title: Improved human islet preparations using glucocorticoid and exendin-4.
abstract: OBJECTIVE
  The effects of glucocorticoid during culture on human islet cells have been controversial. Exendin-4 (EX) enhances the insulin secretion and significantly improves clinical outcomes in islet cell transplantation. In this study, we examined the effects of glucocorticoids and EX on human islet cells during pretransplant culture.
  
  
  METHODS
  Methylprednisolone (MP) and/or EX were added to the standard culture medium for clinical islet cell transplantation. Islets were cultured for 24 hours with 3 different conditions (control, no additives; MP alone; and MP + EX). β-Cell fractional viability, cellular composition, multiple cytokine/chemokine production, multiple phosphorylation proteins, and glucose-induced insulin secretion were evaluated.
  
  
  RESULTS
  Viable β-cell survival in MP and MP + EX group was significantly higher than in the control group. Exendin-4 prevented MP-induced reduction of insulin secretion. Methylprednisolone supplementation to the culture medium decreased cytokine and chemokine production. Moreover, extracellular signal-regulated kinase 1/2 phosphorylation was significantly increased by MP and MP + EX.
  
  
  CONCLUSIONS
  Glucocorticoid supplementation into culture media significantly decreased the cytokine/chemokine production and increased the extracellular signal-regulated kinase 1/2 phosphorylation, resulting in the improvement of human β-cell survival. In addition, EX maintained the insulin secretion suppressed by MP. The supplementation of MP and EX together could be a useful strategy to create suitable human islets for transplantation.
authors.affiliation: From the *Cell Transplant Center, Diabetes Research Institute, †DeWitt Family Department of Surgery, ‡Jackson Memorial Hospital Transplant Institute, §Department of Microbiology and Immunology, and ∥Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, FL; and ¶Department of Surgery and Medicine, University of California Irvine, Orange, CA.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Miki
authors.forename: Camillo
authors.initials: C
authors.lastname: Ricordi
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Yasunaru
authors.initials: Y
authors.lastname: Sakuma
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Misawa
authors.forename: Atsuyoshi
authors.initials: A
authors.lastname: Mita
authors.forename: Luca
authors.initials: L
authors.lastname: Inverardi
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Alejandro
authors.forename: Hirohito
authors.initials: H
authors.lastname: Ichii
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods*; D002470:Cell Survival; D018925:Chemokines / Q000378:metabolism; D003470:Culture Media / Q000494:pharmacology*; D016207:Cytokines / Q000378:metabolism; D000077270:Exenatide; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D018836:Inflammation Mediators; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008775:Methylprednisolone / Q000494:pharmacology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D010455:Peptides / Q000494:pharmacology; D010750:Phosphoproteins / Q000032:analysis; D010766:Phosphorylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D014688:Venoms / Q000494:pharmacology
chemical_list: D018925:Chemokines; D003470:Culture Media; D016207:Cytokines; D018836:Inflammation Mediators; D007328:Insulin; D010455:Peptides; D010750:Phosphoproteins; D014688:Venoms; D000077270:Exenatide; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D005947:Glucose; D008775:Methylprednisolone