Vascular endothelial growth factor-D modulates oxidant-antioxidant balance of human vascular endothelial cells.

Vascular endothelial growth factor-D (VEGF-D) is an angiogenic and lymphangiogenic glycoprotein that facilitates tumour growth and distant organ metastasis. Our previous studies showed that VEGF-D stimulates the expression of proteins involved in cell-matrix interactions and promoting the migration of endothelial cells. In this study, we focused on the redox homoeostasis of endothelial cells, which is significantly altered in the process of tumour angiogenesis.

Proteomic analysis of plasma profiles in children with recurrent bone fractures.

Unlabelled: The aim of the study is proteomic analysis of the plasma profile in children with recurrent bone fractures. The study involved 16 children: 6 patients with recurrent low-energy fractures and normal bone mass and 10 with osteogenesis imperfecta. In the analysis of the protein profile, the two-dimensional protein electrophoresis was used (Ettan DALT II, Amersham Bioscience).

Corpora amylacea from multiple sclerosis brain tissue consists of aggregated neuronal cells.

In this report, we describe proteomic analysis of corpora amylacea collected by postmortem laser microdissection from multiple sclerosis (MS) brain lesions. Using low level protein loads (about 30 microg), a combination of two-dimensional electrophoresis with matrix-assisted laser desorption/ionization-time of flight mass spectrometry and database interrogations we identified 24 proteins of suspected neuronal origin. In addition to major cytoskeletal proteins like actin, tubulin, and vimentin, we identified a variety of proteins implicated specifically in cellular motility and plasticity (F-actin capping protein), regulation of apoptosis and senescence (tumor rejection antigen-1, heat shock proteins, valosin-containing protein, and ubiquitin-activating enzyme E1), and enzymatic pathways (glyceraldehyde-3-dehydrogenase, protein disulfide isomerase, protein disulfide isomerase related protein 5, lactate dehydrogenase).

Expression of Integrins and Adhesive Properties of Human Endothelial Cell Line EA.hy 926.

Immortalized endothelial cell lines are very often used as a model of endothelium for studies of various processes connected with its functions. Among the hybrid cells, the EA.hy 926 cell line, derived by the fusion of HUVECs with the continuous human lung carcinoma cell line A549, is presently the best characterized macro-vascular endothelial cell line.

Heat shock proteins and other components of cellular machinery for protein synthesis are up-regulated in vascular endothelial cell growth factor-activated human endothelial cells.

Proteome analysis of human umbilical endothelial cells was performed to identify proteins that are modified during vascular endothelial cell growth factor (VEGF)-induced transition from the quiescent into the proliferating-migrative phenotype. Subtractive analysis of two-dimensional gel patterns of human endothelial cells, before and after stimulation with VEGF(165), revealed differences in 85 protein spots. All proteins were identified by peptide sequencing and peptide mass fingerprinting using an electrospray spectrometer.

Comparison of platelet aggregability and P-selectin surface expression on platelets isolated by different methods.

Three methods commonly used for isolation of blood platelets from plasma were compared. Platelets were isolated by: 1) a washing method; 2) a method of metrizamide-gradient centrifugation; 3) a modified method of gel-filtration. The last method employed BSA-Sepharose gel instead of routinely used Sepharose gel saturated with BSA.

Release of calcium and P-selectin from intraplatelet granules is hampered by procaine.

The inhibition of platelets by some local anaesthetics has been related to the modulation of platelet membrane lipid fluidity, and one of these compounds, procaine, has been proven to be particularly effective inhibitor. In the present study, we examined the effect of procaine on the mobilization of intracellular granule contents in isolated washed platelets. We revealed that the presence of 10 mg/ml procaine significantly hampered platelet release reaction, as demonstrated by the significant reduction in the expression of platelet P-selectin (CD62) on one hand, and significantly enhanced expression of GPIb alpha (CD42b) antigen on the other, following either 1 hour incubation of washed platelets at room temperature (%CD62: 37.

Platelet membrane fluidity and intraplatelet Ca2+ mobilization are affected in uraemia.

In present investigations, platelet membrane fluidity and intraplatelet Ca2+ mobilization were analysed in uraemic platelets by fluorescence techniques. Thirteen non-dialyzed uraemic patients and 16 control subjects were examined. Anisotropy of DPH-probe, measured at 37 degrees C, was significantly higher in control (0.

Inhibition of tongue reflex in rats by tooth pulp stimulation during cerebral ventricle perfusion with (6-11) substance P analogs.

The effect of 12 C-terminal hexapeptide analogs of substance P perfused into the cerebral ventricles on the trigemino-hypoglossal reflex caused by incisor pulp stimulation in rats was investigated. A substitution of the L-isomer by D at position 6, 7, or 8 of the substance P analogs used in this study caused the most pronounced inhibition of the trigemino-hypoglossal reflex. A correlation between the degree of inhibition of the reflex and concentration of the peptide used was observed.

Changes in platelet response to adenosine 5'-diphosphate caused by verapamil.

Verapamil is widely used in the treatment of patients with coronary artery disease. The effect of verapamil on vascular smooth muscle cells is well documented. This effect is mediated by the inhibition of calcium fluxes across plasma membranes.

Platelet membrane fluidity and intraplatelet Ca2+ homeostasis are affected in uremia.

Recently we have described a dependence of platelet disability in thrombosis upon the progression in renal failure and an elevated level of RGDS-containing degradation products in uremic plasma, which is also correlated with progression in renal failure. Based on fluorescence techniques, our present investigations concerned possible changes in platelet membrane fluidity and intraplatelet calcium homeostasis in uremic platelets. Washed platelets loaded with DPH or with Fura-2 were examined with LS-50 luminescence spectrometer.

Concentration of RGDS-containing degradation products in uremic plasma is correlated with progression in renal failure.

A concentration of protein degradation products containing the RGDS sequence, which could contribute to a lower reactivity of uremic platelets, has been estimated in both uremic (n = 16) and control (n = 7) plasmas. Degradation products and other small molecules were separated from plasma by filtration through AMICON YM-10 filter. RGDS antigen was determined in filtered material using the radioimmunoassay method based on monospecific anti-RGDS rabbit polyclonal antibodies.

Central activity of peptide Gly-Pro-Hyp--the main component of collagen degradation products mixture.

The effect of tripeptide Gly-Pro-Hyp on the central nervous system was studied. The peptide Gly-Pro-Hyp is a main component of the mixture of collagen type I degradation products obtained by 6-h digestion with bacterial collagenase. The investigated peptide in the doses 1 microgram, 2 micrograms, and 5 micrograms significantly reduces the psychomotor activity of animals, intensifies haloperidol-induced catalepsy and enhances stereotypy behaviour after apomorphine administration.

The 3-7 fragment of angiotensin II is probably responsible for its psychoactive properties.

The abilities of angiotensin II-(3-7)-pentapeptide (A-II-(3-7), 1 nmol) and angiotensin II (A-II, 1 nmol) to influence rat's psychomotor and cognitive behaviours were compared. Both peptides, given intracerebroventricularly (i.c.

Effects of N- and C-terminal fragments of substance P on ATPase and monoamine oxidase activities in rat brain.

The in vitro influence of substance P (SP) C- and N-terminal fragments on the Na+,K(+)-ATPase and Ca2+,Mg2(+)-ATPase and monoamine oxidase (MAO) from synaptosomal membrane and extra-synaptosomal mitochondria were studied. The obtained results indicate: 1. C-terminal fragment of SP (SP6-11) in 10 microM concentration stimulates the Ca2+,Mg2(+)-ATPase activities from cerebral cortex and hippocampus.

Delta-sleep inducing peptide (DSIP) and its fragments as the modulators of neural transmission in the central nervous system.

The present study is a continuation of our previous experiments on DSIP activity which have revealed that nonapeptide DSIP inhibits hippocampal electrical activity of the 4-7 c/s frequency band. The aim of the present study was to find which of the known DSIP fragments is responsible for its activity, i.e.

Psychotropic activity of angiotensin II and its fragments Val-Tyr-Ile-NH2 and Val-Tyr-Ile-His-NH2.

Angiotensin II (A II) significantly enhanced the motor activity of rats in the open field as measured by forward locomotion, rearings and bar approaches while the tripeptide [A II(3-5)] and the tetrapeptide [A II(3-6)] were ineffective in this test. Also, the stereotyped behavior produced by apomorphine (2 mg/kg) or amphetamine (6.5 mg/kg), both given intraperitoneally, was significantly more intense in rats receiving an icv injection of A II but not A II(3-5) or A II(3-6).

Synthesis and biological activity of substance P C-terminal hexapeptide analogues: structure-activity studies.

The synthesis of six hexapeptide analogues of C-terminal Substance P fragment containing alpha, beta-dehydrophenylalanine (delta Phe) in the position 7 or 8 is described. The effect of the structural changes on the hypotensive activity and antigenic properties of analogues was compared. It was found that substitution of delta Phe in various analogues of C-terminal hexapeptide of Substance P resulted in different effects on the hypotensive activity.

Hypotensive activity of histidine-containing analogues of C-terminal hexapeptide of substance P.

Four new hexapeptide analogues of C-terminal Substance P fragment with increased solubility in aqueous solutions are described. The peptides contain histidine in positions 6, 8, 9 and 10, respectively. The effect of the structural changes on the hypotensive activity and antigenic properties of analogues was compared.

Specificity of antisera obtained to substance P and its C-terminal hexapeptide.

Synthetic fragments and analogs were used to characterize specificity of antisera to SP and SP6-11. [Tyr8] SP and [Lys6] SP6-11 were both used as radioiodinated ligands. The latter was conjugated with Bolton-Hunter reagents before labelling.

The preliminary evaluation of degradation of substance P(SP) fragment's analogue less than Glu SP6-11 in the subcellular fractions from different areas of rat brain.

Peptidase(s) activity of different subcellular fractions isolated from cortex, hippocampus, midbrain, thalamus with hypothalamus, cerebellum and medulla oblongata exerted against less than Glu SP6-11 (3H-Phen8) was evaluated in "low-ionic" and similar (in composition) to both extracellular and intracellular conditions. The incubation of less than Glu SP6-11 with different fractions leaves the hexapeptide undegraded in the studied conditions in most cases. Peptidases activity results in the formation of the first of all C-terminal and exceptionally "internal" labelled products.

Effects of analogues of substance P fragments on the MAO activity in rat brain.

The influence in vitro of analogues of Sp5-11 and SP6-11 substance P fragments on the activity of monoamine oxidase (MAO) in homogenates and crude mitochondrial fractions of rat brain was examined. The rat brain was divided into: I--cerebral cortex, II--hippocampus, III--midbrain, IV--thalamus with hypothalamus, V--cerebellum and VI--medulla oblongata. The obtained results proved that the analogues of SP fragments inhibit selectively the activity of the enzyme in the homogenates of cerebral cortex, hippocampus, midbrain and cerebellum.

Immunochemical analysis of substance P using its synthetic fragments and analogs.

Synthetic fragments and analogs were used to characterize specificity of antisera to substance P. Both, the C-terminal hexapeptide and the pentapeptide completely inhibited binding of 125I-[Tyr8]substance P by these antisera, showing the antigenic identity with substance P. Synthetic fragments shorter than peptide (7-11) did not react with anti-substance P antisera in this system.