O. Andrukhova

Endothelin-1 is a useful biomarker for early detection of bronchiolitis obliterans in lung transplant recipients

OBJECTIVES Bronchiolitis obliterans (BO) is a severe complication limiting long-term survival after lung transplantation. To date, no cure exists for BO, and the mechanisms leading to BO are not well understood. Endothelin-1 (ET-1) is a potent mitogenic and profibrotic peptide produced by pulmonary vascular endothelial cells that play a role in the pathophysiology of lung allograft dysfunction. Whether ET-1 could predict BO syndrome (BOS) development is unknown. METHODS Transbronchial biopsy specimens and serum and bronchoalveolar lavage were obtained from 30 lung transplantation patients with and 30 without BOS at 3 points. The serum and bronchoalveolar lavage ET-1 concentrations were measured by enzyme-linked immunosorbent assay, and the ET-1 mRNA expression in the transbronchial biopsy specimens was examined using real-time polymerase chain reaction. RESULTS The pretransplant ET-1 serum concentrations were greater in the patients with BOS (P = .02); and ET-1 mRNA was significantly upregulated in the lung grafts of those with versus those without BOS at 3 and 12 months after transplant (P = .01). At 3 and 12 months after transplantation, the ET-1 concentrations were significantly elevated in the serum (P < .01 and P < .0001, respectively) and bronchoalveolar lavage (P < .01 and P = .02, respectively) of patients with compared with those without BOS. On logistic regression analysis, the pretransplant and 3-month post-transplant serum ET-1 level predicted for BOS (odds ratio, 1.01; 95% confidence interval, 1.004-1.025; P < .007; odds ratio, 2.9; 95% confidence interval, 1.01-8.52; P < .001). The serum ET-1 level at 12 months was diagnostic for BOS (odds ratio, 3.9; 95% confidence interval, 1.42-10.80; P = .008). CONCLUSIONS Elevated serum ET-1 concentrations were predictive of BOS, and the assessment of circulating ET-1 might be beneficial in diagnosing and monitoring BO.

Programmed Cell Death in Idiopathic Dilated Cardiomyopathy is Mediated by Suppression of the Apoptosis Inhibitor Apollon

BACKGROUND Idiopathic dilated cardiomyopathy (DCM) is characterized by ventricular wall remodeling and an increased frequency of cardiac cell apoptosis. Apollon is a 528kD cell membrane-anchored protein that inhibits apoptosis by ubiquitinylation facilitating the degradation of Smac/Diablo and caspase-9. The present study tested the hypothesis that the Apollon/Smac system may mediate programmed cell death in DCM. METHODS Apollon and caspase-9 protein expression was assessed in left ventricular biopsies of explanted failing hearts using Western blotting in 36 DCM patients undergoing cardiac transplantation and in 10 controls. Human cardiac cells were transfected with a plasmid containing the human Apollon complementary DNA or control vector and were subsequently stressed by hypoxia. Apollon, Smac/Diablo, and caspase-9 expression were then examined in cell lysates by real-time polymerase chain reaction and a transferase-mediated dUTP nick-end labeling assay was used to determine the apoptotic index. RESULTS In DCM myocardial tissue, Apollon messenger (m)RNA and protein expression was down-regulated compared with control hearts (p < 0.001 and p < 0.005, respectively) concomitant with an increase in activated caspase-9 protein levels (p < 0.001). Cell stress resulted in increased apoptosis in cardiac cells in vitro and down-regulation of Apollon mRNA expression compared with control cells (p < 0.001). Transfection increased Apollon mRNA expression in cell lysates (p < 0.001) and completely prevented hypoxia-induced apoptosis associated with reduced expression of Smac/Diablo and activated caspase-9. CONCLUSIONS These results suggest that Apollon down-regulation plays a role in programmed cell death associated with DCM. Up-regulation of Apollon might therefore represent a novel therapeutic strategy in the treatment of DCM.

Concomitant endothelin-1 overexpression in lung transplant donors and recipients predicts primary graft dysfunction.

Primary graft dysfunction (PGD) causes significant morbidity following lung transplantation (LTX). Mortality is high in PGD and therapeutic strategies are limited. To investigate whether endothelin‐1 (ET‐1) that mediates increased vascular permeability and edema formation in lung grafts can predict PGD, ET‐1 mRNA expression was examined in lung tissue biopsies of 105 donors and recipients obtained shortly before LTX. Serum ET‐1 concentration was assessed by ELISA. PGD grade was diagnosed and scored by oxygenation and radiological characteristics according to ISHLT guidelines. PGD grade 3 developed in 11% of patients. ET‐1 mRNA expression was significantly increased in both donor (p < 0.0001) and recipient (p = 0.01) developing PGD as compared to no PGD group. Pretransplant ET‐1 serum concentrations were elevated in recipients with PGD as compared to no PGD group (p < 0.0001), although serum ET‐1 was not different between donors whose grafts developed PGD grades 0–3. In regression analysis, concomitant elevated donor tissue ET‐1 and recipient serum ET‐1 predicted PGD grade 3. This study indicates that pretransplant ET‐1 mRNA overexpression in donors associated with elevated pretransplant serum ET‐1 in recipients contribute to PGD development and that their assessment might be beneficial to predict PGD and to identify recipients who could benefit from a targeted ET‐1 blockade.

DIGE Proteome Analysis Reveals Suitability of Ischemic Cardiac In Vitro Model for Studying Cellular Response to Acute Ischemia and Regeneration

Proteomic analysis of myocardial tissue from patient population is suited to yield insights into cellular and molecular mechanisms taking place in cardiovascular diseases. However, it has been limited by small sized biopsies and complicated by high variances between patients. Therefore, there is a high demand for suitable model systems with the capability to simulate ischemic and cardiotoxic effects in vitro, under defined conditions. In this context, we established an in vitro ischemia/reperfusion cardiac disease model based on the contractile HL-1 cell line. To identify pathways involved in the cellular alterations induced by ischemia and thereby defining disease-specific biomarkers and potential target structures for new drug candidates we used fluorescence 2D-difference gel electrophoresis. By comparing spot density changes in ischemic and reperfusion samples we detected several protein spots that were differentially abundant. Using MALDI-TOF/TOF-MS and ESI-MS the proteins were identified and subsequently grouped by functionality. Most prominent were changes in apoptosis signalling, cell structure and energy-metabolism. Alterations were confirmed by analysis of human biopsies from patients with ischemic cardiomyopathy. With the establishment of our in vitro disease model for ischemia injury target identification via proteomic research becomes independent from rare human material and will create new possibilities in cardiac research.

Effect of transdermal electromotive drug therapy on fibrogenic cytokine expression in Peyronie's disease.

OBJECTIVES To assess the effect of transdermal electromotive drug therapy (EMDT) on transforming growth factor-beta (TGF-beta) and basic fibroblast growth factor (bFGF) expression and their receptors in plaques in patients with Peyronies disease. METHODS Tissue was obtained from 13 patients with stable Peyronies disease who had undergone plaque excision because of penile curvature. Of the 13 patients, 7 underwent EMDT with dexamethasone, verapamil, and lidocaine as first-line therapy before plaque excision and 6 were therapy naive. TGF-beta and bFGF mRNA and protein expression and that of their receptors were measured using real-time polymerase chain reaction and Western blotting. RESULTS The mean patient age was 52.83 years. The mean interval from the end of EMDT to plaque excision was 7.6 months, with stable disease for >or=5 months. The comparison of TGF-beta mRNA expression in the plaques showed no difference between the EMDT and therapy-naive patients (P = .17). Also, TGF-beta protein expression in the plaques was not significantly different between the EMDT and therapy-naive patients (P = .443). TGF-beta receptor 1 mRNA expression in the plaques was significantly different between the EMDT and therapy-naive patients (P = .023), but no difference was found for TGF-beta receptor 2 mRNA (P = .292). The expression of bFGF mRNA (P = .0005) and bFGF protein expression (P = .034) in the plaques was significantly lower after EMDT. bFGF receptor mRNA expression (P = .619) showed no significant differences. CONCLUSIONS Patients with Peyronies had significantly lower bFGF mRNA and bFGF protein expression in the plaques after EMDT. Also, overexpression of TGF-beta protein and the TGF-beta receptor was identified in the EMDT plaques compared with the therapy-naive plaques.