1. UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Bld René Leriche, 67200 Strasbourg, France
2. ICube UMR 7357, Université de Strasbourg, CNRS, IMIS, 4 rue Kirschleger, 67085 Strasbourg, France
3. Service de Biophysique et Médecine Nucléaire, Hôpitaux Universitaires de Strasbourg, 1 avenue Molière, 67100 Strasbourg, France
4. Fédération de Médecine Translationnelle de Strasbourg (FMTS), Faculté de médecine, Strasbourg, France
5. Service d'Endocrinologie - Diabète et Maladies métaboliques, Hôpitaux Universitaires de Strasbourg, 1 place de l'Hôpital, 67091 Strasbourg, France
6. UMR 7034 CNRS, Faculté de Pharmacie, Université de Strasbourg, 67 401 Illkirch, France
7. Laboratoire de biochimie et biologie moléculaire, Hôpitaux Universitaires de Strasbourg, 1 place de l'Hôpital, 67091 Strasbourg, France.
Intrahepatic transplantation of islets requires a lot of islets because more than 50% of the graft is lost during the 24 hours following transplantation. We analyzed, in a rat model, early post-transplantation inflammation using systemic inflammatory markers, or directly in islet-transplanted livers by immunohistochemistry. 1H HRMAS NMR was employed to investigate metabolic responses associated with the transplantation. Inflammatory markers (Interleukin-6, α2-macroglobulin) are not suitable to follow islet reactions as they are not islet specific. To study islet specific inflammatory events, immunohistochemistry was performed on sections of islet transplanted livers for thrombin (indicator of the instant blood-mediated inflammatory reaction (IBMIR)) and granulocytes and macrophages. We observed a specific correlation between IBMIR and granulocyte and macrophage infiltration after 12 h. In parallel, we identified a metabolic response associated with transplantation: after 12 h, glucose, alanine, aspartate, glutamate and glutathione were significantly increased. An increase of glucose is a marker of tissue degradation, and could be explained by immune cell infiltration. Alanine, aspartate and glutamate are inter-connected in a common metabolic pathway known to be activated during hypoxia. An increase of glutathione revealed the presence of antioxidant protection. In this study, IBMIR visualization combined with 1H HRMAS NMR facilitated the characterization of cellular and molecular pathways recruited following islet transplantation.
Keywords: 1H NMR, metabolomics, histology, islet transplantation, liver.