Apolipoprotein A-IV enhances cholecystokinnin secretion.
Physiol Behav
; 188: 11-17, 2018 05 01.
Article
in En
| MEDLINE
| ID: mdl-29378187
ABSTRACT
Cholecystokinin (CCK) and apolipoprotein A-IV (ApoA-IV) are gastrointestinal peptides that play an important role in controlling energy homeostasis. Lymphatic ApoA-IV and plasma CCK secretion are mediated via a chylomicron formation-dependent pathway during a dietary lipid infusion. Given their similar roles as satiating proteins, the present study examines how the two peptides interact in their function. Specifically, this study sought to understand how ApoA-IV regulates CCK secretion. For this purpose, Cck gene expression in the small intestines of ApoA-IV knockout (ApoA-IV-KO) and wild-type (WT) mice were compared under an array of feeding conditions. When fed with a chow or high-fat diet (HFD), basal levels of Cck transcripts were significantly reduced in the duodenum of ApoA-IV-KO mice compared to WT mice. Furthermore, after an oral gavage of a lipid mixture, Cck gene expression in the duodenum was significantly reduced in ApoA-IV-KO mice relative to the change seen in WT mice. To determine the mechanism by which ApoA-IV modulates Cck gene expression, STC-1 cells were transfected with predesigned mouse lysophosphatidic acid receptor 5 (LPAR5) small interfering RNA (siRNA) to knockdown Lpar5 gene expression. In this in-vitro study, mouse recombinant ApoA-IV protein increased Cck gene expression in enteroendocrine STC-1 cells and stimulated CCK release from the STC-1 cells. However, the levels of CCK protein and Cck expression were attenuated when Lpar5 was knocked down in the STC-1 cells. Together these observations suggest that dietary lipid-induced ApoA-IV is associated with Cck synthesis in the duodenum and that ApoA-IV protein directly enhances CCK release through the activation of a LPAR5-dependent pathway.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Apolipoproteins A
/
Cholecystokinin
/
Gene Expression Regulation
/
Duodenum
/
Antioxidants
Limits:
Animals
Language:
En
Journal:
Physiol Behav
Year:
2018
Document type:
Article
Affiliation country:
United States