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McGowan SE, Gilfanov N, Chandurkar MK, Stiber JA, Han SJ. Drebrin is Required for Myosin-facilitated Actin Cytoskeletal Remodeling during Pulmonary Alveolar Development. Am J Respir Cell Mol Biol 2024; 70:308-321. [PMID: 38271699 DOI: 10.1165/rcmb.2023-0229oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 01/25/2024] [Indexed: 01/27/2024] Open
Abstract
Alveolar septation increases gas-exchange surface area and requires coordinated cytoskeletal rearrangement in lung fibroblasts (LFs) to balance the demands of contraction and cell migration. We hypothesized that DBN (drebrin), a modulator of the actin cytoskeleton in neuronal dendrites, regulates the remodeling of the LF cytoskeleton. Using mice bearing a transgelin-Cre-targeted deletion of Dbn in pulmonary fibroblasts and pericytes, we examined alterations in alveolar septal outgrowth, LF spreading and migration, and actomyosin function. The alveolar surface area and number of alveoli were reduced, whereas alveolar ducts were enlarged, in mice bearing the dbn deletion (DBNΔ) compared with their littermates bearing only one dbn-Flox allele (control). Cultured DBNΔ LFs were deficient in their responses to substrate rigidity and migrated more slowly. Drebrin was abundant in the actin cortex and lamella, and the actin fiber orientation was less uniform in lamella of DBNΔ LFs, which limited the development of traction forces and altered focal adhesion dynamics. Actin fiber orientation is regulated by contractile NM2 (nonmuscle myosin-2) motors, which help arrange actin stress fibers into thick ventral actin stress fibers. Using fluorescence anisotropy, we observed regional intracellular differences in myosin regulatory light chain phosphorylation in control LFs that were altered by dbn deletion. Using perturbations to induce and then release stalling of NM2 on actin in LFs from both genotypes, we made predictions explaining how DBN interacts with actin and NM2. These studies provide new insight for diseases such as emphysema and pulmonary fibrosis, in which fibroblasts inappropriately respond to mechanical cues in their environment.
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Affiliation(s)
- Stephen E McGowan
- Department of Veterans Affairs Medical Center, Iowa City, Iowa
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | | | - Mohanish K Chandurkar
- Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan
| | - Jonathan A Stiber
- Department of Medicine, Duke University, Durham, North Carolina; and
| | - Sangyoon J Han
- Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan
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2
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Chandler T, Guo M, Su Y, Chen J, Wu Y, Liu J, Agashe A, Fischer RS, Mehta SB, Kumar A, Baskin TI, Jamouillé V, Liu H, Swaminathan V, Nain A, Oldenbourg R, Riviére PL, Shroff H. Three-dimensional spatio-angular fluorescence microscopy with a polarized dual-view inverted selective-plane illumination microscope (pol-diSPIM). bioRxiv 2024:2024.03.09.584243. [PMID: 38712306 PMCID: PMC11071302 DOI: 10.1101/2024.03.09.584243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Polarized fluorescence microscopy is a valuable tool for measuring molecular orientations, but techniques for recovering three-dimensional orientations and positions of fluorescent ensembles are limited. We report a polarized dual-view light-sheet system for determining the three-dimensional orientations and diffraction-limited positions of ensembles of fluorescent dipoles that label biological structures, and we share a set of visualization, histogram, and profiling tools for interpreting these positions and orientations. We model our samples, their excitation, and their detection using coarse-grained representations we call orientation distribution functions (ODFs). We apply ODFs to create physics-informed models of image formation with spatio-angular point-spread and transfer functions. We use theory and experiment to conclude that light-sheet tilting is a necessary part of our design for recovering all three-dimensional orientations. We use our system to extend known two-dimensional results to three dimensions in FM1-43-labelled giant unilamellar vesicles, fast-scarlet-labelled cellulose in xylem cells, and phalloidin-labelled actin in U2OS cells. Additionally, we observe phalloidin-labelled actin in mouse fibroblasts grown on grids of labelled nanowires and identify correlations between local actin alignment and global cell-scale orientation, indicating cellular coordination across length scales.
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Affiliation(s)
- Talon Chandler
- CZ Biohub SF, San Francisco, 94158, California, USA
- Department of Radiology, University of Chicago, Chicago, 60637, Illinois, USA
| | - Min Guo
- State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, 20892, Maryland, USA
| | - Yijun Su
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, 20892, Maryland, USA
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, 20892, Maryland, USA
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, 20147, Virginia, USA
| | - Jiji Chen
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, 20892, Maryland, USA
| | - Yicong Wu
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, 20892, Maryland, USA
| | - Junyu Liu
- State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
| | - Atharva Agashe
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, 24061, Virginia, USA
| | - Robert S. Fischer
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, 20892, Maryland, USA
| | - Shalin B. Mehta
- CZ Biohub SF, San Francisco, 94158, California, USA
- Department of Radiology, University of Chicago, Chicago, 60637, Illinois, USA
- Bell Center, Marine Biological Laboratory, Woods Hole, 02543, Massachusetts, USA
| | - Abhishek Kumar
- Bell Center, Marine Biological Laboratory, Woods Hole, 02543, Massachusetts, USA
| | - Tobias I. Baskin
- Biology Department, University of Massachusetts, Amherst, 01003, Maryland, USA
- Whitman Center, Marine Biological Laboratory, Woods Hole, 02543, Massachusetts, USA
| | - Valentin Jamouillé
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, 20892, Maryland, USA
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, V5A 1S6, British Columbia, Canada
| | - Huafeng Liu
- State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
| | - Vinay Swaminathan
- Department of Clinical Sciences, Lund University, Lund, SE-221 00, Scania, Sweden
- Wallenberg Centre for Molecular Medicine, Lund University, Lund, SE-221 00, Scania, Sweden
| | - Amrinder Nain
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, 24061, Virginia, USA
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, 24061, Virginia, USA
| | - Rudolf Oldenbourg
- Bell Center, Marine Biological Laboratory, Woods Hole, 02543, Massachusetts, USA
| | - Patrick La Riviére
- Department of Radiology, University of Chicago, Chicago, 60637, Illinois, USA
- Whitman Center, Marine Biological Laboratory, Woods Hole, 02543, Massachusetts, USA
| | - Hari Shroff
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, 20892, Maryland, USA
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, 20892, Maryland, USA
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, 20147, Virginia, USA
- Whitman Center, Marine Biological Laboratory, Woods Hole, 02543, Massachusetts, USA
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3
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Liu W, Liu YY, Zhang MQ, Qin MZ, Yang YY, Liu BW, Zhang DJ, Jiang CH, Yin ZQ, Lu M, Shen JP, Zhang J. A comparative study of the ameliorative effects of hyaluronic acid oligosaccharides and hyaluronic acid on DSS-induced colitis in mice and research on relevant mechanisms. Food Funct 2023. [PMID: 37366083 DOI: 10.1039/d2fo03644d] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
As a dietary supplement, hyaluronic acid (HA) has exhibited appreciable immunomodulatory activity and an ameliorative effect on rodent colitis. However, its high viscosity is not only refractory to absorb through the gut, but also causes flatulence. In contrast to HA, hyaluronic acid oligosaccharides (o-HAs) can overcome the above-mentioned constraints, but their treatment effect still remains ill-defined contemporarily. Herein, the current study intends to compare the modulatory effects of HA and o-HA on colitis and assess the underlying molecular mechanism. We first showed that o-HA had a better preventive effect than HA in alleviating colitis symptoms, as evidenced by lower body weight loss, lower disease activity index scores, a lower inflammatory response (TNF-α, IL-6, IL-1β, p-NF-κB), and more intact colon epithelial integrity in vivo. The best efficiency was observed in the o-HA treated group with a dosage of 30 mg kg-1. In an in vitro barrier function assay, o-HA exerted a better protective effect on the transepithelial electrical resistance (TEER), FITC permeability, and wound healing and modulated the expression of tight junction (TJ) proteins (ZO-1, occludin) in lipopolysaccharide (LPS)-stimulated Caco-2 cells. In summary, both HA and o-HA showed the potential to reduce inflammation and ameliorate intestinal damage in DSS-induced colitis and LPS-induced inflammation, but o-HA had improved outcomes. The results also provided a glimpse of the latent mechanism by which HA and o-HA enhanced intestinal barrier function via MLCK/p-MLC signaling pathway suppression.
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Affiliation(s)
- Wei Liu
- Department of Cardiology, Lishui District Hospital of Traditional Chinese Medicine, Nanjing 211200, China
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R. China.
| | - Yuan-Yuan Liu
- Department of Cardiology, Lishui District Hospital of Traditional Chinese Medicine, Nanjing 211200, China
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R. China.
| | - Meng-Qiu Zhang
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R. China.
| | - Miao-Zhen Qin
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R. China.
| | - Yuan-Yuan Yang
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R. China.
| | - Bi-Wen Liu
- Department of Cardiology, Lishui District Hospital of Traditional Chinese Medicine, Nanjing 211200, China
| | - Dong-Jian Zhang
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R. China.
| | - Cui-Hua Jiang
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R. China.
| | - Zhi-Qi Yin
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, Jiangsu Province, P.R. China
| | - Min Lu
- Department of Cardiology, Lishui District Hospital of Traditional Chinese Medicine, Nanjing 211200, China
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R. China.
| | - Jian-Ping Shen
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R. China.
| | - Jian Zhang
- Department of Cardiology, Lishui District Hospital of Traditional Chinese Medicine, Nanjing 211200, China
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R. China.
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4
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Zheng Y, Li X, Kuang L, Wang Y. New insights into the characteristics of DRAK2 and its role in apoptosis: From molecular mechanisms to clinically applied potential. Front Pharmacol 2022; 13:1014508. [PMID: 36386181 PMCID: PMC9649744 DOI: 10.3389/fphar.2022.1014508] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 10/12/2022] [Indexed: 11/27/2022] Open
Abstract
As a member of the death-associated protein kinase (DAPK) family, DAP kinase-associated apoptosis-inducing kinase 2 (DRAK2) performs apoptosis-related functions. Compelling evidence suggests that DRAK2 is involved in regulating the activation of T lymphocytes as well as pancreatic β-cell apoptosis in type I diabetes. In addition, DRAK2 has been shown to be involved in the development of related tumor and non-tumor diseases through a variety of mechanisms, including exacerbation of alcoholic fatty liver disease (NAFLD) through SRSF6-associated RNA selective splicing mechanism, regulation of chronic lymphocytic leukemia and acute myeloid leukemia, and progression of colorectal cancer. This review focuses on the structure, function, and upstream pathways of DRAK2 and discusses the potential and challenges associated with the clinical application of DRAK2-based small-molecule inhibitors, with the aim of advancing DRAK2 research.
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5
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Plante AE, Rao VP, Rizzo MA, Meredith AL. Comparative Ca 2+ channel contributions to intracellular Ca 2+ levels in the circadian clock. Biophys Rep (N Y) 2021; 1:100005. [PMID: 35330949 PMCID: PMC8942421 DOI: 10.1016/j.bpr.2021.100005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/08/2021] [Indexed: 11/22/2022]
Abstract
Circadian rhythms in mammals are coordinated by the central clock in the brain, located in the suprachiasmatic nucleus (SCN). Multiple molecular and cellular signals display a circadian variation within SCN neurons, including intracellular Ca2+, but the mechanisms are not definitively established. SCN cytosolic Ca2+ levels exhibit a peak during the day, when both action potential firing and Ca2+ channel activity are increased, and are decreased at night, correlating with a reduction in firing rate. In this study, we employ a single-color fluorescence anisotropy reporter (FLARE), Venus FLARE-Cameleon, and polarization inverted selective-plane illumination microscopy to measure rhythmic changes in cytosolic Ca2+ in SCN neurons. Using this technique, the Ca2+ channel subtypes contributing to intracellular Ca2+ at the peak and trough of the circadian cycle were assessed using a pharmacological approach with Ca2+ channel inhibitors. Peak (218 ± 16 nM) and trough (172 ± 13 nM) Ca2+ levels were quantified, indicating a 1.3-fold circadian variance in Ca2+ concentration. Inhibition of ryanodine-receptor-mediated Ca2+ release produced a larger relative decrease in cytosolic Ca2+ at both time points compared to voltage-gated Ca2+channels. These results support the hypothesis that circadian Ca2+ rhythms in SCN neurons are predominantly driven by intracellular Ca2+ channels, although not exclusively so. The study provides a foundation for future experiments to probe Ca2+ signaling in a dynamic biological context using FLAREs.
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Affiliation(s)
- Amber E. Plante
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Vishnu P. Rao
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Megan A. Rizzo
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Andrea L. Meredith
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
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6
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Abstract
Actin is a conserved cytoskeletal protein with essential functions. Here, we review the state-of-the-art reagents, tools and methods used to probe actin biology and functions in zebrafish embryo and larvae. We also discuss specific cell types and tissues where the study of actin in zebrafish has provided new insights into its functions.
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7
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Abstract
Blood and lymphatic vessels are lined by endothelial cells which constantly interact with their luminal and abluminal extracellular environments. These interactions confer physical forces on the endothelium, such as shear stress, stretch and stiffness, to mediate biological responses. These physical forces are often altered during disease, driving abnormal endothelial cell behavior and pathology. Therefore, it is critical that we understand the mechanisms by which endothelial cells respond to physical forces. Traditionally, endothelial cells in culture are grown in the absence of flow on stiff substrates such as plastic or glass. These cells are not subjected to the physical forces that endothelial cells endure in vivo, thus the results of these experiments often do not mimic those observed in the body. The field of vascular biology now realize that an intricate analysis of endothelial signaling mechanisms requires complex in vitro systems to mimic in vivo conditions. Here, we will review what is known about the mechanical forces that guide endothelial cell behavior and then discuss the advancements in endothelial cell culture models designed to better mimic the in vivo vascular microenvironment. A wider application of these technologies will provide more biologically relevant information from cultured cells which will be reproducible to conditions found in the body.
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Affiliation(s)
- Emma Gordon
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Lilian Schimmel
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Maike Frye
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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8
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Underhill SM, Colt MS, Amara SG. Amphetamine Stimulates Endocytosis of the Norepinephrine and Neuronal Glutamate Transporters in Cultured Locus Coeruleus Neurons. Neurochem Res 2020; 45:1410-9. [PMID: 31912366 DOI: 10.1007/s11064-019-02939-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/16/2019] [Accepted: 12/18/2019] [Indexed: 12/12/2022]
Abstract
Amphetamines and amphetamine-derivatives elevate neurotransmitter concentrations by competing with endogenous biogenic amines for reuptake. In addition, AMPHs have been shown to activate endocytosis of the dopamine transporter (DAT) which further elevates extracellular dopamine (DA). We previously found that the biochemical cascade leading to this cellular process involves entry of AMPH into the cell through the DAT, stimulation of an intracellular trace amine-associated receptor, TAAR1, and activation of the small GTPase, RhoA. We also showed that the neuronal glutamate transporter, EAAT3, undergoes endocytosis via the same cascade in DA neurons, leading to potentiation of glutamatergic inputs. Since AMPH is a transported inhibitor of both DAT and the norepinephrine transporter (NET), and EAAT3 is also expressed in norepinephrine (NE) neurons, we explored the possibility that this signaling cascade occurs in NE neurons. We found that AMPH can cause endocytosis of NET as well as EAAT3 in NE neurons. NET endocytosis is dependent on TAAR1, RhoA, intracellular calcium and CaMKII activation, similar to DAT. However, EAAT3 endocytosis is similar in all regards except its dependence upon CaMKII activation. RhoA activation is dependent on calcium, but not CaMKII, explaining a divergence in AMPH-mediated endocytosis of DAT and NET from that of EAAT3. These data indicate that AMPHs and other TAAR1 agonists can affect glutamate signaling through internalization of EAAT3 in NE as well as DA neurons.
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Barger SR, Gauthier NC, Krendel M. Squeezing in a Meal: Myosin Functions in Phagocytosis. Trends Cell Biol 2019; 30:157-167. [PMID: 31836280 DOI: 10.1016/j.tcb.2019.11.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/11/2019] [Accepted: 11/14/2019] [Indexed: 12/21/2022]
Abstract
Phagocytosis is a receptor-mediated, actin-dependent process of internalization of large extracellular particles, such as pathogens or apoptotic cells. Engulfment of phagocytic targets requires the activity of myosins, actin-dependent molecular motors, which perform a variety of functions at distinct steps during phagocytosis. By applying force to actin filaments, the plasma membrane, and intracellular proteins and organelles, myosins can generate contractility, directly regulate actin assembly to ensure proper phagocytic internalization, and translocate phagosomes or other cargo to appropriate cellular locations. Recent studies using engineered microenvironments and phagocytic targets have demonstrated how altering the actomyosin cytoskeleton affects phagocytic behavior. Here, we discuss how studies using genetic and biochemical manipulation of myosins, force measurement techniques, and live-cell imaging have advanced our understanding of how specific myosins function at individual steps of phagocytosis.
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Affiliation(s)
- Sarah R Barger
- Cell and Developmental Biology Department, State University of New York Upstate Medical University, Syracuse, NY, USA
| | | | - Mira Krendel
- Cell and Developmental Biology Department, State University of New York Upstate Medical University, Syracuse, NY, USA.
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10
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Jesorka A, Põldsalu I, Gözen I. Microfluidic technology for investigation of protein function in single adherent cells. Methods Enzymol 2019; 628:145-172. [PMID: 31668227 DOI: 10.1016/bs.mie.2019.07.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Instrumental techniques and associated methods for single cell analysis, designed to investigate and measure a broad range of cellular parameters in search of unique features, address key limitations of conventional cell-based assays with their ensemble average response. While many different single cell techniques exist for suspension cultures, which can process and characterize large numbers of individual cells in rapid succession, the access to surface-immobilized cells in typical 2D and 3D culture environments remains challenging. Open space microfluidics has created new possibilities in this area, allowing for exclusive access to single cells in adherent cultures, even at high confluency. In this chapter, we briefly review new microtechnologies for the investigation of protein function in single adherent cells, and present an overview over related recent applications of the multifunctional pipette (Biopen), a microfluidic multi-solution dispensing system that uses hydrodynamic confinement in open volume environments in order to establish a superfusion zone over selected single cells in adherent cultures.
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Affiliation(s)
- Aldo Jesorka
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, Sweden.
| | - Inga Põldsalu
- Centre for Molecular Medicine Norway, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Irep Gözen
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, Sweden; Centre for Molecular Medicine Norway, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway.
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11
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Samson SC, Elliott A, Mueller BD, Kim Y, Carney KR, Bergman JP, Blenis J, Mendoza MC. p90 ribosomal S6 kinase (RSK) phosphorylates myosin phosphatase and thereby controls edge dynamics during cell migration. J Biol Chem 2019; 294:10846-10862. [PMID: 31138649 PMCID: PMC6635457 DOI: 10.1074/jbc.ra119.007431] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 05/08/2019] [Indexed: 12/25/2022] Open
Abstract
Cell migration is essential to embryonic development, wound healing, and cancer cell dissemination. Cells move via leading-edge protrusion, substrate adhesion, and retraction of the cell's rear. The molecular mechanisms by which extracellular cues signal to the actomyosin cytoskeleton to control these motility mechanics are poorly understood. The growth factor-responsive and oncogenically activated protein extracellular signal-regulated kinase (ERK) promotes motility by signaling in actin polymerization-mediated edge protrusion. Using a combination of immunoblotting, co-immunoprecipitation, and myosin-binding experiments and cell migration assays, we show here that ERK also signals to the contractile machinery through its substrate, p90 ribosomal S6 kinase (RSK). We probed the signaling and migration dynamics of multiple mammalian cell lines and found that RSK phosphorylates myosin phosphatase–targeting subunit 1 (MYPT1) at Ser-507, which promotes an interaction of Rho kinase (ROCK) with MYPT1 and inhibits myosin targeting. We find that by inhibiting the myosin phosphatase, ERK and RSK promote myosin II–mediated tension for lamella expansion and optimal edge dynamics for cell migration. These findings suggest that ERK activity can coordinately amplify both protrusive and contractile forces for optimal cell motility.
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Affiliation(s)
- Shiela C Samson
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112 and
| | - Andrew Elliott
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112 and
| | - Brian D Mueller
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112 and
| | - Yung Kim
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112 and
| | - Keith R Carney
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112 and
| | - Jared P Bergman
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112 and
| | - John Blenis
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115
| | - Michelle C Mendoza
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112 and; Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115.
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12
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Abstract
FRET-based genetically encoded biosensors incorporate two fluorescent proteins into their design to enable ratiometric biosensing of signaling activities in live cells. While emission ratios are generally useful for quantitative studies, they leave little room in the optical spectrum for additional sensors and optogenetic tools. Homotransfer-based reporters, such as the FLuorescence Anisotropy REporters (FLAREs), incorporate two fluorescent proteins of the same color into their design. Conversion to a single color opens the visible spectrum for the use of complementary sensors. Here, we present a protocol for measuring three independent intracellular signals in living cells. We describe the configuration and calibration of a widefield microscope for multicolor FLARE imaging. Three FLARE sensors for intracellular calcium, MAPK activity, and PKA phosphorylation are co-transfected into HEK293 cells, and triple FRET imaging is performed. Compared to heterotransfer FRET biosensors, the polarization-based multiplex imaging can track multiple signaling activities concurrently in a targeted cell population.
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Affiliation(s)
- Brian Ross
- Department of Pharmacology, University of California, San Diego, La Jolla, California, United States.,Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, Maryland, United States
| | - Shenq Huey Wong
- Department of Physiology, University of Maryland Baltimore, Maryland, United States
| | - Nicole E Snell
- Department of Physiology, University of Maryland Baltimore, Maryland, United States
| | - Jin Zhang
- Department of Pharmacology, University of California, San Diego, La Jolla, California, United States.,Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - M A Rizzo
- Department of Physiology, University of Maryland Baltimore, Maryland, United States
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13
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Snell NE, Rao VP, Seckinger KM, Liang J, Leser J, Mancini AE, Rizzo MA. Homotransfer of FRET Reporters for Live Cell Imaging. Biosensors (Basel) 2018; 8:bios8040089. [PMID: 30314323 PMCID: PMC6316388 DOI: 10.3390/bios8040089] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 09/27/2018] [Accepted: 10/10/2018] [Indexed: 01/01/2023]
Abstract
Förster resonance energy transfer (FRET) between fluorophores of the same species was recognized in the early to mid-1900s, well before modern heterotransfer applications. Recently, homotransfer FRET principles have re-emerged in biosensors that incorporate genetically encoded fluorescent proteins. Homotransfer offers distinct advantages over the standard heterotransfer FRET method, some of which are related to the use of fluorescence polarization microscopy to quantify FRET between two fluorophores of identical color. These include enhanced signal-to-noise, greater compatibility with other optical sensors and modulators, and new design strategies based upon the clustering or dimerization of singly-labeled sensors. Here, we discuss the theoretical basis for measuring homotransfer using polarization microscopy, procedures for data collection and processing, and we review the existing genetically-encoded homotransfer biosensors.
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Affiliation(s)
- Nicole E Snell
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
| | - Vishnu P Rao
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
| | - Kendra M Seckinger
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
| | - Junyi Liang
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
| | - Jenna Leser
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
| | - Allison E Mancini
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
| | - M A Rizzo
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
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Seckinger KM, Rao VP, Snell NE, Mancini AE, Markwardt ML, Rizzo MA. Nitric Oxide Activates β-Cell Glucokinase by Promoting Formation of the "Glucose-Activated" State. Biochemistry 2018; 57:5136-5144. [PMID: 30053375 DOI: 10.1021/acs.biochem.8b00333] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The release of insulin from the pancreas is tightly controlled by glucokinase (GCK) activity that couples β-cell metabolism to changes in blood sugar. Despite having only a single glucose-binding site, GCK displays positive glucose cooperativity. Ex vivo structural studies have identified several potential protein conformations with varying levels of enzymatic activity, yet it is unclear how living cells regulate GCK cooperativity. To better understand the cellular regulation of GCK activation, we developed a homotransfer Förster resonance energy transfer (FRET) GCK biosensor and used polarization microscopy to eliminate fluorescence crosstalk from FRET quantification and improve the signal-to-noise ratio. This approach enhanced sensor contrast compared to that seen with the heterotransfer FRET GCK reporter and allowed observation of individual GCK states using an automated method to analyze FRET data at the pixel level. Mutations known to activate and inhibit GCK activity produced distinct anisotropy distributions, suggesting that at least two conformational states exist in living cells. A high glucose level activated the biosensor in a manner consistent with GCK's enzymology. Interestingly, glucose-free conditions did not affect GCK biosensor FRET, indicating that there is a single low-activity state, which is counter to proposed structural models of GCK cooperativity. Under low-glucose conditions, application of chemical NO donors efficiently shifted GCK to the more active conformation. Notably, GCK activation by mutation, a high glucose level, a pharmacological GCK activator, or S-nitrosylation all shared the same FRET distribution. These data suggest a simplified model for GCK activation in living cells, where post-translational modification of GCK by S-nitrosylation facilitates a single conformational transition that enhances GCK enzymatic activity.
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Affiliation(s)
- Kendra M Seckinger
- Department of Physiology , University of Maryland School of Medicine , Baltimore , Maryland 21201 , United States
| | - Vishnu P Rao
- Department of Physiology , University of Maryland School of Medicine , Baltimore , Maryland 21201 , United States
| | - Nicole E Snell
- Department of Physiology , University of Maryland School of Medicine , Baltimore , Maryland 21201 , United States
| | - Allison E Mancini
- Department of Physiology , University of Maryland School of Medicine , Baltimore , Maryland 21201 , United States
| | - Michele L Markwardt
- Department of Physiology , University of Maryland School of Medicine , Baltimore , Maryland 21201 , United States
| | - M A Rizzo
- Department of Physiology , University of Maryland School of Medicine , Baltimore , Maryland 21201 , United States
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