Non-local models for the formation of hepatocyte-stellate cell aggregates

JOURNAL OF THEORETICAL BIOLOGY

卷:267

Article

Green, J. E. F.^1,2  Waters, S. L.^2,3  Whiteley, J. P.⁴  Edelstein-Keshet, L.⁵  Shakesheff, K. M.⁶  Byrne, H. M.² 

[1] Univ Western Australia, Fac Engn Comp & Math, Sch Comp Sci & Software Engn, Computat Biol Grp, Crawley, WA 6009, Australia

[2] Univ Nottingham, Sch Math Sci, Ctr Math Med & Biol, Nottingham NG7 2RD, England

[3] Univ Oxford, Math Inst, Oxford Ctr Ind & Appl Math, Oxford OX1 3LB, England

[4] Univ Oxford, Comp Lab, Oxford OX1 3QD, England

[5] Univ British Columbia, Dept Math, Vancouver, BC V6T 1Z2, Canada

[6] Univ Nottingham, Sch Pharm, Tissue Engn Grp, Nottingham NG7 2RD, England

关键词: Cell aggregation;    Chemotaxis;    Tissue engineering;    Integro-differential equations;   

DOI  :  10.1016/j.jtbi.2010.08.013

来源: Elsevier

【 摘 要 】

Liver cell aggregates may be grown in vitro by co-culturing hepatocytes with stellate cells. This method results in more rapid aggregation than hepatocyte-only culture, and appears to enhance cell viability and the expression of markers of liver-specific functions. We consider the early stages of aggregate formation, and develop a new mathematical model to investigate two alternative hypotheses (based on evidence in the experimental literature) for the role of stellate cells in promoting aggregate formation. Under Hypothesis 1, each population produces a chemical signal which affects the other, and enhanced aggregation is due to chemotaxis. Hypothesis 2 asserts that the interaction between the two cell types is by direct physical contact: the stellates extend long cellular processes which pull the hepatocytes into the aggregates. Under both hypotheses, hepatocytes are attracted to a chemical they themselves produce, and the cells can experience repulsive forces due to overcrowding. We formulate non-local (integro-partial differential) equations to describe the densities of cells, which are coupled to reaction-diffusion equations for the chemical concentrations. The behaviour of the model under each hypothesis is studied using a combination of linear stability analysis and numerical simulations. Our results show how the initial rate of aggregation depends upon the cell seeding ratio, and how the distribution of cells within aggregates depends on the relative strengths of attraction and repulsion between the cell types. Guided by our results, we suggest experiments which could be performed to distinguish between the two hypotheses. (C) 2010 Elsevier Ltd. All rights reserved.

【 授权许可】

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