Intracellular Stress Signaling Pathways Activated During Human Islet Preparation and Following Acute Cytokine Exposure

  1. Saida Abdelli1,
  2. Jeff Ansite2,
  3. Raphael Roduit1,
  4. Tiziana Borsello3,
  5. Ippei Matsumoto2,
  6. Toshiya Sawada2,
  7. Nathalie Allaman-Pillet1,
  8. Hugues Henry3,
  9. Jacques S. Beckmann1,
  10. Bernhard J. Hering2 and
  11. Christophe Bonny1
  1. 1Service of Medical Genetics, Lausanne, Switzerland
  2. 2Diabetes Institute for Immunology and Transplantation, University of Minnesota, Minneapolis, Minnesota
  3. 3University Hospital Falaises, Lausanne, Switzerland
  1. Address correspondence and reprint requests to Christophe Bonny, Service of Medical Genetics, 1011 Lausanne-CHUV, Switzerland. E-mail: christophe.bonny{at}chuv.hospvd.ch. Or Bernhard J. Hering, Diabetes Institute for ImmunologyTransplantation, University of Minnesota, 420 Delaware St. SE, Mayo Mailing Code no. 195, Minneapolis, MN 55455. E-mail: bhering{at}tumn.edu

Abstract

Pancreatic islet transplantation may successfully restore normoglycemia in type 1 diabetic patients. However, successful grafting requires transplantation of a sufficient number of islets, usually requiring two or more donors. During the isolation process and following clinical transplantation, islets are subjected to severe adverse conditions that impair survival and ultimately contribute to graft failure. Here, we have mapped the major intracellular stress-signaling pathways that may mediate human islet loss during isolation and following cytokine attack. We found that the isolation procedure potently recruits two pathways consisting of |mitogen-activated protein kinase kinase (MKK)7 → Jun NH2-terminal kinase (JNK)/p38 → c-fos| and the |nuclear factor-κB (NF-κB) → iNOS| module. Cytokines activate the |NF-κB → iNOS| and |MKK4/MKK3/6 → JNK/p38| pathways without recruitment of c-fos. Culturing the islets for 48 h after isolation allows for the activated pathways to return to background levels, with expression of MKK7 becoming undetectable. These data indicate that isolation and cytokines recruit different death pathways. Therefore, strategies might be rationally developed to avoid possible synergistic activation of these pathways in mediating islet loss during isolation and following grafting.

Footnotes

    • Accepted July 30, 2004.
    • Received February 6, 2004.
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