Format

Send to

Choose Destination
Biophys J. 2014 Jan 7;106(1):299-309. doi: 10.1016/j.bpj.2013.11.026.

Dimensionality and size scaling of coordinated Ca(2+) dynamics in MIN6 β-cell clusters.

Author information

1
Department of Bioengineering, University of Colorado, Anschutz Medical campus, Aurora, CO.
2
Department of Biological and Chemical Engineering and the Howard Hughes Medical Institute, University of Colorado, Boulder, CO.
3
Department of Bioengineering, University of Colorado, Anschutz Medical campus, Aurora, CO; Barbara Davis Center for Childhood Diabetes, University of Colorado, Anschutz Medical Campus, Aurora, CO. Electronic address: richard.benninger@ucdenver.edu.

Abstract

Pancreatic islets of Langerhans regulate blood glucose homeostasis by the secretion of the hormone insulin. Like many neuroendocrine cells, the coupling between insulin-secreting β-cells in the islet is critical for the dynamics of hormone secretion. We have examined how this coupling architecture regulates the electrical dynamics that underlie insulin secretion by utilizing a microwell-based aggregation method to generate clusters of a β-cell line with defined sizes and dimensions. We measured the dynamics of free-calcium activity ([Ca(2+)]i) and insulin secretion and compared these measurements with a percolating network model. We observed that the coupling dimension was critical for regulating [Ca(2+)]i dynamics and insulin secretion. Three-dimensional coupling led to size-invariant suppression of [Ca(2+)]i at low glucose and robust synchronized [Ca(2+)]i oscillations at elevated glucose, whereas two-dimensional coupling showed poor suppression and less robust synchronization, with significant size-dependence. The dimension- and size-scaling of [Ca(2+)]i at high and low glucose could be accurately described with the percolating network model, using similar network connectivity. As such this could explain the fundamentally different behavior and size-scaling observed under each coupling dimension. This study highlights the dependence of proper β-cell function on the coupling architecture that will be important for developing therapeutic treatments for diabetes such as islet transplantation techniques. Furthermore, this will be vital to gain a better understanding of the general features by which cellular interactions regulate coupled multicellular systems.

PMID:
24411262
PMCID:
PMC3907241
DOI:
10.1016/j.bpj.2013.11.026
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center