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Rogers LM, Huggins M, Doster RS, Omage JI, Gaddy JA, Eastman A, Aronoff DM. Impact of Metabolic Stress on BeWo Syncytiotrophoblast Function. Chembiochem 2023; 24:e202300410. [PMID: 37800606 DOI: 10.1002/cbic.202300410] [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: 05/31/2023] [Revised: 10/06/2023] [Accepted: 10/06/2023] [Indexed: 10/07/2023]
Abstract
During placental formation, cytotrophoblasts (CTBs) fuse into multinucleate, microvilli-coated syncytiotrophoblasts (STBs), which contact maternal blood, mediating nutrient, metabolite, and gas exchange between mother and fetus, and providing a barrier against fetal infection. Trophoblasts remodel the surrounding extracellular matrix through the secretion of matrix metalloproteinases (MMPs). Maternal obesity and diabetes mellitus can negatively impact fetal development and may impair trophoblast function. We sought to model the impact of metabolic stress on STB function by examining MMP and hormone secretion. The BeWo CTB cell line was syncytialized to STB-like cells with forskolin. Cell morphology was examined by electron microscopy and immunofluorescence; phenotype was further assessed by ELISA and RT-qPCR. STBs were exposed to a metabolic stress cocktail (MetaC: 30 mM glucose, 10 nM insulin, and 0.1 mM palmitic acid). BeWo syncytialization was demonstrated by increased secretion of HCGβ and progesterone, elevated syncytin gene expression (ERVW-1 and ERVFRD-1), loss of tight junctions, and increased surface microvilli. MetaC strongly suppressed syncytin gene expression (ERVW-1 and ERVFRD-1), suppressed HCGβ and progesterone secretion, and altered both MMP-9 and MMP-2 production. Metabolic stress modeling diabetes and obesity altered BeWo STB hormone and MMP production in vitro.
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Affiliation(s)
- Lisa M Rogers
- Division of Infectious Diseases, Department of Medicine, Indiana University School of Medicine, 545 Barnhill Dr., EH 305, Indianapolis, IN, 46202, USA
| | - Marissa Huggins
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Ryan S Doster
- Division of Infectious Diseases, Department of Medicine, Department of Microbiology and Immunology, University of Louisville, Louisville, KY, 40202, USA
| | - Joel I Omage
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Jennifer A Gaddy
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Alison Eastman
- Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - David M Aronoff
- Division of Infectious Diseases, Department of Medicine, Indiana University School of Medicine, 545 Barnhill Dr., EH 305, Indianapolis, IN, 46202, USA
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2
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Zhang R, Chen S, Yang Z, Zhang N, Guo K, Lv K, Zhou Z, Gao M, Hu X, Su Y, He J, Wang F. Actin polymerization inhibition by targeting ARPC2 affects intestinal stem cell homeostasis. BURNS & TRAUMA 2023; 11:tkad038. [PMID: 37849945 PMCID: PMC10578047 DOI: 10.1093/burnst/tkad038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 04/28/2023] [Accepted: 05/25/2023] [Indexed: 10/19/2023]
Abstract
Background The rapid turnover of the intestinal epithelium is driven by the proliferation and differentiation of intestinal stem cells (ISCs). The dynamics of the F-actin cytoskeleton are critical for maintaining intercellular force and the signal transduction network. However, it remains unclear how direct interference with actin polymerization impacts ISC homeostasis. This study aims to reveal the regulatory effects of the F-actin cytoskeleton on the homeostasis of intestinal epithelium, as well as the potential risks of benproperine (BPP) as an anti-tumor drug. Methods Phalloidin fluorescence staining was utilized to test F-actin polymerization. Flow cytometry and IHC staining were employed to discriminate different types of intestinal epithelial cells. Cell proliferation was assessed through bromo-deoxyuridine (BrdU) and 5-ethynyl-2'-deoxyuridine (EdU) incorporation assays. The proliferation and differentiation of intestinal stem cells were replicated in vitro through organoid culture. Epithelial migration was evaluated through BrdU pulse labeling and chasing in mice. Results The F-actin content was observed to significantly increase as crypt cells migrated into the villus region. Additionally, actin polymerization in secretory cells, especially in Paneth cells (PCs), was much higher than that in neighboring ISCs. Treatment with the newly identified actin-related protein 2/3 complex subunit 2 (ARPC2) inhibitor BPP led to a dose-dependent increase or inhibition of intestinal organoid growth in vitro and crypt cell proliferation in vivo. Compared with the vehicle group, BPP treatment decreased the expression of Lgr5 ISC feature genes in vivo and in organoid culture. Meanwhile, PC differentiation derived from ISCs and progenitors was decreased by inhibition of F-actin polymerization. Mechanistically, BPP-induced actin polymerization inhibition may activate the Yes1-associated transcriptional regulator pathway, which affects ISC proliferation and differentiation. Accordingly, BPP treatment affected intestinal epithelial cell migration in a dose-dependent manner. Conclusion Our findings indicate that the regulation of cytoskeleton reorganization can affect ISC homeostasis. In addition, inhibiting ARPC2 with the Food and Drug Administration-approved drug BPP represents a novel approach to influencing the turnover of intestinal epithelial cells.
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Affiliation(s)
- Ruzhen Zhang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing 400038, China
- College of Life Sciences, Chongqing Normal University,Chongqing, 401331China
| | - Sheng Chen
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing 400038, China
| | - Zhifan Yang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing 400038, China
| | - Ning Zhang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing 400038, China
| | - Kenan Guo
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing 400038, China
- Department of Laboratory Animal Science, College of Basic Medical Sciences, Army Medical University, Third Military Medical University, Chongqing 400038, China
| | - Keyi Lv
- Department of Military Cognitive Psychology, School of Psychology, Third Military Medical University, Chongqing, 400038, China
| | - Zimo Zhou
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing 400038, China
| | - Meijiao Gao
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing 400038, China
| | - Xiancheng Hu
- College of Life Sciences, Chongqing Normal University,Chongqing, 401331China
| | - Yongping Su
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing 400038, China
| | - Jianming He
- Department of Radiotherapy, Hebei Province Hospital of Chinese Medicine, Hebei University of Chinese Medicine, Key Laboratory of Integrated Chinese and Western Medicine for Gastroenterology Research (Hebei), Shijiazhuang, 050011
| | - Fengchao Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing 400038, China
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3
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Sharkova M, Chow E, Erickson T, Hocking JC. The morphological and functional diversity of apical microvilli. J Anat 2023; 242:327-353. [PMID: 36281951 PMCID: PMC9919547 DOI: 10.1111/joa.13781] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/03/2022] [Accepted: 10/05/2022] [Indexed: 11/30/2022] Open
Abstract
Sensory neurons use specialized apical processes to perceive external stimuli and monitor internal body conditions. The apical apparatus can include cilia, microvilli, or both, and is adapted for the functions of the particular cell type. Photoreceptors detect light through a large, modified cilium (outer segment), that is supported by a surrounding ring of microvilli-like calyceal processes (CPs). Although first reported 150 years ago, CPs remain poorly understood. As a basis for future study, we therefore conducted a review of existing literature about sensory cell microvilli, which can act either as the primary sensory detector or as support for a cilia-based detector. While all microvilli are finger-like cellular protrusions with an actin core, the processes vary across cell types in size, number, arrangement, dynamics, and function. We summarize the current state of knowledge about CPs and the characteristics of the microvilli found on inner ear hair cells (stereocilia) and cerebral spinal fluid-contacting neurons, with comparisons to the brush border of the intestinal and renal epithelia. The structure, stability, and dynamics of the actin core are regulated by a complement of actin-binding proteins, which includes both common components and unique features when compared across cell types. Further, microvilli are often supported by lateral links, a glycocalyx, and a defined extracellular matrix, each adapted to the function and environment of the cell. Our comparison of microvillar features will inform further research into how CPs support photoreceptor function, and also provide a general basis for investigations into the structure and functions of apical microvilli found on sensory neurons.
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Affiliation(s)
- Maria Sharkova
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Erica Chow
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Timothy Erickson
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Jennifer C Hocking
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Division of Anatomy, Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada
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4
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Morales EA, Gaeta I, Tyska MJ. Building the brush border, one microvillus at a time. Curr Opin Cell Biol 2023; 80:102153. [PMID: 36827850 PMCID: PMC10033394 DOI: 10.1016/j.ceb.2023.102153] [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: 08/22/2022] [Revised: 01/11/2023] [Accepted: 01/19/2023] [Indexed: 02/24/2023]
Abstract
Microvilli are actin bundle-supported surface protrusions assembled by diverse cell types to mediate biochemical and physical interactions with the external environment. Found on the surface of some of the earliest animal cells, primordial microvilli likely contributed to bacterial entrapment and feeding. Although millions of years of evolution have repurposed these protrusions to fulfill diverse roles such as detection of mechanical or visual stimuli in inner ear hair cells or retinal pigmented epithelial cells, respectively, solute uptake remains a key essential function linked to these structures. In this mini review, we offer a brief overview of the composition and structure of epithelial microvilli, highlight recent discoveries on the growth of these protrusions early in differentiation, and point to fundamental questions surrounding microvilli biogenesis that remain open for future studies.
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Affiliation(s)
- E Angelo Morales
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Isabella Gaeta
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Matthew J Tyska
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA.
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5
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Chandrasekaran A, Giniger E, Papoian GA. Nucleation causes an actin network to fragment into multiple high-density domains. Biophys J 2022; 121:3200-3212. [PMID: 35927959 PMCID: PMC9463697 DOI: 10.1016/j.bpj.2022.07.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/20/2021] [Accepted: 07/28/2022] [Indexed: 11/02/2022] Open
Abstract
Actin networks rely on nucleation mechanisms to generate new filaments because spontaneous nucleation is kinetically disfavored. Branching nucleation of actin filaments by actin-related protein (Arp2/3), in particular, is critical for actin self-organization. In this study, we use the simulation platform for active matter MEDYAN to generate 2000 s long stochastic trajectories of actin networks, under varying Arp2/3 concentrations, in reaction volumes of biologically meaningful size (>20 μm3). We find that the dynamics of Arp2/3 increase the abundance of short filaments and increases network treadmilling rate. By analyzing the density fields of F-actin, we find that at low Arp2/3 concentrations, F-actin is organized into a single connected and contractile domain, while at elevated Arp2/3 levels (10 nM and above), such high-density actin domains fragment into smaller domains spanning a wide range of volumes. These fragmented domains are extremely dynamic, continuously merging and splitting, owing to the high treadmilling rate of the underlying actin network. Treating the domain dynamics as a drift-diffusion process, we find that the fragmented state is stochastically favored, and the network state slowly drifts toward the fragmented state with considerable diffusion (variability) in the number of domains. We suggest that tuning the Arp2/3 concentration enables cells to transition from a globally coherent cytoskeleton, whose response involves the entire cytoplasmic network, to a fragmented cytoskeleton, where domains can respond independently to locally varying signals.
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Affiliation(s)
- Aravind Chandrasekaran
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland; National Institutes of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Edward Giniger
- National Institutes of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Garegin A Papoian
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland; Institute for Physical Science and Technology, University of Maryland, College Park, Maryland.
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6
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Engevik MA, Engevik AC. Myosins and membrane trafficking in intestinal brush border assembly. Curr Opin Cell Biol 2022; 77:102117. [PMID: 35870341 DOI: 10.1016/j.ceb.2022.102117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 06/15/2022] [Accepted: 06/23/2022] [Indexed: 11/29/2022]
Abstract
Myosins are a class of motors that participate in a wide variety of cellular functions including organelle transport, cell adhesion, endocytosis and exocytosis, movement of RNA, and cell motility. Among the emerging roles for myosins is regulation of the assembly, morphology, and function of actin protrusions such as microvilli. The intestine harbors an elaborate apical membrane composed of highly organized microvilli. Microvilli assembly and function are intricately tied to several myosins including Myosin 1a, non-muscle Myosin 2c, Myosin 5b, Myosin 6, and Myosin 7b. Here, we review the research progress made in our understanding of myosin mediated apical assembly.
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Affiliation(s)
- Melinda A Engevik
- Department of Regenerative Medicine & Cell Biology, Medical University of South Carolina
| | - Amy C Engevik
- Department of Regenerative Medicine & Cell Biology, Medical University of South Carolina.
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7
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Bourdais A, Dehapiot B, Halet G. Cofilin regulates actin network homeostasis and microvilli length in mouse oocytes. J Cell Sci 2021; 134:273797. [PMID: 34841429 DOI: 10.1242/jcs.259237] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 11/18/2021] [Indexed: 11/20/2022] Open
Abstract
How multiple actin networks coexist in a common cytoplasm while competing for a shared pool of monomers is still an ongoing question. This is exemplified by meiotic maturation in the mouse oocyte, which relies on the dynamic remodeling of distinct cortical and cytoplasmic F-actin networks. Here, we show that the conserved actin-depolymerizing factor cofilin is activated in a switch-like manner upon meiosis resumption from prophase arrest. Interfering with cofilin activation during maturation resulted in widespread elongation of microvilli, while cytoplasmic F-actin was depleted, leading to defects in spindle migration and polar body extrusion. In contrast, cofilin inactivation in metaphase II-arrested oocytes resulted in a shutdown of F-actin dynamics, along with a dramatic overgrowth of the polarized actin cap. However, inhibition of the Arp2/3 complex to promote actin cap disassembly elicited ectopic microvilli outgrowth in the polarized cortex. These data establish cofilin as a key player in actin network homeostasis in oocytes and reveal that microvilli can act as a sink for monomers upon disassembly of a competing network.
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Affiliation(s)
- Anne Bourdais
- Institut Génétique et Développement de Rennes , CNRS IGDR UMR 6290, Université de Rennes 1, F-35000 Rennes, France
| | - Benoit Dehapiot
- Institut Génétique et Développement de Rennes , CNRS IGDR UMR 6290, Université de Rennes 1, F-35000 Rennes, France
| | - Guillaume Halet
- Institut Génétique et Développement de Rennes , CNRS IGDR UMR 6290, Université de Rennes 1, F-35000 Rennes, France
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8
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Bidaud-Meynard A, Demouchy F, Nicolle O, Pacquelet A, Suman SK, Plancke CN, Robin FB, Michaux G. High-resolution dynamic mapping of the C. elegans intestinal brush border. Development 2021; 148:dev200029. [PMID: 34704594 PMCID: PMC10659032 DOI: 10.1242/dev.200029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/04/2021] [Indexed: 11/20/2022]
Abstract
The intestinal brush border is made of an array of microvilli that increases the membrane surface area for nutrient processing, absorption and host defense. Studies on mammalian cultured epithelial cells have uncovered some of the molecular players and physical constraints required to establish this apical specialized membrane. However, the building and maintenance of a brush border in vivo has not yet been investigated in detail. Here, we combined super-resolution imaging, transmission electron microscopy and genome editing in the developing nematode Caenorhabditis elegans to build a high-resolution and dynamic localization map of known and new brush border markers. Notably, we show that microvilli components are dynamically enriched at the apical membrane during microvilli outgrowth and maturation, but become highly stable once microvilli are built. This new toolbox will be instrumental for understanding the molecular processes of microvilli growth and maintenance in vivo, as well as the effect of genetic perturbations, notably in the context of disorders affecting brush border integrity.
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Affiliation(s)
- Aurélien Bidaud-Meynard
- Université de Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Flora Demouchy
- Université de Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Ophélie Nicolle
- Université de Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Anne Pacquelet
- Université de Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Shashi Kumar Suman
- Sorbonne Université, Institut Biologie Paris Seine, CNRS UMR7622, Developmental Biology Laboratory, Inserm U1156, F-75005 Paris, France
| | - Camille N Plancke
- Sorbonne Université, Institut Biologie Paris Seine, CNRS UMR7622, Developmental Biology Laboratory, Inserm U1156, F-75005 Paris, France
| | - François B Robin
- Sorbonne Université, Institut Biologie Paris Seine, CNRS UMR7622, Developmental Biology Laboratory, Inserm U1156, F-75005 Paris, France
| | - Grégoire Michaux
- Université de Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
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9
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Kadzik RS, Homa KE, Kovar DR. F-Actin Cytoskeleton Network Self-Organization Through Competition and Cooperation. Annu Rev Cell Dev Biol 2021; 36:35-60. [PMID: 33021819 DOI: 10.1146/annurev-cellbio-032320-094706] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Many fundamental cellular processes such as division, polarization, endocytosis, and motility require the assembly, maintenance, and disassembly of filamentous actin (F-actin) networks at specific locations and times within the cell. The particular function of each network is governed by F-actin organization, size, and density as well as by its dynamics. The distinct characteristics of different F-actin networks are determined through the coordinated actions of specific sets of actin-binding proteins (ABPs). Furthermore, a cell typically assembles and uses multiple F-actin networks simultaneously within a common cytoplasm, so these networks must self-organize from a common pool of shared globular actin (G-actin) monomers and overlapping sets of ABPs. Recent advances in multicolor imaging and analysis of ABPs and their associated F-actin networks in cells, as well as the development of sophisticated in vitro reconstitutions of networks with ensembles of ABPs, have allowed the field to start uncovering the underlying principles by which cells self-organize diverse F-actin networks to execute basic cellular functions.
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Affiliation(s)
- Rachel S Kadzik
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637, USA; , .,Department of Molecular BioSciences, Northwestern University, Evanston, Illinois 60208, USA;
| | - Kaitlin E Homa
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637, USA; ,
| | - David R Kovar
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637, USA; , .,Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, USA
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10
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Vedula P, Kurosaka S, MacTaggart B, Ni Q, Papoian G, Jiang Y, Dong DW, Kashina A. Different translation dynamics of β- and γ-actin regulates cell migration. eLife 2021; 10:68712. [PMID: 34165080 PMCID: PMC8328520 DOI: 10.7554/elife.68712] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 06/19/2021] [Indexed: 12/13/2022] Open
Abstract
β- and γ-cytoplasmic actins are ubiquitously expressed in every cell type and are nearly identical at the amino acid level but play vastly different roles in vivo. Their essential roles in embryogenesis and mesenchymal cell migration critically depend on the nucleotide sequences of their genes, rather than their amino acid sequences; however, it is unclear which gene elements underlie this effect. Here we address the specific role of the coding sequence in β- and γ-cytoplasmic actins’ intracellular functions, using stable polyclonal populations of immortalized mouse embryonic fibroblasts with exogenously expressed actin isoforms and their ‘codon-switched’ variants. When targeted to the cell periphery using β-actin 3′UTR; β-actin and γ-actin have differential effects on cell migration. These effects directly depend on the coding sequence. Single-molecule measurements of actin isoform translation, combined with fluorescence recovery after photobleaching, demonstrate a pronounced difference in β- and γ-actins’ translation elongation rates in cells, leading to changes in their dynamics at focal adhesions, impairments in actin bundle formation, and reduced cell anchoring to the substrate during migration. Our results demonstrate that coding sequence-mediated differences in actin translation play a key role in cell migration. Most mammalian cells make both β- and γ-actin, two proteins which shape the cell’s internal skeleton and its ability to migrate. The molecules share over 99% of their sequence, yet they play distinct roles. In fact, deleting the β-actin gene in mice causes death in the womb, while the animals can survive with comparatively milder issues without their γ-actin gene. How two similar proteins can have such different biological roles is a long-standing mystery. A closer look could hold some clues: β- and γ-actin may contain the same blocks (or amino acids), but the genetic sequences that encode these proteins differ by about 13%. This is because different units of genetic information – known as synonymous codons – can encode the same amino acid. These ‘silent substitutions’ have no effect on the sequence of the proteins, yet a cell reads synonymous codons (and therefore produces proteins) at different speeds. To find out the impact of silent substitutions, Vedula et al. swapped the codons for the two proteins, forcing mouse cells to produce β-actin using γ-actin codons, and vice versa. Cells with non-manipulated γ-actin and those with β-actin made using γ-actin codons could move much faster than cells with β-actin. This suggested that silent substitutions were indeed affecting the role of the protein. Vedula et al. found that cells read γ-codons – and therefore made γ-actin – much more slowly than β-codons: this also affected how quickly the protein could be dispatched where it was needed in the cell. Slower production meant that bundles of γ-actin were shorter, which allowed cells to move faster by providing a weaker anchoring system. Overall, this work provides new links between silent substitutions and protein behavior, a relatively new research area which is likely to shed light on other protein families.
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Affiliation(s)
- Pavan Vedula
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, United States
| | - Satoshi Kurosaka
- Institute of Advanced Technology, Kindai University, Kainan, Wakayama, Japan
| | - Brittany MacTaggart
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, United States
| | - Qin Ni
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, United States
| | - Garegin Papoian
- Department of Chemistry, University of Maryland, College Park, United States
| | - Yi Jiang
- Department of Mathematics and Statistics, Georgia State University, Atlanta, United States
| | - Dawei W Dong
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, United States.,Institute for Biomedical Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Anna Kashina
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, United States
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11
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Karlsson R, Dráber P. Profilin-A master coordinator of actin and microtubule organization in mammalian cells. J Cell Physiol 2021; 236:7256-7265. [PMID: 33821475 DOI: 10.1002/jcp.30379] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/08/2021] [Accepted: 03/12/2021] [Indexed: 12/17/2022]
Abstract
The last two decades have witnessed a tremendous increase in cell biology data. Not least is this true for studies of the dynamic organization of the microfilament and microtubule systems in animal cells where analyses of the molecular components and their interaction patterns have deepened our understanding of these complex force-generating machineries. Previous observations of a molecular cross-talk between the two systems have now led to the realization of the existence of several intricate mechanisms operating to maintain their coordinated cellular organization. In this short review, we relate to this development by discussing new results concerning the function of the actin regulator profilin 1 as a control component of microfilament-microtubule cross-talk.
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Affiliation(s)
- Roger Karlsson
- Department of Molecular Biosciences, WGI, Stockholm University, Stockholm, Sweden
| | - Pavel Dráber
- Department of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
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12
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Cebecauer M. Role of Lipids in Morphogenesis of T-Cell Microvilli. Front Immunol 2021; 12:613591. [PMID: 33790891 PMCID: PMC8006438 DOI: 10.3389/fimmu.2021.613591] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 01/13/2021] [Indexed: 11/13/2022] Open
Abstract
T cells communicate with the environment via surface receptors. Cooperation of surface receptors regulates T-cell responses to diverse stimuli. Recently, finger-like membrane protrusions, microvilli, have been demonstrated to play a role in the organization of receptors and, hence, T-cell activation. However, little is known about the morphogenesis of dynamic microvilli, especially in the cells of immune system. In this review, I focus on the potential role of lipids and lipid domains in morphogenesis of microvilli. Discussed is the option that clustering of sphingolipids with phosphoinositides at the plasma membrane results in dimpling (curved) domains. Such domains can attract phosphoinositide-binding proteins and stimulate actin cytoskeleton reorganization. This process triggers cortical actin opening and bundling of actin fibres to support the growing of microvilli. Critical regulators of microvilli morphogenesis in T cells are unknown. At the end, I suggest several candidates with a potential to organize proteins and lipids in these structures.
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Affiliation(s)
- Marek Cebecauer
- Department of Biophysical Chemistry, J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences (CAS), Prague, Czechia
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13
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Modulation of the immune response and metabolism in germ-free rats colonized by the probiotic Lactobacillus salivarius LI01. Appl Microbiol Biotechnol 2021; 105:1629-1645. [PMID: 33507355 DOI: 10.1007/s00253-021-11099-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/21/2020] [Accepted: 01/05/2021] [Indexed: 01/06/2023]
Abstract
The gut microbiota plays an important role in multifaceted physiological functions in the host. Previous studies have assessed the probiotic effects of Lactobacillus salivarius LI01. In this study, we aimed to investigate the potential effects and putative mechanism of L. salivarius LI01 in immune modulation and metabolic regulation through the monocolonization of germ-free (GF) Sprague-Dawley (SD) rats with L. salivarius LI01. The GF rats were separated into two groups and administered a gavage of L. salivarius LI01 or an equal amount of phosphate-buffered saline. The levels of serum biomarkers, such as interleukin (IL)-1α, IL-5, and IL-10, were restored by L. salivarius LI01, which indicated the activation of Th0 cell differentiation toward immune homeostasis. L. salivarius LI01 also stimulated the immune response and metabolic process by altering transcriptional expression in the ileum and liver. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed significant enrichment of the 5'-adenosine monophosphate-activated protein kinase (AMPK) signaling pathway, which indicated that L. salivarius LI01 exerts an effect on energy accumulation. The LI01 group showed alterations in fecal carbohydrates accompanied by an increased body weight gain. In addition, L. salivarius LI01 produced indole-3-lactic acid (ILA) and enhanced arginine metabolism by rebalancing the interconversion between arginine and proline. These findings provide evidence showing that L. salivarius LI01 can directly impact the host by modulating immunity and metabolism. KEY POINTS : • Lactobacillus salivarius LI01 conventionalizes the cytokine profile and activates the immune response. • LI01 modulates carbohydrate metabolism and arginine transaction. • LI01 generates tryptophan-derived indole-3-lactic acid. • The cytochrome P450 family contributes to the response to altered metabolites.
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14
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Ljubojevic N, Henderson JM, Zurzolo C. The Ways of Actin: Why Tunneling Nanotubes Are Unique Cell Protrusions. Trends Cell Biol 2020; 31:130-142. [PMID: 33309107 DOI: 10.1016/j.tcb.2020.11.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/09/2020] [Accepted: 11/16/2020] [Indexed: 12/22/2022]
Abstract
Actin remodeling is at the heart of the response of cells to external or internal stimuli, allowing a variety of membrane protrusions to form. Fifteen years ago, tunneling nanotubes (TNTs) were identified, bringing a novel addition to the family of actin-supported cellular protrusions. Their unique property as conduits for cargo transfer between distant cells emphasizes the unique nature of TNTs among other protrusions. While TNTs in different pathological and physiological scenarios have been described, the molecular basis of how TNTs form is not well understood. In this review, we discuss the role of several actin regulators in the formation of TNTs and suggest potential players based on their comparison with other actin-based protrusions. New perspectives for discovering a distinct TNT formation pathway would enable us to target them in treating the increasing number of TNT-involved pathologies.
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Affiliation(s)
- Nina Ljubojevic
- Membrane Traffic and Pathogenesis, Institut Pasteur, UMR3691 CNRS, 75015 Paris, France; Sorbonne Université, ED394 - Physiologie, Physiopathologie et Thérapeutique, 75005 Paris, France
| | - J Michael Henderson
- Membrane Traffic and Pathogenesis, Institut Pasteur, UMR3691 CNRS, 75015 Paris, France; Laboratoire Physico-Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France
| | - Chiara Zurzolo
- Membrane Traffic and Pathogenesis, Institut Pasteur, UMR3691 CNRS, 75015 Paris, France.
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15
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Weck ML, Crawley SW, Tyska MJ. A heterologous in-cell assay for investigating intermicrovillar adhesion complex interactions reveals a novel protrusion length-matching mechanism. J Biol Chem 2020; 295:16191-16206. [PMID: 33051206 DOI: 10.1074/jbc.ra120.015929] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 09/30/2020] [Indexed: 01/18/2023] Open
Abstract
Solute transporting epithelial cells build arrays of microvilli on their apical surface to increase membrane scaffolding capacity and enhance function potential. In epithelial tissues such as the kidney and gut, microvilli are length-matched and assembled into tightly packed "brush borders," which are organized by ∼50-nm thread-like links that form between the distal tips of adjacent protrusions. Composed of protocadherins CDHR2 and CDHR5, adhesion links are stabilized at the tips by a cytoplasmic tripartite module containing the scaffolds USH1C and ANKS4B and the actin-based motor MYO7B. Because several questions about the formation and function of this "intermicrovillar adhesion complex" remain open, we devised a system that allows one to study individual binary interactions between specific complex components and MYO7B. Our approach employs a chimeric myosin consisting of the MYO10 motor domain fused to the MYO7B cargo-binding tail domain. When expressed in HeLa cells, which do not normally produce adhesion complex proteins, this chimera trafficked to the tips of filopodia and was also able to transport individual complex components to these sites. Unexpectedly, the MYO10-MYO7B chimera was able to deliver CDHR2 and CDHR5 to distal tips in the absence of USH1C or ANKS4B. Cells engineered to localize high levels of CDHR2 at filopodial tips acquired interfilopodial adhesion and exhibited a striking dynamic length-matching activity that aligned distal tips over time. These findings deepen our understanding of mechanisms that promote the distal tip accumulation of intermicrovillar adhesion complex components and also offer insight on how epithelial cells minimize microvillar length variability.
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Affiliation(s)
- Meredith L Weck
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Scott W Crawley
- Department of Biology, University of Toledo, Toledo, Ohio, USA
| | - Matthew J Tyska
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA.
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