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Chen Y, Chen Y, Jian B, Feng Q, Liu L. Identification and Expression of Integrins during Testicular Fusion in Spodoptera litura. Genes (Basel) 2023; 14:1452. [PMID: 37510356 PMCID: PMC10379305 DOI: 10.3390/genes14071452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/10/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
Integrin members are cell adhesion receptors that bind to extracellular matrix (ECM) proteins to regulate cell-cell adhesion and cell-ECM adhesion. This process is essential for tissue development and organogenesis. The fusion of two testes is a physiological phenomenon that is required for sperm production and effective reproduction in many Lepidoptera. However, the molecular mechanism of testicular fusion is unclear. In Spodoptera litura, two separated testes fuse into a single testis during the larva-to-pupa transformation. We identified five α and five β integrin subunits that were closely associated with testicular fusion. Integrin α1 and α2 belong to the position-specific 1 (PS1) and PS2 groups, respectively. Integrin α3, αPS1/αPS2, and αPS3 were clustered into the PS3 group. Integrin β1 belonged to the insect β group, and β2, β3, and β5 were clustered in the βν group. Among these integrins, α1, α2, α3, αPS1/PS2, αPS3, β1, and β4 subunits were highly expressed when the testes fused. However, their expression levels were much lower before and after the fusion of the testis. The qRT-PCR and immunohistochemistry analyses indicated that integrin β1 mRNA and the protein were highly expressed in the peritoneal sheath of the testis, particularly when the testes fused. These results indicate that integrins might participate in S. litura testicular fusion.
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Affiliation(s)
- Yaqing Chen
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Yu Chen
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Baozhu Jian
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Qili Feng
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Lin Liu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
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Pérez-Moreno JJ, Santa-Cruz Mateos C, Martín-Bermudo MD, Estrada B. LanB1 Cooperates With Kon-Tiki During Embryonic Muscle Migration in Drosophila. Front Cell Dev Biol 2022; 9:749723. [PMID: 35047493 PMCID: PMC8762229 DOI: 10.3389/fcell.2021.749723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 11/19/2021] [Indexed: 11/13/2022] Open
Abstract
Muscle development is a multistep process that involves cell specification, myoblast fusion, myotube migration, and attachment to the tendons. In spite of great efforts trying to understand the basis of these events, little is known about the molecular mechanisms underlying myotube migration. Knowledge of the few molecular cues that guide this migration comes mainly from studies in Drosophila. The migratory process of Drosophila embryonic muscles involves a first phase of migration, where muscle progenitors migrate relative to each other, and a second phase, where myotubes migrate searching for their future attachment sites. During this phase, myotubes form extensive filopodia at their ends oriented preferentially toward their attachment sites. This myotube migration and the subsequent muscle attachment establishment are regulated by cell adhesion receptors, such as the conserved proteoglycan Kon-tiki/Perdido. Laminins have been shown to regulate the migratory behavior of many cell populations, but their role in myotube migration remains largely unexplored. Here, we show that laminins, previously implicated in muscle attachment, are indeed required for muscle migration to tendon cells. Furthermore, we find that laminins genetically interact with kon-tiki/perdido to control both myotube migration and attachment. All together, our results uncover a new role for the interaction between laminins and Kon-tiki/Perdido during Drosophila myogenesis. The identification of new players and molecular interactions underlying myotube migration broadens our understanding of muscle development and disease.
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Integrated proteomic and transcriptomic profiling identifies aberrant gene and protein expression in the sarcomere, mitochondrial complex I, and the extracellular matrix in Warmblood horses with myofibrillar myopathy. BMC Genomics 2021; 22:438. [PMID: 34112090 PMCID: PMC8194174 DOI: 10.1186/s12864-021-07758-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 05/26/2021] [Indexed: 02/06/2023] Open
Abstract
Background Myofibrillar myopathy in humans causes protein aggregation, degeneration, and weakness of skeletal muscle. In horses, myofibrillar myopathy is a late-onset disease of unknown origin characterized by poor performance, atrophy, myofibrillar disarray, and desmin aggregation in skeletal muscle. This study evaluated molecular and ultrastructural signatures of myofibrillar myopathy in Warmblood horses through gluteal muscle tandem-mass-tag quantitative proteomics (5 affected, 4 control), mRNA-sequencing (8 affected, 8 control), amalgamated gene ontology analyses, and immunofluorescent and electron microscopy. Results We identified 93/1533 proteins and 47/27,690 genes that were significantly differentially expressed. The top significantly differentially expressed protein CSRP3 and three other differentially expressed proteins, including, PDLIM3, SYNPO2, and SYNPOL2, are integrally involved in Z-disc signaling, gene transcription and subsequently sarcomere integrity. Through immunofluorescent staining, both desmin aggregates and CSRP3 were localized to type 2A fibers. The highest differentially expressed gene CHAC1, whose protein product degrades glutathione, is associated with oxidative stress and apoptosis. Amalgamated transcriptomic and proteomic gene ontology analyses identified 3 enriched cellular locations; the sarcomere (Z-disc & I-band), mitochondrial complex I and the extracellular matrix which corresponded to ultrastructural Z-disc disruption and mitochondrial cristae alterations found with electron microscopy. Conclusions A combined proteomic and transcriptomic analysis highlighted three enriched cellular locations that correspond with MFM ultrastructural pathology in Warmblood horses. Aberrant Z-disc mechano-signaling, impaired Z-disc stability, decreased mitochondrial complex I expression, and a pro-oxidative cellular environment are hypothesized to contribute to the development of myofibrillar myopathy in Warmblood horses. These molecular signatures may provide further insight into diagnostic biomarkers, treatments, and the underlying pathophysiology of MFM. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07758-0.
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Chakraborty N, Waning DL, Gautam A, Hoke A, Sowe B, Youssef D, Butler S, Savaglio M, Childress PJ, Kumar R, Moyler C, Dimitrov G, Kacena MA, Hammamieh R. Gene-Metabolite Network Linked to Inhibited Bioenergetics in Association With Spaceflight-Induced Loss of Male Mouse Quadriceps Muscle. J Bone Miner Res 2020; 35:2049-2057. [PMID: 32511780 PMCID: PMC7689867 DOI: 10.1002/jbmr.4102] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 05/21/2020] [Accepted: 06/01/2020] [Indexed: 12/19/2022]
Abstract
Prolonged residence of mice in spaceflight is a scientifically robust and ethically ratified model of muscle atrophy caused by continued unloading. Under the Rodent Research Program of the National Aeronautics and Space Administration (NASA), we assayed the large-scale mRNA and metabolomic perturbations in the quadriceps of C57BL/6j male mice that lived in spaceflight (FLT) or on the ground (control or CTR) for approximately 4 weeks. The wet weights of the quadriceps were significantly reduced in FLT mice. Next-generation sequencing and untargeted mass spectroscopic assays interrogated the gene-metabolite landscape of the quadriceps. A majority of top-ranked differentially suppressed genes in FLT encoded proteins from the myosin or troponin families, suggesting sarcomere alterations in space. Significantly enriched gene-metabolite networks were found linked to sarcomeric integrity, immune fitness, and oxidative stress response; all inhibited in space as per in silico prediction. A significant loss of mitochondrial DNA copy numbers in FLT mice underlined the energy deprivation associated with spaceflight-induced stress. This hypothesis was reinforced by the transcriptomic sequencing-metabolomics integrative analysis that showed inhibited networks related to protein, lipid, and carbohydrate metabolism, and adenosine triphosphate (ATP) synthesis and hydrolysis. Finally, we discovered important upstream regulators, which could be targeted for next-generation therapeutic intervention for chronic disuse of the musculoskeletal system. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.
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Affiliation(s)
- Nabarun Chakraborty
- The Geneva Foundation, Walter Reed Army Institute of Research, Silver Spring, MD, USA.,Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | | | - Aarti Gautam
- Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Allison Hoke
- Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, USA.,Oak Ridge Institute for Science and Education (ORISE), Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Bintu Sowe
- Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, USA.,Oak Ridge Institute for Science and Education (ORISE), Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Dana Youssef
- Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, USA.,Oak Ridge Institute for Science and Education (ORISE), Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Stephan Butler
- The Geneva Foundation, Walter Reed Army Institute of Research, Silver Spring, MD, USA.,Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Michael Savaglio
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Paul J Childress
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Raina Kumar
- Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Candace Moyler
- Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, USA.,Oak Ridge Institute for Science and Education (ORISE), Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - George Dimitrov
- The Geneva Foundation, Walter Reed Army Institute of Research, Silver Spring, MD, USA.,Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Melissa A Kacena
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.,Richard L. Roudebush VA Medical Center, Indianapolis, IN, USA
| | - Rasha Hammamieh
- Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD, USA
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Poovathumkadavil P, Jagla K. Genetic Control of Muscle Diversification and Homeostasis: Insights from Drosophila. Cells 2020; 9:cells9061543. [PMID: 32630420 PMCID: PMC7349286 DOI: 10.3390/cells9061543] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/19/2020] [Accepted: 06/23/2020] [Indexed: 12/13/2022] Open
Abstract
In the fruit fly, Drosophila melanogaster, the larval somatic muscles or the adult thoracic flight and leg muscles are the major voluntary locomotory organs. They share several developmental and structural similarities with vertebrate skeletal muscles. To ensure appropriate activity levels for their functions such as hatching in the embryo, crawling in the larva, and jumping and flying in adult flies all muscle components need to be maintained in a functionally stable or homeostatic state despite constant strain. This requires that the muscles develop in a coordinated manner with appropriate connections to other cell types they communicate with. Various signaling pathways as well as extrinsic and intrinsic factors are known to play a role during Drosophila muscle development, diversification, and homeostasis. In this review, we discuss genetic control mechanisms of muscle contraction, development, and homeostasis with particular emphasis on the contractile unit of the muscle, the sarcomere.
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Type IV Collagen Is Essential for Proper Function of Integrin-Mediated Adhesion in Drosophila Muscle Fibers. Int J Mol Sci 2019; 20:ijms20205124. [PMID: 31623094 PMCID: PMC6829409 DOI: 10.3390/ijms20205124] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/09/2019] [Accepted: 10/13/2019] [Indexed: 01/18/2023] Open
Abstract
Congenital muscular dystrophy (CMD), a subgroup of myopathies is a genetically and clinically heterogeneous group of inherited muscle disorders and is characterized by progressive muscle weakness, fiber size variability, fibrosis, clustered necrotic fibers, and central myonuclei present in regenerating muscle. Type IV collagen (COL4A1) mutations have recently been identified in patients with intracerebral, vascular, renal, ophthalmologic pathologies and congenital muscular dystrophy, consistent with diagnoses of Walker–Warburg Syndrome or Muscle–Eye–Brain disease. Morphological characteristics of muscular dystrophy have also been demonstrated Col4a1 mutant mice. Yet, several aspects of the pathomechanism of COL4A1-associated muscle defects remained largely uncharacterized. Based on the results of genetic, histological, molecular, and biochemical analyses in an allelic series of Drosophila col4a1 mutants, we provide evidence that col4a1 mutations arise by transitions in glycine triplets, associate with severely compromised muscle fibers within the single-layer striated muscle of the common oviduct, characterized by loss of sarcomere structure, disintegration and streaming of Z-discs, indicating an essential role for the COL4A1 protein. Features of altered cytoskeletal phenotype include actin bundles traversing over sarcomere units, amorphous actin aggregates, atrophy, and aberrant fiber size. The mutant COL4A1-associated defects appear to recapitulate integrin-mediated adhesion phenotypes observed in RNA-inhibitory Drosophila. Our results provide insight into the mechanistic details of COL4A1-associated muscle disorders and suggest a role for integrin-collagen interaction in the maintenance of sarcomeres.
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Lionello VM, Nicot AS, Sartori M, Kretz C, Kessler P, Buono S, Djerroud S, Messaddeq N, Koebel P, Prokic I, Hérault Y, Romero NB, Laporte J, Cowling BS. Amphiphysin 2 modulation rescues myotubular myopathy and prevents focal adhesion defects in mice. Sci Transl Med 2019; 11:11/484/eaav1866. [DOI: 10.1126/scitranslmed.aav1866] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 11/14/2018] [Accepted: 02/28/2019] [Indexed: 12/13/2022]
Abstract
Centronuclear myopathies (CNMs) are severe diseases characterized by muscle weakness and myofiber atrophy. Currently, there are no approved treatments for these disorders. Mutations in the phosphoinositide 3-phosphatase myotubularin (MTM1) are responsible for X-linked CNM (XLCNM), also called myotubular myopathy, whereas mutations in the membrane remodeling Bin/amphiphysin/Rvs protein amphiphysin 2 [bridging integrator 1 (BIN1)] are responsible for an autosomal form of the disease. Here, we investigated the functional relationship between MTM1 and BIN1 in healthy skeletal muscle and in the physiopathology of CNM. Genetic overexpression of human BIN1 efficiently rescued the muscle weakness and life span in a mouse model of XLCNM. Exogenous human BIN1 expression with adeno-associated virus after birth also prevented the progression of the disease, suggesting that human BIN1 overexpression can compensate for the lack of MTM1 expression in this mouse model. Our results showed that MTM1 controls cell adhesion and integrin localization in mammalian muscle. Alterations in this pathway in Mtm1−/y mice were associated with defects in myofiber shape and size. BIN1 expression rescued integrin and laminin alterations and restored myofiber integrity, supporting the idea that MTM1 and BIN1 are functionally linked and necessary for focal adhesions in skeletal muscle. The results suggest that BIN1 modulation might be an effective strategy for treating XLCNM.
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8
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Deletion of the Ste20-like kinase SLK in skeletal muscle results in a progressive myopathy and muscle weakness. Skelet Muscle 2017; 7:3. [PMID: 28153048 PMCID: PMC5288853 DOI: 10.1186/s13395-016-0119-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 12/26/2016] [Indexed: 12/16/2022] Open
Abstract
Background The Ste20-like kinase, SLK, plays an important role in cell proliferation and cytoskeletal remodeling. In fibroblasts, SLK has been shown to respond to FAK/Src signaling and regulate focal adhesion turnover through Paxillin phosphorylation. Full-length SLK has also been shown to be essential for embryonic development. In myoblasts, the overexpression of a dominant negative SLK is sufficient to block myoblast fusion. Methods In this study, we crossed the Myf5-Cre mouse model with our conditional SLK knockout model to delete SLK in skeletal muscle. A thorough analysis of skeletal muscle tissue was undertaken in order to identify defects in muscle development caused by the lack of SLK. Isometric force analysis was performed on adult knockout mice and compared to age-matched wild-type mice. Furthermore, cardiotoxin injections were performed followed by immunohistochemistry for myogenic markers to assess the efficiency muscle regeneration following SLK deletion. Results We show here that early deletion of SLK from the myogenic lineage does not markedly impair skeletal muscle development but delays the regenerative process. Interestingly, adult mice (~6 months) display an increase in the proportion of central nuclei and increased p38 activation. Furthermore, mice as young as 3 months old present with decreased force generation, suggesting that the loss of SLK impairs myofiber stability and function. Assessment of structural components revealed aberrant localization of focal adhesion proteins, such as FAK and paxillin. Our data show that the loss of SLK results in unstable myofibers resulting in a progressive myopathy. Additionally, the loss of SLK resulted in a delay in muscle regeneration following cardiotoxin injections. Conclusions Our results show that SLK is dispensable for muscle development and regeneration but is required for myofiber stability and optimal force generation. Electronic supplementary material The online version of this article (doi:10.1186/s13395-016-0119-1) contains supplementary material, which is available to authorized users.
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Auld AL, Folker ES. Nucleus-dependent sarcomere assembly is mediated by the LINC complex. Mol Biol Cell 2016; 27:2351-9. [PMID: 27307582 PMCID: PMC4966977 DOI: 10.1091/mbc.e16-01-0021] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 06/07/2016] [Indexed: 12/22/2022] Open
Abstract
Two defining characteristics of muscle cells are the many precisely positioned nuclei and the linearly arranged sarcomeres, yet the relationship between these two features is not known. We show that nuclear positioning precedes sarcomere formation. Furthermore, ZASP-GFP, a Z-line protein, colocalizes with F-actin in puncta at the cytoplasmic face of nuclei before sarcomere assembly. In embryos with mispositioned nuclei, ZASP-GFP is still recruited to the nuclei before its incorporation into sarcomeres. Furthermore, the first sarcomeres appear in positions close to the nuclei, regardless of nuclear position. These data suggest that the interaction between sarcomere proteins and nuclei is not dependent on properly positioned nuclei. Mechanistically, ZASP-GFP localization to the cytoplasmic face of the nucleus did require the linker of nucleoskeleton and cytoskeleton (LINC) complex. Muscle-specific depletion of klarsicht (nesprin) or klariod (SUN) blocked the recruitment of ZASP-GFP to the nucleus during the early stages of sarcomere assembly. As a result, sarcomeres were poorly formed and the general myofibril network was less stable, incomplete, and/or torn. These data suggest that the nucleus, through the LINC complex, is crucial for the proper assembly and stability of the sarcomere network.
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Affiliation(s)
| | - Eric S Folker
- Department of Biology, Boston College, Chestnut Hill, MA 02467
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10
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Gribova V, Liu CY, Nishiguchi A, Matsusaki M, Boudou T, Picart C, Akashi M. Construction and myogenic differentiation of 3D myoblast tissues fabricated by fibronectin-gelatin nanofilm coating. Biochem Biophys Res Commun 2016; 474:515-521. [PMID: 27125461 DOI: 10.1016/j.bbrc.2016.04.130] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Accepted: 04/24/2016] [Indexed: 11/16/2022]
Abstract
In this study, we used a recently developed approach of coating the cells with fibronectin-gelatin nanofilms to build 3D skeletal muscle tissue models. We constructed the microtissues from C2C12 myoblasts and subsequently differentiated them to form muscle-like tissue. The thickness of the constructs could be successfully controlled by altering the number of seeded cells. We were able to build up to ∼76 μm thick 3D constructs that formed multinucleated myotubes. We also found that Rho-kinase inhibitor Y27632 improved myotube formation in thick constructs. Our approach makes it possible to rapidly form 3D muscle tissues and is promising for the in vitro construction of physiologically relevant human skeletal muscle tissue models.
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Affiliation(s)
- Varvara Gribova
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Chun-Yen Liu
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Akihiro Nishiguchi
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Michiya Matsusaki
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Thomas Boudou
- Grenoble Institute of Technology, CNRS UMR 5628, Laboratory of Materials and Physical Engineering, 3 Parvis L. Néel, 38016 Grenoble, France
| | - Catherine Picart
- Grenoble Institute of Technology, CNRS UMR 5628, Laboratory of Materials and Physical Engineering, 3 Parvis L. Néel, 38016 Grenoble, France.
| | - Mitsuru Akashi
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Gribova V, Pignot-Paintrand I, Fourel L, Auzely-Velty R, Albigès-Rizo C, Gauthier-Rouvière C, Picart C. Control of the Proliferation/Differentiation Balance in Skeletal Myoblasts by Integrin and Syndecan Targeting Peptides. ACS Biomater Sci Eng 2016; 2:415-425. [DOI: 10.1021/acsbiomaterials.5b00557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Varvara Gribova
- LMGP, Université Grenoble Alpes, F-38016 Grenoble, France
- CNRS, LMGP, F-38016 Grenoble, France
- Centre
de Recherches sur les Macromolécules Végétales
(CERMAV, CNRS UPR 5301), Université Joseph Fourier, 38041 St. Martin d’Hères, France
- Institut
de Chimie Moléculaire de Grenoble, Domaine Universitaire de Grenoble, 601 rue de la Chimie, 38421 St. Martin d’Hères, France
- CERMAV, CNRS, F-38016 Grenoble, France
| | | | - Laure Fourel
- INSERM
U823, ERL CNRS5284, Université Joseph Fourier, Institut Albert Bonniot, Site Santé, BP170, 38042 Grenoble Cedex 9, France
| | - Rachel Auzely-Velty
- Centre
de Recherches sur les Macromolécules Végétales
(CERMAV, CNRS UPR 5301), Université Joseph Fourier, 38041 St. Martin d’Hères, France
- Institut
de Chimie Moléculaire de Grenoble, Domaine Universitaire de Grenoble, 601 rue de la Chimie, 38421 St. Martin d’Hères, France
- CERMAV, CNRS, F-38016 Grenoble, France
| | - Corinne Albigès-Rizo
- INSERM
U823, ERL CNRS5284, Université Joseph Fourier, Institut Albert Bonniot, Site Santé, BP170, 38042 Grenoble Cedex 9, France
| | - Cécile Gauthier-Rouvière
- CRBM, Universités Montpellier 2 et 1, F-34293 Montpellier, France
- CRBM, CNRS, F-34293 Montpellier, France
| | - Catherine Picart
- LMGP, Université Grenoble Alpes, F-38016 Grenoble, France
- CNRS, LMGP, F-38016 Grenoble, France
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Bogatan S, Cevik D, Demidov V, Vanderploeg J, Panchbhaya A, Vitkin A, Jacobs JR. Talin Is Required Continuously for Cardiomyocyte Remodeling during Heart Growth in Drosophila. PLoS One 2015; 10:e0131238. [PMID: 26110760 PMCID: PMC4482443 DOI: 10.1371/journal.pone.0131238] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 05/30/2015] [Indexed: 12/26/2022] Open
Abstract
Mechanotransduction of tension can govern the remodeling of cardiomyocytes during growth or cardiomyopathy. Tension is signaled through the integrin adhesion complexes found at muscle insertions and costameres but the relative importance of signalling during cardiomyocyte growth versus remodelling has not been assessed. Employing the Drosophila cardiomyocyte as a genetically amenable model, we depleted the levels of Talin, a central component of the integrin adhesion complex, at different stages of heart growth and remodeling. We demonstrate a continuous requirement for Talin during heart growth to maintain the one-to-one apposition of myofibril ends between cardiomyocytes. Retracted myofibrils cannot regenerate appositions to adjacent cells after restoration of normal Talin expression, and the resulting deficit reduces heart contraction and lifespan. Reduction of Talin during heart remodeling after hatching or during metamorphosis results in pervasive degeneration of cell contacts, myofibril length and number, for which restored Talin expression is insufficient for regeneration. Resultant dilated cardiomyopathy results in a fibrillating heart with poor rhythmicity. Cardiomyocytes have poor capacity to regenerate deficits in myofibril orientation and insertion, despite an ongoing capacity to remodel integrin based adhesions.
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Affiliation(s)
- Simina Bogatan
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Duygu Cevik
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Valentin Demidov
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Jessica Vanderploeg
- Department of Biology, Taylor University, Euler Science Complex, 236 W. Reade Ave, Upland, IN, 46989, United States of America
| | | | - Alex Vitkin
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - J. Roger Jacobs
- Department of Biology, McMaster University, Hamilton, ON, Canada
- * E-mail:
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13
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Maartens AP, Brown NH. The many faces of cell adhesion during Drosophila muscle development. Dev Biol 2015; 401:62-74. [DOI: 10.1016/j.ydbio.2014.12.038] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 12/17/2014] [Accepted: 12/19/2014] [Indexed: 10/24/2022]
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Zheng JC, Tham CT, Keatings K, Fan S, Liou AYC, Numata Y, Allan D, Numata M. Secretory Carrier Membrane Protein (SCAMP) deficiency influences behavior of adult flies. Front Cell Dev Biol 2014; 2:64. [PMID: 25478561 PMCID: PMC4235465 DOI: 10.3389/fcell.2014.00064] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 10/17/2014] [Indexed: 12/21/2022] Open
Abstract
Secretory Carrier Membrane Proteins (SCAMPs) are a group of tetraspanning integral membrane proteins evolutionarily conserved from insects to mammals and plants. Mammalian genomes contain five SCAMP genes SCAMP1-SCAMP5 that regulate membrane dynamics, most prominently membrane-depolarization and Ca2+-induced regulated secretion, a key mechanism for neuronal and neuroendocrine signaling. However, the biological role of SCAMPs has remained poorly understood primarily owing to the lack of appropriate model organisms and behavior assays. Here we generate Drosophila Scamp null mutants and show that they exhibit reduced lifespan and behavioral abnormalities including impaired climbing, deficiency in odor associated long-term memory, and a susceptibility to heat-induced seizures. Neuron-specific restoration of Drosophila Scamp rescues all Scamp null behavioral phenotypes, indicating that the phenotypes are due to loss of neuronal Scamp. Remarkably, neuronal expression of human SCAMP genes rescues selected behavioral phenotypes of the mutants, suggesting the conserved function of SCAMPs across species. The newly developed Drosophila mutants present the first evidence that genetic depletion of SCAMP at the organismal level leads to varied behavioral abnormalities, and the obtained results indicate the importance of membrane dynamics in neuronal functions in vivo.
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Affiliation(s)
- JiaLin C Zheng
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
| | - Chook Teng Tham
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
| | - Kathleen Keatings
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
| | - Steven Fan
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
| | - Angela Yen-Chun Liou
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
| | - Yuka Numata
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
| | - Douglas Allan
- Department of Cellular and Physiological Sciences, University of British Columbia Vancouver, BC, Canada
| | - Masayuki Numata
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver, BC, Canada
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15
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Interaction of infectious spleen and kidney necrosis virus ORF119L with PINCH leads to dominant-negative inhibition of integrin-linked kinase and cardiovascular defects in zebrafish. J Virol 2014; 89:763-75. [PMID: 25355883 DOI: 10.1128/jvi.01955-14] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
UNLABELLED Infectious spleen and kidney necrosis virus (ISKNV) is the type species of the Megalocytivirus genus, Iridoviridae family, causing a severe systemic disease with high mortality in mandarin fish (Siniperca chuatsi) in China and Southeast Asia. At present, the pathogenesis of ISKNV infection is still not fully understood. Based on a genome-wide bioinformatics analysis of ISKNV-encoded proteins, we found that ISKNV open reading frame 119L (ORF119L) is predicted to encode a three-ankyrin-repeat (3ANK)-domain-containing protein, which shows high similarity to the dominant negative form of integrin-linked kinase (ILK); i.e., viral ORF119L lacks the ILK kinase domain. Thus, we speculated that viral ORF119L might affect the host ILK complex. Here, we demonstrated that viral ORF119L directly interacts with particularly interesting Cys-His-rich protein (PINCH) and affects the host ILK-PINCH interaction in vitro in fathead minnow (FHM) cells. In vivo ORF119L overexpression in zebrafish (Danio rerio) embryos resulted in myocardial dysfunctions with disintegration of the sarcomeric Z disk. Importantly, ORF119L overexpression in zebrafish highly resembles the phenotype of endogenous ILK inhibition, either by overexpressing a dominant negative form of ILK or by injecting an ILK antisense morpholino oligonucleotide. Intriguingly, ISKNV-infected mandarin fish develop disorganized sarcomeric Z disks in cardiomyocytes. Furthermore, phosphorylation of AKT, a downstream effector of ILK, was remarkably decreased in ORF119L-overexpressing zebrafish embryos. With these results, we show that ISKNV ORF119L acts as a domain-negative inhibitor of the host ILK, providing a novel mechanism for the megalocytivirus pathogenesis. IMPORTANCE Our work is the first to show the role of a dominant negative inhibitor of the host ILK from ISKNV (an iridovirus). Mechanistically, the viral ORF119L directly binds to the host PINCH, attenuates the host PINCH-ILK interaction, and thus impairs ILK signaling. Intriguingly, ORF119L-overexpressing zebrafish embryos and ISKNV-infected mandarin fish develop similar disordered sarcomeric Z disks in cardiomyocytes. These findings provide a novel mechanism for megalocytivirus pathogenesis.
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16
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Xie X, Gilbert M, Petley-Ragan L, Auld VJ. Loss of focal adhesions in glia disrupts both glial and photoreceptor axon migration in the Drosophila visual system. Development 2014; 141:3072-83. [PMID: 25053436 DOI: 10.1242/dev.101972] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Many aspects of glial development are regulated by extracellular signals, including those from the extracellular matrix (ECM). Signals from the ECM are received by cell surface receptors, including the integrin family. Previously, we have shown that Drosophila integrins form adhesion complexes with Integrin-linked kinase and talin in the peripheral nerve glia and have conserved roles in glial sheath formation. However, integrin function in other aspects of glial development is unclear. The Drosophila eye imaginal disc (ED) and optic stalk (OS) complex is an excellent model with which to study glial migration, differentiation and glia-neuron interactions. We studied the roles of the integrin complexes in these glial developmental processes during OS/eye development. The common beta subunit βPS and two alpha subunits, αPS2 and αPS3, are located in puncta at both glia-glia and glia-ECM interfaces. Depletion of βPS integrin and talin by RNAi impaired the migration and distribution of glia within the OS resulting in morphological defects. Reduction of integrin or talin in the glia also disrupted photoreceptor axon outgrowth leading to axon stalling in the OS and ED. The neuronal defects were correlated with a disruption of the carpet glia tube paired with invasion of glia into the core of the OS and the formation of a glial cap. Our results suggest that integrin-mediated extracellular signals are important for multiple aspects of glial development and non-autonomously affect axonal migration during Drosophila eye development.
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Affiliation(s)
- Xiaojun Xie
- Department of Zoology, Cell and Developmental Biology, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3
| | - Mary Gilbert
- Department of Zoology, Cell and Developmental Biology, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3
| | - Lindsay Petley-Ragan
- Department of Zoology, Cell and Developmental Biology, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3
| | - Vanessa J Auld
- Department of Zoology, Cell and Developmental Biology, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3
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17
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Perkins AD, Tanentzapf G. An ongoing role for structural sarcomeric components in maintaining Drosophila melanogaster muscle function and structure. PLoS One 2014; 9:e99362. [PMID: 24915196 PMCID: PMC4051695 DOI: 10.1371/journal.pone.0099362] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 05/14/2014] [Indexed: 11/29/2022] Open
Abstract
Animal muscles must maintain their function while bearing substantial mechanical loads. How muscles withstand persistent mechanical strain is presently not well understood. The basic unit of muscle is the sarcomere, which is primarily composed of cytoskeletal proteins. We hypothesized that cytoskeletal protein turnover is required to maintain muscle function. Using the flight muscles of Drosophila melanogaster, we confirmed that the sarcomeric cytoskeleton undergoes turnover throughout adult life. To uncover which cytoskeletal components are required to maintain adult muscle function, we performed an RNAi-mediated knockdown screen targeting the entire fly cytoskeleton and associated proteins. Gene knockdown was restricted to adult flies and muscle function was analyzed with behavioural assays. Here we analyze the results of that screen and characterize the specific muscle maintenance role for several hits. The screen identified 46 genes required for muscle maintenance: 40 of which had no previously known role in this process. Bioinformatic analysis highlighted the structural sarcomeric proteins as a candidate group for further analysis. Detailed confocal and electron microscopic analysis showed that while muscle architecture was maintained after candidate gene knockdown, sarcomere length was disrupted. Specifically, we found that ongoing synthesis and turnover of the key sarcomere structural components Projectin, Myosin and Actin are required to maintain correct sarcomere length and thin filament length. Our results provide in vivo evidence of adult muscle protein turnover and uncover specific functional defects associated with reduced expression of a subset of cytoskeletal proteins in the adult animal.
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Affiliation(s)
- Alexander D. Perkins
- Department of Cellular and Physiological Sciences, University of British Columbia, Life Sciences Institute, Vancouver, British Columbia, Canada
| | - Guy Tanentzapf
- Department of Cellular and Physiological Sciences, University of British Columbia, Life Sciences Institute, Vancouver, British Columbia, Canada
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18
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Nishimura M, Kumsta C, Kaushik G, Diop SB, Ding Y, Bisharat-Kernizan J, Catan H, Cammarato A, Ross RS, Engler AJ, Bodmer R, Hansen M, Ocorr K. A dual role for integrin-linked kinase and β1-integrin in modulating cardiac aging. Aging Cell 2014; 13:431-40. [PMID: 24400780 PMCID: PMC4032615 DOI: 10.1111/acel.12193] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2013] [Indexed: 12/19/2022] Open
Abstract
Cardiac performance decreases with age, which is a major risk factor for cardiovascular disease and mortality in the aging human population, but the molecular mechanisms underlying cardiac aging are still poorly understood. Investigating the role of integrin-linked kinase (ilk) and β1-integrin (myospheroid, mys) in Drosophila, which colocalize near cardiomyocyte contacts and Z-bands, we find that reduced ilk or mys function prevents the typical changes of cardiac aging seen in wildtype, such as arrhythmias. In particular, the characteristic increase in cardiac arrhythmias with age is prevented in ilk and mys heterozygous flies with nearly identical genetic background, and they live longer, in line with previous findings in Caenorhabditis elegans for ilk and in Drosophila for mys. Consistent with these findings, we observed elevated β1-integrin protein levels in old compared with young wild-type flies, and cardiac-specific overexpression of mys in young flies causes aging-like heart dysfunction. Moreover, moderate cardiac-specific knockdown of integrin-linked kinase (ILK)/integrin pathway-associated genes also prevented the decline in cardiac performance with age. In contrast, strong cardiac knockdown of ilk or ILK-associated genes can severely compromise cardiac integrity, including cardiomyocyte adhesion and overall heart function. These data suggest that ilk/mys function is necessary for establishing and maintaining normal heart structure and function, and appropriate fine-tuning of this pathway can retard the age-dependent decline in cardiac performance and extend lifespan. Thus, ILK/integrin-associated signaling emerges as an important and conserved genetic mechanism in longevity, and as a new means to improve age-dependent cardiac performance, in addition to its vital role in maintaining cardiac integrity.
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Affiliation(s)
- Mayuko Nishimura
- Development, Aging and Regeneration Program; Sanford-Burnham Medical Research Institute; 10901 North Torrey Pines Road La Jolla CA 92037 USA
| | - Caroline Kumsta
- Development, Aging and Regeneration Program; Sanford-Burnham Medical Research Institute; 10901 North Torrey Pines Road La Jolla CA 92037 USA
| | - Gaurav Kaushik
- Sanford Consortium for Regenerative Medicine; University of California at San Diego; 2880 Torrey Pines Scenic Drive La Jolla CA 92037 USA
| | - Soda B. Diop
- Development, Aging and Regeneration Program; Sanford-Burnham Medical Research Institute; 10901 North Torrey Pines Road La Jolla CA 92037 USA
| | - Yun Ding
- School of Medicine; VA San Diego Healthcare System; University of California at San Diego; 3350 La Jolla Village Drive, Cardiology Section 111A San Diego CA 92161 USA
| | - Jumana Bisharat-Kernizan
- Development, Aging and Regeneration Program; Sanford-Burnham Medical Research Institute; 10901 North Torrey Pines Road La Jolla CA 92037 USA
| | - Hannah Catan
- Development, Aging and Regeneration Program; Sanford-Burnham Medical Research Institute; 10901 North Torrey Pines Road La Jolla CA 92037 USA
| | - Anthony Cammarato
- Division of Cardiology; Department of Medicine; School of Medicine; Johns Hopkins University; Baltimore MD 21287 USA
| | - Robert S. Ross
- School of Medicine; VA San Diego Healthcare System; University of California at San Diego; 3350 La Jolla Village Drive, Cardiology Section 111A San Diego CA 92161 USA
| | - Adam J. Engler
- Sanford Consortium for Regenerative Medicine; University of California at San Diego; 2880 Torrey Pines Scenic Drive La Jolla CA 92037 USA
| | - Rolf Bodmer
- Development, Aging and Regeneration Program; Sanford-Burnham Medical Research Institute; 10901 North Torrey Pines Road La Jolla CA 92037 USA
| | - Malene Hansen
- Development, Aging and Regeneration Program; Sanford-Burnham Medical Research Institute; 10901 North Torrey Pines Road La Jolla CA 92037 USA
| | - Karen Ocorr
- Development, Aging and Regeneration Program; Sanford-Burnham Medical Research Institute; 10901 North Torrey Pines Road La Jolla CA 92037 USA
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19
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Pérez-Moreno JJ, Bischoff M, Martín-Bermudo MD, Estrada B. The conserved transmembrane proteoglycan Perdido/Kon-tiki is essential for myofibrillogenesis and sarcomeric structure in Drosophila. J Cell Sci 2014; 127:3162-73. [PMID: 24794494 PMCID: PMC4095857 DOI: 10.1242/jcs.150425] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Muscle differentiation requires the assembly of high-order structures called myofibrils, composed of sarcomeres. Even though the molecular organization of sarcomeres is well known, the mechanisms underlying myofibrillogenesis are poorly understood. It has been proposed that integrin-dependent adhesion nucleates myofibrils at the periphery of the muscle cell to sustain sarcomere assembly. Here, we report a role for the gene perdido (perd, also known as kon-tiki, a transmembrane chondroitin proteoglycan) in myofibrillogenesis. Expression of perd RNAi in muscles, prior to adult myogenesis, can induce misorientation and detachment of Drosophila adult abdominal muscles. In comparison to controls, perd-depleted muscles contain fewer myofibrils, which are localized at the cell periphery. These myofibrils are detached from each other and display a defective sarcomeric structure. Our results demonstrate that the extracellular matrix receptor Perd has a specific role in the assembly of myofibrils and in sarcomeric organization. We suggest that Perd acts downstream or in parallel to integrins to enable the connection of nascent myofibrils to the Z-bands. Our work identifies the Drosophila adult abdominal muscles as a model to investigate in vivo the mechanisms behind myofibrillogenesis.
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Affiliation(s)
- Juan J Pérez-Moreno
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC, 41013 Seville, Spain
| | - Marcus Bischoff
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK
| | - Maria D Martín-Bermudo
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC, 41013 Seville, Spain
| | - Beatriz Estrada
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC, 41013 Seville, Spain
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20
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The systematic identification of cytoskeletal genes required for Drosophila melanogaster muscle maintenance. Sci Data 2014; 1:140002. [PMID: 25977760 PMCID: PMC4365872 DOI: 10.1038/sdata.2014.2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 01/23/2014] [Indexed: 11/18/2022] Open
Abstract
Animal muscles must maintain their function and structure while bearing substantial mechanical loads. How muscles withstand persistent mechanical strain is presently not well understood. Understanding the mechanisms by which tissues maintain their complex architecture is a key goal of cell biology. This dataset represents a systematic screen through the Drosophila melanogaster cytoskeleton to identify genes that are required to maintain tissue, specifically muscle, architecture. Using RNA interference (RNAi), we knocked down 238 genes in Drosophila and assayed for climbing ability with a robust behavioural assay. Here we present the summary of the screen and provide the complete results of the assays. We have uncovered a number of novel hits that would reward further study. The data are easy to use: the raw data are provided to allow researchers to perform their own analysis and analysed results are given indicating whether or not the genes are required for muscle maintenance. This dataset will allow other researchers to identify candidate genes for more detailed study and lead to better understanding of muscle maintenance.
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21
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Grover S, Arya R. Role of UDP-N-acetylglucosamine2-epimerase/N-acetylmannosamine kinase (GNE) in β1-integrin-mediated cell adhesion. Mol Neurobiol 2014; 50:257-73. [PMID: 24474513 DOI: 10.1007/s12035-013-8604-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 12/08/2013] [Indexed: 12/13/2022]
Abstract
Hereditary inclusion body myopathy (GNE myopathy) is a neuromuscular disorder due to mutation in key sialic acid biosynthetic enzyme, GNE. The pathomechanism of the disease is poorly understood as GNE is involved in other cellular functions beside sialic acid synthesis. In the present study, a HEK293 cell-based model system has been established where GNE is either knocked down or over-expressed along with pathologically relevant GNE mutants (D176V and V572L). The subcellular distribution of recombinant GNE and its mutant showed differential localization in the cell. The effect of mutation on GNE function was investigated by studying hyposialylation of cell membrane receptor, β1-integrin. Hyposialylated β1-integrin localized to internal vesicles that was restored upon supplementation with sialic acid. Fibronectin stimulation caused migration of hyposialylated β1-integrin to the cell membrane and co-localization with focal adhesion kinase (FAK) leading to increased focal adhesion formation. This further activated FAK and Src, downstream signaling molecules and led to increased cell adhesion. This is the first report to show that mutation in GNE affects β1-integrin-mediated cell adhesion process in GNE mutant cells.
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Affiliation(s)
- Sonam Grover
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
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22
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Abstract
Skeletal muscle undergoes marked functional decay during aging in humans, but the cell biological mechanisms responsible for this process are only partly known. Age-related muscle dysfunction is also a feature of aging in the fruit fly Drosophila melanogaster. Here we describe a detailed step-by-step protocol, which takes place over 3 d, for whole-mount immunostaining of Drosophila flight muscle. The skeletal muscle is fixed and permeabilized without any tissue freezing and dehydration so that antigens are accessible for staining with appropriate antibodies and the overall tissue ultrastructure is well preserved. This technique can be used to identify age-related cellular changes driving skeletal muscle aging and for characterizing models of human muscle disease in Drosophila.
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Affiliation(s)
- Liam C Hunt
- Department of Developmental Neurobiology, Division of Developmental Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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23
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Crossland H, Kazi AA, Lang CH, Timmons JA, Pierre P, Wilkinson DJ, Smith K, Szewczyk NJ, Atherton PJ. Focal adhesion kinase is required for IGF-I-mediated growth of skeletal muscle cells via a TSC2/mTOR/S6K1-associated pathway. Am J Physiol Endocrinol Metab 2013; 305:E183-93. [PMID: 23695213 PMCID: PMC3725543 DOI: 10.1152/ajpendo.00541.2012] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Focal adhesion kinase (FAK) is an attachment complex protein associated with the regulation of muscle mass through as-of-yet unclear mechanisms. We tested whether FAK is functionally important for muscle hypertrophy, with the hypothesis that FAK knockdown (FAK-KD) would impede cell growth associated with a trophic stimulus. C₂C₁₂ skeletal muscle cells harboring FAK-targeted (FAK-KD) or scrambled (SCR) shRNA were created using lentiviral transfection techniques. Both FAK-KD and SCR myotubes were incubated for 24 h with IGF-I (10 ng/ml), and additional SCR cells (±IGF-1) were incubated with a FAK kinase inhibitor before assay of cell growth. Muscle protein synthesis (MPS) and putative FAK signaling mechanisms (immunoblotting and coimmunoprecipitation) were assessed. IGF-I-induced increases in myotube width (+41 ± 7% vs. non-IGF-I-treated) and total protein (+44 ± 6%) were, after 24 h, attenuated in FAK-KD cells, whereas MPS was suppressed in FAK-KD vs. SCR after 4 h. These blunted responses were associated with attenuated IGF-I-induced FAK Tyr³⁹⁷ phosphorylation and markedly suppressed phosphorylation of tuberous sclerosis complex 2 (TSC2) and critical downstream mTOR signaling (ribosomal S6 kinase, eIF4F assembly) in FAK shRNA cells (all P < 0.05 vs. IGF-I-treated SCR cells). However, binding of FAK to TSC2 or its phosphatase Shp-2 was not affected by IGF-I or cell phenotype. Finally, FAK-KD-mediated suppression of cell growth was recapitulated by direct inhibition of FAK kinase activity in SCR cells. We conclude that FAK is required for IGF-I-induced muscle hypertrophy, signaling through a TSC2/mTOR/S6K1-dependent pathway via means requiring the kinase activity of FAK but not altered FAK-TSC2 or FAK-Shp-2 binding.
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MESH Headings
- Algorithms
- Animals
- Blotting, Western
- Cells, Cultured
- Focal Adhesion Protein-Tyrosine Kinases/antagonists & inhibitors
- Focal Adhesion Protein-Tyrosine Kinases/genetics
- Focal Adhesion Protein-Tyrosine Kinases/physiology
- Genetic Vectors
- Immunoprecipitation
- Insulin-Like Growth Factor I/physiology
- Lentivirus/genetics
- Mice
- Muscle Fibers, Skeletal/drug effects
- Muscle Fibers, Skeletal/physiology
- Muscle Fibers, Skeletal/ultrastructure
- Muscle, Skeletal/cytology
- Muscle, Skeletal/growth & development
- Phosphorylation/drug effects
- RNA Interference
- RNA, Small Interfering/genetics
- Ribosomal Protein S6 Kinases, 90-kDa/metabolism
- Ribosomal Protein S6 Kinases, 90-kDa/physiology
- Signal Transduction/physiology
- TOR Serine-Threonine Kinases/metabolism
- TOR Serine-Threonine Kinases/physiology
- Tuberous Sclerosis Complex 2 Protein
- Tumor Suppressor Proteins/metabolism
- Tumor Suppressor Proteins/physiology
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Affiliation(s)
- Hannah Crossland
- Medical Research Council-Arthritis Research United Kingdom Centre of Excellence for Musculoskeletal Ageing Research, School of Graduate Entry Medicine and Health, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
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24
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Domsch K, Ezzeddine N, Nguyen HT. Abba is an essential TRIM/RBCC protein to maintain the integrity of sarcomeric cytoarchitecture. J Cell Sci 2013; 126:3314-23. [PMID: 23729735 DOI: 10.1242/jcs.122366] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Organized sarcomeric striations are an evolutionarily conserved hallmark of functional skeletal muscles. Here, we demonstrate that the Drosophila Abba protein, a member of the TRIM/RBCC superfamily, has a pivotal regulatory role in maintaining proper sarcomeric cytoarchitecture during development and muscle usage. abba mutant embryos initially form muscles, but F-actin and Myosin striations become progressively disrupted when the muscles undergo growth and endure increased contractile forces during larval development. Abnormal Myosin aggregates and myofiber atrophy are also notable in the abba mutants. The larval defects result in compromised muscle function, and hence important morphogenetic events do not occur properly during pupation, leading to lethality. Abba is localized at larval Z-discs, and genetic evidence indicates that abba interacts with α-actinin, kettin/D-titin and mlp84B, genes that encode important Z-disc proteins for stable myofibrillar organization and optimal muscle function. RNAi experiments and ultrastructural analysis reveal that Abba has an additional crucial role in sarcomere maintenance in adult muscles. Abba is required to ensure the integrity and function of Z-discs and M-lines. Rescue experiments further show that Abba function is dependent upon its B-box/coiled-coil domain, NHL repeats and RING finger domain. The importance of these presumed protein-protein interactions and ubiquitin ligase-associated domains supports our hypothesis that Abba is needed for specific protein complex formation and stabilization at Z-discs and M-lines.
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Affiliation(s)
- Katrin Domsch
- Department of Biology, Division of Developmental Biology, Friedrich-Alexander University of Erlangen-Nürnberg, Staudtstrasse 5, 91058 Erlangen, Germany
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25
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Gribova V, Gauthier-Rouvière C, Albigès-Rizo C, Auzely-Velty R, Picart C. Effect of RGD functionalization and stiffness modulation of polyelectrolyte multilayer films on muscle cell differentiation. Acta Biomater 2013; 9:6468-80. [PMID: 23261924 DOI: 10.1016/j.actbio.2012.12.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 12/04/2012] [Accepted: 12/11/2012] [Indexed: 02/06/2023]
Abstract
Skeletal muscle tissue engineering holds promise for the replacement of muscle damaged by injury and for the treatment of muscle diseases. Although arginylglycylaspartic acid (RGD) substrates have been widely explored in tissue engineering, there have been no studies aimed at investigating the combined effects of RGD nanoscale presentation and matrix stiffness on myogenesis. In the present work we use polyelectrolyte multilayer films made of poly(L-lysine) (PLL) and poly(L-glutamic) acid (PGA) as substrates of tunable stiffness that can be functionalized by a RGD adhesive peptide to investigate important events in myogenesis, including adhesion, migration, proliferation and differentiation. C2C12 myoblasts were used as cellular models. RGD presentation on soft films and increasing film stiffness could both induce cell adhesion, but the integrins involved in adhesion were different in the case of soft and stiff films. Soft films with RGD peptide appeared to be the most appropriate substrate for myogenic differentiation, while the stiff PLL/PGA films induced significant cell migration and proliferation and inhibited myogenic differentiation. ROCK kinase was found to be involved in the myoblast response to the different films. Indeed, its inhibition was sufficient to rescue differentiation on stiff films, but no significant changes were observed on stiff films with the RGD peptide. These results suggest that different signaling pathways may be activated depending on the mechanical and biochemical properties of multilayer films. This study emphasizes the advantage of soft PLL/PGA films presenting the RGD peptide in terms of myogenic differentiation. This soft RGD-presenting film may be further used as a coating of various polymeric scaffolds for muscle tissue engineering.
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26
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Briñas L, Vassilopoulos S, Bonne G, Guicheney P, Bitoun M. Role of dynamin 2 in the disassembly of focal adhesions. J Mol Med (Berl) 2013; 91:803-9. [DOI: 10.1007/s00109-013-1040-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 04/03/2013] [Accepted: 04/08/2013] [Indexed: 11/29/2022]
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27
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Pronovost SM, Beckerle MC, Kadrmas JL. Elevated expression of the integrin-associated protein PINCH suppresses the defects of Drosophila melanogaster muscle hypercontraction mutants. PLoS Genet 2013; 9:e1003406. [PMID: 23555310 PMCID: PMC3610608 DOI: 10.1371/journal.pgen.1003406] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 02/07/2013] [Indexed: 01/05/2023] Open
Abstract
A variety of human diseases arise from mutations that alter muscle contraction. Evolutionary conservation allows genetic studies in Drosophila melanogaster to be used to better understand these myopathies and suggest novel therapeutic strategies. Integrin-mediated adhesion is required to support muscle structure and function, and expression of Integrin adhesive complex (IAC) proteins is modulated to adapt to varying levels of mechanical stress within muscle. Mutations in flapwing (flw), a catalytic subunit of myosin phosphatase, result in non-muscle myosin hyperphosphorylation, as well as muscle hypercontraction, defects in size, motility, muscle attachment, and subsequent larval and pupal lethality. We find that moderately elevated expression of the IAC protein PINCH significantly rescues flw phenotypes. Rescue requires PINCH be bound to its partners, Integrin-linked kinase and Ras suppressor 1. Rescue is not achieved through dephosphorylation of non-muscle myosin, suggesting a mechanism in which elevated PINCH expression strengthens integrin adhesion. In support of this, elevated expression of PINCH rescues an independent muscle hypercontraction mutant in muscle myosin heavy chain, MhcSamba1. By testing a panel of IAC proteins, we show specificity for PINCH expression in the rescue of hypercontraction mutants. These data are consistent with a model in which PINCH is present in limiting quantities within IACs, with increasing PINCH expression reinforcing existing adhesions or allowing for the de novo assembly of new adhesion complexes. Moreover, in myopathies that exhibit hypercontraction, strategic PINCH expression may have therapeutic potential in preserving muscle structure and function. A wide variety of diseases of the muscle are caused by mutations that alter either the actin and myosin contractile machinery or its regulation. One class of mutations of interest results in hypercontraction of the muscle—actin and myosin fibers contract, but cannot efficiently relax. We have used the fruit fly as a model to study these mutations because of the striking similarity of fly and human muscle and because of the many genetic techniques that are available in the fly. Using a genetic approach we identified a protein, PINCH, whose increased expression can rescue the defects observed in hypercontraction mutants. PINCH is a component of integrin adhesion complexes, responsible for anchoring cells in their environment. This suggests that strengthening the anchorage of muscles via PINCH may be an effective strategy to prevent or reduce the muscle damage that occurs in diseases of muscle hypercontraction.
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Affiliation(s)
- Stephen M. Pronovost
- Huntsman Cancer Institute, Departments of Biology and Oncological Sciences, University of Utah, Salt Lake City, Utah, United States of America
| | - Mary C. Beckerle
- Huntsman Cancer Institute, Departments of Biology and Oncological Sciences, University of Utah, Salt Lake City, Utah, United States of America
| | - Julie L. Kadrmas
- Huntsman Cancer Institute, Departments of Biology and Oncological Sciences, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail:
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28
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Abstract
Animals use gustatory information to assess the suitability of potential food sources and make critical decisions on what to consume. For example, the taste of sugar generally signals a potent dietary source of carbohydrates. However, the intensity of the sensory response to a particular sugar, or "sweetness," is not always a faithful reporter of its nutritional value, and recent evidence suggests that animals can sense the caloric content of food independently of taste. Here, we demonstrate that the vinegar fly Drosophila melanogaster uses both taste and calorie sensing to determine feeding choices, and that the relative contribution of each changes over time. Using the capillary feeder assay, we allowed flies to choose between sources of sugars that varied in their ratio of sweetness to caloric value. We found that flies initially consume sugars according to taste. However, over several hours their preference shifts toward the food source with higher caloric content. This behavioral shift occurs more rapidly following food deprivation and is modulated by cAMP and insulin signaling within neurons. Our results are consistent with the existence of a taste-independent calorie sensor in flies, and suggest that calorie-based reward modifies long-term feeding preferences.
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Pantoja M, Fischer KA, Ieronimakis N, Reyes M, Ruohola-Baker H. Genetic elevation of sphingosine 1-phosphate suppresses dystrophic muscle phenotypes in Drosophila. Development 2012; 140:136-46. [PMID: 23154413 DOI: 10.1242/dev.087791] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Duchenne muscular dystrophy is a lethal genetic disease characterized by the loss of muscle integrity and function over time. Using Drosophila, we show that dystrophic muscle phenotypes can be significantly suppressed by a reduction of wunen, a homolog of lipid phosphate phosphatase 3, which in higher animals can dephosphorylate a range of phospholipids. Our suppression analyses include assessing the localization of Projectin protein, a titin homolog, in sarcomeres as well as muscle morphology and functional movement assays. We hypothesize that wunen-based suppression is through the elevation of the bioactive lipid Sphingosine 1-phosphate (S1P), which promotes cell proliferation and differentiation in many tissues, including muscle. We confirm the role of S1P in suppression by genetically altering S1P levels via reduction of S1P lyase (Sply) and by upregulating the serine palmitoyl-CoA transferase catalytic subunit gene lace, the first gene in the de novo sphingolipid biosynthetic pathway and find that these manipulations also reduce muscle degeneration. Furthermore, we show that reduction of spinster (which encodes a major facilitator family transporter, homologs of which in higher animals have been shown to transport S1P) can also suppress dystrophic muscle degeneration. Finally, administration to adult flies of pharmacological agents reported to elevate S1P signaling significantly suppresses dystrophic muscle phenotypes. Our data suggest that localized intracellular S1P elevation promotes the suppression of muscle wasting in flies.
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Affiliation(s)
- Mario Pantoja
- Department of Biochemistry, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195, USA
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30
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Etheridge T, Oczypok EA, Lehmann S, Fields BD, Shephard F, Jacobson LA, Szewczyk NJ. Calpains mediate integrin attachment complex maintenance of adult muscle in Caenorhabditis elegans. PLoS Genet 2012; 8:e1002471. [PMID: 22253611 PMCID: PMC3257289 DOI: 10.1371/journal.pgen.1002471] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Accepted: 11/23/2011] [Indexed: 11/23/2022] Open
Abstract
Two components of integrin containing attachment complexes, UNC-97/PINCH and UNC-112/MIG-2/Kindlin-2, were recently identified as negative regulators of muscle protein degradation and as having decreased mRNA levels in response to spaceflight. Integrin complexes transmit force between the inside and outside of muscle cells and signal changes in muscle size in response to force and, perhaps, disuse. We therefore investigated the effects of acute decreases in expression of the genes encoding these multi-protein complexes. We find that in fully developed adult Caenorhabditis elegans muscle, RNAi against genes encoding core, and peripheral, members of these complexes induces protein degradation, myofibrillar and mitochondrial dystrophies, and a movement defect. Genetic disruption of Z-line– or M-line–specific complex members is sufficient to induce these defects. We confirmed that defects occur in temperature-sensitive mutants for two of the genes: unc-52, which encodes the extra-cellular ligand Perlecan, and unc-112, which encodes the intracellular component Kindlin-2. These results demonstrate that integrin containing attachment complexes, as a whole, are required for proper maintenance of adult muscle. These defects, and collapse of arrayed attachment complexes into ball like structures, are blocked when DIM-1 levels are reduced. Degradation is also blocked by RNAi or drugs targeting calpains, implying that disruption of integrin containing complexes results in calpain activation. In wild-type animals, either during development or in adults, RNAi against calpain genes results in integrin muscle attachment disruptions and consequent sub-cellular defects. These results demonstrate that calpains are required for proper assembly and maintenance of integrin attachment complexes. Taken together our data provide in vivo evidence that a calpain-based molecular repair mechanism exists for dealing with attachment complex disruption in adult muscle. Since C. elegans lacks satellite cells, this mechanism is intrinsic to the muscles and raises the question if such a mechanism also exists in higher metazoans. Muscle is a dynamic tissue that grows in response to use and nutrition and shrinks in response to lack of use, poor nutrition, or disease. Loss of muscle mass is an important public health problem, but we understand little of the genes that regulate muscle shrinkage. We have found that, in adult worm muscle, attachment to the basement membrane is continuously required to prevent catastrophic sub-cellular defects that result in impaired ability of muscle to function. We have also identified a group of proteases that are activated when the attachment fails to be properly maintained. Conversely, when these proteases are lacking in adult muscle, the muscles fail to maintain attachment to the basement membrane. Thus, we have discovered a group of proteases that appear to act to maintain attachment to the basement membrane and therefore to maintain muscle itself. Because these worms lack satellite cells, this maintenance system is intrinsic to muscle, thus raising the question whether a similar or identical system also works in humans.
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Affiliation(s)
- Timothy Etheridge
- School of Graduate Entry Medicine and Health, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
| | - Elizabeth A. Oczypok
- School of Graduate Entry Medicine and Health, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Susann Lehmann
- School of Graduate Entry Medicine and Health, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
| | - Brandon D. Fields
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Freya Shephard
- School of Graduate Entry Medicine and Health, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
| | - Lewis A. Jacobson
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Nathaniel J. Szewczyk
- School of Graduate Entry Medicine and Health, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
- * E-mail:
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31
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Xie X, Auld VJ. Integrins are necessary for the development and maintenance of the glial layers in the Drosophila peripheral nerve. Development 2011; 138:3813-22. [PMID: 21828098 DOI: 10.1242/dev.064816] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Peripheral nerve development involves multiple classes of glia that cooperate to form overlapping glial layers paired with the deposition of a surrounding extracellular matrix (ECM). The formation of this tubular structure protects the ensheathed axons from physical and pathogenic damage and from changes in the ionic environment. Integrins, a major family of ECM receptors, play a number of roles in the development of myelinating Schwann cells, one class of glia ensheathing the peripheral nerves of vertebrates. However, the identity and the role of the integrin complexes utilized by the other classes of peripheral nerve glia have not been determined in any animal. Here, we show that, in the peripheral nerves of Drosophila melanogaster, two integrin complexes (αPS2βPS and αPS3βPS) are expressed in the different glial layers and form adhesion complexes with integrin-linked kinase and Talin. Knockdown of the common beta subunit (βPS) using inducible RNAi in all glial cells results in lethality and glial defects. Analysis of integrin complex function in specific glial layers showed that loss of βPS in the outermost layer (the perineurial glia) results in a failure to wrap the nerve, a phenotype similar to that of Matrix metalloproteinase 2-mediated degradation of the ECM. Knockdown of βPS integrin in the innermost wrapping glia causes a loss of glial processes around axons. Together, our data suggest that integrins are employed in different glial layers to mediate the development and maintenance of the protective glial sheath in Drosophila peripheral nerves.
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Affiliation(s)
- Xiaojun Xie
- Department of Zoology, Cell and Developmental Biology, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
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32
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Celebi B, Mantovani D, Pineault N. Effects of extracellular matrix proteins on the growth of haematopoietic progenitor cells. Biomed Mater 2011; 6:055011. [PMID: 21931196 DOI: 10.1088/1748-6041/6/5/055011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Umbilical cord blood (UCB) transplantation and haematological recovery are currently limited by the amount of haematopoietic progenitor cells (HPCs) present in each unit. HPCs and haematopoietic stem cells (HSCs) normally interact with cells and extracellular matrix (ECM) proteins present within the endosteal and vascular niches. Hence, we investigated whether coating of culture surfaces with ECM proteins normally present in the marrow microenvironment could benefit the ex vivo expansion of HPCs. Towards this, collagen types I and IV (COL I and IV), laminin (LN) and fibronectin (FN) were tested individually or as component of two ECM-mix complexes. Individually, ECM proteins had both common and unique properties on the growth and differentiation of UCB CD34+ cells; some ECM proteins favoured the differentiation of some lineages over that of others (e.g. FN for erythroids), some the expansion of HPCs (e.g. LN and megakaryocyte (MK) progenitor) while others had less effects. Next, two ECM-mix complexes were tested; the first one contained all four ECM proteins (4ECMp), while the second 'basement membrane-like structure' was without COL I (3ECMp). Removal of COL I led to strong reductions in cell growth and HPCs expansion. Interestingly, the 4ECMp-mix complex reproducibly increased CD34+ (1.3-fold) and CD41+ (1.2-fold) cell expansions at day 6 (P < 0.05) versus control, and induced greater myeloid progenitor expansion (P < 0.05) than 3ECMp. In conclusion, these results suggest that optimization of BM ECM protein complexes could provide a better environment for the ex vivo expansion of haematopoietic progenitors than individual ECM protein.
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Affiliation(s)
- Betül Celebi
- Hema-Quebec, Research & Development Department, Quebec City, PQ, Canada
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33
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Clark KA, Lesage-Horton H, Zhao C, Beckerle MC, Swank DM. Deletion of Drosophila muscle LIM protein decreases flight muscle stiffness and power generation. Am J Physiol Cell Physiol 2011; 301:C373-82. [PMID: 21562304 DOI: 10.1152/ajpcell.00206.2010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Muscle LIM protein (MLP) can be found at the Z-disk of sarcomeres where it is hypothesized to be involved in sensing muscle stretch. Loss of murine MLP results in dilated cardiomyopathy, and mutations in human MLP lead to cardiac hypertrophy, indicating a critical role for MLP in maintaining normal cardiac function. Loss of MLP in Drosophila (mlp84B) also leads to muscle dysfunction, providing a model system to examine MLP's mechanism of action. Mlp84B-null flies that survive to adulthood are not able to fly or beat their wings. Transgenic expression of the mlp84B gene in the Mlp84B-null background rescues flight ability and restores wing beating ability. Mechanical analysis of skinned flight muscle fibers showed a 30% decrease in oscillatory power production and a slight increase in the frequency at which maximum power is generated for fibers lacking Mlp84B compared with rescued fibers. Mlp84B-null muscle fibers displayed a 25% decrease in passive, active, and rigor stiffness compared with rescued fibers, but no significant decrease in isometric tension generation was observed. Muscle ultrastructure of Mlp84B-null muscle fibers is grossly normal; however, the null fibers have a slight decrease, 11%, in thick filament number per unit cross-sectional area. Our data indicate that MLP contributes to muscle stiffness and is necessary for maximum work and power generation.
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Affiliation(s)
- Kathleen A Clark
- Department of Biology and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute,, Troy, NY 12180, USA
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34
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Phosphoinositide regulation of integrin trafficking required for muscle attachment and maintenance. PLoS Genet 2011; 7:e1001295. [PMID: 21347281 PMCID: PMC3037412 DOI: 10.1371/journal.pgen.1001295] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 01/06/2011] [Indexed: 12/21/2022] Open
Abstract
Muscles must maintain cell compartmentalization when remodeled during development and use. How spatially restricted adhesions are regulated with muscle remodeling is largely unexplored. We show that the myotubularin (mtm) phosphoinositide phosphatase is required for integrin-mediated myofiber attachments in Drosophila melanogaster, and that mtm-depleted myofibers exhibit hallmarks of human XLMTM myopathy. Depletion of mtm leads to increased integrin turnover at the sarcolemma and an accumulation of integrin with PI(3)P on endosomal-related membrane inclusions, indicating a role for Mtm phosphatase activity in endocytic trafficking. The depletion of Class II, but not Class III, PI3-kinase rescued mtm-dependent defects, identifying an important pathway that regulates integrin recycling. Importantly, similar integrin localization defects found in human XLMTM myofibers signify conserved MTM1 function in muscle membrane trafficking. Our results indicate that regulation of distinct phosphoinositide pools plays a central role in maintaining cell compartmentalization and attachments during muscle remodeling, and they suggest involvement of Class II PI3-kinase in MTM-related disease. Muscles require strong extracellular attachments to preserve cellular integrity during force-generating contractions. Integrin transmembrane receptors mediate muscle attachments at highly localized sites, but how this pattern of attachments is continuously maintained with muscle use is not understood. Human X-linked myotubular myopathy (XLMTM), a frequently fatal muscle disease, is associated with mutations in the MTM1 lipid regulator. Myotubularin (MTM) lipid phosphatases are implicated in endocytosis, a process of cellular uptake that can traffic transmembrane receptors for redelivery to the plasma membrane or to protein destruction. Here, we address MTM roles in muscle, using the genetically tractable fruit fly for detailed investigation of muscle cellular organization and functions. We show that fly muscle cells depleted for mtm function exhibit hallmarks of human XLMTM. We found that mtm regulates integrin localization through endocytosis and, in this role, is needed to maintain muscle attachments. Co-depletion of Class II PI3-kinase with mtm restores normal integrin localization at muscle attachment sites and fly survival, identifying a potential therapy target in MTM-related disease. Importantly, we show that integrin localization is also disrupted in human XLMTM. Our work shows conservation of MTM function in integrin trafficking and reveals insights into regulation of muscle cell maintenance and human disease.
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Stress and muscular dystrophy: a genetic screen for dystroglycan and dystrophin interactors in Drosophila identifies cellular stress response components. Dev Biol 2011; 352:228-42. [PMID: 21256839 DOI: 10.1016/j.ydbio.2011.01.013] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 01/11/2011] [Accepted: 01/12/2011] [Indexed: 11/24/2022]
Abstract
In Drosophila, like in humans, Dystrophin Glycoprotein Complex (DGC) deficiencies cause a life span shortening disease, associated with muscle dysfunction. We performed the first in vivo genetic interaction screen in ageing dystrophic muscles and identified genes that have not been shown before to have a role in the development of muscular dystrophy and interact with dystrophin and/or dystroglycan. Mutations in many of the found interacting genes cause age-dependent morphological and heat-induced physiological defects in muscles, suggesting their importance in the tissue. Majority of them is phylogenetically conserved and implicated in human disorders, mainly tumors and myopathies. Functionally they can be divided into three main categories: proteins involved in communication between muscle and neuron, and interestingly, in mechanical and cellular stress response pathways. Our data show that stress induces muscle degeneration and accelerates age-dependent muscular dystrophy. Dystrophic muscles are already compromised; and as a consequence they are less adaptive and more sensitive to energetic stress and to changes in the ambient temperature. However, only dystroglycan, but not dystrophin deficiency causes extreme myodegeneration induced by energetic stress suggesting that dystroglycan might be a component of the low-energy pathway and act as a transducer of energetic stress in normal and dystrophic muscles.
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36
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Spatial regulation of cell adhesion in the Drosophila wing is mediated by Delilah, a potent activator of βPS integrin expression. Dev Biol 2011; 351:99-109. [PMID: 21215259 DOI: 10.1016/j.ydbio.2010.12.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Revised: 12/16/2010] [Accepted: 12/20/2010] [Indexed: 01/04/2023]
Abstract
In spite of our conceptual view of how differential gene expression is used to define different cell identities, we still do not understand how different cell identities are translated into actual cell properties. The example discussed here is that of the fly wing, which is composed of two main cell types: vein and intervein cells. These two cell types differ in many features, including their adhesive properties. One of the major differences is that intervein cells express integrins, which are required for the attachment of the two wing layers to each other, whereas vein cells are devoid of integrin expression. The major signaling pathways that divide the wing to vein and intervein domains have been characterized. However, the genetic programs that execute these two alternative differentiation programs are still very roughly drawn. Here we identify the bHLH protein Delilah (Dei) as a mediator between signaling pathways that specify intervein cell-fate and one of the most significant realizators of this fate, βPS integrin. Dei's expression is restricted to intervein territories where it acts as a potent activator of βPS integrin expression. In the absence of normal Dei activity the level of βPS integrin is reduced, leading to a failure of adhesion between the dorsal and ventral wing layers and a consequent formation of wing blisters. The effect of Dei on βPS expression is not restricted to the wing, suggesting that Dei functions as a general genetic switch, which is turned on wherever a sticky cell-identity is determined and integrin-based adhesion is required.
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37
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Rui Y, Bai J, Perrimon N. Sarcomere formation occurs by the assembly of multiple latent protein complexes. PLoS Genet 2010; 6:e1001208. [PMID: 21124995 PMCID: PMC2987826 DOI: 10.1371/journal.pgen.1001208] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Accepted: 10/15/2010] [Indexed: 12/04/2022] Open
Abstract
The stereotyped striation of myofibrils is a conserved feature of muscle organization that is critical to its function. Although most components that constitute the basic myofibrils are well-characterized biochemically and are conserved across the animal kingdom, the mechanisms leading to the precise assembly of sarcomeres, the basic units of myofibrils, are poorly understood. To gain insights into this process, we investigated the functional relationships of sarcomeric protein complexes. Specifically, we systematically analyzed, using either RNAi in primary muscle cells or available genetic mutations, the organization of myofibrils in Drosophila muscles that lack one or more sarcomeric proteins. Our study reveals that the thin and thick filaments are mutually dependent on each other for striation. Further, the tension sensor complex comprised of zipper/Zasp/α-actinin is involved in stabilizing the sarcomere but not in its initial formation. Finally, integrins appear essential for the interdigitation of thin and thick filaments that occurs prior to striation. Thus, sarcomere formation occurs by the coordinated assembly of multiple latent protein complexes, as opposed to sequential assembly. Muscle functionality relies on the correct assembly of myofibrils, which are composed of tandem arrays of basic functional contractile units called the sarcomeres. Many mutations in genes encoding sarcomeric proteins cause muscle diseases such as congenital myopathy and dilated cardiac hypertrophy. Understanding the process of sarcomere assembly is not only relevant to the understanding of how protein complexes interact to form complex supra-molecular structures, but also of great significance to medicine for muscle diseases. Here, by taking advantage of our newly developed primary muscle cell culture method, we reevaluate sarcomere assembly by systematically analyzing the functional relationship of sarcomeric proteins using RNA interference or genetic ablation techniques. Our analysis leads us to propose a “two-state” model whereby sarcomeric proteins exist either in the “chaotic” state with independently assembled differential functional complexes or the “highly ordered suprastructure” state made from these complexes. Because we fail to detect any previously hypothesized sarcomere assembly intermediates in our system, our data support the model that sarcomere assembly is a highly coordinated process mediated by multiple latent protein complexes and does not occur in a step-wise fashion.
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Affiliation(s)
- Yanning Rui
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail: (YR); (NP)
| | - Jianwu Bai
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Norbert Perrimon
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail: (YR); (NP)
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38
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Distinct developmental roles for direct and indirect talin-mediated linkage to actin. Dev Biol 2010; 345:64-77. [PMID: 20599891 DOI: 10.1016/j.ydbio.2010.06.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Revised: 06/19/2010] [Accepted: 06/22/2010] [Indexed: 11/20/2022]
Abstract
Transmembrane adhesion receptors, such as integrins, mediate cell adhesion by interacting with intracellular proteins that connect to the cytoskeleton. Talin, one such linker protein, is essential to connect extracellular matrix-bound integrins to the cytoskeleton. Talin can connect to the cytoskeleton either directly, through its actin-binding motifs, or indirectly, by recruiting other actin-binding proteins. Talin's carboxy-terminal end contains a well-characterized actin-binding domain (ABD). We tested the role of the C-terminal ABD of talin in integrin function in Drosophila. We found that introduction of mutations that reduced actin binding in vitro into the isolated C-terminal Talin-ABD impaired actin binding in vivo. Moreover, when engineered into full-length talin, these mutations disrupted a subset of integrin-mediated adhesion-dependent developmental events. Specifically, morphogenetic processes that involve dynamic, short-term integrin-mediated adhesion were particularly sensitive to impaired function of the C-terminal Talin-ABD. We propose that during development talin connects integrins to the cytoskeleton in distinct ways in different types of integrin-mediated adhesion: directly in transient adhesions and indirectly in stable long-lasting adhesions. Our results provide insight into how a similar array of molecular components can contribute to diverse adhesive processes throughout development.
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39
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Yuan L, Fairchild MJ, Perkins AD, Tanentzapf G. Analysis of integrin turnover in fly myotendinous junctions. J Cell Sci 2010; 123:939-46. [PMID: 20179102 DOI: 10.1242/jcs.063040] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Transient (short-term) cell adhesion underlies dynamic processes such as cell migration, whereas stable (long-term) cell adhesion maintains tissue architecture. Ongoing adhesion complex turnover is essential for transient cell adhesion, but it is not known whether turnover is also required for maintenance of long-term adhesion. We used fluorescence recovery after photobleaching to analyze the dynamics of an integrin adhesion complex (IAC) in a model of long-term cell-ECM adhesion, myotendinous junctions (MTJs), in fly embryos and larvae. We found that the IAC undergoes turnover in MTJs and that this process is mediated by clathrin-dependent endocytosis. Moreover, the small GTPase Rab5 can regulate the proportion of IAC components that undergo turnover. Also, altering Rab5 activity weakened MTJs, resulting in muscle defects. In addition, growth of MTJs was concomitant with a decrease in the proportion of IAC components undergoing turnover. We propose that IAC turnover is tightly regulated in long-term cell-ECM adhesions to allow normal tissue growth and maintenance.
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Affiliation(s)
- Lin Yuan
- Department of Cellular and Physiological Sciences, University of British Columbia, Life Science Institute, 2350 Health Sciences Mall, Vancouver, British Columbia, Canada
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