scholarly journals Caveolae internalization repairs wounded cells and muscle fibers

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Matthias Corrotte ◽  
Patricia E Almeida ◽  
Christina Tam ◽  
Thiago Castro-Gomes ◽  
Maria Cecilia Fernandes ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Muscle Fibers ◽  
Mechanistic Explanation ◽  
Cell Types ◽  
Underlying Mechanism ◽  
Acid Sphingomyelinase ◽  
Muscle Pathology ◽  
Dystrophic Muscle ◽  
Cellular Survival ◽  
Membrane Resealing

Rapid repair of plasma membrane wounds is critical for cellular survival. Muscle fibers are particularly susceptible to injury, and defective sarcolemma resealing causes muscular dystrophy. Caveolae accumulate in dystrophic muscle fibers and caveolin and cavin mutations cause muscle pathology, but the underlying mechanism is unknown. Here we show that muscle fibers and other cell types repair membrane wounds by a mechanism involving Ca2+-triggered exocytosis of lysosomes, release of acid sphingomyelinase, and rapid lesion removal by caveolar endocytosis. Wounding or exposure to sphingomyelinase triggered endocytosis and intracellular accumulation of caveolar vesicles, which gradually merged into larger compartments. The pore-forming toxin SLO was directly visualized entering cells within caveolar vesicles, and depletion of caveolin inhibited plasma membrane resealing. Our findings directly link lesion removal by caveolar endocytosis to the maintenance of plasma membrane and muscle fiber integrity, providing a mechanistic explanation for the muscle pathology associated with mutations in caveolae proteins.

scholarly journals Exocytosis of acid sphingomyelinase by wounded cells promotes endocytosis and plasma membrane repair

2010 ◽  
Vol 189 (6) ◽  
pp. 1027-1038 ◽  
Author(s):  
Christina Tam ◽  
Vincent Idone ◽  
Cecilia Devlin ◽  
Maria Cecilia Fernandes ◽  
Andrew Flannery ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Lysosomal Enzyme ◽  
Membrane Integrity ◽  
Acid Sphingomyelinase ◽  
Membrane Repair ◽  
Membrane Injury ◽  
Cellular Survival ◽  
Plasma Membrane Repair ◽  
Membrane Resealing ◽  
Niemann Pick

Rapid plasma membrane resealing is essential for cellular survival. Earlier studies showed that plasma membrane repair requires Ca2+-dependent exocytosis of lysosomes and a rapid form of endocytosis that removes membrane lesions. However, the functional relationship between lysosomal exocytosis and the rapid endocytosis that follows membrane injury is unknown. In this study, we show that the lysosomal enzyme acid sphingomyelinase (ASM) is released extracellularly when cells are wounded in the presence of Ca2+. ASM-deficient cells, including human cells from Niemann-Pick type A (NPA) patients, undergo lysosomal exocytosis after wounding but are defective in injury-dependent endocytosis and plasma membrane repair. Exogenously added recombinant human ASM restores endocytosis and resealing in ASM-depleted cells, suggesting that conversion of plasma membrane sphingomyelin to ceramide by this lysosomal enzyme promotes lesion internalization. These findings reveal a molecular mechanism for restoration of plasma membrane integrity through exocytosis of lysosomes and identify defective plasma membrane repair as a possible component of the severe pathology observed in NPA patients.

scholarly journals Degenerative and regenerative pathways underlying Duchenne muscular dystrophy revealed by single-nucleus RNA sequencing

2020 ◽  
Vol 117 (47) ◽  
pp. 29691-29701 ◽  
Author(s):  
Francesco Chemello ◽  
Zhaoning Wang ◽  
Hui Li ◽  
John R. McAnally ◽  
Ning Liu ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Dystrophin Gene ◽  
Cell Types ◽  
Muscle Pathology ◽  
Dystrophic Muscle ◽  
Nonmuscle Cell ◽  
Prevalent Disease ◽  
Single Nucleus ◽  
Muscle Disorder

Duchenne muscular dystrophy (DMD) is a fatal muscle disorder characterized by cycles of degeneration and regeneration of multinucleated myofibers and pathological activation of a variety of other muscle-associated cell types. The extent to which different nuclei within the shared cytoplasm of a myofiber may display transcriptional diversity and whether individual nuclei within a multinucleated myofiber might respond differentially to DMD pathogenesis is unknown. Similarly, the potential transcriptional diversity among nonmuscle cell types within dystrophic muscle has not been explored. Here, we describe the creation of a mouse model of DMD caused by deletion of exon 51 of the dystrophin gene, which represents a prevalent disease-causing mutation in humans. To understand the transcriptional abnormalities and heterogeneity associated with myofiber nuclei, as well as other mononucleated cell types that contribute to the muscle pathology associated with DMD, we performed single-nucleus transcriptomics of skeletal muscle of mice with dystrophin exon 51 deletion. Our results reveal distinctive and previously unrecognized myonuclear subtypes within dystrophic myofibers and uncover degenerative and regenerative transcriptional pathways underlying DMD pathogenesis. Our findings provide insights into the molecular underpinnings of DMD, controlled by the transcriptional activity of different types of muscle and nonmuscle nuclei.

scholarly journals Staphylococcus aureus α-toxin induces acid sphingomyelinase release from a human endothelial cell line

2021 ◽  
Author(s):  
David Krones ◽  
Marcel Rühling ◽  
Katrin Anne Becker ◽  
Tobias C. Kunz ◽  
Carolin Sehl ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Endothelial Cells ◽  
Plasma Membrane ◽  
Extracellular Fluid ◽  
Fluid Phase ◽  
Cell Types ◽  
Acid Sphingomyelinase ◽  
Host Cells ◽  
Membrane Repair ◽  
Membrane Area

AbstractStaphylococcus aureus (S. aureus) is well known to express a plethora of toxins of which the pore-forming hemolysin A (α-toxin) is the best-studied cytolysin. Pore-forming toxins (PFT) permeabilize host membranes during infection thereby causing concentration-dependent effects in host cell membranes ranging from disordered ion fluxes to cytolysis. Host cells possess defense mechanisms against PFT attack, resulting in endocytosis of the breached membrane area and delivery of repair vesicles to the insulted plasma membrane as well as a concurrent release of membrane repair enzymes. Since PFTs from several pathogens have been shown to recruit membrane repair components, we here investigated whether staphylococcal α-toxin is able to induce these mechanisms in endothelial cells. We show that S. aureus α-toxin induced increase in cytosolic Ca2+ in endothelial cells, which was accompanied by p38 MAPK phosphorylation. Toxin challenge led to increased endocytosis of an extracellular fluid phase marker as well as increased externalization of LAMP1-positive membranes suggesting that peripheral lysosomes are recruited to the insulted plasma membrane. We further observed that thereby the lysosomal protein acid sphingomyelinase (ASM) was released into the cell culture medium. Thus, our results show that staphylococcal α-toxin triggers mechanisms in endothelial cells, which have been implicated in membrane repair after damage of other cell types by different toxins.

scholarly journals Staphylococcus aureus α-Toxin Induces Acid Sphingomyelinase Release From a Human Endothelial Cell Line

2021 ◽  
Vol 12 ◽  
Author(s):  
David Krones ◽  
Marcel Rühling ◽  
Katrin Anne Becker ◽  
Tobias C. Kunz ◽  
Carolin Sehl ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Endothelial Cells ◽  
Plasma Membrane ◽  
Extracellular Fluid ◽  
Fluid Phase ◽  
Cell Types ◽  
Acid Sphingomyelinase ◽  
Host Cells ◽  
Membrane Repair ◽  
Membrane Area

Staphylococcus aureus (S. aureus) is well known to express a plethora of toxins of which the pore-forming hemolysin A (α-toxin) is the best-studied cytolysin. Pore-forming toxins (PFT) permeabilize host membranes during infection thereby causing concentration-dependent effects in host cell membranes ranging from disordered ion fluxes to cytolysis. Host cells possess defense mechanisms against PFT attack, resulting in endocytosis of the breached membrane area and delivery of repair vesicles to the insulted plasma membrane as well as a concurrent release of membrane repair enzymes. Since PFTs from several pathogens have been shown to recruit membrane repair components, we here investigated whether staphylococcal α-toxin is able to induce these mechanisms in endothelial cells. We show that S. aureus α-toxin induced increase in cytosolic Ca2+ in endothelial cells, which was accompanied by p38 MAPK phosphorylation. Toxin challenge led to increased endocytosis of an extracellular fluid phase marker as well as increased externalization of LAMP1-positive membranes suggesting that peripheral lysosomes are recruited to the insulted plasma membrane. We further observed that thereby the lysosomal protein acid sphingomyelinase (ASM) was released into the cell culture medium. Thus, our results show that staphylococcal α-toxin triggers mechanisms in endothelial cells, which have been implicated in membrane repair after damage of other cell types by different toxins.

scholarly journals An actin-dependent annexin complex mediates plasma membrane repair in muscle

2016 ◽  
Vol 213 (6) ◽  
pp. 705-718 ◽  
Author(s):  
Alexis R. Demonbreun ◽  
Mattia Quattrocelli ◽  
David Y. Barefield ◽  
Madison V. Allen ◽  
Kaitlin E. Swanson ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Muscle Fibers ◽  
Membrane Repair ◽  
Muscle Plasma Membrane ◽  
Shoulder Region ◽  
Plasma Membrane Repair ◽  
Molecular Machinery ◽  
Membrane Resealing ◽  
Efficient Recovery ◽  
High Resolution Microscopy

Disruption of the plasma membrane often accompanies cellular injury, and in muscle, plasma membrane resealing is essential for efficient recovery from injury. Muscle contraction, especially of lengthened muscle, disrupts the sarcolemma. To define the molecular machinery that directs repair, we applied laser wounding to live mammalian myofibers and assessed translocation of fluorescently tagged proteins using high-resolution microscopy. Within seconds of membrane disruption, annexins A1, A2, A5, and A6 formed a tight repair “cap.” Actin was recruited to the site of damage, and annexin A6 cap formation was both actin dependent and Ca2+ regulated. Repair proteins, including dysferlin, EHD1, EHD2, MG53, and BIN1, localized adjacent to the repair cap in a “shoulder” region enriched with phosphatidlyserine. Dye influx into muscle fibers lacking both dysferlin and the related protein myoferlin was substantially greater than control or individual null muscle fibers, underscoring the importance of shoulder-localized proteins. These data define the cap and shoulder as subdomains within the repair complex accumulating distinct and nonoverlapping components.

Membrane microdomains: lessons from microscopy

1995 ◽  
Vol 53 ◽  
pp. 776-777
Author(s):  
J.M. Robinson ◽  
J.M Oliver
Keyword(s):  
Spatial Distribution ◽  
Plasma Membrane ◽  
Epithelial Cells ◽  
Plasma Membranes ◽  
Cell Types ◽  
Imaging Modalities ◽  
Membrane Microdomains ◽  
Membrane Domains ◽  
Lateral Heterogeneity ◽  
Functional Importance

Specialized regions of plasma membranes displaying lateral heterogeneity are the focus of this Symposium. Specialized membrane domains are known for certain cell types such as differentiated epithelial cells where lateral heterogeneity in lipids and proteins exists between the apical and basolateral portions of the plasma membrane. Lateral heterogeneity and the presence of microdomains in membranes that are uniform in appearance have been more difficult to establish. Nonetheless a number of studies have provided evidence for membrane microdomains and indicated a functional importance for these structures.This symposium will focus on the use of various imaging modalities and related approaches to define membrane microdomains in a number of cell types. The importance of existing as well as emerging imaging technologies for use in the elucidation of membrane microdomains will be highlighted. The organization of membrane microdomains in terms of dimensions and spatial distribution is of considerable interest and will be addressed in this Symposium.

scholarly journals Inner Ear and Muscle Developmental Defects in Smpx-Deficient Zebrafish Embryos

2021 ◽  
Vol 22 (12) ◽  
pp. 6497
Author(s):  
Anna Ghilardi ◽  
Alberto Diana ◽  
Renato Bacchetta ◽  
Nadia Santo ◽  
Miriam Ascagni ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Hair Cells ◽  
Muscle Fibers ◽  
Underlying Mechanism ◽  
Loss Of Function ◽  
Zebrafish Model ◽  
Developmental Defects ◽  
Inner Ear Development ◽  
Syndromic Hearing Loss

The last decade has witnessed the identification of several families affected by hereditary non-syndromic hearing loss (NSHL) caused by mutations in the SMPX gene and the loss of function has been suggested as the underlying mechanism. In the attempt to confirm this hypothesis we generated an Smpx-deficient zebrafish model, pointing out its crucial role in proper inner ear development. Indeed, a marked decrease in the number of kinocilia together with structural alterations of the stereocilia and the kinocilium itself in the hair cells of the inner ear were observed. We also report the impairment of the mechanotransduction by the hair cells, making SMPX a potential key player in the construction of the machinery necessary for sound detection. This wealth of evidence provides the first possible explanation for hearing loss in SMPX-mutated patients. Additionally, we observed a clear muscular phenotype consisting of the defective organization and functioning of muscle fibers, strongly suggesting a potential role for the protein in the development of muscle fibers. This piece of evidence highlights the need for more in-depth analyses in search for possible correlations between SMPX mutations and muscular disorders in humans, thus potentially turning this non-syndromic hearing loss-associated gene into the genetic cause of dysfunctions characterized by more than one symptom, making SMPX a novel syndromic gene.

scholarly journals The exosome journey: from biogenesis to uptake and intracellular signalling

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Sonam Gurung ◽  
Dany Perocheau ◽  
Loukia Touramanidou ◽  
Julien Baruteau
Keyword(s):  
Clinical Trials ◽  
Plasma Membrane ◽  
Scientific Community ◽  
Cell Types ◽  
Clinical Applications ◽  
Clinical Development ◽  
Intracellular Signalling ◽  
Clinical Settings ◽  
Health And Disease ◽  
Adequate Definition

AbstractThe use of exosomes in clinical settings is progressively becoming a reality, as clinical trials testing exosomes for diagnostic and therapeutic applications are generating remarkable interest from the scientific community and investors. Exosomes are small extracellular vesicles secreted by all cell types playing intercellular communication roles in health and disease by transferring cellular cargoes such as functional proteins, metabolites and nucleic acids to recipient cells. An in-depth understanding of exosome biology is therefore essential to ensure clinical development of exosome based investigational therapeutic products. Here we summarise the most up-to-date knowkedge about the complex biological journey of exosomes from biogenesis and secretion, transport and uptake to their intracellular signalling. We delineate the major pathways and molecular players that influence each step of exosome physiology, highlighting the routes of interest, which will be of benefit to exosome manipulation and engineering. We highlight the main controversies in the field of exosome research: their adequate definition, characterisation and biogenesis at plasma membrane. We also delineate the most common identified pitfalls affecting exosome research and development. Unravelling exosome physiology is key to their ultimate progression towards clinical applications.

scholarly journals Plasma membrane integrity in health and disease: significance and therapeutic potential

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Catarina Dias ◽  
Jesper Nylandsted
Keyword(s):  
Plasma Membrane ◽  
Therapeutic Potential ◽  
Calcium Influx ◽  
Membrane Integrity ◽  
Cell Types ◽  
Physical Parameters ◽  
Membrane Repair ◽  
Plasma Membrane Integrity ◽  
Repair Mechanisms ◽  
And Function

AbstractMaintenance of plasma membrane integrity is essential for normal cell viability and function. Thus, robust membrane repair mechanisms have evolved to counteract the eminent threat of a torn plasma membrane. Different repair mechanisms and the bio-physical parameters required for efficient repair are now emerging from different research groups. However, less is known about when these mechanisms come into play. This review focuses on the existence of membrane disruptions and repair mechanisms in both physiological and pathological conditions, and across multiple cell types, albeit to different degrees. Fundamentally, irrespective of the source of membrane disruption, aberrant calcium influx is the common stimulus that activates the membrane repair response. Inadequate repair responses can tip the balance between physiology and pathology, highlighting the significance of plasma membrane integrity. For example, an over-activated repair response can promote cancer invasion, while the inability to efficiently repair membrane can drive neurodegeneration and muscular dystrophies. The interdisciplinary view explored here emphasises the widespread potential of targeting plasma membrane repair mechanisms for therapeutic purposes.

scholarly journals Treatment with rGDF11 does not improve the dystrophic muscle pathology of mdx mice

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Fabrizio Rinaldi ◽  
Yu Zhang ◽  
Ricardo Mondragon-Gonzalez ◽  
Jeffrey Harvey ◽  
Rita C. R. Perlingeiro
Keyword(s):  
Muscle Pathology ◽  
Mdx Mice ◽  
Dystrophic Muscle
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