S153ABSTRACTS / Journal of Molecular and Cellular Cardiology 42 (2007) S145–S161

NYHA II, 2.2-fold in NYHA III and 2.9-fold in NYHA IV.Sources of CX3CL1 production in the myocardium werefound to be cardiomyocytes and fibroblast, and we showedthat its production can be stimulated by TNFα, IL-1β andIFNγ. We also revealed that CX3CL1 had direct effects onadult cardiomyocytes, altering expression of genes involvedin leukocyte extravasation signalling and nitric oxidesignalling.

Since CX3CL1 is increased in patients with HF and affectscardiomyocyte gene expression, we suggest a role for CX3CL1in the pathogenesis of the HF syndrome.

Keywords: Heart failure; Inflammatory mediators; Fractalkine

doi:10.1016/j.yjmcc.2007.03.495

A novel Z-groove index characterizing myocardial surfacestructure and its modification in failing human heartJ. Gorelik1, L. Yang1, Y. Zhang1, M. Lab1, Y.E. Korchev1, F.

del Monte2, S.E. Harding1. 1Imperial College, London UK.2CVRC, Harvard, Boston USA

Efficiency of excitation-contraction in the adult ventricularmyocyte is enhanced by the structural organisation of themembrane. We have used a new method, the Scanning IonConductance Microscope (SICM), to investigate the changes insurface structure of ventricular myocytes from failing humanheart and to relate them to contractile effects. We comparedhypertrophic obstructive cardiomyopathy (HOCM), ischaemicheart disease (IHD), dilated cardiomyopathy (DCM) and unuseddonor (non-failing) hearts. Contractile characteristics of singlemyocytes were then measured using the IonOptix system, and inparallel imaged using the SICM which produces a 3-Dtopographical representation of the cell surface. Low numbersof t-tubules were observed in cells from failing heart with theSICM and this was confirmed using confocal microscopy afterstaining with the membrane dye di-8-ANNEPS. Additionally,the Z-groove structure of the surface was disrupted: we used anindex we have recently described to quantitate this effect andshowed that the Z-groove ratio was reduced from 0.82±0.07(mean±SEM) in non-failing (n=11) to 0.30±0.07 in failing(P<0.01), with similar effects between HOCM (n=6), IHD(n=4) and DCM (n=6). Contraction and relaxation were slow incells from failing hearts, as we have previously shown (time-to-50% relaxation, non-failing 0.11±0.01, n=6, failing0.27±0.04, n=12, P<0.01). Disruption of surface structuresis a common feature of myocytes from failing human heart andmay contribute to the alterations in excitation-contractioncoupling observed.

Keywords: Cardiomyocytes; Heart failure; Imaging

doi:10.1016/j.yjmcc.2007.03.496

NADPH oxidase is related with lipid peroxidation andredox-sensitive kinase activation in human failing heartsChiara Nediani1, Elisabetta Borchi1, Giulia d'Amati2, Alessan-

dro Mugelli1, Elisabetta Cerbai1. 1Universities of Firenze.2Roma “La Sapienza”, Italy

Increased superoxide generation by NADPH oxidase isimplicated in the pathophysiology of human heart failure. Weinvestigated a possible link between NADPH oxidase activity,lipid peroxidation and activation of 3 redox sensitive kinases(extracellular signal-regulated kinase, ERK1/2, c-jun N-term-inal kinase, JNK and p-38) in the right (RV) and left ventricle(LV) of end stage human failing hearts.

Diseased LV and RV showed a significant increase inNADPH-oxidase activity. These increases were correlated withmembrane translocation of the regulatory subunit p47phox inboth ventricles (RV: r=0.76, p<0.001; LV: r=0.79, p<0.001). Interestingly, in the diseased RV, NADPH oxidaseactivity was positively related to pulmonary arterial pressure(PAP; r=0.86, P=0.0014), suggesting that mechanical over-stretch of the RV could be a cause of the increased enzymaticactivity. Lipid peroxidation, assessed by MDA levels, was alsoenhanced and ERK and p-38, but not JNK, activated. Moreover,for all considered factors, a significant correlation was observedbetween LV and RV from the same heart (NADPH-dependentsuperoxide production: r=0.678, p<0.0055; MDA: r=0.95,p<0.0001; p-p38/p38 ratio: r=0.926, p<0.0001; p-ERK/ERKratio: r=0.913, p<0.0001).

Notwithstanding a mechanistic interpretation of the eventsdownstream to NADPH oxidase activation is prevented inhuman end-stage hearts, our results suggests a close associationamong these considered factors. Another important observationis the correlation between the left and right ventricle from thesame patient, a report of scientific and prospectively clinicalrelevance.

Keywords: Heart failure; Oxygen-derived free radicals

doi:10.1016/j.yjmcc.2007.03.497

Measurement of troponin phosphatase activities innon-failing and failing human heart muscleA. Messer, A. Jacques, S. Marston. Imperial College London,

UK

We have demonstrated that troponin isolated from failingheart confers a higher Ca2+ sensitivity and slower crossbridgeturnover rate on thin filaments compared with donor heartmuscle. We have also shown that the difference is due to verylow levels of protein kinase A (PKA) and protein kinase C(PKC) catalysed troponin I phosphorylation in failing heart.Previous investigations of phosphatases have used non-physiological substrates. We therefore investigated the troponindephosphorylation activity in human heart muscle using purehuman cardiac troponin as the substrate and whole tissue andmyofibrillar extracts of human heart as the source of the

S154 ABSTRACTS / Journal of Molecular and Cellular Cardiology 42 (2007) S145–S161

phosphatase. Using the Pro-Q diamond phosphoprotein gelstain to detect phosphorylated proteins we found that the crudephosphatase specifically dephosphorylated troponin I and nottroponin T. When measured with PKA-phosphorylated recom-binant troponin I as the substrate, heart muscle myofibrilscontained substantial phosphatase activity (up to 40,000 pmol/mg myofibril/min). Phosphatase activity was 94% inhibited by2 nM okadaic acid, 30% inhibited by 0.2 μM inhibitor-2 andCa2+-activated phosphatase activity was less than 5%. All thisindicates that protein phosphatase 2a is the predominant phos-phatase type present in human heart myofibrils. The specificactivity of the troponin I phosphatase was increased by about19.3±7.4% in failing heart muscle myofibrils compared withnon-failing heart muscle myofibrils. Therefore, enhanced phos-phatase activity may be responsible for the low levels of phos-phorylation observed in failing heart muscle.

Keywords: Heart failure; Phosphorylation; Proteins

doi:10.1016/j.yjmcc.2007.03.498

MicroRNAs in the human heart: A clue to fetal genereprogramming in heart failureT. Thum1, P. Galuppo1, S. Kneitz1, J. Fiedler1, L. Van Laake2,

C. Mummery2, G. Ertl1, J. Bauersachs1. 1Universities ofWürzburg, Germany. 2Utrecht, Netherlands

Chronic heart failure is characterized by left ventricular re-modeling and reactivation of a fetal gene program; the under-lying mechanisms are only partly understood. Here we provideevidence that cardiac microRNAs, recently discovered keyregulators of gene expression, critically determine the transcrip-tional changes observed in heart failure.

Cardiac transcriptome analyses revealed striking similaritiesbetween fetal and failing human heart tissue. Using microRNAarrays, we discovered profound alterations of microRNA ex-pression in failing hearts. These changes closely mimicked themicroRNA expression pattern observed in fetal cardiac tissue.Bioinformatic analysis demonstrated a striking concordancebetween deregulated messenger RNA expression in heart failureand the presence of microRNA binding sites in the respective 3′untranslated regions. Messenger RNAs upregulated in the fail-ing heart contained preferentially binding sites for down-regulated microRNAs and vice versa. Mechanistically, transfec-tion of cardiomyocytes with a set of fetal microRNAs inducedcellular hypertrophy and disarray as well as changes in geneexpression comparable to the failing heart.

Our data support a novel mode of regulation for the trans-criptional changes in cardiac failure. Reactivation of a fetalmicroRNA program substantially contributes to alterations ofgene expression in the failing human heart.

Keywords: Heart failure; Hypertrophy; MicroRNAs

doi:10.1016/j.yjmcc.2007.03.499

Transient enhancement of oxidant stress and collagenturnover in patients with acute decompensated congestiveheart failureYoshiyuki Kijima, Megumi Kunishige, Taku Sakai, Osamu

Akutagawa, Akiko Matsuo, Akira Nishibe, Yusuke Nakagawa,Takeshi Hata. Department of Cardiology, Higashi-Osaka CityGeneral Hospital, Osaka, Japan

Myocardial remodeling is a crucial step for progression ofheart failure. Free radical generation from failing myocardiumhas been proposed to be linked to myocardial remodeling. Theaim of this study was to evaluate urinary excretion of 8-iso-prostaglandin F2α (8-iso-PGF2α), a reliable marker for oxidantstress in vivo, and collagen turnover in patients with acuteworsening of congestive heart failure (CHF). Enrolled were 43patients with acute worsening of CHF due to various etiologies.At their admission (acute phase) and after approximately 2-week conventional treatment (chronic phase), we measured (1)immunoreactive urinary 8-iso-PGF2α, (2) serum total anti-oxidant status (TAS); and (3) serum levels of procollagen type Icarboxyterminal peptide (PIP) and carboxyterminal collagentype I telopeptide (CITP), biochemical markers for collagensynthesis and degradation, respectively. From acute phase tochronic phase these parameters were monitored: 335.1±245.4to 205.3±107.4 pg/mg creatinine for urinary 8-iso-PGF2α (P<0.0001); 0.92±0.16 to 0.98±0.13 mM for TAS (P<0.01);171.4±72.5 to 93.7±33.9 ng/ml for PIP (P<0.0001); and 7.2±3.6 to 12.6±8.4 ng/ml for CITP (P<0.0001). In conclusion,acute worsening of CHF promotes free radical generation andcollagen synthesis.

Keywords: Heart failure; Free radicals; Cardiac remodeling

doi:10.1016/j.yjmcc.2007.03.500

Remodeling of cardiac venous system in heart failureAntonio Sorgente, Cristina Conca, Angelo Auricchio, Fran-cesco Fulvio Faletra, Elena Pasotti, Giovanbattista Pedrazzini,Tiziano Moccetti.

Relational changes in patients with heart failure (HF) amongcoronary sinus (CS), left atrial and ventricular volumes andcoronary arteries have been neglected so far. The aim of thiswork was to study the spatial relationship among these struc-tures through 64 multi-slice computed tomography (64MSCT). The 64 MSCT data of individuals (age 65.1±11.5 years, 58.7% men) were evaluated. Subjects were dividedin 3 groups: 28 controls, 18 patients with coronary arterydisease but with a preserved left ventricular ejection fraction(LVEF) and 34 patients with symptomatic HF of any etiology.The following parameters were measured: CS length (CS-L),CS ostium area (CS-Oa), axial angle (AA) measured as theangle between CS and mitral annulus (MA) assessed in axialsection, mitral annulus area (MAA), left atrium volume (LAV)