scholarly journals Distinct roles for sphingolipids and glycosphingolipids at different stages of neuronal development.

1998 ◽  
Vol 45 (2) ◽  
pp. 469-478 ◽  
Author(s):  
A H Futerman
Keyword(s):  
Intracellular Transport ◽  
Neuronal Development ◽  
Apoptotic Cell ◽  
Primary Cultures ◽  
Axon Growth ◽  
Axonal Growth ◽  
Neuronal Cultures ◽  
Subsequent Stage ◽  
Transport Pathway ◽  
Sequence Of Events

Studies on the roles of sphingolipids (SLs) and glycosphingolipids (GSLs) at distinct stages of neuronal development have been performed using primary cultures of hippocampal neurons, which are unique among neuronal cultures inasmuch as they develop by a well-characterized and stereotypic sequence of events that gives rise to fully differentiated axons and dendrites. Our data demonstrate that SLs and GSLs play at least three distinct roles in regulating neuronal development, namely: (i) ceramide enhances the formation of minor neuronal processes from lamellipodia and the subsequent stage of axonogenesis; (ii) glucosylceramide synthesis, but not the synthesis of higher-order GSLs, is required for normal axon growth and for accelerated axonal growth upon stimulation by growth factors; and (iii) at both of these stages, ceramide at high concentrations can induce apoptotic cell death. Together, these observations are consistent with the possibility that minor process formation and apoptosis are regulated by ceramide-dependent signaling pathways, whereas axonal growth requires glucosylceramide synthesis, perhaps to support an intracellular transport pathway.

scholarly journals Synchronized synthesis and intracellular transport of serum albumin and apolipoprotein B in cultured rat hepatocytes as studied by double immunofluorescence.

1986 ◽  
Vol 34 (9) ◽  
pp. 1223-1230 ◽  
Author(s):  
G A Keller ◽  
C Glass ◽  
D Louvard ◽  
D Steinberg ◽  
S J Singer
Keyword(s):  
Serum Albumin ◽  
Apolipoprotein B ◽  
Intracellular Transport ◽  
Primary Cultures ◽  
Rat Hepatocytes ◽  
Cell System ◽  
Secretory Proteins ◽  
Transport Pathway ◽  
Apo B ◽  
Normal Rat

Synthesis and intracellular transport of two secretory proteins, serum albumin (SA) and apolipoprotein B (apo B) have been synchronized in primary cultures of normal rat hepatocytes to make possible immunocytochemical study of the transport pathway. Under appropriate conditions of cycloheximide treatment, synthesis of new protein was inhibited and, by double immunofluorescent labeling, the cells were found to be largely depleted of the SA and apo B previously synthesized. Re-initiation of protein synthesis led to sequential appearance of SA and apo B, first in the endoplasmic reticulum, then in the Golgi complex, and finally at the cell surface. These results indicate that it should be feasible to use this cell system for high-resolution investigation of the sequence of structures involved in intracellular transport of SA and apo B by corresponding immunolabeling experiments as observed by electron microscopy.

scholarly journals Prenylation of axonally translated proteins controls NGF-dependent axon growth

2020 ◽  
Author(s):  
Emily Scott-Solomon ◽  
Rejji Kuruvilla
Keyword(s):  
Protein Synthesis ◽  
Neuronal Development ◽  
Axon Growth ◽  
Axonal Growth ◽  
Cellular Functions ◽  
Protein Prenylation ◽  
Local Protein Synthesis ◽  
Extrinsic Cues ◽  
Rac1 Gtpase ◽  
Axonal Protein

SummaryCompartmentalized signaling is critical for cellular organization and specificity of functional outcomes in neurons. Here, we report that post-translational lipidation of newly synthesized proteins in axonal compartments allows for short-term and autonomous responses to extrinsic cues. Using conditional mutant mice, we found that protein prenylation is essential for sympathetic axon innervation of target organs. We identify a localized requirement for prenylation in sympathetic axons to promote axonal growth in response to the neurotrophin, Nerve Growth Factor (NGF). NGF triggers prenylation of proteins including the Rac1 GTPase in axons, counter to the canonical view of prenylation as constitutive, and strikingly, in a manner dependent on axonal protein synthesis. Newly prenylated proteins localize to TrkA-harboring endosomes in axons, and promote receptor trafficking necessary for axonal growth. Thus, coupling of prenylation to local protein synthesis presents a mechanism for spatially segregated cellular functions during neuronal development.

μ-Opiate Receptors in Neuronal Primary Cultures from Cerebral Cortex

1990 ◽  
Vol 17 (3) ◽  
pp. 177-181
Author(s):  
Peter S. Eriksson ◽  
Elisabeth Hansson ◽  
Lars Rönnbäck
Keyword(s):  
Cerebral Cortex ◽  
Primary Cultures ◽  
Opiate Receptors ◽  
Neuronal Cultures ◽  
Camp Accumulation ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Neuronal Primary Cultures ◽  
Dose Dependent ◽  
Μ Receptor

The presence of μ-opioid receptors was demonstrated as effects of receptor stimulation on PGE1-induced cAMP accumulation in neuronal-enriched primary cultures from rat cerebral cortex. Morphine was used as a μ-receptor agonist. There was a dose-dependent inhibition of the PGE1-stimulated cAMP accumulation by morphine, blocked by the μ-receptor antagonist naloxone. These findings suggest that these neuronal cultures express μ-receptors, possibly connected to adenylate cyclase via an inhibitory Gi-protein. The probable use of functional μ-receptors in neurotoxicological tests is discussed.

Trigeminal satellite cells modulate neuronal responses to triptans: relevance for migraine therapy

2011 ◽  
Vol 7 (2-4) ◽  
pp. 109-116 ◽  
Author(s):  
Alice de Corato ◽  
Alessandro Capuano ◽  
Diego Currò ◽  
Giuseppe Tringali ◽  
Pierluigi Navarra ◽  
...  
Keyword(s):  
Neuronal Excitability ◽  
Primary Cultures ◽  
Neuronal Cultures ◽  
Neuronal Responses ◽  
Satellite Glial Cells ◽  
Cgrp Release ◽  
Trigeminal Neurons ◽  
Trigeminal Neuron ◽  
Anti Migraine Drug

In the present paper, we have further developed an in vitro model to study neuronal–glial interaction at trigeminal level by characterizing the effects of conditioned medium (CM) collected from activated primary cultures of satellite glial cells (SGCs) on calcitonin gene-related peptide (CGRP) release from rat trigeminal neurons. Moreover, we investigated whether such release is inhibited by a clinically relevant anti-migraine drug, sumatriptan. CM effects were tested on trigeminal neuronal cultures in different conditions of activation and at different time points. Long-term exposures of trigeminal neurons to CM increased directly neuronal CGRP release, which was further enhanced by the exposure to capsaicin. In this framework, the anti-migraine drug sumatriptan was able to inhibit the evoked CGRP release from naïve trigeminal neuron cultures, as well as from trigeminal cultures pre-exposed for 30 min to CM. On the contrary, sumatriptan failed to inhibit evoked CGRP release from trigeminal neurons after prolonged (4 and 8 h) pre-exposures to CM. These findings were confirmed in co-culture experiments (neurons and SGCs), where activation of SGCs or a bradykinin priming were used. Our data demonstrate that SGCs activation could influence neuronal excitability, and that this event affects the neuronal responses to triptans.

scholarly journals Bystander Attenuation of Neuronal and Astrocyte Intercellular Communication by Murine Cytomegalovirus Infection of Glia

2007 ◽  
Vol 81 (13) ◽  
pp. 7286-7292 ◽  
Author(s):  
Winson S. C. Ho ◽  
Anthony N. van den Pol
Keyword(s):  
Intercellular Communication ◽  
Neuronal Development ◽  
Primary Cultures ◽  
Synaptic Activity ◽  
Murine Cytomegalovirus ◽  
Intercellular Signaling ◽  
Mcmv Infection ◽  
High Potassium ◽  
Infected Cells ◽  
The Brain

ABSTRACT Astrocytes are the first cells infected by murine cytomegalovirus (MCMV) in primary cultures of brain. These cells play key roles in intercellular signaling and neuronal development, and they modulate synaptic activity within the nervous system. Using ratiometric fura-2 digital calcium imaging of >8,000 neurons and glia, we found that MCMV-infected astrocytes showed an increase in intracellular basal calcium levels and an enhanced response to neuroactive substances, including glutamate and ATP, and to high potassium levels. Cultured neurons with no sign of MCMV infection showed attenuated synaptic signaling after infection of the underlying astrocyte substrate, and intercellular communication between astrocytes with no sign of infection was reduced by the presence of infected glia. These bystander effects would tend to cause further deterioration of cellular communication in the brain in addition to the problems caused by the loss of directly infected cells.

scholarly journals Medicinal Leech CNS as a Model for Exosome Studies in the Crosstalk between Microglia and Neurons

2018 ◽  
Vol 19 (12) ◽  
pp. 4124 ◽  
Author(s):  
Antonella Raffo-Romero ◽  
Tanina Arab ◽  
Issa Al-Amri ◽  
Francoise Le Marrec-Croq ◽  
Christelle Van Camp ◽  
...  
Keyword(s):  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Ex Vivo ◽  
Present Report ◽  
Primary Cultures ◽  
Cell Communication ◽  
Medicinal Leech ◽  
Neuronal Cultures ◽  
Primary Neuronal Cultures ◽  
A Cell

In healthy or pathological brains, the neuroinflammatory state is supported by a strong communication involving microglia and neurons. Recent studies indicate that extracellular vesicles (EVs), including exosomes and microvesicles, play a key role in the physiological interactions between cells allowing central nervous system (CNS) development and/or integrity. The present report used medicinal leech CNS to investigate microglia/neuron crosstalk from ex vivo approaches as well as primary cultures. The results demonstrated a large production of exosomes from microglia. Their incubation to primary neuronal cultures showed a strong interaction with neurites. In addition, neurite outgrowth assays demonstrated microglia exosomes to exhibit significant neurotrophic activities using at least a Transforming Growth Factor beta (TGF-β) family member, called nGDF (nervous Growth/Differentiation Factor). Of interest, the results also showed an EV-mediated dialog between leech microglia and rat cells highlighting this communication to be more a matter of molecules than of species. Taken together, the present report brings a new insight into the microglia/neuron crosstalk in CNS and would help deciphering the molecular evolution of such a cell communication in brain.

scholarly journals MicroExonator enables systematic discovery and quantification of microexons across mouse embryonic development

2020 ◽  
Author(s):  
Guillermo E. Parada ◽  
Roberto Munita ◽  
Ilias Georgakopoulos-Soares ◽  
Hugo Fernandez ◽  
Emmanouil Metzakopian ◽  
...  
Keyword(s):  
Neuronal Development ◽  
Synapse Formation ◽  
De Novo ◽  
Axon Growth ◽  
Developmental Time ◽  
Rna Seq ◽  
Mouse Tissues ◽  
Comprehensive Survey ◽  
Mouse Transcript ◽  
Mouse Visual Cortex

AbstractMicroexons, exons that are ≤30 nucleotides, were shown to play key roles in neuronal development, but are difficult to detect and quantify using standard RNA-Seq alignment tools. Here, we present MicroExonator, a novel pipeline for reproducible de novo discovery and quantification of microexons. We processed 289 RNA-seq datasets from eighteen mouse tissues corresponding to nine embryonic and postnatal stages, providing the most comprehensive survey of microexons available for mouse. We detected 2,984 microexons, 332 of which are differentially spliced throughout mouse embryonic brain development, including 29 that are not present in mouse transcript annotation databases. Unsupervised clustering of microexons alone segregates brain tissues by developmental time and further analysis suggest a key function for microexon inclusion in axon growth and synapse formation. Finally, we analysed single-cell RNA-seq data from the mouse visual cortex and we report differential inclusion between neuronal subpopulations, suggesting that some microexons could be cell-type specific.

scholarly journals Frizzled3 controls axonal development in distinct populations of cranial and spinal motor neurons

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Zhong L Hua ◽  
Philip M Smallwood ◽  
Jeremy Nathans
Keyword(s):  
Cell Death ◽  
Motor Neurons ◽  
Planar Cell Polarity ◽  
Motor Nerve ◽  
Normal Wave ◽  
Axon Growth ◽  
Axonal Growth ◽  
Cell Complexes ◽  
Developing Neurons

Disruption of the Frizzled3 (Fz3) gene leads to defects in axonal growth in the VIIth and XIIth cranial motor nerves, the phrenic nerve, and the dorsal motor nerve in fore- and hindlimbs. In Fz3−/− limbs, dorsal axons stall at a precise location in the nerve plexus, and, in contrast to the phenotypes of several other axon path-finding mutants, Fz3−/− dorsal axons do not reroute to other trajectories. Affected motor neurons undergo cell death 2 days prior to the normal wave of developmental cell death that coincides with innervation of muscle targets, providing in vivo evidence for the idea that developing neurons with long-range axons are programmed to die unless their axons arrive at intermediate targets on schedule. These experiments implicate planar cell polarity (PCP) signaling in motor axon growth and they highlight the question of how PCP proteins, which form cell–cell complexes in epithelia, function in the dynamic context of axonal growth.

scholarly journals Glycogen serves as an energy source that maintains astrocyte cell proliferation in the neonatal telencephalon

2016 ◽  
Vol 37 (6) ◽  
pp. 2294-2307 ◽  
Author(s):  
Hitoshi Gotoh ◽  
Tadashi Nomura ◽  
Katsuhiko Ono
Keyword(s):  
Energy Source ◽  
Cell Proliferation ◽  
Glycogen Phosphorylase ◽  
Cell Cycle Progression ◽  
Neuronal Development ◽  
Kinase Inhibitors ◽  
Primary Cultures ◽  
Glycogen Metabolism ◽  
Radial Glial Cells

Large amounts of energy are required when cells undergo cell proliferation and differentiation for mammalian neuronal development. Early neonatal mice face transient starvation and use stored energy for survival or to support development. Glycogen is a branched polysaccharide that is formed by glucose, and serves as an astrocytic energy store for rapid energy requirements. Although it is present in radial glial cells and astrocytes, the role of glycogen during development remains unclear. In the present study, we demonstrated that glycogen accumulated in glutamate aspartate transporter (GLAST)+ astrocytes in the subventricular zone and rostral migratory stream. Glycogen levels markedly decreased after birth due to the increase of glycogen phosphorylase, an essential enzyme for glycogen metabolism. In primary cultures and in vivo, the inhibition of glycogen phosphorylase decreased the proliferation of astrocytic cells. The number of cells in the G1 phase increased in combination with the up-regulation of cyclin-dependent kinase inhibitors or down-regulation of the phosphorylation of retinoblastoma protein (pRB), a determinant for cell cycle progression. These results suggest that glycogen accumulates in astrocytes located in specific areas during the prenatal stage and is used as an energy source to maintain normal development in the early postnatal stage.

Poly(ADP-ribose) polymerase-1-deficient mice are protected from angiotensin II-induced cardiac hypertrophy

2006 ◽  
Vol 291 (4) ◽  
pp. H1545-H1553 ◽  
Author(s):  
Jyothish B. Pillai ◽  
Madhu Gupta ◽  
Senthilkumar B. Rajamohan ◽  
Roberto Lang ◽  
Jai Raman ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Cell Signaling ◽  
Primary Cultures ◽  
Heart Weight ◽  
Cell Protein ◽  
Sequence Of Events ◽  
Deficient Mice

Poly(ADP-ribose) polymerase-1 (PARP), a chromatin-bound enzyme, is activated by cell oxidative stress. Because oxidative stress is also considered a main component of angiotensin II-mediated cell signaling, it was postulated that PARP could be a downstream target of angiotensin II-induced signaling leading to cardiac hypertrophy. To determine a role of PARP in angiotensin II-induced hypertrophy, we infused angiotensin II into wild-type (PARP+/+) and PARP-deficient mice. Angiotensin II infusion significantly increased heart weight-to-tibia length ratio, myocyte cross-sectional area, and interstitial fibrosis in PARP+/+ but not in PARP−/− mice. To confirm these results, we analyzed the effect of angiotensin II in primary cultures of cardiomyocytes. When compared with PARP−/− cardiomyocytes, angiotensin II (1 μM) treatment significantly increased protein synthesis in PARP+/+ myocytes, as measured by 3H-leucine incorporation into total cell protein. Angiotensin II-mediated hypertrophy of myocytes was accompanied with increased poly-ADP-ribosylation of nuclear proteins and depletion of cellular NAD content. When cells were treated with cell death-inducing doses of angiotensin II (10–20 μM), robust myocyte cell death was observed in PARP+/+ but not in PARP−/− myocytes. This type of cell death was blocked by repletion of cellular NAD levels as well as by activation of the longevity factor Sir2α deacetylase, indicating that PARP induction and subsequent depletion of NAD levels are the sequence of events causing angiotensin II-mediated cardiomyocyte cell death. In conclusion, these results demonstrate that PARP is a nuclear integrator of angiotensin II-mediated cell signaling contributing to cardiac hypertrophy and suggest that this could be a novel therapeutic target for the management of heart failure.

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