Scientific Report 2003-2004 - Cleveland Clinic Lerner Research ...

THE MORAVECLABORATORYRESEARCH SCHOLARNancy A. DiIulio, Ph.D.LEAD TECHNOLOGISTWendy SweetPOSTDOCTORAL FELLOWSLouise Aquila Pastir, M.S.Karin Mauer, M.D.GRADUATE STUDENTCassandra Talerico-KaplinUNDERGRADUATE STUDENTSBrad MartinKim VargasMaria YaredCOLLABORATORSMeredith Bond, Ph.D. 1Robert Fairchild, Ph.D. 2Gary Francis, M.D. 3Larry R. Jones, Ph.D. 4Evangelia Kranias, Ph.D. 5Patrick McCarthy, M.D. 6Charles McTiernan, Ph.D. 7Muthu Periasamy, Ph.D. 8Peter Reiser, Ph.D. 8Nicholas Smedira, M.D. 6Mark Sussman, Ph.D. 5Vincent Tuohy, Ph.D. 2David Van Wagoner, Ph.D. 1Jean-Pierre Yared, M.D. 2James Young, M.D. 31Dept. of Molec. Cardiol., CCF2Dept. of Immunology, CCF3Dept. of Cardiovasc. Med., CCF4Krannert Inst. of Cardiol.,Indiana Univ. Sch. of Med.,Indianapolis, IN5Univ. of Cincinnati, Cincinnati,OH6Dept. of Thoracic andCardiovascular Surgery, CCF7Univ. of Pittsburgh, Pittsburgh,PA8Dept,. of Physiology, OhioState Univ., Columbus, OHOur laboratory focuses on excitationcontractioncoupling in human heartfailure, especially the phenotypicremodeling that accompanies end-stage heartfailure, and its functional ramifications. We haveshown that significant alterations occur in thecontractile properties of cardiac muscle removedfrom failing human hearts and that these changesare linked to decreased calciumstores.We hypothesize that thesealtered calcium stores contributeto impaired contractility andtherefore decreased cardiacfunction in heart failure. In thesame failing hearts, there isdecreased expression of theproteins that control calciumcycling within the cardiacmyocyte. Significant decreaseshave been shown in the steadystatemRNA for the sarcoplasmicreticulum (SR) Ca 2+ ATPase.These changes have been observedin the failing human heart, but notin hearts having left ventricularhypertrophy with preserved ventricular function,suggesting that the decreased levels may be anend-stage phenomenon.To more directly study the effects ofalterations in these calcium regulatory proteins,we have examined the hearts of transgenic micewith alterations in these proteins. In collaborationwith Dr. Evangelia Kranias of the Universityof Cincinnati, we have measured calciumwithin the SR of mice in which the regulatoryprotein phospholamban has been knocked out.We have directly demonstrated that eliminatingphospholamban significantly increases theamount of calcium that can be stored in the SR.In collaboration with Dr. Larry Jones of theKrannert Institute, we have also shown thatoverexpression of the protein calsequestrin, acalcium-binding protein found in the SR’s lumen,increases the amount of calcium stored in theThe Department of Molecular CardiologyDecreased Expression of Proteins RegulatingCalcium Cycling Compounds Heart FailureChristine SchomischMoravec, Ph.D.SR. In an ongoing study, we are examining theeffects of overexpression of the Ca 2+ ATPase,working with Dr. Muthu Periasamy of the OhioState University.In addition to these studies, we are testingthe broader hypothesis that some of thesephenotypic changes that accompany end-stageheart failure may actually be reversible. This is animportant question, because thepotential for therapy other thanheart transplantation is directlyrelated to whether any of thestructural/functional changesoccurring in heart failure can bereversed. Using a uniquepopulation of patients, weobtain failing human heart tissuefrom surgeries implanting a leftverntricular assist device withina patient as a “bridge totransplant.” Later, when thepatient receives the new heart,after a variable number ofweeks during which the devicetakes over the mechanical loadof the circulatory system, weobtain the explanted failing heart. We are thusable to compare structural, functional, andbiochemical properties of human heart musclethat has experienced end-stage failure and asignificant period of mechanical unloading in thesame patient. Our exciting preliminary datasuggest that unloading the heart actually leads torecovery of its contractile properties, the abilityof the muscle to respond to inotropic stimulationvia the beta-adrenergic nervous system, and someof the molecular markers of heart failure,including SR Ca 2+ ATPase. Current work in thelaboratory focuses on further investigation ofthese changes, as well as determination of themechanisms that may be responsible for thisreversibility. We hope to elucidate the phenotypicchanges that are reversible and determinetheir functional significance for the heart failurepatient.Ogletree-Hughes, M.L., Stull, L.B., Sweet, W.E., Smedira, N.G., McCarthy, P.M., and C.S. Moravec (2001) Mechanicalunloading restores beta-adrenergic responsiveness and reverses receptor downregulation in the failing human heart.Circulation 104:881-886.Tan, F.L., Moravec, C.S., Li, J., Apperson-Hansen, C., McCarthy, P.M., Young, J.B., and M. Bond (2002) The geneexpression fingerprint of human heart failure. Proc. Natl. Acad. Sci. USA 99:11387-11392.Melendez, J., Welch, S., Schaefer, E., Moravec, C.S., Avraham, S., Avraham, H., and M.A. Sussman (2002) Activation ofpyk2/related focal adhesion tyrosine kinase and focal adhesion kinase in cardiac remodeling. J. Biol. Chem. 277:45203-10.Aquila-Pastir LA, DiPaola NR, Matteo RG, Smedira NG, McCarthy PM, Moravec CS. uantitation and distribution of β-tubulinin human cardiac myocytes. J. Mol. Cell. Cardiol. 34:1513-1523.Oh, H., Wang, S.C., Prahash, A., Sano, M., Moravec, C.S., et al. (2003) Telomere attrition and Chk2 activation in humanheart failure. Proc. Natl. Acad. Sci. USA 100:5378-5383.126