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1

The association of activated receptor Fc gamma II with plasma membrane rafts, revealed by confocal and immunoelectron microscopy

100%
Strzelecka-Kiliszek A., Kwiatkowska K., Shakor A. B. A., Sobota A.
Cellular and Molecular Biology Letters
|
2002
|
tom 07
|
nr Suppl.
2

Sphingolipid derivatives modulate intracellular Ca2plus in rat synaptosomes

86%
Miguel B. G., Calcerrada M. C., Catalan R. E., Martinez A. M.
Acta Neurobiologiae Experimentalis
|
2001
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tom 61
|
nr 2
3

Human fibroblasts in culture metabolize differently exogenous GM3 ganglioside species containing C18 and C20 sphingosine

86%
Chigorno V., Valsecchi M., Sonnino S.
Acta Biochimica Polonica
|
1998
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tom 45
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nr 2
Preparation of radioactive GM3 species containing isotopically labeled C18 sphingosine or C20 sphingosine is reported and their use for studying some aspects of the sphingolipid biosynthesis in cells is discussed. Human fibroblasts in culture that have only C18 sphingolipids and GM3 as the major gangliosides, were fed with the two radioactive GM3 species. The radioactive gangliosides were taken up by the cells and metabolized. The analyses of the radioactivity metabolic fate, in this model provides the following information. i - About 70-80% of the total catabolic sphingosine is re-cycled for biosynthesis of complex sphingolipids. ii - A small amount of the catabolic C20 sphingosine was re-cycled for biosynthesis of C20 sphingolipids, thus yielding complex lipids that are not naturally present in fibroblast cells. iii - A regulatory step in the biosynthesis of sphingolipid species differring long chain base content, C18 or C20 sphingosine, is in some way involved in the first steps of sphingolipid biosynthesis, and thus plays a decisive role in the availability of the long chain bases.
4
Content available remote

Effect of atrial pacing on the level of bioactive sphingolipids in the heart ventricles of the rat

72%
Wojcik B., Baranowski M., Chabowski A., Gorski J.
Journal of Physiology and Pharmacology
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2015
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tom 66
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nr 3
5

Alteration of sphingolipid biostat in experimental model of oxidative stress evoked by 1-methyl-4-phenylpyridinium (MPPplus)

72%
Pyszko J., Strosznajder J. B.
Acta Neurobiologiae Experimentalis
|
2013
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tom 73
|
nr 1
Bioactive sphingolipids are important molecules that control wide spectrum of neuronal processes including neurotransmission, synaptic function, cells proliferation and death. Sphingosine kinases (SK1/2) are conserved enzymes that phosphorylate sphingosine to sphingosine-1-phosphate (S1P), which acts as a primary and secondary messenger. S1P binds to 5 receptors and plays essential role in neural signal transduction under physiological and various pathological conditions. Although growing evidence suggests important role of SK1/2 and S1P in neurodegenerative disorders including ischemia, inflammation and Alzheimer’s Disease, till now disturbances of sphingolipids homeostasis in Parkinson’s Disease (PD) remain unknown. Our study try to explain the role of SK1/2 and S1P in molecular mechanism of cell survival and death in model of oxidative stress evoked by neurotoxin 1-methyl-4-phenylpyridinium (MPP+), compound widely used in experimental model of PD. Our data presented that MPP+, comparable to SK inhibition evoked death of human neuroblastoma cells SH-SY5Y in time and concentration dependent manner. These changes are accompanied by increased free radicals concentration in these cells. Reduced level of SK1 protein was detected in SH-SY5Y cells after 24h exposure to MPP+ comparing to control. Moreover S1P pretreatment enhanced survival of these cells and protein level of SK1 comparing to MPP+ treated cells. Our data indicated that MPP+ evoked neuronal death is mediated by SK1/2 inhibition and altered sphingolipids signaling. These molecular events lead to caspase dependent apoptotic cells death and poly(ADP-ribose) polymerase-1 (PARP-1) degradation. All above results presented the alteration of sphingolipid biostat in experimental model of PD and suggested that S1P can offer novel, protective strategy.Supported by NCN Grant 5870/B/PO1/2011/40
6

Sphingosine-1-phosphate: a master regulator of lymphocyte egress and immunity

72%
Simmons S., Ishii M.
Archivum Immunologiae et Therapiae Experimentalis
|
2014
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tom 62
|
nr 2
7

Mobilization of intracellular calcium by intracellular flash photolysis of caged dihydrosphingosine in cultured neonatal rat sensory neurones

72%
Ayar A., Thatcher N. M., Zehavi U., Trentham D. R., Scott R. H.
Acta Biochimica Polonica
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1998
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tom 45
|
nr 2
The ability of dihydrosphingosine to release Ca2+ from intracellular stores in neurones was investigated by combining the whole cell patch clamp technique with intracellular flash photolysis of caged, N-(2-nitrobenzyl)dihydrosphingosine. The caged dihydrosphingosine (100 μM) was applied to the intracellular environment via the CsCl-based patch pipette solution which also contained 0.3% dimethylformamide and 2 μM dithiothreitol. Cultured dorsal root ganglion neurones from neonatal rats were voltage clamped at -90 mV and inward whole cell Ca2+-activated currents were recorded in response to intracellular photorelease of dihydrosphingosine. Intracellular photorelease of dihydrosphingosine (about 5 μM) was achieved using a Xenon flash lamp. Inward Ca2+-activated currents were evoked in 50 out of 57 neurones, the mean delay to current activation following photolysis was 82±13 s. The responses were variable with neurones showing transient, oscillating or sustained inward currents. High voltage-activated Ca2+ currents evoked by 100 ms voltage step commands to 0 mV were not attenuated by photorelease of dihydrosphingosine. Controls showed that alone a flash from the Xenon lamp did not activate currents, and that the unphotolysed caged dihydrosphingosine, and intracellular photolysis of 2-(2-nitrobenzylamino) propanediol also did not evoke responses. The dihydrosphingosine current had a reversal potential of -11±3 mV (n = 11), and was carried by two distinct Cl- and cation currents which were reduced by 85% and about 20% following replacement of monovalent cations with N-methyl-D-glucamine or application of the Cl- channel blocker niflumic acid (10 μM) respectively. The responses to photoreleased dihydrosphingosine were inhibited by intracellular application of 20 μM EGTA, 10 μM ryanodine or extracellular application of 10 μM dantrolene, but persisted when Ca2+ free saline was applied to the extracellular environment. Intracellular application of uncaged dihydrosphingosine evoked responses which were attenuated by photolysis of the caged Ca2+ chelator Diazo-2. Experiments also suggested that extracellular application of dihydrosphingosine can activate membrane conductances. We conclude that dihydrosphingosine directly or indirectly mobilises Ca2+ from ryanodine-sensitive intracellular stores in cultured sensory neurones.
8

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

72%
Futerman A. H.
Acta Biochimica Polonica
|
1998
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tom 45
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nr 2
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.
9

The role of the lysophospholipid sphingosine 1-phosphate in immune cell biology

72%
Von Wenckstern H., Zimmermann K., Kleuser B.
Archivum Immunologiae et Therapiae Experimentalis
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2006
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tom 54
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nr 4
10

Beyond a structural component: sphingolipids in immunology

72%
Prieschl E. E., Baumruker T.
Archivum Immunologiae et Therapiae Experimentalis
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2000
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tom 48
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nr 3
11
Content available remote

Cardioprotective role of sphingosine-1-phosphate

58%
Knapp M.
Journal of Physiology and Pharmacology
|
2011
|
tom 62
|
nr 6
12

The role of sphingosine kinases/sphingosine-1-phosphate in the regulation of alpha-synuclein and amyloid beta precursor protein secretion. Implications for neurodegenerative disorders

58%
Jesko H., Okada T., Nakamura S., Strosznajder R. P.
Acta Neurobiologiae Experimentalis
|
2013
|
tom 73
|
nr 1
Sphingolipid deregulation may be an important factor of age-related neuronal stress vulnerability. Current data suggests potential links between sphingosine kinases (SphK1&2), their product sphingosine1-phosphate (S1P) and age-related protein conformation diseases. The aim of this study was to investigate a possible role of SphKs in alpha-synuclein (ASN) and amyloid beta (ABeta) precursor protein (APP) level and secretion. The studies were carried out using human SH-SY5Y neuroblastoma cell line stably transfected with the human gene for α-synuclein (ASNwt). Sphingosine kinase inhibitor (SKI) significantly increased ASN secretion in concentration-dependent manner. S1P also displayed similar influence. Neither compound exerted any significant effect on the ASN protein level. S1P may act via cell surface receptors or as an intracellular second messenger. The similar effect of S1P and SphK inhibitors on ASN secretion may suggest that the regulation of its release is critically dependent on the varied (intra)cellular targets of SphKs and downstream signaling pathways. We have found that stable human ASNwt expression in SH-SY5Y cells caused a three-fold, significant increase of the cellular APP level. In ASN-transfected cells S1P enhanced APP secretion and reduced its intracellular level. This could be linked to the recently reported effect of S1P on secretase beta activity. Inhibition of SphKs significantly decreased APP secretion. In summary our data indicates that endogenous ASN regulates APP level in SH-SY5Y cells and that sphingolipids play a crucial role in the secretion of ASN and APP. These processes may have significant impact on neuronal survival and health.
13
Content available remote

The role of oligodendrocytes in chronic pain: cellular and molecular mechanisms

58%
Malta I., Moraes T., Rodrigues G., Franco P., Galdino G.
Journal of Physiology and Pharmacology
|
2019
|
tom 70
|
nr 5
14

On the character and functions of sphingolipids

58%
Karlsson K. A.
Acta Biochimica Polonica
|
1998
|
tom 45
|
nr 2
Sphingolipids form a large group of membrane lipids showing a diversity of molecular species. Specific functions associated with the saccharide part of glycosphingolipids including co-receptor functions, cell homing phenomena, and attachment by microbes and microbial toxins may not be unique for sphingolipids. However, there are saccharides which appear only in ceramide-bound form and not in other glycoconjugates, and such glycolipids have often been selected as attachment sites by microbes. During the last few years convincing evidence has been presented in favor of ceramide and sphingosine being signaling molecules for various cell functions. The influence of sphingolipids (ceramide) on the properties of the membrane bilayer is still largely unknown. However, based on the structure of ceramide and some experimental evidence one may formulate its role in membrane stability and barrier properties determined by hydrogen bonding in the amide region of ceramide. Furthermore, a natural variation in the number of hydroxyl groups (of fatty acid and long-chain base) may be important for regulation of the potential hydrogen bonds.
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