scholarly journals Microsomal Triglyceride Transfer Protein Activity Is Not Required for the Initiation of Apolipoprotein B-containing Lipoprotein Assembly in McA-RH7777 Cells

2007 ◽  
Vol 282 (39) ◽  
pp. 28597-28608 ◽  
Author(s):  
Nassrin Dashti ◽  
Medha Manchekar ◽  
Yanwen Liu ◽  
Zhihuan Sun ◽  
Jere P. Segrest
Keyword(s):  
Apolipoprotein B ◽  
Microsomal Triglyceride Transfer Protein ◽  
Protein Activity ◽  
Transfer Protein ◽  
Lipoprotein Assembly

scholarly journals Apolipoprotein B-containing lipoprotein assembly in microsomal triglyceride transfer protein-deficient McA-RH7777 cells

2010 ◽  
Vol 51 (8) ◽  
pp. 2253-2264 ◽  
Author(s):  
Yanwen Liu ◽  
Medha Manchekar ◽  
Zhihuan Sun ◽  
Paul E. Richardson ◽  
Nassrin Dashti
Keyword(s):  
Apolipoprotein B ◽  
Microsomal Triglyceride Transfer Protein ◽  
Transfer Protein ◽  
Lipoprotein Assembly

Immunolocalization, ontogeny, and regulation of microsomal triglyceride transfer protein in human fetal intestine

2001 ◽  
Vol 280 (4) ◽  
pp. G563-G571 ◽  
Author(s):  
E. Levy ◽  
S. Stan ◽  
C. Garofalo ◽  
E. E. Delvin ◽  
E. G. Seidman ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Epithelial Cells ◽  
Lipid Production ◽  
Regional Distribution ◽  
Microsomal Triglyceride Transfer Protein ◽  
Quantitative Information ◽  
Transfer Protein ◽  
Proximal Small Intestine ◽  
Lipoprotein Assembly ◽  
Fetal Intestine

To examine the multiple stages of lipoprotein packaging during development, we studied localization, ontogeny, and regulation of microsomal transfer protein (MTP), a crucial protein for lipid transport. With the use of immunofluorescence, MTP was identified in villus and crypt epithelial cells in different regions of human fetal intestine, including colon. Staining was detected as early as the 13th wk of gestation in all gut segments and was almost entirely confined to the columnar epithelial cells of the jejunum and colon. Unlike immunofluorescence, which provides qualitative but not quantitative information on MTP signal, enzymatic assays revealed a decreasing gradient from proximal small intestine to distal, as confirmed by immunoblot. Activity of MTP in small intestinal explants cultured for different incubation periods (0, 4, 8, and 24 h) peaked at 4 h but remained insensitive to different concentrations of oleic acid. Also, a trend toward increasing MTP activity was observed at 20–22 wk of gestation. Finally, in strong contrast to jejunal efficiency, colonic explants displayed impaired lipid production, apolipoprotein biogenesis, and lipoprotein assembly, in association with poor expression of MTP. These findings provide the first evidence that human fetal gut is able to express MTP and emphasize the distinct regional distribution, regulation by oleic acid, and ontogeny of MTP.

Development and Physiological Regulation of Intestinal Lipid Absorption. I. Development of intestinal lipid absorption: cellular events in chylomicron assembly and secretion

2007 ◽  
Vol 293 (3) ◽  
pp. G519-G524 ◽  
Author(s):  
Dennis D. Black
Keyword(s):  
Dietary Fat ◽  
Apolipoprotein B ◽  
Microsomal Triglyceride Transfer Protein ◽  
Lipid Absorption ◽  
Cellular Mechanisms ◽  
Peripheral Tissues ◽  
Physiological Regulation ◽  
Transfer Protein ◽  
Cellular Events ◽  
Apolipoprotein A

The newborn mammal must efficiently absorb dietary fat, predominantly as triacylglycerol, and produce chylomicrons to deliver this lipid to peripheral tissues. The cellular mechanisms involved in enterocyte chylomicron assembly have recently been elucidated, and data on their regulation in the immature gut are beginning to emerge. This review focuses on key proteins involved in chylomicron assembly: apolipoprotein B-48, microsomal triglyceride transfer protein, and apolipoproten A-IV. Recent studies support a role for apolipoprotein A-IV in enhancing chylomicron secretion by promoting production of larger particles. These proteins are regulated in a manner to maximize the lipid absorptive capacity of the newborn intestine.

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