ABI Systems Biology Group: Research


Multiscale modelling of transepithelial fluid flows

We are developing multiscale models of the regulatory processes controlling transepithelial fluid flow in saliva secretion in the parotid gland (the largest of the salivary glands) and in lung epithelium, which regulates the depth of the fluid layer bathing the airways of the respiratory system.  

The decreased ability to produce adequate levels of saliva has been associated with numerous subjective and objective functional deficits, including the sensation of oral dryness (xerostomia), difficulty with speaking, mastication and swallowing, and an increased susceptibility to caries development and opportunistic infections (e.g., Candida albicans). Treatments are often only partially effective, frequently producing adverse side-effects and usually requiring life-long use. An important step in improving these treatments is a thorough understanding of the molecular pathways involved in saliva secretion. We are constructing a multiscale mathematical model of a prototypical salivary gland secretory unit, an acinus and attached duct, spanning from molecular to tissue level properties, in order to simulate human physiological fluid secretion and to test the role of several molecular and cellular elements in the secretion process.

The airways of the lung present an interface between the external environment and the systemic circulation. Exposure to atmospheric gases provides the source of oxygen, required for respiration, but also brings the possibility of inspiration of toxic or otherwise pernicious materials. The mucociliary transport system in the airways provides the front-line defense against inspired toxins. Without adequate hydration of the thin layer of liquid lining the airways, mucociliary transport would cease, leading to build up of mucus and impairing the clearance of any inhaled debris. Dysfunction of the mucociliary clearance system has detrimental pathological consequences, for example, the genetic disease Cystic Fibrosis. We are developing a multi-scale computational model of airway epithelial fluid transport to investigate the transport of water and heat within the airways, with which to assess current clinical metrics used to prescribe inspired air humidity for artificially ventilated patients.

Key Publications:

L. Palk, J. Sneyd, T.J. Shuttleworth, D.I. Yule, E.J. Crampin
A dynamic model of saliva secretion
Journal of Theoretical Biology 2010 (doi:10.1016/j.jtbi.2010.06.027)

N.J. Warren, E.J. Crampin, M.H. Tawhai
The role of airway epithelium in replenishment of evaporated airway surface liquid from the human conducting airways
Annals of Biomedical Engineering 2010 (doi:10.1007/s10439-010-0111-6)


N. Warren, M.H. Tawhai, E.J. Crampin
The effect of intracellular calcium oscillations on fluid secretion in airway epithelium
Journal of Theoretical Biology 265, 270-277, 2010

N.J. Warren, M.H. Tawhai, E.J. Crampin
Mathematical modelling of calcium wave propagation in airway epithelium: Evidence for regenerative ATP release
Experimental Physiology 95, 232-249, 2010

N.J. Warren, M.H. Tawhai, E.J. Crampin
A Mathematical Model of Calcium-Induced Fluid Secretion in Airway Epithelium
Journal of Theoretical Biology
259 (4), 837-849, 2009

E. Gin, E.J. Crampin, D.A. Brown, T.J. Shuttleworth, D.I. Yule, J. Sneyd
A mathematical model of fluid secretion from a parotid acinar cell
Journal of Theoretical Biology 248, 64-80, 2007

Collaborations: 

Merryn Tawhai, ABI

James Sneyd, Department of Mathematics, University of Auckland

Ted Begenisich, Jim Melvin, David Yule and Trevor Shuttleworth groups, University of Rochester

Recent Funding:


 

 Auckland Bioengineering Institute / Systems Biology Group / Research Projects