Chronic fractalkine administration improves glucose tolerance and pancreatic endocrine function.

ABSTRACT: We have previously reported that the fractalkine (FKN)/CX3CR1 system represents a novel regulatory mechanism for insulin secretion and ? cell function. Here, we demonstrate that chronic administration of a long-acting form of FKN, FKN-Fc, can exert durable effects to improve glucose tolerance with increased glucose-stimulated insulin secretion and decreased ? cell apoptosis in obese rodent models. Unexpectedly, chronic FKN-Fc administration also led to decreased ? cell glucagon secretion. In islet cells, FKN inhibited ATP-sensitive potassium channel conductance by an ERK-dependent mechanism, which triggered ? cell action potential (AP) firing and decreased ? cell AP amplitude. This results in increased glucose-stimulated insulin secretion and decreased glucagon secretion. Beyond its islet effects, FKN-Fc also exerted peripheral effects to enhance hepatic insulin sensitivity due to inhibition of glucagon action. In hepatocytes, FKN treatment reduced glucagon-stimulated cAMP production and CREB phosphorylation in a pertussis toxin-sensitive manner. Together, these results raise the possibility of use of FKN-based therapy to improve type 2 diabetes by increasing both insulin secretion and insulin sensitivity.

SUBMITTER: Riopel M 

PROVIDER: S-EPMC5873865 | biostudies-other | 2018 Apr

REPOSITORIES: biostudies-other