An Evaluation of Platelet Factor 4, Beta-Thromboglobulin and Mean Platelet Volume in the Assessment of Thrombotic Risks in Subjects with Diabetes Mellitus at Lagos State University Teaching Hospital, Ikeja, Lagos, Nigeria.

BACKGROUND: Beta-thromboglobulin and platelet factor 4 are known platelet-specific proteins that are stored in the platelet alpha-granules and released during platelet activation. The measurement of these proteins can reflect the degree of platelet activation and indirectly suggest a pro-thrombotic state. This study aimed at determining serum levels of Betathromboglobulin, mean platelet volume, and platelet factor 4 in diabetes mellitus and control subjects in Lagos, Nigeria. MATERIALS AND METHODS: Using enzyme-linked immunosorbent assay at Lagos State University Teaching Hospital, Ikeja, this study evaluated serum concentrations of Beta-thromboglobulin, and platelet factor 4, the mean platelet volume was also determined from a Full Blood Count of all participants. Data were analyzed using Statistical Package for Social Sciences, Inc., Chicago, Ill; version 26.0. The continuous variables were given as mean ± standard deviation. The P-value was considered to be statistically significant when ≤0.05. RESULTS: Beta-thromboglobulin concentration was higher and statistically significant (7.82 ± 1.54ng/ml and 6.70 ± 2.23 ng/ml; P = 0.01), platelet factor 4 (39.86 ± 11.25 ng/ml and 47.73 ± 21.73ng/ml, P = 0.06) and mean platelet volume (10.26± 1.06fl and 10.29 ± 1.02fl P = 0.89) were not statistically significant in the diabetes mellitus group compared with non-diabetic participants, platelet factor 4 was higher in the older than younger diabetes mellitus participants. CONCLUSION: Elevated Beta-thromboglobulin may suggest a possible increase in thrombotic risks among diabetes mellitus.

CONTEXTE: La bêta-thromboglobuline et le facteur plaquettaire 4 sont des protéines spécifiques des plaquettes qui sont stockées dans les alpha-granules plaquettaires et libérées lors de l'activation des plaquettes. La mesure de ces protéines peut refléter le degré d'activation des plaquettes et suggérer indirectement un état prothrombotique. Cette étude visait à déterminer les taux sériques de bêta-thromboglobuline, le volume plaquettaire moyen et le facteur plaquettaire 4 chez des sujets atteints de diabète sucré et des sujets témoins à Lagos, au Nigéria. MATÉRIEL ET MÉTHODES: En utilisant le dosage immunoenzymatique au Lagos State University Teaching Hospital, Ikeja, cette étude a évalué les concentrations sériques de bêtathromboglobuline et de facteur plaquettaire 4, le volume plaquettaire moyen a également été déterminé à partir d'une numération globulaire complète de tous les participants. Les données ont été analysées à l'aide du logiciel Statistical Package for Social Sciences, Inc, Chicago,Ill ; version 26.0. Les variables continues ont été exprimées en moyen ± écart-type. La valeur P a été considérée comme statistiquement significative lorsqu'elle était inférieure à ≤0,05. RÉSULTATS: La concentration de bêta-thromboglobuline était plus élevée et statistiquement significative (7,82±1,54ng/ml et 6,70±2,23 ng/ml ; P=0,01), le facteur plaquettaire 4 (39,86±11,25 ng/ml et 47,73±21,73 ng/ml, P=0,06) et le volume plaquettaire moyen (10. 26± 1.06fl et 10.29±1.02fl P= 0.89) n'étaient pas statistiquement significatifs dans le groupe diabète sucré par rapport aux participants non-diabétiques, le facteur plaquettaire 4 était plus élevé chez les participants diabétiques plus âgés que chez les plus jeunes. CONCLUSION: Un taux élevé de bêta-thromboglobuline peutsuggérer une augmentation possible des risques thrombotiques chez les personnes atteintes de diabète sucré. Mots-clés: Bêta-thromboglobuline, facteur plaquettaire 4, volume plaquettaire moyen.

Serum amyloid P component and pro-platelet basic protein in extracellular vesicles or serum are novel markers of liver fibrosis in chronic hepatitis C patients.

Extracellular vesicles (EVs) contain proteins, mRNAs, and microRNAs, and their cargos have emerged as novel diagnostic markers in various diseases. We aimed to discover novel and noninvasive biomarkers of liver fibrosis by proteomic analysis using serum EVs in patients with chronic hepatitis C. We performed shotgun proteomics using serum EVs isolated from 54 patients with histologically assessed liver fibrosis. Shotgun proteomics identified a total of 974 proteins, and 445 proteins were detected in more than half of the patients. Among them, a total of 9 proteins were identified as proteins that tended to increase or decrease with liver fibrosis with a significance of p<0.005 and that were different between F1-2 patients and F3-4 patients with a significance of p<0.01. Among the 9 proteins, targeted proteomics using serum EVs isolated from the sera of another 80 patients with histologically assessed liver fibrosis verified that serum amyloid P component (SAP) and pro-platelet basic protein (PPBP) levels in EVs significantly decreased with the progression of liver fibrosis and were significantly lower in F3-4 patients than in F1-2 patients. The diagnostic accuracies of SAP and PPBP in EVs for the liver fibrosis stage were comparable to those of type IV collagen 7S, hyaluronic acid, and the fibrosis-4 index (FIB-4 index). Moreover, serum SAP and PPBP levels correlated with the levels in EVs, and the ability of serum SAP and PPBP to diagnose liver fibrosis stage was also comparable to the abilities of type IV collagen 7S, hyaluronic acid, and the FIB-4 index. In conclusion, proteomic analysis of serum EVs identified SAP and PPBP as candidate biomarkers for predicting liver fibrosis in patients with chronic hepatitis C. In addition, SAP and PPBP levels in serum are strongly correlated with those in EVs and could represent markers of liver fibrosis.

Monocytes secrete CXCL7 to promote breast cancer progression.

Certain immune cells and inflammatory cytokines are essential components in the tumor microenvironment to promote breast cancer progression. To identify key immune players in the tumor microenvironment, we applied highly invasive MDA-MB-231 breast cancer cell lines to co-culture with human monocyte THP-1 cells and identified CXCL7 by cytokine array as one of the increasingly secreted cytokines by THP-1 cells. Further investigations indicated that upon co-culturing, breast cancer cells secreted CSF1 to induce expression and release of CXCL7 from monocytes, which in turn acted on cancer cells to promote FAK activation, MMP13 expression, migration, and invasion. In a xenograft mouse model, administration of CXCL7 antibodies significantly reduced abundance of M2 macrophages in tumor microenvironment, as well as decreased tumor growth and distant metastasis. Clinical investigation further suggested that high CXCL7 expression is correlated with breast cancer progression and poor overall survival of patients. Overall, our study unveils an important immune cytokine, CXCL7, which is secreted by tumor infiltrating monocytes, to stimulate cancer cell migration, invasion, and metastasis, contributing to the promotion of breast cancer progression.

Type 2 Diabetes Coagulopathy Proteins May Conflict With Biomarkers Reflective of COVID-19 Severity.

Objective: Detailed proteomic analysis in a cohort of patients with differing severity of COVID-19 disease identified biomarkers within the complement and coagulation cascades as biomarkers for disease severity has been reported; however, it is unclear if these proteins differ sufficiently from other conditions to be considered as biomarkers. Methods: A prospective, parallel study in T2D (n = 23) and controls (n = 23). A hyperinsulinemic clamp was performed and normoglycemia induced in T2D [4.5 ± 0.07 mmol/L (81 ± 1.2 mg/dl)] for 1-h, following which blood glucose was decreased to ≤2.0 mmol/L (36 mg/dl). Proteomic analysis for the complement and coagulation cascades were measured using Slow Off-rate Modified Aptamer (SOMA)-scan. Results: Thirty-four proteins were measured. At baseline, 4 of 18 were found to differ in T2D versus controls for platelet degranulation [Neutrophil-activating peptide-2 (p = 0.014), Thrombospondin-1 (p = 0.012), Platelet factor-4 (p = 0.007), and Kininogen-1 (p = 0.05)], whilst 3 of 16 proteins differed for complement and coagulation cascades [Coagulation factor IX (p < 0.05), Kininogen-1 (p = 0.05), and Heparin cofactor-2 (p = 0.007)]; STRING analysis demonstrated the close relationship of these proteins to one another. Induced euglycemia in T2D showed no protein changes versus baseline. At hypoglycemia, however, four proteins changed in controls from baseline [Thrombospondin-1 (p < 0.014), platelet factor-4 (p < 0.01), Platelet basic protein (p < 0.008), and Vitamin K-dependent protein-C (p < 0.00003)], and one protein changed in T2D [Vitamin K-dependent protein-C, (p < 0.0002)]. Conclusion: Seven of 34 proteins suggested to be biomarkers of COVID-19 severity within the platelet degranulation and complement and coagulation cascades differed in T2D versus controls, with further changes occurring at hypoglycemia, suggesting that validation of these biomarkers is critical. It is unclear if these protein changes in T2D may predict worse COVID-19 disease for these patients. Clinical Trial Registration: https://clinicaltrials.gov/, identifier NCT03102801.

Exploring the changes of brain immune microenvironment in Alzheimer's disease based on PANDA algorithm combined with blood brain barrier injury-related genes.

Studies have shown that the specific entry of peripheral cells into the brain parenchyma caused by BBB injury and the imbalance of the immune microenvironment in the brain are closely related to the pathogenesis of Alzheimer's disease (AD). Because of the difficulty of obtaining data inside the brain, it is urgent to find out the relationship between the peripheral and intracerebral data and their influence on the development of AD by machine learning methods. However, in the actual algorithm design, it is still a challenge to extract relevant information from a variety of data to establish a complete and accurate regulatory network. In order to overcome the above difficulties, we presented a method based on a message passing model (Passing Attributes between Networks for Data Assimilation, PANDA) to discover the correlation between internal and external brain by the BBB injury-related genes, and further explore their regulatory mechanism of the brain immune environment for AD pathology. The Biological analysis of the results showed that pathways such as immune response pathway, inflammatory response pathway and chemokine signaling pathway are closely related to the pathogenesis of AD. Especially, some significant genes such as RELA, LAMA4, PPBP were found play certain roles in the injury of BBB and the change of permeability in AD patients, thus leading to the change of immune microenvironment in AD brain.

Differential Effects of Clopidogrel With or Without Aspirin on Platelet Reactivity and Coagulation Activation: A Randomized Trial in Healthy Volunteers.

Dual antiplatelet therapy (DAPT) is standard in acute coronary syndrome but confers a bleeding risk. To compare effects of clopidogrel single antiplatelet therapy (SAPT) with clopidogrel-based DAPT on hemostatic system activation we conducted a randomized clinical trial in 44 volunteers (clopidogrel (d1: 600 mg, d2-6: 150 mg) ± aspirin (100 mg)). Multiple electrode aggregometry-adenosine diphosphate (MEA-ADP) and MEA-arachidonic acid (MEA-AA) triggered aggregometry, vasodilator-stimulated phosphoprotein (VASP), beta thromboglobulin, p-selectin, thromboxane B2 , d-Dimer, prothrombin fragment 1.2 (f1.2), and a phospholipid-dependent clotting time were measured in venous blood. Changes are described by mean differences (Δmean (95% confidence interval (CI)) or geometric mean ratios (95% CI)). DAPT and SAPT comparably and significantly decreased MEA-ADP at 2 hours (-60% vs. -63%; P = 0.35, Δmean -4.9, 95% CI -15.4 to 5.5). At 24 hours (-59% vs. -47%, P = 0.04, Δmean -11.1, 95% CI -21.7 to -0.4]) and 8 days (-61% vs. -53%, P = 0.04, Δmean -11.3, 95% CI -22.0 to -0.6). Both treatments significantly reduced VASP and MEA-AA after 2 hours and 8 days. DAPT inhibited MEA-AA significantly stronger at 2 hours (-77% vs. -30%; P < 0.0001, Δmean -39.6, 95% CI -54.2 to -25.0), at 24 hours (-80% vs. -27%, P < 0.0001, Δmean -47.8, 95% CI -62.3 to -33.3), and 8 days (-79% vs. -27%, P < 0.0001, Δmean -48.9, 95% CI -62.5 to -35.4). Neither treatment significantly influenced beta thromboglobulin or p-selectin. DAPT abolished and SAPT reduced thromboxane B2 after 24 hours and 8 days. The d-Dimer was reduced by DAPT (0.94, 95% CI 0.89-1.00, P = 0.04) at 2 hours but not after 24 hours and 8 days. SAPT did not decrease d-Dimer. Neither treatment affected f1.2. DAPT and SAPT comparably affect platelet and coagulation activation in venous blood.

Increased Plasma Levels of Platelet Factor 4 and ß-thromboglobulin in Women with Recurrent Pregnancy Loss.

Thrombosis in decidual vessels is one of the mechanisms of pregnancy loss. However, few studies have assessed the relation between platelet activation, which is known to cause of thrombosis, and recurrent pregnancy loss (RPL). We investigated platelet activation in women with RPL compared to controls by measuring plasma levels of platelet factor 4 (PF4) and ß-thromboglobulin (ßTG), and assessed correlations between PF4/ßTG and coagulative risk factors associated with RPL. The study group included 135 women who had experienced two or more consecutive pregnancy losses. The control group included 28 age-matched healthy women who had never experienced pregnancy loss. PF4 and ßTG plasma levels were significantly higher in the women with RPL than controls (PF4: 14.0 [8.0-20.0] vs. 9.0 [6.0-12.0] ng/ml, p=0.043; ßTG: 42.0 [24.3-59.8] vs. 31.5 [26.6-36.4] ng/ml, p=0.002). There was a significant association between ßTG and anti-phosphatidylethanolamine antibody immunoglobulin M (aPE IgM) (p=0.048). Among the women with RPL, 18 of those who were positive for PF4 (45%) and 18 of those who were positive for ßTG (37%) were negative for all known coagulative risk factors associated with RPL. Measurements of PF4 and ßTG may be important because they help identify women who are at risk of RPL.

Hemocompatibility Testing of Blood-Contacting Implants in a Flow Loop Model Mimicking Human Blood Flow.

The growing use of medical devices (e.g., vascular grafts, stents, and cardiac catheters) for temporary or permanent purposes that remain in the body's circulatory system demands a reliable and multiparametric approach that evaluates the possible hematologic complications caused by these devices (i.e., activation and destruction of blood components). Comprehensive in vitro hemocompatibility testing of blood-contacting implants is the first step towards successful in vivo implementation. Therefore, extensive analysis according to the International Organization for Standardization 10993-4 (ISO 10993-4) is mandatory prior to clinical application. The presented flow loop describes a sensitive model to analyze the hemostatic performance of stents (in this case, neurovascular) and reveal adverse effects. The use of fresh human whole blood and gentle blood sampling are essential to avoid the preactivation of blood. The blood is perfused through a heparinized tubing containing the test specimen by using a peristaltic pump at a rate of 150 mL/min at 37 °C for 60 min. Before and after perfusion, hematologic markers (i.e., blood cell count, hemoglobin, hematocrit, and plasmatic markers) indicating the activation of leukocytes (polymorphonuclear [PMN]-elastase), platelets (ß-thromboglobulin [ß-TG]), the coagulation system (thombin-antithrombin III [TAT]), and the complement cascade (SC5b-9) are analyzed. In conclusion, we present an essential and reliable model for extensive hemocompatibility testing of stents and other blood-contacting devices prior to clinical application.

The Clinicopathological Significance of the CXCR2 Ligands, CXCL1, CXCL2, CXCL3, CXCL5, CXCL6, CXCL7, and CXCL8 in Gastric Cancer.

BACKGROUND/AIM: We have previously reported that chemokine (C-X-C motif) receptor 2 (CXCR2) signaling was associated with the malignant progression of gastric cancer (GC). We thus examined the clinicopathological significance of CXCR2 ligands, CXCL1, CXCL2, CXCL3, CXCL5, CXCL6, CXCL7, and CXCL8, in GC. PATIENTS AND METHODS: The expression of CXCR2 ligands in 590 GC cases was investigated by immunohistochemistry. RESULTS: The expression was as follows: CXCL1, 46.2% (257/557); CXCL2, 20.7% (122/590); CXCL3, 17.1% (101/589); CXCL5/CXCL6, 2.9% (17/589); CXCL7, 36.4% (215/590); and CXCL8 1.7% (10/585) of the cases. High invasion depth was correlated with CXCL1 expression. Lymph node metastasis and peritoneal cytology positivity were correlated with high expression of CXCL1 and CXCL7. The prognoses of the CXCL1-positive patients were significantly poorer than those of the CXCL1-negative patients (p<0.001). CONCLUSION: Among the CXCR2 ligands, CXCL7 and especially CXCL1, might play an important role in the malignant progression of GC via CXCR2 signaling.

Comprehensive lipidomic, metabolomic and proteomic profiling reveals the role of immune system in vitiligo.

BACKGROUND: Vitiligo is a common depigmentation disorder resulting from destruction of melanocytes, and has both genetic and environmental influences. Although genomic analyses have been performed to investigate the pathogenesis of vitiligo, the lipidomics, metabolomics and proteomics of serum have not been reported, and the role of small molecules and serum proteins in vitiligo remains unknown. AIM: To study the metabolite and protein profiles in patients with vitiligo and healthy controls (HCs). METHODS: Plasma samples from 60 participants (29 patients with vitiligo and 31 HCs) were analysed. Untargeted lipidomics, metabolomics and isobaric tags for relative and absolute quantification-based proteomics were performed using high performance liquid chromatography-tandem mass spectrometry. In addition, to validate differentially expressed metabolites in patients with vitiligo, plasma enzyme-linked immunosorbent assay was performed. RESULTS: We identified differential expression of several metabolites and proteins involved in the immune system. Among these metabolites and proteins, lysophosphatidylcholine, platelet-activating factor, sn-glycerol-3-phosphocholine, succinic acid, CXCL4 and CXCL7 were significantly elevated in the plasma of patients with vitiligo, while aspartate was downregulated. CONCLUSION: Our study has characterized several serum metabolites and proteins that could be potential candidate biomarkers in vitiligo, and provides a comprehensive insight into the role of immune system and aspartate metabolism in vitiligo.

Plasma NAP-2 levels are associated with critical limb ischemia in peripheral arterial disease patients.

IMPACT STATEMENT: Critical limb ischemia (CLI) is a serious arterial obstruction, resulting in serious reduction of blood flow to the extremities. CLI is a symptomatic disorder and is frequently not diagnosed in time. This results in a high mortality and elevated risk of limb amputation. Serum or plasma biomarkers play important roles in disease prevention, diagnosis, and prognosis. Elevated plasma neutrophil-activating peptide-2 (NAP-2) was found independently associated with CLI, but not with T2DM. Plasma NAP-2 levels might be an early CLI diagnostic biomarker and might provide a novel target for CLI treatment.

Investigation of the Underlying Genes and Mechanism of Macrophage-Enriched Ruptured Atherosclerotic Plaques Using Bioinformatics Method.

AIM: The study aimed to identify the underlying differentially expressed genes (DEGs) and mechanism of macrophage-enriched rupture atherosclerotic plaque using bioinformatics methods. METHODS: GSE41571, which includes six stable samples and five ruptured atherosclerotic samples, was downloaded from the GEO database. After preprocessing, DEGs between ruptured and stable atherosclerotic samples were identified using LIMMA. Gene Ontology biological process (GO_BP) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of DEGs were performed using the Database for Annotation, Visualization, and Integration Discovery (DAVID) online tool. Based on the STRING database, protein-protein interactions (PPIs) network among DEGs were constructed. Regulatory relationships between miRNAs/transcriptional factors (TFs) and target genes were predicted using Enrichr, and regulatory networks were visualized using Cytoscape. RESULTS: A total of 268 DEGs (64 up-regulated and 204 down-regulated DEGs) were identified between ruptured and stable samples. In the PPI network, collagen type III alpha 1 chain (COL3A1), collagen type I alpha 2 chain (COL1A2), and asporin (ASPN) were more than 15 interaction degrees. In the miRNA-target network, miR21 was highlighted with highest degrees and ASPN could be targeted by miR21. Functional enrichment analysis showed that COL3A1 and COL1A2 were significantly enriched in extracellular matrix organization and cell adhesion GO_BP terms. Pre-platelet basic protein (PPBP) was the most significantly up-regulated gene in ruptured atherosclerotic samples and enriched in immune response and inflammatory response GO_BP terms. CONCLUSIONS: Down-regulated COL3A1, COL1A2 and ASPN, and up-regulated PPBP might perform critical promotional roles in atherosclerotic plaque rupture. Furthermore, miR21 might be potential target to prevent atherosclerotic rupture.

Elevated beta-thromboglobulin and mean platelet volume levels may show persistent platelet activation in systemic lupus erythematosus patients.

BACKGROUND: Patients with systemic lupus erythematosus (SLE) have an increased risk of thrombotic events. Platelets become more active and they enlarge to release proteins from alpha granules for aggregation during the plaque formation period. Beta-thromboglobulin is one of the proteins released from alpha-granules when platelets are activated and used as a marker of platelet activation in vivo. OBJECTIVES: The aim of this study was to evaluate the plasma levels of beta-thromoglobulin and mean platelet volume as markers of the presence of platelet activation in systemic lupus erythematosus patients compared with healthy controls. MATERIAL AND METHODS: Thirty-seven SLE patients with a mean disease duration of 4.96 years and without any organ involvement as well as 30 healthy volunteers were included in the study. All patients were in remission of SLE. RESULTS: The mean beta-thromboglobulin level was 97.36 ±55.8 ng/mL in the SLE group and 72.67 ±33.5 ng/mL in the control group (p = 0.029). The mean platelet volume level was 8.27 ±1.68 fL in the SLE group and 9.16 ±1.52 fL (p = 0.031) in the controls. CONCLUSIONS: Elevated beta-thromboglobulin levels in systemic lupus erythematosus patients may be associated with platelet activation in the early stages of disease, whereas lower mean platelet volume levels in the same population may be due to the effects of hydroxychloroquine and the inactivity of SLE.

Ubiquitin-dependent proteolysis of CXCL7 leads to posterior longitudinal ligament ossification.

Ossification of the posterior longitudinal ligament (OPLL), a spinal ligament, reduces the range of motion in limbs. No treatment is currently available for OPLL, which is why therapies are urgently needed. OPLL occurs in obesity, is more common in men, and has an onset after 40 years of age. The mechanisms underlying OPLL remain unclear. In this study, we performed a serum proteomic analysis in both OPLL patients and healthy subjects to identify factors potentially involved in the development of OPLL, and found reduced levels of a protein that might underlie the pathology of OPLL. We isolated the protein, determined its amino acid sequence, and identified it as chemokine (C-X-C motif) ligand 7 (CXCL7). Based on these proteomics findings, we generated a CXCL7 knockout mouse model to study the molecular mechanisms underlying OPLL. CXCL7-null mice presented with a phenotype of OPLL, showing motor impairment, heterotopic ossification in the posterior ligament tissue, and osteoporosis in vertebrate tissue. To identify the mechanisms of CXCL7 deficiency in OPLL, we searched for single nucleotide polymorphisms and altered DNA exons, but no abnormalities were found. Although miR-340 levels were found to be high in an miRNA array, they were insufficient to reduce CXCL7 levels. Ubiquitin C-terminal hydrolase1 (UCHL1) was found to be overexpressed in CXCL7-null mice and in the sera of patients with OPLL, and was correlated with OPLL severity. Post-translational modifications of proteins with ubiquitin and ubiquitin-like modifiers, orchestrated by a cascade of specialized ubiquitin activating enzyme (E1), ubiquitin conjugating enzyme (E2), and ubiquitin ligase (E3) enzymes, are thought to control a wide range of cellular processes, and alterations in the ubiquitin-proteasome system have been associated with several degenerative disorders. In addition, the OPLL tissue of CXCL7-null mouse and its primary cells expressed the antibody to ubiquitin (linkage-specific K48). Our data clearly show decreased CXCL7 levels in patients with OPLL, and that OPLL developed in mice lacking CXCL7. Tumor necrosis factor receptor-associated factor (TRAF)6 expression was decreased in CXCL7-null mouse primary cells. Furthermore, K48 polyubiquitination was found in posterior longitudinal ligament ossified tissue and primary cells from CXCL7-null mice. We performed a phosphoproteomics analysis in CXCL7-deficient mice and identified increased phosphorylation of mitogen-activated protein kinase kinase (ME3K)15, ubiquitin protein ligase E3C (UBE3C) and protein kinase C (PKC) alpha, suggesting that ubiquitin-dependent degradation is involved in CXCL7 deficiency. Future studies in the CXCL7-null mouse model are, therefore, warranted to investigate the role of ubiquitination in the onset of OPLL. In conclusion, CXCL7 levels may be useful as a serum marker for the progression of OPLL. This study also suggests that increasing CXCL7 levels in patients can serve as an effective therapeutic strategy for the treatment of OPLL.

rLj-RGD3, a novel recombinant toxin protein from Lampetra japonica, prevents coronary thrombosis-induced acute myocardial infarction by inhibiting platelet functions in rats.

Recombinant Lampetra japonica RGD-peptide (rLj-RGD3), a soluble protein containing three RGD sequences, was acquired from the oral salivary glands of Lampetra japonica using recombinant DNA technology. The aim of this study was to investigate the protective effects of rLj-RGD3 against acute myocardial infarction (AMI) induced by coronary artery thrombosis, as well as the underlying mechanisms. A rat model of AMI caused by ferric chloride-induced thrombosis on the surface of the left anterior descending (LAD) coronary artery was successfully established. Rats were given various doses of rLj-RGD3 (12 µg/kg, 24 µg/kg and 48 µg/kg) via sublingual intravenous delivery 10 min before AMI. ST segment elevation was recorded by electrocardiogram (ECG) until the end of the model. Left ventricular Evans blue content and histopathological changes were examined. Blood samples were collected to determine 5-hydroxytryptamine (5-HT), ß-thromboglobulin (ß-TG), platelet factor 4 (PF4) and cAMP levels. The effects of rLj-RGD3 on platelet aggregation, adhesion and intracellular calcium concentrations were also measured. rLj-RGD3 significantly reduced ST segment elevation, prevented thrombus formation in the coronary artery and decreased Evans blue content in the left ventricular myocardium. Meanwhile, rLj-RGD3 exerted an inhibitory effect on adenosine diphosphate (ADP)-induced platelet aggregation and blocked platelet adhesion to collagen. Treatment with rLj-RGD3 prevented 5-HT, ß-TG and PF4 release and significantly elevated intracellular cAMP levels in a dose-dependent manner but decreased the level of cytosolic-free Ca2+, an aggregation-inducing molecule. These results show that rLj-RGD3 can effectively reduce coronary thrombosis in AMI rats by strongly inhibiting platelet function, indicating that the recombinant RGD toxin protein rLj-RGD3 may serve as a potent clinical therapeutic agent for AMI.

The mechanisms how heparin affects the tumor cell induced VEGF and chemokine release from platelets to attenuate the early metastatic niche formation.

Metastasis is responsible for the majority of cancer associated fatalities. Tumor cells leaving the primary tumor and entering the blood flow immediately interact with platelets. Activated platelets contribute in different ways to cancer cell survival and proliferation, e.g. in formation of the early metastatic niche by release of different growth factors and chemokines. Here we show that a direct interaction between platelets and MV3 melanoma or MCF7 breast cancer cells induces platelet activation and a VEGF release in citrated plasma that cannot be further elevated by the coagulation cascade and generated thrombin. In contrast, the release of platelet-derived chemokines CXCL5 and CXCL7 depends on both, a thrombin-mediated platelet activation and a direct interaction between tumor cells and platelets. Preincubation of platelets with therapeutic concentrations of unfractionated heparin reduces the tumor cell initiated VEGF release from platelets. In contrast, tumor cell induced CXCL5 and CXCL7 release from platelets was not impacted by heparin pretreatment in citrated plasma. In defibrinated, recalcified plasma, on the contrary, heparin is able to reduce CXCL5 and CXCL7 release from platelets by thrombin inhibition. Our data indicate that different chemokines and growth factors in diverse platelet granules are released in tightly regulated processes by various trigger mechanisms. We show for the first time that heparin is able to reduce the mediator release induced by different tumor cells both in a contact and coagulation dependent manner.

Platelet Depletion Impairs Host Defense to Pulmonary Infection with Pseudomonas aeruginosa in Mice.

Platelets have been implicated in pulmonary inflammatory cell recruitment after exposure to allergic and nonallergic stimuli, but little is known about the role of platelets in response to pulmonary infection with Pseudomonas aeruginosa. In this study, we have investigated the impact of the experimental depletion of circulating platelets on a range of inflammatory and bacterial parameters, and their subsequent impact on mortality in a murine model of pulmonary infection with P. aeruginosa. P. aeruginosa infection in mice induced a mild, but significant, state of peripheral thrombocytopenia in addition to pulmonary platelet accumulation. Increased platelet activation was detected in infected mice through increased levels of the platelet-derived mediators, platelet factor-4 and ß-thromboglobulin, in BAL fluid and blood plasma. In mice depleted of circulating platelets, pulmonary neutrophil recruitment was significantly reduced 24 hours after infection, whereas the incidence of systemic dissemination of bacteria was significantly increased compared with non-platelet-depleted control mice. Furthermore, mortality rates were increased in bacterial-infected mice depleted of circulating platelets. This work demonstrates a role for platelets in the host response toward a gram-negative bacterial respiratory infection.

ß-Thromboglobulin may not reflect platelet activation during haemodialysis with the HeprAN membrane.

BACKGROUND: When blood passes through the extracorporeal circuit during haemodialysis (HD) undesirable effects including platelet degranulation and coagulation activation take place. ß-thromboglobulin (ß-TG) is a sensitive marker of platelet activation. The aim of this study was to investigate platelet degranulation and coagulation activation during HD with the heparin-coated dialysis membrane HeprAN. METHODS: Four HD sessions were evaluated in each of 12 chronic HD patients. None of the patients used oral warfarin, other anticoagulants or antiplatelet drugs. In the first session the HeprAN membrane or a conventional polyflux membrane was used in a randomized manner and thereafter alternately in a cross-over design, and 50% of the conventional dalteparin dose was given at start of HD. Prothrombin fragment 1 + 2 (PF1 + 2), ß-TG and anti-factor Xa activity were measured repeatedly. RESULTS: No dialysis sessions were terminated early due to clotting of the extracorporeal system. Activation of intravascular coagulation as assessed by change in PF1 + 2 during 4 hours of HD was the same with the two membranes. ß-TG concentration decreased significantly during 4 hours of HD with the HeprAN membrane but remained stable with the polyflux membrane. CONCLUSION: There were no differences in clotting scores or coagulation activation with the two membranes. The decrease in ß-TG during HD with the HeprAN membrane suggests ß-TG to be an inferior marker of platelet degranulation when using a heparin-coated dialysis membrane. A possible mechanism for the decline in ß-TG concentration may be adherence of this heparin-binding protein to the heparin-coated dialysis membrane.

CXCL7 is a predictive marker of sunitinib efficacy in clear cell renal cell carcinomas.

BACKGROUND: Sunitinib is one of the first-line standard treatments for metastatic clear cell renal cell carcinoma (ccRCC) with a median time to progression shorter than 1 year. The objective is to discover predictive markers of response to adapt the treatment at diagnosis. METHODS: Prospective phase 2 multi-centre trials were conducted in ccRCC patients initiating sunitinib (54 patients) or bevacizumab (45 patients) in the first-line metastatic setting (SUVEGIL and TORAVA trials). The plasmatic level of CXCL7 at baseline was correlated with progression-free survival (PFS). RESULTS: The cut-off value of CXCL7 for PFS was 250 ng ml-1. Patients with CXCL7 plasmatic levels above the cut-off at baseline (250 ng ml-1) had a significantly longer PFS (hazard ratio 0.323 (95% confidence interval 0.147-0.707), P=0.001). These results were confirmed in a retrospective validation cohort. The levels of CXCL7 did not influence PFS of the bevacizumab-treated patients. CONCLUSIONS: CXCL7 may be considered as a predictive marker of sunitinib efficacy for ccRCC patients.

Changes in the levels of beta-thromboglobulin and inflammatory mediators during extracorporeal membrane oxygenation support.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) has been associated with platelet dysfunction, but no markers of platelet dysfunction during ECMO have been identified. METHODS: We investigated the potential uses of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) as markers of platelet activation induced by ECMO in vivo. RESULTS: 13 patients who received ECMO for acute respiratory failure were included. Generalized estimating equations were used to examine the associations between days on ECMO and the plasma levels of beta-TG and PF4 and of proinflammatory markers. Analyses were performed before ECMO (baseline) and 24, 48, 72 and 168 hours after the commencement of ECMO. The plasma levels of biomolecules were measured by ELISA and Luminex assay.Percentages of platelets varied widely without statistical significance (p = 0.17). Beta-TG levels significantly decreased over the first 72 hours (p<0.001), but PF4 levels decreased nonsignificantly (p = 0.17). Inflammatory markers, that is, plasma IL-6 (p = 0.03), IL-18 (p<0.001), and MMP-8 (p<0.01) levels stabilized during an early period of ECMO support. CONCLUSIONS: Our data suggest that ECMO use may not affect platelet activation during the first 3 days of ECMO. Plasma beta-TG levels may allow assessment of the time-dependent extent of ECMO-induced platelet dysfunction in patients with acute respiratory failure.