In:
Diabetes, Obesity and Metabolism, Wiley, Vol. 19, No. 7 ( 2017-07), p. 997-1005
Abstract:
To test the hypothesis that, given the role of AMP ‐activated protein kinase ( AMPK ) in regulating intracellular ATP levels, AMPK may alter ATP release from astrocytes, the main sources of extracellular ATP ( eATP ) within the brain. Materials and Methods Measurements of ATP release were made from human U373 astrocytoma cells, primary mouse hypothalamic ( HTAS ) and cortical astrocytes ( CRTAS ) and wild‐type and AMPK α1/α2 null mouse embryonic fibroblasts ( MEFs ). Cells were treated with drugs known to modulate AMPK activity: A ‐769662, AICAR and metformin, for up to 3 hours. Intracellular calcium was measured using F luo4 and F ura‐2 calcium‐sensitive fluorescent dyes. Results In U373 cells, A ‐769662 (100 μM) increased AMPK phosphorylation, whereas AICAR and metformin (1 mM) induced a modest increase or had no effect, respectively. Only A ‐769662 increased eATP levels, and this was partially blocked by AMPK inhibitor C ompound C . A‐769662‐induced increases in eATP were preserved in AMPK α1/α2 null MEF cells. A‐769662 increased intracellular calcium in U373 , HTAS and CRTAS cells and chelation of intracellular calcium using BAPTA‐AM reduced A ‐769662‐induced eATP levels. A‐769662 also increased ATP release from a number of other central and peripheral endocrine cell types. Conclusions AMPK is required to maintain basal eATP levels but is not required for A ‐769662‐induced increases in eATP . A‐769662 ( 〉 50 μM) enhanced intracellular calcium levels leading to ATP release in an AMPK and purinergic receptor independent pathway.
Type of Medium:
Online Resource
ISSN:
1462-8902
,
1463-1326
DOI:
10.1111/dom.2017.19.issue-7
Language:
English
Publisher:
Wiley
Publication Date:
2017
detail.hit.zdb_id:
2004918-3
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