scholarly journals Adhesion among neural cells of the chick embryo. IV. Role of the cell surface molecule CAM in the formation of neurite bundles in cultures of spinal ganglia.

1978 ◽  
Vol 79 (2) ◽  
pp. 382-393 ◽  
Author(s):  
U Rutishauser ◽  
W E Gall ◽  
G M Edelman
Keyword(s):  
Cell Adhesion Molecule ◽  
Plasma Membranes ◽  
Spinal Ganglion ◽  
Spinal Ganglia ◽  
Neural Cells ◽  
Entire Surface ◽  
Cell Surface Molecule ◽  
Neurite Elongation ◽  
Neural Tissues

The cell adhesion molecule (CAM) is involved in adhesion among embryonic retinal and brain cells and has been detected in a variety of neural tissues. This paper describes the use of spinal ganglion cultures and specific anti-CAM antibodies to determine the distribution of CAM on plasma membranes of nerve processes, and to assess the results of perturbation of its function during the growth of neurites from ganglia. The results indicate that CAM is distributed over the entire surface of nerve processes, and that specific anti-CAM Fab' fragments alter the morphology of neurite outgrowth. In particular, it was observed that anti-CAM inhibits formation of nerve bundles, so that the ganglion becomes surrounded by a tangled net of fine processes. Growth cone functions, such as neurite elongation, motility, and attachment to the substratum, did not appear to be affected by the antibody. These studies suggest that one of the major functions of CAM is to mediate side-to-side adhesion between neurites to form fascicles, and raise the possibility that this molecule serves a key role in embryogenesis of nerve tissues.

Spreading of a sperm surface antigen within the plasma membrane of the egg after fertilization in the rat

Development ◽  
1983 ◽  
Vol 75 (1) ◽  
pp. 259-270
Author(s):  
Stephen J. Gaunt
Keyword(s):  
Monoclonal Antibody ◽  
Plasma Membrane ◽  
Guinea Pig ◽  
Surface Antigen ◽  
Plasma Membranes ◽  
Entire Surface ◽  
Sperm Tail ◽  
Sperm Surface ◽  
Sperm Antigens

The rat sperm surface antigen 2D6, located over the entire surface of the spermatozoon, is shown by use of a monoclonal antibody in indirect immunofluorescence experiments to spread laterally over the surface of the egg after fusion of sperm and egg plasma membranes at fertilization. Freshly fertilized eggs, obtained from superovulated rats 14h after hCG injection, showed the 2D6 antigen to have spread in a gradient over a discrete fan-shaped area of the egg surface anterior to the protruding sperm tail. Eggs at a later stage of sperm incorporation, obtained 20 h after hCG injection, snowed that the spread of antigen had extended to cover most or all of their surfaces. By 40 h after hCG injection, the approximate time that fertilized eggs cleaved to form 2-cell embryos, most of the 2D6 antigen had been lost from the cell surface. Fertilized eggs, but not unfertilized eggs or 2-cell embryos, were lysed by 2D6 monoclonal antibody in the presence of guinea pig complement. A model for sperm-egg fusion is presented to account for the observed pattern of spreading shown by the 2D6 antigen. The possible role of sperm antigens on the egg surface is discussed.

Congenital Sacrococcygeal Teratomas: Effect of Gestational Age on Size, Morphologic Pattern, Ploidy, p53, and ret Expression

2000 ◽  
Vol 3 (3) ◽  
pp. 240-248 ◽  
Author(s):  
Marille E. Herrmann ◽  
Karen Thompson ◽  
Eva M. Wojcik ◽  
Robert Martinez ◽  
Aliya N. Husain
Keyword(s):  
Gestational Age ◽  
Cell Cycle Control ◽  
Relative Size ◽  
Tyrosine Kinase Receptor ◽  
Neural Cells ◽  
Aneuploid Cell ◽  
Morphological Pattern ◽  
Neural Tissues ◽  
Receptor Family

Prognosis of infants born with sacrococcygeal teratomas (SCTs) correlates with gestational age (GA). The survival rate after 30 weeks of gestation is 75%, compared to 7% before 30 weeks of gestation. Studies correlating GA with size, morphologic composition of teratomas, ploidy or expression of cell cycle control proteins such as p53, and ret [a tyrosine kinase receptor of the GDNF (glial cell line–derived neurotrophic factors)] receptor family may provide information explaining differences in survival. Seven SCTs (GA 21 to 41 weeks), ranging in size from 5 to 15 cm, were evaluated for morphologic composition. DNA ploidy was assessed in mature and immature neural elements. Immunohistochemical reactivity with monoclonal antibodies recognizing p53, and ret was quantitated and correlated with morphological pattern and GA. Relative size of teratomas to infants' weight and content of immature neural tissues correlated inversely with advancement of GA. Yolk sac tumor (YST) and immature tissues showed aneuploid cell populations. Nuclear p53 reactivity was apparent in the teratoma with YST in the microcystic patterns, the neuroectodermal rosettes, and the glandular patterns. Ret reactivity was seen in osteoclasts adjacent to bone formation surrounding developing teeth in an immature teratoma, and in rare mature neural cells of one SCT of 35 weeks GA. The rapid growth of SCT (GA <30 weeks) correlates with increase in immature neural tissues. Our study confirms aneuploidy in YST and suggests aneuploid populations within immature tissues. p53 accumulates in a variety of patterns of YST and may be seen in immature components of SCTs. To understand the possible role of ret, further studies comparing ret expression in immature human tissues are needed.

scholarly journals Regulation of the Brain Neural Niche by Soluble Molecule Akhirin

2021 ◽  
Vol 9 (3) ◽  
pp. 29
Author(s):  
Mikiko Kudo ◽  
Kunimasa Ohta
Keyword(s):  
Spinal Cord ◽  
Blood Vessels ◽  
Molecular Mechanisms ◽  
Neural Progenitor Cells ◽  
Central Canal ◽  
Neural Cells ◽  
Neural Tissues ◽  
The Central Nervous System ◽  
The Brain

In the central nervous system (CNS), which comprises the eyes, spinal cord, and brain, neural cells are produced by the repeated division of neural stem cells (NSCs) during the development of the CNS. Contrary to the notion that the CNS is relatively static with a limited cell turnover, cells with stem cell-like properties have been isolated from most neural tissues. The microenvironment, also known as the NSC niche, consists of NSCs/neural progenitor cells, other neurons, glial cells, and blood vessels; this niche is thought to regulate neurogenesis and the differentiation of NSCs into neurons and glia. Although it has been established that neurons, glia, and blood vessels interact with each other in a complex manner to generate neural tissues in the NSC niche, the underlying molecular mechanisms in the CNS niche are unclear. Herein, we would like to introduce the extracellular secreted protein, Akhirin (AKH; Akhi is the Bengali translation for eye). AKH is specifically expressed in the CNS niche—the ciliary body epithelium in the retina, the central canal of the spinal cord, the subventricular zone, and the subgranular zone of the dentate gyrus of the hippocampus—and is supposedly involved in NSC niche regulation. In this review, we discuss the role of AKH as a niche molecule during mouse brain formation.

scholarly journals Myosin XVI in the Nervous System

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1903
Author(s):  
Elek Telek ◽  
András Kengyel ◽  
Beáta Bugyi
Keyword(s):  
Nervous System ◽  
Neurological Disorders ◽  
Current Knowledge ◽  
Structural Features ◽  
Neural Cells ◽  
Cellular Functions ◽  
Cytoskeleton Reorganization ◽  
Neural Tissues ◽  
Cell Signaling Pathways

The myosin family is a large inventory of actin-associated motor proteins that participate in a diverse array of cellular functions. Several myosin classes are expressed in neural cells and play important roles in neural functioning. A recently discovered member of the myosin superfamily, the vertebrate-specific myosin XVI (Myo16) class is expressed predominantly in neural tissues and appears to be involved in the development and proper functioning of the nervous system. Accordingly, the alterations of MYO16 has been linked to neurological disorders. Although the role of Myo16 as a generic actin-associated motor is still enigmatic, the N-, and C-terminal extensions that flank the motor domain seem to confer unique structural features and versatile interactions to the protein. Recent biochemical and physiological examinations portray Myo16 as a signal transduction element that integrates cell signaling pathways to actin cytoskeleton reorganization. This review discusses the current knowledge of the structure-function relation of Myo16. In light of its prevalent localization, the emphasis is laid on the neural aspects.

Pathogenic and Compensatory Mechanisms in Epidermis of Sphingomyelin Synthase 2-Deficient Mice

2021 ◽  
pp. 1-7
Author(s):  
Shota Sakai ◽  
Asami Makino ◽  
Akihito Nishi ◽  
Takeshi Ichikawa ◽  
Tadashi Yamashita ◽  
...  
Keyword(s):  
Plasma Membranes ◽  
Lamellar Body ◽  
Lipid Mediator ◽  
Permeability Barrier ◽  
Compensatory Mechanisms ◽  
Terrestrial Environment ◽  
Sphingomyelin Synthase ◽  
Epidermal Permeability Barrier ◽  
Deficient Mice

Sphingomyelin (SM) is a constituent of cellular membranes, while ceramides (Cer) produced from SM on plasma membranes serve as a lipid mediator that regulates cell proliferation, differentiation, and apoptosis. In the skin, SM also is a precursor of Cer, an important constituent of epidermal permeability barrier. We investigated the role of epidermal SM synthase (SMS)2, an isoform of SMS, which modulates SM and Cer levels on plasma membranes. Although SMS2-knockout (SMS2-KO) mice were not neonatal lethal, an ichthyotic phenotype with epidermal hyperplasia and hyperkeratosis was evident at birth, which persisted until 2 weeks of age. These mice showed abnormal lamellar body morphology and secretion, and abnormal extracellular lamellar membranes in the stratum corneum. These abnormalities were no longer evident by 4 weeks of age in SMS2-KO mice. Our study suggests that (1) exposure to a dry terrestrial environment initiates compensatory responses, thereby normalizing epidermal ichthyotic abnormalities and (2) that a nonlethal gene abnormality can cause an ichthyotic skin phenotype.

The biological activity of glucagon–phospholipid complexes

1983 ◽  
Vol 61 (7) ◽  
pp. 688-691 ◽  
Author(s):  
J. J. Liepnieks ◽  
P. Stoskopf ◽  
E. A. Carrey ◽  
C. Prosser ◽  
R. M. Epand
Keyword(s):  
Biological Activity ◽  
Adenylate Cyclase ◽  
Plasma Membranes ◽  
Bovine Brain ◽  
Water Soluble ◽  
Dipalmitoyl Phosphatidylcholine ◽  
Dimyristoyl Phosphatidylcholine ◽  
Lipoprotein Complex ◽  
Stimulation Of

Glucagon can form water-soluble complexes with phospholipids. The incorporation of glucagon into these lipoprotein particles reduces the biological activity of the hormone. The effect is observed only at temperatures below the phase transition temperature of the phospholipid and results in a decreased stimulation of the adenylate cyclase of rat liver plasma membranes by the lipoprotein complex as compared with the hormone in free solution. Two- to five-fold higher concentrations of glucagon are required for half-maximal stimulation of adenylate cyclase when the hormone is complexed with dimyristoyl phosphatidylcholine, dipalmitoyl phosphatidylcholine, or bovine brain sphingomyelin. A possible role of lipoprotein-associated hormones in the development of insulin resistance is discussed.

scholarly journals The Protective Role of Brain CYP2J in Parkinson’s Disease Models

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yueran Li ◽  
Jinhua Wu ◽  
Xuming Yu ◽  
Shufang Na ◽  
Ke Li ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Brain Regions ◽  
Protective Role ◽  
Neural Cells ◽  
Endogenous Substrates ◽  
6 Hydroxydopamine ◽  
Myd88 Signaling ◽  
Lps Treatment

CYP2J proteins are present in the neural cells of human and rodent brain regions. The aim of this study was to investigate the role of brain CYP2J in Parkinson’s disease. Rats received right unilateral injection with lipopolysaccharide (LPS) or 6-hydroxydopamine (6-OHDA) in the substantia nigra following transfection with or without the CYP2J3 expression vector. Compared with LPS-treated rats, CYP2J3 transfection significantly decreased apomorphine-induced rotation by 57.3% at day 12 and 47.0% at day 21 after LPS treatment; moreover, CYP2J3 transfection attenuated the accumulation of α-synuclein. Compared with the 6-OHDA group, the number of rotations by rats transfected with CYP2J3 decreased by 59.6% at day 12 and 43.5% at day 21 after 6-OHDA treatment. The loss of dopaminergic neurons and the inhibition of the antioxidative system induced by LPS or 6-OHDA were attenuated following CYP2J3 transfection. The TLR4-MyD88 signaling pathway was involved in the downregulation of brain CYP2J induced by LPS, and CYP2J transfection upregulated the expression of Nrf2 via the inhibition of miR-340 in U251 cells. The data suggest that increased levels of CYP2J in the brain can delay the pathological progression of PD initiated by inflammation or neurotoxins. The alteration of the metabolism of the endogenous substrates (e.g., AA) could affect the risk of neurodegenerative disease.

Role of plasma membranes in stimulation of RNA-directed DNA synthesis

Nature ◽  
1976 ◽  
Vol 262 (5571) ◽  
pp. 805-807 ◽  
Author(s):  
L. C. PADHY ◽  
S. K. KAR ◽  
K. K. RAO ◽  
M. R. DAS
Keyword(s):  
Dna Synthesis ◽  
Plasma Membranes ◽  
Stimulation Of
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