[HTML][HTML] A novel high-throughput assay for islet respiration reveals uncoupling of rodent and human islets

JD Wikstrom, SB Sereda, L Stiles, A Elorza, EM Allister… - PloS one, 2012 - journals.plos.org
JD Wikstrom, SB Sereda, L Stiles, A Elorza, EM Allister, A Neilson, DA Ferrick, MB Wheeler…
PloS one, 2012journals.plos.org
Background The pancreatic beta cell is unique in its response to nutrient by increased fuel
oxidation. Recent studies have demonstrated that oxygen consumption rate (OCR) may be a
valuable predictor of islet quality and long term nutrient responsiveness. To date, high-
throughput and user-friendly assays for islet respiration are lacking. The aim of this study
was to develop such an assay and to examine bioenergetic efficiency of rodent and human
islets. Methodology/Principal Findings The XF24 respirometer platform was adapted to islets …
Background
The pancreatic beta cell is unique in its response to nutrient by increased fuel oxidation. Recent studies have demonstrated that oxygen consumption rate (OCR) may be a valuable predictor of islet quality and long term nutrient responsiveness. To date, high-throughput and user-friendly assays for islet respiration are lacking. The aim of this study was to develop such an assay and to examine bioenergetic efficiency of rodent and human islets.
Methodology/Principal Findings
The XF24 respirometer platform was adapted to islets by the development of a 24-well plate specifically designed to confine islets. The islet plate generated data with low inter-well variability and enabled stable measurement of oxygen consumption for hours. The F1F0 ATP synthase blocker oligomycin was used to assess uncoupling while rotenone together with myxothiazol/antimycin was used to measure the level of non-mitochondrial respiration. The use of oligomycin in islets was validated by reversing its effect in the presence of the uncoupler FCCP. Respiratory leak averaged to 59% and 49% of basal OCR in islets from C57Bl6/J and FVB/N mice, respectively. In comparison, respiratory leak of INS-1 cells and C2C12 myotubes was measured to 38% and 23% respectively. Islets from a cohort of human donors showed a respiratory leak of 38%, significantly lower than mouse islets.
Conclusions/Significance
The assay for islet respiration presented here provides a novel tool that can be used to study islet mitochondrial function in a relatively high-throughput manner. The data obtained in this study shows that rodent islets are less bioenergetically efficient than human islets as well as INS1 cells.
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