Plasma soluble fms-like tyrosine kinase-1, placental growth factor, and vascular endothelial growth factor system gene variants as predictors of survival in heart failure.

AIMS: Soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF), components of the vascular endothelial growth factor (VEGF) system, play key roles in angiogenesis. Reports of elevated plasma levels of sFlt-1 and PlGF in coronary heart disease and heart failure (HF) led us to investigate their utility, and VEGF system gene single nucleotide polymorphisms (SNPs), as prognostic biomarkers in HF. METHODS AND RESULTS: ELISA assays for sFlt-1, PlGF and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were performed on baseline plasma samples from the PEOPLE cohort (n = 890), a study of outcomes among patients after an episode of acute decompensated HF. Eight SNPs potentially associated with sFlt-1 or PlGF levels were genotyped. sFlt-1 and PlGF were assayed in 201 subjects from the Canterbury Healthy Volunteers Study (CHVS) matched to PEOPLE participants. All-cause death was the major endpoint for clinical outcome considered. In PEOPLE participants, mean plasma levels for both sFlt-1 (125 ± 2.01 pg/ml) and PlGF (17.5 ± 0.21 pg/ml) were higher (both p < 0.044) than in the CHVS cohort (81.2 ± 1.31 pg/ml and 15.5 ± 0.32 pg/ml, respectively). sFlt-1 was higher in HF with reduced ejection fraction compared to HF with preserved ejection fraction (p = 0.005). The PGF gene SNP rs2268616 was univariately associated with death (p = 0.016), and was also associated with PlGF levels, as was rs2268614 genotype. Cox proportional hazards modelling (n = 695, 246 deaths) showed plasma sFlt-1, but not PlGF, predicted survival (hazard ratio 6.44, 95% confidence interval 2.57-16.1; p < 0.001) in PEOPLE, independent of age, NT-proBNP, ischaemic aetiology, diabetic status and beta-blocker therapy. CONCLUSIONS: Plasma sFlt-1 concentrations have potential as an independent predictor of survival and may be complementary to established prognostic biomarkers in HF.

Vascular endothelial growth factor-A promoter polymorphisms, circulating VEGF-A and survival in acute coronary syndromes.

BACKGROUND: Development of a competent collateral circulation in established coronary artery disease is cardio-protective. The vascular endothelial growth factor (VEGF) system plays a key role in this process. We investigated the prognostic performance of circulating VEGF-A and three genetic variants in the VEGFA gene in a clinical coronary cohort. METHODS AND RESULTS: The Coronary Disease Cohort Study (CDCS) recruited 2,140 patients, with a diagnosis of acute coronary syndrome (ACS), after admission to Christchurch or Auckland City Hospitals between July 2002 and January 2009. We present data for 1927 patients from the cohort genotyped for three SNPs in the VEGF-A gene, rs699947 (C-2578A), rs2010963 (C405G) and rs3025039 (C936T). Plasma VEGF-A concentrations were assayed in a subgroup (n = 550) of CDCS patients (geometric mean 36.6 [34.7-38.5] pg/ml). VEGF-A levels correlated with patient heart rate at baseline (p = 0.034). None of rs699947, rs3025039, nor rs2010963 genotypes were significantly associated with VEGF-A levels, but rs3025039 genotype was positively associated with collateral vessels perfusion according to the Rentrop classification (p = 0.01) and baseline natriuretic peptide levels (p<0.05). Survival in the CDCS cohort was independently associated with baseline VEGF-A levels and (in males) with rs699947 genotype. CONCLUSIONS: This study is strongly suggestive that VEGF-A levels have value as a prognostic biomarker in coronary heart disease patients and SNPs in VEGF-A deserve further investigation as prognostic markers and indicators of angiogenic potential influencing the formation of collateral circulation.

Expression of the serpin centerin defines a germinal center phenotype in B-cell lymphomas.

Centerin (SERPINA9/GCET1) is a protease inhibitor with expression restricted to germinal center B cells and lymphoid malignancies with germinal center B-cell maturation. Expression of the centerin gene transcript, along with bcl-6 and GCET2/HGAL, constitutes a molecular signature associated with a good prognosis in diffuse large B-cell lymphomas. A monoclonal antibody to centerin was generated and used for Western blotting, immunohistochemistry, and immunofluorescence. Centerin expression was demonstrated in Burkitt lymphoma Raji cells. An immunohistochemical survey of normal tissues showed centerin expression in germinal center B cells in lymphoid follicles in tonsil, lymph node, and lymphoid tissue in the gastrointestinal tract. Centerin was strongly expressed in most follicular lymphomas. In addition, 14 (47%) of 30 diffuse large B-cell lymphomas were positive for centerin, which correlated most closely with CD10 expression. Immunohistochemical expression of centerin further defines the germinal center cell origin of a subgroup of lymphomas.

Molecular characterization of centerin, a germinal centre cell serpin.

Centerin [SERPINA9/GCET1 (germinal centre B-cell-expressed transcript 1)] is a serpin (serine protease inhibitor) whose expression is restricted to germinal centre B-cells and lymphoid malignancies with germinal centre B-cell maturation. Expression of centerin, together with bcl-6 and GCET2, constitutes a germinal centre B-cell signature, which is associated with a good prognosis in diffuse large B-cell lymphomas, but the molecular basis for this remains to be elucidated. We report here the cloning, expression and molecular characterization of bacterial recombinant centerin. Biophysical studies demonstrated that centerin was able to undergo the 'stressed to relaxed' conformational change which is an absolute requirement for protease inhibitory activity. Kinetic analysis showed that centerin rapidly inhibited the serine protease trypsin (k(a)=1.9x10(5) M(-1) x s(-1)) and also demonstrated measurable inhibition of thrombin (k(a)=1.17x10(3) M(-1) x s(-1)) and plasmin (k(a)=1.92x10(3) M(-1) x s(-1)). Centerin also bound DNA and unfractionated heparin, although there was no functionally significant impact on the rate of inhibition. These results suggest that centerin is likely to function in vivo in the germinal centre as an efficient inhibitor of a trypsin-like protease.