title: Epoxypukalide induces proliferation and protects against cytokine-mediated apoptosis in primary cultures of pancreatic β-cells.
abstract: There is an urgency to find new treatments for the devastating epidemic of diabetes. Pancreatic β-cells viability and function are impaired in the two most common forms of diabetes, type 1 and type 2. Regeneration of pancreatic β-cells has been proposed as a potential therapy for diabetes. In a preliminary study, we screened a collection of marine products for β-cell proliferation. One unique compound (epoxypukalide) showed capability to induce β-cell replication in the cell line INS1 832/13 and in primary rat cell cultures. Epoxypukalide was used to study β-cell proliferation by [(3)H]thymidine incorporation and BrdU incorporation followed by BrdU/insulin staining in primary cultures of rat islets. AKT and ERK1/2 signalling pathways were analyzed. Cell cycle activators, cyclin D2 and cyclin E, were detected by western-blot. Apoptosis was studied by TUNEL and cleaved caspase 3. β-cell function was measured by glucose-stimulated insulin secretion. Epoxypukalide induced 2.5-fold increase in β-cell proliferation; this effect was mediated by activation of ERK1/2 signalling pathway and upregulation of the cell cycle activators, cyclin D2 and cyclin E. Interestingly, epoxypukalide showed protection from basal (40% lower versus control) and cytokine-induced apoptosis (80% lower versus control). Finally, epoxypukalide did not impair β-cell function when measured by glucose-stimulated insulin secretion. In conclusion, epoxypukalide induces β-cell proliferation and protects against basal and cytokine-mediated β-cell death in primary cultures of rat islets. These findings may be translated into new treatments for diabetes.
authors.affiliation: Instituto de Genética y Biología Molecular-Universidad de Valladolid, Valladolid, Spain.
authors.forename: José Francisco
authors.initials: JF
authors.lastname: López-Acosta
authors.forename: José Luis
authors.initials: JL
authors.lastname: Moreno-Amador
authors.forename: Margarita
authors.initials: M
authors.lastname: Jiménez-Palomares
authors.forename: Ana R
authors.initials: AR
authors.lastname: Díaz-Marrero
authors.forename: Mercedes
authors.initials: M
authors.lastname: Cueto
authors.forename: Germán
authors.initials: G
authors.lastname: Perdomo
authors.forename: Irene
authors.initials: I
authors.lastname: Cózar-Castellano
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000737:chemistry*; D017209:Apoptosis; D002453:Cell Cycle; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D016207:Cytokines / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy; D004305:Dose-Response Relationship, Drug; D007004:Hypoglycemic Agents / Q000494:pharmacology; D050417:Insulin-Secreting Cells / Q000166:cytology* / Q000473:pathology; D007783:Lactones / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D016207:Cytokines; D007004:Hypoglycemic Agents; D007783:Lactones; C044995:11,12-epoxypukalide