title: Perfluorocarbon emulsions prevent hypoxia of pancreatic β-cells.
abstract: As oxygen carriers, perfluorocarbon emulsions might be useful to decrease hypoxia of pancreatic islets before transplantation. However, their hydrophobicity prevents their homogenisation in culture medium. To increase the surface of contact between islets and Perfluorooctyl bromide  (PFOB), and consequently oxygen delivery, we tested effect of a PFOB emulsion in culture medium on β-cell lines and rat pancreatic islets. RINm5F β-cell line or pancreatic rat islets were incubated for 3 days in the presence of PFOB emulsion in media (3.5% w/v). Preoxygenation of  the medium was performed before culture. Cell viability was assessed by apoptotic markers (Bax and Bcl-2) and by staining (fluoresceine diacetate and propidium iodide). β-Cell functionality was determined by insulin release during a glucose stimulation test and. Hypoxia markers, HIF-1α  and VEGF, were studied at days 1 and 3 using RT-PCR, Western blotting, and ELISA. PFOB emulsions preserved viability and functionality of RINm5F cells with a decrease of HIF-1α and VEGF expression. Islets viability was preserved during 3 days of culture. Secretion of VEGF was higher  in untreated control (0.09 ± 0.041 μg VEGF/mg total protein) than in PFOB emulsion incubated islets (0.02 ± 0.19 μg VEGF/mg total protein, n = 4, p < 0.05) at day 1. At day 3, VEGF secretion was increased as compared to day 1 in control (0.23 ± 0.04  μg VEGF/mg total protein) but it was imbalance by the presence of PFOB emulsion (0.09 ± 0.03 μg VEGF/mg total protein, n = 5, p < 0.05). While insulin secretion was maintained in response to a glucose stimulation test until day 3 when islets were incubated in  the presence of PFOB emulsion preoxygenated (0.81 ± 0.16 at day 1 vs. 0.75 ± 0.24 at day 3), the ability to secrete insulin in the presence of high glucose concentration was lost in islets controls (0.51 ± 0.18 at day 1 vs. 0.21 ± 0.13 at day 3). Atmospheric oxygen  delivery by PFOB emulsion might be sufficient to decrease islets hypoxia. However, to improve islets functionality, overoxygenation is needed. Finally, maintenance of islet viability and functionality for several days after isolation could improve the outcome of islets transplantation.
authors.affiliation: Centre Européen d'Etude du Diabète, Strasbourg, France.
authors.forename: E
authors.initials: E
authors.lastname: Maillard
authors.forename: M T
authors.initials: MT
authors.lastname: Juszczak
authors.forename: A
authors.initials: A
authors.lastname: Langlois
authors.forename: C
authors.initials: C
authors.lastname: Kleiss
authors.forename: M C
authors.initials: MC
authors.lastname: Sencier
authors.forename: W
authors.initials: W
authors.lastname: Bietiger
authors.forename: M
authors.initials: M
authors.lastname: Sanchez-Dominguez
authors.forename: M P
authors.initials: MP
authors.lastname: Krafft
authors.forename: P R V
authors.initials: PR
authors.lastname: Johnson
authors.forename: M
authors.initials: M
authors.lastname: Pinget
authors.forename: S
authors.initials: S
authors.lastname: Sigrist
mesh_terms: D000818:Animals; D015687:Cell Hypoxia / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D005466:Fluorocarbons / Q000494:pharmacology*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D007150:Immunohistochemistry; D050417:Insulin-Secreting Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D007515:Islets of Langerhans / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D005466:Fluorocarbons; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D042461:Vascular Endothelial Growth Factor A