title: Co-culture of neural crest stem cells (NCSC) and insulin producing beta-TC6 cells results in cadherin junctions and protection against cytokine-induced beta-cell death.
abstract: OBJECTIVE
  Transplantation of pancreatic islets to Type 1 diabetes patients is hampered by inflammatory reactions at the transplantation site leading to dysfunction and death of insulin producing beta-cells. Recently we have shown that co-transplantation of neural crest stem cells (NCSCs) together with the islet cells improves transplantation outcome. The aim of the present investigation was to describe in vitro interactions between NCSCs and insulin producing beta-TC6 cells that may mediate protection against cytokine-induced beta-cell death.
  
  
  METHODS
  Beta-TC6 and NCSC cells were cultured either alone or together, and either with or without cell culture inserts. The cultures were then exposed to the pro-inflammatory cytokines IL-1β and IFN-γ for 48 hours followed by analysis of cell death rates (flow cytometry), nitrite production (Griess reagent), protein localization (immunofluorescence) and protein phosphorylation (flow cytometry).
  
  
  RESULTS
  We observed that beta-TC6 cells co-cultured with NCSCs were protected against cytokine-induced cell death, but not when separated by cell culture inserts. This occurred in parallel with (i) augmented production of nitrite from beta-TC6 cells, indicating that increased cell survival allows a sustained production of nitric oxide; (ii) NCSC-derived laminin production; (iii) decreased phospho-FAK staining in beta-TC6 cell focal adhesions, and (iv) decreased beta-TC6 cell phosphorylation of ERK(T202/Y204), FAK(Y397) and FAK(Y576). Furthermore, co-culture also resulted in cadherin and beta-catenin accumulations at the NCSC/beta-TC6 cell junctions. Finally, the gap junction inhibitor carbenoxolone did not affect cytokine-induced beta-cell death during co-culture with NCSCs.
  
  
  CONCLUSIONS
  In summary, direct contacts, but not soluble factors, promote improved beta-TC6 viability when co-cultured with NCSCs. We hypothesize that cadherin junctions between NCSC and beta-TC6 cells promote powerful signals that maintain beta-cell survival even though ERK and FAK signaling are suppressed. It may be that future strategies to improve islet transplantation outcome may benefit from attempts to increase beta-cell cadherin junctions to neighboring cells.
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden.
authors.forename: Anongnad
authors.initials: A
authors.lastname: Ngamjariyawat
authors.forename: Kyril
authors.initials: K
authors.lastname: Turpaev
authors.forename: Svitlana
authors.initials: S
authors.lastname: Vasylovska
authors.forename: Elena N
authors.initials: EN
authors.lastname: Kozlova
authors.forename: Nils
authors.initials: N
authors.lastname: Welsh
mesh_terms: D000818:Animals; D015820:Cadherins / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects; D018920:Coculture Techniques; D016207:Cytokines / Q000494:pharmacology*; D019610:Cytoprotection / Q000187:drug effects*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D022001:Focal Adhesions / Q000187:drug effects / Q000378:metabolism; D017629:Gap Junctions / Q000187:drug effects / Q000378:metabolism*; D007328:Insulin / Q000096:biosynthesis; D050417:Insulin-Secreting Cells / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D039503:Integrin alpha6 / Q000378:metabolism; D007797:Laminin / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009432:Neural Crest / Q000166:cytology*; D058953:Neural Stem Cells / Q000166:cytology*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
chemical_list: D015820:Cadherins; D016207:Cytokines; D007328:Insulin; D039503:Integrin alpha6; D007797:Laminin; D009573:Nitrites; D051176:beta Catenin; D052247:Nitric Oxide Synthase Type II; D051416:Focal Adhesion Protein-Tyrosine Kinases; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases