ABI Systems Biology Group: Research


Virtual heart disease: signalling, metabolism and mitochondrial dysfunction in heart disease

We use mathematical modelling to examine cellular mechanisms underlying cardiac disease. 

Cardiac ischaemia arises when coronary arteries on the surface of the heart become narrow or blocked. The resulting reduction of blood flow deprives a region of the heart muscle of oxygen delivery, leading to significant changes to the normal function of individual heart cells. The condition is often fatal. The effects of ischaemia on heart muscle are complex and multifactorial, involving changes to energy metabolism, pH regulation, ionic homeostasis and electrophysiology which combine to produce the clinical symptoms of the disease. Integrative modelling provides a means of assessing the quantitative contribution of each of these components, and assessing potential therapeutic strategies. We are developing models of cardiac bioenergetics coupled to mitochondrial function, electrophysiology and excitation- contraction coupling to investigate the development of pathology, and applying these models to aspects of ischaemic heart disease including acidosis, hyperkalaemia, and mitochondrial dysfunction.

signal transduction pathway
Signal transduction pathways regulate all aspects of cardiac cell physiology: detecting, amplifying, and integrating external stimuli to trigger intracellular responses such as changes in gene expression, or to modify enzyme or ion channel activity. We are  developing models of key signalling pathways involved in regulating excitation-contraction coupling in the heart, focusing those signalling pathways thought to be responsible for mediating heart disease, in particular hypertrophy in the failing heart.


Key Publications:

J.-C. Han, A.J. Taberner, K. Tran, S. Goo, D.P. Nickerson, M.P. Nash, P.M.F. Nielsen, E.J. Crampin, D.S Loiselle
Comparison of the Gibbs and Suga Formulations of Cardiac Energetics: the Demise of 'Isoefficiency'
Journal of Applied Physiology, doi:10.1152/japplphysiol.00693.2011

M. Fink, S.A. Niederer, E.M. Cherry, F.H. Fenton, J.T. Koivumaki, G. Seemann, R. Thul, H. Zhang, F.B. Sachse*, D.A. Beard*, E.J. Crampin*, N.P. Smith*
Cardiac cell modelling: Observations from the heart of the cardiac physiome project
Progress in Biophysics & Molecular Biology 104 (1-3), 2-21, 2011

D. Loiselle D., K. Tran, E.J. Crampin, N. Curtin.
Why has Reversal of the Actin-Myosin Cross-Bridge Cycle Not Been Observed Experimentally?
Journal of Applied Physiology 108, 1465-1471, 2010

K. Tran, N.P. Smith, D.S. Loiselle, E.J. Crampin
A metabolite-sensitive, thermodynamically-constrained model of cardiac cross-bridge cycling: Implications for force development during ischemia
Biophysical Journal 98, 267-276, 2010

K. Tran, N.P. Smith, D.S. Loiselle, E.J. Crampin
A thermodynamic model of the cardiac sarcoplasmic/endoplasmic Ca2+ (SERCA) pump
Biophysical Journal 96 (5), 2029-2042, 2009

M.T. Cooling, P.J. Hunter, E.J. Crampin
Sensitivity of NFAT cycling to cytosolic calcium: Implications for hypertrophic signalling in cardiac myocytes
Biophysical Journal 96 (6), 2095-2104, 2009

J. Terkildsen, E.J. Crampin, N.P. Smith
The balance between inactivation and activation of the Na+-K+ pump underlies the triphasic accumulation of extracellular K+ ions during myocardial ischemia
American Journal of Physiology, Heart and Circulatory Physiology 293, H3036-H3045, 2007

M. Cooling, P.J. Hunter, E.J. Crampin
Modelling hypertrophic IP3 transients in the cardiac myocyte
Biophysical Journal 93 3421-3433, 2007


E.J. Crampin, N.P. Smith
A dynamic model of excitation-contraction coupling during acidosis in cardiac ventricular myocytes
Biophysical Journal 90, 3074-3090, 2006

N.P. Smith, E.J. Crampin
Development of models of active ion transport for whole-cell modelling: Cardiac sodium-potassium pump as a case study
Progress in Biophysics & Molecular Biology 85 (2-3), 387-405, 2004

E.J. Crampin, M. Halstead, P. Hunter, P. Nielsen, D. Noble, N. Smith, M. Tawhai
Computational Physiology and the Physiome Project
Experimental Physiology 89 (1), 1-26, 2004

International Collaborations: 

Dan Beard (Medical College Wisconsin), Nic Smith (University of Oxford)

Recent Funding:

 

 Auckland Bioengineering Institute / Systems Biology Group / Research Projects