Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 15543845

Blood platelets decrease concentration of reactive oxygen species produced by polymorphonuclear leukocytes.

V Jancinova·K Drabikova·M Petrikova·R Nosal
View original source ↗Export metadata ↓

Abstract

BACKGROUND: Reactive oxygen species produced by polymorphonuclear leukocytes (PMNL) participate substantially in vascular injury induced by ischaemia and reperfusion. Blood platelets, accumulated simultaneously with PMNL may modulate this process. OBJECTIVE: To compare effects of resting and completely stimulated platelets on PMNL-derived oxidants. METHODS: Autologous human platelets and PMNL were co-incubated in the physiological cell ratio 50:1, and the formation of reactive oxygen species was detected by luminol- and isoluminol-enhanced chemiluminescence methods. To compare effects of platelets at different degrees of their activation, FMLP (selective PMNL stimulus) and Ca2+-ionophore A23187 (activates both PMNL and platelets) were used as chemiluminescence stimuli. The liberation of serotonin from platelets was estimated fluorometrically. RESULTS: Both stimulated and non-stimulated platelets inhibited PMNL chemiluminescence. However, while the decreasing effect of resting platelets disappeared at increased extracellular peroxidase concentration, the inhibition of chemiluminescence by activated platelets became even more pronounced after the addition of peroxidase and was accompanied by liberation of serotonin. The concentrations of serotonin released from platelets were sufficiently high to inhibit PMNL chemiluminescence. CONCLUSION: The obtained data indicate that by interference of platelets with peroxidase liberation from PMNL and the scavenging effect of platelet serotonin, resting and stimulated platelets might be respectively operative in inhibiting chemiluminescence. Since the presence of blood platelets in the proximity of PMNL effectively decreased the concentration of reactive oxygen species, platelets may represent a unique protective mechanism, active only in case of emergency and selectively at sites exposed to toxic effects of reactive oxygen species. (Tab. 1, Fig. 4, Ref. 42.).

Explore related subjects

Blood PlateletsCalcimycinHumansIndicators and ReagentsLuminescent MeasurementsLuminolN-Formylmethionine Leucyl-PhenylalanineNeutrophilsPlatelet ActivationReactive Oxygen SpeciesSerotoninJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

V Jancinova, K Drabikova, M Petrikova, R Nosal. 2004. Blood platelets decrease concentration of reactive oxygen species produced by polymorphonuclear leukocytes.. https://pubmed.ncbi.nlm.nih.gov/15543845/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

Dynamic lysine acetylation and succinylation of platelet proteins regulates platelet storage lesion: mechanistic insights from multi-omics.

OBJECTIVES: Platelet storage lesion (PSL) severely impairs platelet function during storage, presenting a major hurdle in transfusion medicine; however, the dynamic interplay between global proteomic changes and post-translational modifications (PTMs) underlying these functional deteriorations remains insufficiently characterized. Here, we report the first comprehensive multi-omics analysis integrating global proteomics, acetylomics, and succinylomics to dissect the molecular dynamics during platelet storage. METHODS: We performed quantification of global proteomics, acetylome and succinylome based on TMT-labeled LC-MS/MS analysis, combined with antibody-affinity enrichment and purification. Dynamic molecular changes and functional transformation of platelet were also characterized under proper conditions stored for 1, 3, 5, 7 days, respectively. RESULTS: We systematically characterized 3,609 proteins, 1,308 acetylation sites, and 1,947 succinylation sites across multiple storage time points (D1, D3, D5, D7). We distinct temporal patterns of post-translational modifications, with succinylation showing more extensive coverage than acetylation in platelets. Pathway enrichment analysis revealed extensive metabolic reprogramming involving complement activation, energy metabolism, and cellular detoxification processes. The identification of specific motif patterns provided mechanistic insights into the functional specificity of these modifications. Random forest machine learning identified 20 core regulatory proteins representing critical nodes in PSL development. Furthermore, we employed real - time quantitative polymerase chain reaction (RT - QPCR) to measure the expression levels of key genes related to platelet function and PTM - associated pathways. CONCLUSION: By mapping the interplay between proteomic abundance shifts and PTM dynamics, this study provides a multidimensional understanding of PSL, establishing a foundational framework for optimizing storage protocols and enhancing transfusion safety.

Blood Platelets↗
PubMed2006

Vasodilator-stimulated phosphoprotein (VASP) is phosphorylated on Ser157 by protein kinase C-dependent and -independent mechanisms in thrombin-stimulated human platelets.

VASP (vasodilator-stimulated phosphoprotein) is an actin- and profilin-binding protein that is expressed in platelets at high levels and plays a major role in negatively regulating secretory and adhesive events in these cells. VASP is a major substrate for cAMP- and cGMP-regulated protein kinases and it has been shown to be directly phosphorylated on Ser157 by PKC (protein kinase C). In the present paper, we show that, in human platelets, VASP is phosphorylated by PKC on Ser157, but not Ser239, in response to phorbol ester stimulation, in a manner blocked by the PKC inhibitor BIM I (bisindolylmaleimide I). In response to thrombin, VASP was also phosphorylated on Ser157, but this response was only partially inhibited by BIM I, indicating PKC-dependent and -independent pathways to VASP phosphorylation by thrombin. Using inhibitors, we have ruled out the possibility that the PKC-independent pathway acts through guanylate cyclase generation of cGMP, or through a phosphoinositide 3-kinase-dependent kinase. Inhibition of Rho kinase, however, substantially reduced Ser157 VASP phosphorylation, and its effects were additive with BIM I. This implicates Rho kinase and PKC as the major kinases that phosphorylate VASP Ser157 in response to thrombin in platelets.

Blood Platelets↗