Emerging role of Hippo signalling in pancreatic biology: YAP re-expression and plausible link to islet cell apoptosis and replication

Biochimie. 2017 Feb:133:56-65. doi: 10.1016/j.biochi.2016.12.009. Epub 2016 Dec 18.

Abstract

Diabetes mellitus is an ailment that develops when the functional capacity of the pancreas does not meet the metabolic requirements of the whole body, either due to insulin insufficiency or resistance to insulin action. Current therapies that control glycaemia are limited by their unwanted effects or their inability to prevent the development of long-term complications. Regeneration and replacement of beta cell therapies are shaping the goals of future management of diabetes. The Hippo pathway, first discovered in Drosophila melanogaster, plays a vital role in controlling the organ size. Nuclear recruitment of YAP/TAZ (Yes-associated protein/transcriptional co-activator with PDZ-binding motif), a mammalian analogue of Yorkie protein found in Drosophila, activates cell proliferation and inhibits apoptosis. YAP was found to regulate early pancreatic development followed by downregulation during Ngn3-specific endocrine lineage maturation corresponding to their mitotic quiescence. Recent evidences have shown that optimum modulation of upstream kinases in the Hippo signalling pathway may lead to apoptosis inhibition and renewal of progenitor as well as stem cells in case of tissue or cell injury. This article reviews the evidences linking the role of various components of the Hippo pathway to pancreatic regeneration. In particular, the focus is on the beneficial role of induced YAP expression and its nuclear distribution on apoptosis and replication of adult pancreatic β islets. This approach may be of immense significance towards our fight against diabetes; thus, more insightful research is warranted in the area of Hippo signalling pathway and its involvement in pancreatic regeneration.

Keywords: Apoptosis; Hippo; Neogenesis; Pdx1; YAP/TAZ; β islet.

Publication types

  • Review

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Apoptosis / genetics
  • Cell Proliferation / genetics
  • Diabetes Mellitus / genetics*
  • Diabetes Mellitus / metabolism
  • Diabetes Mellitus / pathology
  • Hippo Signaling Pathway
  • Humans
  • Insulin / metabolism
  • Insulin Resistance / genetics
  • Islets of Langerhans / metabolism*
  • Islets of Langerhans / pathology
  • Pancreas / growth & development
  • Pancreas / metabolism*
  • Pancreas / pathology
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Protein Serine-Threonine Kinases / genetics
  • Signal Transduction
  • Transcription Factors
  • YAP-Signaling Proteins

Substances

  • Adaptor Proteins, Signal Transducing
  • Insulin
  • Phosphoproteins
  • Transcription Factors
  • YAP-Signaling Proteins
  • YAP1 protein, human
  • Protein Serine-Threonine Kinases