Epigenetic Erasing and Pancreatic Differentiation of Dermal Fibroblasts into Insulin-Producing Cells are Boosted by the Use of Low-Stiffness Substrate

Stem Cell Rev Rep. 2018 Jun;14(3):398-411. doi: 10.1007/s12015-017-9799-0.

Abstract

Several studies have demonstrated the possibility to revert differentiation process, reactivating hypermethylated genes and facilitating cell transition to a different lineage. Beside the epigenetic mechanisms driving cell conversion processes, growing evidences highlight the importance of mechanical forces in supporting cell plasticity and boosting differentiation. Here, we describe epigenetic erasing and conversion of dermal fibroblasts into insulin-producing cells (EpiCC), and demonstrate that the use of a low-stiffness substrate positively influences these processes. Our results show a higher expression of pluripotency genes and a significant bigger decrease of DNA methylation levels in 5-azacytidine (5-aza-CR) treated cells plated on soft matrix, compared to those cultured on plastic dishes. Furthermore, the use of low-stiffness also induces a significant increased up-regulation of ten-eleven translocation 2 (Tet2) and histone acetyltransferase 1 (Hat1) genes, and more decreased histone deacetylase enzyme1 (Hdac1) transcription levels. The soft substrate also encourages morphological changes, actin cytoskeleton re-organization, and the activation of the Hippo signaling pathway, leading to yes-associated protein (YAP) phosphorylation and its cytoplasmic translocation. Altogether, this results in increased epigenetic conversion efficiency and in EpiCC acquisition of a mono-hormonal phenotype. Our findings indicate that mechano-transduction related responsed influence cell plasticity induced by 5-aza-CR and improve fibroblast differentiation toward the pancreatic lineage.

Keywords: 5-Azacytidine; Cell plasticity; Epigenetic conversion; Hippo signaling pathway; Insulin-producing cells; Matrix elasticity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Azacitidine / pharmacology
  • Blotting, Western
  • Cell Differentiation / drug effects
  • Cell Differentiation / genetics*
  • Cell Differentiation / physiology
  • Cells, Cultured
  • DNA Methylation / drug effects
  • DNA Methylation / genetics
  • Epigenesis, Genetic / drug effects
  • Epigenesis, Genetic / genetics*
  • Fibroblasts / cytology
  • Fibroblasts / drug effects
  • Fibroblasts / metabolism*
  • Flow Cytometry
  • Histocompatibility
  • Insulin / metabolism*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Pancreas / cytology
  • Signal Transduction / drug effects
  • Signal Transduction / genetics

Substances

  • Insulin
  • Azacitidine