäki
- Institute of Biotechnology, University of Helsinki, 56, 00014, Helsinki, Finland
| | - Markku Hakala
- Institute of Biotechnology, University of Helsinki, 56, 00014, Helsinki, Finland
| | - Pekka Lappalainen
- Institute of Biotechnology, University of Helsinki, 56, 00014, Helsinki, Finland.
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48
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Tojkander S, Gateva G, Husain A, Krishnan R, Lappalainen P. Generation of contractile actomyosin bundles depends on mechanosensitive actin filament assembly and disassembly. eLife 2015; 4:e06126. [PMID: 26652273 PMCID: PMC4714978 DOI: 10.7554/elife.06126] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 10/15/2015] [Indexed: 12/20/2022] Open
Abstract
Adhesion and morphogenesis of many non-muscle cells are guided by contractile actomyosin bundles called ventral stress fibers. While it is well established that stress fibers are mechanosensitive structures, physical mechanisms by which they assemble, align, and mature have remained elusive. Here we show that arcs, which serve as precursors for ventral stress fibers, undergo lateral fusion during their centripetal flow to form thick actomyosin bundles that apply tension to focal adhesions at their ends. Importantly, this myosin II-derived force inhibits vectorial actin polymerization at focal adhesions through AMPK-mediated phosphorylation of VASP, and thereby halts stress fiber elongation and ensures their proper contractility. Stress fiber maturation additionally requires ADF/cofilin-mediated disassembly of non-contractile stress fibers, whereas contractile fibers are protected from severing. Taken together, these data reveal that myosin-derived tension precisely controls both actin filament assembly and disassembly to ensure generation and proper alignment of contractile stress fibers in migrating cells. DOI:http://dx.doi.org/10.7554/eLife.06126.001 Muscle cells are the best-known example of a cell in the human body that can contract. These cells contain bundles of filaments made of proteins called actin and myosin, which can generate pulling forces. However, many other cells in the human body also rely on similar “contractile actomyosin bundles” to help them stick to each other, to maintain the correct shape or to migrate from one location to another. These bundles in the non-muscle cells are often called “ventral stress fibers”. Ventral stress fibers develop from structures commonly referred to as “arcs”. Previous work has clearly established that ventral stress fibers are sensitive to mechanical forces. However, the underlying mechanism behind this process was not known, and it remained unclear how external forces could promote these actomyosin bundles to assemble, align and mature. Tojkander et al. documented the formation of ventral stress fibers in migrating human cells grown in the laboratory. This revealed that pre-existing arcs fuse with each other to form thicker and more contractile actomyosin bundles. The formation of these bundles then pulls on the two ends of the stress fibers that are attached to sites on the edges of the cell. Tojkander et al. also showed that this tension inactivates a protein called VASP, which is also found at these sites. Inactivating VASP inhibits the construction of actin filaments, which in turn stops the stress fibers from elongating and allows them to contract. Further experiments then revealed that ventral stress fibers are maintained and can even become thicker under a sustained pulling force. Conversely, stress fibers that were not under tension were decorated by proteins that promote the disassembly of actin filaments. This subsequently led to the disappearance of these fibers. Future studies could now examine whether the newly identified pathway, which allows mechanical forces to control the assembly and alignment of stress fibers, is conserved in other cell-types. Furthermore, and because the assembly of such mechanosensitive actomyosin bundles is often defective in cancer cells, it will also be important to study this pathway’s significance in the context of cancer progression. DOI:http://dx.doi.org/10.7554/eLife.06126.002
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Affiliation(s)
- Sari Tojkander
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Gergana Gateva
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Amjad Husain
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, United States
| | - Ramaswamy Krishnan
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, United States
| | - Pekka Lappalainen
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
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49
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Integration of actin dynamics and cell adhesion by a three-dimensional, mechanosensitive molecular clutch. Nat Cell Biol 2015; 17:955-63. [PMID: 26121555 DOI: 10.1038/ncb3191] [Citation(s) in RCA: 376] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 05/15/2015] [Indexed: 12/12/2022]
Abstract
During cell migration, the forces generated in the actin cytoskeleton are transmitted across transmembrane receptors to the extracellular matrix or other cells through a series of mechanosensitive, regulable protein-protein interactions termed the molecular clutch. In integrin-based focal adhesions, the proteins forming this linkage are organized into a conserved three-dimensional nano-architecture. Here we discuss how the physical interactions between the actin cytoskeleton and focal-adhesion-associated molecules mediate force transmission from the molecular clutch to the extracellular matrix.
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Kassianidou E, Kumar S. A biomechanical perspective on stress fiber structure and function. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:3065-74. [PMID: 25896524 DOI: 10.1016/j.bbamcr.2015.04.006] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 04/05/2015] [Accepted: 04/08/2015] [Indexed: 01/11/2023]
Abstract
Stress fibers are actomyosin-based bundles whose structural and contractile properties underlie numerous cellular processes including adhesion, motility and mechanosensing. Recent advances in high-resolution live-cell imaging and single-cell force measurement have dramatically sharpened our understanding of the assembly, connectivity, and evolution of various specialized stress fiber subpopulations. This in turn has motivated interest in understanding how individual stress fibers generate tension and support cellular structure and force generation. In this review, we discuss approaches for measuring the mechanical properties of single stress fibers. We begin by discussing studies conducted in cell-free settings, including strategies based on isolation of intact stress fibers and reconstitution of stress fiber-like structures from purified components. We then discuss measurements obtained in living cells based both on inference of stress fiber properties from whole-cell mechanical measurements (e.g., atomic force microscopy) and on direct interrogation of single stress fibers (e.g., subcellular laser nanosurgery). We conclude by reviewing various mathematical models of stress fiber function that have been developed based on these experimental measurements. An important future challenge in this area will be the integration of these sophisticated biophysical measurements with the field's increasingly detailed molecular understanding of stress fiber assembly, dynamics, and signal transduction. This article is part of a Special Issue entitled: Mechanobiology.
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Affiliation(s)
- Elena Kassianidou
- Department of Bioengineering, University of California, Berkeley, United States
| | - Sanjay Kumar
- Department of Bioengineering, University of California, Berkeley, United States.
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