Endothelial microparticles released by activated protein C protect beta cells through EPCR/PAR1 and annexin A1/FPR2 pathways in islets.
Fiche publication
Date publication
novembre 2017
Journal
Journal of cellular and molecular medicine
Auteurs
Membres identifiés du Cancéropôle Est :
Pr UBEAUD-SEQUIER Genevieve, Dr BALTZINGER Philippe
Tous les auteurs :
Kreutter G, Kassem M, El Habhab A, Baltzinger P, Abbas M, Boisrame-Helms J, Amoura L, Peluso J, Yver B, Fatiha Z, Ubeaud-Sequier G, Kessler L, Toti F
Lien Pubmed
Résumé
Islet transplantation is associated with early ischaemia/reperfusion, localized coagulation and redox-sensitive endothelial dysfunction. In animal models, islet cytoprotection by activated protein C (aPC) restores islet vascularization and protects graft function, suggesting that aPC triggers various lineages. aPC also prompts the release of endothelial MP that bear EPCR, its specific receptor. Microparticles (MP) are plasma membrane procoagulant vesicles, surrogate markers of stress and cellular effectors. We measured the cytoprotective effects of aPC on endothelial and insulin-secreting Rin-m5f β-cells and its role in autocrine and paracrine MP-mediated cell crosstalk under conditions of oxidative stress. MP from aPC-treated primary endothelial (EC) or β-cells were applied to H O -treated Rin-m5f. aPC activity was measured by enzymatic assay and ROS species by dihydroethidium. The capture of PKH26-stained MP and the expression of EPCR were probed by fluorescence microscopy and apoptosis by flow cytometry. aPC treatment enhanced both annexin A1 (ANXA1) and PAR-1 expression in EC and to a lesser extent in β-cells. MP from aPC-treated EC (eM ) exhibited high EPCR and annexin A1 content, protected β-cells, restored insulin secretion and were captured by 80% of β cells in a phosphatidylserine and ANXA1-dependent mechanism. eMP activated EPCR/PAR-1 and ANXA1/FPR2-dependent pathways and up-regulated the expression of EPCR, and of FPR2/ALX, the ANXA1 receptor. Cytoprotection was confirmed in H O -treated rat islets with increased viability (62% versus 48% H O ), reduced apoptosis and preserved insulin secretion in response to glucose elevation (16 versus 5 ng/ml insulin per 10 islets). MP may prove a promising therapeutic tool in the protection of transplanted islets.
Mots clés
Animals, Annexin A1, genetics, Cell Line, Cell-Derived Microparticles, chemistry, Coronary Vessels, chemistry, Endothelial Cells, chemistry, Gene Expression Regulation, Hydrogen Peroxide, antagonists & inhibitors, Insulin-Secreting Cells, cytology, Islets of Langerhans, cytology, Primary Cell Culture, Protective Agents, pharmacology, Protein C, pharmacology, Protein-Serine-Threonine Kinases, genetics, Rats, Receptors, Endothelin, genetics, Receptors, Lipoxin, genetics, Signal Transduction, Swine, Tissue Culture Techniques
Référence
J. Cell. Mol. Med.. 2017 Nov;21(11):2759-2772