AIMSPatients with heart failure (HF) have elevated values of the pro-inflammatory protein CD40L but the underlying mechanism is unclear. This study was performed to evaluate the interplay between tumour necrosis factor alpha (TNFalpha) and CD40L in HF.METHODS AND RESULTSIn patients with HF (n=86) and healthy subjects (HS, n=43), plasma levels of soluble CD40L (sCD40L), TNFalpha, soluble receptors of TNFalpha such as soluble TNF receptors I and II (sTNFR1 and sTNFR2), and 8OH-dG, a marker of oxidative stress, were determined. Also, an in vitro study was performed by determining platelet CD40L regulation upon platelet stimulation with TNFalpha. Compared with HS, HF patients had higher plasma values of sCD40L, TNFalpha, sTNFR1 and sTNFR2, and higher platelet expression of TNFR1 and TNFR2 with a progressive increase from NYHA I to NYHA IV classification. sCD40L significantly correlated with TNFalpha, sTNFR1, and sTNFR2; plasma levels of TNFalpha significantly correlated with sCD40L. Incubation of platelets from HF patients with a TNFalpha receptor inhibitor significantly decreased platelet CD40L expression. The in vitro study demonstrated that TNFalpha significantly increased CD40L expression, an effect weakly influenced by aspirin but significantly reduced by AACOCF3, an inhibitor of PLA(2), apocynin, an inhibitor of NADPH oxidase, or staurosporine, an inhibitor of PKC.CONCLUSIONThe study shows that in HF patients, platelet CD40L is upregulated by TNFalpha via a cyclooxygenase-1-independent, arachidonic acid-mediated oxidative stress mechanism.

Arterial dysfunction is a hallmark of early atherosclerosis; however, its behavior in patients with metabolic syndrome (MS) is still unclear. We investigated the role of oxidative stress on ischemia-induced flow-mediated dilatation (FMD) in patients with MS. FMD and oxidative stress, as assessed by serum levels of 8-hydroxy-2-deoxy-2-deoxyguanosine (8-OHdG), were studied in 18 MS and 30 control subjects. Thereafter, in the 18 MS patients, FMD was assessed after iv infusion of 1 g vitamin C or placebo in a randomized, double-blind, crossover design; serial blood samples were taken in peripheral circulation before and after FMD to analyze 8-OHdG. Compared to controls, MS patients had higher 8-OHdG (p < 0.001) and lower FMD (p < 0.001); 8-OHdG and FMD were inversely correlated (R=-0.74; p < 0.01). In MS patients, placebo administration did not change FMD, whereas vitamin C significantly enhanced it (p < 0.001). After placebo, ischemia-induced FMD was associated with a significant increase in 8-OHdG (p < 0.001), an effect that was counteracted by vitamin C. Vitamin C infusion was associated with an inverse correlation between the changes in FMD and oxidative stress (R=-0.67; p < 0.01). The present study shows that arterial dilatation is impaired and that enhanced oxidative stress may play a key role in patients with MS. (c) 2007 Elsevier Inc. All rights reserved.

Molecular cloning of the translocations t(12;22)(p13;q12) and t(12;17)(p13;q11) in acute leukaemia showed that either EWSR1 or its homologue TAF15 are fused to the transcription factor CIZ. EWSR1 and TAF15 belong to the TET family ( T LS/FUS, E WSR1 and T AF15) of proteins. TET fusions have been identified in both solid tumours and acute myeloid leukaemia. The novel 12p translocations directly implicated TET fusions in acute lymphoblastic leukaemia as well, and demonstrated the involvement of CIZ in haematopoietic malignancies. In addition, a new fusion E2A‐CIZ was recently cloned as a result of a t(12;19)(p13;p13) in a patient with acute lymphoblastic leukaemia. NIH3T3 cells stably expressing TET‐CIZ fusions display a transformed phenotype in a focus formation assay. We show here that E2A‐CIZ also transforms 3T3 fibroblasts, suggesting that the addition of a transactivation domain to the CIZ protein is involved in this phenotype. An artificial VP16‐CIZ construct reveals similar transforming properties, supporting this. We have then analysed the domains within TAF15‐CIZ that are necessary for 3T3 fibroblast transformation. Deletion of the zinc fingers of CIZ resulted in loss of both DNA‐binding and transforming properties of TAF15‐CIZ, whereas deletion of the other functional domains of CIZ had no effect. Fusion of a transactivation domain to CIZ is suggestive for a transactivating function in transformation. Luciferase experiments indeed showed that E2A‐CIZ as well as VP16‐CIZ transactivates the MMP7 promoter. Taken together, our results reported here suggest that transformation of 3T3 fibroblasts by CIZ fusions is dependent on DNA‐binding and might involve transactivation of CIZ target genes. © 2004 Wiley‐Liss, Inc.

Fusions of the TET-proteins (TLS/FUS, EWSR1, and TAF15/RBP56) to different transcription factors are involved in various malignancies including Ewing's sarcoma, primitive neuroectodermal tumors, and acute myeloid leukemia. These are thought to arise through transcriptional deregulation, with the transcription factor defining the tumor phenotype. We show that, as result of a t(12;17)(p13;q11) or its variant t(12;22)(p13;q12), the transcription factor gene CIZ/NMP4 is recurrently involved in acute leukemia through fusion with either EWSR1 or TAF15. The fusions possess transforming properties in NIH3T3 cells but do not affect the expression of CIZ target genes, suggesting a contribution to oncogenesis that is independent of the transactivating properties of the fusion protein. These results also extend the involvement of TET-protein fusions to acute lymphoblastic leukemia and suggest a role for CIZ/NMP4 in lymphoid and myeloid development.