Title | Mfge8 regulates enterocyte lipid storage by promoting enterocyte triglyceride hydrolase activity. |
Publication Type | Journal Article |
Year of Publication | 2016 |
Authors | Khalifeh-Soltani A, Gupta D, Ha A, Iqbal J, Hussain M, Podolsky MJ, Atabai K |
Journal | JCI Insight |
Volume | 1 |
Issue | 18 |
Pagination | e87418 |
Date Published | 2016 11 03 |
ISSN | 2379-3708 |
Keywords | Animals, Antigens, Surface, Caco-2 Cells, Chylomicrons, Enterocytes, Humans, Hydrolases, Integrin alphaVbeta3, Lipid Metabolism, Mice, Mice, Inbred C57BL, Mice, Knockout, Milk Proteins, Receptors, Vitronectin, Triglycerides |
Abstract | The small intestine has an underappreciated role as a lipid storage organ. Under conditions of high dietary fat intake, enterocytes can minimize the extent of postprandial lipemia by storing newly absorbed dietary fat in cytoplasmic lipid droplets. Lipid droplets can be subsequently mobilized for the production of chylomicrons. The mechanisms that regulate this process are poorly understood. We report here that the milk protein Mfge8 regulates hydrolysis of cytoplasmic lipid droplets in enterocytes after interacting with the αvβ3 and αvβ5 integrins. Mice deficient in Mfge8 or the αvβ3 and αvβ5 integrins accumulate excess cytoplasmic lipid droplets after a fat challenge. Mechanistically, interruption of the Mfge8-integrin axis leads to impaired enterocyte intracellular triglyceride hydrolase activity in vitro and in vivo. Furthermore, Mfge8 increases triglyceride hydrolase activity through a PI3 kinase/mTORC2-dependent signaling pathway. These data identify a key role for Mfge8 and the αvβ3 and αvβ5 integrins in regulating enterocyte lipid processing. |
DOI | 10.1172/jci.insight.87418 |
Alternate Journal | JCI Insight |
PubMed ID | 27812539 |
PubMed Central ID | PMC5085605 |
Grant List | R01 DK081879 / DK / NIDDK NIH HHS / United States R01 DK046900 / DK / NIDDK NIH HHS / United States P30 DK098722 / DK / NIDDK NIH HHS / United States R29 DK046900 / DK / NIDDK NIH HHS / United States R01 DK110098 / DK / NIDDK NIH HHS / United States R56 DK046900 / DK / NIDDK NIH HHS / United States |