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Ono S, Watabe E, Morisaki K, Ono K, Kuroyanagi H. Alternative splicing of a single exon causes a major impact on the affinity of Caenorhabditis elegans tropomyosin isoforms for actin filaments. Front Cell Dev Biol 2023; 11:1208913. [PMID: 37745299 PMCID: PMC10512467 DOI: 10.3389/fcell.2023.1208913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 08/29/2023] [Indexed: 09/26/2023] Open
Abstract
Tropomyosin is generally known as an actin-binding protein that regulates actomyosin interaction and actin filament stability. In metazoans, multiple tropomyosin isoforms are expressed, and some of them are involved in generating subpopulations of actin cytoskeleton in an isoform-specific manner. However, functions of many tropomyosin isoforms remain unknown. Here, we report identification of a novel alternative exon in the Caenorhabditis elegans tropomyosin gene and characterization of the effects of alternative splicing on the properties of tropomyosin isoforms. Previous studies have reported six tropomyosin isoforms encoded by the C. elegans lev-11 tropomyosin gene. We identified a seventh isoform, LEV-11U, that contained a novel alternative exon, exon 7c (E7c). LEV-11U is a low-molecular-weight tropomyosin isoform that differs from LEV-11T only at the exon 7-encoded region. In silico analyses indicated that the E7c-encoded peptide sequence was unfavorable for coiled-coil formation and distinct from other tropomyosin isoforms in the pattern of electrostatic surface potentials. In vitro, LEV-11U bound poorly to actin filaments, whereas LEV-11T bound to actin filaments in a saturable manner. When these isoforms were transgenically expressed in the C. elegans striated muscle, LEV-11U was present in the diffuse cytoplasm with tendency to form aggregates, whereas LEV-11T co-localized with sarcomeric actin filaments. Worms with a mutation in E7c showed reduced motility and brood size, suggesting that this exon is important for the optimal health. These results indicate that alternative splicing of a single exon can produce biochemically diverged tropomyosin isoforms and suggest that a tropomyosin isoform with poor actin affinity has a novel biological function.
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Affiliation(s)
- Shoichiro Ono
- Departments of Pathology and Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, United States
| | - Eichi Watabe
- Laboratory of Gene Expression, Graduate School of Biomedical Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Keita Morisaki
- Departments of Pathology and Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Kanako Ono
- Departments of Pathology and Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, United States
| | - Hidehito Kuroyanagi
- Laboratory of Gene Expression, Graduate School of Biomedical Sciences, Tokyo Medical and Dental University, Tokyo, Japan
- Department of Biochemistry, University of the Ryukyus Graduate School of Medicine, Okinawa, Japan
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Ono S, Lewis M, Ono K. Mutual dependence between tropomodulin and tropomyosin in the regulation of sarcomeric actin assembly in Caenorhabditis elegans striated muscle. Eur J Cell Biol 2022; 101:151215. [PMID: 35306452 PMCID: PMC9081161 DOI: 10.1016/j.ejcb.2022.151215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 02/24/2022] [Accepted: 03/14/2022] [Indexed: 11/25/2022] Open
Abstract
Tropomodulin and tropomyosin are important components of sarcomeric thin filaments in striated muscles. Tropomyosin decorates the side of actin filaments and enhances tropomodulin capping at the pointed ends of the filaments. Their functional relationship has been extensively characterized in vitro, but in vivo and cellular studies in mammals are often complicated by the presence of functionally redundant isoforms. Here, we used the nematode Caenorhabditis elegans, which has a relatively simple composition of tropomodulin and tropomyosin genes, and demonstrated that tropomodulin (unc-94) and tropomyosin (lev-11) are mutually dependent on each other in their sarcomere localization and regulation of sarcomeric actin assembly. Mutation of tropomodulin caused sarcomere disorganization with formation of actin aggregates. However, the actin aggregation was suppressed when tropomyosin was depleted in the tropomodulin mutant. Tropomyosin was mislocalized to the actin aggregates in the tropomodulin mutants, while sarcomere localization of tropomodulin was lost when tropomyosin was depleted. These results indicate that tropomodulin and tropomyosin are interdependent in the regulation of organized sarcomeric assembly of actin filaments in vivo.
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Affiliation(s)
- Shoichiro Ono
- Departments of Pathology and Cell Biology, Emory University School of Medicine, Atlanta, GA, USA; Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, USA.
| | - Mario Lewis
- Departments of Pathology and Cell Biology, Emory University School of Medicine, Atlanta, GA, USA; Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, USA
| | - Kanako Ono
- Departments of Pathology and Cell Biology, Emory University School of Medicine, Atlanta, GA, USA; Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, USA
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3
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Imaging of Actin Cytoskeleton in the Nematode Caenorhabditis elegans. Methods Mol Biol 2021. [PMID: 34542852 DOI: 10.1007/978-1-0716-1661-1_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
The nematode Caenorhabditis elegans is one of the major model organisms in cell and developmental biology. This organism is easy to culture in laboratories and suitable for microscopic investigation of the cytoskeleton. Because the worms are small and transparent, the actin cytoskeleton in many tissues and cells can be observed with appropriate visualization techniques without sectioning or dissection. This chapter describes the introduction to representative methods for imaging the actin cytoskeleton in C. elegans and a protocol for staining worms with fluorescent phalloidin.
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Lesanpezeshki L, Qadota H, Darabad MN, Kashyap K, Lacerda CMR, Szewczyk NJ, Benian GM, Vanapalli SA. Investigating the correlation of muscle function tests and sarcomere organization in C. elegans. Skelet Muscle 2021; 11:20. [PMID: 34389048 PMCID: PMC8362255 DOI: 10.1186/s13395-021-00275-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 07/08/2021] [Indexed: 11/20/2022] Open
Abstract
Background Caenorhabditis elegans has been widely used as a model to study muscle structure and function. Its body wall muscle is functionally and structurally similar to vertebrate skeletal muscle with conserved molecular pathways contributing to sarcomere structure, and muscle function. However, a systematic investigation of the relationship between muscle force and sarcomere organization is lacking. Here, we investigate the contribution of various sarcomere proteins and membrane attachment components to muscle structure and function to introduce C. elegans as a model organism to study the genetic basis of muscle strength. Methods We employ two recently developed assays that involve exertion of muscle forces to investigate the correlation of muscle function to sarcomere organization. We utilized a microfluidic pillar-based platform called NemaFlex that quantifies the maximum exertable force and a burrowing assay that challenges the animals to move in three dimensions under a chemical stimulus. We selected 20 mutants with known defects in various substructures of sarcomeres and compared the physiological function of muscle proteins required for force generation and transmission. We also characterized the degree of sarcomere disorganization using immunostaining approaches. Results We find that mutants with genetic defects in thin filaments, thick filaments, and M-lines are generally weaker, and our assays are successful in detecting the functional changes in response to each sarcomere location tested. We find that the NemaFlex and burrowing assays are functionally distinct informing on different aspects of muscle physiology. Specifically, the burrowing assay has a larger bandwidth in phenotyping muscle mutants, because it could pick ten additional mutants impaired while exerting normal muscle force in NemaFlex. This enabled us to combine their readouts to develop an integrated muscle function score that was found to correlate with the score for muscle structure disorganization. Conclusions Our results highlight the suitability of NemaFlex and burrowing assays for evaluating muscle physiology of C. elegans. Using these approaches, we discuss the importance of the studied sarcomere proteins for muscle function and structure. The scoring methodology we have developed enhances the utility of C. elegans as a genetic model to study muscle function. Supplementary Information The online version contains supplementary material available at 10.1186/s13395-021-00275-4.
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Affiliation(s)
- Leila Lesanpezeshki
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX, 79409, USA
| | - Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, GA, 30322, USA
| | | | - Karishma Kashyap
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Carla M R Lacerda
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX, 79409, USA
| | - Nathaniel J Szewczyk
- MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Nottingham, United Kingdom & National Institute for Health Research Nottingham Biomedical Research Centre, Derby, DE22 3DT, UK.,Ohio Musculoskeletal and Neurological Institute (OMNI) and Department of Biomedical Sciences, Ohio University, Athens, OH, 45701, USA
| | - Guy M Benian
- Department of Pathology, Emory University, Atlanta, GA, 30322, USA
| | - Siva A Vanapalli
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX, 79409, USA.
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Kashyap SS, Verma S, McHugh M, Wolday M, Williams PD, Robertson AP, Martin RJ. Anthelmintic resistance and homeostatic plasticity (Brugia malayi). Sci Rep 2021; 11:14499. [PMID: 34262123 PMCID: PMC8280109 DOI: 10.1038/s41598-021-93911-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 07/01/2021] [Indexed: 11/18/2022] Open
Abstract
Homeostatic plasticity refers to the capacity of excitable cells to regulate their activity to make compensatory adjustments to long-lasting stimulation. It is found across the spectrum of vertebrate and invertebrate species and is driven by changes in cytosolic calcium; it has not been explored in parasitic nematodes when treated with therapeutic drugs. Here we have studied the adaptation of Brugia malayi to exposure to the anthelmintic, levamisole that activates muscle AChR ion-channels. We found three phases of the Brugia malayi motility responses as they adapted to levamisole: an initial spastic paralysis; a flaccid paralysis that follows; and finally, a recovery of motility with loss of sensitivity to levamisole at 4 h. Motility, calcium-imaging, patch-clamp and molecular experiments showed the muscle AChRs are dynamic with mechanisms that adjust their subtype composition and sensitivity to levamisole. This homeostatic plasticity allows the parasite to adapt resisting the anthelmintic.
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Affiliation(s)
- Sudhanva S Kashyap
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Saurabh Verma
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Mark McHugh
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Mengisteab Wolday
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Paul D Williams
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Alan P Robertson
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Richard J Martin
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA.
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Youssef K, Archonta D, Kubiseski TJ, Tandon A, Rezai P. Electric egg-laying: a new approach for regulating C. elegans egg-laying behaviour in a microchannel using electric field. LAB ON A CHIP 2021; 21:821-834. [PMID: 33527103 DOI: 10.1039/d0lc00964d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In this paper, the novel effect of electric field (EF) on adult C. elegans egg-laying in a microchannel is discovered and correlated with neural and muscular activities. The quantitative effects of worm aging and EF strength, direction, and exposure duration on egg-laying are studied phenotypically using egg-count, body length, head movement, and transient neuronal activity readouts. Electric egg-laying rate increases significantly when worms face the anode and the response is EF-dependent, i.e. stronger (6 V cm-1) and longer EF (40 s) exposure result in a shorter egg laying response duration. Worm aging significantly deteriorates the electric egg-laying behaviour with an 88% decrease in the egg-count from day-1 to day-4 post young-adult stage. Fluorescent imaging of intracellular calcium dynamics in the main parts of the egg-laying neural circuit demonstrates the involvement and sensitivity of the serotonergic hermaphrodite specific neurons (HSNs), vulva muscles, and ventral cord neurons to the EF. HSN mutation also results in a reduced rate of electric egg-laying allowing the use of this technique for cellular screening and mapping of the neural basis of electrosensation in C. elegans. This novel assay can be parallelized and performed in a high-throughput manner for drug and gene screening applications.
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Affiliation(s)
- Khaled Youssef
- Department of Mechanical Engineering, York University, Toronto, ON, Canada.
| | - Daphne Archonta
- Department of Mechanical Engineering, York University, Toronto, ON, Canada.
| | | | - Anurag Tandon
- Tanz Centre for Research in Neurodegenerative Diseases, Toronto, Ontario, Canada and Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Pouya Rezai
- Department of Mechanical Engineering, York University, Toronto, ON, Canada.
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Ge A, Hu L, Fan J, Ge M, Wang X, Wang S, Feng X, Du W, Liu BF. A low-cost microfluidic platform coupled with light emitting diode for optogenetic analysis of neuronal response in C. elegans. Talanta 2021; 223:121646. [PMID: 33303134 DOI: 10.1016/j.talanta.2020.121646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/02/2020] [Accepted: 09/06/2020] [Indexed: 11/24/2022]
Abstract
Optogenetic method is widely used for dissecting the neuronal function and connectivity in a specific neural circuit, which can help understanding how the animal process information and generate behavior. The nematode C. elegans has a simple but complete nervous system, making it an attractive model to study the dynamics signals of neural circuits. However, in vivo analysis on neural circuits usually rely on the complex and expensive optical equipment to allow optogenetic stimulating the neuron while recording its activities in such a freely moving animal. Hence, in this paper we reported a portable optofluidic platform that works based on optical fiber illumination and functional imaging for worm optogenetic manipulation. A light beam from LED laser pen crossing the 3D-printed optical fiber channel is used to activate the neurons specific-expressed with light sensitive proteins ChR-2. The imaging light path is perpendicular to the stimulation light, which allows activating neuron precisely and measuring cellular signals simultaneously. By using such an easy-to-assemble device, optical stimulation of the specific neurons and detection of dynamic calcium responses of other neurons could be proceeded simultaneously. Thus, the developed microfluidic platform puts forward a simple, rapid and low-cost strategy for further neural circuits studies.
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Affiliation(s)
- Anle Ge
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China; Single Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
| | - Liang Hu
- School of Ophthalmology & Optometry, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - JiaXing Fan
- Department of Urology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, China
| | - Minghai Ge
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Xixian Wang
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China; Single Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
| | - Shanshan Wang
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Xiaojun Feng
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Wei Du
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Bi-Feng Liu
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
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Immunolocalization of Disorganized Muscle Protein-1 in Different Life Stages of Human Lymphatic Filariid, Brugia malayi. Acta Parasitol 2020; 65:990-994. [PMID: 32500507 PMCID: PMC7271955 DOI: 10.2478/s11686-020-00225-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 05/02/2020] [Indexed: 12/22/2022]
Abstract
Purpose We recently identified disorganized muscle protein-1 of Brugia malayi (DIM-1bm) as a vaccine candidate for human lymphatic filariasis. The present study was aimed at investigating the localization of DIM-1bm in the life-stages of B. malayi to identify the tissue target of vaccine action. Methods Recombinant DIM-1bm (rDIM-1bm) was prepared and antibodies were raised in BALB/c mice. Immunoblots of SDS-PAGE resolved B. malayi infective 3rd stage larvae (L3) and adult worm antigens and rDIM-1bm were prepared and reacted with anti-rDIM-1bm sera. Sections of adult female worms and whole-mount preparations of L3 and microfilariae (mf) were stained by immunofluorescence using rDIM-1bm antibodies and Alexa Fluor 488 labeled secondary antibodies, and examined under a confocal microscope. Results Immunofluorescence staining showed that DIM-1bm is localized mainly in the subcuticular muscle layer in the L3 and the adult worms; no fluorescent signal could be detected in mf. Conclusion The localization of DIM-1bm in the parasites’ muscle layer suggests that the immunoprophylactic efficacy of DIM-1 is evidently due to immobilization of the parasite and its subsequent immune elimination.
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Abstract
In the last decade, microfluidic methods have proven to be powerful tools for Caenorhabditis elegans research, offering advanced manipulation of worms and precise control of experimental conditions. The advantages of microfluidic chips include their capability of immobilization, automated sorting, and longitudinal measurement, and more. In this review, we focus on control components that are widely used in the design of microfluidic devices, and discuss their functions and working principles that enable advanced manipulation on a chip. Understanding these components will ease the onboarding of researchers inexperienced with microfluidics and help them bring the power of microfluidics to new applications.
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Affiliation(s)
- Erel Levine
- Department of Bioengineering, Northeastern University, Boston, MA, USA
| | - Kyung Suk Lee
- Department of Physics Education, Kongju National University, Gongju, South Korea
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Modelling Neuromuscular Diseases in the Age of Precision Medicine. J Pers Med 2020; 10:jpm10040178. [PMID: 33080928 PMCID: PMC7712305 DOI: 10.3390/jpm10040178] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/14/2020] [Accepted: 10/15/2020] [Indexed: 12/20/2022] Open
Abstract
Advances in knowledge resulting from the sequencing of the human genome, coupled with technological developments and a deeper understanding of disease mechanisms of pathogenesis are paving the way for a growing role of precision medicine in the treatment of a number of human conditions. The goal of precision medicine is to identify and deliver effective therapeutic approaches based on patients’ genetic, environmental, and lifestyle factors. With the exception of cancer, neurological diseases provide the most promising opportunity to achieve treatment personalisation, mainly because of accelerated progress in gene discovery, deep clinical phenotyping, and biomarker availability. Developing reproducible, predictable and reliable disease models will be key to the rapid delivery of the anticipated benefits of precision medicine. Here we summarize the current state of the art of preclinical models for neuromuscular diseases, with particular focus on their use and limitations to predict safety and efficacy treatment outcomes in clinical trials.
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Viri V, Cornaglia M, Atakan HB, Lehnert T, Gijs MAM. An in vivo microfluidic study of bacterial transit in C. elegans nematodes. LAB ON A CHIP 2020; 20:2696-2708. [PMID: 32633746 DOI: 10.1039/d0lc00064g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Caenorhabditis elegans (C. elegans) constitutes an important model organism for use in nutrition and aging studies. We report a novel method for studying the dynamics of Escherichia coli (E. coli) bacterial transit through the worms' intestine. A microfluidic chip was designed for alternating C. elegans on-chip culture and immobilization, thereby enabling periodic high-resolution time-lapse imaging at single-worm resolution over several days. Immobilization was achieved in a reversible way using arrays of tapered channels suitable for assay parallelization. Dedicated C. elegans feeding protocols were applied. Two E. coli bacterial strains, HT115 and OP50, respectively labeled with green fluorescent protein (GFP) and red fluorescent protein (RFP), were used as food source and imaged with fluorescence microscopy techniques to measure relevant parameters of the bacterial transit process. Feeding behavior and E. coli transit dynamics in the whole intestinal tract of the worms were characterized in an automated way over the first 3 days of adulthood, revealing both fast transit phenomena and variations in microbial accumulation. In particular, we studied the bacterial food transit periodicity in wild-type and eat-2 (ad465) mutant C. elegans strains in both trapped and free-swimming conditions. In order to further demonstrate the versatility of our microfluidic platform, we also studied drug-induced modifications of the bacterial transit by measuring the response of the worms' intestine to exposure to the neurotransmitter serotonin.
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Affiliation(s)
- Vittorio Viri
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
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12
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Zhao Y, Demirci U, Chen Y, Chen P. Multiscale brain research on a microfluidic chip. LAB ON A CHIP 2020; 20:1531-1543. [PMID: 32150176 DOI: 10.1039/c9lc01010f] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
One major challenge in current brain research is generating an integrative understanding of the brain's functions and disorders from its multiscale neuronal architectures and connectivity. Thus, innovative neurotechnology tools are urgently required for deciphering the multiscale functional and structural organizations of the brain at hierarchical scales from the molecular to the organismal level by multiple brain research initiatives launched by the European Union, United States, Australia, Canada, China, Korea, and Japan. To meet this demand, microfluidic chips (μFCs) have rapidly evolved as a trans-scale neurotechnological toolset to enable multiscale studies of the brain due to their unique advantages in flexible microstructure design, multifunctional integration, accurate microenvironment control, and capacity for automatic sample processing. Here, we review the recent progress in applying innovative μFC-based neuro-technologies to promote multiscale brain research and uniquely focus on representative applications of μFCs to address challenges in brain research at each hierarchical level. We discuss the current trend of combinational applications of μFCs with other neuro- and biotechnologies, including optogenetics, brain organoids, and 3D bioprinting, for better multiscale brain research. In addition, we offer our insights into the existing outstanding questions at each hierarchical level of brain research that could potentially be addressed by advancing microfluidic techniques. This review will serve as a timely guide for bioengineers and neuroscientists to develop and apply μFC-based neuro-technologies for promoting basic and translational brain research.
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Affiliation(s)
- Yanan Zhao
- Department of Biomedical Engineering, Wuhan University School of Basic Medical Sciences, 115 Donghu Road, Wuhan 430071, China.
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Holmes JB, Doh CY, Mamidi R, Li J, Stelzer JE. Strategies for targeting the cardiac sarcomere: avenues for novel drug discovery. Expert Opin Drug Discov 2020; 15:457-469. [PMID: 32067508 PMCID: PMC7065952 DOI: 10.1080/17460441.2020.1722637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 01/24/2020] [Indexed: 01/10/2023]
Abstract
Introduction: Heart failure remains one of the largest clinical challenges in the United States. Researchers have continually searched for more effective heart failure treatments that target the cardiac sarcomere but have found few successes despite numerous expensive cardiovascular clinical trials. Among many reasons, the high failure rate of cardiovascular clinical trials may be partly due to incomplete characterization of a drug candidate's complex interaction with cardiac physiology.Areas covered: In this review, the authors address the issue of preclinical cardiovascular studies of sarcomere-targeting heart failure therapies. The authors consider inherent tradeoffs made between mechanistic transparency and physiological fidelity for several relevant preclinical techniques at the atomic, molecular, heart muscle fiber, whole heart, and whole-organism levels. Thus, the authors suggest a comprehensive, bottom-up approach to preclinical cardiovascular studies that fosters scientific rigor and hypothesis-driven drug discovery.Expert opinion: In the authors' opinion, the implementation of hypothesis-driven drug discovery practices, such as the bottom-up approach to preclinical cardiovascular studies, will be imperative for the successful development of novel heart failure treatments. However, additional changes to clinical definitions of heart failure and current drug discovery culture must accompany the bottom-up approach to maximize the effectiveness of hypothesis-driven drug discovery.
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Affiliation(s)
- Joshua B Holmes
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Chang Yoon Doh
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Ranganath Mamidi
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Jiayang Li
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Julian E Stelzer
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
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Midkiff D, San-Miguel A. Microfluidic Technologies for High Throughput Screening Through Sorting and On-Chip Culture of C. elegans. Molecules 2019; 24:molecules24234292. [PMID: 31775328 PMCID: PMC6930626 DOI: 10.3390/molecules24234292] [Citation(s) in RCA: 20] [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: 11/02/2019] [Revised: 11/20/2019] [Accepted: 11/22/2019] [Indexed: 02/07/2023] Open
Abstract
The nematode Caenorhabditis elegans is a powerful model organism that has been widely used to study molecular biology, cell development, neurobiology, and aging. Despite their use for the past several decades, the conventional techniques for growth, imaging, and behavioral analysis of C. elegans can be cumbersome, and acquiring large data sets in a high-throughput manner can be challenging. Developments in microfluidic “lab-on-a-chip” technologies have improved studies of C. elegans by increasing experimental control and throughput. Microfluidic features such as on-chip control layers, immobilization channels, and chamber arrays have been incorporated to develop increasingly complex platforms that make experimental techniques more powerful. Genetic and chemical screens are performed on C. elegans to determine gene function and phenotypic outcomes of perturbations, to test the effect that chemicals have on health and behavior, and to find drug candidates. In this review, we will discuss microfluidic technologies that have been used to increase the throughput of genetic and chemical screens in C. elegans. We will discuss screens for neurobiology, aging, development, behavior, and many other biological processes. We will also discuss robotic technologies that assist in microfluidic screens, as well as alternate platforms that perform functions similar to microfluidics.
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15
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Osório DS, Chan FY, Saramago J, Leite J, Silva AM, Sobral AF, Gassmann R, Carvalho AX. Crosslinking activity of non-muscle myosin II is not sufficient for embryonic cytokinesis in C. elegans. Development 2019; 146:dev.179150. [PMID: 31582415 PMCID: PMC6857588 DOI: 10.1242/dev.179150] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 09/23/2019] [Indexed: 11/21/2022]
Abstract
Cytokinesis in animal cells requires the assembly and constriction of a contractile actomyosin ring. Non-muscle myosin II is essential for cytokinesis, but the role of its motor activity remains unclear. Here, we examine cytokinesis in C. elegans embryos expressing non-muscle myosin motor mutants generated by genome editing. Two non-muscle motor-dead myosins capable of binding F-actin do not support cytokinesis in the one-cell embryo, and two partially motor-impaired myosins delay cytokinesis and render rings more sensitive to reduced myosin levels. Further analysis of myosin mutants suggests that it is myosin motor activity, and not the ability of myosin to crosslink F-actin, that drives the alignment and compaction of F-actin bundles during contractile ring assembly, and that myosin motor activity sets the pace of contractile ring constriction. We conclude that myosin motor activity is required at all stages of cytokinesis. Finally, characterization of the corresponding motor mutations in C. elegans major muscle myosin shows that motor activity is required for muscle contraction but is dispensable for F-actin organization in adult muscles. This article has an associated ‘The people behind the papers’ interview. Highlighted Article: The motor activity of non-muscle myosin II is essential for cytokinesis and contributes to all stages of the process in C. elegans embryos.
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Affiliation(s)
- Daniel S Osório
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal .,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Fung-Yi Chan
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Joana Saramago
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Joana Leite
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana M Silva
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana F Sobral
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Reto Gassmann
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana Xavier Carvalho
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal .,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
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16
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Watabe E, Ono S, Kuroyanagi H. Alternative splicing of the Caenorhabditis elegans lev-11 tropomyosin gene is regulated in a tissue-specific manner. Cytoskeleton (Hoboken) 2018; 75:427-436. [PMID: 30155988 DOI: 10.1002/cm.21489] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 08/02/2018] [Accepted: 08/22/2018] [Indexed: 01/14/2023]
Abstract
Tropomyosin isoforms contribute to generation of functionally divergent actin filaments. In the nematode Caenorhabditis elegans, multiple isoforms are produced from lev-11, the single tropomyosin gene, by combination of two separate promoters and alternative pre-mRNA splicing. In this study, we report that alternative splicing of lev-11 is regulated in a tissue-specific manner so that a particular tropomyosin isoform is expressed in each tissue. Reverse-transcription polymerase chain reaction analysis of lev-11 mRNAs confirms five previously reported isoforms (LEV-11A, LEV-11C, LEV-11D, LEV-11E and LEV-11O) and identifies a new sixth isoform LEV-11T. Using transgenic alternative-splicing reporter minigenes, we find distinct patterns of preferential exon selections in the pharynx, body wall muscles, intestine and neurons. The body wall muscles preferentially process splicing to produce high-molecular-weight isoforms, LEV-11A, LEV-11D and LEV-11O. The pharynx specifically processes splicing to express a low-molecular-weight isoform LEV-11E, whereas the intestine and neurons process splicing to express another low-molecular-weight isoform LEV-11C. The splicing pattern of LEV-11T was not predominant in any of these tissues, suggesting that this is a minor isoform. Our results suggest that regulation of alternative splicing is an important mechanism to express proper tropomyosin isoforms in particular tissue and/or cell types in C. elegans.
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Affiliation(s)
- Eichi Watabe
- Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shoichiro Ono
- Department of Pathology, Department of Cell Biology, and Winship Cancer Institute, Emory University, Atlanta, Georgia
| | - Hidehito Kuroyanagi
- Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
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17
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Rahman M, Hewitt JE, Van-Bussel F, Edwards H, Blawzdziewicz J, Szewczyk NJ, Driscoll M, Vanapalli SA. NemaFlex: a microfluidics-based technology for standardized measurement of muscular strength of C. elegans. LAB ON A CHIP 2018; 18:2187-2201. [PMID: 29892747 PMCID: PMC6057834 DOI: 10.1039/c8lc00103k] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Muscle strength is a functional measure of quality of life in humans. Declines in muscle strength are manifested in diseases as well as during inactivity, aging, and space travel. With conserved muscle biology, the simple genetic model C. elegans is a high throughput platform in which to identify molecular mechanisms causing muscle strength loss and to develop interventions based on diet, exercise, and drugs. In the clinic, standardized strength measures are essential to quantitate changes in patients; however, analogous standards have not been recapitulated in the C. elegans model since force generation fluctuates based on animal behavior and locomotion. Here, we report a microfluidics-based system for strength measurement that we call 'NemaFlex', based on pillar deflection as the nematode crawls through a forest of pillars. We have optimized the micropillar forest design and identified robust measurement conditions that yield a measure of strength that is independent of behavior and gait. Validation studies using a muscle contracting agent and mutants confirm that NemaFlex can reliably score muscular strength in C. elegans. Additionally, we report a scaling factor to account for animal size that is consistent with a biomechanics model and enables comparative strength studies of mutants. Taken together, our findings anchor NemaFlex for applications in genetic and drug screens, for defining molecular and cellular circuits of neuromuscular function, and for dissection of degenerative processes in disuse, aging, and disease.
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Affiliation(s)
- Mizanur Rahman
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, USA.
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18
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Kamili F, Lu H. Recent Advances and Trends in Microfluidic Platforms for C. elegans Biological Assays. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2018; 11:245-264. [PMID: 29894230 DOI: 10.1146/annurev-anchem-061417-125604] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Microfluidics has proven to be a key tool in quantitative biological research. The C. elegans research community in particular has developed a variety of microfluidic platforms to investigate sensory systems, development, aging, and physiology of the nematode. Critical for the growth of this field, however, has been the implementation of concurrent advanced microscopy, hardware, and software technologies that enable the discovery of novel biology. In this review, we highlight recent innovations in microfluidic platforms used for assaying C. elegans and discuss the novel technological approaches and analytic strategies required for these systems. We conclude that platforms that provide analytical frameworks for assaying specific biological mechanisms and those that take full advantage of integrated technologies to extract high-value quantitative information from worm assays are most likely to move the field forward.
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Affiliation(s)
- Farhan Kamili
- Interdisciplinary Program in Bioengineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Hang Lu
- Interdisciplinary Program in Bioengineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA;
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19
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Barnes DE, Watabe E, Ono K, Kwak E, Kuroyanagi H, Ono S. Tropomyosin isoforms differentially affect muscle contractility in the head and body regions of the nematode Caenorhabditis elegans. Mol Biol Cell 2018; 29:1075-1088. [PMID: 29496965 PMCID: PMC5921574 DOI: 10.1091/mbc.e17-03-0152] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 02/21/2018] [Accepted: 02/23/2018] [Indexed: 11/11/2022] Open
Abstract
Tropomyosin, one of the major actin filament-binding proteins, regulates actin-myosin interaction and actin-filament stability. Multicellular organisms express a number of tropomyosin isoforms, but understanding of isoform-specific tropomyosin functions is incomplete. The nematode Caenorhabditis elegans has a single tropomyosin gene, lev-11, which has been reported to express four isoforms by using two separate promoters and alternative splicing. Here, we report a fifth tropomyosin isoform, LEV-11O, which is produced by alternative splicing that includes a newly identified seventh exon, exon 7a. By visualizing specific splicing events in vivo, we find that exon 7a is predominantly selected in a subset of the body wall muscles in the head, while exon 7b, which is the alternative to exon 7a, is utilized in the rest of the body. Point mutations in exon 7a and exon 7b cause resistance to levamisole--induced muscle contraction specifically in the head and the main body, respectively. Overexpression of LEV-11O, but not LEV-11A, in the main body results in weak levamisole resistance. These results demonstrate that specific tropomyosin isoforms are expressed in the head and body regions of the muscles and contribute differentially to the regulation of muscle contractility.
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Affiliation(s)
- Dawn E. Barnes
- Department of Pathology, Department of Cell Biology, and Winship Cancer Institute, Emory University, Atlanta, GA 30322
| | - Eichi Watabe
- Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Kanako Ono
- Department of Pathology, Department of Cell Biology, and Winship Cancer Institute, Emory University, Atlanta, GA 30322
| | - Euiyoung Kwak
- Department of Pathology, Department of Cell Biology, and Winship Cancer Institute, Emory University, Atlanta, GA 30322
| | - Hidehito Kuroyanagi
- Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Shoichiro Ono
- Department of Pathology, Department of Cell Biology, and Winship Cancer Institute, Emory University, Atlanta, GA 30322
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20
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Cornaglia M, Lehnert T, Gijs MAM. Microfluidic systems for high-throughput and high-content screening using the nematode Caenorhabditis elegans. LAB ON A CHIP 2017; 17:3736-3759. [PMID: 28840220 DOI: 10.1039/c7lc00509a] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In a typical high-throughput drug screening (HTS) process, up to millions of chemical compounds are applied to cells cultured in well plates, aiming to find molecules that exhibit a robust dose-response, as evidenced for example by a fluorescence signal. In high-content screening (HCS), one goes a step further by linking the tested compounds to phenotypic information, obtained, for instance, from microscopic cell images, thereby creating richer data sets that also require more advanced analysis methods. The nematode Caenorhabditis elegans came into the screening picture due to the wide availability of its mutants and human disease models, its relatively easy culture and short life cycle. Being a whole-organism model, it allows drug testing under physiological conditions at multi-tissue levels and provides additional observable phenotypes with respect to cell models, related, for instance, to development, aging, behavior or motility. Worm-based HTS studies in liquid environments on microwell plates have been demonstrated, while microfluidic devices allowed surpassing the performance of plates by enabling more versatile and accurate assays, precise and dynamic dosing of compounds, and readouts down to single-animal resolution. In this review, we discuss microfluidic devices for C. elegans analysis and related studies, published in the period from 2012 to 2017. After an introduction to the different screening approaches, we first focus on microfluidic systems with potential for screening applications. Various enabling technologies, e.g. electrophysiological on-chip recordings or laser axotomy, have been implemented, as well as techniques for reversible worm immobilization and high-resolution imaging, combined with algorithms for automated experimentation and analysis. Several devices for developmental or behavioral assays, and worm sorting based on different phenotypes, have been proposed too. In a subsequent section, we review the application of microfluidic-based systems for medium- and high-throughput screens, including neurobiology and neurodegeneration studies, aging and developmental assays, toxicity and pathogenesis screens, as well as behavioral and motility assays. A thorough analysis of this work reveals a trend towards microfluidic systems more and more capable of offering high-quality analyses of large worm populations, based on multi-phenotypic and/or longitudinal readouts, with clear potential for their application in larger HTS/HCS contexts.
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Affiliation(s)
- Matteo Cornaglia
- Laboratory of Microsystems, École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland.
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21
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Matsunaga Y, Hwang H, Franke B, Williams R, Penley M, Qadota H, Yi H, Morran LT, Lu H, Mayans O, Benian GM. Twitchin kinase inhibits muscle activity. Mol Biol Cell 2017; 28:1591-1600. [PMID: 28428253 PMCID: PMC5469603 DOI: 10.1091/mbc.e16-10-0707] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 04/04/2017] [Accepted: 04/11/2017] [Indexed: 01/03/2023] Open
Abstract
Muscles express giant polypeptides with kinase domains, but the in vivo significance of their catalytic activity has been unknown. Analysis of a mutant nematode that expresses the giant protein twitchin with a catalytically inactive kinase indicates that twitchin kinase inhibits muscle activity and is favored by selection. Muscle sarcomeres contain giant polypeptides composed of multiple immunoglobulin and fibronectin domains and one or two protein kinase domains. Although binding partners for a number of this family’s kinase domains have been identified, the catalytic necessity of these kinase domains remains unknown. In addition, various members of this kinase family are suspected pseudokinases with no or little activity. Here we address catalytic necessity for the first time, using the prototypic invertebrate representative twitchin (UNC-22) from Caenorhabditis elegans. In in vitro experiments, change of a conserved lysine (K) that is involved in ATP coordination to alanine (A) resulted in elimination of kinase activity without affecting the overall structure of the kinase domain. The same mutation, unc-22(sf21), was generated in the endogenous twitchin gene. The unc-22(sf21) worms have well-organized sarcomeres. However, unc-22(sf21) mutants move faster than wild-type worms and, by optogenetic experiments, contract more. Wild-type nematodes exhibited greater competitive fitness than unc-22(sf21) mutants. Thus the catalytic activity of twitchin kinase has a role in vivo, where it inhibits muscle activity and is likely maintained by selection.
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Affiliation(s)
- Yohei Matsunaga
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Hyundoo Hwang
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Barbara Franke
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Rhys Williams
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - McKenna Penley
- Department of Biology, Emory University, Atlanta, GA 30322
| | - Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Hong Yi
- Apkarian Integrated Electron Microscopy Core, Emory University, Atlanta, GA 30322
| | - Levi T Morran
- Department of Biology, Emory University, Atlanta, GA 30322
| | - Hang Lu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Olga Mayans
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Guy M Benian
- Department of Pathology, Emory University, Atlanta, GA 30322
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22
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Barnes DE, Hwang H, Ono K, Lu H, Ono S. Molecular evolution of troponin I and a role of its N-terminal extension in nematode locomotion. Cytoskeleton (Hoboken) 2016; 73:117-30. [PMID: 26849746 DOI: 10.1002/cm.21281] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 01/22/2016] [Accepted: 01/27/2016] [Indexed: 01/29/2023]
Abstract
The troponin complex, composed of troponin T (TnT), troponin I (TnI), and troponin C (TnC), is the major calcium-dependent regulator of muscle contraction, which is present widely in both vertebrates and invertebrates. Little is known about evolutionary aspects of troponin in the animal kingdom. Using a combination of data mining and functional analysis of TnI, we report evidence that an N-terminal extension of TnI is present in most of bilaterian animals as a functionally important domain. Troponin components have been reported in species in most of representative bilaterian phyla. Comparison of TnI sequences shows that the core domains are conserved in all examined TnIs, and that N- and C-terminal extensions are variable among isoforms and species. In particular, N-terminal extensions are present in all protostome TnIs and chordate cardiac TnIs but lost in a subset of chordate TnIs including vertebrate skeletal-muscle isoforms. Transgenic rescue experiments in Caenorhabditis elegans striated muscle show that the N-terminal extension of TnI (UNC-27) is required for coordinated worm locomotion but not in sarcomere assembly and single muscle-contractility kinetics. These results suggest that N-terminal extensions of TnIs are retained from a TnI ancestor as a functional domain.
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Affiliation(s)
- Dawn E Barnes
- Department of Pathology and Department of Cell Biology, Emory University, Atlanta, Georgia
| | - Hyundoo Hwang
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia.,School of Engineering and Sciences, Technológico de Monterrey, Monterrey, Nuevo León, Mexico
| | - Kanako Ono
- Department of Pathology and Department of Cell Biology, Emory University, Atlanta, Georgia
| | - Hang Lu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia.,Interdisciplinary Program of Bioengineering, Georgia Institute of Technology, Atlanta, Georgia.,The Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia
| | - Shoichiro Ono
- Department of Pathology and Department of Cell Biology, Emory University, Atlanta, Georgia
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23
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Hu L, Ge A, Wang X, Wang S, Gao Y, Feng X, Du W, Liu BF. An on-demand gas segmented flow generator with high spatiotemporal resolution for in vivo analysis of neuronal response in C. elegans. LAB ON A CHIP 2016; 16:4020-4027. [PMID: 27714011 DOI: 10.1039/c6lc00948d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Studies of chemo-sensing in C. elegans to fluctuating gaseous cues are limited due to the lack of a method of precise gas control. In this paper, we describe a microfluidic-based on-demand gas segmented flow generator for performing fluctuating gaseous stimulations to worms. This highly versatile and programmable micro-device integrated with pneumatic valves for flexible and stable gas flow control and worm immobilization enabled us to examine the temporal features of neuronal response to multiple gas pulses with sub-second precision. As a result, we demonstrated the capability of the micro-device to generate repetitive gaseous chemical pulses with varying durations. By characterizing intracellular calcium signals, we showed that URX sensory neurons were sensitive to O2 pulses with duration of more than 0.5 s. Furthermore, URX neuronal adaptation and recovery in response to gaseous chemical pulses were investigated by varying the durations and intervals. The developed microfluidic system is shown to be a useful tool for studying the dynamics of in vivo gas-evoked neuronal responses and revealing the temporal properties of environmental stimulations.
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Affiliation(s)
- Liang Hu
- Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China. and Brain Research Center, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Anle Ge
- Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Xixian Wang
- Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Shanshan Wang
- Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Yue Gao
- Optic Information Science & Technology, School of Physics, Sun Yat-Sen University, China
| | - Xiaojun Feng
- Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Wei Du
- Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Bi-Feng Liu
- Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
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24
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Muthaiyan Shanmugam M, Subhra Santra T. Microfluidic Devices in Advanced Caenorhabditis elegans Research. Molecules 2016; 21:molecules21081006. [PMID: 27490525 PMCID: PMC6273278 DOI: 10.3390/molecules21081006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 07/19/2016] [Accepted: 07/27/2016] [Indexed: 01/10/2023] Open
Abstract
The study of model organisms is very important in view of their potential for application to human therapeutic uses. One such model organism is the nematode worm, Caenorhabditis elegans. As a nematode, C. elegans have ~65% similarity with human disease genes and, therefore, studies on C. elegans can be translated to human, as well as, C. elegans can be used in the study of different types of parasitic worms that infect other living organisms. In the past decade, many efforts have been undertaken to establish interdisciplinary research collaborations between biologists, physicists and engineers in order to develop microfluidic devices to study the biology of C. elegans. Microfluidic devices with the power to manipulate and detect bio-samples, regents or biomolecules in micro-scale environments can well fulfill the requirement to handle worms under proper laboratory conditions, thereby significantly increasing research productivity and knowledge. The recent development of different kinds of microfluidic devices with ultra-high throughput platforms has enabled researchers to carry out worm population studies. Microfluidic devices primarily comprises of chambers, channels and valves, wherein worms can be cultured, immobilized, imaged, etc. Microfluidic devices have been adapted to study various worm behaviors, including that deepen our understanding of neuromuscular connectivity and functions. This review will provide a clear account of the vital involvement of microfluidic devices in worm biology.
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Affiliation(s)
- Muniesh Muthaiyan Shanmugam
- Institute of Molecular and Cellular Biology, Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Tuhin Subhra Santra
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600 036, India.
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25
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Gupta BP, Rezai P. Microfluidic Approaches for Manipulating, Imaging, and Screening C. elegans. MICROMACHINES 2016; 7:E123. [PMID: 30404296 PMCID: PMC6190076 DOI: 10.3390/mi7070123] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 06/23/2016] [Accepted: 07/11/2016] [Indexed: 11/17/2022]
Abstract
The nematode C. elegans (worm) is a small invertebrate animal widely used in studies related to fundamental biological processes, disease modelling, and drug discovery. Due to their small size and transparent body, these worms are highly suitable for experimental manipulations. In recent years several microfluidic devices and platforms have been developed to accelerate worm handling, phenotypic studies and screens. Here we review major tools and briefly discuss their usage in C. elegans research.
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Affiliation(s)
- Bhagwati P Gupta
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada.
| | - Pouya Rezai
- Department of Mechanical Engineering, York University, Toronto, ON M3J 1P3, Canada.
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