Human islet preparations distributed for research exhibit a variety of insulin-secretory profiles

Abstract

Powers AC. Human islet preparations distributed for research exhibit a variety of insulin-secretory profiles. Am J Physiol Endocrinol Metab 308: E592-E602, 2015. First published February 3, 2015 doi:10.1152/ajpendo.00437.2014.-Human islet research is providing new insights into human islet biology and diabetes, using islets isolated at multiple US centers from donors with varying characteristics. This creates challenges for understanding, interpreting, and integrating research findings from the many laboratories that use these islets. In what is, to our knowledge, the first standardized assessment of human islet preparations from multiple isolation centers, we measured insulin secretion from 202 preparations isolated at 15 centers over 11 years and noted five distinct patterns of insulin secretion. Approximately three quarters were appropriately responsive to stimuli, but one quarter were dysfunctional, with unstable basal insulin secretion and/or an impairment in stimulated insulin secretion. Importantly, the patterns of insulin secretion by responsive human islet preparations (stable Baseline and Fold stimulation of insulin secretion) isolated at different centers were similar and improved slightly over the years studied. When all preparations studied were considered, basal and stimulated insulin secretion did not correlate with isolation center, biological differences of the islet donor, or differences in isolation, such as Cold Ischemia Time. Dysfunctional islet preparations could not be predicted from the information provided by the isolation center and had altered expression of genes encoding components of the glucose-sensing pathway, but not of insulin production or cell death. These results indicate that insulin secretion by most preparations from multiple centers is similar but that in vitro responsiveness of human islets cannot be predicted, necessitating preexperimental human islet assessment. These results should be considered when one is designing, interpreting, and integrating experiments using human islets.human; islet; function THE AVAILABILITY OF HUMAN ISLETS for basic and translational research has increased markedly over the past decade, fueling insights into human islet biology and diabetes. Studies of human islets have provided insight into human islet morphology, ␤-cell proliferation (2, 5, 6, 12), epigenetics (2, 4 -6, 12, 22

Beta-cell hubs maintain Ca2+ oscillations in human and mouse islet simulations

“…Although models of human β-cells exist 50,72,73 which capture the different electrophysiological properties of these cells compared to rodent β-cells 50,72-75 , there is large variability in the quality, function and donor details of human islets. 76-78 Furthermore, the data that these models are based on uses recordings from dispersed human β-cells that were cultured in media without the addition of any serum. 50,73,74 It has subsequently been shown that supplementation of islets with serum is essential for preserving islet function.…”

Age-dependent human β cell proliferation induced by glucagon-like peptide 1 and calcineurin signaling

“…Islets from 12 adult donors (ages 20,21,29,30,40,43,43,48,49,53,60, and 60 years, BMI ranges 24.1-29.6) were obtained from the Integrated Islet Distribution Program (http://iidp.coh.org). Islet function (i.e., glucose-induced insulin secretion) was assessed by islet perifusion assay on the day of arrival, as previously described (57,58). Each human islet preparation was handpicked on the day of arrival for gene expression studies (57).…”

Cystic fibrosis–related diabetes is caused by islet loss and inflammation

“…All samples were stored at -80°C until insulin measurement by radioimmunoassay from Millipore (catalog no. RI-13K) (32,71).…”

“…Human islets were perifused within 24 hours of arrival at Vanderbilt, as previously described (32,71,76), with DMEM supplemented with the following glucose concentrations and test agents: 5.6 mM glucose, 16.7 mM glucose, 16.7 mM glucose plus 100 μm IBMX, 1.7 mM glucose plus 1 μm epinephrine (MilliporeSigma), and 5.6 mM glucose plus 20 mM KCl (MilliporeSigma). Human insulin and glucagon secretion and content was measured in fractions and extracts by radioimmunoassay from MilliporeSigma (catalog no.…”

“…Human insulin and glucagon secretion and content was measured in fractions and extracts by radioimmunoassay from MilliporeSigma (catalog no. RI-13K and GL-32K) (32,71). Data were normalized to IEQ, total content, maximum KCl response, maximum IBMX response, and in the case of glucagon, 1.7 mM glucose + 1 μm epinephrine.…”