PED/PEA-15 inhibits hydrogen peroxide-induced apoptosis in Ins-1E pancreatic beta-cells via PLD-1

PLoS One. 2014 Dec 9;9(12):e113655. doi: 10.1371/journal.pone.0113655. eCollection 2014.

Abstract

The small scaffold protein PED/PEA-15 is involved in several different physiologic and pathologic processes, such as cell proliferation and survival, diabetes and cancer. PED/PEA-15 exerts an anti-apoptotic function due to its ability to interfere with both extrinsic and intrinsic apoptotic pathways in different cell types. Recent evidence shows that mice overexpressing PED/PEA-15 present larger pancreatic islets and increased beta-cells mass. In the present work we investigated PED/PEA-15 role in hydrogen peroxide-induced apoptosis in Ins-1E beta-cells. In pancreatic islets isolated from Tg(PED/PEA-15) mice hydrogen peroxide-induced DNA fragmentation was lower compared to WT islets. TUNEL analysis showed that PED/PEA-15 overexpression increases the viability of Ins-1E beta-cells and enhances their resistance to apoptosis induced by hydrogen peroxide exposure. The activity of caspase-3 and the cleavage of PARP-1 were markedly reduced in Ins-1E cells overexpressing PED/PEA-15 (Ins-1E(PED/PEA-15)). In parallel, we observed a decrease of the mRNA levels of pro-apoptotic genes Bcl-xS and Bad. In contrast, the expression of the anti-apoptotic gene Bcl-xL was enhanced. Accordingly, DNA fragmentation was higher in control cells compared to Ins-1E(PED/PEA-15) cells. Interestingly, the preincubation with propranolol, an inhibitor of the pathway of PLD-1, a known interactor of PED/PEA-15, responsible for its deleterious effects on glucose tolerance, abolishes the antiapoptotic effects of PED/PEA-15 overexpression in Ins-1E beta-cells. The same results have been obtained by inhibiting PED/PEA-15 interaction with PLD-1 in Ins-1E(PED/PEA-15). These results show that PED/PEA-15 overexpression is sufficient to block hydrogen peroxide-induced apoptosis in Ins-1E cells through a PLD-1 mediated mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Apoptosis Regulatory Proteins
  • Female
  • HeLa Cells
  • Humans
  • Hydrogen Peroxide / pharmacology*
  • Insulin-Secreting Cells / cytology*
  • Insulin-Secreting Cells / drug effects*
  • Insulin-Secreting Cells / metabolism
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Male
  • Mice
  • Phospholipase D / metabolism*
  • Phosphoproteins / metabolism*
  • Rats

Substances

  • Apoptosis Regulatory Proteins
  • Intracellular Signaling Peptides and Proteins
  • PEA15 protein, human
  • Phosphoproteins
  • Hydrogen Peroxide
  • Phospholipase D
  • phospholipase D1

Grants and funding

This work has been supported by: the European Foundation for the Study of Diabetes (EFSD), the Associazione Italiana per la Ricerca sul cancro (AIRC), the Ministero dell'Università e della Ricerca Scientifica (grants PRIN and FIRB-MERIT, and PON 01_02460) and the Società Italiana di Diabetologia (SID-FO.DI.RI). This work was also supported by the P.O.R. Campania FSE 2007–2013, Project CREMe. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.