scholarly journals Fluorescence-Based Analysis of Noncanonical Functions of Aminoacyl-tRNA Synthetase-Interacting Multifunctional Proteins (AIMPs) in Peripheral Nerves

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1064
Author(s):  
Muwoong Kim ◽  
Hyosun Kim ◽  
Dokyoung Kim ◽  
Chan Park ◽  
Youngbuhm Huh ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Schwann Cells ◽  
Myelin Sheath ◽  
Peripheral Nerves ◽  
Trna Synthetase ◽  
Ventral Horn ◽  
Nerve Degeneration ◽  
Aminoacyl Trna Synthetase ◽  
Multifunctional Proteins ◽  
Sheath Formation

Aminoacyl-tRNA synthetase-interacting multifunctional proteins (AIMPs) are auxiliary factors involved in protein synthesis related to aminoacyl-tRNA synthetases (ARSs). AIMPs, which are well known as nonenzymatic factors, include AIMP1/p43, AIMP2/p38, and AIMP3/p18. The canonical functions of AIMPs include not only protein synthesis via multisynthetase complexes but also maintenance of the structural stability of these complexes. Several recent studies have demonstrated nontypical (noncanonical) functions of AIMPs, such as roles in apoptosis, inflammatory processes, DNA repair, and so on. However, these noncanonical functions of AIMPs have not been studied in peripheral nerves related to motor and sensory functions. Peripheral nerves include two types of structures: peripheral axons and Schwann cells. The myelin sheath formed by Schwann cells produces saltatory conduction, and these rapid electrical signals control motor and sensory functioning in the service of survival in mammals. Schwann cells play roles not only in myelin sheath formation but also as modulators of nerve degeneration and regeneration. Therefore, it is important to identify the main functions of Schwann cells in peripheral nerves. Here, using immunofluorescence technique, we demonstrated that AIMPs are essential morphological indicators of peripheral nerve degeneration, and their actions are limited to peripheral nerves and not the dorsal root ganglion and the ventral horn of the spinal cord.

scholarly journals ATP Release through Lysosomal Exocytosis from Peripheral Nerves: The Effect of Lysosomal Exocytosis on Peripheral Nerve Degeneration and Regeneration after Nerve Injury

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Junyang Jung ◽  
Hyun Woo Jo ◽  
Hyunseob Kwon ◽  
Na Young Jeong
Keyword(s):  
Peripheral Nerve ◽  
Schwann Cells ◽  
Nerve Injury ◽  
Peripheral Nerves ◽  
Wallerian Degeneration ◽  
Atp Release ◽  
Nerve Degeneration ◽  
Peripheral Neurons ◽  
Charcot Marie Tooth Disease ◽  
Axonal Degradation

Studies have shown that lysosomal activation increases in Schwann cells after nerve injury. Lysosomal activation is thought to promote the engulfment of myelin debris or fragments of injured axons in Schwann cells during Wallerian degeneration. However, a recent interpretation of lysosomal activation proposes a different view of the phenomenon. During Wallerian degeneration, lysosomes become secretory vesicles and are activated for lysosomal exocytosis. The lysosomal exocytosis triggers adenosine 5′-triphosphate (ATP) release from peripheral neurons and Schwann cells during Wallerian degeneration. Exocytosis is involved in demyelination and axonal degradation, which facilitate nerve regeneration following nerve degeneration. At this time, released ATP may affect the communication between cells in peripheral nerves. In this review, our description of the relationship between lysosomal exocytosis and Wallerian degeneration has implications for the understanding of peripheral nerve degenerative diseases and peripheral neuropathies, such as Charcot-Marie-Tooth disease or Guillain-Barré syndrome.

scholarly journals Translation of myelin basic protein mRNA in oligodendrocytes is regulated by integrin activation and hnRNP-K

2011 ◽  
Vol 192 (5) ◽  
pp. 797-811 ◽  
Author(s):  
Lisbeth S. Laursen ◽  
Colin W. Chan ◽  
Charles ffrench-Constant
Keyword(s):  
Protein Synthesis ◽  
Myelin Basic Protein ◽  
Myelin Sheath ◽  
Basic Protein ◽  
Inhibitory Effect ◽  
Integrin Activation ◽  
Hnrnp K ◽  
Sheath Formation ◽  
The Central Nervous System ◽  
Mrna Binding

Myelination in the central nervous system provides a unique example of how cells establish asymmetry. The myelinating cell, the oligodendrocyte, extends processes to and wraps multiple axons of different diameter, keeping the number of wraps proportional to the axon diameter. Local regulation of protein synthesis represents one mechanism used to control the different requirements for myelin sheath at each axo–glia interaction. Prior work has established that β1-integrins are involved in the axoglial interactions that initiate myelination. Here, we show that integrin activation regulates translation of a key sheath protein, myelin basic protein (MBP), by reversing the inhibitory effect of the mRNA 3′UTR. During oligodendrocyte differentiation and myelination α6β1-integrin interacts with hnRNP-K, an mRNA-binding protein, which binds to MBP mRNA and translocates from the nucleus to the myelin sheath. Furthermore, knockdown of hnRNP-K inhibits MBP protein synthesis during myelination. Together, these results identify a novel pathway by which axoglial adhesion molecules coordinate MBP synthesis with myelin sheath formation.

scholarly journals Engineered Aminoacyl-tRNA Synthetase for Cell-Selective Analysis of Mammalian Protein Synthesis

2016 ◽  
Vol 138 (13) ◽  
pp. 4278-4281 ◽  
Author(s):  
Alborz Mahdavi ◽  
Graham D. Hamblin ◽  
Granton A. Jindal ◽  
John D. Bagert ◽  
Cathy Dong ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Trna Synthetase ◽  
Aminoacyl Trna Synthetase ◽  
Selective Analysis ◽  
Mammalian Protein

scholarly journals Breast schwannoma – a rare entity

Mastology ◽  
2020 ◽  
Vol 30 (Suppl 1) ◽  
Author(s):  
Juliana Lopes de Aguiar Araujo ◽  
Ubiratan Wagner de Sousa ◽  
Ana Tereza Diniz Marinho de França ◽  
Lourdes Maria Dantas de Góis
Keyword(s):  
Skin Lesion ◽  
Schwann Cells ◽  
Myelin Sheath ◽  
Peripheral Nerves ◽  
Cellular Proliferation ◽  
Benign Tumor ◽  
Spindle Cell ◽  
Surgical Excision ◽  
Metaplastic Carcinoma ◽  
Spindle Cell Neoplasm

Introduction: Schwannoma is a benign tumor originating from Schwann cells present in the myelin sheath of peripheral nerves. Breast presentation is rare, and its clinical manifestation can mimic that of breast carcinoma. Objectives: To report the case of a patient with breast Schwannoma. Method/Case report: T.S.L., 14 years old, presented a nodule in the left breast (LB) with local growth for 2 months. Ultrasound (US) revealed a cystic formation in the lower outer quadrant of 1.8x1.3 cm, BI-RADS 2. Physical examination indicated a nodular skin lesion next to the LB fold, with 2 cm at 5 h, 7 cm from the nipple. After the surgical excision of the nodule, anatomopathological examination showed a spindle cell neoplasm without nodular-pattern atypia or malignancy characteristics. Immunohistochemistry (IHC) confirmed the Schwannoma diagnosis. Considering this scenario, annual control was started, and the patient has no evidence of the disease after 5 years of diagnosis. Results/Discussion: Schwannoma is a typically benign tumor originating from Schwann cells in the myelin sheath of the nerves. It may result from the parasympathetic or sympathetic division of the autonomic nervous system of the organ. It is one of the few truly encapsulated tumors of the human body and almost always solitary. It is usually located in the trunk, flexor surfaces, retroperitoneum, and rarely in the breast, representing approximately 2.6% of Schwannoma cases. It affects individuals aged 30 to 50 years, with equal incidence in both men and women. The skin lesion presents as a sessile, asymptomatic nodule of 1–3 cm and slow growth. Pain and sensitivity may be present when tumor growth causes nerve compression. Mammography (MMG) shows well-circumscribed opacity, with a density similar to that of soft tissue. US usually reveals well-defined, hypoechoic, solid lesions and can include the target sign, posterior acoustic enhancement, and continuity with peripheral nerves. The definitive diagnosis is made histologically, and the differential diagnosis involves other spindle cell neoplasms, such as fibroadenoma, phyllodes tumor, leiomyoma, fibromatosis, and, rarely, metaplastic carcinoma. Fine-needle aspiration biopsy (FNAB) showed palisading fibrillar cells with non-atypical spindle-shaped nuclei forming Verocay bodies. IHC indicates intense and uniform expression of S-100 protein. Malignant transformation occurs in 3–10% of cases, with high cellular proliferation, atypical mitotic activity, cellular and nuclear pleomorphism, and foci of necrosis. The treatment of choice is surgical excision of the lesion. Tumor recurrence is low and associated with the mitotic index. Conclusion: The case reported and publications found bring to light the discussion on diagnosis and treatment of breast Schwannoma, a rare and benign neoplasm in this location.

scholarly journals Preparation of Enhanced Orthogonal Aminoacyl-tRNA-Synthetase v1

2020 ◽  
Author(s):  
Anne Zemella ◽  
Theresa Richter ◽  
Lena Thoring ◽  
Stefan Kubick
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Membrane Proteins ◽  
Trna Synthetase ◽  
Fluorescent Labeling ◽  
Laser Scanning Microscopy ◽  
Aminoacyl Trna Synthetase ◽  
Free Protein ◽  
Canonical Amino Acid ◽  
Cell Free Protein Synthesis

This is part 3.1 of the "A Combined Cell-Free Protein Synthesis and Fluorescence-Based Approach to Investigate GPCR Binding Properties" collection of protocols: https://www.protocols.io/view/a-combined-cell-free-protein-synthesis-and-fluores-bqntmven Collection Abstract: Fluorescent labeling of de novo synthesized proteins is in particular a valuable tool for functional and structural studies of membrane proteins. In this context, we present two methods for the site-specific fluorescent labeling of difficult-to-express membrane proteins in combination with cell-free protein synthesis. The cell-free protein synthesis system is based on Chinese Hamster Ovary Cells (CHO) since this system contains endogenous membrane structures derived from the endoplasmic reticulum. These so-called microsomes enable a direct integration of membrane proteins into a biological membrane. In this protocol the first part describes the fluorescent labeling by using a precharged tRNA, loaded with a fluorescent amino acid. The second part describes the preparation of a modified aminoacyl-tRNA-synthetase and a suppressor tRNA that are applied to the CHO cell-free system to enable the incorporation of a non-canonical amino acid. The reactive group of the non-canonical amino acid is further coupled to a fluorescent dye. Both methods utilize the amber stop codon suppression technology. The successful fluorescent labeling of the model G protein-coupled receptor adenosine A2A (Adora2a) is analyzed by in-gel-fluorescence, a reporter protein assay, and confocal laser scanning microscopy (CLSM). Moreover, a ligand-dependent conformational change of the fluorescently labeled Adora2a was analyzed by bioluminescence resonance energy transfer (BRET). For Introduction and Notes, please see: https://www.protocols.io/view/a-combined-cell-free-protein-synthesis-and-fluores-bqntmven/guidelines

scholarly journals Myosin II has distinct functions in PNS and CNS myelin sheath formation

2008 ◽  
Vol 182 (6) ◽  
pp. 1171-1184 ◽  
Author(s):  
Haibo Wang ◽  
Ambika Tewari ◽  
Steven Einheber ◽  
James L. Salzer ◽  
Carmen V. Melendez-Vasquez
Keyword(s):  
Nervous System ◽  
Schwann Cells ◽  
Myelin Sheath ◽  
Actin Polymerization ◽  
Myosin Ii ◽  
Myelin Formation ◽  
Sheath Formation ◽  
Central Nervous Systems ◽  
Glial Membrane ◽  
Cytoskeleton Dynamics

The myelin sheath forms by the spiral wrapping of a glial membrane around the axon. The mechanisms responsible for this process are unknown but are likely to involve coordinated changes in the glial cell cytoskeleton. We have found that inhibition of myosin II, a key regulator of actin cytoskeleton dynamics, has remarkably opposite effects on myelin formation by Schwann cells (SC) and oligodendrocytes (OL). Myosin II is necessary for initial interactions between SC and axons, and its inhibition or down-regulation impairs their ability to segregate axons and elongate along them, preventing the formation of a 1:1 relationship, which is critical for peripheral nervous system myelination. In contrast, OL branching, differentiation, and myelin formation are potentiated by inhibition of myosin II. Thus, by controlling the spatial and localized activation of actin polymerization, myosin II regulates SC polarization and OL branching, and by extension their ability to form myelin. Our data indicate that the mechanisms regulating myelination in the peripheral and central nervous systems are distinct.

The fine structure and morphological organization of non-myelinated nerve fibres

1956 ◽  
Vol 144 (917) ◽  
pp. 496-506 ◽  
Keyword(s):  
Fine Structure ◽  
Schwann Cell ◽  
Peripheral Nerve ◽  
Schwann Cells ◽  
Myelin Sheath ◽  
Peripheral Nerves ◽  
Nerve Fibres ◽  
Myelinated Nerve ◽  
Morphological Organization ◽  
Myelinated Fibres

The fine structure and morphological organization of non-myelinated nerve fibres were studied by ultra-thin sectioning and electron microscopy in peripheral nerves, autonomic nerves and dorsal roots. Several non-myelinated fibres share the cytoplasm of a Schwann cell. The Schwann cells of non-myelinated fibres form a syncytium. The fibres are incompletely sur­rounded by Schwann cell cytoplasm and are suspended in the cytoplasm by mesaxons formed by the plasma membranes of the Schwann cell. The various relationships of mesaxon and nerve fibre are described. Non-myelinated fibres which do not share a Schwann cell are seen very frequently in the sciatic nerve of a new-born mouse but become less common as myelination proceeds and are rare in adults. It is therefore suggested that in developing peripheral nerves, the non­ myelinated fibres that are destined to myelinate are not organized into groups within a single Schwann cell, even before their myelin sheath has appeared; they are, at least for the ages examined here, individuals in relation to a surrounding individual Schwann cell. It is also suggested that the non-myelinated fibres that will never acquire a myelin sheath are organized in a developing peripheral nerve in the same manner as in the adult nerve—several fibres sharing a single Schwann cell that is part of a syncytial system of Schwann cells. Thus, in a developing peripheral nerve, it appears that two types of non-myelinated fibres are present—one destined to myelinate and lying alone in its own Schwann cell and the other, destined to remain unmyelinated and sharing, along with other non-myelinated fibres of the same type, a Schwann cell. The significance of these observations is discussed in relation to the development of nerve fibres and possible physiological importance.

Sign in / Sign up

Export Citation Format

Share Document