scholarly journals Clock regulation of dietary lipid absorption

2012 ◽  
Vol 15 (4) ◽  
pp. 336-341 ◽  
Author(s):  
M. Mahmood Hussain ◽  
Xiaoyue Pan
Keyword(s):  
Dietary Lipid ◽  
Lipid Absorption

Regulation of apo A-IV transcription by lipid in newborn swine is associated with a promoter DNA-binding protein

2003 ◽  
Vol 284 (2) ◽  
pp. G248-G254 ◽  
Author(s):  
Song Lu ◽  
Ying Yao ◽  
Heng Wang ◽  
Songmei Meng ◽  
Xiangying Cheng ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Promoter Sequence ◽  
Dietary Lipid ◽  
Lipid Absorption ◽  
Proximal Promoter ◽  
Significant Shift ◽  
Human Sequence ◽  
Nuclear Extracts ◽  
Promoter Dna ◽  
Isocaloric Diets

Dietary lipid acutely upregulates apolipoprotein (apo) A-IV expression by sevenfold at the pretranslational level in neonatal swine jejunum. To determine the mechanism of this regulation, two-day-old female swine received intraduodenal infusions of low- and high-triacylglycerol (TG) isocaloric diets for 24 h. Nuclear runoff assay confirmed apo A-IV gene transcriptional regulation by the high-TG diet. Footprinting analysis using the swine apo A-IV proximal promoter sequence (+14 to −246 bp) demonstrated three regions protected by the low-TG extracts. Of these three motifs, only ACCTTC showed 100% homology to the human sequence and was further studied. EMSA was performed using probes containing wild-type (WT) and mutant (M) motifs. A shift was noted with the low-TG nuclear extracts with the WT probe but not with the M probe. Excess unlabeled free WT probe competed out the shift, whereas the M probe did not. No significant shift occurred with either probe using high-TG extracts. These results suggest that a repressor protein binds to the ACCTTC motif and becomes unbound during lipid absorption, allowing transcriptional activation of the apo A-IV gene in newborn swine small intestine.

scholarly journals Physiological parameters governing the action of pancreatic lipase

2010 ◽  
Vol 23 (1) ◽  
pp. 146-154 ◽  
Author(s):  
Iain A. Brownlee ◽  
Deborah J. Forster ◽  
Matthew D. Wilcox ◽  
Peter W. Dettmar ◽  
Chris J. Seal ◽  
...  
Keyword(s):  
Weight Management ◽  
Pancreatic Lipase ◽  
Lipase Activity ◽  
Dietary Lipid ◽  
Ion Concentration ◽  
Lipid Absorption ◽  
Energy Yield ◽  
Body Of Knowledge ◽  
Lipid Ester ◽  
Duodenal Lumen

The most widely used pharmacological therapies for obesity and weight management are based on inhibition of gastrointestinal lipases, resulting in a reduced energy yield of ingested foods by reducing dietary lipid absorption. Colipase-dependent pancreatic lipase is believed to be the major gastrointestinal enzyme involved in catalysis of lipid ester bonds. There is scant literature on the action of pancreatic lipase under the range of physiological conditions that occur within the human small intestine, and the literature that does exist is often contradictory. Due to the importance of pancreatic lipase activity to nutrition and weight management, the present review aims to assess the current body of knowledge with regards to the physiology behind the action of this unique gastrointestinal enzyme system. Existing data would suggest that pancreatic lipase activity is affected by intestinal pH, the presence of colipase and bile salts, but not by the physiological range of Ca ion concentration (as is commonly assumed). The control of secretion of pancreatic lipase and its associated factors appears to be driven by gastrointestinal luminal content, particularly the presence of acid or digested proteins and fats in the duodenal lumen. Secretion of colipase, bile acids and pancreatic lipase is driven by cholecystokinin and secretin release.

scholarly journals Is apolipoprotein A-IV rate limiting in the intestinal transport and absorption of triglyceride?

2013 ◽  
Vol 304 (12) ◽  
pp. G1128-G1135 ◽  
Author(s):  
Alison B. Kohan ◽  
Fei Wang ◽  
Xiaoming Li ◽  
Abbey E. Vandersall ◽  
Sarah Huesman ◽  
...  
Keyword(s):  
Intestinal Mucosa ◽  
Dietary Fat ◽  
Intestinal Transport ◽  
Dietary Lipid ◽  
Lipid Absorption ◽  
Lymphatic Transport ◽  
Apolipoprotein A ◽  
Rate Limiting

Apolipoprotein A-IV (apoA-IV) is synthesized by the intestine and secreted when dietary fat is absorbed and transported into lymph associated with chylomicrons. We have recently demonstrated that loss of apoA-IV increases chylomicron size and delays its clearance from the blood. There is still uncertainty, however, about the precise role of apoA-IV on the transport of dietary fat from the intestine into the lymph. ApoA-IV knockout (KO) mice do not have a gross defect in dietary lipid absorption, as measured by oral fat tolerance and fecal fat measurements. Here, using the in vivo lymph fistula mouse model, we show that the cumulative secretion of triglyceride (TG) into lymph in apoA-IV KO mice is very similar to that of wild-type (WT) mice. However, the apoA-IV KO mice do have subtle changes in TG accumulation in the intestinal mucosa during a 6-h continuous, but not bolus, infusion of lipid. There are no changes in the ratio of esterified to free fatty acids in the intestinal mucosa of the apoA-IV KO, however. When we extended these findings, by giving a higher dose of lipid (6 μmol/h) and for a longer infusion period (8 h), we found no effect of apoA-IV KO on intestinal TG absorption. This higher lipid infusion most certainly stresses the intestine, as we see a drastically lower absorption of TG (in both WT and KO mice); however, the loss of A-IV does not exacerbate this effect. This supports our hypothesis that apoA-IV is not required for TG absorption in the intestine. Our data suggest that the mechanisms by which the apoA-IV KO intestine responds to intestinal lipid may not be different from their WT counterparts. We conclude that apoA-IV is not required for normal lymphatic transport of TG.

scholarly journals ACSS2 promotes systemic fat storage and utilization through selective regulation of genes involved in lipid metabolism

2018 ◽  
Vol 115 (40) ◽  
pp. E9499-E9506 ◽  
Author(s):  
Zhiguang Huang ◽  
Menglu Zhang ◽  
Abigail A. Plec ◽  
Sandi Jo Estill ◽  
Ling Cai ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Therapeutic Benefit ◽  
Dietary Lipid ◽  
Lipid Absorption ◽  
Acid Oxidation ◽  
Acetyl Coa ◽  
Adult Mice ◽  
Diet Induced Obesity ◽  
Acetyl Coa Synthesis ◽  
Lipid Transporters

Acetyl-CoA synthetase 2 (ACSS2) is a conserved nucleocytosolic enzyme that converts acetate to acetyl-CoA. Adult mice lacking ACSS2 appear phenotypically normal but exhibit reduced tumor burdens in mouse models of liver cancer. The normal physiological functions of this alternate pathway of acetyl-CoA synthesis remain unclear, however. Here, we reveal that mice lacking ACSS2 exhibit a significant reduction in body weight and hepatic steatosis in a diet-induced obesity model. ACSS2 deficiency reduces dietary lipid absorption by the intestine and also perturbs repartitioning and utilization of triglycerides from adipose tissue to the liver due to lowered expression of lipid transporters and fatty acid oxidation genes. In this manner, ACSS2 promotes the systemic storage or metabolism of fat according to the fed or fasted state through the selective regulation of genes involved in lipid metabolism. Thus, targeting ACSS2 may offer a therapeutic benefit for the treatment of fatty liver disease.

Histological organization of intestinal villi in the crocodilian caiman yacare (Daudin, 1802) during dietary lipid absorption

Zoomorphology ◽  
2018 ◽  
Vol 137 (3) ◽  
pp. 419-432
Author(s):  
Ricardo Moraes Borges ◽  
Leandro Nogueira Pressinotti ◽  
Francisco Alberto Marcus ◽  
Renata Stecca Iunes ◽  
Victor Manuel Aleixo ◽  
...  
Keyword(s):  
Dietary Lipid ◽  
Lipid Absorption ◽  
Intestinal Villi

Dietary lipid absorption and lipoprotein secretion by the intestine of the crocodilian Caiman yacare (Daudin, 1802)

Zoomorphology ◽  
2016 ◽  
Vol 135 (2) ◽  
pp. 217-231 ◽  
Author(s):  
Ricardo Moraes Borges ◽  
Leandro Nogueira Pressinotti ◽  
Victor Manuel Aleixo ◽  
João Carlos Shimada Borges ◽  
Alessandro Spíndola Bérgamo ◽  
...  
Keyword(s):  
Dietary Lipid ◽  
Lipid Absorption ◽  
Lipoprotein Secretion

β-sitosterol as a nonabsorbable marker of dietary lipid absorption in man

1978 ◽  
Vol 89 (2) ◽  
pp. 331-339 ◽  
Author(s):  
Douglas F. Newton ◽  
Charles M. Mansbach
Keyword(s):  
Dietary Lipid ◽  
Lipid Absorption

Hepatocyte nuclear factor-4 mediates apolipoprotein A-IV transcriptional regulation by fatty acid in newborn swine enterocytes

2007 ◽  
Vol 293 (2) ◽  
pp. G475-G483 ◽  
Author(s):  
Shuangying Leng ◽  
Song Lu ◽  
Ying Yao ◽  
Zhisheng Kan ◽  
Gabriel S. Morris ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Large Subunit ◽  
Dietary Lipid ◽  
Lipid Absorption ◽  
Luciferase Reporter ◽  
Mrna Levels ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Luciferase Reporter Gene

Hepatocyte nuclear factor-4α (HNF-4α) regulates transcription of several genes involved in lipid metabolism, including that of apolipoprotein (apo) A-IV, which is tightly regulated by lipid absorption and enhances enterocyte chylomicron secretion. Studies were performed to define the role of HNF-4α in the regulation of apo A-IV gene transcription by dietary fatty acid in neonatal swine small intestine. HNF-4α mRNA was expressed in liver > intestine > kidney in suckling, weanling, and weaned pigs. Jejunal HNF-4α mRNA and protein and apo A-IV and swine microsomal triglyceride transfer protein (MTP) large subunit mRNA expression were induced in parallel in 2-day-old swine by a 24-h high-fat intraduodenal infusion. In IPEC-1 cells, incubation with oleic acid (OA) resulted in coordinate induction of both HNF-4α, apo A-IV, and MTP mRNA, similar to that observed in vivo. When HNF-4α expression was driven by doxycycline by using the TET-On system in the absence of OA to observe the effect of HNF-4α directly on apo A-IV and MTP mRNA levels in the absence of other factors that might be concomitantly induced by fatty acid absorption, apo A-IV and MTP expression were increased. In luciferase reporter gene assays in IPEC-1 cells using apo A-IV/C-III intergenic region constructs, TET-On-regulated HNF-4α expression without OA increased luciferase activity, and incubation with OA did not further increase activity. These data suggest that acute induction of the apo A-IV and MTP genes by dietary lipid in newborn intestine occurs, at least in part, via ligand-independent transactivation by HNF-4α that is itself induced by a lipid-mediated mechanism.

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