Our latest paper reports on computational modelling to simulate calcium release within realistic cardiomyocyte cell geometries to determine how cellular architecture can affect what you see under the microscope.
Read more in our paper:
D. Ladd, A. Tilunaite, H.L. Roderick, C. Soeller, E.J. Crampin, V. Rajagopal (2019)
Assessing cardiomyocyte excitation-contraction coupling site detection from live cell imaging using a structurally-realistic computational model of calcium release
Frontiers in Physiology 10:1263
For example, the image below indicates how the density of calcium release sites (ryanodine receptors, RyRs) within the cell will affect what you see in your confocal image.
Algorithms that detect “hot-spots” of calcium in these images as RyR sources will be affected by the density of RyRs that are present within the confocal plane, as well as ‘out of plane’ RyRs that are at a distance from the imaging plane.
This work was undertaken by David Ladd, and was lead by Vijay Rajagopal, and is the outcome of a great collaboration between Christian Soeller (@SoellerLab), Llew Roderick (@roderick_cardio) and the Crampin and Rajagopal (@cellsmb) groups.
Announcing two new papers, recently published, arising from our collaborations with the Caruso and Kent groups at UniMelb in the ARC Centre of Excellence in Convergent Bio-Nano Science and Technology (CBNS)!
M. Faria, K.F. Noi, Q. Dai, M. Björnmalm, S.T. Johnston, K. Kempe, F. Caruso, E.J. Crampin (2019)
Revisiting cell–particle association in vitro: A quantitative method to compare particle performance
Journal of Controlled Release 307, 355–367
A.C.G. Weiss, H.G. Kelly, M. Faria, Q.A. Besford, A.K. Wheatley, C.-S. Ang, E.J. Crampin, F. Caruso, S.J. Kent (2019)
Link between Low-Fouling and Stealth ‒ A Whole Blood Biomolecular Corona and Cellular Association Analysis on Nanoengineered Particles
ACS Nano 13 (5), 4980–4991
Join Prof Michael Stumpf, Prof Karin Verspoor, Dr Heejung Shim and me at the University of Melbourne and learn how to model whole cells as part of a multidisciplinary & supportive research team!
Pair correlation is used widely across biology, ecology and physics, as well as in other areas, to obtain estimates of spatial structure. Environments with obstacles or voids that inhibit and alter the motion of individuals within that environment can give rise to spurious spatial correlations. We present a corrected pair correlation function for lattice-based domains that accounts for obstacles contained within the domain, and show that this ‘obstacle pair correlation function’ is necessary for isolating the correlation associated with the behavior of individuals, rather than the structure of the environment.
Congratulations to Stuart on this paper!
S.T. Johnston, E.J. Crampin (2019)
Corrected pair correlation functions for environments with obstacles
Physical Review E 99, 032124
Our new paper “Mathematical modelling indicates that lower activity of the haemostatic system in neonates is primarily due to lower prothrombin concentration” is now published at Scientific Reports.
This is work by Ivo Siekmann which arose from a fantastic collaboration with Paul Monagle and Vera Ignjatovic from the Murdoch Childrens Research Institute.
I Siekmann, S Bjelosevic, K Landman, P Monagle, V Ignjatovic, EJ Crampin (2019)
Mathematical modelling indicates that lower activity of the haemostatic system in neonates is primarily due to lower prothrombin concentration
Scientific Reports 9 (1), 3936
Calcium signalling plays a central role in heart cells. With each heart beat, calcium is released from intracellular stores (SR) via RyR channels to trigger contraction. However, calcium signalling is also implicated in controlling the growth of heart cells, as occurs during development, in response to exercise, and in hypertrophic heart disease. This calcium signal triggers gene expression in the nucleus, and occurs via release of calcium through IP3R channels. How these two distinct calcium signals can occur at the same time is not well understood.
Here we present a mathematical model of calcium release through RyRs and IP3Rs which demonstrates that the interaction between these two calcium signalling mechanisms can increase the duty cycle of the cytosolic calcium transient (that is, increase the period during which calcium remains elevated during each cycle). This finding is consistent with recent experiments which showed that an increase in the duration of elevated cytosolic calcium leads to hypertrophy-related gene transcription.
Therefore, our work, together with the recent experimental study, suggests a plausible mechanism for IP3R-dependent hypertrophic signalling by calcium in cardiomyocytes.
This work was conducted by Hilary Hunt, in collaboration with the Soeller (Exeter) and Roderick (Leuven) labs.
H. Hunt, G. Bass, C. Soeller, L. Roderick, V. Rajagopal, E.J. Crampin
How does interaction between RyR and IP3R mediated calcium release shape the calcium transient for hypertrophic signalling in cardiomyocytes?
Our new preprint on bioRXiv describes the development of a structurally realistic 3D computational model of a cardiomyocyte which we use to simulate reaction-diffusion of calcium release from RyR clusters during the initial phase of the cardiac calcium transient. We use the model to validate a recent algorithm, CaCLEAN, adapted from radio astronomy to detect spatial locations of RyR clusters and their functional response in living cells from imaging data.
This work was conducted by Dr David Ladd, and is a collaboration with the Soeller (Exeter) and Roderick (Leuven) labs.
D. Ladd, A. Tilunaite, C. Soeller, H.L. Roderick, E.J. Crampin, V. Rajagopal
Detecting RyR clusters with CaCLEAN: influence of spatial distribution and structural heterogeneity