Neurofilament phosphorylation

1995 ◽  
Vol 73 (9-10) ◽  
pp. 575-592 ◽  
Author(s):  
Harish C. Pant ◽  
Veeranna
Keyword(s):  
Molecular Weight ◽  
Nervous System ◽  
Nervous Tissue ◽  
Important Determinant ◽  
Neurofilament Proteins ◽  
Neurofilament Phosphorylation ◽  
Axonal Compartment

Neurofilament proteins (NFPs) are highly phosphorylated molecules in the axonal compartment of the adult nervous system. The phosphorylation of NFP is considered an important determinant of filament caliber, plasticity, and stability. This process reflects the function of NFs during the lifetime of a neuron from differentiation in the embryo through long-term activity in the adult until aging and environmental insult leads to pathology and ultimately death. NF function is modulated by phosphorylation–dephosphorylation in each of these diverse neuronal states. In this review, we have summarized some of these properties of NFP in adult nervous tissue, mostly from work in our own laboratory. Identification of sites phosphorylated in vivo in high molecular weight NFP (NF-H) and properties of NF-associated and neural-specific kinases phosphorylating specific sites in NFP are described. A model to explain the role of NF phosphorylation in determining filament caliber, plasticity, and stability is proposed.Key words: neurofilament proteins, phosphorylation, kinases, phosphatases, regulators, inhibitors, multimesic complex, domains.

THE ROLE OF POLYETHYLENIMINE IN ENHANCING PERFORMANCE OF GLUTAMATE BIOSENSORS

2018 ◽  
Vol 8 (3) ◽  
pp. 36-41
Author(s):  
Diep Do Thi Hong ◽  
Duong Le Phuoc ◽  
Hoai Nguyen Thi ◽  
Serra Pier Andrea ◽  
Rocchitta Gaia
Keyword(s):  
First Generation ◽  
Good Reproducibility ◽  
Complex Matrices ◽  
Long Term Stability ◽  
In Vitro Characterization ◽  
Glutamate Oxidase

Background: The first biosensor was constructed more than fifty years ago. It was composed of the biorecognition element and transducer. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples Glutamate is important biochemicals involved in energetic metabolism and neurotransmission. Therefore, biosensors requires the development a new approach exhibiting high sensibility, good reproducibility and longterm stability. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples. The aims of this work: To find out which concentration of polyethylenimine (PEI) exhibiting the most high sensibility, good reproducibility and long-term stability. Methods: We designed and developed glutamate biosensor using different concentration of PEI ranging from 0% to 5% at Day 1 and Day 8. Results: After Glutamate biosensors in-vitro characterization, several PEI concentrations, ranging from 0.5% to 1% seem to be the best in terms of VMAX, the KM; while PEI content ranging from 0.5% to 1% resulted stable, PEI 1% displayed an excellent stability. Conclusions: In the result, PEI 1% perfomed high sensibility, good stability and blocking interference. Furthermore, we expect to develop and characterize an implantable biosensor capable of detecting glutamate, glucose in vivo. Key words: Glutamate biosensors, PEi (Polyethylenimine) enhances glutamate oxidase, glutamate oxidase biosensors

scholarly journals Short-term and long-term role of platelet activating factor as a mediator of in vivo platelet aggregation.

Circulation ◽  
1993 ◽  
Vol 88 (3) ◽  
pp. 1205-1214 ◽  
Author(s):  
P Golino ◽  
G Ambrosio ◽  
M Ragni ◽  
I Pascucci ◽  
M Triggiani ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activating Factor ◽  
Short Term

Correlation between magnesium and potassium contents in muscle: role of Na(+)-K+ pump

1993 ◽  
Vol 264 (2) ◽  
pp. C457-C463 ◽  
Author(s):  
I. Dorup ◽  
T. Clausen
Keyword(s):  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Deficient Diet ◽  
Young Rats ◽  
Wide Range ◽  
86Rb Influx

In young rats fed a Mg(2+)-deficient diet for 3 wk, Mg2+ and K+ contents in soleus and extensor digitorum longus muscles were significantly reduced and closely correlated. In isolated soleus muscles, Mg2+ depletion induced an even more pronounced loss of K+, and Mg2+ and K+ contents were correlated over a wide range (r = 0.95, P < 0.001). Extracellular Mg2+ (0-1.2 mM) caused no change in total or ouabain-suppressible 86Rb influx. After long-term incubation in Ca(2+)-Mg(2+)-free buffer with EDTA and EGTA, cellular Mg2+ and K+ contents were reduced by 35 and 15%, respectively, without any reduction in ATP and total or ouabain-suppressible 86Rb influx. In Mg(2+)-depleted muscles 42K efflux was increased by up to 42%, and repletion with Mg2+ produced a graded decrease. We conclude that Mg2+ and K+ contents are closely correlated in muscles Mg2+ depleted in vivo or in vitro and that neither extracellular nor moderate intracellular Mg2+ depletion affects total or Na(+)-K+ pump-mediated K+ influx. The reduced K+ content may rather be related to increased K+ efflux from the muscles.

scholarly journals Role of epigenetic effectors in maintenance of the long-term persistent bystander effect in spleen in vivo

2007 ◽  
Vol 28 (8) ◽  
pp. 1831-1838 ◽  
Author(s):  
Igor Koturbash ◽  
Alex Boyko ◽  
Rocio Rodriguez-Juarez ◽  
Robert J. McDonald ◽  
Volodymyr P. Tryndyak ◽  
...  
Keyword(s):  
Bystander Effect

scholarly journals Dynamics of intravital concentration of amino acid metabolites in human brain in post-traumatic period

2019 ◽  
Vol 484 (2) ◽  
pp. 238-242
Author(s):  
N. A. Semenova ◽  
P. E. Menshchikov ◽  
A. V. Manzhurtsev ◽  
M. V. Ublinskiy ◽  
T. A. Akhadov ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Amino Acid ◽  
Human Brain ◽  
Leading Role ◽  
Acid Metabolites ◽  
Post Traumatic ◽  
First Time

Intracellular concentrations of N acetyaspartate (NAA), aspartate (Asp) and glutamate (Glu) were determined for the first time in human brain in vivo, and the effect of severe traumatic brain injury on NAA synthesis in acute and late post-traumatic period was investigated. In MRI‑negative frontal lobes one day after injury Asp and Glu levels were found to decrease by 45 and 35%, respectively, while NAA level decreased by only 16%. A negative correlation between NAA concentration and the ratio of Asp/Glu concentrations was found. In the long-term period, Glu level returned to normal, Asp level remained below normal by 60%, NAA level was reduced by 65% relative to normal, and Asp/Glu ratio significantly decreased. The obtained results revealed leading role of the neuronal aspartate-malate shuttle in violation of NAA synthesis.

scholarly journals Formation of Mallory Body-like Inclusions and Cell Death Induced by Deregulated Expression of Keratin 18

2002 ◽  
Vol 13 (10) ◽  
pp. 3441-3451 ◽  
Author(s):  
Ikuo Nakamichi ◽  
Shigetsugu Hatakeyama ◽  
Keiichi I. Nakayama
Keyword(s):  
Cell Death ◽  
Important Determinant ◽  
Cellular Model ◽  
Microtubule Network ◽  
Cytoplasmic Inclusions ◽  
Mallory Bodies ◽  
Keratin 18 ◽  
Intracellular Aggregates

Mallory bodies (MBs) are cytoplasmic inclusions that contain keratin 8 (K8) and K18 and are present in hepatocytes of individuals with alcoholic liver disease, nonalcoholic steatohepatitis, or benign or malignant hepatocellular neoplasia. Mice fed long term with griseofulvin are an animal model of MB formation. However, the lack of a cellular model has impeded understanding of the molecular mechanism of this process. Culture of HepG2 cells with griseofulvin has now been shown to induce both the formation of intracellular aggregates containing K18 as well as an increase in the abundance of K18 mRNA. Overexpression of K18 in HepG2, HeLa, or COS-7 cells also induced the formation of intracellular aggregates that stained with antibodies to ubiquitin and with rhodamine B (characteristics of MBs formed in vivo), eventually leading to cell death. The MB-like aggregates were deposited around centrosomes and disrupted the microtubular array. Coexpression of K8 with K18 restored the normal fibrous pattern of keratin distribution and reduced the toxicity of K18. In contrast, an NH2-terminal deletion mutant of K8 promoted the formation of intracellular aggregates even in the absence of K18 overexpression. Deregulated expression of K18, or an imbalance between K8 and K18, may thus be an important determinant of MB formation, which compromises the function of centrosomes and the microtubule network and leads to cell death.

scholarly journals Rac signaling in osteoblastic cells is required for normal bone development but is dispensable for hematopoietic development

Blood ◽  
2012 ◽  
Vol 119 (3) ◽  
pp. 736-744 ◽  
Author(s):  
Steven W. Lane ◽  
Serena De Vita ◽  
Kylie A. Alexander ◽  
Ruchan Karaman ◽  
Michael D. Milsom ◽  
...  
Keyword(s):  
Bone Growth ◽  
Bone Development ◽  
Long Bone ◽  
Perivascular Niche ◽  
Hematopoietic Stem ◽  
Hsc Niche ◽  
Rac1 Gtpase

Abstract Hematopoietic stem cells (HSCs) interact with osteoblastic, stromal, and vascular components of the BM hematopoietic microenvironment (HM) that are required for the maintenance of long-term self-renewal in vivo. Osteoblasts have been reported to be a critical cell type making up the HSC niche in vivo. Rac1 GTPase has been implicated in adhesion, spreading, and differentiation of osteoblast cell lines and is critical for HSC engraftment and retention. Recent data suggest a differential role of GTPases in endosteal/osteoblastic versus perivascular niche function. However, whether Rac signaling pathways are also necessary in the cell-extrinsic control of HSC function within the HM has not been examined. In the present study, genetic and inducible models of Rac deletion were used to demonstrate that Rac depletion causes impaired proliferation and induction of apoptosis in the OP9 cell line and in primary BM stromal cells. Deletion of Rac proteins caused reduced trabecular and cortical long bone growth in vivo. Surprisingly, HSC function and maintenance of hematopoiesis in vivo was preserved despite these substantial cell-extrinsic changes. These data have implications for therapeutic strategies to target Rac signaling in HSC mobilization and in the treatment of leukemia and provide clarification to our evolving concepts of HSC-HM interactions.

Towards understanding the neural origins of hibernation

2022 ◽  
Vol 225 (1) ◽  
Author(s):  
Madeleine S. Junkins ◽  
Sviatoslav N. Bagriantsev ◽  
Elena O. Gracheva
Keyword(s):  
Nervous System ◽  
Environmental Conditions ◽  
Calcium Imaging ◽  
Essential Role ◽  
Physiological Responses ◽  
Quiescent State ◽  
Physiological Changes ◽  
In Vivo Calcium Imaging

ABSTRACT Hibernators thrive under harsh environmental conditions instead of initiating canonical behavioral and physiological responses to promote survival. Although the physiological changes that occur during hibernation have been comprehensively researched, the role of the nervous system in this process remains relatively underexplored. In this Review, we adopt the perspective that the nervous system plays an active, essential role in facilitating and supporting hibernation. Accumulating evidence strongly suggests that the hypothalamus enters a quiescent state in which powerful drives to thermoregulate, eat and drink are suppressed. Similarly, cardiovascular and pulmonary reflexes originating in the brainstem are altered to permit the profoundly slow heart and breathing rates observed during torpor. The mechanisms underlying these changes to the hypothalamus and brainstem are not currently known, but several neuromodulatory systems have been implicated in the induction and maintenance of hibernation. The intersection of these findings with modern neuroscience approaches, such as optogenetics and in vivo calcium imaging, has opened several exciting avenues for hibernation research.

Apparatus for long-term ventricular access in the awake canine

1986 ◽  
Vol 61 (1) ◽  
pp. 368-372 ◽  
Author(s):  
E. C. Ellison ◽  
T. T. Pappas ◽  
W. G. Pace ◽  
T. M. O'Dorisio
Keyword(s):  
Molecular Weight ◽  
Central Nervous System ◽  
Cerebrospinal Fluid ◽  
Nervous System ◽  
Peripheral Blood ◽  
Ventricular System ◽  
Blood Levels ◽  
Maximum Frequency ◽  
Fatal Complications

An apparatus is described that permits lateral ventricular cerebrospinal fluid (CSF) to be sampled or an infusion to be performed into the ventricular system in the awake canine. The device has been used in 25 dogs. CSF was sampled, and experiments involving infusions into the lateral ventricle were performed over a 6- to 24-mo period. The maximum frequency of ventricular cannulation using the apparatus was once per week. Complications occurred in 10 dogs, all of which were successfully treated, permitting experiments to continue. Three fatal complications included meningitis in one animal at 24 mo and seizures in two animals, causing death at 12 and 18 mo. Administration of peptides, bombesin, and somatostatin into the ventricular system was followed by prompt rises in bombesin and somatostatin radioimmunoactivity in the CSF. There were no parallel increases of these peptides in the peripheral blood levels up to 2 h after infusion. Peptides of this molecular weight infused with this apparatus do not seem to leak into peripheral blood. The apparatus permits repeated ventricular cannulation in the awake canine for sampling of CSF and administration of biological substances to determine specific central nervous system action.

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