Overexpression of lactate dehydrogenase A attenuates glucose‐induced insulin secretion in stable MIN‐6 β‐cell lines

FEBS Letters

Rutter, Guy A¹  Zhao, Chao¹ 

[1] Department of Biochemistry, School of Medical Sciences, University Walk, University of Bristol, Bristol BS8 1TD, UK

关键词: Islet β-cell;    Lactate dehydrogenase;    Insulin secretion;    MIN6;    LDH;    lactate dehydrogenase;    GPDHm;    mitochondrial glycerol phosphate dehydrogenase;    KRBH;    Krebs-Ringer-bicarbonate-HEPES medium;    pHi;    intracellular pH;   

DOI  :  10.1016/S0014-5793(98)00600-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Since islet β-cells express little l-lactate dehydrogenase (LDH) activity, we have examined the effects on these cells of LDH overexpression. In mock-transfected MIN6 β-cells, LDH activity was 38 nmol/min/mg protein, and 30 mM glucose stimulated secretion 10.4-fold. In two MIN6 cell clones stably overexpressing human LDH-A cDNA, insulin secretion was stimulated only 2.7- and 2.1-fold by high glucose. K⁺-stimulated insulin secretion was unaffected, and leucine stimulation enhanced, by LDH-A overexpression. LDH-A-overexpressing clones displayed unaltered activities of hexokinase, glucokinase, and malate dehydrogenase, slightly elevated plasma membrane lactate transport activity, and lowered insulin content. Low LDH activity would therefore appear important in β-cell glucose sensing.

【 授权许可】

Unknown