In vitro generation of peri-islet basement membrane-like structures

Biomaterials. 2021 Jun;273:120808. doi: 10.1016/j.biomaterials.2021.120808. Epub 2021 Apr 13.

Abstract

The peri-islet extracellular matrix (ECM) is a key component of the microenvironmental niche surrounding pancreatic islets of Langerhans. The cell anchorage and signaling provided by the peri-islet ECM is critical for optimum beta cell glucose responsiveness, but islets lose this important native ECM when isolated for transplantation or in vitro studies. Here, we established a method to construct a peri-islet ECM on the surfaces of isolated rat and human islets by the co-assembly from solution of laminin, nidogen and collagen IV proteins. Successful deposition of contiguous peri-islet ECM networks was confirmed by immunofluorescence, western blot, and transmission electron microscopy. The ECM coatings were disrupted when assembly occurred in Ca2+/Mg2+-free conditions. As laminin network polymerization is divalent cation dependent, our data are consistent with receptor-driven ordered ECM network formation rather than passive protein adsorption. To further illustrate the utility of ECM coatings, we employed stem cell derived beta-like cell clusters (sBCs) as a renewable source of functional beta cells for cell replacement therapy. We observe that sBC pseudo-islets lack an endogenous peri-islet ECM, but successfully applied our approach to construct a de novo ECM coating on the surfaces of sBCs.

Keywords: Basement membrane; Extracellular matrix; Laminin-nidogen-collagen IV; Pancreatic islet; Stem cell-derived beta cell; Type 1 diabetes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basement Membrane
  • Collagen Type IV
  • Extracellular Matrix
  • Islets of Langerhans Transplantation*
  • Islets of Langerhans*
  • Laminin
  • Rats

Substances

  • Collagen Type IV
  • Laminin