PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, v.111, no.49, pp.17612 - 17617
Publisher
NATL ACAD SCIENCES
Abstract
Pancreatic islets secrete hormones that play a key role in regulating
blood glucose levels (glycemia). Age-dependent impairment of
islet function and concomitant dysregulation of glycemia are
major health threats in aged populations. However, the major
causes of the age-dependent decline of islet function are still
disputed. Here we demonstrate that aging of pancreatic islets in
mice and humans is notably associated with inflammation and
fibrosis of islet blood vessels but does not affect glucose sensing
and the insulin secretory capacity of islet beta cells. Accordingly,
when transplanted into the anterior chamber of the eye of young
mice with diabetes, islets from old mice are revascularized with
healthy blood vessels, show strong islet cell proliferation, and fully
restore control of glycemia. Our results indicate that beta cell
function does not decline with age and suggest that islet function
is threatened by an age-dependent impairment of islet vascular
function. Strategies to mitigate age-dependent dysregulation in
glycemia should therefore target systemic and/or local inflammation
and fibrosis of the aged islet vasculature.