This study explored the role of irisin as a new pancreatic β-cell secretagogue and survival factor and its potential role in the communication between skeletal muscle and pancreatic β-cells under lipotoxic conditions. Recombinant irisin stimulated insulin biosynthesis and glucose-stimulated insulin secretion (GSIS) in a PKA-dependent manner and prevented saturated fatty acid–induced apoptosis in human and rat pancreatic β-cells, as well as in human and murine pancreatic islets, via AKT/BCL2 signaling. Treatment of myotubes with 0.5 mmol/L palmitate for 4 h, but not with oleate, promoted an increase in irisin release in the culture medium. Moreover, increased serum levels of irisin were observed in mice fed with a high-fat diet. Mouse serum rich in irisin and the conditioned medium from myotubes exposed to palmitate for 4 h significantly reduced apoptosis of murine pancreatic islets and insulin-secreting INS-1E cells, respectively, and this was abrogated in the presence of an irisin-neutralizing antibody. Finally, in vivo administration of irisin improved GSIS and increased β-cell proliferation. In conclusion, irisin can promote β-cell survival and enhance GSIS and may thus participate in the communication between skeletal muscle and β-cells under conditions of excess saturated fatty acids.
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Titolo: | The myokine irisin is released in response to saturated fatty acids and enhances pancreatic beta cell survival and insulin secretion |
Autori: | GIORGINO, Francesco (Corresponding) |
Data di pubblicazione: | 2016 |
Rivista: | |
Abstract: | This study explored the role of irisin as a new pancreatic β-cell secretagogue and survival factor and its potential role in the communication between skeletal muscle and pancreatic β-cells under lipotoxic conditions. Recombinant irisin stimulated insulin biosynthesis and glucose-stimulated insulin secretion (GSIS) in a PKA-dependent manner and prevented saturated fatty acid–induced apoptosis in human and rat pancreatic β-cells, as well as in human and murine pancreatic islets, via AKT/BCL2 signaling. Treatment of myotubes with 0.5 mmol/L palmitate for 4 h, but not with oleate, promoted an increase in irisin release in the culture medium. Moreover, increased serum levels of irisin were observed in mice fed with a high-fat diet. Mouse serum rich in irisin and the conditioned medium from myotubes exposed to palmitate for 4 h significantly reduced apoptosis of murine pancreatic islets and insulin-secreting INS-1E cells, respectively, and this was abrogated in the presence of an irisin-neutralizing antibody. Finally, in vivo administration of irisin improved GSIS and increased β-cell proliferation. In conclusion, irisin can promote β-cell survival and enhance GSIS and may thus participate in the communication between skeletal muscle and β-cells under conditions of excess saturated fatty acids. |
Handle: | http://hdl.handle.net/11586/256079 |
Appare nelle tipologie: | 1.5 Abstract in rivista |