Effect of the Extracellular Matrix on Pancreatic Endocrine Cell Function and its Biocompatibility in Dogs

Abstract

The effect of the synthetic extracellular matrix (ECM) in a diffusion chamber for a bioartificial endocrine pancreas (Bio-AEP) on pancreatic endocrine cells in vitro and its biocompatibility in dogs were investigated. Two different types of ECM were used: type I collagen treated with low antigen (type I LA), and reconstituted basement membrane matrix (Matrigel) derived from Englbreth-Holm-Swarm (EHS) mouse sarcoma. Matrigel contains growth and differentiation factors and cell adhesion molecules such as laminin, heparan sulfate proteoglycan, and entactin. Purified porcine pancreatic endocrine (PE) cells were suspended in type I LA or Matrigel and then placed into a 12-well culture plate (4 × 10 7 cells/ml ؒ gel/well). The insulin accumulation from PE cells in Matrigel was significantly greater than that in type I LA (9.3 ± 3.6 mU/well vs. 2.3 ± 1.3 mU/well). When Bio-AEP with Matrigel and PE cells was implanted into the abdominal cavity of a pancreatectomized diabetic dog, the exogenous insulin requirement for maintaining normoglycemia was reduced for the first 4 weeks. However, after 6 weeks of implantation, fasting blood glucose levels suddenly increased. Laparotomy revealed encapsulated Bio-AEP with thick fibrous tissue. Following removal of the Bio-AEP from the abdominal cavity, another Bio-AEP containing type I LA and PE cells was implanted into the same dog. The exogenous insulin requirement was gradually decreased to almost half that of preimplantation levels. Bio-AEPs containing type I LA or Matrigel, but not PE cells, were implanted into the abdominal cavities of four healthy dogs. After 4 weeks of implantation, the Bio-AEP with Matrigel was encapsulated with fibrous tissue similar to that in the diabetic dog, but the Bio-AEP with type I LA was not.These results indicate that Matrigel may be incompatible with dogs and that the type I LA is more suitable for Bio-AEP.

Co-localization of nestin and insulin and expression of islet cell markers in long-term human pancreatic nestin-positive cell cultures

“…The evidence presented here, showing an increased insulin accumulation in the presence of Matrigel, is in good agreement with previous data showing the effect of this product on the maintenance of normal cell function (Perfetti et al 1996, Edamura et al 2001, Oberg-Welsh 2001. However, in contrast with the transdifferentiation/ differentiation effect that has been described for islet (Kerr-Conte et al 1996), acinar (Arias & Bendayan 1993) and ductal cells (Bonner-Weir et al 2000), our attempt to promote differentiation of nestin-positive cells by subculturing onto a Matrigel-coated surface only induced cell migration and formation of islet-like clusters after 24 h, with unaltered insulin and nestin expression levels.…”

Xenotransplantation of Porcine Pancreatic Endocrine Cells to Total Pancreatectomized Dogs

“…These findings might be associated with some type of immune response to the Bio-AEP. In our previous investigation on the biocompatibility of the Bio-AEP without PE-cells in normal dogs, immunological reactions to the silicon ring, nuclepore membrane, and the ECM with type-I collagen treated to reduce the antigenicity were not detected for at least 3 months after implantation [4,5]. The present findings suggested that PE-cells might induce some type of immune response in the recipient, leading to fibrous tissue encapsulation.…”

Extracellular matrix proteins involved in pseudoislets formation

“…For example, fibronectin has been shown to inhibit apoptosis 23 and laminin, to increase long term culture preservation. 24 The importance of cell matrix interactions for optimal regulated insulin secretion is supported by several studies on β-cells cultured on various crude matrices or their purified extracts. [25][26][27] Besides, β-cells cultured on 804G matrix have been shown to increase the basal and stimulated insulin release.…”