Redifferentiation of expanded human islet β cells by inhibition of ARX

Sci Rep. 2016 Feb 9;6:20698. doi: 10.1038/srep20698.

Abstract

Ex-vivo expansion of adult human islet β cells has been evaluated for generation of abundant insulin-producing cells for transplantation; however, lineage-tracing has demonstrated that this process results in β-cell dedifferentiation. Redifferentiation of β-cell-derived (BCD) cells can be achieved using a combination of soluble factors termed Redifferentiation Cocktail (RC); however, this treatment leads to redifferentiation of only a fraction of BCD cells. This study aimed at improving redifferentiation efficiency by affecting the balance of islet progenitor-cell transcription factors activated by RC treatment. Specifically, RC treatment induces the transcription factors PAX4 and ARX, which play key roles in directing pancreas endocrine progenitor cells into the β/δ or α/PP developmental pathways, respectively. Misactivation of ARX in RC-treated BCD cells may inhibit their redifferentiation into β cells. Blocking ARX expression by shRNA elevated insulin mRNA levels 12.8-fold, and more than doubled the number of insulin-positive BCD cells. ARX inhibition in expanded α-cell-derived cells treated with RC did not cause their transdifferentiation into insulin-producing cells. The combination of RC and ARX shRNA treatment may facilitate the generation of abundant insulin-producing cells for transplantation into patients with type 1 diabetes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cell Dedifferentiation*
  • Cell Proliferation*
  • Cells, Cultured
  • Cellular Reprogramming Techniques / methods*
  • Homeodomain Proteins / antagonists & inhibitors*
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Humans
  • Insulin-Secreting Cells / cytology
  • Insulin-Secreting Cells / metabolism*
  • Paired Box Transcription Factors / genetics
  • Paired Box Transcription Factors / metabolism
  • Transcription Factors / antagonists & inhibitors*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • ARX protein, human
  • Homeodomain Proteins
  • PAX4 protein, human
  • Paired Box Transcription Factors
  • Transcription Factors