Alteration of mitochondrial function and insulin sensitivity in primary mouse skeletal muscle cells isolated from transgenic and knockout mice: role of ogg1.

Abstract:

:Recent evidence has linked mitochondrial dysfunction and DNA damage, increased oxidative stress in skeletal muscle, and insulin resistance (IR). The purpose of this study was to determine the role of the DNA repair enzyme, human 8-oxoguanine DNA glycosylase/apurinic/apyrimidinic lyase (hOGG1), on palmitate-induced mitochondrial dysfunction and IR in primary cultures of skeletal muscle derived from hind limb of ogg1(-/-) knockout mice and transgenic mice, which overexpress human (hOGG1) in mitochondria (transgenic [Tg]/MTS-hOGG1). Following exposure to palmitate, we evaluated mitochondrial DNA (mtDNA) damage, mitochondrial function, production of mitochondrial reactive oxygen species (mtROS), mitochondrial mass, JNK activation, insulin signaling pathways, and glucose uptake. Palmitate-induced mtDNA damage, mtROS, mitochondrial dysfunction, and activation of JNK were all diminished, whereas ATP levels, mitochondrial mass, insulin-stimulated phosphorylation of Akt (Ser 473), and insulin sensitivity were increased in primary myotubes isolated from Tg/MTS-hOGG1 mice compared to myotubes isolated from either knockout or wild-type mice. In addition, both basal and maximal respiratory rates during mitochondrial oxidation on pyruvate showed a variable response, with some animals displaying an increased respiration in muscle fibers isolated from the transgenic mice. Our results support the model that DNA repair enzyme OGG1 plays a pivotal role in repairing mtDNA damage, and consequently, in mtROS production and regulating downstream events leading to IR in skeletal muscle.

journal_name

Endocrinology

journal_title

Endocrinology

authors

Yuzefovych LV,Schuler AM,Chen J,Alvarez DF,Eide L,Ledoux SP,Wilson GL,Rachek LI

doi

10.1210/en.2013-1076

subject

Has Abstract

pub_date

2013-08-01 00:00:00

pages

2640-9

issue

8

eissn

0013-7227

issn

1945-7170

pii

en.2013-1076

journal_volume

154

pub_type

杂志文章