Acute Ischemia Induced by High-Density Culture Increases Cytokine Expression and Diminishes the Function and Viability of Highly Purified Human Islets of Langerhans

Transplantation. 2017 Nov;101(11):2705-2712. doi: 10.1097/TP.0000000000001714.


Background: Encapsulation devices have the potential to enable cell-based insulin replacement therapies (such as human islet or stem cell-derived β cell transplantation) without immunosuppression. However, reasonably sized encapsulation devices promote ischemia due to high β cell densities creating prohibitively large diffusional distances for nutrients. It is hypothesized that even acute ischemic exposure will compromise the therapeutic potential of cell-based insulin replacement. In this study, the acute effects of high-density ischemia were investigated in human islets to develop a detailed profile of early ischemia induced changes and targets for intervention.

Methods: Human islets were exposed in a pairwise model simulating high-density encapsulation to normoxic or ischemic culture for 12 hours, after which viability and function were measured. RNA sequencing was conducted to assess transcriptome-wide changes in gene expression.

Results: Islet viability after acute ischemic exposure was reduced compared to normoxic culture conditions (P < 0.01). Insulin secretion was also diminished, with ischemic β cells losing their insulin secretory response to stimulatory glucose levels (P < 0.01). RNA sequencing revealed 657 differentially expressed genes following ischemia, with many that are associated with increased inflammatory and hypoxia-response signaling and decreased nutrient transport and metabolism.

Conclusions: In order for cell-based insulin replacement to be applied as a treatment for type 1 diabetes, oxygen and nutrient delivery to β cells will need to be maintained. We demonstrate that even brief ischemic exposure such as would be experienced in encapsulation devices damages islet viability and β cell function and leads to increased inflammatory signaling.

MeSH terms

  • Adult
  • Cell Hypoxia
  • Cell Survival
  • Cytokines / genetics
  • Cytokines / metabolism*
  • Female
  • Gene Expression Profiling
  • Humans
  • Inflammation Mediators / metabolism*
  • Insulin / metabolism
  • Insulin Secretion
  • Insulin-Secreting Cells / metabolism*
  • Insulin-Secreting Cells / pathology
  • Islets of Langerhans / metabolism*
  • Islets of Langerhans / pathology
  • Male
  • Middle Aged
  • Signal Transduction
  • Time Factors
  • Tissue Culture Techniques*
  • Tissue Survival
  • Up-Regulation


  • Cytokines
  • Inflammation Mediators
  • Insulin