Regulation of intestinal and hypothalamic apolipoprotein A-IV.
This review discusses the regulation of the intestinal and hypothalamic apolipoprotein A-IV (apo A-IV) gene and protein expression. Apo A-IV is a glycoprotein secreted together with triglyceride-rich lipoproteins by the small intestine. Intestinal apo A-IV synthesis is stimulated by fat absorption, probably mediated by chylomicron formation. This stimulation of intestinal apo A-IV synthesis is attenuated by intravenous leptin infusion. Chronic ingestion of a high-fat diet blunts the intestinal apo A-IV in response to dietary lipid. Intestinal apo A-IV synthesis is also stimulated by members of the pancreatic polypeptide family, including peptide YY (PYY), neuropeptide Y (NPY), and pancreatic polypeptide (PP). Recently, apo A-IV was demonstrated to be present in the hypothalamus as well. Hypothalamic apo A-IV level was reduced by food deprivation and restored by lipid feeding. Intracerebroventricular administration of apo A-IV antiserum stimulated feeding and decreased the hypothalamic apo A-IV mRNA level, implying that feeding is intimately regulated by endogenous hypothalamic apo A-IV. Central administration of NPY significantly increased hypothalamic apo A-IV mRNA levels in a dose-dependent manner.
Liu
Min
M
Department of Pathology and Laboratory Medicine, University of Cincinnati Medical College, Cincinnati, Ohio 45267-0529, USA.
Doi
Takashi
T
Tso
Patrick
P
D000818:Animals; D001054:Apolipoproteins A / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004041:Dietary Fats / Q000378:metabolism / Q000494:pharmacology; D005215:Fasting / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism*; D020738:Leptin / Q000494:pharmacology; D008055:Lipids / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D014628:Vagotomy
D001054:Apolipoproteins A; D004041:Dietary Fats; D020738:Leptin; D008055:Lipids; D010455:Peptides; C022205:apolipoprotein A-IV