• Tibbits, Glen F.

    Titles

    Scientist Level 3, Cardiovascular Science, Innovations in Acute Care & Technology, CFRI
    Professor of Biomedical Physiology and Kinesiology, Simon Fraser University (SFU)
    Canada Research Chair in Molecular Cardiac Physiology
    Associate Member of Molecular Biology and Biochemistry, SFU
    Adjunct Professor of Cellular and Physiological Sciences, University of British Columbia (UBC)
    Adjunct Professor of Pathology and Laboratory Medicine, UBC
    Adjunct Professor of Pharmaceutical Sciences, UBC

    Degrees / Designations
    B.Ed., M.Sc., PhD
    Primary Area of Research
    Innovations in Acute Care & Technology
    Secondary Area(s) of Research
    Phone
    604-875-2000 ext. 6508
    Fax
    604-291-3040
    Lab Phone
    604-875-3851
    Assistant
    Helen Sheng
    Assistant Phone
    604-875-3851
    Mailing Address
    Child & Family Research Institute
    Room 2070, 950 West 28th Avenue
    Vancouver, BC V5Z 4H4
    Affiliate Websites
    Research Areas
    Myocardial excitation – contraction coupling: ontogeny and phylogeny
    Summary

    Although the neonate heart is completely responsible for delivering blood to the body, it is still immature in many respects.  This is particularly true of the cardiac contractile system and its regulatory mechanisms.  The strength of cardiac contraction is determined by the amount of calcium (Ca2+) delivered to the contractile element.  Thus the levels of Ca2+ inside each cell (or cardiomyocyte) rise and fall each beat, and peak value can vary substantially in response to physiological needs and/or hormones such as adrenaline.  How this is achieved in the neonate heart, although poorly understood, is quite different from the adult heart. This has clinical implications; for example, in children with congenital heart disease (present in 1% of live births), the heart must often be arrested during surgical correction.  However, these techniques are largely derived from our understanding of the adult heart.  We hope to improve the success rate of surgical correction, and better understand “normal” heart development and the deviations that occur in congenital heart diseases.

    Current Projects

    Molecular mechanisms of electrogenesis in the neonate heart
    CIHR funded project focusing on the molecular and cellular mechansms of junctional ectopic tachycardia (JET).  JET is an arrhythmia that occurs with relatively high frequency in neonates after open heart surgery.  The etiology of JET is poorly understood and as a consequence existing treatments are non-specific and often lack efficacy.

    Ontogeny of myocardial excitation- contraction coupling mechanisms
    CIHR funded project with the objectives of determining the molecular and cellular changes in cardiomyocytes from the earliest stages post-partum until adulthood with an eye to understanding certain congenital heart diseases. 

    Regulation of cardiac myofilament sensitivity to calcium
    Heart and Stroke Foundation funded project that addresses the structure function relationship of troponin C and its ability to bind Ca2+, a primary determinant of cardiac contractility.  The research involves making mutations of troponin C and understanding how the structural changes that result affect Ca2+ binding to the regulatory domain of the molecule.  Information from this project will be directed to the development of a novel class of Ca2+-senstizing drugs which may be used to treat heart failure.

    Selected Publications
    On C, Marshall CR, Perry SF, Le HD, Yurkov V, Omelchenko A, Hnatowich M, Hryshko LV, Tibbits GF.: Characterization of zebrafish (Danio rerio) NCX4: a novel NCX with distinct electrophysiological properties. Am J Physiol Cell Physiol. 2009 Jan;296(1):C173-81.

    Arbour L, Rezazadeh S, Eldstrom J, Weget-Simms G, Rupps R, Dyer Z, Tibbits G, Accili E, Casey B, Kmetic A, Sanatani S, Fedida D.: A KCNQ1 V205M missense mutation causes a high rate of long QT syndrome in a First Nations community of northern British Columbia: a community-based approach to understanding the impact. Genet Med. 2008 Jul;10(7):545-50.

    On C, Marshall CR, Chen N, Moyes CD, Tibbits GF.: Gene structure evolution of the Na+-Ca2+ exchanger (NCX) family. BMC Evol Biol. 2008 Apr 30;8:127.

    Liang B, Chung F, Qu Y, Pavlov D, Gillis TE, Tikunova SB, Davis JP, Tibbits GF.: Familial hypertrophic cardiomyopathy-related cardiac troponin C mutation L29Q affects Ca2+ binding and myofilament contractility. Physiol Genomics. 2008 Apr 22;33(2):257-66.

    J Huang, C van Breemen, L Hove-Madsen, and GF Tibbits.  Store-operated Ca2+ entry modulates SR Ca2+ loading in neonatal rabbit cardiac ventricular myocytes.  Circulation Research CIRCRESAHA/2005/101477 – under revision.

    TE Gillis, B Liang, F Chung, and GF Tibbits.  Increasing mammalian cardiomyocyte contractility with residues identified in trout troponin C.  Physiological Genomics. 2005 Mar 22; [Epub ahead of print] PMID: 15784699.

    CM Marshall, JA Fox, SL Butland, BFF Ouellette, FSL. Brinkman, and GF Tibbits.  Phylogeny of Na+-Ca2+ Exchanger (NCX) genes from genomic data identifies new gene duplications and a new family member in fish species.  Physiological Genomics 2005 Mar 1; [Epub ahead of print] PMID: 15741504.

    Huang J, Hove-Madsen L, Tibbits GF. Na+-Ca2+ exchange activity in neonatal rabbit ventricular myocytes.  Am J Physiol Cell Physiol. 288:C195-203, 2005. Sedarat F, Lin E, Moore ED, Tibbits GF.  Deconvolution of confocal images of dihydropyridine and ryanodine receptors in developing cardiomyocytes. J Appl Physiol. 97:1098-103, 2004. 

    TMA Blumenschein, TE Gillis, GF Tibbits and BD Sykes.  Effect of temperature on the structure of trout troponin C. Biochemistry 43:4955-63, 2004.

    TE Gillis, Tharin MA Blumenschein, BD Sykes, GF Tibbits. Trout cardiac troponin C has intermediate properties between mammalian fast skeletal and cardiac TnCs.  Biochemistry 42: 6418-26, 2003.

    S Sett, T Galanopoulos, H Kashihara, DN Talling, JG LeBlanc, GF Tibbits.  Na+/H+ exchange inhibition with HOE 642 improves recovery of the injured neonatal rabbit heart.  Can J Cardiol. 19: 1515-1519, 2003.

    Gillis TE, Moyes CD and Tibbits GF.  Sequence mutations in teleost cardiac troponin C that confer high Ca2+ affinity. Am J Physiol 284: C1176-84, 2003.

    Marshall C, Elias C, Xue XH, Le HD, Omelchenko A, Hryshko LV, Tibbits GF.  Determinants of cardiac Na+/Ca2+ exchanger temperature dependence: NH2-terminal transmembrane segments. Am J Physiol. 283:C512-20, 2002.

    Grants
    Honours & Awards
    Tier I Canada Research Chair in Molecular Cardiac Physiology
    Research Group Members

    Pauline Dan – Postdoctoral fellow

    Tiffany Qu – Lab manager / Postdoctoral fellow

    Haruyo Kashihara – Technician

    Bo Liang – Technician

    Jingbo Huang – PhD student

    Eric Lin – PhD student

    Christian Marshall – PhD student

    Perveen Biln – MSc student

    Franca Chung – MSc student

    Vivian Hung – MSc student

    Caly On – MSc student

    Helen Sheng – MSc student