Showing papers on "Protein Z published in 2013"

Protein Z, an anticoagulant protein with expanding role in reproductive biology.

Abstract: Protein Z (PZ) is a vitamin K-dependent factor characterized by its homology to other vitamin K-dependent factors (factors VII, IX, and X, protein C and protein S), but lacks any enzymatic activity. Instead, PZ acts as a cofactor for the inhibition of factor Xa through the serpin PZ-dependent protease inhibitor (ZPI). PZ deficiency is associated with a procoagulant state, highlighted by excessive FXa secretion and thrombin production, and is linked with several thrombotic disorders, including arterial vascular and venous thromboembolic diseases. A role for the PZ-ZPI complex in the regulation of physiological pregnancy has been demonstrated, highlighted by the progressive elevation in PZ levels in the first trimester of gestation, which then steadily decline toward delivery. An association between altered plasma PZ concentrations and adverse pregnancy outcomes (recurrent miscarriage, stillbirth, preeclampsia, intrauterine growth restriction, and placental abruption) has been reported. The mechanism by which PZ deficiency leads to adverse pregnancy outcomes is not clear, but it is multifactorial. It may be attributed to the anti-PZ IgG and IgM autoantibodies, which apparently act independently of classical antiphospholipid antibodies (lupus anticoagulant, anticardiolipin, and anti-β2-glycoprotein I antibodies). PZ deficiency has also been reported to be constitutional, and a number of variants in the PROZ (PZ) gene and SERPINA10 (ZPI) gene are linked with specific adverse pregnancy complications. This review summarizes the relationship between adverse pregnancy outcomes and acquired and constitutional PZ-ZPI deficiency, in order to understand whether or not PZ deficiency could be considered as a risk factor for poor pregnancy outcomes.

Effect of thrombosis-related gene polymorphisms upon oral cancer: a regression analysis.

Abstract: It is well-known that there is an interplay between hemostasis, thrombosis and cancer. Functional DNA polymorphisms in genes encoding factors related to thrombosis have been associated with increased risk for oral squamous cell carcinoma (OSCC). The present study investigated the possible combinatory effect of 10 such polymorphisms as primary risk predictors for OSCC in a European population. Two groups including 160 patients with OSCC and 168 healthy controls of Greek and German origin were studied. The patient and control groups were comparable regarding ethnicity, age and gender. For all studied individuals, 10 genotypes of functional polymorphisms were investigated: 5,10-methylene tetrahydrofolate reductase (MTHFR) C677T, coagulation factor V (F5) Leiden, coagulation factor II (F2, also known as prothrombin) G20210A, coagulation factor XII (F12) C46T, coagulation factor XIII A1 subunit (F13A1) Val34Leu, serpine1 (SERPINE1, also known as plasminogen activator inhibitor-1) 4G/5G, protein Z (PROZ) -A13G, angiotensin I-converting enzyme (ACE) I/D, angiotensinogen (AGT) Met325Thr, and carboxypeptidase B2 (CPB2, also known as thrombin-activatable fibrinolysis inhibitor) C1040T. Multivariate logistic regression models were used in order to evaluate the relation and contribution of homozygous and heterozygous variant polymorphisms upon overall, early and advanced stages of OSCC. Five out of the studied polymorphisms, influencing the expression of SERPINE1 and ACE genes, as well as the activity of CPB2, F12 and F13 proteins, were recognized as significant predictive factors for OSCC. The 'mode of inheritance' regression model, in particular, revealed the low expression I allele of ACE to be a primary predictor in overall, early and advanced stages of oral cancer. Comparing the present findings with previous knowledge, possible interactions of these factors and their relation to the risk for OSCC development are discussed.

Contribution of protein Z and protein Z-dependent protease inhibitor in generalized Shwartzman reaction.

Abstract: OBJECTIVE Sepsis, a leading cause of mortality in critically ill patients, is closely linked to the excessive activation of coagulation and inflammation. Protein Z, a cofactor for the protein Z-dependent protease inhibitor, enhances the inhibition of coagulation factor Xa, and protein Z-dependent protease inhibitor inhibits factor XIa in a protein Z-independent fashion. The functions of protein Z and protein Z-dependent protease inhibitor in the inflammatory and coagulant responses to septic illness have not been evaluated. DESIGN For induction of generalized Shwartzman reaction, dorsal skinfold chamber-equipped mice were challenged twice with lipopolysaccharide (0.05 mg/kg on day -1 and 5 mg/kg body weight 24 hr later). Time-matched control animals received equal volumes of saline. SETTING University research laboratory. SUBJECTS, INTERVENTIONS, AND MEASUREMENTS Using intravital fluorescence microscopy in protein Z-dependent protease inhibitor deficient (ZPI) and protein Z deficient (PZ) mice, as well as their wild-type littermates (ZPI, PZ), kinetics of light/dye-induced thrombus formation and microhemodynamics were assessed in randomly chosen venules. Plasma concentrations of chemokine (C-X-C motif) ligand 1, interleukin-6, and interleukin-10 were measured. Liver and lung were harvested for quantitative analysis of leukocytic tissue infiltration and thrombus formation. MAIN RESULTS After induction of generalized Shwartzman reaction, all mice showed significant impairment of microhemodynamics, including blood flow velocity, volumetric blood flow, and functional capillary density, as well as leukocytopenia and thrombocytopenia. Thrombus formation time was markedly prolonged after induction of generalized Shwartzman reaction in all mice, except of ZPI mice, which also had a significantly higher fraction of occluded vessels in liver sections. PZ mice developed the highest concentrations of interleukin-6 and interleukin-10 in response to generalized Shwartzman reaction and showed greater leukocytic tissue infiltration than their wild-type littermates. CONCLUSIONS In this murine model of generalized Shwartzman reaction, protein Z-dependent protease inhibitor deficiency enhanced the thrombotic response to vascular injury, whereas protein Z deficiency increased inflammatory response.

The evaluation of protein Z levels of children with acute lymphoblastic leukaemia during induction therapy.

Abstract: The objective of this study was to evaluate the protein Z levels of children with acute lymphoblastic leukaemia (ALL) during induction therapy. Although several studies investigated the association between steroid and L-asparaginase (L-ASP) administration and levels of coagulation proteins such as protein C, protein S and antithrombin in children with ALL, protein Z levels have not been examined in any study yet. Peripheral blood was drawn from the study group before chemotherapy (PZ0) at diagnosis, at 12th day (PZ1), 15th day (PZ2), 18th day (PZ3) and 21st day (PZ4) of treatment wherein L-ASP treatment is given along with steroid administration according to ALL BFM-1995 chemotherapy protocol. Plasma protein Z levels were measured by enzyme immunoassay method. Mean protein Z level at PZ0 was 1.628 ± 0.485 μg/ml in the study group and 1.672 ± 0.662 μg/ml in the control group. No statistical difference was observed. In the study group, there was a slight increase in protein Z levels between the PZ0 and PZ1 periods in which only steroid therapy was administered. Statistically significant decrease was observed between protein Z levels in PZ0-PZ4, PZ1-PZ2, PZ1-PZ3, PZ1-PZ4 and PZ3-PZ4 periods. During the induction treatment, symptomatic haemorrhage or thrombosis was not followed up in any patients. We demonstrated that children with ALL have similar protein Z values to those of the control group at diagnosis. A significant decrease occurs at the end of the induction treatment with steroid and L-ASP administration. However, this deficiency does not result in development of symptomatic thrombosis or bleeding in these patients.

Structural analysis of protein Z gene variants in patients with foetal losses.

Abstract: The role of protein Z (PZ) in the etiology of human disorders is unclear. A number of PZ gene variants, sporadic or polymorphic and found exclusively in the serine protease domain, have been observed. Crystal structures of PZ in complex with the PZ-dependent inhibitor (PZI) have been recently obtained. The aim of this study was a structural investigation of the serine protease PZ domain, aiming at finding common traits across disease-linked mutations. We performed 10–20 ns molecular dynamics for each of the observed PZ mutants to investigate their structure in aqueous solution. Simulation data were processed by novel tools to analyse the residue-by-residue backbone flexibility. Results showed that sporadic mutations are associated with anomalous flexibility of residues belonging to specific regions. Among them, the most important is a loop region which is in contact with the longest helix of PZI. Other regions have been identified, which hold anomalous flexibility associated with potentially protective gene variants. In conclusion, a possible interpretation of effects associated with observed gene variants is provided. The exploration of PZ/PZI interactions seems essential in explaining these effects.