Copper deficiency increases hepatic apolipoprotein B secretion and mRNA editing in rats.
Male weanling Sprague-Dawley rats were assigned to copper-deficient (9.0 mumol Cu/kg diet) or copper-adequate (102 mumol Cu/kg diet) dietary treatments for 6 wk. Pulse-chase studies using freshly isolated rat liver parenchymal cells demonstrated that apolipoprotein B (apoB)-48 and apoB-100 syntheses were not altered, but secretion was increased twofold in hepatocytes derived from copper-deficient rats. Both plasma apoB-48 and apoB-100 levels were increased by copper deficiency, but only the apoB-48 increase was significant. Hepatic apoB mRNA editing, expressed as a ratio of apoB-48 mRNA to apoB-48 plus apoB-100 mRNA, was significantly increased from 60.8% in copper-adequate to 70.2% in copper-deficient rats. Moreover, hepatic apoB mRNA abundance was not significantly altered by copper deficiency. Thus the increased amount of nascent apoB-48 secreted into the medium as well as the enhanced apoB mRNA editing may have contributed to the differential increase in plasma apoB-48 over apoB-100 level in copper-deficient rats.
Reaves
S K
SK
Department of Nutritional Sciences, University of Arizona, Tucson 85721, USA.
Hoogeveen
R C
RC
Wang
Y R
YR
Wu
J Y
JY
Lei
K Y
KY
D000818:Animals; D053299:Apolipoprotein B-100; D053283:Apolipoprotein B-48; D001055:Apolipoproteins B / Q000097:blood / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D003300:Copper / Q000172:deficiency*; D008099:Liver / Q000378:metabolism*; D008297:Male; D015335:Molecular Probes / Q000235:genetics; D008969:Molecular Sequence Data; D017393:RNA Editing; D051381:Rats; D017207:Rats, Sprague-Dawley
D053299:Apolipoprotein B-100; D053283:Apolipoprotein B-48; D001055:Apolipoproteins B; D015335:Molecular Probes; D003300:Copper