Co-regulation of apo A-I, apo C-III and apo A-IV gene expression in human intestinal biopsies.
The apo A-I gene is expressed in the liver and small intestine. In order to study the role of human intestinal transcription of the apo A-I gene in determining plasma high-density lipoprotein, (HDL)-cholesterol and apo lipoprotein (apo) A-I concentrations, the authors measured the relative mRNA levels of apo A-I in human intestinal biopsies. Biopsies were taken from 50 fasting subjects (25 males and 25 females). At the same time blood was taken for lipid and lipoprotein analysis. Plasma HDL-cholesterol correlated linearly with plasma apo A-I protein. No correlation could be demonstrated between intestinal apo A-I mRNA and plasma apo A-I or HDL-cholesterol levels. The apo A-I gene resides in an apolipoprotein cluster with the apo C-III and apo A-IV genes. To assess whether there is a coordinated expression of this locus, Northern blot analysis of intestinal RNA was performed. The authors have demonstrated that under fasting conditions mRNA levels of apo A-I, C-III and A-IV are co-regulated in the intestine.
Metzger
S
S
Division of Medicine, Hadassah University Hospital, Jerusalem, Israel.
Levy
Y
Y
Arnon
R
R
Chajek-Shaul
T
T
D000328:Adult; D000368:Aged; D016632:Apolipoprotein A-I / Q000097:blood / Q000235:genetics*; D053305:Apolipoprotein C-III; D001054:Apolipoproteins A / Q000235:genetics*; D001056:Apolipoproteins C / Q000235:genetics*; D001706:Biopsy; D015152:Blotting, Northern; D008076:Cholesterol, HDL / Q000097:blood; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D014280:Triglycerides / Q000097:blood
D016632:Apolipoprotein A-I; D053305:Apolipoprotein C-III; D001054:Apolipoproteins A; D001056:Apolipoproteins C; D008076:Cholesterol, HDL; D012333:RNA, Messenger; D014280:Triglycerides; C022205:apolipoprotein A-IV