Mfge8 regulates enterocyte lipid storage by promoting enterocyte triglyceride hydrolase activity.

TitleMfge8 regulates enterocyte lipid storage by promoting enterocyte triglyceride hydrolase activity.
Publication TypeJournal Article
Year of Publication2016
AuthorsKhalifeh-Soltani A, Gupta D, Ha A, Iqbal J, Hussain M, Podolsky MJ, Atabai K
JournalJCI Insight
Volume1
Issue18
Paginatione87418
Date Published2016 11 03
ISSN2379-3708
KeywordsAnimals, 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.

DOI10.1172/jci.insight.87418
Alternate JournalJCI Insight
PubMed ID27812539
PubMed Central IDPMC5085605
Grant ListR01 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