scholarly journals Characterization of the De Novo Biosynthetic Enzyme of Platelet Activating Factor, DDT-Insensitive Cholinephosphotransferase, of Human Mesangial Cells

2007 ◽  
Vol 2007 ◽  
pp. 1-10 ◽  
Author(s):  
Alexandros Basilios Tsoupras ◽  
Elizabeth Fragopoulou ◽  
Tzortzis Nomikos ◽  
Christos Iatrou ◽  
Smaragdi Antonopoulou ◽  
...  
Keyword(s):  
De Novo ◽  
Mesangial Cells ◽  
Sparus Aurata ◽  
Platelet Activating Factor ◽  
Sea Bream ◽  
Inflammatory Factors ◽  
Renal Diseases ◽  
In Vitro Tests

Platelet activating factor (PAF), a potent inflammatory mediator, is implicated in several proinflammatory/inflammatory diseases such as glomerulonephritis, glomerulosclerosis, atherosclerosis, cancer, allergy, and diabetes. PAF can be produced by several renal cells under appropriate stimuli and it is thought to be implicated in renal diseases. The aim of this study is the characterization of DTT-insensitive cholinephosphotransferase (PAF-CPT) of human mesangial cell (HMC), the main regulatory enzyme of PAFde novobiosynthetic pathway. Microsomal fractions of mesangial cells were isolated and enzymatic activity and kinetic parameters were determined by TLC and in vitro biological test in rabbit washed platelets. The effect of bovine serum albumin (BSA), dithiothreitol (DTT), divalent cations (Mg2+and Ca2+), EDTA, and various chemicals on the activity of PAF-CPT of HMC was also studied. Moreover, preliminary in vitro tests have been performed with several anti-inflammatory factors such as drugs (simvastatin, IFNa, rupatadine, tinzaparin, and salicylic acid) and bioactive compounds of Mediterranean diet (resveratrol and lipids of olive oil, olive pomace, sea bass “Dicentrarchuslabrax,” and gilthead sea bream “Sparus aurata”). The results indicated that the above compounds can influence PAF-CPT activity of HMC.

scholarly journals Preliminary investigation on the use of allyl isothiocyanate to increase the shelf-life of gilthead sea bream (Sparus aurata) fillets

2015 ◽  
Vol 4 (3) ◽  
Author(s):  
Filippo Giarratana ◽  
Chiara Crinò ◽  
Daniele Muscolino ◽  
Chiara Beninati ◽  
Graziella Ziino ◽  
...  
Keyword(s):  
Shelf Life ◽  
Sparus Aurata ◽  
Preliminary Investigation ◽  
Allyl Isothiocyanate ◽  
Gilthead Sea Bream ◽  
Sea Bream ◽  
In Vitro Tests ◽  
Spoilage Bacteria ◽  
Fish Product

The aim of this work is to evaluate the activity of allyl isothiocyanate (AITC) against fish spoilage bacteria (specific spoilage organisms; SSOs) as well as its possible use in gilthead sea bream (<em>Sparus aurata</em>) fillets to extend their shelf-life. In this regard, in vitro tests are carried out in order to evaluate the inhibitory activity of AITC and its vapours on several strains of SSOs. The AITC effect on the shelflife of sea bream fillets was made by putting them in plastic trays hermetically closed with the addition AITC. Microbiological and sensorial evaluations were made on fish fillets during storage. Treated fillets maintained microbial populations at a significantly lower level compared with the control samples during storage, showing better sensorial characteristics. Therefore, the use of AITC’s vapours seems to be a new and interesting alternative way to increase fish product shelf-life.

Platelet-activating factor and the kidney

1986 ◽  
Vol 251 (1) ◽  
pp. F1-F11 ◽  
Author(s):  
D. Schlondorff ◽  
R. Neuwirth
Keyword(s):  
De Novo ◽  
Mesangial Cells ◽  
Biological Activities ◽  
Platelet Activating Factor ◽  
Calcium Ionophore ◽  
Initial Step ◽  
Renal Physiology ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Isolated Kidney

Platelet-activating factor (PAF) represents a group of phospholipids with the basic structure of 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine. A number of different cells are capable of producing PAF in response to various stimuli. The initial step of PAF formation is activation of phospholipase A2 in a calcium-dependent manner, yielding lyso-PAF. During this step arachidonic acid is also released and can be converted to its respective cyclooxygenase and lipoxygenase products. The lyso-PAF generated is then acetylated in position 2 of the glycerol backbone by a coenzyme A (CoA)-dependent acetyltransferase. An additional pathway may exist whereby PAF is generated de novo from 1-alkyl-2-acetyl-sn-glycerol by phosphocholine transferase. PAF inactivation in cells and blood is by specific acetylhydrolases. PAF exhibits a variety of biological activities including platelet and leukocyte aggregation and activation, increased vascular permeability, respiratory distress, decreased cardiac output, and hypotension. In the kidney PAF can produce decreases in blood flow, glomerular filtration, and fluid and electrolyte excretion. Intrarenal artery injection of PAF may also result in glomerular accumulation of platelets and leukocytes and mild proteinuria. PAF increases prostaglandin formation in the isolated kidney and in cultured glomerular mesangial cells. PAF also causes contraction of mesangial cells. Upon stimulation with calcium ionophore the isolated kidney, isolated glomeruli and medullary cells, and cultured mesangial cells are capable of producing PAF. The potential role for PAF in renal physiology and pathophysiology requires further investigation that may be complicated by 1) the multiple interactions of PAF, prostaglandins, and leukotrienes and 2) the autocoid nature of PAF, which may restrict its action to its site of generation.

Functional and Biochemical Characterization of Immunologically Derived Equine Platelet-Activating Factor

1985 ◽  
Vol 22 (4) ◽  
pp. 375-386 ◽  
Author(s):  
H. C. Wimberly ◽  
D. O. Slauson ◽  
N. R. Neilsen
Keyword(s):  
Functional Activity ◽  
Biochemical Characterization ◽  
Platelet Activating Factor ◽  
Biochemical Properties ◽  
Naturally Occurring ◽  
Rabbit Platelets ◽  
Rapid Reaction ◽  
Specific Challenge

Antigen-specific challenge of equine leukocytes induced the non-lytic release of a platelet-activating factor in vitro. The equine platelet-activating factor stimulated the release of serotonin from equine platelets in a dose-responsive manner, independent of the presence of cyclo-oxygenase pathway inhibitors such as indomethacin. Rabbit platelets were also responsive to equine platelet-activating factor. The release of equine platelet-activating factor was a rapid reaction with near maximal secretion taking place in 30 seconds. Addition of equine platelet-activating factor to washed equine platelets stimulated platelet aggregation which could not be inhibited by the presence of aspirin or indomethacin. Platelets preincubated with equine platelet-activating factor became specifically desensitized to equine platelet-activating factor while remaining responsive to other platelet stimuli such as collagen and epinephrine. The following biochemical properties of equine platelet-activating factor are identical to those properties of 1-0-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine (AGEPC): stability upon exposure to air and acid; loss of functional activity after basecatalyzed methanolysis with subsequent acylation that returned all functional activity; and identical relative mobilities on silica gel G plates developed with chloroform:methanol:water (65:35:6, volume/volume). The combined functional and biochemical characteristics of equine platelet-activating factor strongly suggest identity between this naturally occurring, immunologically derived equine factor and AGEPC.

Growth hormone as an in vitro phagocyte-activating factor in the gilthead sea bream ( Sparus aurata )

1997 ◽  
Vol 287 (3) ◽  
pp. 535-540 ◽  
Author(s):  
Josep Alvar Calduch-Giner ◽  
Ariadna Sitjà-Bobadilla ◽  
Pilar Alvarez-Pellitero ◽  
Jaume Pérez-Sánchez
Keyword(s):  
Growth Hormone ◽  
Sparus Aurata ◽  
Gilthead Sea Bream ◽  
Sea Bream

Confocal Microscopy Characterization of In Vitro Tests of Controlled Atmosphere Plasma Spraying Hydroxyapatite (CAPS-HA) Coatings

2003 ◽  
Vol 254-256 ◽  
pp. 319-322 ◽  
Author(s):  
Khiam Aik Khor ◽  
M. Espanol Pons ◽  
Gemma Bertran-Vidal ◽  
Núria Llorca-Isern ◽  
Michel Jeandin ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Plasma Spraying ◽  
In Vitro Tests ◽  
Controlled Atmosphere ◽  
Microscopy Characterization

Morphological and histological characterization of an ectopically mineralized structure in a gilthead sea bream Sparus aurata with opercular deformation

2019 ◽  
Vol 42 (9) ◽  
pp. 1259-1270
Author(s):  
Nguyen Phuc Thuong ◽  
Edina Prondvai ◽  
Barbara De Kegel ◽  
Tania De Wolf ◽  
Paul Eckhard Witten ◽  
...  
Keyword(s):  
Sparus Aurata ◽  
Gilthead Sea Bream ◽  
Sea Bream

scholarly journals Ecdysteroidogenesis in Heliothis virescens (Lepidoptera: Noctuidae): Recombinant Prothoracicotropic Hormone and Brain Extract Show Comparable Effects

2019 ◽  
Vol 19 (3) ◽  
Author(s):  
Marisa Nardiello ◽  
Rosanna Salvia ◽  
Andrea Scala ◽  
Carmen Scieuzo ◽  
Sabino Aurelio Bufo ◽  
...  
Keyword(s):  
Heliothis Virescens ◽  
Complex Mixture ◽  
Prothoracic Gland ◽  
Tobacco Budworm ◽  
Brain Extract ◽  
In Vitro Tests ◽  
Prothoracicotropic Hormone ◽  
Lepidoptera Noctuidae

Abstract Prothoracicotropic hormone (PTTH) is a neuropeptide that triggers a cascade of events within the prothoracic gland (PG) cells, leading to the activation of all the crucial enzymes involved in ecdysone biosynthesis, the main insect steroid hormone. Studies concerning ecdysteroidogenesis predicted PTTH action using brain extract (BE), consisting in a complex mixture in which some components positively or negatively interfere with PTTH-stimulated ecdysteroidogenesis. Consequently, the integration of these opposing factors in steroidogenic tissues leads to a complex secretory pattern. A recombinant form of prothoracicotropic hormone (rPTTH) from the tobacco budworm Heliothis virescens (F.) (Lepidoptera: Noctuidae) was expressed and purified to perform in vitro tests in a standard and repeatable manner. A characterization of rPTTH primary and secondary structures was performed. The ability of rPTTH and H. virescens BE to stimulate ecdysteroidogenesis was investigated on the third day of fifth larval stage. rPTTH activity was compared with the BE mixture by enzyme immunoassay and western blot, revealing that they equally stimulate the production of significant amount of ecdysone, through a transduction cascade that includes the TOR pathway, by the phosphorylation of 4E binding protein (4E-BP) and S6 kinase (S6K), the main targets of TOR protein. The results of these experiments suggest the importance of obtaining a functional pure hormone to perform further studies, not depending on the crude brain extract, composed by different elements and susceptible to different uncontrollable variables.

Sign in / Sign up

Export Citation Format

Share Document