scholarly journals Conventional and Non-Conventional Roles of Non-Muscle Myosin II-Actin in Neuronal Development and Degeneration

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1926
Author(s):  
Míriam Javier-Torrent ◽  
Carlos A. Saura
Keyword(s):  
Neuronal Development ◽  
Myosin Ii ◽  
Deep Understanding ◽  
Cellular Mechanisms ◽  
Cytoskeletal Dynamics ◽  
And Migration ◽  
Contractile Forces ◽  
Muscle Myosin ◽  
Actin Cytoskeletal Dynamics ◽  
The Brain

Myosins are motor proteins that use chemical energy to produce mechanical forces driving actin cytoskeletal dynamics. In the brain, the conventional non-muscle myosin II (NMII) regulates actin filament cytoskeletal assembly and contractile forces during structural remodeling of axons and dendrites, contributing to morphology, polarization, and migration of neurons during brain development. NMII isoforms also participate in neurotransmission and synaptic plasticity by driving actin cytoskeletal dynamics during synaptic vesicle release and retrieval, and formation, maturation, and remodeling of dendritic spines. NMIIs are expressed differentially in cerebral non-neuronal cells, such as microglia, astrocytes, and endothelial cells, wherein they play key functions in inflammation, myelination, and repair. Besides major efforts to understand the physiological functions and regulatory mechanisms of NMIIs in the nervous system, their contributions to brain pathologies are still largely unclear. Nonetheless, genetic mutations or deregulation of NMII and its regulatory effectors are linked to autism, schizophrenia, intellectual disability, and neurodegeneration, indicating non-conventional roles of NMIIs in cellular mechanisms underlying neurodevelopmental and neurodegenerative disorders. Here, we summarize the emerging biological roles of NMIIs in the brain, and discuss how actomyosin signaling contributes to dysfunction of neurons and glial cells in the context of neurological disorders. This knowledge is relevant for a deep understanding of NMIIs on the pathogenesis and therapeutics of neuropsychiatric and neurodegenerative diseases.

scholarly journals Mechanical bistability enabled by ectodermal compression facilitates Drosophila mesoderm invagination

2021 ◽  
Author(s):  
Hanqing Guo ◽  
Michael Swan ◽  
Shicheng Huang ◽  
Bing He
Keyword(s):  
Myosin Ii ◽  
Cell Sheet ◽  
Apical Surface ◽  
Apical Constriction ◽  
Out Of Plane ◽  
A Cell ◽  
Plane Compression ◽  
Contractile Forces ◽  
Tissue Relaxation ◽  
Muscle Myosin

Apical constriction driven by non-muscle myosin II (″myosin″) provides a well-conserved mechanism to mediate epithelial folding. It remains unclear how contractile forces near the apical surface of a cell sheet drive out-of-plane bending of the sheet and whether myosin contractility is required throughout folding. By optogenetic-mediated acute inhibition of myosin, we find that during Drosophila mesoderm invagination, myosin contractility is critical to prevent tissue relaxation during the early, ″priming″ stage of folding but is dispensable for the actual folding step after the tissue passes through a stereotyped transitional configuration, suggesting that the mesoderm is mechanically bistable during gastrulation. Combining computer modeling and experimental measurements, we show that the observed mechanical bistability arises from an in-plane compression from the surrounding ectoderm, which promotes mesoderm invagination by facilitating a buckling transition. Our results indicate that Drosophila mesoderm invagination requires a joint action of local apical constriction and global in-plane compression to trigger epithelial buckling.

scholarly journals α-Synuclein and Its A30P Mutant Affect Actin Cytoskeletal Structure and Dynamics

2009 ◽  
Vol 20 (16) ◽  
pp. 3725-3739 ◽  
Author(s):  
Vítor L. Sousa ◽  
Serena Bellani ◽  
Maila Giannandrea ◽  
Malikmohamed Yousuf ◽  
Flavia Valtorta ◽  
...  
Keyword(s):  
Hippocampal Neurons ◽  
Actin Polymerization ◽  
Wild Type ◽  
Cellular Processes ◽  
Cytoskeletal Dynamics ◽  
Endocytic Traffic ◽  
Actin Cytoskeletal Dynamics ◽  
Cytoskeletal Disruption ◽  
Familial Parkinson’S Disease ◽  
The Brain

The function of α-synuclein, a soluble protein abundant in the brain and concentrated at presynaptic terminals, is still undefined. Yet, α-synuclein overexpression and the expression of its A30P mutant are associated with familial Parkinson's disease. Working in cell-free conditions, in two cell lines as well as in primary neurons we demonstrate that α-synuclein and its A30P mutant have different effects on actin polymerization. Wild-type α-synuclein binds actin, slows down its polymerization and accelerates its depolymerization, probably by monomer sequestration; A30P mutant α-synuclein increases the rate of actin polymerization and disrupts the cytoskeleton during reassembly of actin filaments. Consequently, in cells expressing mutant α-synuclein, cytoskeleton-dependent processes, such as cell migration, are inhibited, while exo- and endocytic traffic is altered. In hippocampal neurons from mice carrying a deletion of the α-synuclein gene, electroporation of wild-type α-synuclein increases actin instability during remodeling, with growth of lamellipodia-like structures and apparent cell enlargement, whereas A30P α-synuclein induces discrete actin-rich foci during cytoskeleton reassembly. In conclusion, α-synuclein appears to play a major role in actin cytoskeletal dynamics and various aspects of microfilament function. Actin cytoskeletal disruption induced by the A30P mutant might alter various cellular processes and thereby play a role in the pathogenesis of neurodegeneration.

scholarly journals T-Plastin reinforces membrane protrusions to bridge matrix gaps during cell migration

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Damien Garbett ◽  
Anjali Bisaria ◽  
Changsong Yang ◽  
Dannielle G. McCarthy ◽  
Arnold Hayer ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Cell Migration ◽  
Actin Filaments ◽  
Myosin Ii ◽  
Adhesion Sites ◽  
Membrane Protrusions ◽  
And Migration ◽  
Muscle Myosin ◽  
Migrating Cells

Abstract Migrating cells move across diverse assemblies of extracellular matrix (ECM) that can be separated by micron-scale gaps. For membranes to protrude and reattach across a gap, actin filaments, which are relatively weak as single filaments, must polymerize outward from adhesion sites to push membranes towards distant sites of new adhesion. Here, using micropatterned ECMs, we identify T-Plastin, one of the most ancient actin bundling proteins, as an actin stabilizer that promotes membrane protrusions and enables bridging of ECM gaps. We show that T-Plastin widens and lengthens protrusions and is specifically enriched in active protrusions where F-actin is devoid of non-muscle myosin II activity. Together, our study uncovers critical roles of the actin bundler T-Plastin to promote protrusions and migration when adhesion is spatially-gapped.

scholarly journals Non-muscle myosin II takes centre stage in cell adhesion and migration

2009 ◽  
Vol 10 (11) ◽  
pp. 778-790 ◽  
Author(s):  
Miguel Vicente-Manzanares ◽  
Xuefei Ma ◽  
Robert S. Adelstein ◽  
Alan Rick Horwitz
Keyword(s):  
Cell Adhesion ◽  
Myosin Ii ◽  
Cell Adhesion And Migration ◽  
And Migration ◽  
Muscle Myosin

scholarly journals Distinct and redundant roles of the non-muscle myosin II isoforms and functional domains

2011 ◽  
Vol 39 (5) ◽  
pp. 1131-1135 ◽  
Author(s):  
Aibing Wang ◽  
Xuefei Ma ◽  
Mary Anne Conti ◽  
Robert S. Adelstein
Keyword(s):  
Actin Filaments ◽  
Myosin Ii ◽  
Neuronal Cell ◽  
Kinetic Properties ◽  
Neuroepithelial Cell ◽  
Cross Link ◽  
Muscle Myosin ◽  
The Brain ◽  
Cell Cell

We propose that the in vivo functions of NM II (non-muscle myosin II) can be divided between those that depend on the N-terminal globular motor domain and those less dependent on motor activity but more dependent on the C-terminal domain. The former, being more dependent on the kinetic properties of NM II to translocate actin filaments, are less amenable to substitution by different NM II isoforms, whereas the in vivo functions of the latter, which involve the structural properties of NM II to cross-link actin filaments, are more amenable to substitution. In light of this hypothesis, we examine the ability of NM II-A, as well as a motor-compromised form of NM II-B, to replace NM II-B and rescue neuroepithelial cell–cell adhesion defects and hydrocephalus in the brain of NM II-B-depleted mice. We also examine the ability of NM II-B as well as chimaeric forms of NM II (II-A head and II-B tail and vice versa) to substitute for NM II-A in cell–cell adhesions in II-A-ablated mice. However, we also show that certain functions, such as neuronal cell migration in the developing brain and vascularization of the mouse embryo and placenta, specifically require NM II-B and II-A respectively.

scholarly journals The localization and activity of sphingosine kinase 1 are coordinately regulated with actin cytoskeletal dynamics in macrophages. VOLUME 282 (2007) PAGES 23147-23162

2008 ◽  
Vol 283 (9) ◽  
pp. 5972
Author(s):  
David J. Kusner ◽  
Christopher R. Thompson ◽  
Natalie A. Melrose ◽  
Stuart M. Pitson ◽  
Lina M. Obeid ◽  
...  
Keyword(s):  
Sphingosine Kinase ◽  
Sphingosine Kinase 1 ◽  
Cytoskeletal Dynamics ◽  
Actin Cytoskeletal Dynamics

scholarly journals Bidirectional feedback between BCR signaling and actin cytoskeletal dynamics

FEBS Journal ◽  
2021 ◽  
Author(s):  
Anshuman Bhanja ◽  
Ivan Rey‐Suarez ◽  
Wenxia Song ◽  
Arpita Upadhyaya
Keyword(s):  
Bcr Signaling ◽  
Cytoskeletal Dynamics ◽  
Actin Cytoskeletal Dynamics

scholarly journals Neuron–Glia Interactions in Tuberous Sclerosis Complex Affect the Synaptic Balance in 2D and Organoid Cultures

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 134
Author(s):  
Stephanie Dooves ◽  
Arianne J. H. van Velthoven ◽  
Linda G. Suciati ◽  
Vivi M. Heine
Keyword(s):  
Tuberous Sclerosis ◽  
Glial Cells ◽  
Tuberous Sclerosis Complex ◽  
Neuronal Development ◽  
Transmembrane Proteins ◽  
Significant Burden ◽  
Epidermal Growth ◽  
And Control ◽  
Egf Signaling ◽  
The Brain

Tuberous sclerosis complex (TSC) is a genetic disease affecting the brain. Neurological symptoms like epilepsy and neurodevelopmental issues cause a significant burden on patients. Both neurons and glial cells are affected by TSC mutations. Previous studies have shown changes in the excitation/inhibition balance (E/I balance) in TSC. Astrocytes are known to be important for neuronal development, and astrocytic dysfunction can cause changes in the E/I balance. We hypothesized that astrocytes affect the synaptic balance in TSC. TSC patient-derived stem cells were differentiated into astrocytes, which showed increased proliferation compared to control astrocytes. RNA sequencing revealed changes in gene expression, which were related to epidermal growth factor (EGF) signaling and enriched for genes that coded for secreted or transmembrane proteins. Control neurons were cultured in astrocyte-conditioned medium (ACM) of TSC and control astrocytes. After culture in TSC ACM, neurons showed an altered synaptic balance, with an increase in the percentage of VGAT+ synapses. These findings were confirmed in organoids, presenting a spontaneous 3D organization of neurons and glial cells. To conclude, this study shows that TSC astrocytes are affected and secrete factors that alter the synaptic balance. As an altered E/I balance may underlie many of the neurological TSC symptoms, astrocytes may provide new therapeutic targets.

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