Transcriptional and posttranscriptional regulation of apolipoprotein E, A-I, and A-II gene expression in normal rat liver and during several pathophysiologic states.
Assessment of the relative transcription rates and mRNA steady-state levels for apolipoprotein genes E, A-I, and A-II has been performed in normal rat liver, during liver regeneration and following induction of cirrhosis, as well as in rats with inherited analbuminemia associated with hyperlipidemia. Apo E exhibits primarily transcriptional control with an additional component of posttranscriptional control, whereas Apo A-I is controlled primarily at the posttranscriptional level, thus indicating that these genes are regulated independently. The level of control for Apo A-II has not been determined, because of difficulty experienced in measuring the transcription rate of this gene. During liver regeneration, cirrhosis, and analbuminemia, there is a marked increase in the ratio of Apo A-I to Apo E mRNA, resulting from an increase in the Apo A-I mRNA steady-state level and a decrease in Apo E mRNA. These changes are similar in the three pathophysiologic states and seem to occur through a combination of transcriptional and posttranscriptional mechanisms.
Pandurò
A
A
Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461.
Lin-Lee
Y C
YC
Chan
L
L
Shafritz
D A
DA
D000818:Animals; D016632:Apolipoprotein A-I; D016633:Apolipoprotein A-II; D001054:Apolipoproteins A / Q000096:biosynthesis / Q000235:genetics*; D001057:Apolipoproteins E / Q000096:biosynthesis / Q000235:genetics*; D002252:Carbon Tetrachloride Poisoning / Q000378:metabolism; D056486:Chemical and Drug Induced Liver Injury / Q000209:etiology / Q000378:metabolism; D005786:Gene Expression Regulation; D006949:Hyperlipidemias / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008106:Liver Cirrhosis, Experimental / Q000139:chemically induced / Q000378:metabolism; D008115:Liver Regeneration; D012323:RNA Processing, Post-Transcriptional; D051381:Rats; D011922:Rats, Mutant Strains / Q000378:metabolism; D014158:Transcription, Genetic
D016632:Apolipoprotein A-I; D016633:Apolipoprotein A-II; D001054:Apolipoproteins A; D001057:Apolipoproteins E